diff --git a/third_party/BUILD b/third_party/BUILD index a100a2ca1ae..4b80dd42d50 100644 --- a/third_party/BUILD +++ b/third_party/BUILD @@ -18,6 +18,7 @@ filegroup( "//third_party/forked/etcd237/pkg/fileutil:all-srcs", "//third_party/forked/etcd237/wal:all-srcs", "//third_party/forked/golang/expansion:all-srcs", + "//third_party/forked/golang/go/types:all-srcs", "//third_party/forked/golang/reflect:all-srcs", "//third_party/forked/golang/template:all-srcs", "//third_party/forked/gonum/graph:all-srcs", diff --git a/third_party/forked/golang/go/types/BUILD b/third_party/forked/golang/go/types/BUILD new file mode 100644 index 00000000000..df42eff853d --- /dev/null +++ b/third_party/forked/golang/go/types/BUILD @@ -0,0 +1,56 @@ +licenses(["notice"]) + +load("@io_bazel_rules_go//go:def.bzl", "go_library") + +go_library( + name = "go_default_library", + srcs = [ + "api.go", + "assignments.go", + "builtins.go", + "call.go", + "check.go", + "conversions.go", + "decl.go", + "errors.go", + "eval.go", + "expr.go", + "exprstring.go", + "initorder.go", + "labels.go", + "lookup.go", + "methodset.go", + "object.go", + "objset.go", + "operand.go", + "ordering.go", + "package.go", + "predicates.go", + "resolver.go", + "return.go", + "scope.go", + "selection.go", + "sizes.go", + "stmt.go", + "type.go", + "typestring.go", + "typexpr.go", + "universe.go", + ], + importpath = "k8s.io/kubernetes/third_party/forked/golang/go/types", + visibility = ["//visibility:public"], +) + +filegroup( + name = "package-srcs", + srcs = glob(["**"]), + tags = ["automanaged"], + visibility = ["//visibility:private"], +) + +filegroup( + name = "all-srcs", + srcs = [":package-srcs"], + tags = ["automanaged"], + visibility = ["//visibility:public"], +) diff --git a/third_party/forked/golang/go/types/README b/third_party/forked/golang/go/types/README new file mode 100644 index 00000000000..c0c93fef360 --- /dev/null +++ b/third_party/forked/golang/go/types/README @@ -0,0 +1,7 @@ +This is go/types forked from go@236abdb46b (just after 1.10) and cherry-picked +1006f703ffc, which fixes https://github.com/golang/go/issues/23712. + +It can be removed when all builders are >= go1.11. + +Do *not* update this to newer code if https://github.com/golang/go/issues/23914 +has not been fixed! diff --git a/third_party/forked/golang/go/types/api.go b/third_party/forked/golang/go/types/api.go new file mode 100644 index 00000000000..9908f5c9738 --- /dev/null +++ b/third_party/forked/golang/go/types/api.go @@ -0,0 +1,376 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package types declares the data types and implements +// the algorithms for type-checking of Go packages. Use +// Config.Check to invoke the type checker for a package. +// Alternatively, create a new type checker with NewChecker +// and invoke it incrementally by calling Checker.Files. +// +// Type-checking consists of several interdependent phases: +// +// Name resolution maps each identifier (ast.Ident) in the program to the +// language object (Object) it denotes. +// Use Info.{Defs,Uses,Implicits} for the results of name resolution. +// +// Constant folding computes the exact constant value (constant.Value) +// for every expression (ast.Expr) that is a compile-time constant. +// Use Info.Types[expr].Value for the results of constant folding. +// +// Type inference computes the type (Type) of every expression (ast.Expr) +// and checks for compliance with the language specification. +// Use Info.Types[expr].Type for the results of type inference. +// +// For a tutorial, see https://golang.org/s/types-tutorial. +// +package types + +import ( + "bytes" + "fmt" + "go/ast" + "go/constant" + "go/token" +) + +// An Error describes a type-checking error; it implements the error interface. +// A "soft" error is an error that still permits a valid interpretation of a +// package (such as "unused variable"); "hard" errors may lead to unpredictable +// behavior if ignored. +type Error struct { + Fset *token.FileSet // file set for interpretation of Pos + Pos token.Pos // error position + Msg string // error message + Soft bool // if set, error is "soft" +} + +// Error returns an error string formatted as follows: +// filename:line:column: message +func (err Error) Error() string { + return fmt.Sprintf("%s: %s", err.Fset.Position(err.Pos), err.Msg) +} + +// An Importer resolves import paths to Packages. +// +// CAUTION: This interface does not support the import of locally +// vendored packages. See https://golang.org/s/go15vendor. +// If possible, external implementations should implement ImporterFrom. +type Importer interface { + // Import returns the imported package for the given import path. + // The semantics is like for ImporterFrom.ImportFrom except that + // dir and mode are ignored (since they are not present). + Import(path string) (*Package, error) +} + +// ImportMode is reserved for future use. +type ImportMode int + +// An ImporterFrom resolves import paths to packages; it +// supports vendoring per https://golang.org/s/go15vendor. +// Use go/importer to obtain an ImporterFrom implementation. +type ImporterFrom interface { + // Importer is present for backward-compatibility. Calling + // Import(path) is the same as calling ImportFrom(path, "", 0); + // i.e., locally vendored packages may not be found. + // The types package does not call Import if an ImporterFrom + // is present. + Importer + + // ImportFrom returns the imported package for the given import + // path when imported by a package file located in dir. + // If the import failed, besides returning an error, ImportFrom + // is encouraged to cache and return a package anyway, if one + // was created. This will reduce package inconsistencies and + // follow-on type checker errors due to the missing package. + // The mode value must be 0; it is reserved for future use. + // Two calls to ImportFrom with the same path and dir must + // return the same package. + ImportFrom(path, dir string, mode ImportMode) (*Package, error) +} + +// A Config specifies the configuration for type checking. +// The zero value for Config is a ready-to-use default configuration. +type Config struct { + // If IgnoreFuncBodies is set, function bodies are not + // type-checked. + IgnoreFuncBodies bool + + // If FakeImportC is set, `import "C"` (for packages requiring Cgo) + // declares an empty "C" package and errors are omitted for qualified + // identifiers referring to package C (which won't find an object). + // This feature is intended for the standard library cmd/api tool. + // + // Caution: Effects may be unpredictable due to follow-on errors. + // Do not use casually! + FakeImportC bool + + // If Error != nil, it is called with each error found + // during type checking; err has dynamic type Error. + // Secondary errors (for instance, to enumerate all types + // involved in an invalid recursive type declaration) have + // error strings that start with a '\t' character. + // If Error == nil, type-checking stops with the first + // error found. + Error func(err error) + + // An importer is used to import packages referred to from + // import declarations. + // If the installed importer implements ImporterFrom, the type + // checker calls ImportFrom instead of Import. + // The type checker reports an error if an importer is needed + // but none was installed. + Importer Importer + + // If Sizes != nil, it provides the sizing functions for package unsafe. + // Otherwise SizesFor("gc", "amd64") is used instead. + Sizes Sizes + + // If DisableUnusedImportCheck is set, packages are not checked + // for unused imports. + DisableUnusedImportCheck bool +} + +// Info holds result type information for a type-checked package. +// Only the information for which a map is provided is collected. +// If the package has type errors, the collected information may +// be incomplete. +type Info struct { + // Types maps expressions to their types, and for constant + // expressions, also their values. Invalid expressions are + // omitted. + // + // For (possibly parenthesized) identifiers denoting built-in + // functions, the recorded signatures are call-site specific: + // if the call result is not a constant, the recorded type is + // an argument-specific signature. Otherwise, the recorded type + // is invalid. + // + // The Types map does not record the type of every identifier, + // only those that appear where an arbitrary expression is + // permitted. For instance, the identifier f in a selector + // expression x.f is found only in the Selections map, the + // identifier z in a variable declaration 'var z int' is found + // only in the Defs map, and identifiers denoting packages in + // qualified identifiers are collected in the Uses map. + Types map[ast.Expr]TypeAndValue + + // Defs maps identifiers to the objects they define (including + // package names, dots "." of dot-imports, and blank "_" identifiers). + // For identifiers that do not denote objects (e.g., the package name + // in package clauses, or symbolic variables t in t := x.(type) of + // type switch headers), the corresponding objects are nil. + // + // For an anonymous field, Defs returns the field *Var it defines. + // + // Invariant: Defs[id] == nil || Defs[id].Pos() == id.Pos() + Defs map[*ast.Ident]Object + + // Uses maps identifiers to the objects they denote. + // + // For an anonymous field, Uses returns the *TypeName it denotes. + // + // Invariant: Uses[id].Pos() != id.Pos() + Uses map[*ast.Ident]Object + + // Implicits maps nodes to their implicitly declared objects, if any. + // The following node and object types may appear: + // + // node declared object + // + // *ast.ImportSpec *PkgName for imports without renames + // *ast.CaseClause type-specific *Var for each type switch case clause (incl. default) + // *ast.Field anonymous parameter *Var + // + Implicits map[ast.Node]Object + + // Selections maps selector expressions (excluding qualified identifiers) + // to their corresponding selections. + Selections map[*ast.SelectorExpr]*Selection + + // Scopes maps ast.Nodes to the scopes they define. Package scopes are not + // associated with a specific node but with all files belonging to a package. + // Thus, the package scope can be found in the type-checked Package object. + // Scopes nest, with the Universe scope being the outermost scope, enclosing + // the package scope, which contains (one or more) files scopes, which enclose + // function scopes which in turn enclose statement and function literal scopes. + // Note that even though package-level functions are declared in the package + // scope, the function scopes are embedded in the file scope of the file + // containing the function declaration. + // + // The following node types may appear in Scopes: + // + // *ast.File + // *ast.FuncType + // *ast.BlockStmt + // *ast.IfStmt + // *ast.SwitchStmt + // *ast.TypeSwitchStmt + // *ast.CaseClause + // *ast.CommClause + // *ast.ForStmt + // *ast.RangeStmt + // + Scopes map[ast.Node]*Scope + + // InitOrder is the list of package-level initializers in the order in which + // they must be executed. Initializers referring to variables related by an + // initialization dependency appear in topological order, the others appear + // in source order. Variables without an initialization expression do not + // appear in this list. + InitOrder []*Initializer +} + +// TypeOf returns the type of expression e, or nil if not found. +// Precondition: the Types, Uses and Defs maps are populated. +// +func (info *Info) TypeOf(e ast.Expr) Type { + if t, ok := info.Types[e]; ok { + return t.Type + } + if id, _ := e.(*ast.Ident); id != nil { + if obj := info.ObjectOf(id); obj != nil { + return obj.Type() + } + } + return nil +} + +// ObjectOf returns the object denoted by the specified id, +// or nil if not found. +// +// If id is an anonymous struct field, ObjectOf returns the field (*Var) +// it uses, not the type (*TypeName) it defines. +// +// Precondition: the Uses and Defs maps are populated. +// +func (info *Info) ObjectOf(id *ast.Ident) Object { + if obj := info.Defs[id]; obj != nil { + return obj + } + return info.Uses[id] +} + +// TypeAndValue reports the type and value (for constants) +// of the corresponding expression. +type TypeAndValue struct { + mode operandMode + Type Type + Value constant.Value +} + +// TODO(gri) Consider eliminating the IsVoid predicate. Instead, report +// "void" values as regular values but with the empty tuple type. + +// IsVoid reports whether the corresponding expression +// is a function call without results. +func (tv TypeAndValue) IsVoid() bool { + return tv.mode == novalue +} + +// IsType reports whether the corresponding expression specifies a type. +func (tv TypeAndValue) IsType() bool { + return tv.mode == typexpr +} + +// IsBuiltin reports whether the corresponding expression denotes +// a (possibly parenthesized) built-in function. +func (tv TypeAndValue) IsBuiltin() bool { + return tv.mode == builtin +} + +// IsValue reports whether the corresponding expression is a value. +// Builtins are not considered values. Constant values have a non- +// nil Value. +func (tv TypeAndValue) IsValue() bool { + switch tv.mode { + case constant_, variable, mapindex, value, commaok: + return true + } + return false +} + +// IsNil reports whether the corresponding expression denotes the +// predeclared value nil. +func (tv TypeAndValue) IsNil() bool { + return tv.mode == value && tv.Type == Typ[UntypedNil] +} + +// Addressable reports whether the corresponding expression +// is addressable (https://golang.org/ref/spec#Address_operators). +func (tv TypeAndValue) Addressable() bool { + return tv.mode == variable +} + +// Assignable reports whether the corresponding expression +// is assignable to (provided a value of the right type). +func (tv TypeAndValue) Assignable() bool { + return tv.mode == variable || tv.mode == mapindex +} + +// HasOk reports whether the corresponding expression may be +// used on the lhs of a comma-ok assignment. +func (tv TypeAndValue) HasOk() bool { + return tv.mode == commaok || tv.mode == mapindex +} + +// An Initializer describes a package-level variable, or a list of variables in case +// of a multi-valued initialization expression, and the corresponding initialization +// expression. +type Initializer struct { + Lhs []*Var // var Lhs = Rhs + Rhs ast.Expr +} + +func (init *Initializer) String() string { + var buf bytes.Buffer + for i, lhs := range init.Lhs { + if i > 0 { + buf.WriteString(", ") + } + buf.WriteString(lhs.Name()) + } + buf.WriteString(" = ") + WriteExpr(&buf, init.Rhs) + return buf.String() +} + +// Check type-checks a package and returns the resulting package object and +// the first error if any. Additionally, if info != nil, Check populates each +// of the non-nil maps in the Info struct. +// +// The package is marked as complete if no errors occurred, otherwise it is +// incomplete. See Config.Error for controlling behavior in the presence of +// errors. +// +// The package is specified by a list of *ast.Files and corresponding +// file set, and the package path the package is identified with. +// The clean path must not be empty or dot ("."). +func (conf *Config) Check(path string, fset *token.FileSet, files []*ast.File, info *Info) (*Package, error) { + pkg := NewPackage(path, "") + return pkg, NewChecker(conf, fset, pkg, info).Files(files) +} + +// AssertableTo reports whether a value of type V can be asserted to have type T. +func AssertableTo(V *Interface, T Type) bool { + m, _ := assertableTo(V, T) + return m == nil +} + +// AssignableTo reports whether a value of type V is assignable to a variable of type T. +func AssignableTo(V, T Type) bool { + x := operand{mode: value, typ: V} + return x.assignableTo(nil, T, nil) // config not needed for non-constant x +} + +// ConvertibleTo reports whether a value of type V is convertible to a value of type T. +func ConvertibleTo(V, T Type) bool { + x := operand{mode: value, typ: V} + return x.convertibleTo(nil, T) // config not needed for non-constant x +} + +// Implements reports whether type V implements interface T. +func Implements(V Type, T *Interface) bool { + f, _ := MissingMethod(V, T, true) + return f == nil +} diff --git a/third_party/forked/golang/go/types/assignments.go b/third_party/forked/golang/go/types/assignments.go new file mode 100644 index 00000000000..98c9e121b05 --- /dev/null +++ b/third_party/forked/golang/go/types/assignments.go @@ -0,0 +1,335 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements initialization and assignment checks. + +package types + +import ( + "go/ast" + "go/token" +) + +// assignment reports whether x can be assigned to a variable of type T, +// if necessary by attempting to convert untyped values to the appropriate +// type. context describes the context in which the assignment takes place. +// Use T == nil to indicate assignment to an untyped blank identifier. +// x.mode is set to invalid if the assignment failed. +func (check *Checker) assignment(x *operand, T Type, context string) { + check.singleValue(x) + + switch x.mode { + case invalid: + return // error reported before + case constant_, variable, mapindex, value, commaok: + // ok + default: + unreachable() + } + + if isUntyped(x.typ) { + target := T + // spec: "If an untyped constant is assigned to a variable of interface + // type or the blank identifier, the constant is first converted to type + // bool, rune, int, float64, complex128 or string respectively, depending + // on whether the value is a boolean, rune, integer, floating-point, complex, + // or string constant." + if T == nil || IsInterface(T) { + if T == nil && x.typ == Typ[UntypedNil] { + check.errorf(x.pos(), "use of untyped nil in %s", context) + x.mode = invalid + return + } + target = Default(x.typ) + } + check.convertUntyped(x, target) + if x.mode == invalid { + return + } + } + // x.typ is typed + + // spec: "If a left-hand side is the blank identifier, any typed or + // non-constant value except for the predeclared identifier nil may + // be assigned to it." + if T == nil { + return + } + + if reason := ""; !x.assignableTo(check.conf, T, &reason) { + if reason != "" { + check.errorf(x.pos(), "cannot use %s as %s value in %s: %s", x, T, context, reason) + } else { + check.errorf(x.pos(), "cannot use %s as %s value in %s", x, T, context) + } + x.mode = invalid + } +} + +func (check *Checker) initConst(lhs *Const, x *operand) { + if x.mode == invalid || x.typ == Typ[Invalid] || lhs.typ == Typ[Invalid] { + if lhs.typ == nil { + lhs.typ = Typ[Invalid] + } + return + } + + // rhs must be a constant + if x.mode != constant_ { + check.errorf(x.pos(), "%s is not constant", x) + if lhs.typ == nil { + lhs.typ = Typ[Invalid] + } + return + } + assert(isConstType(x.typ)) + + // If the lhs doesn't have a type yet, use the type of x. + if lhs.typ == nil { + lhs.typ = x.typ + } + + check.assignment(x, lhs.typ, "constant declaration") + if x.mode == invalid { + return + } + + lhs.val = x.val +} + +func (check *Checker) initVar(lhs *Var, x *operand, context string) Type { + if x.mode == invalid || x.typ == Typ[Invalid] || lhs.typ == Typ[Invalid] { + if lhs.typ == nil { + lhs.typ = Typ[Invalid] + } + return nil + } + + // If the lhs doesn't have a type yet, use the type of x. + if lhs.typ == nil { + typ := x.typ + if isUntyped(typ) { + // convert untyped types to default types + if typ == Typ[UntypedNil] { + check.errorf(x.pos(), "use of untyped nil in %s", context) + lhs.typ = Typ[Invalid] + return nil + } + typ = Default(typ) + } + lhs.typ = typ + } + + check.assignment(x, lhs.typ, context) + if x.mode == invalid { + return nil + } + + return x.typ +} + +func (check *Checker) assignVar(lhs ast.Expr, x *operand) Type { + if x.mode == invalid || x.typ == Typ[Invalid] { + return nil + } + + // Determine if the lhs is a (possibly parenthesized) identifier. + ident, _ := unparen(lhs).(*ast.Ident) + + // Don't evaluate lhs if it is the blank identifier. + if ident != nil && ident.Name == "_" { + check.recordDef(ident, nil) + check.assignment(x, nil, "assignment to _ identifier") + if x.mode == invalid { + return nil + } + return x.typ + } + + // If the lhs is an identifier denoting a variable v, this assignment + // is not a 'use' of v. Remember current value of v.used and restore + // after evaluating the lhs via check.expr. + var v *Var + var v_used bool + if ident != nil { + if _, obj := check.scope.LookupParent(ident.Name, token.NoPos); obj != nil { + // It's ok to mark non-local variables, but ignore variables + // from other packages to avoid potential race conditions with + // dot-imported variables. + if w, _ := obj.(*Var); w != nil && w.pkg == check.pkg { + v = w + v_used = v.used + } + } + } + + var z operand + check.expr(&z, lhs) + if v != nil { + v.used = v_used // restore v.used + } + + if z.mode == invalid || z.typ == Typ[Invalid] { + return nil + } + + // spec: "Each left-hand side operand must be addressable, a map index + // expression, or the blank identifier. Operands may be parenthesized." + switch z.mode { + case invalid: + return nil + case variable, mapindex: + // ok + default: + if sel, ok := z.expr.(*ast.SelectorExpr); ok { + var op operand + check.expr(&op, sel.X) + if op.mode == mapindex { + check.errorf(z.pos(), "cannot assign to struct field %s in map", ExprString(z.expr)) + return nil + } + } + check.errorf(z.pos(), "cannot assign to %s", &z) + return nil + } + + check.assignment(x, z.typ, "assignment") + if x.mode == invalid { + return nil + } + + return x.typ +} + +// If returnPos is valid, initVars is called to type-check the assignment of +// return expressions, and returnPos is the position of the return statement. +func (check *Checker) initVars(lhs []*Var, rhs []ast.Expr, returnPos token.Pos) { + l := len(lhs) + get, r, commaOk := unpack(func(x *operand, i int) { check.multiExpr(x, rhs[i]) }, len(rhs), l == 2 && !returnPos.IsValid()) + if get == nil || l != r { + // invalidate lhs and use rhs + for _, obj := range lhs { + if obj.typ == nil { + obj.typ = Typ[Invalid] + } + } + if get == nil { + return // error reported by unpack + } + check.useGetter(get, r) + if returnPos.IsValid() { + check.errorf(returnPos, "wrong number of return values (want %d, got %d)", l, r) + return + } + check.errorf(rhs[0].Pos(), "cannot initialize %d variables with %d values", l, r) + return + } + + context := "assignment" + if returnPos.IsValid() { + context = "return statement" + } + + var x operand + if commaOk { + var a [2]Type + for i := range a { + get(&x, i) + a[i] = check.initVar(lhs[i], &x, context) + } + check.recordCommaOkTypes(rhs[0], a) + return + } + + for i, lhs := range lhs { + get(&x, i) + check.initVar(lhs, &x, context) + } +} + +func (check *Checker) assignVars(lhs, rhs []ast.Expr) { + l := len(lhs) + get, r, commaOk := unpack(func(x *operand, i int) { check.multiExpr(x, rhs[i]) }, len(rhs), l == 2) + if get == nil { + check.useLHS(lhs...) + return // error reported by unpack + } + if l != r { + check.useGetter(get, r) + check.errorf(rhs[0].Pos(), "cannot assign %d values to %d variables", r, l) + return + } + + var x operand + if commaOk { + var a [2]Type + for i := range a { + get(&x, i) + a[i] = check.assignVar(lhs[i], &x) + } + check.recordCommaOkTypes(rhs[0], a) + return + } + + for i, lhs := range lhs { + get(&x, i) + check.assignVar(lhs, &x) + } +} + +func (check *Checker) shortVarDecl(pos token.Pos, lhs, rhs []ast.Expr) { + scope := check.scope + + // collect lhs variables + var newVars []*Var + var lhsVars = make([]*Var, len(lhs)) + for i, lhs := range lhs { + var obj *Var + if ident, _ := lhs.(*ast.Ident); ident != nil { + // Use the correct obj if the ident is redeclared. The + // variable's scope starts after the declaration; so we + // must use Scope.Lookup here and call Scope.Insert + // (via check.declare) later. + name := ident.Name + if alt := scope.Lookup(name); alt != nil { + // redeclared object must be a variable + if alt, _ := alt.(*Var); alt != nil { + obj = alt + } else { + check.errorf(lhs.Pos(), "cannot assign to %s", lhs) + } + check.recordUse(ident, alt) + } else { + // declare new variable, possibly a blank (_) variable + obj = NewVar(ident.Pos(), check.pkg, name, nil) + if name != "_" { + newVars = append(newVars, obj) + } + check.recordDef(ident, obj) + } + } else { + check.errorf(lhs.Pos(), "cannot declare %s", lhs) + } + if obj == nil { + obj = NewVar(lhs.Pos(), check.pkg, "_", nil) // dummy variable + } + lhsVars[i] = obj + } + + check.initVars(lhsVars, rhs, token.NoPos) + + // declare new variables + if len(newVars) > 0 { + // spec: "The scope of a constant or variable identifier declared inside + // a function begins at the end of the ConstSpec or VarSpec (ShortVarDecl + // for short variable declarations) and ends at the end of the innermost + // containing block." + scopePos := rhs[len(rhs)-1].End() + for _, obj := range newVars { + check.declare(scope, nil, obj, scopePos) // recordObject already called + } + } else { + check.softErrorf(pos, "no new variables on left side of :=") + } +} diff --git a/third_party/forked/golang/go/types/builtins.go b/third_party/forked/golang/go/types/builtins.go new file mode 100644 index 00000000000..87f80630ac1 --- /dev/null +++ b/third_party/forked/golang/go/types/builtins.go @@ -0,0 +1,670 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements typechecking of builtin function calls. + +package types + +import ( + "go/ast" + "go/constant" + "go/token" +) + +// builtin type-checks a call to the built-in specified by id and +// returns true if the call is valid, with *x holding the result; +// but x.expr is not set. If the call is invalid, the result is +// false, and *x is undefined. +// +func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ bool) { + // append is the only built-in that permits the use of ... for the last argument + bin := predeclaredFuncs[id] + if call.Ellipsis.IsValid() && id != _Append { + check.invalidOp(call.Ellipsis, "invalid use of ... with built-in %s", bin.name) + check.use(call.Args...) + return + } + + // For len(x) and cap(x) we need to know if x contains any function calls or + // receive operations. Save/restore current setting and set hasCallOrRecv to + // false for the evaluation of x so that we can check it afterwards. + // Note: We must do this _before_ calling unpack because unpack evaluates the + // first argument before we even call arg(x, 0)! + if id == _Len || id == _Cap { + defer func(b bool) { + check.hasCallOrRecv = b + }(check.hasCallOrRecv) + check.hasCallOrRecv = false + } + + // determine actual arguments + var arg getter + nargs := len(call.Args) + switch id { + default: + // make argument getter + arg, nargs, _ = unpack(func(x *operand, i int) { check.multiExpr(x, call.Args[i]) }, nargs, false) + if arg == nil { + return + } + // evaluate first argument, if present + if nargs > 0 { + arg(x, 0) + if x.mode == invalid { + return + } + } + case _Make, _New, _Offsetof, _Trace: + // arguments require special handling + } + + // check argument count + { + msg := "" + if nargs < bin.nargs { + msg = "not enough" + } else if !bin.variadic && nargs > bin.nargs { + msg = "too many" + } + if msg != "" { + check.invalidOp(call.Rparen, "%s arguments for %s (expected %d, found %d)", msg, call, bin.nargs, nargs) + return + } + } + + switch id { + case _Append: + // append(s S, x ...T) S, where T is the element type of S + // spec: "The variadic function append appends zero or more values x to s of type + // S, which must be a slice type, and returns the resulting slice, also of type S. + // The values x are passed to a parameter of type ...T where T is the element type + // of S and the respective parameter passing rules apply." + S := x.typ + var T Type + if s, _ := S.Underlying().(*Slice); s != nil { + T = s.elem + } else { + check.invalidArg(x.pos(), "%s is not a slice", x) + return + } + + // remember arguments that have been evaluated already + alist := []operand{*x} + + // spec: "As a special case, append also accepts a first argument assignable + // to type []byte with a second argument of string type followed by ... . + // This form appends the bytes of the string. + if nargs == 2 && call.Ellipsis.IsValid() && x.assignableTo(check.conf, NewSlice(universeByte), nil) { + arg(x, 1) + if x.mode == invalid { + return + } + if isString(x.typ) { + if check.Types != nil { + sig := makeSig(S, S, x.typ) + sig.variadic = true + check.recordBuiltinType(call.Fun, sig) + } + x.mode = value + x.typ = S + break + } + alist = append(alist, *x) + // fallthrough + } + + // check general case by creating custom signature + sig := makeSig(S, S, NewSlice(T)) // []T required for variadic signature + sig.variadic = true + check.arguments(x, call, sig, func(x *operand, i int) { + // only evaluate arguments that have not been evaluated before + if i < len(alist) { + *x = alist[i] + return + } + arg(x, i) + }, nargs) + // ok to continue even if check.arguments reported errors + + x.mode = value + x.typ = S + if check.Types != nil { + check.recordBuiltinType(call.Fun, sig) + } + + case _Cap, _Len: + // cap(x) + // len(x) + mode := invalid + var typ Type + var val constant.Value + switch typ = implicitArrayDeref(x.typ.Underlying()); t := typ.(type) { + case *Basic: + if isString(t) && id == _Len { + if x.mode == constant_ { + mode = constant_ + val = constant.MakeInt64(int64(len(constant.StringVal(x.val)))) + } else { + mode = value + } + } + + case *Array: + mode = value + // spec: "The expressions len(s) and cap(s) are constants + // if the type of s is an array or pointer to an array and + // the expression s does not contain channel receives or + // function calls; in this case s is not evaluated." + if !check.hasCallOrRecv { + mode = constant_ + if t.len >= 0 { + val = constant.MakeInt64(t.len) + } else { + val = constant.MakeUnknown() + } + } + + case *Slice, *Chan: + mode = value + + case *Map: + if id == _Len { + mode = value + } + } + + if mode == invalid { + check.invalidArg(x.pos(), "%s for %s", x, bin.name) + return + } + + x.mode = mode + x.typ = Typ[Int] + x.val = val + if check.Types != nil && mode != constant_ { + check.recordBuiltinType(call.Fun, makeSig(x.typ, typ)) + } + + case _Close: + // close(c) + c, _ := x.typ.Underlying().(*Chan) + if c == nil { + check.invalidArg(x.pos(), "%s is not a channel", x) + return + } + if c.dir == RecvOnly { + check.invalidArg(x.pos(), "%s must not be a receive-only channel", x) + return + } + + x.mode = novalue + if check.Types != nil { + check.recordBuiltinType(call.Fun, makeSig(nil, c)) + } + + case _Complex: + // complex(x, y floatT) complexT + var y operand + arg(&y, 1) + if y.mode == invalid { + return + } + + // convert or check untyped arguments + d := 0 + if isUntyped(x.typ) { + d |= 1 + } + if isUntyped(y.typ) { + d |= 2 + } + switch d { + case 0: + // x and y are typed => nothing to do + case 1: + // only x is untyped => convert to type of y + check.convertUntyped(x, y.typ) + case 2: + // only y is untyped => convert to type of x + check.convertUntyped(&y, x.typ) + case 3: + // x and y are untyped => + // 1) if both are constants, convert them to untyped + // floating-point numbers if possible, + // 2) if one of them is not constant (possible because + // it contains a shift that is yet untyped), convert + // both of them to float64 since they must have the + // same type to succeed (this will result in an error + // because shifts of floats are not permitted) + if x.mode == constant_ && y.mode == constant_ { + toFloat := func(x *operand) { + if isNumeric(x.typ) && constant.Sign(constant.Imag(x.val)) == 0 { + x.typ = Typ[UntypedFloat] + } + } + toFloat(x) + toFloat(&y) + } else { + check.convertUntyped(x, Typ[Float64]) + check.convertUntyped(&y, Typ[Float64]) + // x and y should be invalid now, but be conservative + // and check below + } + } + if x.mode == invalid || y.mode == invalid { + return + } + + // both argument types must be identical + if !Identical(x.typ, y.typ) { + check.invalidArg(x.pos(), "mismatched types %s and %s", x.typ, y.typ) + return + } + + // the argument types must be of floating-point type + if !isFloat(x.typ) { + check.invalidArg(x.pos(), "arguments have type %s, expected floating-point", x.typ) + return + } + + // if both arguments are constants, the result is a constant + if x.mode == constant_ && y.mode == constant_ { + x.val = constant.BinaryOp(constant.ToFloat(x.val), token.ADD, constant.MakeImag(constant.ToFloat(y.val))) + } else { + x.mode = value + } + + // determine result type + var res BasicKind + switch x.typ.Underlying().(*Basic).kind { + case Float32: + res = Complex64 + case Float64: + res = Complex128 + case UntypedFloat: + res = UntypedComplex + default: + unreachable() + } + resTyp := Typ[res] + + if check.Types != nil && x.mode != constant_ { + check.recordBuiltinType(call.Fun, makeSig(resTyp, x.typ, x.typ)) + } + + x.typ = resTyp + + case _Copy: + // copy(x, y []T) int + var dst Type + if t, _ := x.typ.Underlying().(*Slice); t != nil { + dst = t.elem + } + + var y operand + arg(&y, 1) + if y.mode == invalid { + return + } + var src Type + switch t := y.typ.Underlying().(type) { + case *Basic: + if isString(y.typ) { + src = universeByte + } + case *Slice: + src = t.elem + } + + if dst == nil || src == nil { + check.invalidArg(x.pos(), "copy expects slice arguments; found %s and %s", x, &y) + return + } + + if !Identical(dst, src) { + check.invalidArg(x.pos(), "arguments to copy %s and %s have different element types %s and %s", x, &y, dst, src) + return + } + + if check.Types != nil { + check.recordBuiltinType(call.Fun, makeSig(Typ[Int], x.typ, y.typ)) + } + x.mode = value + x.typ = Typ[Int] + + case _Delete: + // delete(m, k) + m, _ := x.typ.Underlying().(*Map) + if m == nil { + check.invalidArg(x.pos(), "%s is not a map", x) + return + } + arg(x, 1) // k + if x.mode == invalid { + return + } + + if !x.assignableTo(check.conf, m.key, nil) { + check.invalidArg(x.pos(), "%s is not assignable to %s", x, m.key) + return + } + + x.mode = novalue + if check.Types != nil { + check.recordBuiltinType(call.Fun, makeSig(nil, m, m.key)) + } + + case _Imag, _Real: + // imag(complexT) floatT + // real(complexT) floatT + + // convert or check untyped argument + if isUntyped(x.typ) { + if x.mode == constant_ { + // an untyped constant number can alway be considered + // as a complex constant + if isNumeric(x.typ) { + x.typ = Typ[UntypedComplex] + } + } else { + // an untyped non-constant argument may appear if + // it contains a (yet untyped non-constant) shift + // expression: convert it to complex128 which will + // result in an error (shift of complex value) + check.convertUntyped(x, Typ[Complex128]) + // x should be invalid now, but be conservative and check + if x.mode == invalid { + return + } + } + } + + // the argument must be of complex type + if !isComplex(x.typ) { + check.invalidArg(x.pos(), "argument has type %s, expected complex type", x.typ) + return + } + + // if the argument is a constant, the result is a constant + if x.mode == constant_ { + if id == _Real { + x.val = constant.Real(x.val) + } else { + x.val = constant.Imag(x.val) + } + } else { + x.mode = value + } + + // determine result type + var res BasicKind + switch x.typ.Underlying().(*Basic).kind { + case Complex64: + res = Float32 + case Complex128: + res = Float64 + case UntypedComplex: + res = UntypedFloat + default: + unreachable() + } + resTyp := Typ[res] + + if check.Types != nil && x.mode != constant_ { + check.recordBuiltinType(call.Fun, makeSig(resTyp, x.typ)) + } + + x.typ = resTyp + + case _Make: + // make(T, n) + // make(T, n, m) + // (no argument evaluated yet) + arg0 := call.Args[0] + T := check.typ(arg0) + if T == Typ[Invalid] { + return + } + + var min int // minimum number of arguments + switch T.Underlying().(type) { + case *Slice: + min = 2 + case *Map, *Chan: + min = 1 + default: + check.invalidArg(arg0.Pos(), "cannot make %s; type must be slice, map, or channel", arg0) + return + } + if nargs < min || min+1 < nargs { + check.errorf(call.Pos(), "%v expects %d or %d arguments; found %d", call, min, min+1, nargs) + return + } + var sizes []int64 // constant integer arguments, if any + for _, arg := range call.Args[1:] { + if s, ok := check.index(arg, -1); ok && s >= 0 { + sizes = append(sizes, s) + } + } + if len(sizes) == 2 && sizes[0] > sizes[1] { + check.invalidArg(call.Args[1].Pos(), "length and capacity swapped") + // safe to continue + } + x.mode = value + x.typ = T + if check.Types != nil { + params := [...]Type{T, Typ[Int], Typ[Int]} + check.recordBuiltinType(call.Fun, makeSig(x.typ, params[:1+len(sizes)]...)) + } + + case _New: + // new(T) + // (no argument evaluated yet) + T := check.typ(call.Args[0]) + if T == Typ[Invalid] { + return + } + + x.mode = value + x.typ = &Pointer{base: T} + if check.Types != nil { + check.recordBuiltinType(call.Fun, makeSig(x.typ, T)) + } + + case _Panic: + // panic(x) + check.assignment(x, &emptyInterface, "argument to panic") + if x.mode == invalid { + return + } + + x.mode = novalue + if check.Types != nil { + check.recordBuiltinType(call.Fun, makeSig(nil, &emptyInterface)) + } + + case _Print, _Println: + // print(x, y, ...) + // println(x, y, ...) + var params []Type + if nargs > 0 { + params = make([]Type, nargs) + for i := 0; i < nargs; i++ { + if i > 0 { + arg(x, i) // first argument already evaluated + } + check.assignment(x, nil, "argument to "+predeclaredFuncs[id].name) + if x.mode == invalid { + // TODO(gri) "use" all arguments? + return + } + params[i] = x.typ + } + } + + x.mode = novalue + if check.Types != nil { + check.recordBuiltinType(call.Fun, makeSig(nil, params...)) + } + + case _Recover: + // recover() interface{} + x.mode = value + x.typ = &emptyInterface + if check.Types != nil { + check.recordBuiltinType(call.Fun, makeSig(x.typ)) + } + + case _Alignof: + // unsafe.Alignof(x T) uintptr + check.assignment(x, nil, "argument to unsafe.Alignof") + if x.mode == invalid { + return + } + + x.mode = constant_ + x.val = constant.MakeInt64(check.conf.alignof(x.typ)) + x.typ = Typ[Uintptr] + // result is constant - no need to record signature + + case _Offsetof: + // unsafe.Offsetof(x T) uintptr, where x must be a selector + // (no argument evaluated yet) + arg0 := call.Args[0] + selx, _ := unparen(arg0).(*ast.SelectorExpr) + if selx == nil { + check.invalidArg(arg0.Pos(), "%s is not a selector expression", arg0) + check.use(arg0) + return + } + + check.expr(x, selx.X) + if x.mode == invalid { + return + } + + base := derefStructPtr(x.typ) + sel := selx.Sel.Name + obj, index, indirect := LookupFieldOrMethod(base, false, check.pkg, sel) + switch obj.(type) { + case nil: + check.invalidArg(x.pos(), "%s has no single field %s", base, sel) + return + case *Func: + // TODO(gri) Using derefStructPtr may result in methods being found + // that don't actually exist. An error either way, but the error + // message is confusing. See: https://play.golang.org/p/al75v23kUy , + // but go/types reports: "invalid argument: x.m is a method value". + check.invalidArg(arg0.Pos(), "%s is a method value", arg0) + return + } + if indirect { + check.invalidArg(x.pos(), "field %s is embedded via a pointer in %s", sel, base) + return + } + + // TODO(gri) Should we pass x.typ instead of base (and indirect report if derefStructPtr indirected)? + check.recordSelection(selx, FieldVal, base, obj, index, false) + + offs := check.conf.offsetof(base, index) + x.mode = constant_ + x.val = constant.MakeInt64(offs) + x.typ = Typ[Uintptr] + // result is constant - no need to record signature + + case _Sizeof: + // unsafe.Sizeof(x T) uintptr + check.assignment(x, nil, "argument to unsafe.Sizeof") + if x.mode == invalid { + return + } + + x.mode = constant_ + x.val = constant.MakeInt64(check.conf.sizeof(x.typ)) + x.typ = Typ[Uintptr] + // result is constant - no need to record signature + + case _Assert: + // assert(pred) causes a typechecker error if pred is false. + // The result of assert is the value of pred if there is no error. + // Note: assert is only available in self-test mode. + if x.mode != constant_ || !isBoolean(x.typ) { + check.invalidArg(x.pos(), "%s is not a boolean constant", x) + return + } + if x.val.Kind() != constant.Bool { + check.errorf(x.pos(), "internal error: value of %s should be a boolean constant", x) + return + } + if !constant.BoolVal(x.val) { + check.errorf(call.Pos(), "%v failed", call) + // compile-time assertion failure - safe to continue + } + // result is constant - no need to record signature + + case _Trace: + // trace(x, y, z, ...) dumps the positions, expressions, and + // values of its arguments. The result of trace is the value + // of the first argument. + // Note: trace is only available in self-test mode. + // (no argument evaluated yet) + if nargs == 0 { + check.dump("%s: trace() without arguments", call.Pos()) + x.mode = novalue + break + } + var t operand + x1 := x + for _, arg := range call.Args { + check.rawExpr(x1, arg, nil) // permit trace for types, e.g.: new(trace(T)) + check.dump("%s: %s", x1.pos(), x1) + x1 = &t // use incoming x only for first argument + } + // trace is only available in test mode - no need to record signature + + default: + unreachable() + } + + return true +} + +// makeSig makes a signature for the given argument and result types. +// Default types are used for untyped arguments, and res may be nil. +func makeSig(res Type, args ...Type) *Signature { + list := make([]*Var, len(args)) + for i, param := range args { + list[i] = NewVar(token.NoPos, nil, "", Default(param)) + } + params := NewTuple(list...) + var result *Tuple + if res != nil { + assert(!isUntyped(res)) + result = NewTuple(NewVar(token.NoPos, nil, "", res)) + } + return &Signature{params: params, results: result} +} + +// implicitArrayDeref returns A if typ is of the form *A and A is an array; +// otherwise it returns typ. +// +func implicitArrayDeref(typ Type) Type { + if p, ok := typ.