Vendor in go1.5.1 dependency

* Changes to make vendored packages accept new home.
* Fix go2idl to import vendored packages.

third_party/golang/go/ast/commentmap.go

@@ -0,0 +1,332 @@
+// 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 ast
+
+import (
+	"bytes"
+	"fmt"
+	"k8s.io/kubernetes/third_party/golang/go/token"
+	"sort"
+)
+
+type byPos []*CommentGroup
+
+func (a byPos) Len() int           { return len(a) }
+func (a byPos) Less(i, j int) bool { return a[i].Pos() < a[j].Pos() }
+func (a byPos) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+// sortComments sorts the list of comment groups in source order.
+//
+func sortComments(list []*CommentGroup) {
+	// TODO(gri): Does it make sense to check for sorted-ness
+	//            first (because we know that sorted-ness is
+	//            very likely)?
+	if orderedList := byPos(list); !sort.IsSorted(orderedList) {
+		sort.Sort(orderedList)
+	}
+}
+
+// A CommentMap maps an AST node to a list of comment groups
+// associated with it. See NewCommentMap for a description of
+// the association.
+//
+type CommentMap map[Node][]*CommentGroup
+
+func (cmap CommentMap) addComment(n Node, c *CommentGroup) {
+	list := cmap[n]
+	if len(list) == 0 {
+		list = []*CommentGroup{c}
+	} else {
+		list = append(list, c)
+	}
+	cmap[n] = list
+}
+
+type byInterval []Node
+
+func (a byInterval) Len() int { return len(a) }
+func (a byInterval) Less(i, j int) bool {
+	pi, pj := a[i].Pos(), a[j].Pos()
+	return pi < pj || pi == pj && a[i].End() > a[j].End()
+}
+func (a byInterval) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+// nodeList returns the list of nodes of the AST n in source order.
+//
+func nodeList(n Node) []Node {
+	var list []Node
+	Inspect(n, func(n Node) bool {
+		// don't collect comments
+		switch n.(type) {
+		case nil, *CommentGroup, *Comment:
+			return false
+		}
+		list = append(list, n)
+		return true
+	})
+	// Note: The current implementation assumes that Inspect traverses the
+	//       AST in depth-first and thus _source_ order. If AST traversal
+	//       does not follow source order, the sorting call below will be
+	//       required.
+	// sort.Sort(byInterval(list))
+	return list
+}
+
+// A commentListReader helps iterating through a list of comment groups.
+//
+type commentListReader struct {
+	fset     *token.FileSet
+	list     []*CommentGroup
+	index    int
+	comment  *CommentGroup  // comment group at current index
+	pos, end token.Position // source interval of comment group at current index
+}
+
+func (r *commentListReader) eol() bool {
+	return r.index >= len(r.list)
+}
+
+func (r *commentListReader) next() {
+	if !r.eol() {
+		r.comment = r.list[r.index]
+		r.pos = r.fset.Position(r.comment.Pos())
+		r.end = r.fset.Position(r.comment.End())
+		r.index++
+	}
+}
+
+// A nodeStack keeps track of nested nodes.
+// A node lower on the stack lexically contains the nodes higher on the stack.
+//
+type nodeStack []Node
+
+// push pops all nodes that appear lexically before n
+// and then pushes n on the stack.
+//
+func (s *nodeStack) push(n Node) {
+	s.pop(n.Pos())
+	*s = append((*s), n)
+}
+
+// pop pops all nodes that appear lexically before pos
+// (i.e., whose lexical extent has ended before or at pos).
+// It returns the last node popped.
+//
+func (s *nodeStack) pop(pos token.Pos) (top Node) {
+	i := len(*s)
+	for i > 0 && (*s)[i-1].End() <= pos {
+		top = (*s)[i-1]
+		i--
+	}
+	*s = (*s)[0:i]
+	return top
+}
+
+// NewCommentMap creates a new comment map by associating comment groups
+// of the comments list with the nodes of the AST specified by node.
+//
+// A comment group g is associated with a node n if:
+//
+//   - g starts on the same line as n ends
+//   - g starts on the line immediately following n, and there is
+//     at least one empty line after g and before the next node
+//   - g starts before n and is not associated to the node before n
