Move mvdan.cc/sh to v3

vendor/mvdan.cc/sh/v3/shell/source.go

@@ -0,0 +1,57 @@
+// Copyright (c) 2018, Daniel Martí <mvdan@mvdan.cc>
+// See LICENSE for licensing information
+
+package shell
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"mvdan.cc/sh/v3/expand"
+	"mvdan.cc/sh/v3/interp"
+	"mvdan.cc/sh/v3/syntax"
+)
+
+// SourceFile sources a shell file from disk and returns the variables
+// declared in it. It is a convenience function that uses a default shell
+// parser, parses a file from disk, and calls SourceNode.
+//
+// This function should be used with caution, as it can interpret arbitrary
+// code. Untrusted shell programs shoudn't be sourced outside of a sandbox
+// environment.
+func SourceFile(ctx context.Context, path string) (map[string]expand.Variable, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("could not open: %v", err)
+	}
+	defer f.Close()
+	file, err := syntax.NewParser().Parse(f, path)
+	if err != nil {
+		return nil, fmt.Errorf("could not parse: %v", err)
+	}
+	return SourceNode(ctx, file)
+}
+
+// SourceNode sources a shell program from a node and returns the
+// variables declared in it. It accepts the same set of node types that
+// interp/Runner.Run does.
+//
+// This function should be used with caution, as it can interpret arbitrary
+// code. Untrusted shell programs shoudn't be sourced outside of a sandbox
+// environment.
+func SourceNode(ctx context.Context, node syntax.Node) (map[string]expand.Variable, error) {
+	r, _ := interp.New()
+	if err := r.Run(ctx, node); err != nil {
+		return nil, fmt.Errorf("could not run: %v", err)
+	}
+	// delete the internal shell vars that the user is not
+	// interested in
+	delete(r.Vars, "PWD")
+	delete(r.Vars, "UID")
+	delete(r.Vars, "HOME")
+	delete(r.Vars, "PATH")
+	delete(r.Vars, "IFS")
+	delete(r.Vars, "OPTIND")
+	return r.Vars, nil
+}