(*Pointer); ok { + if a, ok := p.base.Underlying().(*Array); ok { + return a + } + } + return typ +} + +// unparen returns e with any enclosing parentheses stripped. +func unparen(e ast.Expr) ast.Expr { + for { + p, ok := e.(*ast.ParenExpr) + if !ok { + return e + } + e = p.X + } +} diff --git a/third_party/forked/golang/go/types/call.go b/third_party/forked/golang/go/types/call.go new file mode 100644 index 00000000000..8fe65e41d5f --- /dev/null +++ b/third_party/forked/golang/go/types/call.go @@ -0,0 +1,478 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements typechecking of call and selector expressions. + +package types + +import ( + "go/ast" + "go/token" +) + +func (check *Checker) call(x *operand, e *ast.CallExpr) exprKind { + check.exprOrType(x, e.Fun) + + switch x.mode { + case invalid: + check.use(e.Args...) + x.mode = invalid + x.expr = e + return statement + + case typexpr: + // conversion + T := x.typ + x.mode = invalid + switch n := len(e.Args); n { + case 0: + check.errorf(e.Rparen, "missing argument in conversion to %s", T) + case 1: + check.expr(x, e.Args[0]) + if x.mode != invalid { + check.conversion(x, T) + } + default: + check.errorf(e.Args[n-1].Pos(), "too many arguments in conversion to %s", T) + } + x.expr = e + return conversion + + case builtin: + id := x.id + if !check.builtin(x, e, id) { + x.mode = invalid + } + x.expr = e + // a non-constant result implies a function call + if x.mode != invalid && x.mode != constant_ { + check.hasCallOrRecv = true + } + return predeclaredFuncs[id].kind + + default: + // function/method call + sig, _ := x.typ.Underlying().(*Signature) + if sig == nil { + check.invalidOp(x.pos(), "cannot call non-function %s", x) + x.mode = invalid + x.expr = e + return statement + } + + arg, n, _ := unpack(func(x *operand, i int) { check.multiExpr(x, e.Args[i]) }, len(e.Args), false) + if arg != nil { + check.arguments(x, e, sig, arg, n) + } else { + x.mode = invalid + } + + // determine result + switch sig.results.Len() { + case 0: + x.mode = novalue + case 1: + x.mode = value + x.typ = sig.results.vars[0].typ // unpack tuple + default: + x.mode = value + x.typ = sig.results + } + + x.expr = e + check.hasCallOrRecv = true + + return statement + } +} + +// use type-checks each argument. +// Useful to make sure expressions are evaluated +// (and variables are "used") in the presence of other errors. +// The arguments may be nil. +func (check *Checker) use(arg ...ast.Expr) { + var x operand + for _, e := range arg { + // The nil check below is necessary since certain AST fields + // may legally be nil (e.g., the ast.SliceExpr.High field). + if e != nil { + check.rawExpr(&x, e, nil) + } + } +} + +// useLHS is like use, but doesn't "use" top-level identifiers. +// It should be called instead of use if the arguments are +// expressions on the lhs of an assignment. +// The arguments must not be nil. +func (check *Checker) useLHS(arg ...ast.Expr) { + var x operand + for _, e := range arg { + // If the lhs is an identifier denoting a variable v, this assignment + // is not a 'use' of v. Remember current value of v.used and restore + // after evaluating the lhs via check.rawExpr. + var v *Var + var v_used bool + if ident, _ := unparen(e).(*ast.Ident); ident != nil { + // never type-check the blank name on the lhs + if ident.Name == "_" { + continue + } + if _, obj := check.scope.LookupParent(ident.Name, token.NoPos); obj != nil { + // It's ok to mark non-local variables, but ignore variables + // from other packages to avoid potential race conditions with + // dot-imported variables. + if w, _ := obj.(*Var); w != nil && w.pkg == check.pkg { + v = w + v_used = v.used + } + } + } + check.rawExpr(&x, e, nil) + if v != nil { + v.used = v_used // restore v.used + } + } +} + +// useGetter is like use, but takes a getter instead of a list of expressions. +// It should be called instead of use if a getter is present to avoid repeated +// evaluation of the first argument (since the getter was likely obtained via +// unpack, which may have evaluated the first argument already). +func (check *Checker) useGetter(get getter, n int) { + var x operand + for i := 0; i < n; i++ { + get(&x, i) + } +} + +// A getter sets x as the i'th operand, where 0 <= i < n and n is the total +// number of operands (context-specific, and maintained elsewhere). A getter +// type-checks the i'th operand; the details of the actual check are getter- +// specific. +type getter func(x *operand, i int) + +// unpack takes a getter get and a number of operands n. If n == 1, unpack +// calls the incoming getter for the first operand. If that operand is +// invalid, unpack returns (nil, 0, false). Otherwise, if that operand is a +// function call, or a comma-ok expression and allowCommaOk is set, the result +// is a new getter and operand count providing access to the function results, +// or comma-ok values, respectively. The third result value reports if it +// is indeed the comma-ok case. In all other cases, the incoming getter and +// operand count are returned unchanged, and the third result value is false. +// +// In other words, if there's exactly one operand that - after type-checking +// by calling get - stands for multiple operands, the resulting getter provides +// access to those operands instead. +// +// If the returned getter is called at most once for a given operand index i +// (including i == 0), that operand is guaranteed to cause only one call of +// the incoming getter with that i. +// +func unpack(get getter, n int, allowCommaOk bool) (getter, int, bool) { + if n != 1 { + // zero or multiple values + return get, n, false + } + // possibly result of an n-valued function call or comma,ok value + var x0 operand + get(&x0, 0) + if x0.mode == invalid { + return nil, 0, false + } + + if t, ok := x0.typ.(*Tuple); ok { + // result of an n-valued function call + return func(x *operand, i int) { + x.mode = value + x.expr = x0.expr + x.typ = t.At(i).typ + }, t.Len(), false + } + + if x0.mode == mapindex || x0.mode == commaok { + // comma-ok value + if allowCommaOk { + a := [2]Type{x0.typ, Typ[UntypedBool]} + return func(x *operand, i int) { + x.mode = value + x.expr = x0.expr + x.typ = a[i] + }, 2, true + } + x0.mode = value + } + + // single value + return func(x *operand, i int) { + if i != 0 { + unreachable() + } + *x = x0 + }, 1, false +} + +// arguments checks argument passing for the call with the given signature. +// The arg function provides the operand for the i'th argument. +func (check *Checker) arguments(x *operand, call *ast.CallExpr, sig *Signature, arg getter, n int) { + if call.Ellipsis.IsValid() { + // last argument is of the form x... + if !sig.variadic { + check.errorf(call.Ellipsis, "cannot use ... in call to non-variadic %s", call.Fun) + check.useGetter(arg, n) + return + } + if len(call.Args) == 1 && n > 1 { + // f()... is not permitted if f() is multi-valued + check.errorf(call.Ellipsis, "cannot use ... with %d-valued %s", n, call.Args[0]) + check.useGetter(arg, n) + return + } + } + + // evaluate arguments + for i := 0; i < n; i++ { + arg(x, i) + if x.mode != invalid { + var ellipsis token.Pos + if i == n-1 && call.Ellipsis.IsValid() { + ellipsis = call.Ellipsis + } + check.argument(call.Fun, sig, i, x, ellipsis) + } + } + + // check argument count + if sig.variadic { + // a variadic function accepts an "empty" + // last argument: count one extra + n++ + } + if n < sig.params.Len() { + check.errorf(call.Rparen, "too few arguments in call to %s", call.Fun) + // ok to continue + } +} + +// argument checks passing of argument x to the i'th parameter of the given signature. +// If ellipsis is valid, the argument is followed by ... at that position in the call. +func (check *Checker) argument(fun ast.Expr, sig *Signature, i int, x *operand, ellipsis token.Pos) { + check.singleValue(x) + if x.mode == invalid { + return + } + + n := sig.params.Len() + + // determine parameter type + var typ Type + switch { + case i < n: + typ = sig.params.vars[i].typ + case sig.variadic: + typ = sig.params.vars[n-1].typ + if debug { + if _, ok := typ.(*Slice); !ok { + check.dump("%s: expected unnamed slice type, got %s", sig.params.vars[n-1].Pos(), typ) + } + } + default: + check.errorf(x.pos(), "too many arguments") + return + } + + if ellipsis.IsValid() { + // argument is of the form x... and x is single-valued + if i != n-1 { + check.errorf(ellipsis, "can only use ... with matching parameter") + return + } + if _, ok := x.typ.Underlying().(*Slice); !ok && x.typ != Typ[UntypedNil] { // see issue #18268 + check.errorf(x.pos(), "cannot use %s as parameter of type %s", x, typ) + return + } + } else if sig.variadic && i >= n-1 { + // use the variadic parameter slice's element type + typ = typ.(*Slice).elem + } + + check.assignment(x, typ, check.sprintf("argument to %s", fun)) +} + +func (check *Checker) selector(x *operand, e *ast.SelectorExpr) { + // these must be declared before the "goto Error" statements + var ( + obj Object + index []int + indirect bool + ) + + sel := e.Sel.Name + // If the identifier refers to a package, handle everything here + // so we don't need a "package" mode for operands: package names + // can only appear in qualified identifiers which are mapped to + // selector expressions. + if ident, ok := e.X.(*ast.Ident); ok { + _, obj := check.scope.LookupParent(ident.Name, check.pos) + if pname, _ := obj.(*PkgName); pname != nil { + assert(pname.pkg == check.pkg) + check.recordUse(ident, pname) + pname.used = true + pkg := pname.imported + exp := pkg.scope.Lookup(sel) + if exp == nil { + if !pkg.fake { + check.errorf(e.Pos(), "%s not declared by package %s", sel, pkg.name) + } + goto Error + } + if !exp.Exported() { + check.errorf(e.Pos(), "%s not exported by package %s", sel, pkg.name) + // ok to continue + } + check.recordUse(e.Sel, exp) + + // Simplified version of the code for *ast.Idents: + // - imported objects are always fully initialized + switch exp := exp.(type) { + case *Const: + assert(exp.Val() != nil) + x.mode = constant_ + x.typ = exp.typ + x.val = exp.val + case *TypeName: + x.mode = typexpr + x.typ = exp.typ + case *Var: + x.mode = variable + x.typ = exp.typ + case *Func: + x.mode = value + x.typ = exp.typ + case *Builtin: + x.mode = builtin + x.typ = exp.typ + x.id = exp.id + default: + check.dump("unexpected object %v", exp) + unreachable() + } + x.expr = e + return + } + } + + check.exprOrType(x, e.X) + if x.mode == invalid { + goto Error + } + + obj, index, indirect = LookupFieldOrMethod(x.typ, x.mode == variable, check.pkg, sel) + if obj == nil { + switch { + case index != nil: + // TODO(gri) should provide actual type where the conflict happens + check.invalidOp(e.Pos(), "ambiguous selector %s", sel) + case indirect: + check.invalidOp(e.Pos(), "%s is not in method set of %s", sel, x.typ) + default: + check.invalidOp(e.Pos(), "%s has no field or method %s", x, sel) + } + goto Error + } + + if x.mode == typexpr { + // method expression + m, _ := obj.(*Func) + if m == nil { + check.invalidOp(e.Pos(), "%s has no method %s", x, sel) + goto Error + } + + check.recordSelection(e, MethodExpr, x.typ, m, index, indirect) + + // the receiver type becomes the type of the first function + // argument of the method expression's function type + var params []*Var + sig := m.typ.(*Signature) + if sig.params != nil { + params = sig.params.vars + } + x.mode = value + x.typ = &Signature{ + params: NewTuple(append([]*Var{NewVar(token.NoPos, check.pkg, "", x.typ)}, params...)...), + results: sig.results, + variadic: sig.variadic, + } + + check.addDeclDep(m) + + } else { + // regular selector + switch obj := obj.(type) { + case *Var: + check.recordSelection(e, FieldVal, x.typ, obj, index, indirect) + if x.mode == variable || indirect { + x.mode = variable + } else { + x.mode = value + } + x.typ = obj.typ + + case *Func: + // TODO(gri) If we needed to take into account the receiver's + // addressability, should we report the type &(x.typ) instead? + check.recordSelection(e, MethodVal, x.typ, obj, index, indirect) + + if debug { + // Verify that LookupFieldOrMethod and MethodSet.Lookup agree. + typ := x.typ + if x.mode == variable { + // If typ is not an (unnamed) pointer or an interface, + // use *typ instead, because the method set of *typ + // includes the methods of typ. + // Variables are addressable, so we can always take their + // address. + if _, ok := typ.(*Pointer); !ok && !IsInterface(typ) { + typ = &Pointer{base: typ} + } + } + // If we created a synthetic pointer type above, we will throw + // away the method set computed here after use. + // TODO(gri) Method set computation should probably always compute + // both, the value and the pointer receiver method set and represent + // them in a single structure. + // TODO(gri) Consider also using a method set cache for the lifetime + // of checker once we rely on MethodSet lookup instead of individual + // lookup. + mset := NewMethodSet(typ) + if m := mset.Lookup(check.pkg, sel); m == nil || m.obj != obj { + check.dump("%s: (%s).%v -> %s", e.Pos(), typ, obj.name, m) + check.dump("%s\n", mset) + panic("method sets and lookup don't agree") + } + } + + x.mode = value + + // remove receiver + sig := *obj.typ.(*Signature) + sig.recv = nil + x.typ = &sig + + check.addDeclDep(obj) + + default: + unreachable() + } + } + + // everything went well + x.expr = e + return + +Error: + x.mode = invalid + x.expr = e +} diff --git a/third_party/forked/golang/go/types/check.go b/third_party/forked/golang/go/types/check.go new file mode 100644 index 00000000000..26db5769b98 --- /dev/null +++ b/third_party/forked/golang/go/types/check.go @@ -0,0 +1,371 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements the Check function, which drives type-checking. + +package types + +import ( + "go/ast" + "go/constant" + "go/token" +) + +// debugging/development support +const ( + debug = false // leave on during development + trace = false // turn on for detailed type resolution traces +) + +// If Strict is set, the type-checker enforces additional +// rules not specified by the Go 1 spec, but which will +// catch guaranteed run-time errors if the respective +// code is executed. In other words, programs passing in +// Strict mode are Go 1 compliant, but not all Go 1 programs +// will pass in Strict mode. The additional rules are: +// +// - A type assertion x.(T) where T is an interface type +// is invalid if any (statically known) method that exists +// for both x and T have different signatures. +// +const strict = false + +// exprInfo stores information about an untyped expression. +type exprInfo struct { + isLhs bool // expression is lhs operand of a shift with delayed type-check + mode operandMode + typ *Basic + val constant.Value // constant value; or nil (if not a constant) +} + +// funcInfo stores the information required for type-checking a function. +type funcInfo struct { + name string // for debugging/tracing only + decl *declInfo // for cycle detection + sig *Signature + body *ast.BlockStmt +} + +// A context represents the context within which an object is type-checked. +type context struct { + decl *declInfo // package-level declaration whose init expression/function body is checked + scope *Scope // top-most scope for lookups + iota constant.Value // value of iota in a constant declaration; nil otherwise + sig *Signature // function signature if inside a function; nil otherwise + hasLabel bool // set if a function makes use of labels (only ~1% of functions); unused outside functions + hasCallOrRecv bool // set if an expression contains a function call or channel receive operation +} + +// An importKey identifies an imported package by import path and source directory +// (directory containing the file containing the import). In practice, the directory +// may always be the same, or may not matter. Given an (import path, directory), an +// importer must always return the same package (but given two different import paths, +// an importer may still return the same package by mapping them to the same package +// paths). +type importKey struct { + path, dir string +} + +// A Checker maintains the state of the type checker. +// It must be created with NewChecker. +type Checker struct { + // package information + // (initialized by NewChecker, valid for the life-time of checker) + conf *Config + fset *token.FileSet + pkg *Package + *Info + objMap map[Object]*declInfo // maps package-level object to declaration info + impMap map[importKey]*Package // maps (import path, source directory) to (complete or fake) package + + // information collected during type-checking of a set of package files + // (initialized by Files, valid only for the duration of check.Files; + // maps and lists are allocated on demand) + files []*ast.File // package files + unusedDotImports map[*Scope]map[*Package]token.Pos // positions of unused dot-imported packages for each file scope + + firstErr error // first error encountered + methods map[string][]*Func // maps type names to associated methods + untyped map[ast.Expr]exprInfo // map of expressions without final type + funcs []funcInfo // list of functions to type-check + delayed []func() // delayed checks requiring fully setup types + + // context within which the current object is type-checked + // (valid only for the duration of type-checking a specific object) + context + pos token.Pos // if valid, identifiers are looked up as if at position pos (used by Eval) + + // debugging + indent int // indentation for tracing +} + +// addUnusedImport adds the position of a dot-imported package +// pkg to the map of dot imports for the given file scope. +func (check *Checker) addUnusedDotImport(scope *Scope, pkg *Package, pos token.Pos) { + mm := check.unusedDotImports + if mm == nil { + mm = make(map[*Scope]map[*Package]token.Pos) + check.unusedDotImports = mm + } + m := mm[scope] + if m == nil { + m = make(map[*Package]token.Pos) + mm[scope] = m + } + m[pkg] = pos +} + +// addDeclDep adds the dependency edge (check.decl -> to) if check.decl exists +func (check *Checker) addDeclDep(to Object) { + from := check.decl + if from == nil { + return // not in a package-level init expression + } + if _, found := check.objMap[to]; !found { + return // to is not a package-level object + } + from.addDep(to) +} + +func (check *Checker) assocMethod(tname string, meth *Func) { + m := check.methods + if m == nil { + m = make(map[string][]*Func) + check.methods = m + } + m[tname] = append(m[tname], meth) +} + +func (check *Checker) rememberUntyped(e ast.Expr, lhs bool, mode operandMode, typ *Basic, val constant.Value) { + m := check.untyped + if m == nil { + m = make(map[ast.Expr]exprInfo) + check.untyped = m + } + m[e] = exprInfo{lhs, mode, typ, val} +} + +func (check *Checker) later(name string, decl *declInfo, sig *Signature, body *ast.BlockStmt) { + check.funcs = append(check.funcs, funcInfo{name, decl, sig, body}) +} + +func (check *Checker) delay(f func()) { + check.delayed = append(check.delayed, f) +} + +// NewChecker returns a new Checker instance for a given package. +// Package files may be added incrementally via checker.Files. +func NewChecker(conf *Config, fset *token.FileSet, pkg *Package, info *Info) *Checker { + // make sure we have a configuration + if conf == nil { + conf = new(Config) + } + + // make sure we have an info struct + if info == nil { + info = new(Info) + } + + return &Checker{ + conf: conf, + fset: fset, + pkg: pkg, + Info: info, + objMap: make(map[Object]*declInfo), + impMap: make(map[importKey]*Package), + } +} + +// initFiles initializes the files-specific portion of checker. +// The provided files must all belong to the same package. +func (check *Checker) initFiles(files []*ast.File) { + // start with a clean slate (check.Files may be called multiple times) + check.files = nil + check.unusedDotImports = nil + + check.firstErr = nil + check.methods = nil + check.untyped = nil + check.funcs = nil + check.delayed = nil + + // determine package name and collect valid files + pkg := check.pkg + for _, file := range files { + switch name := file.Name.Name; pkg.name { + case "": + if name != "_" { + pkg.name = name + } else { + check.errorf(file.Name.Pos(), "invalid package name _") + } + fallthrough + + case name: + check.files = append(check.files, file) + + default: + check.errorf(file.Package, "package %s; expected %s", name, pkg.name) + // ignore this file + } + } +} + +// A bailout panic is used for early termination. +type bailout struct{} + +func (check *Checker) handleBailout(err *error) { + switch p := recover().(type) { + case nil, bailout: + // normal return or early exit + *err = check.firstErr + default: + // re-panic + panic(p) + } +} + +// Files checks the provided files as part of the checker's package. +func (check *Checker) Files(files []*ast.File) error { return check.checkFiles(files) } + +func (check *Checker) checkFiles(files []*ast.File) (err error) { + defer check.handleBailout(&err) + + check.initFiles(files) + + check.collectObjects() + + check.packageObjects(check.resolveOrder()) + + check.functionBodies() + + check.initOrder() + + if !check.conf.DisableUnusedImportCheck { + check.unusedImports() + } + + // perform delayed checks + for _, f := range check.delayed { + f() + } + + check.recordUntyped() + + check.pkg.complete = true + return +} + +func (check *Checker) recordUntyped() { + if !debug && check.Types == nil { + return // nothing to do + } + + for x, info := range check.untyped { + if debug && isTyped(info.typ) { + check.dump("%s: %s (type %s) is typed", x.Pos(), x, info.typ) + unreachable() + } + check.recordTypeAndValue(x, info.mode, info.typ, info.val) + } +} + +func (check *Checker) recordTypeAndValue(x ast.Expr, mode operandMode, typ Type, val constant.Value) { + assert(x != nil) + assert(typ != nil) + if mode == invalid { + return // omit + } + assert(typ != nil) + if mode == constant_ { + assert(val != nil) + assert(typ == Typ[Invalid] || isConstType(typ)) + } + if m := check.Types; m != nil { + m[x] = TypeAndValue{mode, typ, val} + } +} + +func (check *Checker) recordBuiltinType(f ast.Expr, sig *Signature) { + // f must be a (possibly parenthesized) identifier denoting a built-in + // (built-ins in package unsafe always produce a constant result and + // we don't record their signatures, so we don't see qualified idents + // here): record the signature for f and possible children. + for { + check.recordTypeAndValue(f, builtin, sig, nil) + switch p := f.(type) { + case *ast.Ident: + return // we're done + case *ast.ParenExpr: + f = p.X + default: + unreachable() + } + } +} + +func (check *Checker) recordCommaOkTypes(x ast.Expr, a [2]Type) { + assert(x != nil) + if a[0] == nil || a[1] == nil { + return + } + assert(isTyped(a[0]) && isTyped(a[1]) && isBoolean(a[1])) + if m := check.Types; m != nil { + for { + tv := m[x] + assert(tv.Type != nil) // should have been recorded already + pos := x.Pos() + tv.Type = NewTuple( + NewVar(pos, check.pkg, "", a[0]), + NewVar(pos, check.pkg, "", a[1]), + ) + m[x] = tv + // if x is a parenthesized expression (p.X), update p.X + p, _ := x.(*ast.ParenExpr) + if p == nil { + break + } + x = p.X + } + } +} + +func (check *Checker) recordDef(id *ast.Ident, obj Object) { + assert(id != nil) + if m := check.Defs; m != nil { + m[id] = obj + } +} + +func (check *Checker) recordUse(id *ast.Ident, obj Object) { + assert(id != nil) + assert(obj != nil) + if m := check.Uses; m != nil { + m[id] = obj + } +} + +func (check *Checker) recordImplicit(node ast.Node, obj Object) { + assert(node != nil) + assert(obj != nil) + if m := check.Implicits; m != nil { + m[node] = obj + } +} + +func (check *Checker) recordSelection(x *ast.SelectorExpr, kind SelectionKind, recv Type, obj Object, index []int, indirect bool) { + assert(obj != nil && (recv == nil || len(index) > 0)) + check.recordUse(x.Sel, obj) + if m := check.Selections; m != nil { + m[x] = &Selection{kind, recv, obj, index, indirect} + } +} + +func (check *Checker) recordScope(node ast.Node, scope *Scope) { + assert(node != nil) + assert(scope != nil) + if m := check.Scopes; m != nil { + m[node] = scope + } +} diff --git a/third_party/forked/golang/go/types/conversions.go b/third_party/forked/golang/go/types/conversions.go new file mode 100644 index 00000000000..81a65838fe0 --- /dev/null +++ b/third_party/forked/golang/go/types/conversions.go @@ -0,0 +1,160 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements typechecking of conversions. + +package types + +import "go/constant" + +// Conversion type-checks the conversion T(x). +// The result is in x. +func (check *Checker) conversion(x *operand, T Type) { + constArg := x.mode == constant_ + + var ok bool + switch { + case constArg && isConstType(T): + // constant conversion + switch t := T.Underlying().(*Basic); { + case representableConst(x.val, check.conf, t, &x.val): + ok = true + case isInteger(x.typ) && isString(t): + codepoint := int64(-1) + if i, ok := constant.Int64Val(x.val); ok { + codepoint = i + } + // If codepoint < 0 the absolute value is too large (or unknown) for + // conversion. This is the same as converting any other out-of-range + // value - let string(codepoint) do the work. + x.val = constant.MakeString(string(codepoint)) + ok = true + } + case x.convertibleTo(check.conf, T): + // non-constant conversion + x.mode = value + ok = true + } + + if !ok { + check.errorf(x.pos(), "cannot convert %s to %s", x, T) + x.mode = invalid + return + } + + // The conversion argument types are final. For untyped values the + // conversion provides the type, per the spec: "A constant may be + // given a type explicitly by a constant declaration or conversion,...". + if isUntyped(x.typ) { + final := T + // - For conversions to interfaces, use the argument's default type. + // - For conversions of untyped constants to non-constant types, also + // use the default type (e.g., []byte("foo") should report string + // not []byte as type for the constant "foo"). + // - Keep untyped nil for untyped nil arguments. + // - For integer to string conversions, keep the argument type. + // (See also the TODO below.) + if IsInterface(T) || constArg && !isConstType(T) { + final = Default(x.typ) + } else if isInteger(x.typ) && isString(T) { + final = x.typ + } + check.updateExprType(x.expr, final, true) + } + + x.typ = T +} + +// TODO(gri) convertibleTo checks if T(x) is valid. It assumes that the type +// of x is fully known, but that's not the case for say string(1< %s", obj) + }() + } + + d := check.objMap[obj] + if d == nil { + check.dump("%s: %s should have been declared", obj.Pos(), obj.Name()) + unreachable() + } + + // save/restore current context and setup object context + defer func(ctxt context) { + check.context = ctxt + }(check.context) + check.context = context{ + scope: d.file, + } + + // Const and var declarations must not have initialization + // cycles. We track them by remembering the current declaration + // in check.decl. Initialization expressions depending on other + // consts, vars, or functions, add dependencies to the current + // check.decl. + switch obj := obj.(type) { + case *Const: + check.decl = d // new package-level const decl + check.constDecl(obj, d.typ, d.init) + case *Var: + check.decl = d // new package-level var decl + check.varDecl(obj, d.lhs, d.typ, d.init) + case *TypeName: + // invalid recursive types are detected via path + check.typeDecl(obj, d.typ, def, path, d.alias) + case *Func: + // functions may be recursive - no need to track dependencies + check.funcDecl(obj, d) + default: + unreachable() + } +} + +func (check *Checker) constDecl(obj *Const, typ, init ast.Expr) { + assert(obj.typ == nil) + + if obj.visited { + obj.typ = Typ[Invalid] + return + } + obj.visited = true + + // use the correct value of iota + assert(check.iota == nil) + check.iota = obj.val + defer func() { check.iota = nil }() + + // provide valid constant value under all circumstances + obj.val = constant.MakeUnknown() + + // determine type, if any + if typ != nil { + t := check.typ(typ) + if !isConstType(t) { + // don't report an error if the type is an invalid C (defined) type + // (issue #22090) + if t.Underlying() != Typ[Invalid] { + check.errorf(typ.Pos(), "invalid constant type %s", t) + } + obj.typ = Typ[Invalid] + return + } + obj.typ = t + } + + // check initialization + var x operand + if init != nil { + check.expr(&x, init) + } + check.initConst(obj, &x) +} + +func (check *Checker) varDecl(obj *Var, lhs []*Var, typ, init ast.Expr) { + assert(obj.typ == nil) + + if obj.visited { + obj.typ = Typ[Invalid] + return + } + obj.visited = true + + // var declarations cannot use iota + assert(check.iota == nil) + + // determine type, if any + if typ != nil { + obj.typ = check.typ(typ) + // We cannot spread the type to all lhs variables if there + // are more than one since that would mark them as checked + // (see Checker.objDecl) and the assignment of init exprs, + // if any, would not be checked. + // + // TODO(gri) If we have no init expr, we should distribute + // a given type otherwise we need to re-evalate the type + // expr for each lhs variable, leading to duplicate work. + } + + // check initialization + if init == nil { + if typ == nil { + // error reported before by arityMatch + obj.typ = Typ[Invalid] + } + return + } + + if lhs == nil || len(lhs) == 1 { + assert(lhs == nil || lhs[0] == obj) + var x operand + check.expr(&x, init) + check.initVar(obj, &x, "variable declaration") + return + } + + if debug { + // obj must be one of lhs + found := false + for _, lhs := range lhs { + if obj == lhs { + found = true + break + } + } + if !found { + panic("inconsistent lhs") + } + } + + // We have multiple variables on the lhs and one init expr. + // Make sure all variables have been given the same type if + // one was specified, otherwise they assume the type of the + // init expression values (was issue #15755). + if typ != nil { + for _, lhs := range lhs { + lhs.typ = obj.typ + } + } + + check.initVars(lhs, []ast.Expr{init}, token.NoPos) +} + +// underlying returns the underlying type of typ; possibly by following +// forward chains of named types. Such chains only exist while named types +// are incomplete. +func underlying(typ Type) Type { + for { + n, _ := typ.(*Named) + if n == nil { + break + } + typ = n.underlying + } + return typ +} + +func (n *Named) setUnderlying(typ Type) { + if n != nil { + n.underlying = typ + } +} + +func (check *Checker) typeDecl(obj *TypeName, typ ast.Expr, def *Named, path []*TypeName, alias bool) { + assert(obj.typ == nil) + + // type declarations cannot use iota + assert(check.iota == nil) + + if alias { + + obj.typ = Typ[Invalid] + obj.typ = check.typExpr(typ, nil, append(path, obj)) + + } else { + + named := &Named{obj: obj} + def.setUnderlying(named) + obj.typ = named // make sure recursive type declarations terminate + + // determine underlying type of named + check.typExpr(typ, named, append(path, obj)) + + // The underlying type of named may be itself a named type that is + // incomplete: + // + // type ( + // A B + // B *C + // C A + // ) + // + // The type of C is the (named) type of A which is incomplete, + // and which has as its underlying type the named type B. + // Determine the (final, unnamed) underlying type by resolving + // any forward chain (they always end in an unnamed type). + named.underlying = underlying(named.underlying) + + } + + // check and add associated methods + // TODO(gri) It's easy to create pathological cases where the + // current approach is incorrect: In general we need to know + // and add all methods _before_ type-checking the type. + // See https://play.golang.org/p/WMpE0q2wK8 + check.addMethodDecls(obj) +} + +func (check *Checker) addMethodDecls(obj *TypeName) { + // get associated methods + methods := check.methods[obj.name] + if len(methods) == 0 { + return // no methods + } + delete(check.methods, obj.name) + + // use an objset to check for name conflicts + var mset objset + + // spec: "If the base type is a struct type, the non-blank method + // and field names must be distinct." + base, _ := obj.typ.(*Named) // nil if receiver base type is type alias + if base != nil { + if t, _ := base.underlying.(*Struct); t != nil { + for _, fld := range t.fields { + if fld.name != "_" { + assert(mset.insert(fld) == nil) + } + } + } + + // Checker.Files may be called multiple times; additional package files + // may add methods to already type-checked types. Add pre-existing methods + // so that we can detect redeclarations. + for _, m := range base.methods { + assert(m.name != "_") + assert(mset.insert(m) == nil) + } + } + + // type-check methods + for _, m := range methods { + // spec: "For a base type, the non-blank names of methods bound + // to it must be unique." + if m.name != "_" { + if alt := mset.insert(m); alt != nil { + switch alt.(type) { + case *Var: + check.errorf(m.pos, "field and method with the same name %s", m.name) + case *Func: + check.errorf(m.pos, "method %s already declared for %s", m.name, obj) + default: + unreachable() + } + check.reportAltDecl(alt) + continue + } + } + + // type-check + check.objDecl(m, nil, nil) + + // methods with blank _ names cannot be found - don't keep them + if base != nil && m.name != "_" { + base.methods = append(base.methods, m) + } + } +} + +func (check *Checker) funcDecl(obj *Func, decl *declInfo) { + assert(obj.typ == nil) + + // func declarations cannot use iota + assert(check.iota == nil) + + sig := new(Signature) + obj.typ = sig // guard against cycles + fdecl := decl.fdecl + check.funcType(sig, fdecl.Recv, fdecl.Type) + if sig.recv == nil && obj.name == "init" && (sig.params.Len() > 0 || sig.results.Len() > 0) { + check.errorf(fdecl.Pos(), "func init must have no arguments and no return values") + // ok to continue + } + + // function body must be type-checked after global declarations + // (functions implemented elsewhere have no body) + if !check.conf.IgnoreFuncBodies && fdecl.Body != nil { + check.later(obj.name, decl, sig, fdecl.Body) + } +} + +func (check *Checker) declStmt(decl ast.Decl) { + pkg := check.pkg + + switch d := decl.(type) { + case *ast.BadDecl: + // ignore + + case *ast.GenDecl: + var last *ast.ValueSpec // last ValueSpec with type or init exprs seen + for iota, spec := range d.Specs { + switch s := spec.(type) { + case *ast.ValueSpec: + switch d.Tok { + case token.CONST: + // determine which init exprs to use + switch { + case s.Type != nil || len(s.Values) > 0: + last = s + case last == nil: + last = new(ast.ValueSpec) // make sure last exists + } + + // declare all constants + lhs := make([]*Const, len(s.Names)) + for i, name := range s.Names { + obj := NewConst(name.Pos(), pkg, name.Name, nil, constant.MakeInt64(int64(iota))) + lhs[i] = obj + + var init ast.Expr + if i < len(last.Values) { + init = last.Values[i] + } + + check.constDecl(obj, last.Type, init) + } + + check.arityMatch(s, last) + + // spec: "The scope of a constant or variable identifier declared + // inside a function begins at the end of the ConstSpec or VarSpec + // (ShortVarDecl for short variable declarations) and ends at the + // end of the innermost containing block." + scopePos := s.End() + for i, name := range s.Names { + check.declare(check.scope, name, lhs[i], scopePos) + } + + case token.VAR: + lhs0 := make([]*Var, len(s.Names)) + for i, name := range s.Names { + lhs0[i] = NewVar(name.Pos(), pkg, name.Name, nil) + } + + // initialize all variables + for i, obj := range lhs0 { + var lhs []*Var + var init ast.Expr + switch len(s.Values) { + case len(s.Names): + // lhs and rhs match + init = s.Values[i] + case 1: + // rhs is expected to be a multi-valued expression + lhs = lhs0 + init = s.Values[0] + default: + if i < len(s.Values) { + init = s.Values[i] + } + } + check.varDecl(obj, lhs, s.Type, init) + if len(s.Values) == 1 { + // If we have a single lhs variable we are done either way. + // If we have a single rhs expression, it must be a multi- + // valued expression, in which case handling the first lhs + // variable will cause all lhs variables to have a type + // assigned, and we are done as well. + if debug { + for _, obj := range lhs0 { + assert(obj.typ != nil) + } + } + break + } + } + + check.arityMatch(s, nil) + + // declare all variables + // (only at this point are the variable scopes (parents) set) + scopePos := s.End() // see constant declarations + for i, name := range s.Names { + // see constant declarations + check.declare(check.scope, name, lhs0[i], scopePos) + } + + default: + check.invalidAST(s.Pos(), "invalid token %s", d.Tok) + } + + case *ast.TypeSpec: + obj := NewTypeName(s.Name.Pos(), pkg, s.Name.Name, nil) + // spec: "The scope of a type identifier declared inside a function + // begins at the identifier in the TypeSpec and ends at the end of + // the innermost containing block." + scopePos := s.Name.Pos() + check.declare(check.scope, s.Name, obj, scopePos) + check.typeDecl(obj, s.Type, nil, nil, s.Assign.IsValid()) + + default: + check.invalidAST(s.Pos(), "const, type, or var declaration expected") + } + } + + default: + check.invalidAST(d.Pos(), "unknown ast.Decl node %T", d) + } +} diff --git a/third_party/forked/golang/go/types/errors.go b/third_party/forked/golang/go/types/errors.go new file mode 100644 index 00000000000..0c0049b1f3e --- /dev/null +++ b/third_party/forked/golang/go/types/errors.go @@ -0,0 +1,103 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements various error reporters. + +package types + +import ( + "fmt" + "go/ast" + "go/token" + "strings" +) + +func assert(p bool) { + if !p { + panic("assertion failed") + } +} + +func unreachable() { + panic("unreachable") +} + +func (check *Checker) qualifier(pkg *Package) string { + if pkg != check.pkg { + return pkg.path + } + return "" +} + +func (check *Checker) sprintf(format string, args ...interface{}) string { + for i, arg := range args { + switch a := arg.(type) { + case nil: + arg = "" + case operand: + panic("internal error: should always pass *operand") + case *operand: + arg = operandString(a, check.qualifier) + case token.Pos: + arg = check.fset.Position(a).String() + case ast.Expr: + arg = ExprString(a) + case Object: + arg = ObjectString(a, check.qualifier) + case Type: + arg = TypeString(a, check.qualifier) + } + args[i] = arg + } + return fmt.Sprintf(format, args...) +} + +func (check *Checker) trace(pos token.Pos, format string, args ...interface{}) { + fmt.Printf("%s:\t%s%s\n", + check.fset.Position(pos), + strings.Repeat(". ", check.indent), + check.sprintf(format, args...), + ) +} + +// dump is only needed for debugging +func (check *Checker) dump(format string, args ...interface{}) { + fmt.Println(check.sprintf(format, args...)) +} + +func (check *Checker) err(pos token.Pos, msg string, soft bool) { + err := Error{check.fset, pos, msg, soft} + if check.firstErr == nil { + check.firstErr = err + } + f := check.conf.Error + if f == nil { + panic(bailout{}) // report only first error + } + f(err) +} + +func (check *Checker) error(pos token.Pos, msg string) { + check.err(pos, msg, false) +} + +func (check *Checker) errorf(pos token.Pos, format string, args ...interface{}) { + check.err(pos, check.sprintf(format, args...), false) +} + +func (check *Checker) softErrorf(pos token.Pos, format string, args ...interface{}) { + check.err(pos, check.sprintf(format, args...), true) +} + +func (check *Checker) invalidAST(pos token.Pos, format string, args ...interface{}) { + check.errorf(pos, "invalid AST: "+format, args...) +} + +func (check *Checker) invalidArg(pos token.Pos, format string, args ...interface{}) { + check.errorf(pos, "invalid argument: "+format, args...) +} + +func (check *Checker) invalidOp(pos token.Pos, format string, args ...interface{}) { + check.errorf(pos, "invalid operation: "+format, args...) +} diff --git a/third_party/forked/golang/go/types/eval.go b/third_party/forked/golang/go/types/eval.go new file mode 100644 index 00000000000..831d771d807 --- /dev/null +++ b/third_party/forked/golang/go/types/eval.go @@ -0,0 +1,83 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package types + +import ( + "fmt" + "go/parser" + "go/token" +) + +// Eval returns the type and, if constant, the value for the +// expression expr, evaluated at position pos of package pkg, +// which must have been derived from type-checking an AST with +// complete position information relative to the provided file +// set. +// +// If the expression contains function literals, their bodies +// are ignored (i.e., the bodies are not type-checked). +// +// If pkg == nil, the Universe scope is used and the provided +// position pos is ignored. If pkg != nil, and pos is invalid, +// the package scope is used. Otherwise, pos must belong to the +// package. +// +// An error is returned if pos is not within the package or +// if the node cannot be evaluated. +// +// Note: Eval should not be used instead of running Check to compute +// types and values, but in addition to Check. Eval will re-evaluate +// its argument each time, and it also does not know about the context +// in which an expression is used (e.g., an assignment). Thus, top- +// level untyped constants will return an untyped type rather then the +// respective context-specific type. +// +func Eval(fset *token.FileSet, pkg *Package, pos token.Pos, expr string) (TypeAndValue, error) { + // determine scope + var scope *Scope + if pkg == nil { + scope = Universe + pos = token.NoPos + } else if !pos.IsValid() { + scope = pkg.scope + } else { + // The package scope extent (position information) may be + // incorrect (files spread across a wide range of fset + // positions) - ignore it and just consider its children + // (file scopes). + for _, fscope := range pkg.scope.children { + if scope = fscope.Innermost(pos); scope != nil { + break + } + } + if scope == nil || debug { + s := scope + for s != nil && s != pkg.scope { + s = s.parent + } + // s == nil || s == pkg.scope + if s == nil { + return TypeAndValue{}, fmt.Errorf("no position %s found in package %s", fset.Position(pos), pkg.name) + } + } + } + + // parse expressions + node, err := parser.ParseExprFrom(fset, "eval", expr, 0) + if err != nil { + return TypeAndValue{}, err + } + + // initialize checker + check := NewChecker(nil, fset, pkg, nil) + check.scope = scope + check.pos = pos + defer check.handleBailout(&err) + + // evaluate node + var x operand + check.rawExpr(&x, node, nil) + return TypeAndValue{x.mode, x.typ, x.val}, err +} diff --git a/third_party/forked/golang/go/types/expr.go b/third_party/forked/golang/go/types/expr.go new file mode 100644 index 00000000000..59534c75708 --- /dev/null +++ b/third_party/forked/golang/go/types/expr.go @@ -0,0 +1,1623 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements typechecking of expressions. + +package types + +import ( + "fmt" + "go/ast" + "go/constant" + "go/token" + "math" +) + +/* +Basic algorithm: + +Expressions are checked recursively, top down. Expression checker functions +are generally of the form: + + func f(x *operand, e *ast.Expr, ...) + +where e is the expression to be checked, and x is the result of the check. +The check performed by f may fail in which case x.mode == invalid, and +related error messages will have been issued by f. + +If a hint argument is present, it is the composite literal element type +of an outer composite literal; it is used to type-check composite literal +elements that have no explicit type specification in the source +(e.g.: []T{{...}, {...}}, the hint is the type T in this case). + +All expressions are checked via rawExpr, which dispatches according +to expression kind. Upon returning, rawExpr is recording the types and +constant values for all expressions that have an untyped type (those types +may change on the way up in the expression tree). Usually these are constants, +but the results of comparisons or non-constant shifts of untyped constants +may also be untyped, but not constant. + +Untyped expressions may eventually become fully typed (i.e., not untyped), +typically when the value is assigned to a variable, or is used otherwise. +The updateExprType method is used to record this final type and update +the recorded types: the type-checked expression tree is again traversed down, +and the new type is propagated as needed. Untyped constant expression values +that become fully typed must now be representable by the full type (constant +sub-expression trees are left alone except for their roots). This mechanism +ensures that a client sees the actual (run-time) type an untyped value would +have. It also permits type-checking of lhs shift operands "as if the shift +were not present": when updateExprType visits an untyped lhs shift operand +and assigns it it's final type, that type must be an integer type, and a +constant lhs must be representable as an integer. + +When an expression gets its final type, either on the way out from rawExpr, +on the way down in updateExprType, or at the end of the type checker run, +the type (and constant value, if any) is recorded via Info.Types, if present. +*/ + +type opPredicates map[token.Token]func(Type) bool + +var unaryOpPredicates = opPredicates{ + token.ADD: isNumeric, + token.SUB: isNumeric, + token.XOR: isInteger, + token.NOT: isBoolean, +} + +func (check *Checker) op(m opPredicates, x *operand, op token.Token) bool { + if pred := m[op]; pred != nil { + if !pred(x.typ) { + check.invalidOp(x.pos(), "operator %s not defined for %s", op, x) + return false + } + } else { + check.invalidAST(x.pos(), "unknown operator %s", op) + return false + } + return true +} + +// The unary expression e may be nil. It's passed in for better error messages only. +func (check *Checker) unary(x *operand, e *ast.UnaryExpr, op token.Token) { + switch op { + case token.AND: + // spec: "As an exception to the addressability + // requirement x may also be a composite literal." + if _, ok := unparen(x.expr).(*ast.CompositeLit); !ok && x.mode != variable { + check.invalidOp(x.pos(), "cannot take address of %s", x) + x.mode = invalid + return + } + x.mode = value + x.typ = &Pointer{base: x.typ} + return + + case token.ARROW: + typ, ok := x.typ.Underlying().(*Chan) + if !ok { + check.invalidOp(x.pos(), "cannot receive from non-channel %s", x) + x.mode = invalid + return + } + if typ.dir == SendOnly { + check.invalidOp(x.pos(), "cannot receive from send-only channel %s", x) + x.mode = invalid + return + } + x.mode = commaok + x.typ = typ.elem + check.hasCallOrRecv = true + return + } + + if !check.op(unaryOpPredicates, x, op) { + x.mode = invalid + return + } + + if x.mode == constant_ { + typ := x.typ.Underlying().(*Basic) + var prec uint + if isUnsigned(typ) { + prec = uint(check.conf.sizeof(typ) * 8) + } + x.val = constant.UnaryOp(op, x.val, prec) + // Typed constants must be representable in + // their type after each constant operation. + if isTyped(typ) { + if e != nil { + x.expr = e // for better error message + } + check.representable(x, typ) + } + return + } + + x.mode = value + // x.typ remains unchanged +} + +func isShift(op token.Token) bool { + return op == token.SHL || op == token.SHR +} + +func isComparison(op token.Token) bool { + // Note: tokens are not ordered well to make this much easier + switch op { + case token.EQL, token.NEQ, token.LSS, token.LEQ, token.GTR, token.GEQ: + return true + } + return false +} + +func fitsFloat32(x constant.Value) bool { + f32, _ := constant.Float32Val(x) + f := float64(f32) + return !math.IsInf(f, 0) +} + +func roundFloat32(x constant.Value) constant.Value { + f32, _ := constant.Float32Val(x) + f := float64(f32) + if !math.IsInf(f, 0) { + return constant.MakeFloat64(f) + } + return nil +} + +func fitsFloat64(x constant.Value) bool { + f, _ := constant.Float64Val(x) + return !math.IsInf(f, 0) +} + +func roundFloat64(x constant.Value) constant.Value { + f, _ := constant.Float64Val(x) + if !math.IsInf(f, 0) { + return constant.MakeFloat64(f) + } + return nil +} + +// representableConst reports whether x can be represented as +// value of the given basic type and for the configuration +// provided (only needed for int/uint sizes). +// +// If rounded != nil, *rounded is set to the rounded value of x for +// representable floating-point and complex values, and to an Int +// value for integer values; it is left alone otherwise. +// It is ok to provide the addressof the first argument for rounded. +func representableConst(x constant.Value, conf *Config, typ *Basic, rounded *constant.Value) bool { + if x.Kind() == constant.Unknown { + return true // avoid follow-up errors + } + + switch { + case isInteger(typ): + x := constant.ToInt(x) + if x.Kind() != constant.Int { + return false + } + if rounded != nil { + *rounded = x + } + if x, ok := constant.Int64Val(x); ok { + switch typ.kind { + case Int: + var s = uint(conf.sizeof(typ)) * 8 + return int64(-1)<<(s-1) <= x && x <= int64(1)<<(s-1)-1 + case Int8: + const s = 8 + return -1<<(s-1) <= x && x <= 1<<(s-1)-1 + case Int16: + const s = 16 + return -1<<(s-1) <= x && x <= 1<<(s-1)-1 + case Int32: + const s = 32 + return -1<<(s-1) <= x && x <= 1<<(s-1)-1 + case Int64, UntypedInt: + return true + case Uint, Uintptr: + if s := uint(conf.sizeof(typ)) * 8; s < 64 { + return 0 <= x && x <= int64(1)<= 0 && n <= int(s) + case Uint64: + return constant.Sign(x) >= 0 && n <= 64 + case UntypedInt: + return true + } + + case isFloat(typ): + x := constant.ToFloat(x) + if x.Kind() != constant.Float { + return false + } + switch typ.kind { + case Float32: + if rounded == nil { + return fitsFloat32(x) + } + r := roundFloat32(x) + if r != nil { + *rounded = r + return true + } + case Float64: + if rounded == nil { + return fitsFloat64(x) + } + r := roundFloat64(x) + if r != nil { + *rounded = r + return true + } + case UntypedFloat: + return true + default: + unreachable() + } + + case isComplex(typ): + x := constant.ToComplex(x) + if x.Kind() != constant.Complex { + return false + } + switch typ.kind { + case Complex64: + if rounded == nil { + return fitsFloat32(constant.Real(x)) && fitsFloat32(constant.Imag(x)) + } + re := roundFloat32(constant.Real(x)) + im := roundFloat32(constant.Imag(x)) + if re != nil && im != nil { + *rounded = constant.BinaryOp(re, token.ADD, constant.MakeImag(im)) + return true + } + case Complex128: + if rounded == nil { + return fitsFloat64(constant.Real(x)) && fitsFloat64(constant.Imag(x)) + } + re := roundFloat64(constant.Real(x)) + im := roundFloat64(constant.Imag(x)) + if re != nil && im != nil { + *rounded = constant.BinaryOp(re, token.ADD, constant.MakeImag(im)) + return true + } + case UntypedComplex: + return true + default: + unreachable() + } + + case isString(typ): + return x.Kind() == constant.String + + case isBoolean(typ): + return x.Kind() == constant.Bool + } + + return false +} + +// representable checks that a constant operand is representable in the given basic type. +func (check *Checker) representable(x *operand, typ *Basic) { + assert(x.mode == constant_) + if !representableConst(x.val, check.conf, typ, &x.val) { + var msg string + if isNumeric(x.typ) && isNumeric(typ) { + // numeric conversion : error msg + // + // integer -> integer : overflows + // integer -> float : overflows (actually not possible) + // float -> integer : truncated + // float -> float : overflows + // + if !isInteger(x.typ) && isInteger(typ) { + msg = "%s truncated to %s" + } else { + msg = "%s overflows %s" + } + } else { + msg = "cannot convert %s to %s" + } + check.errorf(x.pos(), msg, x, typ) + x.mode = invalid + } +} + +// updateExprType updates the type of x to typ and invokes itself +// recursively for the operands of x, depending on expression kind. +// If typ is still an untyped and not the final type, updateExprType +// only updates the recorded untyped type for x and possibly its +// operands. Otherwise (i.e., typ is not an untyped type anymore, +// or it is the final type for x), the type and value are recorded. +// Also, if x is a constant, it must be representable as a value of typ, +// and if x is the (formerly untyped) lhs operand of a non-constant +// shift, it must be an integer value. +// +func (check *Checker) updateExprType(x ast.Expr, typ Type, final bool) { + old, found := check.untyped[x] + if !found { + return // nothing to do + } + + // update operands of x if necessary + switch x := x.(type) { + case *ast.BadExpr, + *ast.FuncLit, + *ast.CompositeLit, + *ast.IndexExpr, + *ast.SliceExpr, + *ast.TypeAssertExpr, + *ast.StarExpr, + *ast.KeyValueExpr, + *ast.ArrayType, + *ast.StructType, + *ast.FuncType, + *ast.InterfaceType, + *ast.MapType, + *ast.ChanType: + // These expression are never untyped - nothing to do. + // The respective sub-expressions got their final types + // upon assignment or use. + if debug { + check.dump("%s: found old type(%s): %s (new: %s)", x.Pos(), x, old.typ, typ) + unreachable() + } + return + + case *ast.CallExpr: + // Resulting in an untyped constant (e.g., built-in complex). + // The respective calls take care of calling updateExprType + // for the arguments if necessary. + + case *ast.Ident, *ast.BasicLit, *ast.SelectorExpr: + // An identifier denoting a constant, a constant literal, + // or a qualified identifier (imported untyped constant). + // No operands to take care of. + + case *ast.ParenExpr: + check.updateExprType(x.X, typ, final) + + case *ast.UnaryExpr: + // If x is a constant, the operands were constants. + // The operands don't need to be updated since they + // never get "materialized" into a typed value. If + // left in the untyped map, they will be processed + // at the end of the type check. + if old.val != nil { + break + } + check.updateExprType(x.X, typ, final) + + case *ast.BinaryExpr: + if old.val != nil { + break // see comment for unary expressions + } + if isComparison(x.Op) { + // The result type is independent of operand types + // and the operand types must have final types. + } else if isShift(x.Op) { + // The result type depends only on lhs operand. + // The rhs type was updated when checking the shift. + check.updateExprType(x.X, typ, final) + } else { + // The operand types match the result type. + check.updateExprType(x.X, typ, final) + check.updateExprType(x.Y, typ, final) + } + + default: + unreachable() + } + + // If the new type is not final and still untyped, just + // update the recorded type. + if !final && isUntyped(typ) { + old.typ = typ.Underlying().(*Basic) + check.untyped[x] = old + return + } + + // Otherwise we have the final (typed or untyped type). + // Remove it from the map of yet untyped expressions. + delete(check.untyped, x) + + if old.isLhs { + // If x is the lhs of a shift, its final type must be integer. + // We already know from the shift check that it is representable + // as an integer if it is a constant. + if !isInteger(typ) { + check.invalidOp(x.Pos(), "shifted operand %s (type %s) must be integer", x, typ) + return + } + } else if old.val != nil { + // If x is a constant, it must be representable as a value of typ. + c := operand{old.mode, x, old.typ, old.val, 0} + check.convertUntyped(&c, typ) + if c.mode == invalid { + return + } + } + + // Everything's fine, record final type and value for x. + check.recordTypeAndValue(x, old.mode, typ, old.val) +} + +// updateExprVal updates the value of x to val. +func (check *Checker) updateExprVal(x ast.Expr, val constant.Value) { + if info, ok := check.untyped[x]; ok { + info.val = val + check.untyped[x] = info + } +} + +// convertUntyped attempts to set the type of an untyped value to the target type. +func (check *Checker) convertUntyped(x *operand, target Type) { + if x.mode == invalid || isTyped(x.typ) || target == Typ[Invalid] { + return + } + + // TODO(gri) Sloppy code - clean up. This function is central + // to assignment and expression checking. + + if isUntyped(target) { + // both x and target are untyped + xkind := x.typ.(*Basic).kind + tkind := target.(*Basic).kind + if isNumeric(x.typ) && isNumeric(target) { + if xkind < tkind { + x.typ = target + check.updateExprType(x.expr, target, false) + } + } else if xkind != tkind { + goto Error + } + return + } + + // typed target + switch t := target.Underlying().(type) { + case *Basic: + if x.mode == constant_ { + check.representable(x, t) + if x.mode == invalid { + return + } + // expression value may have been rounded - update if needed + check.updateExprVal(x.expr, x.val) + } else { + // Non-constant untyped values may appear as the + // result of comparisons (untyped bool), intermediate + // (delayed-checked) rhs operands of shifts, and as + // the value nil. + switch x.typ.(*Basic).kind { + case UntypedBool: + if !isBoolean(target) { + goto Error + } + case UntypedInt, UntypedRune, UntypedFloat, UntypedComplex: + if !isNumeric(target) { + goto Error + } + case UntypedString: + // Non-constant untyped string values are not + // permitted by the spec and should not occur. + unreachable() + case UntypedNil: + // Unsafe.Pointer is a basic type that includes nil. + if !hasNil(target) { + goto Error + } + default: + goto Error + } + } + case *Interface: + if !x.isNil() && !t.Empty() /* empty interfaces are ok */ { + goto Error + } + // Update operand types to the default type rather then + // the target (interface) type: values must have concrete + // dynamic types. If the value is nil, keep it untyped + // (this is important for tools such as go vet which need + // the dynamic type for argument checking of say, print + // functions) + if x.isNil() { + target = Typ[UntypedNil] + } else { + // cannot assign untyped values to non-empty interfaces + if !t.Empty() { + goto Error + } + target = Default(x.typ) + } + case *Pointer, *Signature, *Slice, *Map, *Chan: + if !x.isNil() { + goto Error + } + // keep nil untyped - see comment for interfaces, above + target = Typ[UntypedNil] + default: + goto Error + } + + x.typ = target + check.updateExprType(x.expr, target, true) // UntypedNils are final + return + +Error: + check.errorf(x.pos(), "cannot convert %s to %s", x, target) + x.mode = invalid +} + +func (check *Checker) comparison(x, y *operand, op token.Token) { + // spec: "In any comparison, the first operand must be assignable + // to the type of the second operand, or vice versa." + err := "" + if x.assignableTo(check.conf, y.typ, nil) || y.assignableTo(check.conf, x.typ, nil) { + defined := false + switch op { + case token.EQL, token.NEQ: + // spec: "The equality operators == and != apply to operands that are comparable." + defined = Comparable(x.typ) || x.isNil() && hasNil(y.typ) || y.isNil() && hasNil(x.typ) + case token.LSS, token.LEQ, token.GTR, token.GEQ: + // spec: The ordering operators <, <=, >, and >= apply to operands that are ordered." + defined = isOrdered(x.typ) + default: + unreachable() + } + if !defined { + typ := x.typ + if x.isNil() { + typ = y.typ + } + err = check.sprintf("operator %s not defined for %s", op, typ) + } + } else { + err = check.sprintf("mismatched types %s and %s", x.typ, y.typ) + } + + if err != "" { + check.errorf(x.pos(), "cannot compare %s %s %s (%s)", x.expr, op, y.expr, err) + x.mode = invalid + return + } + + if x.mode == constant_ && y.mode == constant_ { + x.val = constant.MakeBool(constant.Compare(x.val, op, y.val)) + // The operands are never materialized; no need to update + // their types. + } else { + x.mode = value + // The operands have now their final types, which at run- + // time will be materialized. Update the expression trees. + // If the current types are untyped, the materialized type + // is the respective default type. + check.updateExprType(x.expr, Default(x.typ), true) + check.updateExprType(y.expr, Default(y.typ), true) + } + + // spec: "Comparison operators compare two operands and yield + // an untyped boolean value." + x.typ = Typ[UntypedBool] +} + +func (check *Checker) shift(x, y *operand, e *ast.BinaryExpr, op token.Token) { + untypedx := isUntyped(x.typ) + + var xval constant.Value + if x.mode == constant_ { + xval = constant.ToInt(x.val) + } + + if isInteger(x.typ) || untypedx && xval != nil && xval.Kind() == constant.Int { + // The lhs is of integer type or an untyped constant representable + // as an integer. Nothing to do. + } else { + // shift has no chance + check.invalidOp(x.pos(), "shifted operand %s must be integer", x) + x.mode = invalid + return + } + + // spec: "The right operand in a shift expression must have unsigned + // integer type or be an untyped constant representable by a value of + // type uint." + switch { + case isUnsigned(y.typ): + // nothing to do + case isUntyped(y.typ): + check.convertUntyped(y, Typ[Uint]) + if y.mode == invalid { + x.mode = invalid + return + } + default: + check.invalidOp(y.pos(), "shift count %s must be unsigned integer", y) + x.mode = invalid + return + } + + if x.mode == constant_ { + if y.mode == constant_ { + // rhs must be an integer value + yval := constant.ToInt(y.val) + if yval.Kind() != constant.Int { + check.invalidOp(y.pos(), "shift count %s must be unsigned integer", y) + x.mode = invalid + return + } + // rhs must be within reasonable bounds + const shiftBound = 1023 - 1 + 52 // so we can express smallestFloat64 + s, ok := constant.Uint64Val(yval) + if !ok || s > shiftBound { + check.invalidOp(y.pos(), "invalid shift count %s", y) + x.mode = invalid + return + } + // The lhs is representable as an integer but may not be an integer + // (e.g., 2.0, an untyped float) - this can only happen for untyped + // non-integer numeric constants. Correct the type so that the shift + // result is of integer type. + if !isInteger(x.typ) { + x.typ = Typ[UntypedInt] + } + // x is a constant so xval != nil and it must be of Int kind. + x.val = constant.Shift(xval, op, uint(s)) + // Typed constants must be representable in + // their type after each constant operation. + if isTyped(x.typ) { + if e != nil { + x.expr = e // for better error message + } + check.representable(x, x.typ.Underlying().(*Basic)) + } + return + } + + // non-constant shift with constant lhs + if untypedx { + // spec: "If the left operand of a non-constant shift + // expression is an untyped constant, the type of the + // constant is what it would be if the shift expression + // were replaced by its left operand alone.". + // + // Delay operand checking until we know the final type + // by marking the lhs expression as lhs shift operand. + // + // Usually (in correct programs), the lhs expression + // is in the untyped map. However, it is possible to + // create incorrect programs where the same expression + // is evaluated twice (via a declaration cycle) such + // that the lhs expression type is determined in the + // first round and thus deleted from the map, and then + // not found in the second round (double insertion of + // the same expr node still just leads to one entry for + // that node, and it can only be deleted once). + // Be cautious and check for presence of entry. + // Example: var e, f = int(1<<""[f]) // issue 11347 + if info, found := check.untyped[x.expr]; found { + info.isLhs = true + check.untyped[x.expr] = info + } + // keep x's type + x.mode = value + return + } + } + + // constant rhs must be >= 0 + if y.mode == constant_ && constant.Sign(y.val) < 0 { + check.invalidOp(y.pos(), "shift count %s must not be negative", y) + } + + // non-constant shift - lhs must be an integer + if !isInteger(x.typ) { + check.invalidOp(x.pos(), "shifted operand %s must be integer", x) + x.mode = invalid + return + } + + x.mode = value +} + +var binaryOpPredicates = opPredicates{ + token.ADD: func(typ Type) bool { return isNumeric(typ) || isString(typ) }, + token.SUB: isNumeric, + token.MUL: isNumeric, + token.QUO: isNumeric, + token.REM: isInteger, + + token.AND: isInteger, + token.OR: isInteger, + token.XOR: isInteger, + token.AND_NOT: isInteger, + + token.LAND: isBoolean, + token.LOR: isBoolean, +} + +// The binary expression e may be nil. It's passed in for better error messages only. +func (check *Checker) binary(x *operand, e *ast.BinaryExpr, lhs, rhs ast.Expr, op token.Token) { + var y operand + + check.expr(x, lhs) + check.expr(&y, rhs) + + if x.mode == invalid { + return + } + if y.mode == invalid { + x.mode = invalid + x.expr = y.expr + return + } + + if isShift(op) { + check.shift(x, &y, e, op) + return + } + + check.convertUntyped(x, y.typ) + if x.mode == invalid { + return + } + check.convertUntyped(&y, x.typ) + if y.mode == invalid { + x.mode = invalid + return + } + + if isComparison(op) { + check.comparison(x, &y, op) + return + } + + if !Identical(x.typ, y.typ) { + // only report an error if we have valid types + // (otherwise we had an error reported elsewhere already) + if x.typ != Typ[Invalid] && y.typ != Typ[Invalid] { + check.invalidOp(x.pos(), "mismatched types %s and %s", x.typ, y.typ) + } + x.mode = invalid + return + } + + if !check.op(binaryOpPredicates, x, op) { + x.mode = invalid + return + } + + if op == token.QUO || op == token.REM { + // check for zero divisor + if (x.mode == constant_ || isInteger(x.typ)) && y.mode == constant_ && constant.Sign(y.val) == 0 { + check.invalidOp(y.pos(), "division by zero") + x.mode = invalid + return + } + + // check for divisor underflow in complex division (see issue 20227) + if x.mode == constant_ && y.mode == constant_ && isComplex(x.typ) { + re, im := constant.Real(y.val), constant.Imag(y.val) + re2, im2 := constant.BinaryOp(re, token.MUL, re), constant.BinaryOp(im, token.MUL, im) + if constant.Sign(re2) == 0 && constant.Sign(im2) == 0 { + check.invalidOp(y.pos(), "division by zero") + x.mode = invalid + return + } + } + } + + if x.mode == constant_ && y.mode == constant_ { + xval := x.val + yval := y.val + typ := x.typ.Underlying().(*Basic) + // force integer division of integer operands + if op == token.QUO && isInteger(typ) { + op = token.QUO_ASSIGN + } + x.val = constant.BinaryOp(xval, op, yval) + // Typed constants must be representable in + // their type after each constant operation. + if isTyped(typ) { + if e != nil { + x.expr = e // for better error message + } + check.representable(x, typ) + } + return + } + + x.mode = value + // x.typ is unchanged +} + +// index checks an index expression for validity. +// If max >= 0, it is the upper bound for index. +// If index is valid and the result i >= 0, then i is the constant value of index. +func (check *Checker) index(index ast.Expr, max int64) (i int64, valid bool) { + var x operand + check.expr(&x, index) + if x.mode == invalid { + return + } + + // an untyped constant must be representable as Int + check.convertUntyped(&x, Typ[Int]) + if x.mode == invalid { + return + } + + // the index must be of integer type + if !isInteger(x.typ) { + check.invalidArg(x.pos(), "index %s must be integer", &x) + return + } + + // a constant index i must be in bounds + if x.mode == constant_ { + if constant.Sign(x.val) < 0 { + check.invalidArg(x.pos(), "index %s must not be negative", &x) + return + } + i, valid = constant.Int64Val(constant.ToInt(x.val)) + if !valid || max >= 0 && i >= max { + check.errorf(x.pos(), "index %s is out of bounds", &x) + return i, false + } + // 0 <= i [ && i < max ] + return i, true + } + + return -1, true +} + +// indexElts checks the elements (elts) of an array or slice composite literal +// against the literal's element type (typ), and the element indices against +// the literal length if known (length >= 0). It returns the length of the +// literal (maximum index value + 1). +// +func (check *Checker) indexedElts(elts []ast.Expr, typ Type, length int64) int64 { + visited := make(map[int64]bool, len(elts)) + var index, max int64 + for _, e := range elts { + // determine and check index + validIndex := false + eval := e + if kv, _ := e.(*ast.KeyValueExpr); kv != nil { + if i, ok := check.index(kv.Key, length); ok { + if i >= 0 { + index = i + validIndex = true + } else { + check.errorf(e.Pos(), "index %s must be integer constant", kv.Key) + } + } + eval = kv.Value + } else if length >= 0 && index >= length { + check.errorf(e.Pos(), "index %d is out of bounds (>= %d)", index, length) + } else { + validIndex = true + } + + // if we have a valid index, check for duplicate entries + if validIndex { + if visited[index] { + check.errorf(e.Pos(), "duplicate index %d in array or slice literal", index) + } + visited[index] = true + } + index++ + if index > max { + max = index + } + + // check element against composite literal element type + var x operand + check.exprWithHint(&x, eval, typ) + check.assignment(&x, typ, "array or slice literal") + } + return max +} + +// exprKind describes the kind of an expression; the kind +// determines if an expression is valid in 'statement context'. +type exprKind int + +const ( + conversion exprKind = iota + expression + statement +) + +// rawExpr typechecks expression e and initializes x with the expression +// value or type. If an error occurred, x.mode is set to invalid. +// If hint != nil, it is the type of a composite literal element. +// +func (check *Checker) rawExpr(x *operand, e ast.Expr, hint Type) exprKind { + if trace { + check.trace(e.Pos(), "%s", e) + check.indent++ + defer func() { + check.indent-- + check.trace(e.Pos(), "=> %s", x) + }() + } + + kind := check.exprInternal(x, e, hint) + + // convert x into a user-friendly set of values + // TODO(gri) this code can be simplified + var typ Type + var val constant.Value + switch x.mode { + case invalid: + typ = Typ[Invalid] + case novalue: + typ = (*Tuple)(nil) + case constant_: + typ = x.typ + val = x.val + default: + typ = x.typ + } + assert(x.expr != nil && typ != nil) + + if isUntyped(typ) { + // delay type and value recording until we know the type + // or until the end of type checking + check.rememberUntyped(x.expr, false, x.mode, typ.(*Basic), val) + } else { + check.recordTypeAndValue(e, x.mode, typ, val) + } + + return kind +} + +// exprInternal contains the core of type checking of expressions. +// Must only be called by rawExpr. +// +func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind { + // make sure x has a valid state in case of bailout + // (was issue 5770) + x.mode = invalid + x.typ = Typ[Invalid] + + switch e := e.(type) { + case *ast.BadExpr: + goto Error // error was reported before + + case *ast.Ident: + check.ident(x, e, nil, nil) + + case *ast.Ellipsis: + // ellipses are handled explicitly where they are legal + // (array composite literals and parameter lists) + check.error(e.Pos(), "invalid use of '...'") + goto Error + + case *ast.BasicLit: + x.setConst(e.Kind, e.Value) + if x.mode == invalid { + check.invalidAST(e.Pos(), "invalid literal %v", e.Value) + goto Error + } + + case *ast.FuncLit: + if sig, ok := check.typ(e.Type).(*Signature); ok { + // Anonymous functions are considered part of the + // init expression/func declaration which contains + // them: use existing package-level declaration info. + // + // TODO(gri) We delay type-checking of regular (top-level) + // function bodies until later. Why don't we do + // it for closures of top-level expressions? + // (We can't easily do it for local closures + // because the surrounding scopes must reflect + // the exact position where the closure appears + // in the source; e.g., variables declared below + // must not be visible). + check.funcBody(check.decl, "", sig, e.Body) + x.mode = value + x.typ = sig + } else { + check.invalidAST(e.Pos(), "invalid function literal %s", e) + goto Error + } + + case *ast.CompositeLit: + var typ, base Type + + switch { + case e.Type != nil: + // composite literal type present - use it + // [...]T array types may only appear with composite literals. + // Check for them here so we don't have to handle ... in general. + if atyp, _ := e.Type.(*ast.ArrayType); atyp != nil && atyp.Len != nil { + if ellip, _ := atyp.Len.(*ast.Ellipsis); ellip != nil && ellip.Elt == nil { + // We have an "open" [...]T array type. + // Create a new ArrayType with unknown length (-1) + // and finish setting it up after analyzing the literal. + typ = &Array{len: -1, elem: check.typ(atyp.Elt)} + base = typ + break + } + } + typ = check.typ(e.Type) + base = typ + + case hint != nil: + // no composite literal type present - use hint (element type of enclosing type) + typ = hint + base, _ = deref(typ.Underlying()) // *T implies &T{} + + default: + // TODO(gri) provide better error messages depending on context + check.error(e.Pos(), "missing type in composite literal") + goto Error + } + + switch utyp := base.Underlying().(type) { + case *Struct: + if len(e.Elts) == 0 { + break + } + fields := utyp.fields + if _, ok := e.Elts[0].(*ast.KeyValueExpr); ok { + // all elements must have keys + visited := make([]bool, len(fields)) + for _, e := range e.Elts { + kv, _ := e.(*ast.KeyValueExpr) + if kv == nil { + check.error(e.Pos(), "mixture of field:value and value elements in struct literal") + continue + } + key, _ := kv.Key.(*ast.Ident) + if key == nil { + check.errorf(kv.Pos(), "invalid field name %s in struct literal", kv.Key) + continue + } + i := fieldIndex(utyp.fields, check.pkg, key.Name) + if i < 0 { + check.errorf(kv.Pos(), "unknown field %s in struct literal", key.Name) + continue + } + fld := fields[i] + check.recordUse(key, fld) + // 0 <= i < len(fields) + if visited[i] { + check.errorf(kv.Pos(), "duplicate field name %s in struct literal", key.Name) + continue + } + visited[i] = true + check.expr(x, kv.Value) + etyp := fld.typ + check.assignment(x, etyp, "struct literal") + } + } else { + // no element must have a key + for i, e := range e.Elts { + if kv, _ := e.(*ast.KeyValueExpr); kv != nil { + check.error(kv.Pos(), "mixture of field:value and value elements in struct literal") + continue + } + check.expr(x, e) + if i >= len(fields) { + check.error(x.pos(), "too many values in struct literal") + break // cannot continue + } + // i < len(fields) + fld := fields[i] + if !fld.Exported() && fld.pkg != check.pkg { + check.errorf(x.pos(), "implicit assignment to unexported field %s in %s literal", fld.name, typ) + continue + } + etyp := fld.typ + check.assignment(x, etyp, "struct literal") + } + if len(e.Elts) < len(fields) { + check.error(e.Rbrace, "too few values in struct literal") + // ok to continue + } + } + + case *Array: + // Prevent crash if the array referred to is not yet set up. + // This is a stop-gap solution; a better approach would use the mechanism of + // Checker.ident (typexpr.go) using a path of types. But that would require + // passing the path everywhere (all expression-checking methods, not just + // type expression checking), and we're not set up for that (quite possibly + // an indication that cycle detection needs to be rethought). Was issue #18643. + if utyp.elem == nil { + check.error(e.Pos(), "illegal cycle in type declaration") + goto Error + } + n := check.indexedElts(e.Elts, utyp.elem, utyp.len) + // If we have an "open" [...]T array, set the length now that we know it + // and record the type for [...] (usually done by check.typExpr which is + // not called for [...]). + if utyp.len < 0 { + utyp.len = n + check.recordTypeAndValue(e.Type, typexpr, utyp, nil) + } + + case *Slice: + // Prevent crash if the slice referred to is not yet set up. + // See analogous comment for *Array. + if utyp.elem == nil { + check.error(e.Pos(), "illegal cycle in type declaration") + goto Error + } + check.indexedElts(e.Elts, utyp.elem, -1) + + case *Map: + // Prevent crash if the map referred to is not yet set up. + // See analogous comment for *Array. + if utyp.key == nil || utyp.elem == nil { + check.error(e.Pos(), "illegal cycle in type declaration") + goto Error + } + visited := make(map[interface{}][]Type, len(e.Elts)) + for _, e := range e.Elts { + kv, _ := e.(*ast.KeyValueExpr) + if kv == nil { + check.error(e.Pos(), "missing key in map literal") + continue + } + check.exprWithHint(x, kv.Key, utyp.key) + check.assignment(x, utyp.key, "map literal") + if x.mode == invalid { + continue + } + if x.mode == constant_ { + duplicate := false + // if the key is of interface type, the type is also significant when checking for duplicates + xkey := keyVal(x.val) + if _, ok := utyp.key.Underlying().(*Interface); ok { + for _, vtyp := range visited[xkey] { + if Identical(vtyp, x.typ) { + duplicate = true + break + } + } + visited[xkey] = append(visited[xkey], x.typ) + } else { + _, duplicate = visited[xkey] + visited[xkey] = nil + } + if duplicate { + check.errorf(x.pos(), "duplicate key %s in map literal", x.val) + continue + } + } + check.exprWithHint(x, kv.Value, utyp.elem) + check.assignment(x, utyp.elem, "map literal") + } + + default: + // when "using" all elements unpack KeyValueExpr + // explicitly because check.use doesn't accept them + for _, e := range e.Elts { + if kv, _ := e.(*ast.KeyValueExpr); kv != nil { + // Ideally, we should also "use" kv.Key but we can't know + // if it's an externally defined struct key or not. Going + // forward anyway can lead to other errors. Give up instead. + e = kv.Value + } + check.use(e) + } + // if utyp is invalid, an error was reported before + if utyp != Typ[Invalid] { + check.errorf(e.Pos(), "invalid composite literal type %s", typ) + goto Error + } + } + + x.mode = value + x.typ = typ + + case *ast.ParenExpr: + kind := check.rawExpr(x, e.X, nil) + x.expr = e + return kind + + case *ast.SelectorExpr: + check.selector(x, e) + + case *ast.IndexExpr: + check.expr(x, e.X) + if x.mode == invalid { + check.use(e.Index) + goto Error + } + + valid := false + length := int64(-1) // valid if >= 0 + switch typ := x.typ.Underlying().(type) { + case *Basic: + if isString(typ) { + valid = true + if x.mode == constant_ { + length = int64(len(constant.StringVal(x.val))) + } + // an indexed string always yields a byte value + // (not a constant) even if the string and the + // index are constant + x.mode = value + x.typ = universeByte // use 'byte' name + } + + case *Array: + valid = true + length = typ.len + if x.mode != variable { + x.mode = value + } + x.typ = typ.elem + + case *Pointer: + if typ, _ := typ.base.Underlying().(*Array); typ != nil { + valid = true + length = typ.len + x.mode = variable + x.typ = typ.elem + } + + case *Slice: + valid = true + x.mode = variable + x.typ = typ.elem + + case *Map: + var key operand + check.expr(&key, e.Index) + check.assignment(&key, typ.key, "map index") + if x.mode == invalid { + goto Error + } + x.mode = mapindex + x.typ = typ.elem + x.expr = e + return expression + } + + if !valid { + check.invalidOp(x.pos(), "cannot index %s", x) + goto Error + } + + if e.Index == nil { + check.invalidAST(e.Pos(), "missing index for %s", x) + goto Error + } + + check.index(e.Index, length) + // ok to continue + + case *ast.SliceExpr: + check.expr(x, e.X) + if x.mode == invalid { + check.use(e.Low, e.High, e.Max) + goto Error + } + + valid := false + length := int64(-1) // valid if >= 0 + switch typ := x.typ.Underlying().(type) { + case *Basic: + if isString(typ) { + if e.Slice3 { + check.invalidOp(x.pos(), "3-index slice of string") + goto Error + } + valid = true + if x.mode == constant_ { + length = int64(len(constant.StringVal(x.val))) + } + // spec: "For untyped string operands the result + // is a non-constant value of type string." + if typ.kind == UntypedString { + x.typ = Typ[String] + } + } + + case *Array: + valid = true + length = typ.len + if x.mode != variable { + check.invalidOp(x.pos(), "cannot slice %s (value not addressable)", x) + goto Error + } + x.typ = &Slice{elem: typ.elem} + + case *Pointer: + if typ, _ := typ.base.Underlying().(*Array); typ != nil { + valid = true + length = typ.len + x.typ = &Slice{elem: typ.elem} + } + + case *Slice: + valid = true + // x.typ doesn't change + } + + if !valid { + check.invalidOp(x.pos(), "cannot slice %s", x) + goto Error + } + + x.mode = value + + // spec: "Only the first index may be omitted; it defaults to 0." + if e.Slice3 && (e.High == nil || e.Max == nil) { + check.error(e.Rbrack, "2nd and 3rd index required in 3-index slice") + goto Error + } + + // check indices + var ind [3]int64 + for i, expr := range []ast.Expr{e.Low, e.High, e.Max} { + x := int64(-1) + switch { + case expr != nil: + // The "capacity" is only known statically for strings, arrays, + // and pointers to arrays, and it is the same as the length for + // those types. + max := int64(-1) + if length >= 0 { + max = length + 1 + } + if t, ok := check.index(expr, max); ok && t >= 0 { + x = t + } + case i == 0: + // default is 0 for the first index + x = 0 + case length >= 0: + // default is length (== capacity) otherwise + x = length + } + ind[i] = x + } + + // constant indices must be in range + // (check.index already checks that existing indices >= 0) + L: + for i, x := range ind[:len(ind)-1] { + if x > 0 { + for _, y := range ind[i+1:] { + if y >= 0 && x > y { + check.errorf(e.Rbrack, "invalid slice indices: %d > %d", x, y) + break L // only report one error, ok to continue + } + } + } + } + + case *ast.TypeAssertExpr: + check.expr(x, e.X) + if x.mode == invalid { + goto Error + } + xtyp, _ := x.typ.Underlying().(*Interface) + if xtyp == nil { + check.invalidOp(x.pos(), "%s is not an interface", x) + goto Error + } + // x.(type) expressions are handled explicitly in type switches + if e.Type == nil { + check.invalidAST(e.Pos(), "use of .(type) outside type switch") + goto Error + } + T := check.typ(e.Type) + if T == Typ[Invalid] { + goto Error + } + check.typeAssertion(x.pos(), x, xtyp, T) + x.mode = commaok + x.typ = T + + case *ast.CallExpr: + return check.call(x, e) + + case *ast.StarExpr: + check.exprOrType(x, e.X) + switch x.mode { + case invalid: + goto Error + case typexpr: + x.typ = &Pointer{base: x.typ} + default: + if typ, ok := x.typ.Underlying().(*Pointer); ok { + x.mode = variable + x.typ = typ.base + } else { + check.invalidOp(x.pos(), "cannot indirect %s", x) + goto Error + } + } + + case *ast.UnaryExpr: + check.expr(x, e.X) + if x.mode == invalid { + goto Error + } + check.unary(x, e, e.Op) + if x.mode == invalid { + goto Error + } + if e.Op == token.ARROW { + x.expr = e + return statement // receive operations may appear in statement context + } + + case *ast.BinaryExpr: + check.binary(x, e, e.X, e.Y, e.Op) + if x.mode == invalid { + goto Error + } + + case *ast.KeyValueExpr: + // key:value expressions are handled in composite literals + check.invalidAST(e.Pos(), "no key:value expected") + goto Error + + case *ast.ArrayType, *ast.StructType, *ast.FuncType, + *ast.InterfaceType, *ast.MapType, *ast.ChanType: + x.mode = typexpr + x.typ = check.typ(e) + // Note: rawExpr (caller of exprInternal) will call check.recordTypeAndValue + // even though check.typ has already called it. This is fine as both + // times the same expression and type are recorded. It is also not a + // performance issue because we only reach here for composite literal + // types, which are comparatively rare. + + default: + panic(fmt.Sprintf("%s: unknown expression type %T", check.fset.Position(e.Pos()), e)) + } + + // everything went well + x.expr = e + return expression + +Error: + x.mode = invalid + x.expr = e + return statement // avoid follow-up errors +} + +func keyVal(x constant.Value) interface{} { + switch x.Kind() { + case constant.Bool: + return constant.BoolVal(x) + case constant.String: + return constant.StringVal(x) + case constant.Int: + if v, ok := constant.Int64Val(x); ok { + return v + } + if v, ok := constant.Uint64Val(x); ok { + return v + } + case constant.Float: + v, _ := constant.Float64Val(x) + return v + case constant.Complex: + r, _ := constant.Float64Val(constant.Real(x)) + i, _ := constant.Float64Val(constant.Imag(x)) + return complex(r, i) + } + return x +} + +// typeAssertion checks that x.(T) is legal; xtyp must be the type of x. +func (check *Checker) typeAssertion(pos token.Pos, x *operand, xtyp *Interface, T Type) { + method, wrongType := assertableTo(xtyp, T) + if method == nil { + return + } + + var msg string + if wrongType { + msg = "wrong type for method" + } else { + msg = "missing method" + } + check.errorf(pos, "%s cannot have dynamic type %s (%s %s)", x, T, msg, method.name) +} + +func (check *Checker) singleValue(x *operand) { + if x.mode == value { + // tuple types are never named - no need for underlying type below + if t, ok := x.typ.(*Tuple); ok { + assert(t.Len() != 1) + check.errorf(x.pos(), "%d-valued %s where single value is expected", t.Len(), x) + x.mode = invalid + } + } +} + +// expr typechecks expression e and initializes x with the expression value. +// The result must be a single value. +// If an error occurred, x.mode is set to invalid. +// +func (check *Checker) expr(x *operand, e ast.Expr) { + check.multiExpr(x, e) + check.singleValue(x) +} + +// multiExpr is like expr but the result may be a multi-value. +func (check *Checker) multiExpr(x *operand, e ast.Expr) { + check.rawExpr(x, e, nil) + var msg string + switch x.mode { + default: + return + case novalue: + msg = "%s used as value" + case builtin: + msg = "%s must be called" + case typexpr: + msg = "%s is not an expression" + } + check.errorf(x.pos(), msg, x) + x.mode = invalid +} + +// exprWithHint typechecks expression e and initializes x with the expression value; +// hint is the type of a composite literal element. +// If an error occurred, x.mode is set to invalid. +// +func (check *Checker) exprWithHint(x *operand, e ast.Expr, hint Type) { + assert(hint != nil) + check.rawExpr(x, e, hint) + check.singleValue(x) + var msg string + switch x.mode { + default: + return + case novalue: + msg = "%s used as value" + case builtin: + msg = "%s must be called" + case typexpr: + msg = "%s is not an expression" + } + check.errorf(x.pos(), msg, x) + x.mode = invalid +} + +// exprOrType typechecks expression or type e and initializes x with the expression value or type. +// If an error occurred, x.mode is set to invalid. +// +func (check *Checker) exprOrType(x *operand, e ast.Expr) { + check.rawExpr(x, e, nil) + check.singleValue(x) + if x.mode == novalue { + check.errorf(x.pos(), "%s used as value or type", x) + x.mode = invalid + } +} diff --git a/third_party/forked/golang/go/types/exprstring.go b/third_party/forked/golang/go/types/exprstring.go new file mode 100644 index 00000000000..28d605f5ee8 --- /dev/null +++ b/third_party/forked/golang/go/types/exprstring.go @@ -0,0 +1,224 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements printing of expressions. + +package types + +import ( + "bytes" + "go/ast" +) + +// ExprString returns the (possibly shortened) string representation for x. +// Shortened representations are suitable for user interfaces but may not +// necessarily follow Go syntax. +func ExprString(x ast.Expr) string { + var buf bytes.Buffer + WriteExpr(&buf, x) + return buf.String() +} + +// WriteExpr writes the (possibly shortened) string representation for x to buf. +// Shortened representations are suitable for user interfaces but may not +// necessarily follow Go syntax. +func WriteExpr(buf *bytes.Buffer, x ast.Expr) { + // The AST preserves source-level parentheses so there is + // no need to introduce them here to correct for different + // operator precedences. (This assumes that the AST was + // generated by a Go parser.) + + switch x := x.(type) { + default: + buf.WriteString("(bad expr)") // nil, ast.BadExpr, ast.KeyValueExpr + + case *ast.Ident: + buf.WriteString(x.Name) + + case *ast.Ellipsis: + buf.WriteString("...") + if x.Elt != nil { + WriteExpr(buf, x.Elt) + } + + case *ast.BasicLit: + buf.WriteString(x.Value) + + case *ast.FuncLit: + buf.WriteByte('(') + WriteExpr(buf, x.Type) + buf.WriteString(" literal)") // shortened + + case *ast.CompositeLit: + buf.WriteByte('(') + WriteExpr(buf, x.Type) + buf.WriteString(" literal)") // shortened + + case *ast.ParenExpr: + buf.WriteByte('(') + WriteExpr(buf, x.X) + buf.WriteByte(')') + + case *ast.SelectorExpr: + WriteExpr(buf, x.X) + buf.WriteByte('.') + buf.WriteString(x.Sel.Name) + + case *ast.IndexExpr: + WriteExpr(buf, x.X) + buf.WriteByte('[') + WriteExpr(buf, x.Index) + buf.WriteByte(']') + + case *ast.SliceExpr: + WriteExpr(buf, x.X) + buf.WriteByte('[') + if x.Low != nil { + WriteExpr(buf, x.Low) + } + buf.WriteByte(':') + if x.High != nil { + WriteExpr(buf, x.High) + } + if x.Slice3 { + buf.WriteByte(':') + if x.Max != nil { + WriteExpr(buf, x.Max) + } + } + buf.WriteByte(']') + + case *ast.TypeAssertExpr: + WriteExpr(buf, x.X) + buf.WriteString(".(") + WriteExpr(buf, x.Type) + buf.WriteByte(')') + + case *ast.CallExpr: + WriteExpr(buf, x.Fun) + buf.WriteByte('(') + for i, arg := range x.Args { + if i > 0 { + buf.WriteString(", ") + } + WriteExpr(buf, arg) + } + if x.Ellipsis.IsValid() { + buf.WriteString("...") + } + buf.WriteByte(')') + + case *ast.StarExpr: + buf.WriteByte('*') + WriteExpr(buf, x.X) + + case *ast.UnaryExpr: + buf.WriteString(x.Op.String()) + WriteExpr(buf, x.X) + + case *ast.BinaryExpr: + WriteExpr(buf, x.X) + buf.WriteByte(' ') + buf.WriteString(x.Op.String()) + buf.WriteByte(' ') + WriteExpr(buf, x.Y) + + case *ast.ArrayType: + buf.WriteByte('[') + if x.Len != nil { + WriteExpr(buf, x.Len) + } + buf.WriteByte(']') + WriteExpr(buf, x.Elt) + + case *ast.StructType: + buf.WriteString("struct{") + writeFieldList(buf, x.Fields, "; ", false) + buf.WriteByte('}') + + case *ast.FuncType: + buf.WriteString("func") + writeSigExpr(buf, x) + + case *ast.InterfaceType: + buf.WriteString("interface{") + writeFieldList(buf, x.Methods, "; ", true) + buf.WriteByte('}') + + case *ast.MapType: + buf.WriteString("map[") + WriteExpr(buf, x.Key) + buf.WriteByte(']') + WriteExpr(buf, x.Value) + + case *ast.ChanType: + var s string + switch x.Dir { + case ast.SEND: + s = "chan<- " + case ast.RECV: + s = "<-chan " + default: + s = "chan " + } + buf.WriteString(s) + WriteExpr(buf, x.Value) + } +} + +func writeSigExpr(buf *bytes.Buffer, sig *ast.FuncType) { + buf.WriteByte('(') + writeFieldList(buf, sig.Params, ", ", false) + buf.WriteByte(')') + + res := sig.Results + n := res.NumFields() + if n == 0 { + // no result + return + } + + buf.WriteByte(' ') + if n == 1 && len(res.List[0].Names) == 0 { + // single unnamed result + WriteExpr(buf, res.List[0].Type) + return + } + + // multiple or named result(s) + buf.WriteByte('(') + writeFieldList(buf, res, ", ", false) + buf.WriteByte(')') +} + +func writeFieldList(buf *bytes.Buffer, fields *ast.FieldList, sep string, iface bool) { + for i, f := range fields.List { + if i > 0 { + buf.WriteString(sep) + } + + // field list names + for i, name := range f.Names { + if i > 0 { + buf.WriteString(", ") + } + buf.WriteString(name.Name) + } + + // types of interface methods consist of signatures only + if sig, _ := f.Type.(*ast.FuncType); sig != nil && iface { + writeSigExpr(buf, sig) + continue + } + + // named fields are separated with a blank from the field type + if len(f.Names) > 0 { + buf.WriteByte(' ') + } + + WriteExpr(buf, f.Type) + + // ignore tag + } +} diff --git a/third_party/forked/golang/go/types/gotype.go b/third_party/forked/golang/go/types/gotype.go new file mode 100644 index 00000000000..196fc9bbd60 --- /dev/null +++ b/third_party/forked/golang/go/types/gotype.go @@ -0,0 +1,332 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build ignore + +// Build this command explicitly: go build gotype.go + +/* +The gotype command, like the front-end of a Go compiler, parses and +type-checks a single Go package. Errors are reported if the analysis +fails; otherwise gotype is quiet (unless -v is set). + +Without a list of paths, gotype reads from standard input, which +must provide a single Go source file defining a complete package. + +With a single directory argument, gotype checks the Go files in +that directory, comprising a single package. Use -t to include the +(in-package) _test.go files. Use -x to type check only external +test files. + +Otherwise, each path must be the filename of a Go file belonging +to the same package. + +Imports are processed by importing directly from the source of +imported packages (default), or by importing from compiled and +installed packages (by setting -c to the respective compiler). + +The -c flag must be set to a compiler ("gc", "gccgo") when type- +checking packages containing imports with relative import paths +(import "./mypkg") because the source importer cannot know which +files to include for such packages. + +Usage: + gotype [flags] [path...] + +The flags are: + -t + include local test files in a directory (ignored if -x is provided) + -x + consider only external test files in a directory + -e + report all errors (not just the first 10) + -v + verbose mode + -c + compiler used for installed packages (gc, gccgo, or source); default: source + +Flags controlling additional output: + -ast + print AST (forces -seq) + -trace + print parse trace (forces -seq) + -comments + parse comments (ignored unless -ast or -trace is provided) + +Examples: + +To check the files a.go, b.go, and c.go: + + gotype a.go b.go c.go + +To check an entire package including (in-package) tests in the directory dir and print the processed files: + + gotype -t -v dir + +To check the external test package (if any) in the current directory, based on installed packages compiled with +cmd/compile: + + gotype -c=gc -x . + +To verify the output of a pipe: + + echo "package foo" | gotype + +*/ +package main + +import ( + "flag" + "fmt" + "go/ast" + "go/build" + "go/importer" + "go/parser" + "go/scanner" + "go/token" + "go/types" + "io/ioutil" + "os" + "path/filepath" + "sync" + "time" +) + +var ( + // main operation modes + testFiles = flag.Bool("t", false, "include in-package test files in a directory") + xtestFiles = flag.Bool("x", false, "consider only external test files in a directory") + allErrors = flag.Bool("e", false, "report all errors, not just the first 10") + verbose = flag.Bool("v", false, "verbose mode") + compiler = flag.String("c", "source", "compiler used for installed packages (gc, gccgo, or source)") + + // additional output control + printAST = flag.Bool("ast", false, "print AST (forces -seq)") + printTrace = flag.Bool("trace", false, "print parse trace (forces -seq)") + parseComments = flag.Bool("comments", false, "parse comments (ignored unless -ast or -trace is provided)") +) + +var ( + fset = token.NewFileSet() + errorCount = 0 + sequential = false + parserMode parser.Mode +) + +func initParserMode() { + if *allErrors { + parserMode |= parser.AllErrors + } + if *printAST { + sequential = true + } + if *printTrace { + parserMode |= parser.Trace + sequential = true + } + if *parseComments && (*printAST || *printTrace) { + parserMode |= parser.ParseComments + } +} + +const usageString = `usage: gotype [flags] [path ...] + +The gotype command, like the front-end of a Go compiler, parses and +type-checks a single Go package. Errors are reported if the analysis +fails; otherwise gotype is quiet (unless -v is set). + +Without a list of paths, gotype reads from standard input, which +must provide a single Go source file defining a complete package. + +With a single directory argument, gotype checks the Go files in +that directory, comprising a single package. Use -t to include the +(in-package) _test.go files. Use -x to type check only external +test files. + +Otherwise, each path must be the filename of a Go file belonging +to the same package. + +Imports are processed by importing directly from the source of +imported packages (default), or by importing from compiled and +installed packages (by setting -c to the respective compiler). + +The -c flag must be set to a compiler ("gc", "gccgo") when type- +checking packages containing imports with relative import paths +(import "./mypkg") because the source importer cannot know which +files to include for such packages. +` + +func usage() { + fmt.Fprintln(os.Stderr, usageString) + flag.PrintDefaults() + os.Exit(2) +} + +func report(err error) { + scanner.PrintError(os.Stderr, err) + if list, ok := err.(scanner.ErrorList); ok { + errorCount += len(list) + return + } + errorCount++ +} + +// parse may be called concurrently +func parse(filename string, src interface{}) (*ast.File, error) { + if *verbose { + fmt.Println(filename) + } + file, err := parser.ParseFile(fset, filename, src, parserMode) // ok to access fset concurrently + if *printAST { + ast.Print(fset, file) + } + return file, err +} + +func parseStdin() (*ast.File, error) { + src, err := ioutil.ReadAll(os.Stdin) + if err != nil { + return nil, err + } + return parse("", src) +} + +func parseFiles(dir string, filenames []string) ([]*ast.File, error) { + files := make([]*ast.File, len(filenames)) + errors := make([]error, len(filenames)) + + var wg sync.WaitGroup + for i, filename := range filenames { + wg.Add(1) + go func(i int, filepath string) { + defer wg.Done() + files[i], errors[i] = parse(filepath, nil) + }(i, filepath.Join(dir, filename)) + if sequential { + wg.Wait() + } + } + wg.Wait() + + // if there are errors, return the first one for deterministic results + for _, err := range errors { + if err != nil { + return nil, err + } + } + + return files, nil +} + +func parseDir(dir string) ([]*ast.File, error) { + ctxt := build.Default + pkginfo, err := ctxt.ImportDir(dir, 0) + if _, nogo := err.(*build.NoGoError); err != nil && !nogo { + return nil, err + } + + if *xtestFiles { + return parseFiles(dir, pkginfo.XTestGoFiles) + } + + filenames := append(pkginfo.GoFiles, pkginfo.CgoFiles...) + if *testFiles { + filenames = append(filenames, pkginfo.TestGoFiles...) + } + return parseFiles(dir, filenames) +} + +func getPkgFiles(args []string) ([]*ast.File, error) { + if len(args) == 0 { + // stdin + file, err := parseStdin() + if err != nil { + return nil, err + } + return []*ast.File{file}, nil + } + + if len(args) == 1 { + // possibly a directory + path := args[0] + info, err := os.Stat(path) + if err != nil { + return nil, err + } + if info.IsDir() { + return parseDir(path) + } + } + + // list of files + return parseFiles("", args) +} + +func checkPkgFiles(files []*ast.File) { + type bailout struct{} + + // if checkPkgFiles is called multiple times, set up conf only once + conf := types.Config{ + FakeImportC: true, + Error: func(err error) { + if !*allErrors && errorCount >= 10 { + panic(bailout{}) + } + report(err) + }, + Importer: importer.For(*compiler, nil), + Sizes: types.SizesFor(build.Default.Compiler, build.Default.GOARCH), + } + + defer func() { + switch p := recover().(type) { + case nil, bailout: + // normal return or early exit + default: + // re-panic + panic(p) + } + }() + + const path = "pkg" // any non-empty string will do for now + conf.Check(path, fset, files, nil) +} + +func printStats(d time.Duration) { + fileCount := 0 + lineCount := 0 + fset.Iterate(func(f *token.File) bool { + fileCount++ + lineCount += f.LineCount() + return true + }) + + fmt.Printf( + "%s (%d files, %d lines, %d lines/s)\n", + d, fileCount, lineCount, int64(float64(lineCount)/d.Seconds()), + ) +} + +func main() { + flag.Usage = usage + flag.Parse() + initParserMode() + + start := time.Now() + + files, err := getPkgFiles(flag.Args()) + if err != nil { + report(err) + os.Exit(2) + } + + checkPkgFiles(files) + if errorCount > 0 { + os.Exit(2) + } + + if *verbose { + printStats(time.Since(start)) + } +} diff --git a/third_party/forked/golang/go/types/initorder.go b/third_party/forked/golang/go/types/initorder.go new file mode 100644 index 00000000000..966dccb8289 --- /dev/null +++ b/third_party/forked/golang/go/types/initorder.go @@ -0,0 +1,297 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package types + +import ( + "container/heap" + "fmt" +) + +// initOrder computes the Info.InitOrder for package variables. +func (check *Checker) initOrder() { + // An InitOrder may already have been computed if a package is + // built from several calls to (*Checker).Files. Clear it. + check.Info.InitOrder = check.Info.InitOrder[:0] + + // Compute the object dependency graph and initialize + // a priority queue with the list of graph nodes. + pq := nodeQueue(dependencyGraph(check.objMap)) + heap.Init(&pq) + + const debug = false + if debug { + fmt.Printf("Computing initialization order for %s\n\n", check.pkg) + fmt.Println("Object dependency graph:") + for obj, d := range check.objMap { + // only print objects that may appear in the dependency graph + if obj, _ := obj.(dependency); obj != nil { + if len(d.deps) > 0 { + fmt.Printf("\t%s depends on\n", obj.Name()) + for dep := range d.deps { + fmt.Printf("\t\t%s\n", dep.Name()) + } + } else { + fmt.Printf("\t%s has no dependencies\n", obj.Name()) + } + } + } + fmt.Println() + + fmt.Println("Transposed object dependency graph (functions eliminated):") + for _, n := range pq { + fmt.Printf("\t%s depends on %d nodes\n", n.obj.Name(), n.ndeps) + for p := range n.pred { + fmt.Printf("\t\t%s is dependent\n", p.obj.Name()) + } + } + fmt.Println() + + fmt.Println("Processing nodes:") + } + + // Determine initialization order by removing the highest priority node + // (the one with the fewest dependencies) and its edges from the graph, + // repeatedly, until there are no nodes left. + // In a valid Go program, those nodes always have zero dependencies (after + // removing all incoming dependencies), otherwise there are initialization + // cycles. + emitted := make(map[*declInfo]bool) + for len(pq) > 0 { + // get the next node + n := heap.Pop(&pq).(*graphNode) + + if debug { + fmt.Printf("\t%s (src pos %d) depends on %d nodes now\n", + n.obj.Name(), n.obj.order(), n.ndeps) + } + + // if n still depends on other nodes, we have a cycle + if n.ndeps > 0 { + cycle := findPath(check.objMap, n.obj, n.obj, make(objSet)) + // If n.obj is not part of the cycle (e.g., n.obj->b->c->d->c), + // cycle will be nil. Don't report anything in that case since + // the cycle is reported when the algorithm gets to an object + // in the cycle. + // Furthermore, once an object in the cycle is encountered, + // the cycle will be broken (dependency count will be reduced + // below), and so the remaining nodes in the cycle don't trigger + // another error (unless they are part of multiple cycles). + if cycle != nil { + check.reportCycle(cycle) + } + // Ok to continue, but the variable initialization order + // will be incorrect at this point since it assumes no + // cycle errors. + } + + // reduce dependency count of all dependent nodes + // and update priority queue + for p := range n.pred { + p.ndeps-- + heap.Fix(&pq, p.index) + } + + // record the init order for variables with initializers only + v, _ := n.obj.(*Var) + info := check.objMap[v] + if v == nil || !info.hasInitializer() { + continue + } + + // n:1 variable declarations such as: a, b = f() + // introduce a node for each lhs variable (here: a, b); + // but they all have the same initializer - emit only + // one, for the first variable seen + if emitted[info] { + continue // initializer already emitted, if any + } + emitted[info] = true + + infoLhs := info.lhs // possibly nil (see declInfo.lhs field comment) + if infoLhs == nil { + infoLhs = []*Var{v} + } + init := &Initializer{infoLhs, info.init} + check.Info.InitOrder = append(check.Info.InitOrder, init) + } + + if debug { + fmt.Println() + fmt.Println("Initialization order:") + for _, init := range check.Info.InitOrder { + fmt.Printf("\t%s\n", init) + } + fmt.Println() + } +} + +// findPath returns the (reversed) list of objects []Object{to, ... from} +// such that there is a path of object dependencies from 'from' to 'to'. +// If there is no such path, the result is nil. +func findPath(objMap map[Object]*declInfo, from, to Object, visited objSet) []Object { + if visited[from] { + return nil // node already seen + } + visited[from] = true + + for d := range objMap[from].deps { + if d == to { + return []Object{d} + } + if P := findPath(objMap, d, to, visited); P != nil { + return append(P, d) + } + } + + return nil +} + +// reportCycle reports an error for the given cycle. +func (check *Checker) reportCycle(cycle []Object) { + obj := cycle[0] + check.errorf(obj.Pos(), "initialization cycle for %s", obj.Name()) + // subtle loop: print cycle[i] for i = 0, n-1, n-2, ... 1 for len(cycle) = n + for i := len(cycle) - 1; i >= 0; i-- { + check.errorf(obj.Pos(), "\t%s refers to", obj.Name()) // secondary error, \t indented + obj = cycle[i] + } + // print cycle[0] again to close the cycle + check.errorf(obj.Pos(), "\t%s", obj.Name()) +} + +// ---------------------------------------------------------------------------- +// Object dependency graph + +// A dependency is an object that may be a dependency in an initialization +// expression. Only constants, variables, and functions can be dependencies. +// Constants are here because constant expression cycles are reported during +// initialization order computation. +type dependency interface { + Object + isDependency() +} + +// A graphNode represents a node in the object dependency graph. +// Each node p in n.pred represents an edge p->n, and each node +// s in n.succ represents an edge n->s; with a->b indicating that +// a depends on b. +type graphNode struct { + obj dependency // object represented by this node + pred, succ nodeSet // consumers and dependencies of this node (lazily initialized) + index int // node index in graph slice/priority queue + ndeps int // number of outstanding dependencies before this object can be initialized +} + +type nodeSet map[*graphNode]bool + +func (s *nodeSet) add(p *graphNode) { + if *s == nil { + *s = make(nodeSet) + } + (*s)[p] = true +} + +// dependencyGraph computes the object dependency graph from the given objMap, +// with any function nodes removed. The resulting graph contains only constants +// and variables. +func dependencyGraph(objMap map[Object]*declInfo) []*graphNode { + // M is the dependency (Object) -> graphNode mapping + M := make(map[dependency]*graphNode) + for obj := range objMap { + // only consider nodes that may be an initialization dependency + if obj, _ := obj.(dependency); obj != nil { + M[obj] = &graphNode{obj: obj} + } + } + + // compute edges for graph M + // (We need to include all nodes, even isolated ones, because they still need + // to be scheduled for initialization in correct order relative to other nodes.) + for obj, n := range M { + // for each dependency obj -> d (= deps[i]), create graph edges n->s and s->n + for d := range objMap[obj].deps { + // only consider nodes that may be an initialization dependency + if d, _ := d.(dependency); d != nil { + d := M[d] + n.succ.add(d) + d.pred.add(n) + } + } + } + + // remove function nodes and collect remaining graph nodes in G + // (Mutually recursive functions may introduce cycles among themselves + // which are permitted. Yet such cycles may incorrectly inflate the dependency + // count for variables which in turn may not get scheduled for initialization + // in correct order.) + var G []*graphNode + for obj, n := range M { + if _, ok := obj.(*Func); ok { + // connect each predecessor p of n with each successor s + // and drop the function node (don't collect it in G) + for p := range n.pred { + // ignore self-cycles + if p != n { + // Each successor s of n becomes a successor of p, and + // each predecessor p of n becomes a predecessor of s. + for s := range n.succ { + // ignore self-cycles + if s != n { + p.succ.add(s) + s.pred.add(p) + delete(s.pred, n) // remove edge to n + } + } + delete(p.succ, n) // remove edge to n + } + } + } else { + // collect non-function nodes + G = append(G, n) + } + } + + // fill in index and ndeps fields + for i, n := range G { + n.index = i + n.ndeps = len(n.succ) + } + + return G +} + +// ---------------------------------------------------------------------------- +// Priority queue + +// nodeQueue implements the container/heap interface; +// a nodeQueue may be used as a priority queue. +type nodeQueue []*graphNode + +func (a nodeQueue) Len() int { return len(a) } + +func (a nodeQueue) Swap(i, j int) { + x, y := a[i], a[j] + a[i], a[j] = y, x + x.index, y.index = j, i +} + +func (a nodeQueue) Less(i, j int) bool { + x, y := a[i], a[j] + // nodes are prioritized by number of incoming dependencies (1st key) + // and source order (2nd key) + return x.ndeps < y.ndeps || x.ndeps == y.ndeps && x.obj.order() < y.obj.order() +} + +func (a *nodeQueue) Push(x interface{}) { + panic("unreachable") +} + +func (a *nodeQueue) Pop() interface{} { + n := len(*a) + x := (*a)[n-1] + x.index = -1 // for safety + *a = (*a)[:n-1] + return x +} diff --git a/third_party/forked/golang/go/types/labels.go b/third_party/forked/golang/go/types/labels.go new file mode 100644 index 00000000000..3b43b4ba05c --- /dev/null +++ b/third_party/forked/golang/go/types/labels.go @@ -0,0 +1,268 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package types + +import ( + "go/ast" + "go/token" +) + +// labels checks correct label use in body. +func (check *Checker) labels(body *ast.BlockStmt) { + // set of all labels in this body + all := NewScope(nil, body.Pos(), body.End(), "label") + + fwdJumps := check.blockBranches(all, nil, nil, body.List) + + // If there are any forward jumps left, no label was found for + // the corresponding goto statements. Either those labels were + // never defined, or they are inside blocks and not reachable + // for the respective gotos. + for _, jmp := range fwdJumps { + var msg string + name := jmp.Label.Name + if alt := all.Lookup(name); alt != nil { + msg = "goto %s jumps into block" + alt.(*Label).used = true // avoid another error + } else { + msg = "label %s not declared" + } + check.errorf(jmp.Label.Pos(), msg, name) + } + + // spec: "It is illegal to define a label that is never used." + for _, obj := range all.elems { + if lbl := obj.(*Label); !lbl.used { + check.softErrorf(lbl.pos, "label %s declared but not used", lbl.name) + } + } +} + +// A block tracks label declarations in a block and its enclosing blocks. +type block struct { + parent *block // enclosing block + lstmt *ast.LabeledStmt // labeled statement to which this block belongs, or nil + labels map[string]*ast.LabeledStmt // allocated lazily +} + +// insert records a new label declaration for the current block. +// The label must not have been declared before in any block. +func (b *block) insert(s *ast.LabeledStmt) { + name := s.Label.Name + if debug { + assert(b.gotoTarget(name) == nil) + } + labels := b.labels + if labels == nil { + labels = make(map[string]*ast.LabeledStmt) + b.labels = labels + } + labels[name] = s +} + +// gotoTarget returns the labeled statement in the current +// or an enclosing block with the given label name, or nil. +func (b *block) gotoTarget(name string) *ast.LabeledStmt { + for s := b; s != nil; s = s.parent { + if t := s.labels[name]; t != nil { + return t + } + } + return nil +} + +// enclosingTarget returns the innermost enclosing labeled +// statement with the given label name, or nil. +func (b *block) enclosingTarget(name string) *ast.LabeledStmt { + for s := b; s != nil; s = s.parent { + if t := s.lstmt; t != nil && t.Label.Name == name { + return t + } + } + return nil +} + +// blockBranches processes a block's statement list and returns the set of outgoing forward jumps. +// all is the scope of all declared labels, parent the set of labels declared in the immediately +// enclosing block, and lstmt is the labeled statement this block is associated with (or nil). +func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *ast.LabeledStmt, list []ast.Stmt) []*ast.BranchStmt { + b := &block{parent: parent, lstmt: lstmt} + + var ( + varDeclPos token.Pos + fwdJumps, badJumps []*ast.BranchStmt + ) + + // All forward jumps jumping over a variable declaration are possibly + // invalid (they may still jump out of the block and be ok). + // recordVarDecl records them for the given position. + recordVarDecl := func(pos token.Pos) { + varDeclPos = pos + badJumps = append(badJumps[:0], fwdJumps...) // copy fwdJumps to badJumps + } + + jumpsOverVarDecl := func(jmp *ast.BranchStmt) bool { + if varDeclPos.IsValid() { + for _, bad := range badJumps { + if jmp == bad { + return true + } + } + } + return false + } + + blockBranches := func(lstmt *ast.LabeledStmt, list []ast.Stmt) { + // Unresolved forward jumps inside the nested block + // become forward jumps in the current block. + fwdJumps = append(fwdJumps, check.blockBranches(all, b, lstmt, list)...) + } + + var stmtBranches func(ast.Stmt) + stmtBranches = func(s ast.Stmt) { + switch s := s.(type) { + case *ast.DeclStmt: + if d, _ := s.Decl.(*ast.GenDecl); d != nil && d.Tok == token.VAR { + recordVarDecl(d.Pos()) + } + + case *ast.LabeledStmt: + // declare non-blank label + if name := s.Label.Name; name != "_" { + lbl := NewLabel(s.Label.Pos(), check.pkg, name) + if alt := all.Insert(lbl); alt != nil { + check.softErrorf(lbl.pos, "label %s already declared", name) + check.reportAltDecl(alt) + // ok to continue + } else { + b.insert(s) + check.recordDef(s.Label, lbl) + } + // resolve matching forward jumps and remove them from fwdJumps + i := 0 + for _, jmp := range fwdJumps { + if jmp.Label.Name == name { + // match + lbl.used = true + check.recordUse(jmp.Label, lbl) + if jumpsOverVarDecl(jmp) { + check.softErrorf( + jmp.Label.Pos(), + "goto %s jumps over variable declaration at line %d", + name, + check.fset.Position(varDeclPos).Line, + ) + // ok to continue + } + } else { + // no match - record new forward jump + fwdJumps[i] = jmp + i++ + } + } + fwdJumps = fwdJumps[:i] + lstmt = s + } + stmtBranches(s.Stmt) + + case *ast.BranchStmt: + if s.Label == nil { + return // checked in 1st pass (check.stmt) + } + + // determine and validate target + name := s.Label.Name + switch s.Tok { + case token.BREAK: + // spec: "If there is a label, it must be that of an enclosing + // "for", "switch", or "select" statement, and that is the one + // whose execution terminates." + valid := false + if t := b.enclosingTarget(name); t != nil { + switch t.Stmt.(type) { + case *ast.SwitchStmt, *ast.TypeSwitchStmt, *ast.SelectStmt, *ast.ForStmt, *ast.RangeStmt: + valid = true + } + } + if !valid { + check.errorf(s.Label.Pos(), "invalid break label %s", name) + return + } + + case token.CONTINUE: + // spec: "If there is a label, it must be that of an enclosing + // "for" statement, and that is the one whose execution advances." + valid := false + if t := b.enclosingTarget(name); t != nil { + switch t.Stmt.(type) { + case *ast.ForStmt, *ast.RangeStmt: + valid = true + } + } + if !valid { + check.errorf(s.Label.Pos(), "invalid continue label %s", name) + return + } + + case token.GOTO: + if b.gotoTarget(name) == nil { + // label may be declared later - add branch to forward jumps + fwdJumps = append(fwdJumps, s) + return + } + + default: + check.invalidAST(s.Pos(), "branch statement: %s %s", s.Tok, name) + return + } + + // record label use + obj := all.Lookup(name) + obj.(*Label).used = true + check.recordUse(s.Label, obj) + + case *ast.AssignStmt: + if s.Tok == token.DEFINE { + recordVarDecl(s.Pos()) + } + + case *ast.BlockStmt: + blockBranches(lstmt, s.List) + + case *ast.IfStmt: + stmtBranches(s.Body) + if s.Else != nil { + stmtBranches(s.Else) + } + + case *ast.CaseClause: + blockBranches(nil, s.Body) + + case *ast.SwitchStmt: + stmtBranches(s.Body) + + case *ast.TypeSwitchStmt: + stmtBranches(s.Body) + + case *ast.CommClause: + blockBranches(nil, s.Body) + + case *ast.SelectStmt: + stmtBranches(s.Body) + + case *ast.ForStmt: + stmtBranches(s.Body) + + case *ast.RangeStmt: + stmtBranches(s.Body) + } + } + + for _, s := range list { + stmtBranches(s) + } + + return fwdJumps +} diff --git a/third_party/forked/golang/go/types/lookup.go b/third_party/forked/golang/go/types/lookup.go new file mode 100644 index 00000000000..ee8202d9e42 --- /dev/null +++ b/third_party/forked/golang/go/types/lookup.go @@ -0,0 +1,354 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements various field and method lookup functions. + +package types + +// LookupFieldOrMethod looks up a field or method with given package and name +// in T and returns the corresponding *Var or *Func, an index sequence, and a +// bool indicating if there were any pointer indirections on the path to the +// field or method. If addressable is set, T is the type of an addressable +// variable (only matters for method lookups). +// +// The last index entry is the field or method index in the (possibly embedded) +// type where the entry was found, either: +// +// 1) the list of declared methods of a named type; or +// 2) the list of all methods (method set) of an interface type; or +// 3) the list of fields of a struct type. +// +// The earlier index entries are the indices of the anonymous struct fields +// traversed to get to the found entry, starting at depth 0. +// +// If no entry is found, a nil object is returned. In this case, the returned +// index and indirect values have the following meaning: +// +// - If index != nil, the index sequence points to an ambiguous entry +// (the same name appeared more than once at the same embedding level). +// +// - If indirect is set, a method with a pointer receiver type was found +// but there was no pointer on the path from the actual receiver type to +// the method's formal receiver base type, nor was the receiver addressable. +// +func LookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) { + // Methods cannot be associated to a named pointer type + // (spec: "The type denoted by T is called the receiver base type; + // it must not be a pointer or interface type and it must be declared + // in the same package as the method."). + // Thus, if we have a named pointer type, proceed with the underlying + // pointer type but discard the result if it is a method since we would + // not have found it for T (see also issue 8590). + if t, _ := T.(*Named); t != nil { + if p, _ := t.underlying.(*Pointer); p != nil { + obj, index, indirect = lookupFieldOrMethod(p, false, pkg, name) + if _, ok := obj.(*Func); ok { + return nil, nil, false + } + return + } + } + + return lookupFieldOrMethod(T, addressable, pkg, name) +} + +// TODO(gri) The named type consolidation and seen maps below must be +// indexed by unique keys for a given type. Verify that named +// types always have only one representation (even when imported +// indirectly via different packages.) + +func lookupFieldOrMethod(T Type, addressable bool, pkg *Package, name string) (obj Object, index []int, indirect bool) { + // WARNING: The code in this function is extremely subtle - do not modify casually! + // This function and NewMethodSet should be kept in sync. + + if name == "_" { + return // blank fields/methods are never found + } + + typ, isPtr := deref(T) + + // *typ where typ is an interface has no methods. + if isPtr && IsInterface(typ) { + return + } + + // Start with typ as single entry at shallowest depth. + current := []embeddedType{{typ, nil, isPtr, false}} + + // Named types that we have seen already, allocated lazily. + // Used to avoid endless searches in case of recursive types. + // Since only Named types can be used for recursive types, we + // only need to track those. + // (If we ever allow type aliases to construct recursive types, + // we must use type identity rather than pointer equality for + // the map key comparison, as we do in consolidateMultiples.) + var seen map[*Named]bool + + // search current depth + for len(current) > 0 { + var next []embeddedType // embedded types found at current depth + + // look for (pkg, name) in all types at current depth + for _, e := range current { + typ := e.typ + + // If we have a named type, we may have associated methods. + // Look for those first. + if named, _ := typ.(*Named); named != nil { + if seen[named] { + // We have seen this type before, at a more shallow depth + // (note that multiples of this type at the current depth + // were consolidated before). The type at that depth shadows + // this same type at the current depth, so we can ignore + // this one. + continue + } + if seen == nil { + seen = make(map[*Named]bool) + } + seen[named] = true + + // look for a matching attached method + if i, m := lookupMethod(named.methods, pkg, name); m != nil { + // potential match + assert(m.typ != nil) + index = concat(e.index, i) + if obj != nil || e.multiples { + return nil, index, false // collision + } + obj = m + indirect = e.indirect + continue // we can't have a matching field or interface method + } + + // continue with underlying type + typ = named.underlying + } + + switch t := typ.(type) { + case *Struct: + // look for a matching field and collect embedded types + for i, f := range t.fields { + if f.sameId(pkg, name) { + assert(f.typ != nil) + index = concat(e.index, i) + if obj != nil || e.multiples { + return nil, index, false // collision + } + obj = f + indirect = e.indirect + continue // we can't have a matching interface method + } + // Collect embedded struct fields for searching the next + // lower depth, but only if we have not seen a match yet + // (if we have a match it is either the desired field or + // we have a name collision on the same depth; in either + // case we don't need to look further). + // Embedded fields are always of the form T or *T where + // T is a type name. If e.typ appeared multiple times at + // this depth, f.typ appears multiple times at the next + // depth. + if obj == nil && f.anonymous { + typ, isPtr := deref(f.typ) + // TODO(gri) optimization: ignore types that can't + // have fields or methods (only Named, Struct, and + // Interface types need to be considered). + next = append(next, embeddedType{typ, concat(e.index, i), e.indirect || isPtr, e.multiples}) + } + } + + case *Interface: + // look for a matching method + // TODO(gri) t.allMethods is sorted - use binary search + if i, m := lookupMethod(t.allMethods, pkg, name); m != nil { + assert(m.typ != nil) + index = concat(e.index, i) + if obj != nil || e.multiples { + return nil, index, false // collision + } + obj = m + indirect = e.indirect + } + } + } + + if obj != nil { + // found a potential match + // spec: "A method call x.m() is valid if the method set of (the type of) x + // contains m and the argument list can be assigned to the parameter + // list of m. If x is addressable and &x's method set contains m, x.m() + // is shorthand for (&x).m()". + if f, _ := obj.(*Func); f != nil && ptrRecv(f) && !indirect && !addressable { + return nil, nil, true // pointer/addressable receiver required + } + return + } + + current = consolidateMultiples(next) + } + + return nil, nil, false // not found +} + +// embeddedType represents an embedded type +type embeddedType struct { + typ Type + index []int // embedded field indices, starting with index at depth 0 + indirect bool // if set, there was a pointer indirection on the path to this field + multiples bool // if set, typ appears multiple times at this depth +} + +// consolidateMultiples collects multiple list entries with the same type +// into a single entry marked as containing multiples. The result is the +// consolidated list. +func consolidateMultiples(list []embeddedType) []embeddedType { + if len(list) <= 1 { + return list // at most one entry - nothing to do + } + + n := 0 // number of entries w/ unique type + prev := make(map[Type]int) // index at which type was previously seen + for _, e := range list { + if i, found := lookupType(prev, e.typ); found { + list[i].multiples = true + // ignore this entry + } else { + prev[e.typ] = n + list[n] = e + n++ + } + } + return list[:n] +} + +func lookupType(m map[Type]int, typ Type) (int, bool) { + // fast path: maybe the types are equal + if i, found := m[typ]; found { + return i, true + } + + for t, i := range m { + if Identical(t, typ) { + return i, true + } + } + + return 0, false +} + +// MissingMethod returns (nil, false) if V implements T, otherwise it +// returns a missing method required by T and whether it is missing or +// just has the wrong type. +// +// For non-interface types V, or if static is set, V implements T if all +// methods of T are present in V. Otherwise (V is an interface and static +// is not set), MissingMethod only checks that methods of T which are also +// present in V have matching types (e.g., for a type assertion x.(T) where +// x is of interface type V). +// +func MissingMethod(V Type, T *Interface, static bool) (method *Func, wrongType bool) { + // fast path for common case + if T.Empty() { + return + } + + // TODO(gri) Consider using method sets here. Might be more efficient. + + if ityp, _ := V.Underlying().(*Interface); ityp != nil { + // TODO(gri) allMethods is sorted - can do this more efficiently + for _, m := range T.allMethods { + _, obj := lookupMethod(ityp.allMethods, m.pkg, m.name) + switch { + case obj == nil: + if static { + return m, false + } + case !Identical(obj.Type(), m.typ): + return m, true + } + } + return + } + + // A concrete type implements T if it implements all methods of T. + for _, m := range T.allMethods { + obj, _, _ := lookupFieldOrMethod(V, false, m.pkg, m.name) + + f, _ := obj.(*Func) + if f == nil { + return m, false + } + + if !Identical(f.typ, m.typ) { + return m, true + } + } + + return +} + +// assertableTo reports whether a value of type V can be asserted to have type T. +// It returns (nil, false) as affirmative answer. Otherwise it returns a missing +// method required by V and whether it is missing or just has the wrong type. +func assertableTo(V *Interface, T Type) (method *Func, wrongType bool) { + // no static check is required if T is an interface + // spec: "If T is an interface type, x.(T) asserts that the + // dynamic type of x implements the interface T." + if _, ok := T.Underlying().(*Interface); ok && !strict { + return + } + return MissingMethod(T, V, false) +} + +// deref dereferences typ if it is a *Pointer and returns its base and true. +// Otherwise it returns (typ, false). +func deref(typ Type) (Type, bool) { + if p, _ := typ.(*Pointer); p != nil { + return p.base, true + } + return typ, false +} + +// derefStructPtr dereferences typ if it is a (named or unnamed) pointer to a +// (named or unnamed) struct and returns its base. Otherwise it returns typ. +func derefStructPtr(typ Type) Type { + if p, _ := typ.Underlying().(*Pointer); p != nil { + if _, ok := p.base.Underlying().(*Struct); ok { + return p.base + } + } + return typ +} + +// concat returns the result of concatenating list and i. +// The result does not share its underlying array with list. +func concat(list []int, i int) []int { + var t []int + t = append(t, list...) + return append(t, i) +} + +// fieldIndex returns the index for the field with matching package and name, or a value < 0. +func fieldIndex(fields []*Var, pkg *Package, name string) int { + if name != "_" { + for i, f := range fields { + if f.sameId(pkg, name) { + return i + } + } + } + return -1 +} + +// lookupMethod returns the index of and method with matching package and name, or (-1, nil). +func lookupMethod(methods []*Func, pkg *Package, name string) (int, *Func) { + if name != "_" { + for i, m := range methods { + if m.sameId(pkg, name) { + return i, m + } + } + } + return -1, nil +} diff --git a/third_party/forked/golang/go/types/methodset.go b/third_party/forked/golang/go/types/methodset.go new file mode 100644 index 00000000000..2a8b1c24f7a --- /dev/null +++ b/third_party/forked/golang/go/types/methodset.go @@ -0,0 +1,262 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements method sets. + +package types + +import ( + "bytes" + "fmt" + "sort" +) + +// A MethodSet is an ordered set of concrete or abstract (interface) methods; +// a method is a MethodVal selection, and they are ordered by ascending m.Obj().Id(). +// The zero value for a MethodSet is a ready-to-use empty method set. +type MethodSet struct { + list []*Selection +} + +func (s *MethodSet) String() string { + if s.Len() == 0 { + return "MethodSet {}" + } + + var buf bytes.Buffer + fmt.Fprintln(&buf, "MethodSet {") + for _, f := range s.list { + fmt.Fprintf(&buf, "\t%s\n", f) + } + fmt.Fprintln(&buf, "}") + return buf.String() +} + +// Len returns the number of methods in s. +func (s *MethodSet) Len() int { return len(s.list) } + +// At returns the i'th method in s for 0 <= i < s.Len(). +func (s *MethodSet) At(i int) *Selection { return s.list[i] } + +// Lookup returns the method with matching package and name, or nil if not found. +func (s *MethodSet) Lookup(pkg *Package, name string) *Selection { + if s.Len() == 0 { + return nil + } + + key := Id(pkg, name) + i := sort.Search(len(s.list), func(i int) bool { + m := s.list[i] + return m.obj.Id() >= key + }) + if i < len(s.list) { + m := s.list[i] + if m.obj.Id() == key { + return m + } + } + return nil +} + +// Shared empty method set. +var emptyMethodSet MethodSet + +// NewMethodSet returns the method set for the given type T. +// It always returns a non-nil method set, even if it is empty. +func NewMethodSet(T Type) *MethodSet { + // WARNING: The code in this function is extremely subtle - do not modify casually! + // This function and lookupFieldOrMethod should be kept in sync. + + // method set up to the current depth, allocated lazily + var base methodSet + + typ, isPtr := deref(T) + + // *typ where typ is an interface has no methods. + if isPtr && IsInterface(typ) { + return &emptyMethodSet + } + + // Start with typ as single entry at shallowest depth. + current := []embeddedType{{typ, nil, isPtr, false}} + + // Named types that we have seen already, allocated lazily. + // Used to avoid endless searches in case of recursive types. + // Since only Named types can be used for recursive types, we + // only need to track those. + // (If we ever allow type aliases to construct recursive types, + // we must use type identity rather than pointer equality for + // the map key comparison, as we do in consolidateMultiples.) + var seen map[*Named]bool + + // collect methods at current depth + for len(current) > 0 { + var next []embeddedType // embedded types found at current depth + + // field and method sets at current depth, allocated lazily + var fset fieldSet + var mset methodSet + + for _, e := range current { + typ := e.typ + + // If we have a named type, we may have associated methods. + // Look for those first. + if named, _ := typ.(*Named); named != nil { + if seen[named] { + // We have seen this type before, at a more shallow depth + // (note that multiples of this type at the current depth + // were consolidated before). The type at that depth shadows + // this same type at the current depth, so we can ignore + // this one. + continue + } + if seen == nil { + seen = make(map[*Named]bool) + } + seen[named] = true + + mset = mset.add(named.methods, e.index, e.indirect, e.multiples) + + // continue with underlying type + typ = named.underlying + } + + switch t := typ.(type) { + case *Struct: + for i, f := range t.fields { + fset = fset.add(f, e.multiples) + + // Embedded fields are always of the form T or *T where + // T is a type name. If typ appeared multiple times at + // this depth, f.Type appears multiple times at the next + // depth. + if f.anonymous { + typ, isPtr := deref(f.typ) + // TODO(gri) optimization: ignore types that can't + // have fields or methods (only Named, Struct, and + // Interface types need to be considered). + next = append(next, embeddedType{typ, concat(e.index, i), e.indirect || isPtr, e.multiples}) + } + } + + case *Interface: + mset = mset.add(t.allMethods, e.index, true, e.multiples) + } + } + + // Add methods and collisions at this depth to base if no entries with matching + // names exist already. + for k, m := range mset { + if _, found := base[k]; !found { + // Fields collide with methods of the same name at this depth. + if _, found := fset[k]; found { + m = nil // collision + } + if base == nil { + base = make(methodSet) + } + base[k] = m + } + } + + // Multiple fields with matching names collide at this depth and shadow all + // entries further down; add them as collisions to base if no entries with + // matching names exist already. + for k, f := range fset { + if f == nil { + if _, found := base[k]; !found { + if base == nil { + base = make(methodSet) + } + base[k] = nil // collision + } + } + } + + current = consolidateMultiples(next) + } + + if len(base) == 0 { + return &emptyMethodSet + } + + // collect methods + var list []*Selection + for _, m := range base { + if m != nil { + m.recv = T + list = append(list, m) + } + } + // sort by unique name + sort.Slice(list, func(i, j int) bool { + return list[i].obj.Id() < list[j].obj.Id() + }) + return &MethodSet{list} +} + +// A fieldSet is a set of fields and name collisions. +// A collision indicates that multiple fields with the +// same unique id appeared. +type fieldSet map[string]*Var // a nil entry indicates a name collision + +// Add adds field f to the field set s. +// If multiples is set, f appears multiple times +// and is treated as a collision. +func (s fieldSet) add(f *Var, multiples bool) fieldSet { + if s == nil { + s = make(fieldSet) + } + key := f.Id() + // if f is not in the set, add it + if !multiples { + if _, found := s[key]; !found { + s[key] = f + return s + } + } + s[key] = nil // collision + return s +} + +// A methodSet is a set of methods and name collisions. +// A collision indicates that multiple methods with the +// same unique id appeared. +type methodSet map[string]*Selection // a nil entry indicates a name collision + +// Add adds all functions in list to the method set s. +// If multiples is set, every function in list appears multiple times +// and is treated as a collision. +func (s methodSet) add(list []*Func, index []int, indirect bool, multiples bool) methodSet { + if len(list) == 0 { + return s + } + if s == nil { + s = make(methodSet) + } + for i, f := range list { + key := f.Id() + // if f is not in the set, add it + if !multiples { + // TODO(gri) A found method may not be added because it's not in the method set + // (!indirect && ptrRecv(f)). A 2nd method on the same level may be in the method + // set and may not collide with the first one, thus leading to a false positive. + // Is that possible? Investigate. + if _, found := s[key]; !found && (indirect || !ptrRecv(f)) { + s[key] = &Selection{MethodVal, nil, f, concat(index, i), indirect} + continue + } + } + s[key] = nil // collision + } + return s +} + +// ptrRecv reports whether the receiver is of the form *T. +// The receiver must exist. +func ptrRecv(f *Func) bool { + _, isPtr := deref(f.typ.(*Signature).recv.typ) + return isPtr +} diff --git a/third_party/forked/golang/go/types/object.go b/third_party/forked/golang/go/types/object.go new file mode 100644 index 00000000000..633d32712ae --- /dev/null +++ b/third_party/forked/golang/go/types/object.go @@ -0,0 +1,424 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package types + +import ( + "bytes" + "fmt" + "go/ast" + "go/constant" + "go/token" +) + +// An Object describes a named language entity such as a package, +// constant, type, variable, function (incl. methods), or label. +// All objects implement the Object interface. +// +type Object interface { + Parent() *Scope // scope in which this object is declared; nil for methods and struct fields + Pos() token.Pos // position of object identifier in declaration + Pkg() *Package // package to which this object belongs; nil for labels and objects in the Universe scope + Name() string // package local object name + Type() Type // object type + Exported() bool // reports whether the name starts with a capital letter + Id() string // object name if exported, qualified name if not exported (see func Id) + + // String returns a human-readable string of the object. + String() string + + // order reflects a package-level object's source order: if object + // a is before object b in the source, then a.order() < b.order(). + // order returns a value > 0 for package-level objects; it returns + // 0 for all other objects (including objects in file scopes). + order() uint32 + + // setOrder sets the order number of the object. It must be > 0. + setOrder(uint32) + + // setParent sets the parent scope of the object. + setParent(*Scope) + + // sameId reports whether obj.Id() and Id(pkg, name) are the same. + sameId(pkg *Package, name string) bool + + // scopePos returns the start position of the scope of this Object + scopePos() token.Pos + + // setScopePos sets the start position of the scope for this Object. + setScopePos(pos token.Pos) +} + +// Id returns name if it is exported, otherwise it +// returns the name qualified with the package path. +func Id(pkg *Package, name string) string { + if ast.IsExported(name) { + return name + } + // unexported names need the package path for differentiation + // (if there's no package, make sure we don't start with '.' + // as that may change the order of methods between a setup + // inside a package and outside a package - which breaks some + // tests) + path := "_" + // pkg is nil for objects in Universe scope and possibly types + // introduced via Eval (see also comment in object.sameId) + if pkg != nil && pkg.path != "" { + path = pkg.path + } + return path + "." + name +} + +// An object implements the common parts of an Object. +type object struct { + parent *Scope + pos token.Pos + pkg *Package + name string + typ Type + order_ uint32 + scopePos_ token.Pos +} + +func (obj *object) Parent() *Scope { return obj.parent } +func (obj *object) Pos() token.Pos { return obj.pos } +func (obj *object) Pkg() *Package { return obj.pkg } +func (obj *object) Name() string { return obj.name } +func (obj *object) Type() Type { return obj.typ } +func (obj *object) Exported() bool { return ast.IsExported(obj.name) } +func (obj *object) Id() string { return Id(obj.pkg, obj.name) } +func (obj *object) String() string { panic("abstract") } +func (obj *object) order() uint32 { return obj.order_ } +func (obj *object) scopePos() token.Pos { return obj.scopePos_ } + +func (obj *object) setParent(parent *Scope) { obj.parent = parent } +func (obj *object) setOrder(order uint32) { assert(order > 0); obj.order_ = order } +func (obj *object) setScopePos(pos token.Pos) { obj.scopePos_ = pos } + +func (obj *object) sameId(pkg *Package, name string) bool { + // spec: + // "Two identifiers are different if they are spelled differently, + // or if they appear in different packages and are not exported. + // Otherwise, they are the same." + if name != obj.name { + return false + } + // obj.Name == name + if obj.Exported() { + return true + } + // not exported, so packages must be the same (pkg == nil for + // fields in Universe scope; this can only happen for types + // introduced via Eval) + if pkg == nil || obj.pkg == nil { + return pkg == obj.pkg + } + // pkg != nil && obj.pkg != nil + return pkg.path == obj.pkg.path +} + +// A PkgName represents an imported Go package. +// PkgNames don't have a type. +type PkgName struct { + object + imported *Package + used bool // set if the package was used +} + +// NewPkgName returns a new PkgName object representing an imported package. +// The remaining arguments set the attributes found with all Objects. +func NewPkgName(pos token.Pos, pkg *Package, name string, imported *Package) *PkgName { + return &PkgName{object{nil, pos, pkg, name, Typ[Invalid], 0, token.NoPos}, imported, false} +} + +// Imported returns the package that was imported. +// It is distinct from Pkg(), which is the package containing the import statement. +func (obj *PkgName) Imported() *Package { return obj.imported } + +// A Const represents a declared constant. +type Const struct { + object + val constant.Value + visited bool // for initialization cycle detection +} + +// NewConst returns a new constant with value val. +// The remaining arguments set the attributes found with all Objects. +func NewConst(pos token.Pos, pkg *Package, name string, typ Type, val constant.Value) *Const { + return &Const{object{nil, pos, pkg, name, typ, 0, token.NoPos}, val, false} +} + +func (obj *Const) Val() constant.Value { return obj.val } +func (*Const) isDependency() {} // a constant may be a dependency of an initialization expression + +// A TypeName represents a name for a (named or alias) type. +type TypeName struct { + object +} + +// NewTypeName returns a new type name denoting the given typ. +// The remaining arguments set the attributes found with all Objects. +// +// The typ argument may be a defined (Named) type or an alias type. +// It may also be nil such that the returned TypeName can be used as +// argument for NewNamed, which will set the TypeName's type as a side- +// effect. +func NewTypeName(pos token.Pos, pkg *Package, name string, typ Type) *TypeName { + return &TypeName{object{nil, pos, pkg, name, typ, 0, token.NoPos}} +} + +// IsAlias reports whether obj is an alias name for a type. +func (obj *TypeName) IsAlias() bool { + switch t := obj.typ.(type) { + case nil: + return false + case *Basic: + // unsafe.Pointer is not an alias. + if obj.pkg == Unsafe { + return false + } + // Any user-defined type name for a basic type is an alias for a + // basic type (because basic types are pre-declared in the Universe + // scope, outside any package scope), and so is any type name with + // a different name than the name of the basic type it refers to. + // Additionally, we need to look for "byte" and "rune" because they + // are aliases but have the same names (for better error messages). + return obj.pkg != nil || t.name != obj.name || t == universeByte || t == universeRune + case *Named: + return obj != t.obj + default: + return true + } +} + +// A Variable represents a declared variable (including function parameters and results, and struct fields). +type Var struct { + object + anonymous bool // if set, the variable is an anonymous struct field, and name is the type name + visited bool // for initialization cycle detection + isField bool // var is struct field + used bool // set if the variable was used +} + +// NewVar returns a new variable. +// The arguments set the attributes found with all Objects. +func NewVar(pos token.Pos, pkg *Package, name string, typ Type) *Var { + return &Var{object: object{nil, pos, pkg, name, typ, 0, token.NoPos}} +} + +// NewParam returns a new variable representing a function parameter. +func NewParam(pos token.Pos, pkg *Package, name string, typ Type) *Var { + return &Var{object: object{nil, pos, pkg, name, typ, 0, token.NoPos}, used: true} // parameters are always 'used' +} + +// NewField returns a new variable representing a struct field. +// For anonymous (embedded) fields, the name is the unqualified +// type name under which the field is accessible. +func NewField(pos token.Pos, pkg *Package, name string, typ Type, anonymous bool) *Var { + return &Var{object: object{nil, pos, pkg, name, typ, 0, token.NoPos}, anonymous: anonymous, isField: true} +} + +// Anonymous reports whether the variable is an anonymous field. +func (obj *Var) Anonymous() bool { return obj.anonymous } + +// IsField reports whether the variable is a struct field. +func (obj *Var) IsField() bool { return obj.isField } + +func (*Var) isDependency() {} // a variable may be a dependency of an initialization expression + +// A Func represents a declared function, concrete method, or abstract +// (interface) method. Its Type() is always a *Signature. +// An abstract method may belong to many interfaces due to embedding. +type Func struct { + object +} + +// NewFunc returns a new function with the given signature, representing +// the function's type. +func NewFunc(pos token.Pos, pkg *Package, name string, sig *Signature) *Func { + // don't store a nil signature + var typ Type + if sig != nil { + typ = sig + } + return &Func{object{nil, pos, pkg, name, typ, 0, token.NoPos}} +} + +// FullName returns the package- or receiver-type-qualified name of +// function or method obj. +func (obj *Func) FullName() string { + var buf bytes.Buffer + writeFuncName(&buf, obj, nil) + return buf.String() +} + +// Scope returns the scope of the function's body block. +func (obj *Func) Scope() *Scope { return obj.typ.(*Signature).scope } + +func (*Func) isDependency() {} // a function may be a dependency of an initialization expression + +// A Label represents a declared label. +// Labels don't have a type. +type Label struct { + object + used bool // set if the label was used +} + +// NewLabel returns a new label. +func NewLabel(pos token.Pos, pkg *Package, name string) *Label { + return &Label{object{pos: pos, pkg: pkg, name: name, typ: Typ[Invalid]}, false} +} + +// A Builtin represents a built-in function. +// Builtins don't have a valid type. +type Builtin struct { + object + id builtinId +} + +func newBuiltin(id builtinId) *Builtin { + return &Builtin{object{name: predeclaredFuncs[id].name, typ: Typ[Invalid]}, id} +} + +// Nil represents the predeclared value nil. +type Nil struct { + object +} + +func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) { + var tname *TypeName + typ := obj.Type() + + switch obj := obj.(type) { + case *PkgName: + fmt.Fprintf(buf, "package %s", obj.Name()) + if path := obj.imported.path; path != "" && path != obj.name { + fmt.Fprintf(buf, " (%q)", path) + } + return + + case *Const: + buf.WriteString("const") + + case *TypeName: + tname = obj + buf.WriteString("type") + + case *Var: + if obj.isField { + buf.WriteString("field") + } else { + buf.WriteString("var") + } + + case *Func: + buf.WriteString("func ") + writeFuncName(buf, obj, qf) + if typ != nil { + WriteSignature(buf, typ.(*Signature), qf) + } + return + + case *Label: + buf.WriteString("label") + typ = nil + + case *Builtin: + buf.WriteString("builtin") + typ = nil + + case *Nil: + buf.WriteString("nil") + return + + default: + panic(fmt.Sprintf("writeObject(%T)", obj)) + } + + buf.WriteByte(' ') + + // For package-level objects, qualify the name. + if obj.Pkg() != nil && obj.Pkg().scope.Lookup(obj.Name()) == obj { + writePackage(buf, obj.Pkg(), qf) + } + buf.WriteString(obj.Name()) + + if typ == nil { + return + } + + if tname != nil { + // We have a type object: Don't print anything more for + // basic types since there's no more information (names + // are the same; see also comment in TypeName.IsAlias). + if _, ok := typ.(*Basic); ok { + return + } + if tname.IsAlias() { + buf.WriteString(" =") + } else { + typ = typ.Underlying() + } + } + + buf.WriteByte(' ') + WriteType(buf, typ, qf) +} + +func writePackage(buf *bytes.Buffer, pkg *Package, qf Qualifier) { + if pkg == nil { + return + } + var s string + if qf != nil { + s = qf(pkg) + } else { + s = pkg.Path() + } + if s != "" { + buf.WriteString(s) + buf.WriteByte('.') + } +} + +// ObjectString returns the string form of obj. +// The Qualifier controls the printing of +// package-level objects, and may be nil. +func ObjectString(obj Object, qf Qualifier) string { + var buf bytes.Buffer + writeObject(&buf, obj, qf) + return buf.String() +} + +func (obj *PkgName) String() string { return ObjectString(obj, nil) } +func (obj *Const) String() string { return ObjectString(obj, nil) } +func (obj *TypeName) String() string { return ObjectString(obj, nil) } +func (obj *Var) String() string { return ObjectString(obj, nil) } +func (obj *Func) String() string { return ObjectString(obj, nil) } +func (obj *Label) String() string { return ObjectString(obj, nil) } +func (obj *Builtin) String() string { return ObjectString(obj, nil) } +func (obj *Nil) String() string { return ObjectString(obj, nil) } + +func writeFuncName(buf *bytes.Buffer, f *Func, qf Qualifier) { + if f.typ != nil { + sig := f.typ.(*Signature) + if recv := sig.Recv(); recv != nil { + buf.WriteByte('(') + if _, ok := recv.Type().(*Interface); ok { + // gcimporter creates abstract methods of + // named interfaces using the interface type + // (not the named type) as the receiver. + // Don't print it in full. + buf.WriteString("interface") + } else { + WriteType(buf, recv.Type(), qf) + } + buf.WriteByte(')') + buf.WriteByte('.') + } else if f.pkg != nil { + writePackage(buf, f.pkg, qf) + } + } + buf.WriteString(f.name) +} diff --git a/third_party/forked/golang/go/types/objset.go b/third_party/forked/golang/go/types/objset.go new file mode 100644 index 00000000000..55eb74addba --- /dev/null +++ b/third_party/forked/golang/go/types/objset.go @@ -0,0 +1,31 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements objsets. +// +// An objset is similar to a Scope but objset elements +// are identified by their unique id, instead of their +// object name. + +package types + +// An objset is a set of objects identified by their unique id. +// The zero value for objset is a ready-to-use empty objset. +type objset map[string]Object // initialized lazily + +// insert attempts to insert an object obj into objset s. +// If s already contains an alternative object alt with +// the same name, insert leaves s unchanged and returns alt. +// Otherwise it inserts obj and returns nil. +func (s *objset) insert(obj Object) Object { + id := obj.Id() + if alt := (*s)[id]; alt != nil { + return alt + } + if *s == nil { + *s = make(map[string]Object) + } + (*s)[id] = obj + return nil +} diff --git a/third_party/forked/golang/go/types/operand.go b/third_party/forked/golang/go/types/operand.go new file mode 100644 index 00000000000..07247bd6f58 --- /dev/null +++ b/third_party/forked/golang/go/types/operand.go @@ -0,0 +1,275 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file defines operands and associated operations. + +package types + +import ( + "bytes" + "go/ast" + "go/constant" + "go/token" +) + +// An operandMode specifies the (addressing) mode of an operand. +type operandMode byte + +const ( + invalid operandMode = iota // operand is invalid + novalue // operand represents no value (result of a function call w/o result) + builtin // operand is a built-in function + typexpr // operand is a type + constant_ // operand is a constant; the operand's typ is a Basic type + variable // operand is an addressable variable + mapindex // operand is a map index expression (acts like a variable on lhs, commaok on rhs of an assignment) + value // operand is a computed value + commaok // like value, but operand may be used in a comma,ok expression +) + +var operandModeString = [...]string{ + invalid: "invalid operand", + novalue: "no value", + builtin: "built-in", + typexpr: "type", + constant_: "constant", + variable: "variable", + mapindex: "map index expression", + value: "value", + commaok: "comma, ok expression", +} + +// An operand represents an intermediate value during type checking. +// Operands have an (addressing) mode, the expression evaluating to +// the operand, the operand's type, a value for constants, and an id +// for built-in functions. +// The zero value of operand is a ready to use invalid operand. +// +type operand struct { + mode operandMode + expr ast.Expr + typ Type + val constant.Value + id builtinId +} + +// pos returns the position of the expression corresponding to x. +// If x is invalid the position is token.NoPos. +// +func (x *operand) pos() token.Pos { + // x.expr may not be set if x is invalid + if x.expr == nil { + return token.NoPos + } + return x.expr.Pos() +} + +// Operand string formats +// (not all "untyped" cases can appear due to the type system, +// but they fall out naturally here) +// +// mode format +// +// invalid ( ) +// novalue ( ) +// builtin ( ) +// typexpr ( ) +// +// constant ( ) +// constant ( of type ) +// constant ( ) +// constant ( of type ) +// +// variable ( ) +// variable ( of type ) +// +// mapindex ( ) +// mapindex ( of type ) +// +// value ( ) +// value ( of type ) +// +// commaok ( ) +// commaok ( of type ) +// +func operandString(x *operand, qf Qualifier) string { + var buf bytes.Buffer + + var expr string + if x.expr != nil { + expr = ExprString(x.expr) + } else { + switch x.mode { + case builtin: + expr = predeclaredFuncs[x.id].name + case typexpr: + expr = TypeString(x.typ, qf) + case constant_: + expr = x.val.String() + } + } + + // ( + if expr != "" { + buf.WriteString(expr) + buf.WriteString(" (") + } + + // + hasType := false + switch x.mode { + case invalid, novalue, builtin, typexpr: + // no type + default: + // should have a type, but be cautious (don't crash during printing) + if x.typ != nil { + if isUntyped(x.typ) { + buf.WriteString(x.typ.(*Basic).name) + buf.WriteByte(' ') + break + } + hasType = true + } + } + + // + buf.WriteString(operandModeString[x.mode]) + + // + if x.mode == constant_ { + if s := x.val.String(); s != expr { + buf.WriteByte(' ') + buf.WriteString(s) + } + } + + // + if hasType { + if x.typ != Typ[Invalid] { + buf.WriteString(" of type ") + WriteType(&buf, x.typ, qf) + } else { + buf.WriteString(" with invalid type") + } + } + + // ) + if expr != "" { + buf.WriteByte(')') + } + + return buf.String() +} + +func (x *operand) String() string { + return operandString(x, nil) +} + +// setConst sets x to the untyped constant for literal lit. +func (x *operand) setConst(tok token.Token, lit string) { + var kind BasicKind + switch tok { + case token.INT: + kind = UntypedInt + case token.FLOAT: + kind = UntypedFloat + case token.IMAG: + kind = UntypedComplex + case token.CHAR: + kind = UntypedRune + case token.STRING: + kind = UntypedString + default: + unreachable() + } + + x.mode = constant_ + x.typ = Typ[kind] + x.val = constant.MakeFromLiteral(lit, tok, 0) +} + +// isNil reports whether x is the nil value. +func (x *operand) isNil() bool { + return x.mode == value && x.typ == Typ[UntypedNil] +} + +// TODO(gri) The functions operand.assignableTo, checker.convertUntyped, +// checker.representable, and checker.assignment are +// overlapping in functionality. Need to simplify and clean up. + +// assignableTo reports whether x is assignable to a variable of type T. +// If the result is false and a non-nil reason is provided, it may be set +// to a more detailed explanation of the failure (result != ""). +func (x *operand) assignableTo(conf *Config, T Type, reason *string) bool { + if x.mode == invalid || T == Typ[Invalid] { + return true // avoid spurious errors + } + + V := x.typ + + // x's type is identical to T + if Identical(V, T) { + return true + } + + Vu := V.Underlying() + Tu := T.Underlying() + + // x is an untyped value representable by a value of type T + // TODO(gri) This is borrowing from checker.convertUntyped and + // checker.representable. Need to clean up. + if isUntyped(Vu) { + switch t := Tu.(type) { + case *Basic: + if x.isNil() && t.kind == UnsafePointer { + return true + } + if x.mode == constant_ { + return representableConst(x.val, conf, t, nil) + } + // The result of a comparison is an untyped boolean, + // but may not be a constant. + if Vb, _ := Vu.(*Basic); Vb != nil { + return Vb.kind == UntypedBool && isBoolean(Tu) + } + case *Interface: + return x.isNil() || t.Empty() + case *Pointer, *Signature, *Slice, *Map, *Chan: + return x.isNil() + } + } + // Vu is typed + + // x's type V and T have identical underlying types + // and at least one of V or T is not a named type + if Identical(Vu, Tu) && (!isNamed(V) || !isNamed(T)) { + return true + } + + // T is an interface type and x implements T + if Ti, ok := Tu.(*Interface); ok { + if m, wrongType := MissingMethod(x.typ, Ti, true); m != nil /* Implements(x.typ, Ti) */ { + if reason != nil { + if wrongType { + *reason = "wrong type for method " + m.Name() + } else { + *reason = "missing method " + m.Name() + } + } + return false + } + return true + } + + // x is a bidirectional channel value, T is a channel + // type, x's type V and T have identical element types, + // and at least one of V or T is not a named type + if Vc, ok := Vu.(*Chan); ok && Vc.dir == SendRecv { + if Tc, ok := Tu.(*Chan); ok && Identical(Vc.elem, Tc.elem) { + return !isNamed(V) || !isNamed(T) + } + } + + return false +} diff --git a/third_party/forked/golang/go/types/ordering.go b/third_party/forked/golang/go/types/ordering.go new file mode 100644 index 00000000000..3579abf7d7b --- /dev/null +++ b/third_party/forked/golang/go/types/ordering.go @@ -0,0 +1,123 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements resolveOrder. + +package types + +import ( + "go/ast" + "sort" +) + +// resolveOrder computes the order in which package-level objects +// must be type-checked. +// +// Interface types appear first in the list, sorted topologically +// by dependencies on embedded interfaces that are also declared +// in this package, followed by all other objects sorted in source +// order. +// +// TODO(gri) Consider sorting all types by dependencies here, and +// in the process check _and_ report type cycles. This may simplify +// the full type-checking phase. +// +func (check *Checker) resolveOrder() []Object { + var ifaces, others []Object + + // collect interface types with their dependencies, and all other objects + for obj := range check.objMap { + if ityp := check.interfaceFor(obj); ityp != nil { + ifaces = append(ifaces, obj) + // determine dependencies on embedded interfaces + for _, f := range ityp.Methods.List { + if len(f.Names) == 0 { + // Embedded interface: The type must be a (possibly + // qualified) identifier denoting another interface. + // Imported interfaces are already fully resolved, + // so we can ignore qualified identifiers. + if ident, _ := f.Type.(*ast.Ident); ident != nil { + embedded := check.pkg.scope.Lookup(ident.Name) + if check.interfaceFor(embedded) != nil { + check.objMap[obj].addDep(embedded) + } + } + } + } + } else { + others = append(others, obj) + } + } + + // final object order + var order []Object + + // sort interface types topologically by dependencies, + // and in source order if there are no dependencies + sort.Sort(inSourceOrder(ifaces)) + visited := make(objSet) + for _, obj := range ifaces { + check.appendInPostOrder(&order, obj, visited) + } + + // sort everything else in source order + sort.Sort(inSourceOrder(others)) + + return append(order, others...) +} + +// interfaceFor returns the AST interface denoted by obj, or nil. +func (check *Checker) interfaceFor(obj Object) *ast.InterfaceType { + tname, _ := obj.(*TypeName) + if tname == nil { + return nil // not a type + } + d := check.objMap[obj] + if d == nil { + check.dump("%s: %s should have been declared", obj.Pos(), obj.Name()) + unreachable() + } + if d.typ == nil { + return nil // invalid AST - ignore (will be handled later) + } + ityp, _ := d.typ.(*ast.InterfaceType) + return ityp +} + +func (check *Checker) appendInPostOrder(order *[]Object, obj Object, visited objSet) { + if visited[obj] { + // We've already seen this object; either because it's + // already added to order, or because we have a cycle. + // In both cases we stop. Cycle errors are reported + // when type-checking types. + return + } + visited[obj] = true + + d := check.objMap[obj] + for _, obj := range orderedSetObjects(d.deps) { + check.appendInPostOrder(order, obj, visited) + } + + *order = append(*order, obj) +} + +func orderedSetObjects(set objSet) []Object { + list := make([]Object, len(set)) + i := 0 + for obj := range set { + // we don't care about the map element value + list[i] = obj + i++ + } + sort.Sort(inSourceOrder(list)) + return list +} + +// inSourceOrder implements the sort.Sort interface. +type inSourceOrder []Object + +func (a inSourceOrder) Len() int { return len(a) } +func (a inSourceOrder) Less(i, j int) bool { return a[i].order() < a[j].order() } +func (a inSourceOrder) Swap(i, j int) { a[i], a[j] = a[j], a[i] } diff --git a/third_party/forked/golang/go/types/package.go b/third_party/forked/golang/go/types/package.go new file mode 100644 index 00000000000..cd202a0ed9f --- /dev/null +++ b/third_party/forked/golang/go/types/package.go @@ -0,0 +1,64 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package types + +import ( + "fmt" + "go/token" +) + +// A Package describes a Go package. +type Package struct { + path string + name string + scope *Scope + complete bool + imports []*Package + fake bool // scope lookup errors are silently dropped if package is fake (internal use only) +} + +// NewPackage returns a new Package for the given package path and name. +// The package is not complete and contains no explicit imports. +func NewPackage(path, name string) *Package { + scope := NewScope(Universe, token.NoPos, token.NoPos, fmt.Sprintf("package %q", path)) + return &Package{path: path, name: name, scope: scope} +} + +// Path returns the package path. +func (pkg *Package) Path() string { return pkg.path } + +// Name returns the package name. +func (pkg *Package) Name() string { return pkg.name } + +// SetName sets the package name. +func (pkg *Package) SetName(name string) { pkg.name = name } + +// Scope returns the (complete or incomplete) package scope +// holding the objects declared at package level (TypeNames, +// Consts, Vars, and Funcs). +func (pkg *Package) Scope() *Scope { return pkg.scope } + +// A package is complete if its scope contains (at least) all +// exported objects; otherwise it is incomplete. +func (pkg *Package) Complete() bool { return pkg.complete } + +// MarkComplete marks a package as complete. +func (pkg *Package) MarkComplete() { pkg.complete = true } + +// Imports returns the list of packages directly imported by +// pkg; the list is in source order. +// +// If pkg was loaded from export data, Imports includes packages that +// provide package-level objects referenced by pkg. This may be more or +// less than the set of packages directly imported by pkg's source code. +func (pkg *Package) Imports() []*Package { return pkg.imports } + +// SetImports sets the list of explicitly imported packages to list. +// It is the caller's responsibility to make sure list elements are unique. +func (pkg *Package) SetImports(list []*Package) { pkg.imports = list } + +func (pkg *Package) String() string { + return fmt.Sprintf("package %s (%q)", pkg.name, pkg.path) +} diff --git a/third_party/forked/golang/go/types/predicates.go b/third_party/forked/golang/go/types/predicates.go new file mode 100644 index 00000000000..1ca146f5904 --- /dev/null +++ b/third_party/forked/golang/go/types/predicates.go @@ -0,0 +1,320 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements commonly used type predicates. + +package types + +import "sort" + +func isNamed(typ Type) bool { + if _, ok := typ.(*Basic); ok { + return ok + } + _, ok := typ.(*Named) + return ok +} + +func isBoolean(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsBoolean != 0 +} + +func isInteger(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsInteger != 0 +} + +func isUnsigned(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsUnsigned != 0 +} + +func isFloat(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsFloat != 0 +} + +func isComplex(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsComplex != 0 +} + +func isNumeric(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsNumeric != 0 +} + +func isString(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsString != 0 +} + +func isTyped(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return !ok || t.info&IsUntyped == 0 +} + +func isUntyped(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsUntyped != 0 +} + +func isOrdered(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsOrdered != 0 +} + +func isConstType(typ Type) bool { + t, ok := typ.Underlying().(*Basic) + return ok && t.info&IsConstType != 0 +} + +// IsInterface reports whether typ is an interface type. +func IsInterface(typ Type) bool { + _, ok := typ.Underlying().(*Interface) + return ok +} + +// Comparable reports whether values of type T are comparable. +func Comparable(T Type) bool { + switch t := T.Underlying().(type) { + case *Basic: + // assume invalid types to be comparable + // to avoid follow-up errors + return t.kind != UntypedNil + case *Pointer, *Interface, *Chan: + return true + case *Struct: + for _, f := range t.fields { + if !Comparable(f.typ) { + return false + } + } + return true + case *Array: + return Comparable(t.elem) + } + return false +} + +// hasNil reports whether a type includes the nil value. +func hasNil(typ Type) bool { + switch t := typ.Underlying().(type) { + case *Basic: + return t.kind == UnsafePointer + case *Slice, *Pointer, *Signature, *Interface, *Map, *Chan: + return true + } + return false +} + +// Identical reports whether x and y are identical types. +// Receivers of Signature types are ignored. +func Identical(x, y Type) bool { + return identical(x, y, true, nil) +} + +// IdenticalIgnoreTags reports whether x and y are identical types if tags are ignored. +// Receivers of Signature types are ignored. +func IdenticalIgnoreTags(x, y Type) bool { + return identical(x, y, false, nil) +} + +// An ifacePair is a node in a stack of interface type pairs compared for identity. +type ifacePair struct { + x, y *Interface + prev *ifacePair +} + +func (p *ifacePair) identical(q *ifacePair) bool { + return p.x == q.x && p.y == q.y || p.x == q.y && p.y == q.x +} + +func identical(x, y Type, cmpTags bool, p *ifacePair) bool { + if x == y { + return true + } + + switch x := x.(type) { + case *Basic: + // Basic types are singletons except for the rune and byte + // aliases, thus we cannot solely rely on the x == y check + // above. See also comment in TypeName.IsAlias. + if y, ok := y.(*Basic); ok { + return x.kind == y.kind + } + + case *Array: + // Two array types are identical if they have identical element types + // and the same array length. + if y, ok := y.(*Array); ok { + // If one or both array lengths are unknown (< 0) due to some error, + // assume they are the same to avoid spurious follow-on errors. + return (x.len < 0 || y.len < 0 || x.len == y.len) && identical(x.elem, y.elem, cmpTags, p) + } + + case *Slice: + // Two slice types are identical if they have identical element types. + if y, ok := y.(*Slice); ok { + return identical(x.elem, y.elem, cmpTags, p) + } + + case *Struct: + // Two struct types are identical if they have the same sequence of fields, + // and if corresponding fields have the same names, and identical types, + // and identical tags. Two anonymous fields are considered to have the same + // name. Lower-case field names from different packages are always different. + if y, ok := y.(*Struct); ok { + if x.NumFields() == y.NumFields() { + for i, f := range x.fields { + g := y.fields[i] + if f.anonymous != g.anonymous || + cmpTags && x.Tag(i) != y.Tag(i) || + !f.sameId(g.pkg, g.name) || + !identical(f.typ, g.typ, cmpTags, p) { + return false + } + } + return true + } + } + + case *Pointer: + // Two pointer types are identical if they have identical base types. + if y, ok := y.(*Pointer); ok { + return identical(x.base, y.base, cmpTags, p) + } + + case *Tuple: + // Two tuples types are identical if they have the same number of elements + // and corresponding elements have identical types. + if y, ok := y.(*Tuple); ok { + if x.Len() == y.Len() { + if x != nil { + for i, v := range x.vars { + w := y.vars[i] + if !identical(v.typ, w.typ, cmpTags, p) { + return false + } + } + } + return true + } + } + + case *Signature: + // Two function types are identical if they have the same number of parameters + // and result values, corresponding parameter and result types are identical, + // and either both functions are variadic or neither is. Parameter and result + // names are not required to match. + if y, ok := y.(*Signature); ok { + return x.variadic == y.variadic && + identical(x.params, y.params, cmpTags, p) && + identical(x.results, y.results, cmpTags, p) + } + + case *Interface: + // Two interface types are identical if they have the same set of methods with + // the same names and identical function types. Lower-case method names from + // different packages are always different. The order of the methods is irrelevant. + if y, ok := y.(*Interface); ok { + a := x.allMethods + b := y.allMethods + if len(a) == len(b) { + // Interface types are the only types where cycles can occur + // that are not "terminated" via named types; and such cycles + // can only be created via method parameter types that are + // anonymous interfaces (directly or indirectly) embedding + // the current interface. Example: + // + // type T interface { + // m() interface{T} + // } + // + // If two such (differently named) interfaces are compared, + // endless recursion occurs if the cycle is not detected. + // + // If x and y were compared before, they must be equal + // (if they were not, the recursion would have stopped); + // search the ifacePair stack for the same pair. + // + // This is a quadratic algorithm, but in practice these stacks + // are extremely short (bounded by the nesting depth of interface + // type declarations that recur via parameter types, an extremely + // rare occurrence). An alternative implementation might use a + // "visited" map, but that is probably less efficient overall. + q := &ifacePair{x, y, p} + for p != nil { + if p.identical(q) { + return true // same pair was compared before + } + p = p.prev + } + if debug { + assert(sort.IsSorted(byUniqueMethodName(a))) + assert(sort.IsSorted(byUniqueMethodName(b))) + } + for i, f := range a { + g := b[i] + if f.Id() != g.Id() || !identical(f.typ, g.typ, cmpTags, q) { + return false + } + } + return true + } + } + + case *Map: + // Two map types are identical if they have identical key and value types. + if y, ok := y.(*Map); ok { + return identical(x.key, y.key, cmpTags, p) && identical(x.elem, y.elem, cmpTags, p) + } + + case *Chan: + // Two channel types are identical if they have identical value types + // and the same direction. + if y, ok := y.(*Chan); ok { + return x.dir == y.dir && identical(x.elem, y.elem, cmpTags, p) + } + + case *Named: + // Two named types are identical if their type names originate + // in the same type declaration. + if y, ok := y.(*Named); ok { + return x.obj == y.obj + } + + case nil: + + default: + unreachable() + } + + return false +} + +// Default returns the default "typed" type for an "untyped" type; +// it returns the incoming type for all other types. The default type +// for untyped nil is untyped nil. +// +func Default(typ Type) Type { + if t, ok := typ.(*Basic); ok { + switch t.kind { + case UntypedBool: + return Typ[Bool] + case UntypedInt: + return Typ[Int] + case UntypedRune: + return universeRune // use 'rune' name + case UntypedFloat: + return Typ[Float64] + case UntypedComplex: + return Typ[Complex128] + case UntypedString: + return Typ[String] + } + } + return typ +} diff --git a/third_party/forked/golang/go/types/resolver.go b/third_party/forked/golang/go/types/resolver.go new file mode 100644 index 00000000000..d03c1799af9 --- /dev/null +++ b/third_party/forked/golang/go/types/resolver.go @@ -0,0 +1,542 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package types + +import ( + "fmt" + "go/ast" + "go/constant" + "go/token" + "strconv" + "strings" + "unicode" +) + +// A declInfo describes a package-level const, type, var, or func declaration. +type declInfo struct { + file *Scope // scope of file containing this declaration + lhs []*Var // lhs of n:1 variable declarations, or nil + typ ast.Expr // type, or nil + init ast.Expr // init/orig expression, or nil + fdecl *ast.FuncDecl // func declaration, or nil + alias bool // type alias declaration + + // The deps field tracks initialization expression dependencies. + // As a special (overloaded) case, it also tracks dependencies of + // interface types on embedded interfaces (see ordering.go). + deps objSet // lazily initialized +} + +// An objSet is simply a set of objects. +type objSet map[Object]bool + +// hasInitializer reports whether the declared object has an initialization +// expression or function body. +func (d *declInfo) hasInitializer() bool { + return d.init != nil || d.fdecl != nil && d.fdecl.Body != nil +} + +// addDep adds obj to the set of objects d's init expression depends on. +func (d *declInfo) addDep(obj Object) { + m := d.deps + if m == nil { + m = make(objSet) + d.deps = m + } + m[obj] = true +} + +// arityMatch checks that the lhs and rhs of a const or var decl +// have the appropriate number of names and init exprs. For const +// decls, init is the value spec providing the init exprs; for +// var decls, init is nil (the init exprs are in s in this case). +func (check *Checker) arityMatch(s, init *ast.ValueSpec) { + l := len(s.Names) + r := len(s.Values) + if init != nil { + r = len(init.Values) + } + + switch { + case init == nil && r == 0: + // var decl w/o init expr + if s.Type == nil { + check.errorf(s.Pos(), "missing type or init expr") + } + case l < r: + if l < len(s.Values) { + // init exprs from s + n := s.Values[l] + check.errorf(n.Pos(), "extra init expr %s", n) + // TODO(gri) avoid declared but not used error here + } else { + // init exprs "inherited" + check.errorf(s.Pos(), "extra init expr at %s", check.fset.Position(init.Pos())) + // TODO(gri) avoid declared but not used error here + } + case l > r && (init != nil || r != 1): + n := s.Names[r] + check.errorf(n.Pos(), "missing init expr for %s", n) + } +} + +func validatedImportPath(path string) (string, error) { + s, err := strconv.Unquote(path) + if err != nil { + return "", err + } + if s == "" { + return "", fmt.Errorf("empty string") + } + const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD" + for _, r := range s { + if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) { + return s, fmt.Errorf("invalid character %#U", r) + } + } + return s, nil +} + +// declarePkgObj declares obj in the package scope, records its ident -> obj mapping, +// and updates check.objMap. The object must not be a function or method. +func (check *Checker) declarePkgObj(ident *ast.Ident, obj Object, d *declInfo) { + assert(ident.Name == obj.Name()) + + // spec: "A package-scope or file-scope identifier with name init + // may only be declared to be a function with this (func()) signature." + if ident.Name == "init" { + check.errorf(ident.Pos(), "cannot declare init - must be func") + return + } + + // spec: "The main package must have package name main and declare + // a function main that takes no arguments and returns no value." + if ident.Name == "main" && check.pkg.name == "main" { + check.errorf(ident.Pos(), "cannot declare main - must be func") + return + } + + check.declare(check.pkg.scope, ident, obj, token.NoPos) + check.objMap[obj] = d + obj.setOrder(uint32(len(check.objMap))) +} + +// filename returns a filename suitable for debugging output. +func (check *Checker) filename(fileNo int) string { + file := check.files[fileNo] + if pos := file.Pos(); pos.IsValid() { + return check.fset.File(pos).Name() + } + return fmt.Sprintf("file[%d]", fileNo) +} + +func (check *Checker) importPackage(pos token.Pos, path, dir string) *Package { + // If we already have a package for the given (path, dir) + // pair, use it instead of doing a full import. + // Checker.impMap only caches packages that are marked Complete + // or fake (dummy packages for failed imports). Incomplete but + // non-fake packages do require an import to complete them. + key := importKey{path, dir} + imp := check.impMap[key] + if imp != nil { + return imp + } + + // no package yet => import it + if path == "C" && check.conf.FakeImportC { + imp = NewPackage("C", "C") + imp.fake = true + } else { + // ordinary import + var err error + if importer := check.conf.Importer; importer == nil { + err = fmt.Errorf("Config.Importer not installed") + } else if importerFrom, ok := importer.(ImporterFrom); ok { + imp, err = importerFrom.ImportFrom(path, dir, 0) + if imp == nil && err == nil { + err = fmt.Errorf("Config.Importer.ImportFrom(%s, %s, 0) returned nil but no error", path, dir) + } + } else { + imp, err = importer.Import(path) + if imp == nil && err == nil { + err = fmt.Errorf("Config.Importer.Import(%s) returned nil but no error", path) + } + } + // make sure we have a valid package name + // (errors here can only happen through manipulation of packages after creation) + if err == nil && imp != nil && (imp.name == "_" || imp.name == "") { + err = fmt.Errorf("invalid package name: %q", imp.name) + imp = nil // create fake package below + } + if err != nil { + check.errorf(pos, "could not import %s (%s)", path, err) + if imp == nil { + // create a new fake package + // come up with a sensible package name (heuristic) + name := path + if i := len(name); i > 0 && name[i-1] == '/' { + name = name[:i-1] + } + if i := strings.LastIndex(name, "/"); i >= 0 { + name = name[i+1:] + } + imp = NewPackage(path, name) + } + // continue to use the package as best as we can + imp.fake = true // avoid follow-up lookup failures + } + } + + // package should be complete or marked fake, but be cautious + if imp.complete || imp.fake { + check.impMap[key] = imp + return imp + } + + // something went wrong (importer may have returned incomplete package without error) + return nil +} + +// collectObjects collects all file and package objects and inserts them +// into their respective scopes. It also performs imports and associates +// methods with receiver base type names. +func (check *Checker) collectObjects() { + pkg := check.pkg + + // pkgImports is the set of packages already imported by any package file seen + // so far. Used to avoid duplicate entries in pkg.imports. Allocate and populate + // it (pkg.imports may not be empty if we are checking test files incrementally). + // Note that pkgImports is keyed by package (and thus package path), not by an + // importKey value. Two different importKey values may map to the same package + // which is why we cannot use the check.impMap here. + var pkgImports = make(map[*Package]bool) + for _, imp := range pkg.imports { + pkgImports[imp] = true + } + + for fileNo, file := range check.files { + // The package identifier denotes the current package, + // but there is no corresponding package object. + check.recordDef(file.Name, nil) + + // Use the actual source file extent rather than *ast.File extent since the + // latter doesn't include comments which appear at the start or end of the file. + // Be conservative and use the *ast.File extent if we don't have a *token.File. + pos, end := file.Pos(), file.End() + if f := check.fset.File(file.Pos()); f != nil { + pos, end = token.Pos(f.Base()), token.Pos(f.Base()+f.Size()) + } + fileScope := NewScope(check.pkg.scope, pos, end, check.filename(fileNo)) + check.recordScope(file, fileScope) + + // determine file directory, necessary to resolve imports + // FileName may be "" (typically for tests) in which case + // we get "." as the directory which is what we would want. + fileDir := dir(check.fset.Position(file.Name.Pos()).Filename) + + for _, decl := range file.Decls { + switch d := decl.(type) { + case *ast.BadDecl: + // ignore + + case *ast.GenDecl: + var last *ast.ValueSpec // last ValueSpec with type or init exprs seen + for iota, spec := range d.Specs { + switch s := spec.(type) { + case *ast.ImportSpec: + // import package + path, err := validatedImportPath(s.Path.Value) + if err != nil { + check.errorf(s.Path.Pos(), "invalid import path (%s)", err) + continue + } + + imp := check.importPackage(s.Path.Pos(), path, fileDir) + if imp == nil { + continue + } + + // add package to list of explicit imports + // (this functionality is provided as a convenience + // for clients; it is not needed for type-checking) + if !pkgImports[imp] { + pkgImports[imp] = true + pkg.imports = append(pkg.imports, imp) + } + + // local name overrides imported package name + name := imp.name + if s.Name != nil { + name = s.Name.Name + if path == "C" { + // match cmd/compile (not prescribed by spec) + check.errorf(s.Name.Pos(), `cannot rename import "C"`) + continue + } + if name == "init" { + check.errorf(s.Name.Pos(), "cannot declare init - must be func") + continue + } + } + + obj := NewPkgName(s.Pos(), pkg, name, imp) + if s.Name != nil { + // in a dot-import, the dot represents the package + check.recordDef(s.Name, obj) + } else { + check.recordImplicit(s, obj) + } + + if path == "C" { + // match cmd/compile (not prescribed by spec) + obj.used = true + } + + // add import to file scope + if name == "." { + // merge imported scope with file scope + for _, obj := range imp.scope.elems { + // A package scope may contain non-exported objects, + // do not import them! + if obj.Exported() { + // TODO(gri) When we import a package, we create + // a new local package object. We should do the + // same for each dot-imported object. That way + // they can have correct position information. + // (We must not modify their existing position + // information because the same package - found + // via Config.Packages - may be dot-imported in + // another package!) + check.declare(fileScope, nil, obj, token.NoPos) + } + } + // add position to set of dot-import positions for this file + // (this is only needed for "imported but not used" errors) + check.addUnusedDotImport(fileScope, imp, s.Pos()) + } else { + // declare imported package object in file scope + check.declare(fileScope, nil, obj, token.NoPos) + } + + case *ast.ValueSpec: + switch d.Tok { + case token.CONST: + // determine which initialization expressions to use + switch { + case s.Type != nil || len(s.Values) > 0: + last = s + case last == nil: + last = new(ast.ValueSpec) // make sure last exists + } + + // declare all constants + for i, name := range s.Names { + obj := NewConst(name.Pos(), pkg, name.Name, nil, constant.MakeInt64(int64(iota))) + + var init ast.Expr + if i < len(last.Values) { + init = last.Values[i] + } + + d := &declInfo{file: fileScope, typ: last.Type, init: init} + check.declarePkgObj(name, obj, d) + } + + check.arityMatch(s, last) + + case token.VAR: + lhs := make([]*Var, len(s.Names)) + // If there's exactly one rhs initializer, use + // the same declInfo d1 for all lhs variables + // so that each lhs variable depends on the same + // rhs initializer (n:1 var declaration). + var d1 *declInfo + if len(s.Values) == 1 { + // The lhs elements are only set up after the for loop below, + // but that's ok because declareVar only collects the declInfo + // for a later phase. + d1 = &declInfo{file: fileScope, lhs: lhs, typ: s.Type, init: s.Values[0]} + } + + // declare all variables + for i, name := range s.Names { + obj := NewVar(name.Pos(), pkg, name.Name, nil) + lhs[i] = obj + + d := d1 + if d == nil { + // individual assignments + var init ast.Expr + if i < len(s.Values) { + init = s.Values[i] + } + d = &declInfo{file: fileScope, typ: s.Type, init: init} + } + + check.declarePkgObj(name, obj, d) + } + + check.arityMatch(s, nil) + + default: + check.invalidAST(s.Pos(), "invalid token %s", d.Tok) + } + + case *ast.TypeSpec: + obj := NewTypeName(s.Name.Pos(), pkg, s.Name.Name, nil) + check.declarePkgObj(s.Name, obj, &declInfo{file: fileScope, typ: s.Type, alias: s.Assign.IsValid()}) + + default: + check.invalidAST(s.Pos(), "unknown ast.Spec node %T", s) + } + } + + case *ast.FuncDecl: + name := d.Name.Name + obj := NewFunc(d.Name.Pos(), pkg, name, nil) + if d.Recv == nil { + // regular function + if name == "init" { + // don't declare init functions in the package scope - they are invisible + obj.parent = pkg.scope + check.recordDef(d.Name, obj) + // init functions must have a body + if d.Body == nil { + check.softErrorf(obj.pos, "missing function body") + } + } else { + check.declare(pkg.scope, d.Name, obj, token.NoPos) + } + } else { + // method + check.recordDef(d.Name, obj) + // Associate method with receiver base type name, if possible. + // Ignore methods that have an invalid receiver, or a blank _ + // receiver name. They will be type-checked later, with regular + // functions. + if list := d.Recv.List; len(list) > 0 { + typ := unparen(list[0].Type) + if ptr, _ := typ.(*ast.StarExpr); ptr != nil { + typ = unparen(ptr.X) + } + if base, _ := typ.(*ast.Ident); base != nil && base.Name != "_" { + check.assocMethod(base.Name, obj) + } + } + } + info := &declInfo{file: fileScope, fdecl: d} + check.objMap[obj] = info + obj.setOrder(uint32(len(check.objMap))) + + default: + check.invalidAST(d.Pos(), "unknown ast.Decl node %T", d) + } + } + } + + // verify that objects in package and file scopes have different names + for _, scope := range check.pkg.scope.children /* file scopes */ { + for _, obj := range scope.elems { + if alt := pkg.scope.Lookup(obj.Name()); alt != nil { + if pkg, ok := obj.(*PkgName); ok { + check.errorf(alt.Pos(), "%s already declared through import of %s", alt.Name(), pkg.Imported()) + check.reportAltDecl(pkg) + } else { + check.errorf(alt.Pos(), "%s already declared through dot-import of %s", alt.Name(), obj.Pkg()) + // TODO(gri) dot-imported objects don't have a position; reportAltDecl won't print anything + check.reportAltDecl(obj) + } + } + } + } +} + +// packageObjects typechecks all package objects in objList, but not function bodies. +func (check *Checker) packageObjects(objList []Object) { + // add new methods to already type-checked types (from a prior Checker.Files call) + for _, obj := range objList { + if obj, _ := obj.(*TypeName); obj != nil && obj.typ != nil { + check.addMethodDecls(obj) + } + } + + // pre-allocate space for type declaration paths so that the underlying array is reused + typePath := make([]*TypeName, 0, 8) + + for _, obj := range objList { + check.objDecl(obj, nil, typePath) + } + + // At this point we may have a non-empty check.methods map; this means that not all + // entries were deleted at the end of typeDecl because the respective receiver base + // types were not found. In that case, an error was reported when declaring those + // methods. We can now safely discard this map. + check.methods = nil +} + +// functionBodies typechecks all function bodies. +func (check *Checker) functionBodies() { + for _, f := range check.funcs { + check.funcBody(f.decl, f.name, f.sig, f.body) + } +} + +// unusedImports checks for unused imports. +func (check *Checker) unusedImports() { + // if function bodies are not checked, packages' uses are likely missing - don't check + if check.conf.IgnoreFuncBodies { + return + } + + // spec: "It is illegal (...) to directly import a package without referring to + // any of its exported identifiers. To import a package solely for its side-effects + // (initialization), use the blank identifier as explicit package name." + + // check use of regular imported packages + for _, scope := range check.pkg.scope.children /* file scopes */ { + for _, obj := range scope.elems { + if obj, ok := obj.(*PkgName); ok { + // Unused "blank imports" are automatically ignored + // since _ identifiers are not entered into scopes. + if !obj.used { + path := obj.imported.path + base := pkgName(path) + if obj.name == base { + check.softErrorf(obj.pos, "%q imported but not used", path) + } else { + check.softErrorf(obj.pos, "%q imported but not used as %s", path, obj.name) + } + } + } + } + } + + // check use of dot-imported packages + for _, unusedDotImports := range check.unusedDotImports { + for pkg, pos := range unusedDotImports { + check.softErrorf(pos, "%q imported but not used", pkg.path) + } + } +} + +// pkgName returns the package name (last element) of an import path. +func pkgName(path string) string { + if i := strings.LastIndex(path, "/"); i >= 0 { + path = path[i+1:] + } + return path +} + +// dir makes a good-faith attempt to return the directory +// portion of path. If path is empty, the result is ".". +// (Per the go/build package dependency tests, we cannot import +// path/filepath and simply use filepath.Dir.) +func dir(path string) string { + if i := strings.LastIndexAny(path, `/\`); i > 0 { + return path[:i] + } + // i <= 0 + return "." +} diff --git a/third_party/forked/golang/go/types/return.go b/third_party/forked/golang/go/types/return.go new file mode 100644 index 00000000000..0c1447f89b3 --- /dev/null +++ b/third_party/forked/golang/go/types/return.go @@ -0,0 +1,190 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements isTerminating. + +package types + +import ( + "go/ast" + "go/token" +) + +// isTerminating reports if s is a terminating statement. +// If s is labeled, label is the label name; otherwise s +// is "". +func (check *Checker) isTerminating(s ast.Stmt, label string) bool { + switch s := s.(type) { + default: + unreachable() + + case *ast.BadStmt, *ast.DeclStmt, *ast.EmptyStmt, *ast.SendStmt, + *ast.IncDecStmt, *ast.AssignStmt, *ast.GoStmt, *ast.DeferStmt, + *ast.RangeStmt: + // no chance + + case *ast.LabeledStmt: + return check.isTerminating(s.Stmt, s.Label.Name) + + case *ast.ExprStmt: + // the predeclared (possibly parenthesized) panic() function is terminating + if call, _ := unparen(s.X).(*ast.CallExpr); call != nil { + if id, _ := call.Fun.(*ast.Ident); id != nil { + if _, obj := check.scope.LookupParent(id.Name, token.NoPos); obj != nil { + if b, _ := obj.(*Builtin); b != nil && b.id == _Panic { + return true + } + } + } + } + + case *ast.ReturnStmt: + return true + + case *ast.BranchStmt: + if s.Tok == token.GOTO || s.Tok == token.FALLTHROUGH { + return true + } + + case *ast.BlockStmt: + return check.isTerminatingList(s.List, "") + + case *ast.IfStmt: + if s.Else != nil && + check.isTerminating(s.Body, "") && + check.isTerminating(s.Else, "") { + return true + } + + case *ast.SwitchStmt: + return check.isTerminatingSwitch(s.Body, label) + + case *ast.TypeSwitchStmt: + return check.isTerminatingSwitch(s.Body, label) + + case *ast.SelectStmt: + for _, s := range s.Body.List { + cc := s.(*ast.CommClause) + if !check.isTerminatingList(cc.Body, "") || hasBreakList(cc.Body, label, true) { + return false + } + + } + return true + + case *ast.ForStmt: + if s.Cond == nil && !hasBreak(s.Body, label, true) { + return true + } + } + + return false +} + +func (check *Checker) isTerminatingList(list []ast.Stmt, label string) bool { + // trailing empty statements are permitted - skip them + for i := len(list) - 1; i >= 0; i-- { + if _, ok := list[i].(*ast.EmptyStmt); !ok { + return check.isTerminating(list[i], label) + } + } + return false // all statements are empty +} + +func (check *Checker) isTerminatingSwitch(body *ast.BlockStmt, label string) bool { + hasDefault := false + for _, s := range body.List { + cc := s.(*ast.CaseClause) + if cc.List == nil { + hasDefault = true + } + if !check.isTerminatingList(cc.Body, "") || hasBreakList(cc.Body, label, true) { + return false + } + } + return hasDefault +} + +// TODO(gri) For nested breakable statements, the current implementation of hasBreak +// will traverse the same subtree repeatedly, once for each label. Replace +// with a single-pass label/break matching phase. + +// hasBreak reports if s is or contains a break statement +// referring to the label-ed statement or implicit-ly the +// closest outer breakable statement. +func hasBreak(s ast.Stmt, label string, implicit bool) bool { + switch s := s.(type) { + default: + unreachable() + + case *ast.BadStmt, *ast.DeclStmt, *ast.EmptyStmt, *ast.ExprStmt, + *ast.SendStmt, *ast.IncDecStmt, *ast.AssignStmt, *ast.GoStmt, + *ast.DeferStmt, *ast.ReturnStmt: + // no chance + + case *ast.LabeledStmt: + return hasBreak(s.Stmt, label, implicit) + + case *ast.BranchStmt: + if s.Tok == token.BREAK { + if s.Label == nil { + return implicit + } + if s.Label.Name == label { + return true + } + } + + case *ast.BlockStmt: + return hasBreakList(s.List, label, implicit) + + case *ast.IfStmt: + if hasBreak(s.Body, label, implicit) || + s.Else != nil && hasBreak(s.Else, label, implicit) { + return true + } + + case *ast.CaseClause: + return hasBreakList(s.Body, label, implicit) + + case *ast.SwitchStmt: + if label != "" && hasBreak(s.Body, label, false) { + return true + } + + case *ast.TypeSwitchStmt: + if label != "" && hasBreak(s.Body, label, false) { + return true + } + + case *ast.CommClause: + return hasBreakList(s.Body, label, implicit) + + case *ast.SelectStmt: + if label != "" && hasBreak(s.Body, label, false) { + return true + } + + case *ast.ForStmt: + if label != "" && hasBreak(s.Body, label, false) { + return true + } + + case *ast.RangeStmt: + if label != "" && hasBreak(s.Body, label, false) { + return true + } + } + + return false +} + +func hasBreakList(list []ast.Stmt, label string, implicit bool) bool { + for _, s := range list { + if hasBreak(s, label, implicit) { + return true + } + } + return false +} diff --git a/third_party/forked/golang/go/types/scope.go b/third_party/forked/golang/go/types/scope.go new file mode 100644 index 00000000000..39e42d758ad --- /dev/null +++ b/third_party/forked/golang/go/types/scope.go @@ -0,0 +1,191 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements Scopes. + +package types + +import ( + "bytes" + "fmt" + "go/token" + "io" + "sort" + "strings" +) + +// TODO(gri) Provide scopes with a name or other mechanism so that +// objects can use that information for better printing. + +// A Scope maintains a set of objects and links to its containing +// (parent) and contained (children) scopes. Objects may be inserted +// and looked up by name. The zero value for Scope is a ready-to-use +// empty scope. +type Scope struct { + parent *Scope + children []*Scope + elems map[string]Object // lazily allocated + pos, end token.Pos // scope extent; may be invalid + comment string // for debugging only + isFunc bool // set if this is a function scope (internal use only) +} + +// NewScope returns a new, empty scope contained in the given parent +// scope, if any. The comment is for debugging only. +func NewScope(parent *Scope, pos, end token.Pos, comment string) *Scope { + s := &Scope{parent, nil, nil, pos, end, comment, false} + // don't add children to Universe scope! + if parent != nil && parent != Universe { + parent.children = append(parent.children, s) + } + return s +} + +// Parent returns the scope's containing (parent) scope. +func (s *Scope) Parent() *Scope { return s.parent } + +// Len() returns the number of scope elements. +func (s *Scope) Len() int { return len(s.elems) } + +// Names returns the scope's element names in sorted order. +func (s *Scope) Names() []string { + names := make([]string, len(s.elems)) + i := 0 + for name := range s.elems { + names[i] = name + i++ + } + sort.Strings(names) + return names +} + +// NumChildren() returns the number of scopes nested in s. +func (s *Scope) NumChildren() int { return len(s.children) } + +// Child returns the i'th child scope for 0 <= i < NumChildren(). +func (s *Scope) Child(i int) *Scope { return s.children[i] } + +// Lookup returns the object in scope s with the given name if such an +// object exists; otherwise the result is nil. +func (s *Scope) Lookup(name string) Object { + return s.elems[name] +} + +// LookupParent follows the parent chain of scopes starting with s until +// it finds a scope where Lookup(name) returns a non-nil object, and then +// returns that scope and object. If a valid position pos is provided, +// only objects that were declared at or before pos are considered. +// If no such scope and object exists, the result is (nil, nil). +// +// Note that obj.Parent() may be different from the returned scope if the +// object was inserted into the scope and already had a parent at that +// time (see Insert, below). This can only happen for dot-imported objects +// whose scope is the scope of the package that exported them. +func (s *Scope) LookupParent(name string, pos token.Pos) (*Scope, Object) { + for ; s != nil; s = s.parent { + if obj := s.elems[name]; obj != nil && (!pos.IsValid() || obj.scopePos() <= pos) { + return s, obj + } + } + return nil, nil +} + +// Insert attempts to insert an object obj into scope s. +// If s already contains an alternative object alt with +// the same name, Insert leaves s unchanged and returns alt. +// Otherwise it inserts obj, sets the object's parent scope +// if not already set, and returns nil. +func (s *Scope) Insert(obj Object) Object { + name := obj.Name() + if alt := s.elems[name]; alt != nil { + return alt + } + if s.elems == nil { + s.elems = make(map[string]Object) + } + s.elems[name] = obj + if obj.Parent() == nil { + obj.setParent(s) + } + return nil +} + +// Pos and End describe the scope's source code extent [pos, end). +// The results are guaranteed to be valid only if the type-checked +// AST has complete position information. The extent is undefined +// for Universe and package scopes. +func (s *Scope) Pos() token.Pos { return s.pos } +func (s *Scope) End() token.Pos { return s.end } + +// Contains returns true if pos is within the scope's extent. +// The result is guaranteed to be valid only if the type-checked +// AST has complete position information. +func (s *Scope) Contains(pos token.Pos) bool { + return s.pos <= pos && pos < s.end +} + +// Innermost returns the innermost (child) scope containing +// pos. If pos is not within any scope, the result is nil. +// The result is also nil for the Universe scope. +// The result is guaranteed to be valid only if the type-checked +// AST has complete position information. +func (s *Scope) Innermost(pos token.Pos) *Scope { + // Package scopes do not have extents since they may be + // discontiguous, so iterate over the package's files. + if s.parent == Universe { + for _, s := range s.children { + if inner := s.Innermost(pos); inner != nil { + return inner + } + } + } + + if s.Contains(pos) { + for _, s := range s.children { + if s.Contains(pos) { + return s.Innermost(pos) + } + } + return s + } + return nil +} + +// WriteTo writes a string representation of the scope to w, +// with the scope elements sorted by name. +// The level of indentation is controlled by n >= 0, with +// n == 0 for no indentation. +// If recurse is set, it also writes nested (children) scopes. +func (s *Scope) WriteTo(w io.Writer, n int, recurse bool) { + const ind = ". " + indn := strings.Repeat(ind, n) + + fmt.Fprintf(w, "%s%s scope %p {", indn, s.comment, s) + if len(s.elems) == 0 { + fmt.Fprintf(w, "}\n") + return + } + + fmt.Fprintln(w) + indn1 := indn + ind + for _, name := range s.Names() { + fmt.Fprintf(w, "%s%s\n", indn1, s.elems[name]) + } + + if recurse { + for _, s := range s.children { + fmt.Fprintln(w) + s.WriteTo(w, n+1, recurse) + } + } + + fmt.Fprintf(w, "%s}", indn) +} + +// String returns a string representation of the scope, for debugging. +func (s *Scope) String() string { + var buf bytes.Buffer + s.WriteTo(&buf, 0, false) + return buf.String() +} diff --git a/third_party/forked/golang/go/types/selection.go b/third_party/forked/golang/go/types/selection.go new file mode 100644 index 00000000000..124e0d39f02 --- /dev/null +++ b/third_party/forked/golang/go/types/selection.go @@ -0,0 +1,143 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements Selections. + +package types + +import ( + "bytes" + "fmt" +) + +// SelectionKind describes the kind of a selector expression x.f +// (excluding qualified identifiers). +type SelectionKind int + +const ( + FieldVal SelectionKind = iota // x.f is a struct field selector + MethodVal // x.f is a method selector + MethodExpr // x.f is a method expression +) + +// A Selection describes a selector expression x.f. +// For the declarations: +// +// type T struct{ x int; E } +// type E struct{} +// func (e E) m() {} +// var p *T +// +// the following relations exist: +// +// Selector Kind Recv Obj Type Index Indirect +// +// p.x FieldVal T x int {0} true +// p.m MethodVal *T m func (e *T) m() {1, 0} true +// T.m MethodExpr T m func m(_ T) {1, 0} false +// +type Selection struct { + kind SelectionKind + recv Type // type of x + obj Object // object denoted by x.f + index []int // path from x to x.f + indirect bool // set if there was any pointer indirection on the path +} + +// Kind returns the selection kind. +func (s *Selection) Kind() SelectionKind { return s.kind } + +// Recv returns the type of x in x.f. +func (s *Selection) Recv() Type { return s.recv } + +// Obj returns the object denoted by x.f; a *Var for +// a field selection, and a *Func in all other cases. +func (s *Selection) Obj() Object { return s.obj } + +// Type returns the type of x.f, which may be different from the type of f. +// See Selection for more information. +func (s *Selection) Type() Type { + switch s.kind { + case MethodVal: + // The type of x.f is a method with its receiver type set + // to the type of x. + sig := *s.obj.(*Func).typ.(*Signature) + recv := *sig.recv + recv.typ = s.recv + sig.recv = &recv + return &sig + + case MethodExpr: + // The type of x.f is a function (without receiver) + // and an additional first argument with the same type as x. + // TODO(gri) Similar code is already in call.go - factor! + // TODO(gri) Compute this eagerly to avoid allocations. + sig := *s.obj.(*Func).typ.(*Signature) + arg0 := *sig.recv + sig.recv = nil + arg0.typ = s.recv + var params []*Var + if sig.params != nil { + params = sig.params.vars + } + sig.params = NewTuple(append([]*Var{&arg0}, params...)...) + return &sig + } + + // In all other cases, the type of x.f is the type of x. + return s.obj.Type() +} + +// Index describes the path from x to f in x.f. +// The last index entry is the field or method index of the type declaring f; +// either: +// +// 1) the list of declared methods of a named type; or +// 2) the list of methods of an interface type; or +// 3) the list of fields of a struct type. +// +// The earlier index entries are the indices of the embedded fields implicitly +// traversed to get from (the type of) x to f, starting at embedding depth 0. +func (s *Selection) Index() []int { return s.index } + +// Indirect reports whether any pointer indirection was required to get from +// x to f in x.f. +func (s *Selection) Indirect() bool { return s.indirect } + +func (s *Selection) String() string { return SelectionString(s, nil) } + +// SelectionString returns the string form of s. +// The Qualifier controls the printing of +// package-level objects, and may be nil. +// +// Examples: +// "field (T) f int" +// "method (T) f(X) Y" +// "method expr (T) f(X) Y" +// +func SelectionString(s *Selection, qf Qualifier) string { + var k string + switch s.kind { + case FieldVal: + k = "field " + case MethodVal: + k = "method " + case MethodExpr: + k = "method expr " + default: + unreachable() + } + var buf bytes.Buffer + buf.WriteString(k) + buf.WriteByte('(') + WriteType(&buf, s.Recv(), qf) + fmt.Fprintf(&buf, ") %s", s.obj.Name()) + if T := s.Type(); s.kind == FieldVal { + buf.WriteByte(' ') + WriteType(&buf, T, qf) + } else { + WriteSignature(&buf, T.(*Signature), qf) + } + return buf.String() +} diff --git a/third_party/forked/golang/go/types/sizes.go b/third_party/forked/golang/go/types/sizes.go new file mode 100644 index 00000000000..eb274799f42 --- /dev/null +++ b/third_party/forked/golang/go/types/sizes.go @@ -0,0 +1,254 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements Sizes. + +package types + +// Sizes defines the sizing functions for package unsafe. +type Sizes interface { + // Alignof returns the alignment of a variable of type T. + // Alignof must implement the alignment guarantees required by the spec. + Alignof(T Type) int64 + + // Offsetsof returns the offsets of the given struct fields, in bytes. + // Offsetsof must implement the offset guarantees required by the spec. + Offsetsof(fields []*Var) []int64 + + // Sizeof returns the size of a variable of type T. + // Sizeof must implement the size guarantees required by the spec. + Sizeof(T Type) int64 +} + +// StdSizes is a convenience type for creating commonly used Sizes. +// It makes the following simplifying assumptions: +// +// - The size of explicitly sized basic types (int16, etc.) is the +// specified size. +// - The size of strings and interfaces is 2*WordSize. +// - The size of slices is 3*WordSize. +// - The size of an array of n elements corresponds to the size of +// a struct of n consecutive fields of the array's element type. +// - The size of a struct is the offset of the last field plus that +// field's size. As with all element types, if the struct is used +// in an array its size must first be aligned to a multiple of the +// struct's alignment. +// - All other types have size WordSize. +// - Arrays and structs are aligned per spec definition; all other +// types are naturally aligned with a maximum alignment MaxAlign. +// +// *StdSizes implements Sizes. +// +type StdSizes struct { + WordSize int64 // word size in bytes - must be >= 4 (32bits) + MaxAlign int64 // maximum alignment in bytes - must be >= 1 +} + +func (s *StdSizes) Alignof(T Type) int64 { + // For arrays and structs, alignment is defined in terms + // of alignment of the elements and fields, respectively. + switch t := T.Underlying().(type) { + case *Array: + // spec: "For a variable x of array type: unsafe.Alignof(x) + // is the same as unsafe.Alignof(x[0]), but at least 1." + return s.Alignof(t.elem) + case *Struct: + // spec: "For a variable x of struct type: unsafe.Alignof(x) + // is the largest of the values unsafe.Alignof(x.f) for each + // field f of x, but at least 1." + max := int64(1) + for _, f := range t.fields { + if a := s.Alignof(f.typ); a > max { + max = a + } + } + return max + case *Slice, *Interface: + // Multiword data structures are effectively structs + // in which each element has size WordSize. + return s.WordSize + case *Basic: + // Strings are like slices and interfaces. + if t.Info()&IsString != 0 { + return s.WordSize + } + } + a := s.Sizeof(T) // may be 0 + // spec: "For a variable x of any type: unsafe.Alignof(x) is at least 1." + if a < 1 { + return 1 + } + // complex{64,128} are aligned like [2]float{32,64}. + if isComplex(T) { + a /= 2 + } + if a > s.MaxAlign { + return s.MaxAlign + } + return a +} + +func (s *StdSizes) Offsetsof(fields []*Var) []int64 { + offsets := make([]int64, len(fields)) + var o int64 + for i, f := range fields { + a := s.Alignof(f.typ) + o = align(o, a) + offsets[i] = o + o += s.Sizeof(f.typ) + } + return offsets +} + +var basicSizes = [...]byte{ + Bool: 1, + Int8: 1, + Int16: 2, + Int32: 4, + Int64: 8, + Uint8: 1, + Uint16: 2, + Uint32: 4, + Uint64: 8, + Float32: 4, + Float64: 8, + Complex64: 8, + Complex128: 16, +} + +func (s *StdSizes) Sizeof(T Type) int64 { + switch t := T.Underlying().(type) { + case *Basic: + assert(isTyped(T)) + k := t.kind + if int(k) < len(basicSizes) { + if s := basicSizes[k]; s > 0 { + return int64(s) + } + } + if k == String { + return s.WordSize * 2 + } + case *Array: + n := t.len + if n <= 0 { + return 0 + } + // n > 0 + a := s.Alignof(t.elem) + z := s.Sizeof(t.elem) + return align(z, a)*(n-1) + z + case *Slice: + return s.WordSize * 3 + case *Struct: + n := t.NumFields() + if n == 0 { + return 0 + } + offsets := s.Offsetsof(t.fields) + return offsets[n-1] + s.Sizeof(t.fields[n-1].typ) + case *Interface: + return s.WordSize * 2 + } + return s.WordSize // catch-all +} + +// common architecture word sizes and alignments +var gcArchSizes = map[string]*StdSizes{ + "386": {4, 4}, + "arm": {4, 4}, + "arm64": {8, 8}, + "amd64": {8, 8}, + "amd64p32": {4, 8}, + "mips": {4, 4}, + "mipsle": {4, 4}, + "mips64": {8, 8}, + "mips64le": {8, 8}, + "ppc64": {8, 8}, + "ppc64le": {8, 8}, + "s390x": {8, 8}, + // When adding more architectures here, + // update the doc string of SizesFor below. +} + +// SizesFor returns the Sizes used by a compiler for an architecture. +// The result is nil if a compiler/architecture pair is not known. +// +// Supported architectures for compiler "gc": +// "386", "arm", "arm64", "amd64", "amd64p32", "mips", "mipsle", +// "mips64", "mips64le", "ppc64", "ppc64le", "s390x". +func SizesFor(compiler, arch string) Sizes { + if compiler != "gc" { + return nil + } + s, ok := gcArchSizes[arch] + if !ok { + return nil + } + return s +} + +// stdSizes is used if Config.Sizes == nil. +var stdSizes = SizesFor("gc", "amd64") + +func (conf *Config) alignof(T Type) int64 { + if s := conf.Sizes; s != nil { + if a := s.Alignof(T); a >= 1 { + return a + } + panic("Config.Sizes.Alignof returned an alignment < 1") + } + return stdSizes.Alignof(T) +} + +func (conf *Config) offsetsof(T *Struct) []int64 { + var offsets []int64 + if T.NumFields() > 0 { + // compute offsets on demand + if s := conf.Sizes; s != nil { + offsets = s.Offsetsof(T.fields) + // sanity checks + if len(offsets) != T.NumFields() { + panic("Config.Sizes.Offsetsof returned the wrong number of offsets") + } + for _, o := range offsets { + if o < 0 { + panic("Config.Sizes.Offsetsof returned an offset < 0") + } + } + } else { + offsets = stdSizes.Offsetsof(T.fields) + } + } + return offsets +} + +// offsetof returns the offset of the field specified via +// the index sequence relative to typ. All embedded fields +// must be structs (rather than pointer to structs). +func (conf *Config) offsetof(typ Type, index []int) int64 { + var o int64 + for _, i := range index { + s := typ.Underlying().(*Struct) + o += conf.offsetsof(s)[i] + typ = s.fields[i].typ + } + return o +} + +func (conf *Config) sizeof(T Type) int64 { + if s := conf.Sizes; s != nil { + if z := s.Sizeof(T); z >= 0 { + return z + } + panic("Config.Sizes.Sizeof returned a size < 0") + } + return stdSizes.Sizeof(T) +} + +// align returns the smallest y >= x such that y % a == 0. +func align(x, a int64) int64 { + y := x + a - 1 + return y - y%a +} diff --git a/third_party/forked/golang/go/types/stmt.go b/third_party/forked/golang/go/types/stmt.go new file mode 100644 index 00000000000..5221bcc7c12 --- /dev/null +++ b/third_party/forked/golang/go/types/stmt.go @@ -0,0 +1,870 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements typechecking of statements. + +package types + +import ( + "fmt" + "go/ast" + "go/constant" + "go/token" + "sort" +) + +func (check *Checker) funcBody(decl *declInfo, name string, sig *Signature, body *ast.BlockStmt) { + if trace { + if name == "" { + name = "" + } + fmt.Printf("--- %s: %s {\n", name, sig) + defer fmt.Println("--- ") + } + + // set function scope extent + sig.scope.pos = body.Pos() + sig.scope.end = body.End() + + // save/restore current context and setup function context + // (and use 0 indentation at function start) + defer func(ctxt context, indent int) { + check.context = ctxt + check.indent = indent + }(check.context, check.indent) + check.context = context{ + decl: decl, + scope: sig.scope, + sig: sig, + } + check.indent = 0 + + check.stmtList(0, body.List) + + if check.hasLabel { + check.labels(body) + } + + if sig.results.Len() > 0 && !check.isTerminating(body, "") { + check.error(body.Rbrace, "missing return") + } + + // spec: "Implementation restriction: A compiler may make it illegal to + // declare a variable inside a function body if the variable is never used." + // (One could check each scope after use, but that distributes this check + // over several places because CloseScope is not always called explicitly.) + check.usage(sig.scope) +} + +func (check *Checker) usage(scope *Scope) { + var unused []*Var + for _, elem := range scope.elems { + if v, _ := elem.(*Var); v != nil && !v.used { + unused = append(unused, v) + } + } + sort.Slice(unused, func(i, j int) bool { + return unused[i].pos < unused[j].pos + }) + for _, v := range unused { + check.softErrorf(v.pos, "%s declared but not used", v.name) + } + + for _, scope := range scope.children { + // Don't go inside closure scopes a second time; + // they are handled explicitly by funcBody. + if !scope.isFunc { + check.usage(scope) + } + } +} + +// stmtContext is a bitset describing which +// control-flow statements are permissible, +// and provides additional context information +// for better error messages. +type stmtContext uint + +const ( + // permissible control-flow statements + breakOk stmtContext = 1 << iota + continueOk + fallthroughOk + + // additional context information + finalSwitchCase +) + +func (check *Checker) simpleStmt(s ast.Stmt) { + if s != nil { + check.stmt(0, s) + } +} + +func trimTrailingEmptyStmts(list []ast.Stmt) []ast.Stmt { + for i := len(list); i > 0; i-- { + if _, ok := list[i-1].(*ast.EmptyStmt); !ok { + return list[:i] + } + } + return nil +} + +func (check *Checker) stmtList(ctxt stmtContext, list []ast.Stmt) { + ok := ctxt&fallthroughOk != 0 + inner := ctxt &^ fallthroughOk + list = trimTrailingEmptyStmts(list) // trailing empty statements are "invisible" to fallthrough analysis + for i, s := range list { + inner := inner + if ok && i+1 == len(list) { + inner |= fallthroughOk + } + check.stmt(inner, s) + } +} + +func (check *Checker) multipleDefaults(list []ast.Stmt) { + var first ast.Stmt + for _, s := range list { + var d ast.Stmt + switch c := s.(type) { + case *ast.CaseClause: + if len(c.List) == 0 { + d = s + } + case *ast.CommClause: + if c.Comm == nil { + d = s + } + default: + check.invalidAST(s.Pos(), "case/communication clause expected") + } + if d != nil { + if first != nil { + check.errorf(d.Pos(), "multiple defaults (first at %s)", check.fset.Position(first.Pos())) + } else { + first = d + } + } + } +} + +func (check *Checker) openScope(s ast.Stmt, comment string) { + scope := NewScope(check.scope, s.Pos(), s.End(), comment) + check.recordScope(s, scope) + check.scope = scope +} + +func (check *Checker) closeScope() { + check.scope = check.scope.Parent() +} + +func assignOp(op token.Token) token.Token { + // token_test.go verifies the token ordering this function relies on + if token.ADD_ASSIGN <= op && op <= token.AND_NOT_ASSIGN { + return op + (token.ADD - token.ADD_ASSIGN) + } + return token.ILLEGAL +} + +func (check *Checker) suspendedCall(keyword string, call *ast.CallExpr) { + var x operand + var msg string + switch check.rawExpr(&x, call, nil) { + case conversion: + msg = "requires function call, not conversion" + case expression: + msg = "discards result of" + case statement: + return + default: + unreachable() + } + check.errorf(x.pos(), "%s %s %s", keyword, msg, &x) +} + +// goVal returns the Go value for val, or nil. +func goVal(val constant.Value) interface{} { + // val should exist, but be conservative and check + if val == nil { + return nil + } + // Match implementation restriction of other compilers. + // gc only checks duplicates for integer, floating-point + // and string values, so only create Go values for these + // types. + switch val.Kind() { + case constant.Int: + if x, ok := constant.Int64Val(val); ok { + return x + } + if x, ok := constant.Uint64Val(val); ok { + return x + } + case constant.Float: + if x, ok := constant.Float64Val(val); ok { + return x + } + case constant.String: + return constant.StringVal(val) + } + return nil +} + +// A valueMap maps a case value (of a basic Go type) to a list of positions +// where the same case value appeared, together with the corresponding case +// types. +// Since two case values may have the same "underlying" value but different +// types we need to also check the value's types (e.g., byte(1) vs myByte(1)) +// when the switch expression is of interface type. +type ( + valueMap map[interface{}][]valueType // underlying Go value -> valueType + valueType struct { + pos token.Pos + typ Type + } +) + +func (check *Checker) caseValues(x *operand, values []ast.Expr, seen valueMap) { +L: + for _, e := range values { + var v operand + check.expr(&v, e) + if x.mode == invalid || v.mode == invalid { + continue L + } + check.convertUntyped(&v, x.typ) + if v.mode == invalid { + continue L + } + // Order matters: By comparing v against x, error positions are at the case values. + res := v // keep original v unchanged + check.comparison(&res, x, token.EQL) + if res.mode == invalid { + continue L + } + if v.mode != constant_ { + continue L // we're done + } + // look for duplicate values + if val := goVal(v.val); val != nil { + // look for duplicate types for a given value + // (quadratic algorithm, but these lists tend to be very short) + for _, vt := range seen[val] { + if Identical(v.typ, vt.typ) { + check.errorf(v.pos(), "duplicate case %s in expression switch", &v) + check.error(vt.pos, "\tprevious case") // secondary error, \t indented + continue L + } + } + seen[val] = append(seen[val], valueType{v.pos(), v.typ}) + } + } +} + +func (check *Checker) caseTypes(x *operand, xtyp *Interface, types []ast.Expr, seen map[Type]token.Pos) (T Type) { +L: + for _, e := range types { + T = check.typOrNil(e) + if T == Typ[Invalid] { + continue L + } + // look for duplicate types + // (quadratic algorithm, but type switches tend to be reasonably small) + for t, pos := range seen { + if T == nil && t == nil || T != nil && t != nil && Identical(T, t) { + // talk about "case" rather than "type" because of nil case + Ts := "nil" + if T != nil { + Ts = T.String() + } + check.errorf(e.Pos(), "duplicate case %s in type switch", Ts) + check.error(pos, "\tprevious case") // secondary error, \t indented + continue L + } + } + seen[T] = e.Pos() + if T != nil { + check.typeAssertion(e.Pos(), x, xtyp, T) + } + } + return +} + +// stmt typechecks statement s. +func (check *Checker) stmt(ctxt stmtContext, s ast.Stmt) { + // statements cannot use iota in general + // (constant declarations set it explicitly) + assert(check.iota == nil) + + // statements must end with the same top scope as they started with + if debug { + defer func(scope *Scope) { + // don't check if code is panicking + if p := recover(); p != nil { + panic(p) + } + assert(scope == check.scope) + }(check.scope) + } + + inner := ctxt &^ (fallthroughOk | finalSwitchCase) + switch s := s.(type) { + case *ast.BadStmt, *ast.EmptyStmt: + // ignore + + case *ast.DeclStmt: + check.declStmt(s.Decl) + + case *ast.LabeledStmt: + check.hasLabel = true + check.stmt(ctxt, s.Stmt) + + case *ast.ExprStmt: + // spec: "With the exception of specific built-in functions, + // function and method calls and receive operations can appear + // in statement context. Such statements may be parenthesized." + var x operand + kind := check.rawExpr(&x, s.X, nil) + var msg string + switch x.mode { + default: + if kind == statement { + return + } + msg = "is not used" + case builtin: + msg = "must be called" + case typexpr: + msg = "is not an expression" + } + check.errorf(x.pos(), "%s %s", &x, msg) + + case *ast.SendStmt: + var ch, x operand + check.expr(&ch, s.Chan) + check.expr(&x, s.Value) + if ch.mode == invalid || x.mode == invalid { + return + } + + tch, ok := ch.typ.Underlying().(*Chan) + if !ok { + check.invalidOp(s.Arrow, "cannot send to non-chan type %s", ch.typ) + return + } + + if tch.dir == RecvOnly { + check.invalidOp(s.Arrow, "cannot send to receive-only type %s", tch) + return + } + + check.assignment(&x, tch.elem, "send") + + case *ast.IncDecStmt: + var op token.Token + switch s.Tok { + case token.INC: + op = token.ADD + case token.DEC: + op = token.SUB + default: + check.invalidAST(s.TokPos, "unknown inc/dec operation %s", s.Tok) + return + } + + var x operand + check.expr(&x, s.X) + if x.mode == invalid { + return + } + if !isNumeric(x.typ) { + check.invalidOp(s.X.Pos(), "%s%s (non-numeric type %s)", s.X, s.Tok, x.typ) + return + } + + Y := &ast.BasicLit{ValuePos: s.X.Pos(), Kind: token.INT, Value: "1"} // use x's position + check.binary(&x, nil, s.X, Y, op) + if x.mode == invalid { + return + } + check.assignVar(s.X, &x) + + case *ast.AssignStmt: + switch s.Tok { + case token.ASSIGN, token.DEFINE: + if len(s.Lhs) == 0 { + check.invalidAST(s.Pos(), "missing lhs in assignment") + return + } + if s.Tok == token.DEFINE { + check.shortVarDecl(s.TokPos, s.Lhs, s.Rhs) + } else { + // regular assignment + check.assignVars(s.Lhs, s.Rhs) + } + + default: + // assignment operations + if len(s.Lhs) != 1 || len(s.Rhs) != 1 { + check.errorf(s.TokPos, "assignment operation %s requires single-valued expressions", s.Tok) + return + } + op := assignOp(s.Tok) + if op == token.ILLEGAL { + check.invalidAST(s.TokPos, "unknown assignment operation %s", s.Tok) + return + } + var x operand + check.binary(&x, nil, s.Lhs[0], s.Rhs[0], op) + if x.mode == invalid { + return + } + check.assignVar(s.Lhs[0], &x) + } + + case *ast.GoStmt: + check.suspendedCall("go", s.Call) + + case *ast.DeferStmt: + check.suspendedCall("defer", s.Call) + + case *ast.ReturnStmt: + res := check.sig.results + if res.Len() > 0 { + // function returns results + // (if one, say the first, result parameter is named, all of them are named) + if len(s.Results) == 0 && res.vars[0].name != "" { + // spec: "Implementation restriction: A compiler may disallow an empty expression + // list in a "return" statement if a different entity (constant, type, or variable) + // with the same name as a result parameter is in scope at the place of the return." + for _, obj := range res.vars { + if _, alt := check.scope.LookupParent(obj.name, check.pos); alt != nil && alt != obj { + check.errorf(s.Pos(), "result parameter %s not in scope at return", obj.name) + check.errorf(alt.Pos(), "\tinner declaration of %s", obj) + // ok to continue + } + } + } else { + // return has results or result parameters are unnamed + check.initVars(res.vars, s.Results, s.Return) + } + } else if len(s.Results) > 0 { + check.error(s.Results[0].Pos(), "no result values expected") + check.use(s.Results...) + } + + case *ast.BranchStmt: + if s.Label != nil { + check.hasLabel = true + return // checked in 2nd pass (check.labels) + } + switch s.Tok { + case token.BREAK: + if ctxt&breakOk == 0 { + check.error(s.Pos(), "break not in for, switch, or select statement") + } + case token.CONTINUE: + if ctxt&continueOk == 0 { + check.error(s.Pos(), "continue not in for statement") + } + case token.FALLTHROUGH: + if ctxt&fallthroughOk == 0 { + msg := "fallthrough statement out of place" + if ctxt&finalSwitchCase != 0 { + msg = "cannot fallthrough final case in switch" + } + check.error(s.Pos(), msg) + } + default: + check.invalidAST(s.Pos(), "branch statement: %s", s.Tok) + } + + case *ast.BlockStmt: + check.openScope(s, "block") + defer check.closeScope() + + check.stmtList(inner, s.List) + + case *ast.IfStmt: + check.openScope(s, "if") + defer check.closeScope() + + check.simpleStmt(s.Init) + var x operand + check.expr(&x, s.Cond) + if x.mode != invalid && !isBoolean(x.typ) { + check.error(s.Cond.Pos(), "non-boolean condition in if statement") + } + check.stmt(inner, s.Body) + // The parser produces a correct AST but if it was modified + // elsewhere the else branch may be invalid. Check again. + switch s.Else.(type) { + case nil, *ast.BadStmt: + // valid or error already reported + case *ast.IfStmt, *ast.BlockStmt: + check.stmt(inner, s.Else) + default: + check.error(s.Else.Pos(), "invalid else branch in if statement") + } + + case *ast.SwitchStmt: + inner |= breakOk + check.openScope(s, "switch") + defer check.closeScope() + + check.simpleStmt(s.Init) + var x operand + if s.Tag != nil { + check.expr(&x, s.Tag) + // By checking assignment of x to an invisible temporary + // (as a compiler would), we get all the relevant checks. + check.assignment(&x, nil, "switch expression") + } else { + // spec: "A missing switch expression is + // equivalent to the boolean value true." + x.mode = constant_ + x.typ = Typ[Bool] + x.val = constant.MakeBool(true) + x.expr = &ast.Ident{NamePos: s.Body.Lbrace, Name: "true"} + } + + check.multipleDefaults(s.Body.List) + + seen := make(valueMap) // map of seen case values to positions and types + for i, c := range s.Body.List { + clause, _ := c.(*ast.CaseClause) + if clause == nil { + check.invalidAST(c.Pos(), "incorrect expression switch case") + continue + } + check.caseValues(&x, clause.List, seen) + check.openScope(clause, "case") + inner := inner + if i+1 < len(s.Body.List) { + inner |= fallthroughOk + } else { + inner |= finalSwitchCase + } + check.stmtList(inner, clause.Body) + check.closeScope() + } + + case *ast.TypeSwitchStmt: + inner |= breakOk + check.openScope(s, "type switch") + defer check.closeScope() + + check.simpleStmt(s.Init) + + // A type switch guard must be of the form: + // + // TypeSwitchGuard = [ identifier ":=" ] PrimaryExpr "." "(" "type" ")" . + // + // The parser is checking syntactic correctness; + // remaining syntactic errors are considered AST errors here. + // TODO(gri) better factoring of error handling (invalid ASTs) + // + var lhs *ast.Ident // lhs identifier or nil + var rhs ast.Expr + switch guard := s.Assign.(type) { + case *ast.ExprStmt: + rhs = guard.X + case *ast.AssignStmt: + if len(guard.Lhs) != 1 || guard.Tok != token.DEFINE || len(guard.Rhs) != 1 { + check.invalidAST(s.Pos(), "incorrect form of type switch guard") + return + } + + lhs, _ = guard.Lhs[0].(*ast.Ident) + if lhs == nil { + check.invalidAST(s.Pos(), "incorrect form of type switch guard") + return + } + + if lhs.Name == "_" { + // _ := x.(type) is an invalid short variable declaration + check.softErrorf(lhs.Pos(), "no new variable on left side of :=") + lhs = nil // avoid declared but not used error below + } else { + check.recordDef(lhs, nil) // lhs variable is implicitly declared in each cause clause + } + + rhs = guard.Rhs[0] + + default: + check.invalidAST(s.Pos(), "incorrect form of type switch guard") + return + } + + // rhs must be of the form: expr.(type) and expr must be an interface + expr, _ := rhs.(*ast.TypeAssertExpr) + if expr == nil || expr.Type != nil { + check.invalidAST(s.Pos(), "incorrect form of type switch guard") + return + } + var x operand + check.expr(&x, expr.X) + if x.mode == invalid { + return + } + xtyp, _ := x.typ.Underlying().(*Interface) + if xtyp == nil { + check.errorf(x.pos(), "%s is not an interface", &x) + return + } + + check.multipleDefaults(s.Body.List) + + var lhsVars []*Var // list of implicitly declared lhs variables + seen := make(map[Type]token.Pos) // map of seen types to positions + for _, s := range s.Body.List { + clause, _ := s.(*ast.CaseClause) + if clause == nil { + check.invalidAST(s.Pos(), "incorrect type switch case") + continue + } + // Check each type in this type switch case. + T := check.caseTypes(&x, xtyp, clause.List, seen) + check.openScope(clause, "case") + // If lhs exists, declare a corresponding variable in the case-local scope. + if lhs != nil { + // spec: "The TypeSwitchGuard may include a short variable declaration. + // When that form is used, the variable is declared at the beginning of + // the implicit block in each clause. In clauses with a case listing + // exactly one type, the variable has that type; otherwise, the variable + // has the type of the expression in the TypeSwitchGuard." + if len(clause.List) != 1 || T == nil { + T = x.typ + } + obj := NewVar(lhs.Pos(), check.pkg, lhs.Name, T) + scopePos := clause.Pos() + token.Pos(len("default")) // for default clause (len(List) == 0) + if n := len(clause.List); n > 0 { + scopePos = clause.List[n-1].End() + } + check.declare(check.scope, nil, obj, scopePos) + check.recordImplicit(clause, obj) + // For the "declared but not used" error, all lhs variables act as + // one; i.e., if any one of them is 'used', all of them are 'used'. + // Collect them for later analysis. + lhsVars = append(lhsVars, obj) + } + check.stmtList(inner, clause.Body) + check.closeScope() + } + + // If lhs exists, we must have at least one lhs variable that was used. + if lhs != nil { + var used bool + for _, v := range lhsVars { + if v.used { + used = true + } + v.used = true // avoid usage error when checking entire function + } + if !used { + check.softErrorf(lhs.Pos(), "%s declared but not used", lhs.Name) + } + } + + case *ast.SelectStmt: + inner |= breakOk + + check.multipleDefaults(s.Body.List) + + for _, s := range s.Body.List { + clause, _ := s.(*ast.CommClause) + if clause == nil { + continue // error reported before + } + + // clause.Comm must be a SendStmt, RecvStmt, or default case + valid := false + var rhs ast.Expr // rhs of RecvStmt, or nil + switch s := clause.Comm.(type) { + case nil, *ast.SendStmt: + valid = true + case *ast.AssignStmt: + if len(s.Rhs) == 1 { + rhs = s.Rhs[0] + } + case *ast.ExprStmt: + rhs = s.X + } + + // if present, rhs must be a receive operation + if rhs != nil { + if x, _ := unparen(rhs).(*ast.UnaryExpr); x != nil && x.Op == token.ARROW { + valid = true + } + } + + if !valid { + check.error(clause.Comm.Pos(), "select case must be send or receive (possibly with assignment)") + continue + } + + check.openScope(s, "case") + if clause.Comm != nil { + check.stmt(inner, clause.Comm) + } + check.stmtList(inner, clause.Body) + check.closeScope() + } + + case *ast.ForStmt: + inner |= breakOk | continueOk + check.openScope(s, "for") + defer check.closeScope() + + check.simpleStmt(s.Init) + if s.Cond != nil { + var x operand + check.expr(&x, s.Cond) + if x.mode != invalid && !isBoolean(x.typ) { + check.error(s.Cond.Pos(), "non-boolean condition in for statement") + } + } + check.simpleStmt(s.Post) + // spec: "The init statement may be a short variable + // declaration, but the post statement must not." + if s, _ := s.Post.(*ast.AssignStmt); s != nil && s.Tok == token.DEFINE { + check.softErrorf(s.Pos(), "cannot declare in post statement") + // Don't call useLHS here because we want to use the lhs in + // this erroneous statement so that we don't get errors about + // these lhs variables being declared but not used. + check.use(s.Lhs...) // avoid follow-up errors + } + check.stmt(inner, s.Body) + + case *ast.RangeStmt: + inner |= breakOk | continueOk + check.openScope(s, "for") + defer check.closeScope() + + // check expression to iterate over + var x operand + check.expr(&x, s.X) + + // determine key/value types + var key, val Type + if x.mode != invalid { + switch typ := x.typ.Underlying().(type) { + case *Basic: + if isString(typ) { + key = Typ[Int] + val = universeRune // use 'rune' name + } + case *Array: + key = Typ[Int] + val = typ.elem + case *Slice: + key = Typ[Int] + val = typ.elem + case *Pointer: + if typ, _ := typ.base.Underlying().(*Array); typ != nil { + key = Typ[Int] + val = typ.elem + } + case *Map: + key = typ.key + val = typ.elem + case *Chan: + key = typ.elem + val = Typ[Invalid] + if typ.dir == SendOnly { + check.errorf(x.pos(), "cannot range over send-only channel %s", &x) + // ok to continue + } + if s.Value != nil { + check.errorf(s.Value.Pos(), "iteration over %s permits only one iteration variable", &x) + // ok to continue + } + } + } + + if key == nil { + check.errorf(x.pos(), "cannot range over %s", &x) + // ok to continue + } + + // check assignment to/declaration of iteration variables + // (irregular assignment, cannot easily map to existing assignment checks) + + // lhs expressions and initialization value (rhs) types + lhs := [2]ast.Expr{s.Key, s.Value} + rhs := [2]Type{key, val} // key, val may be nil + + if s.Tok == token.DEFINE { + // short variable declaration; variable scope starts after the range clause + // (the for loop opens a new scope, so variables on the lhs never redeclare + // previously declared variables) + var vars []*Var + for i, lhs := range lhs { + if lhs == nil { + continue + } + + // determine lhs variable + var obj *Var + if ident, _ := lhs.(*ast.Ident); ident != nil { + // declare new variable + name := ident.Name + obj = NewVar(ident.Pos(), check.pkg, name, nil) + check.recordDef(ident, obj) + // _ variables don't count as new variables + if name != "_" { + vars = append(vars, obj) + } + } else { + check.errorf(lhs.Pos(), "cannot declare %s", lhs) + obj = NewVar(lhs.Pos(), check.pkg, "_", nil) // dummy variable + } + + // initialize lhs variable + if typ := rhs[i]; typ != nil { + x.mode = value + x.expr = lhs // we don't have a better rhs expression to use here + x.typ = typ + check.initVar(obj, &x, "range clause") + } else { + obj.typ = Typ[Invalid] + obj.used = true // don't complain about unused variable + } + } + + // declare variables + if len(vars) > 0 { + scopePos := s.X.End() + for _, obj := range vars { + // spec: "The scope of a constant or variable identifier declared inside + // a function begins at the end of the ConstSpec or VarSpec (ShortVarDecl + // for short variable declarations) and ends at the end of the innermost + // containing block." + check.declare(check.scope, nil /* recordDef already called */, obj, scopePos) + } + } else { + check.error(s.TokPos, "no new variables on left side of :=") + } + } else { + // ordinary assignment + for i, lhs := range lhs { + if lhs == nil { + continue + } + if typ := rhs[i]; typ != nil { + x.mode = value + x.expr = lhs // we don't have a better rhs expression to use here + x.typ = typ + check.assignVar(lhs, &x) + } + } + } + + check.stmt(inner, s.Body) + + default: + check.error(s.Pos(), "invalid statement") + } +} diff --git a/third_party/forked/golang/go/types/type.go b/third_party/forked/golang/go/types/type.go new file mode 100644 index 00000000000..5db03f8f0ca --- /dev/null +++ b/third_party/forked/golang/go/types/type.go @@ -0,0 +1,464 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package types + +import "sort" + +// A Type represents a type of Go. +// All types implement the Type interface. +type Type interface { + // Underlying returns the underlying type of a type. + Underlying() Type + + // String returns a string representation of a type. + String() string +} + +// BasicKind describes the kind of basic type. +type BasicKind int + +const ( + Invalid BasicKind = iota // type is invalid + + // predeclared types + Bool + Int + Int8 + Int16 + Int32 + Int64 + Uint + Uint8 + Uint16 + Uint32 + Uint64 + Uintptr + Float32 + Float64 + Complex64 + Complex128 + String + UnsafePointer + + // types for untyped values + UntypedBool + UntypedInt + UntypedRune + UntypedFloat + UntypedComplex + UntypedString + UntypedNil + + // aliases + Byte = Uint8 + Rune = Int32 +) + +// BasicInfo is a set of flags describing properties of a basic type. +type BasicInfo int + +// Properties of basic types. +const ( + IsBoolean BasicInfo = 1 << iota + IsInteger + IsUnsigned + IsFloat + IsComplex + IsString + IsUntyped + + IsOrdered = IsInteger | IsFloat | IsString + IsNumeric = IsInteger | IsFloat | IsComplex + IsConstType = IsBoolean | IsNumeric | IsString +) + +// A Basic represents a basic type. +type Basic struct { + kind BasicKind + info BasicInfo + name string +} + +// Kind returns the kind of basic type b. +func (b *Basic) Kind() BasicKind { return b.kind } + +// Info returns information about properties of basic type b. +func (b *Basic) Info() BasicInfo { return b.info } + +// Name returns the name of basic type b. +func (b *Basic) Name() string { return b.name } + +// An Array represents an array type. +type Array struct { + len int64 + elem Type +} + +// NewArray returns a new array type for the given element type and length. +// A negative length indicates an unknown length. +func NewArray(elem Type, len int64) *Array { return &Array{len, elem} } + +// Len returns the length of array a. +// A negative result indicates an unknown length. +func (a *Array) Len() int64 { return a.len } + +// Elem returns element type of array a. +func (a *Array) Elem() Type { return a.elem } + +// A Slice represents a slice type. +type Slice struct { + elem Type +} + +// NewSlice returns a new slice type for the given element type. +func NewSlice(elem Type) *Slice { return &Slice{elem} } + +// Elem returns the element type of slice s. +func (s *Slice) Elem() Type { return s.elem } + +// A Struct represents a struct type. +type Struct struct { + fields []*Var + tags []string // field tags; nil if there are no tags +} + +// NewStruct returns a new struct with the given fields and corresponding field tags. +// If a field with index i has a tag, tags[i] must be that tag, but len(tags) may be +// only as long as required to hold the tag with the largest index i. Consequently, +// if no field has a tag, tags may be nil. +func NewStruct(fields []*Var, tags []string) *Struct { + var fset objset + for _, f := range fields { + if f.name != "_" && fset.insert(f) != nil { + panic("multiple fields with the same name") + } + } + if len(tags) > len(fields) { + panic("more tags than fields") + } + return &Struct{fields: fields, tags: tags} +} + +// NumFields returns the number of fields in the struct (including blank and anonymous fields). +func (s *Struct) NumFields() int { return len(s.fields) } + +// Field returns the i'th field for 0 <= i < NumFields(). +func (s *Struct) Field(i int) *Var { return s.fields[i] } + +// Tag returns the i'th field tag for 0 <= i < NumFields(). +func (s *Struct) Tag(i int) string { + if i < len(s.tags) { + return s.tags[i] + } + return "" +} + +// A Pointer represents a pointer type. +type Pointer struct { + base Type // element type +} + +// NewPointer returns a new pointer type for the given element (base) type. +func NewPointer(elem Type) *Pointer { return &Pointer{base: elem} } + +// Elem returns the element type for the given pointer p. +func (p *Pointer) Elem() Type { return p.base } + +// A Tuple represents an ordered list of variables; a nil *Tuple is a valid (empty) tuple. +// Tuples are used as components of signatures and to represent the type of multiple +// assignments; they are not first class types of Go. +type Tuple struct { + vars []*Var +} + +// NewTuple returns a new tuple for the given variables. +func NewTuple(x ...*Var) *Tuple { + if len(x) > 0 { + return &Tuple{x} + } + return nil +} + +// Len returns the number variables of tuple t. +func (t *Tuple) Len() int { + if t != nil { + return len(t.vars) + } + return 0 +} + +// At returns the i'th variable of tuple t. +func (t *Tuple) At(i int) *Var { return t.vars[i] } + +// A Signature represents a (non-builtin) function or method type. +// The receiver is ignored when comparing signatures for identity. +type Signature struct { + // We need to keep the scope in Signature (rather than passing it around + // and store it in the Func Object) because when type-checking a function + // literal we call the general type checker which returns a general Type. + // We then unpack the *Signature and use the scope for the literal body. + scope *Scope // function scope, present for package-local signatures + recv *Var // nil if not a method + params *Tuple // (incoming) parameters from left to right; or nil + results *Tuple // (outgoing) results from left to right; or nil + variadic bool // true if the last parameter's type is of the form ...T (or string, for append built-in only) +} + +// NewSignature returns a new function type for the given receiver, parameters, +// and results, either of which may be nil. If variadic is set, the function +// is variadic, it must have at least one parameter, and the last parameter +// must be of unnamed slice type. +func NewSignature(recv *Var, params, results *Tuple, variadic bool) *Signature { + if variadic { + n := params.Len() + if n == 0 { + panic("types.NewSignature: variadic function must have at least one parameter") + } + if _, ok := params.At(n - 1).typ.(*Slice); !ok { + panic("types.NewSignature: variadic parameter must be of unnamed slice type") + } + } + return &Signature{nil, recv, params, results, variadic} +} + +// Recv returns the receiver of signature s (if a method), or nil if a +// function. It is ignored when comparing signatures for identity. +// +// For an abstract method, Recv returns the enclosing interface either +// as a *Named or an *Interface. Due to embedding, an interface may +// contain methods whose receiver type is a different interface. +func (s *Signature) Recv() *Var { return s.recv } + +// Params returns the parameters of signature s, or nil. +func (s *Signature) Params() *Tuple { return s.params } + +// Results returns the results of signature s, or nil. +func (s *Signature) Results() *Tuple { return s.results } + +// Variadic reports whether the signature s is variadic. +func (s *Signature) Variadic() bool { return s.variadic } + +// An Interface represents an interface type. +type Interface struct { + methods []*Func // ordered list of explicitly declared methods + embeddeds []*Named // ordered list of explicitly embedded types + + allMethods []*Func // ordered list of methods declared with or embedded in this interface (TODO(gri): replace with mset) +} + +// emptyInterface represents the empty (completed) interface +var emptyInterface = Interface{allMethods: markComplete} + +// markComplete is used to mark an empty interface as completely +// set up by setting the allMethods field to a non-nil empty slice. +var markComplete = make([]*Func, 0) + +// NewInterface returns a new (incomplete) interface for the given methods and embedded types. +// To compute the method set of the interface, Complete must be called. +func NewInterface(methods []*Func, embeddeds []*Named) *Interface { + typ := new(Interface) + + if len(methods) == 0 && len(embeddeds) == 0 { + return typ + } + + var mset objset + for _, m := range methods { + if mset.insert(m) != nil { + panic("multiple methods with the same name") + } + // set receiver + // TODO(gri) Ideally, we should use a named type here instead of + // typ, for less verbose printing of interface method signatures. + m.typ.(*Signature).recv = NewVar(m.pos, m.pkg, "", typ) + } + sort.Sort(byUniqueMethodName(methods)) + + if embeddeds != nil { + sort.Sort(byUniqueTypeName(embeddeds)) + } + + typ.methods = methods + typ.embeddeds = embeddeds + return typ +} + +// NumExplicitMethods returns the number of explicitly declared methods of interface t. +func (t *Interface) NumExplicitMethods() int { return len(t.methods) } + +// ExplicitMethod returns the i'th explicitly declared method of interface t for 0 <= i < t.NumExplicitMethods(). +// The methods are ordered by their unique Id. +func (t *Interface) ExplicitMethod(i int) *Func { return t.methods[i] } + +// NumEmbeddeds returns the number of embedded types in interface t. +func (t *Interface) NumEmbeddeds() int { return len(t.embeddeds) } + +// Embedded returns the i'th embedded type of interface t for 0 <= i < t.NumEmbeddeds(). +// The types are ordered by the corresponding TypeName's unique Id. +func (t *Interface) Embedded(i int) *Named { return t.embeddeds[i] } + +// NumMethods returns the total number of methods of interface t. +func (t *Interface) NumMethods() int { return len(t.allMethods) } + +// Method returns the i'th method of interface t for 0 <= i < t.NumMethods(). +// The methods are ordered by their unique Id. +func (t *Interface) Method(i int) *Func { return t.allMethods[i] } + +// Empty returns true if t is the empty interface. +func (t *Interface) Empty() bool { return len(t.allMethods) == 0 } + +// Complete computes the interface's method set. It must be called by users of +// NewInterface after the interface's embedded types are fully defined and +// before using the interface type in any way other than to form other types. +// Complete returns the receiver. +func (t *Interface) Complete() *Interface { + if t.allMethods != nil { + return t + } + + var allMethods []*Func + if t.embeddeds == nil { + if t.methods == nil { + allMethods = make([]*Func, 0, 1) + } else { + allMethods = t.methods + } + } else { + allMethods = append(allMethods, t.methods...) + for _, et := range t.embeddeds { + it := et.Underlying().(*Interface) + it.Complete() + for _, tm := range it.allMethods { + // Make a copy of the method and adjust its receiver type. + newm := *tm + newmtyp := *tm.typ.(*Signature) + newm.typ = &newmtyp + newmtyp.recv = NewVar(newm.pos, newm.pkg, "", t) + allMethods = append(allMethods, &newm) + } + } + sort.Sort(byUniqueMethodName(allMethods)) + } + t.allMethods = allMethods + + return t +} + +// A Map represents a map type. +type Map struct { + key, elem Type +} + +// NewMap returns a new map for the given key and element types. +func NewMap(key, elem Type) *Map { + return &Map{key, elem} +} + +// Key returns the key type of map m. +func (m *Map) Key() Type { return m.key } + +// Elem returns the element type of map m. +func (m *Map) Elem() Type { return m.elem } + +// A Chan represents a channel type. +type Chan struct { + dir ChanDir + elem Type +} + +// A ChanDir value indicates a channel direction. +type ChanDir int + +// The direction of a channel is indicated by one of these constants. +const ( + SendRecv ChanDir = iota + SendOnly + RecvOnly +) + +// NewChan returns a new channel type for the given direction and element type. +func NewChan(dir ChanDir, elem Type) *Chan { + return &Chan{dir, elem} +} + +// Dir returns the direction of channel c. +func (c *Chan) Dir() ChanDir { return c.dir } + +// Elem returns the element type of channel c. +func (c *Chan) Elem() Type { return c.elem } + +// A Named represents a named type. +type Named struct { + obj *TypeName // corresponding declared object + underlying Type // possibly a *Named during setup; never a *Named once set up completely + methods []*Func // methods declared for this type (not the method set of this type) +} + +// NewNamed returns a new named type for the given type name, underlying type, and associated methods. +// If the given type name obj doesn't have a type yet, its type is set to the returned named type. +// The underlying type must not be a *Named. +func NewNamed(obj *TypeName, underlying Type, methods []*Func) *Named { + if _, ok := underlying.(*Named); ok { + panic("types.NewNamed: underlying type must not be *Named") + } + typ := &Named{obj: obj, underlying: underlying, methods: methods} + if obj.typ == nil { + obj.typ = typ + } + return typ +} + +// Obj returns the type name for the named type t. +func (t *Named) Obj() *TypeName { return t.obj } + +// NumMethods returns the number of explicit methods whose receiver is named type t. +func (t *Named) NumMethods() int { return len(t.methods) } + +// Method returns the i'th method of named type t for 0 <= i < t.NumMethods(). +func (t *Named) Method(i int) *Func { return t.methods[i] } + +// SetUnderlying sets the underlying type and marks t as complete. +func (t *Named) SetUnderlying(underlying Type) { + if underlying == nil { + panic("types.Named.SetUnderlying: underlying type must not be nil") + } + if _, ok := underlying.(*Named); ok { + panic("types.Named.SetUnderlying: underlying type must not be *Named") + } + t.underlying = underlying +} + +// AddMethod adds method m unless it is already in the method list. +func (t *Named) AddMethod(m *Func) { + if i, _ := lookupMethod(t.methods, m.pkg, m.name); i < 0 { + t.methods = append(t.methods, m) + } +} + +// Implementations for Type methods. + +func (t *Basic) Underlying() Type { return t } +func (t *Array) Underlying() Type { return t } +func (t *Slice) Underlying() Type { return t } +func (t *Struct) Underlying() Type { return t } +func (t *Pointer) Underlying() Type { return t } +func (t *Tuple) Underlying() Type { return t } +func (t *Signature) Underlying() Type { return t } +func (t *Interface) Underlying() Type { return t } +func (t *Map) Underlying() Type { return t } +func (t *Chan) Underlying() Type { return t } +func (t *Named) Underlying() Type { return t.underlying } + +func (t *Basic) String() string { return TypeString(t, nil) } +func (t *Array) String() string { return TypeString(t, nil) } +func (t *Slice) String() string { return TypeString(t, nil) } +func (t *Struct) String() string { return TypeString(t, nil) } +func (t *Pointer) String() string { return TypeString(t, nil) } +func (t *Tuple) String() string { return TypeString(t, nil) } +func (t *Signature) String() string { return TypeString(t, nil) } +func (t *Interface) String() string { return TypeString(t, nil) } +func (t *Map) String() string { return TypeString(t, nil) } +func (t *Chan) String() string { return TypeString(t, nil) } +func (t *Named) String() string { return TypeString(t, nil) } diff --git a/third_party/forked/golang/go/types/typestring.go b/third_party/forked/golang/go/types/typestring.go new file mode 100644 index 00000000000..a9c0bfde1f9 --- /dev/null +++ b/third_party/forked/golang/go/types/typestring.go @@ -0,0 +1,307 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements printing of types. + +package types + +import ( + "bytes" + "fmt" +) + +// A Qualifier controls how named package-level objects are printed in +// calls to TypeString, ObjectString, and SelectionString. +// +// These three formatting routines call the Qualifier for each +// package-level object O, and if the Qualifier returns a non-empty +// string p, the object is printed in the form p.O. +// If it returns an empty string, only the object name O is printed. +// +// Using a nil Qualifier is equivalent to using (*Package).Path: the +// object is qualified by the import path, e.g., "encoding/json.Marshal". +// +type Qualifier func(*Package) string + +// RelativeTo(pkg) returns a Qualifier that fully qualifies members of +// all packages other than pkg. +func RelativeTo(pkg *Package) Qualifier { + if pkg == nil { + return nil + } + return func(other *Package) string { + if pkg == other { + return "" // same package; unqualified + } + return other.Path() + } +} + +// If gcCompatibilityMode is set, printing of types is modified +// to match the representation of some types in the gc compiler: +// +// - byte and rune lose their alias name and simply stand for +// uint8 and int32 respectively +// - embedded interfaces get flattened (the embedding info is lost, +// and certain recursive interface types cannot be printed anymore) +// +// This makes it easier to compare packages computed with the type- +// checker vs packages imported from gc export data. +// +// Caution: This flag affects all uses of WriteType, globally. +// It is only provided for testing in conjunction with +// gc-generated data. +// +// This flag is exported in the x/tools/go/types package. We don't +// need it at the moment in the std repo and so we don't export it +// anymore. We should eventually try to remove it altogether. +// TODO(gri) remove this +var gcCompatibilityMode bool + +// TypeString returns the string representation of typ. +// The Qualifier controls the printing of +// package-level objects, and may be nil. +func TypeString(typ Type, qf Qualifier) string { + var buf bytes.Buffer + WriteType(&buf, typ, qf) + return buf.String() +} + +// WriteType writes the string representation of typ to buf. +// The Qualifier controls the printing of +// package-level objects, and may be nil. +func WriteType(buf *bytes.Buffer, typ Type, qf Qualifier) { + writeType(buf, typ, qf, make([]Type, 0, 8)) +} + +func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) { + // Theoretically, this is a quadratic lookup algorithm, but in + // practice deeply nested composite types with unnamed component + // types are uncommon. This code is likely more efficient than + // using a map. + for _, t := range visited { + if t == typ { + fmt.Fprintf(buf, "○%T", typ) // cycle to typ + return + } + } + visited = append(visited, typ) + + switch t := typ.(type) { + case nil: + buf.WriteString("") + + case *Basic: + if t.kind == UnsafePointer { + buf.WriteString("unsafe.") + } + if gcCompatibilityMode { + // forget the alias names + switch t.kind { + case Byte: + t = Typ[Uint8] + case Rune: + t = Typ[Int32] + } + } + buf.WriteString(t.name) + + case *Array: + fmt.Fprintf(buf, "[%d]", t.len) + writeType(buf, t.elem, qf, visited) + + case *Slice: + buf.WriteString("[]") + writeType(buf, t.elem, qf, visited) + + case *Struct: + buf.WriteString("struct{") + for i, f := range t.fields { + if i > 0 { + buf.WriteString("; ") + } + if !f.anonymous { + buf.WriteString(f.name) + buf.WriteByte(' ') + } + writeType(buf, f.typ, qf, visited) + if tag := t.Tag(i); tag != "" { + fmt.Fprintf(buf, " %q", tag) + } + } + buf.WriteByte('}') + + case *Pointer: + buf.WriteByte('*') + writeType(buf, t.base, qf, visited) + + case *Tuple: + writeTuple(buf, t, false, qf, visited) + + case *Signature: + buf.WriteString("func") + writeSignature(buf, t, qf, visited) + + case *Interface: + // We write the source-level methods and embedded types rather + // than the actual method set since resolved method signatures + // may have non-printable cycles if parameters have anonymous + // interface types that (directly or indirectly) embed the + // current interface. For instance, consider the result type + // of m: + // + // type T interface{ + // m() interface{ T } + // } + // + buf.WriteString("interface{") + empty := true + if gcCompatibilityMode { + // print flattened interface + // (useful to compare against gc-generated interfaces) + for i, m := range t.allMethods { + if i > 0 { + buf.WriteString("; ") + } + buf.WriteString(m.name) + writeSignature(buf, m.typ.(*Signature), qf, visited) + empty = false + } + } else { + // print explicit interface methods and embedded types + for i, m := range t.methods { + if i > 0 { + buf.WriteString("; ") + } + buf.WriteString(m.name) + writeSignature(buf, m.typ.(*Signature), qf, visited) + empty = false + } + for i, typ := range t.embeddeds { + if i > 0 || len(t.methods) > 0 { + buf.WriteString("; ") + } + writeType(buf, typ, qf, visited) + empty = false + } + } + if t.allMethods == nil || len(t.methods) > len(t.allMethods) { + if !empty { + buf.WriteByte(' ') + } + buf.WriteString("/* incomplete */") + } + buf.WriteByte('}') + + case *Map: + buf.WriteString("map[") + writeType(buf, t.key, qf, visited) + buf.WriteByte(']') + writeType(buf, t.elem, qf, visited) + + case *Chan: + var s string + var parens bool + switch t.dir { + case SendRecv: + s = "chan " + // chan (<-chan T) requires parentheses + if c, _ := t.elem.(*Chan); c != nil && c.dir == RecvOnly { + parens = true + } + case SendOnly: + s = "chan<- " + case RecvOnly: + s = "<-chan " + default: + panic("unreachable") + } + buf.WriteString(s) + if parens { + buf.WriteByte('(') + } + writeType(buf, t.elem, qf, visited) + if parens { + buf.WriteByte(')') + } + + case *Named: + s := "" + if obj := t.obj; obj != nil { + if obj.pkg != nil { + writePackage(buf, obj.pkg, qf) + } + // TODO(gri): function-local named types should be displayed + // differently from named types at package level to avoid + // ambiguity. + s = obj.name + } + buf.WriteString(s) + + default: + // For externally defined implementations of Type. + buf.WriteString(t.String()) + } +} + +func writeTuple(buf *bytes.Buffer, tup *Tuple, variadic bool, qf Qualifier, visited []Type) { + buf.WriteByte('(') + if tup != nil { + for i, v := range tup.vars { + if i > 0 { + buf.WriteString(", ") + } + if v.name != "" { + buf.WriteString(v.name) + buf.WriteByte(' ') + } + typ := v.typ + if variadic && i == len(tup.vars)-1 { + if s, ok := typ.(*Slice); ok { + buf.WriteString("...") + typ = s.elem + } else { + // special case: + // append(s, "foo"...) leads to signature func([]byte, string...) + if t, ok := typ.Underlying().(*Basic); !ok || t.kind != String { + panic("internal error: string type expected") + } + writeType(buf, typ, qf, visited) + buf.WriteString("...") + continue + } + } + writeType(buf, typ, qf, visited) + } + } + buf.WriteByte(')') +} + +// WriteSignature writes the representation of the signature sig to buf, +// without a leading "func" keyword. +// The Qualifier controls the printing of +// package-level objects, and may be nil. +func WriteSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier) { + writeSignature(buf, sig, qf, make([]Type, 0, 8)) +} + +func writeSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier, visited []Type) { + writeTuple(buf, sig.params, sig.variadic, qf, visited) + + n := sig.results.Len() + if n == 0 { + // no result + return + } + + buf.WriteByte(' ') + if n == 1 && sig.results.vars[0].name == "" { + // single unnamed result + writeType(buf, sig.results.vars[0].typ, qf, visited) + return + } + + // multiple or named result(s) + writeTuple(buf, sig.results, false, qf, visited) +} diff --git a/third_party/forked/golang/go/types/typexpr.go b/third_party/forked/golang/go/types/typexpr.go new file mode 100644 index 00000000000..e4e42e7993b --- /dev/null +++ b/third_party/forked/golang/go/types/typexpr.go @@ -0,0 +1,722 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements type-checking of identifiers and type expressions. + +package types + +import ( + "go/ast" + "go/constant" + "go/token" + "sort" + "strconv" +) + +// ident type-checks identifier e and initializes x with the value or type of e. +// If an error occurred, x.mode is set to invalid. +// For the meaning of def and path, see check.typ, below. +// +func (check *Checker) ident(x *operand, e *ast.Ident, def *Named, path []*TypeName) { + x.mode = invalid + x.expr = e + + scope, obj := check.scope.LookupParent(e.Name, check.pos) + if obj == nil { + if e.Name == "_" { + check.errorf(e.Pos(), "cannot use _ as value or type") + } else { + check.errorf(e.Pos(), "undeclared name: %s", e.Name) + } + return + } + check.recordUse(e, obj) + + check.objDecl(obj, def, path) + typ := obj.Type() + assert(typ != nil) + + // The object may be dot-imported: If so, remove its package from + // the map of unused dot imports for the respective file scope. + // (This code is only needed for dot-imports. Without them, + // we only have to mark variables, see *Var case below). + if pkg := obj.Pkg(); pkg != check.pkg && pkg != nil { + delete(check.unusedDotImports[scope], pkg) + } + + switch obj := obj.(type) { + case *PkgName: + check.errorf(e.Pos(), "use of package %s not in selector", obj.name) + return + + case *Const: + check.addDeclDep(obj) + if typ == Typ[Invalid] { + return + } + if obj == universeIota { + if check.iota == nil { + check.errorf(e.Pos(), "cannot use iota outside constant declaration") + return + } + x.val = check.iota + } else { + x.val = obj.val + } + assert(x.val != nil) + x.mode = constant_ + + case *TypeName: + x.mode = typexpr + // check for cycle + // (it's ok to iterate forward because each named type appears at most once in path) + for i, prev := range path { + if prev == obj { + check.errorf(obj.pos, "illegal cycle in declaration of %s", obj.name) + // print cycle + for _, obj := range path[i:] { + check.errorf(obj.Pos(), "\t%s refers to", obj.Name()) // secondary error, \t indented + } + check.errorf(obj.Pos(), "\t%s", obj.Name()) + // maintain x.mode == typexpr despite error + typ = Typ[Invalid] + break + } + } + + case *Var: + // It's ok to mark non-local variables, but ignore variables + // from other packages to avoid potential race conditions with + // dot-imported variables. + if obj.pkg == check.pkg { + obj.used = true + } + check.addDeclDep(obj) + if typ == Typ[Invalid] { + return + } + x.mode = variable + + case *Func: + check.addDeclDep(obj) + x.mode = value + + case *Builtin: + x.id = obj.id + x.mode = builtin + + case *Nil: + x.mode = value + + default: + unreachable() + } + + x.typ = typ +} + +// typExpr type-checks the type expression e and returns its type, or Typ[Invalid]. +// If def != nil, e is the type specification for the named type def, declared +// in a type declaration, and def.underlying will be set to the type of e before +// any components of e are type-checked. Path contains the path of named types +// referring to this type. +// +func (check *Checker) typExpr(e ast.Expr, def *Named, path []*TypeName) (T Type) { + if trace { + check.trace(e.Pos(), "%s", e) + check.indent++ + defer func() { + check.indent-- + check.trace(e.Pos(), "=> %s", T) + }() + } + + T = check.typExprInternal(e, def, path) + assert(isTyped(T)) + check.recordTypeAndValue(e, typexpr, T, nil) + + return +} + +func (check *Checker) typ(e ast.Expr) Type { + return check.typExpr(e, nil, nil) +} + +// funcType type-checks a function or method type. +func (check *Checker) funcType(sig *Signature, recvPar *ast.FieldList, ftyp *ast.FuncType) { + scope := NewScope(check.scope, token.NoPos, token.NoPos, "function") + scope.isFunc = true + check.recordScope(ftyp, scope) + + recvList, _ := check.collectParams(scope, recvPar, false) + params, variadic := check.collectParams(scope, ftyp.Params, true) + results, _ := check.collectParams(scope, ftyp.Results, false) + + if recvPar != nil { + // recv parameter list present (may be empty) + // spec: "The receiver is specified via an extra parameter section preceding the + // method name. That parameter section must declare a single parameter, the receiver." + var recv *Var + switch len(recvList) { + case 0: + check.error(recvPar.Pos(), "method is missing receiver") + recv = NewParam(0, nil, "", Typ[Invalid]) // ignore recv below + default: + // more than one receiver + check.error(recvList[len(recvList)-1].Pos(), "method must have exactly one receiver") + fallthrough // continue with first receiver + case 1: + recv = recvList[0] + } + // spec: "The receiver type must be of the form T or *T where T is a type name." + // (ignore invalid types - error was reported before) + if t, _ := deref(recv.typ); t != Typ[Invalid] { + var err string + if T, _ := t.(*Named); T != nil { + // spec: "The type denoted by T is called the receiver base type; it must not + // be a pointer or interface type and it must be declared in the same package + // as the method." + if T.obj.pkg != check.pkg { + err = "type not defined in this package" + } else { + // TODO(gri) This is not correct if the underlying type is unknown yet. + switch u := T.underlying.(type) { + case *Basic: + // unsafe.Pointer is treated like a regular pointer + if u.kind == UnsafePointer { + err = "unsafe.Pointer" + } + case *Pointer, *Interface: + err = "pointer or interface type" + } + } + } else { + err = "basic or unnamed type" + } + if err != "" { + check.errorf(recv.pos, "invalid receiver %s (%s)", recv.typ, err) + // ok to continue + } + } + sig.recv = recv + } + + sig.scope = scope + sig.params = NewTuple(params...) + sig.results = NewTuple(results...) + sig.variadic = variadic +} + +// typExprInternal drives type checking of types. +// Must only be called by typExpr. +// +func (check *Checker) typExprInternal(e ast.Expr, def *Named, path []*TypeName) Type { + switch e := e.(type) { + case *ast.BadExpr: + // ignore - error reported before + + case *ast.Ident: + var x operand + check.ident(&x, e, def, path) + + switch x.mode { + case typexpr: + typ := x.typ + def.setUnderlying(typ) + return typ + case invalid: + // ignore - error reported before + case novalue: + check.errorf(x.pos(), "%s used as type", &x) + default: + check.errorf(x.pos(), "%s is not a type", &x) + } + + case *ast.SelectorExpr: + var x operand + check.selector(&x, e) + + switch x.mode { + case typexpr: + typ := x.typ + def.setUnderlying(typ) + return typ + case invalid: + // ignore - error reported before + case novalue: + check.errorf(x.pos(), "%s used as type", &x) + default: + check.errorf(x.pos(), "%s is not a type", &x) + } + + case *ast.ParenExpr: + return check.typExpr(e.X, def, path) + + case *ast.ArrayType: + if e.Len != nil { + typ := new(Array) + def.setUnderlying(typ) + typ.len = check.arrayLength(e.Len) + typ.elem = check.typExpr(e.Elt, nil, path) + return typ + + } else { + typ := new(Slice) + def.setUnderlying(typ) + typ.elem = check.typ(e.Elt) + return typ + } + + case *ast.StructType: + typ := new(Struct) + def.setUnderlying(typ) + check.structType(typ, e, path) + return typ + + case *ast.StarExpr: + typ := new(Pointer) + def.setUnderlying(typ) + typ.base = check.typ(e.X) + return typ + + case *ast.FuncType: + typ := new(Signature) + def.setUnderlying(typ) + check.funcType(typ, nil, e) + return typ + + case *ast.InterfaceType: + typ := new(Interface) + def.setUnderlying(typ) + check.interfaceType(typ, e, def, path) + return typ + + case *ast.MapType: + typ := new(Map) + def.setUnderlying(typ) + + typ.key = check.typ(e.Key) + typ.elem = check.typ(e.Value) + + // spec: "The comparison operators == and != must be fully defined + // for operands of the key type; thus the key type must not be a + // function, map, or slice." + // + // Delay this check because it requires fully setup types; + // it is safe to continue in any case (was issue 6667). + check.delay(func() { + if !Comparable(typ.key) { + check.errorf(e.Key.Pos(), "invalid map key type %s", typ.key) + } + }) + + return typ + + case *ast.ChanType: + typ := new(Chan) + def.setUnderlying(typ) + + dir := SendRecv + switch e.Dir { + case ast.SEND | ast.RECV: + // nothing to do + case ast.SEND: + dir = SendOnly + case ast.RECV: + dir = RecvOnly + default: + check.invalidAST(e.Pos(), "unknown channel direction %d", e.Dir) + // ok to continue + } + + typ.dir = dir + typ.elem = check.typ(e.Value) + return typ + + default: + check.errorf(e.Pos(), "%s is not a type", e) + } + + typ := Typ[Invalid] + def.setUnderlying(typ) + return typ +} + +// typeOrNil type-checks the type expression (or nil value) e +// and returns the typ of e, or nil. +// If e is neither a type nor nil, typOrNil returns Typ[Invalid]. +// +func (check *Checker) typOrNil(e ast.Expr) Type { + var x operand + check.rawExpr(&x, e, nil) + switch x.mode { + case invalid: + // ignore - error reported before + case novalue: + check.errorf(x.pos(), "%s used as type", &x) + case typexpr: + return x.typ + case value: + if x.isNil() { + return nil + } + fallthrough + default: + check.errorf(x.pos(), "%s is not a type", &x) + } + return Typ[Invalid] +} + +// arrayLength type-checks the array length expression e +// and returns the constant length >= 0, or a value < 0 +// to indicate an error (and thus an unknown length). +func (check *Checker) arrayLength(e ast.Expr) int64 { + var x operand + check.expr(&x, e) + if x.mode != constant_ { + if x.mode != invalid { + check.errorf(x.pos(), "array length %s must be constant", &x) + } + return -1 + } + if isUntyped(x.typ) || isInteger(x.typ) { + if val := constant.ToInt(x.val); val.Kind() == constant.Int { + if representableConst(val, check.conf, Typ[Int], nil) { + if n, ok := constant.Int64Val(val); ok && n >= 0 { + return n + } + check.errorf(x.pos(), "invalid array length %s", &x) + return -1 + } + } + } + check.errorf(x.pos(), "array length %s must be integer", &x) + return -1 +} + +func (check *Checker) collectParams(scope *Scope, list *ast.FieldList, variadicOk bool) (params []*Var, variadic bool) { + if list == nil { + return + } + + var named, anonymous bool + for i, field := range list.List { + ftype := field.Type + if t, _ := ftype.(*ast.Ellipsis); t != nil { + ftype = t.Elt + if variadicOk && i == len(list.List)-1 { + variadic = true + } else { + check.invalidAST(field.Pos(), "... not permitted") + // ignore ... and continue + } + } + typ := check.typ(ftype) + // The parser ensures that f.Tag is nil and we don't + // care if a constructed AST contains a non-nil tag. + if len(field.Names) > 0 { + // named parameter + for _, name := range field.Names { + if name.Name == "" { + check.invalidAST(name.Pos(), "anonymous parameter") + // ok to continue + } + par := NewParam(name.Pos(), check.pkg, name.Name, typ) + check.declare(scope, name, par, scope.pos) + params = append(params, par) + } + named = true + } else { + // anonymous parameter + par := NewParam(ftype.Pos(), check.pkg, "", typ) + check.recordImplicit(field, par) + params = append(params, par) + anonymous = true + } + } + + if named && anonymous { + check.invalidAST(list.Pos(), "list contains both named and anonymous parameters") + // ok to continue + } + + // For a variadic function, change the last parameter's type from T to []T. + if variadic && len(params) > 0 { + last := params[len(params)-1] + last.typ = &Slice{elem: last.typ} + } + + return +} + +func (check *Checker) declareInSet(oset *objset, pos token.Pos, obj Object) bool { + if alt := oset.insert(obj); alt != nil { + check.errorf(pos, "%s redeclared", obj.Name()) + check.reportAltDecl(alt) + return false + } + return true +} + +func (check *Checker) interfaceType(iface *Interface, ityp *ast.InterfaceType, def *Named, path []*TypeName) { + // empty interface: common case + if ityp.Methods == nil { + return + } + + // The parser ensures that field tags are nil and we don't + // care if a constructed AST contains non-nil tags. + + // use named receiver type if available (for better error messages) + var recvTyp Type = iface + if def != nil { + recvTyp = def + } + + // Phase 1: Collect explicitly declared methods, the corresponding + // signature (AST) expressions, and the list of embedded + // type (AST) expressions. Do not resolve signatures or + // embedded types yet to avoid cycles referring to this + // interface. + + var ( + mset objset + signatures []ast.Expr // list of corresponding method signatures + embedded []ast.Expr // list of embedded types + ) + for _, f := range ityp.Methods.List { + if len(f.Names) > 0 { + // The parser ensures that there's only one method + // and we don't care if a constructed AST has more. + name := f.Names[0] + pos := name.Pos() + // spec: "As with all method sets, in an interface type, + // each method must have a unique non-blank name." + if name.Name == "_" { + check.errorf(pos, "invalid method name _") + continue + } + // Don't type-check signature yet - use an + // empty signature now and update it later. + // Since we know the receiver, set it up now + // (required to avoid crash in ptrRecv; see + // e.g. test case for issue 6638). + // TODO(gri) Consider marking methods signatures + // as incomplete, for better error messages. See + // also the T4 and T5 tests in testdata/cycles2.src. + sig := new(Signature) + sig.recv = NewVar(pos, check.pkg, "", recvTyp) + m := NewFunc(pos, check.pkg, name.Name, sig) + if check.declareInSet(&mset, pos, m) { + iface.methods = append(iface.methods, m) + iface.allMethods = append(iface.allMethods, m) + signatures = append(signatures, f.Type) + check.recordDef(name, m) + } + } else { + // embedded type + embedded = append(embedded, f.Type) + } + } + + // Phase 2: Resolve embedded interfaces. Because an interface must not + // embed itself (directly or indirectly), each embedded interface + // can be fully resolved without depending on any method of this + // interface (if there is a cycle or another error, the embedded + // type resolves to an invalid type and is ignored). + // In particular, the list of methods for each embedded interface + // must be complete (it cannot depend on this interface), and so + // those methods can be added to the list of all methods of this + // interface. + + for _, e := range embedded { + pos := e.Pos() + typ := check.typExpr(e, nil, path) + // Determine underlying embedded (possibly incomplete) type + // by following its forward chain. + named, _ := typ.(*Named) + under := underlying(named) + embed, _ := under.(*Interface) + if embed == nil { + if typ != Typ[Invalid] { + check.errorf(pos, "%s is not an interface", typ) + } + continue + } + iface.embeddeds = append(iface.embeddeds, named) + // collect embedded methods + if embed.allMethods == nil { + check.errorf(pos, "internal error: incomplete embedded interface %s (issue #18395)", named) + } + for _, m := range embed.allMethods { + if check.declareInSet(&mset, pos, m) { + iface.allMethods = append(iface.allMethods, m) + } + } + } + + // Phase 3: At this point all methods have been collected for this interface. + // It is now safe to type-check the signatures of all explicitly + // declared methods, even if they refer to this interface via a cycle + // and embed the methods of this interface in a parameter of interface + // type. + + for i, m := range iface.methods { + expr := signatures[i] + typ := check.typ(expr) + sig, _ := typ.(*Signature) + if sig == nil { + if typ != Typ[Invalid] { + check.invalidAST(expr.Pos(), "%s is not a method signature", typ) + } + continue // keep method with empty method signature + } + // update signature, but keep recv that was set up before + old := m.typ.(*Signature) + sig.recv = old.recv + *old = *sig // update signature (don't replace it!) + } + + // TODO(gri) The list of explicit methods is only sorted for now to + // produce the same Interface as NewInterface. We may be able to + // claim source order in the future. Revisit. + sort.Sort(byUniqueMethodName(iface.methods)) + + // TODO(gri) The list of embedded types is only sorted for now to + // produce the same Interface as NewInterface. We may be able to + // claim source order in the future. Revisit. + sort.Sort(byUniqueTypeName(iface.embeddeds)) + + if iface.allMethods == nil { + iface.allMethods = make([]*Func, 0) // mark interface as complete + } else { + sort.Sort(byUniqueMethodName(iface.allMethods)) + } +} + +// byUniqueTypeName named type lists can be sorted by their unique type names. +type byUniqueTypeName []*Named + +func (a byUniqueTypeName) Len() int { return len(a) } +func (a byUniqueTypeName) Less(i, j int) bool { return a[i].obj.Id() < a[j].obj.Id() } +func (a byUniqueTypeName) Swap(i, j int) { a[i], a[j] = a[j], a[i] } + +// byUniqueMethodName method lists can be sorted by their unique method names. +type byUniqueMethodName []*Func + +func (a byUniqueMethodName) Len() int { return len(a) } +func (a byUniqueMethodName) Less(i, j int) bool { return a[i].Id() < a[j].Id() } +func (a byUniqueMethodName) Swap(i, j int) { a[i], a[j] = a[j], a[i] } + +func (check *Checker) tag(t *ast.BasicLit) string { + if t != nil { + if t.Kind == token.STRING { + if val, err := strconv.Unquote(t.Value); err == nil { + return val + } + } + check.invalidAST(t.Pos(), "incorrect tag syntax: %q", t.Value) + } + return "" +} + +func (check *Checker) structType(styp *Struct, e *ast.StructType, path []*TypeName) { + list := e.Fields + if list == nil { + return + } + + // struct fields and tags + var fields []*Var + var tags []string + + // for double-declaration checks + var fset objset + + // current field typ and tag + var typ Type + var tag string + add := func(ident *ast.Ident, anonymous bool, pos token.Pos) { + if tag != "" && tags == nil { + tags = make([]string, len(fields)) + } + if tags != nil { + tags = append(tags, tag) + } + + name := ident.Name + fld := NewField(pos, check.pkg, name, typ, anonymous) + // spec: "Within a struct, non-blank field names must be unique." + if name == "_" || check.declareInSet(&fset, pos, fld) { + fields = append(fields, fld) + check.recordDef(ident, fld) + } + } + + for _, f := range list.List { + typ = check.typExpr(f.Type, nil, path) + tag = check.tag(f.Tag) + if len(f.Names) > 0 { + // named fields + for _, name := range f.Names { + add(name, false, name.Pos()) + } + } else { + // anonymous field + // spec: "An embedded type must be specified as a type name T or as a pointer + // to a non-interface type name *T, and T itself may not be a pointer type." + pos := f.Type.Pos() + name := anonymousFieldIdent(f.Type) + if name == nil { + check.invalidAST(pos, "anonymous field type %s has no name", f.Type) + continue + } + t, isPtr := deref(typ) + // Because we have a name, typ must be of the form T or *T, where T is the name + // of a (named or alias) type, and t (= deref(typ)) must be the type of T. + switch t := t.Underlying().(type) { + case *Basic: + if t == Typ[Invalid] { + // error was reported before + continue + } + + // unsafe.Pointer is treated like a regular pointer + if t.kind == UnsafePointer { + check.errorf(pos, "anonymous field type cannot be unsafe.Pointer") + continue + } + + case *Pointer: + check.errorf(pos, "anonymous field type cannot be a pointer") + continue + + case *Interface: + if isPtr { + check.errorf(pos, "anonymous field type cannot be a pointer to an interface") + continue + } + } + add(name, true, pos) + } + } + + styp.fields = fields + styp.tags = tags +} + +func anonymousFieldIdent(e ast.Expr) *ast.Ident { + switch e := e.(type) { + case *ast.Ident: + return e + case *ast.StarExpr: + // *T is valid, but **T is not + if _, ok := e.X.(*ast.StarExpr); !ok { + return anonymousFieldIdent(e.X) + } + case *ast.SelectorExpr: + return e.Sel + } + return nil // invalid anonymous field +} diff --git a/third_party/forked/golang/go/types/universe.go b/third_party/forked/golang/go/types/universe.go new file mode 100644 index 00000000000..07d7078ae25 --- /dev/null +++ b/third_party/forked/golang/go/types/universe.go @@ -0,0 +1,229 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file sets up the universe scope and the unsafe package. + +package types + +import ( + "go/constant" + "go/token" + "strings" +) + +var ( + Universe *Scope + Unsafe *Package + universeIota *Const + universeByte *Basic // uint8 alias, but has name "byte" + universeRune *Basic // int32 alias, but has name "rune" +) + +// Typ contains the predeclared *Basic types indexed by their +// corresponding BasicKind. +// +// The *Basic type for Typ[Byte] will have the name "uint8". +// Use Universe.Lookup("byte").Type() to obtain the specific +// alias basic type named "byte" (and analogous for "rune"). +var Typ = []*Basic{ + Invalid: {Invalid, 0, "invalid type"}, + + Bool: {Bool, IsBoolean, "bool"}, + Int: {Int, IsInteger, "int"}, + Int8: {Int8, IsInteger, "int8"}, + Int16: {Int16, IsInteger, "int16"}, + Int32: {Int32, IsInteger, "int32"}, + Int64: {Int64, IsInteger, "int64"}, + Uint: {Uint, IsInteger | IsUnsigned, "uint"}, + Uint8: {Uint8, IsInteger | IsUnsigned, "uint8"}, + Uint16: {Uint16, IsInteger | IsUnsigned, "uint16"}, + Uint32: {Uint32, IsInteger | IsUnsigned, "uint32"}, + Uint64: {Uint64, IsInteger | IsUnsigned, "uint64"}, + Uintptr: {Uintptr, IsInteger | IsUnsigned, "uintptr"}, + Float32: {Float32, IsFloat, "float32"}, + Float64: {Float64, IsFloat, "float64"}, + Complex64: {Complex64, IsComplex, "complex64"}, + Complex128: {Complex128, IsComplex, "complex128"}, + String: {String, IsString, "string"}, + UnsafePointer: {UnsafePointer, 0, "Pointer"}, + + UntypedBool: {UntypedBool, IsBoolean | IsUntyped, "untyped bool"}, + UntypedInt: {UntypedInt, IsInteger | IsUntyped, "untyped int"}, + UntypedRune: {UntypedRune, IsInteger | IsUntyped, "untyped rune"}, + UntypedFloat: {UntypedFloat, IsFloat | IsUntyped, "untyped float"}, + UntypedComplex: {UntypedComplex, IsComplex | IsUntyped, "untyped complex"}, + UntypedString: {UntypedString, IsString | IsUntyped, "untyped string"}, + UntypedNil: {UntypedNil, IsUntyped, "untyped nil"}, +} + +var aliases = [...]*Basic{ + {Byte, IsInteger | IsUnsigned, "byte"}, + {Rune, IsInteger, "rune"}, +} + +func defPredeclaredTypes() { + for _, t := range Typ { + def(NewTypeName(token.NoPos, nil, t.name, t)) + } + for _, t := range aliases { + def(NewTypeName(token.NoPos, nil, t.name, t)) + } + + // Error has a nil package in its qualified name since it is in no package + res := NewVar(token.NoPos, nil, "", Typ[String]) + sig := &Signature{results: NewTuple(res)} + err := NewFunc(token.NoPos, nil, "Error", sig) + typ := &Named{underlying: NewInterface([]*Func{err}, nil).Complete()} + sig.recv = NewVar(token.NoPos, nil, "", typ) + def(NewTypeName(token.NoPos, nil, "error", typ)) +} + +var predeclaredConsts = [...]struct { + name string + kind BasicKind + val constant.Value +}{ + {"true", UntypedBool, constant.MakeBool(true)}, + {"false", UntypedBool, constant.MakeBool(false)}, + {"iota", UntypedInt, constant.MakeInt64(0)}, +} + +func defPredeclaredConsts() { + for _, c := range predeclaredConsts { + def(NewConst(token.NoPos, nil, c.name, Typ[c.kind], c.val)) + } +} + +func defPredeclaredNil() { + def(&Nil{object{name: "nil", typ: Typ[UntypedNil]}}) +} + +// A builtinId is the id of a builtin function. +type builtinId int + +const ( + // universe scope + _Append builtinId = iota + _Cap + _Close + _Complex + _Copy + _Delete + _Imag + _Len + _Make + _New + _Panic + _Print + _Println + _Real + _Recover + + // package unsafe + _Alignof + _Offsetof + _Sizeof + + // testing support + _Assert + _Trace +) + +var predeclaredFuncs = [...]struct { + name string + nargs int + variadic bool + kind exprKind +}{ + _Append: {"append", 1, true, expression}, + _Cap: {"cap", 1, false, expression}, + _Close: {"close", 1, false, statement}, + _Complex: {"complex", 2, false, expression}, + _Copy: {"copy", 2, false, statement}, + _Delete: {"delete", 2, false, statement}, + _Imag: {"imag", 1, false, expression}, + _Len: {"len", 1, false, expression}, + _Make: {"make", 1, true, expression}, + _New: {"new", 1, false, expression}, + _Panic: {"panic", 1, false, statement}, + _Print: {"print", 0, true, statement}, + _Println: {"println", 0, true, statement}, + _Real: {"real", 1, false, expression}, + _Recover: {"recover", 0, false, statement}, + + _Alignof: {"Alignof", 1, false, expression}, + _Offsetof: {"Offsetof", 1, false, expression}, + _Sizeof: {"Sizeof", 1, false, expression}, + + _Assert: {"assert", 1, false, statement}, + _Trace: {"trace", 0, true, statement}, +} + +func defPredeclaredFuncs() { + for i := range predeclaredFuncs { + id := builtinId(i) + if id == _Assert || id == _Trace { + continue // only define these in testing environment + } + def(newBuiltin(id)) + } +} + +// DefPredeclaredTestFuncs defines the assert and trace built-ins. +// These built-ins are intended for debugging and testing of this +// package only. +func DefPredeclaredTestFuncs() { + if Universe.Lookup("assert") != nil { + return // already defined + } + def(newBuiltin(_Assert)) + def(newBuiltin(_Trace)) +} + +func init() { + Universe = NewScope(nil, token.NoPos, token.NoPos, "universe") + Unsafe = NewPackage("unsafe", "unsafe") + Unsafe.complete = true + + defPredeclaredTypes() + defPredeclaredConsts() + defPredeclaredNil() + defPredeclaredFuncs() + + universeIota = Universe.Lookup("iota").(*Const) + universeByte = Universe.Lookup("byte").(*TypeName).typ.(*Basic) + universeRune = Universe.Lookup("rune").(*TypeName).typ.(*Basic) +} + +// Objects with names containing blanks are internal and not entered into +// a scope. Objects with exported names are inserted in the unsafe package +// scope; other objects are inserted in the universe scope. +// +func def(obj Object) { + name := obj.Name() + if strings.Contains(name, " ") { + return // nothing to do + } + // fix Obj link for named types + if typ, ok := obj.Type().(*Named); ok { + typ.obj = obj.(*TypeName) + } + // exported identifiers go into package unsafe + scope := Universe + if obj.Exported() { + scope = Unsafe.scope + // set Pkg field + switch obj := obj.(type) { + case *TypeName: + obj.pkg = Unsafe + case *Builtin: + obj.pkg = Unsafe + default: + unreachable() + } + } + if scope.Insert(obj) != nil { + panic("internal error: double declaration") + } +}