+//     via the previous rules
+//
+// NewCommentMap tries to associate a comment group to the "largest"
+// node possible: For instance, if the comment is a line comment
+// trailing an assignment, the comment is associated with the entire
+// assignment rather than just the last operand in the assignment.
+//
+func NewCommentMap(fset *token.FileSet, node Node, comments []*CommentGroup) CommentMap {
+	if len(comments) == 0 {
+		return nil // no comments to map
+	}
+
+	cmap := make(CommentMap)
+
+	// set up comment reader r
+	tmp := make([]*CommentGroup, len(comments))
+	copy(tmp, comments) // don't change incoming comments
+	sortComments(tmp)
+	r := commentListReader{fset: fset, list: tmp} // !r.eol() because len(comments) > 0
+	r.next()
+
+	// create node list in lexical order
+	nodes := nodeList(node)
+	nodes = append(nodes, nil) // append sentinel
+
+	// set up iteration variables
+	var (
+		p     Node           // previous node
+		pend  token.Position // end of p
+		pg    Node           // previous node group (enclosing nodes of "importance")
+		pgend token.Position // end of pg
+		stack nodeStack      // stack of node groups
+	)
+
+	for _, q := range nodes {
+		var qpos token.Position
+		if q != nil {
+			qpos = fset.Position(q.Pos()) // current node position
+		} else {
+			// set fake sentinel position to infinity so that
+			// all comments get processed before the sentinel
+			const infinity = 1 << 30
+			qpos.Offset = infinity
+			qpos.Line = infinity
+		}
+
+		// process comments before current node
+		for r.end.Offset <= qpos.Offset {
+			// determine recent node group
+			if top := stack.pop(r.comment.Pos()); top != nil {
+				pg = top
+				pgend = fset.Position(pg.End())
+			}
+			// Try to associate a comment first with a node group
+			// (i.e., a node of "importance" such as a declaration);
+			// if that fails, try to associate it with the most recent
+			// node.
+			// TODO(gri) try to simplify the logic below
+			var assoc Node
+			switch {
+			case pg != nil &&
+				(pgend.Line == r.pos.Line ||
+					pgend.Line+1 == r.pos.Line && r.end.Line+1 < qpos.Line):
+				// 1) comment starts on same line as previous node group ends, or
+				// 2) comment starts on the line immediately after the
+				//    previous node group and there is an empty line before
+				//    the current node
+				// => associate comment with previous node group
+				assoc = pg
+			case p != nil &&
+				(pend.Line == r.pos.Line ||
+					pend.Line+1 == r.pos.Line && r.end.Line+1 < qpos.Line ||
+					q == nil):
+				// same rules apply as above for p rather than pg,
+				// but also associate with p if we are at the end (q == nil)
+				assoc = p
+			default:
+				// otherwise, associate comment with current node
+				if q == nil {
+					// we can only reach here if there was no p
+					// which would imply that there were no nodes
+					panic("internal error: no comments should be associated with sentinel")
+				}
+				assoc = q
+			}
+			cmap.addComment(assoc, r.comment)
+			if r.eol() {
+				return cmap
+			}
+			r.next()
+		}
+
+		// update previous node
+		p = q
+		pend = fset.Position(p.End())
+
+		// update previous node group if we see an "important" node
+		switch q.(type) {
+		case *File, *Field, Decl, Spec, Stmt:
+			stack.push(q)
+		}
+	}
+
+	return cmap
+}
+
+// Update replaces an old node in the comment map with the new node
+// and returns the new node. Comments that were associated with the
+// old node are associated with the new node.
+//
+func (cmap CommentMap) Update(old, new Node) Node {
+	if list := cmap[old]; len(list) > 0 {
+		delete(cmap, old)
+		cmap[new] = append(cmap[new], list...)
+	}
+	return new
+}
+
+// Filter returns a new comment map consisting of only those
+// entries of cmap for which a corresponding node exists in
+// the AST specified by node.
+//
+func (cmap CommentMap) Filter(node Node) CommentMap {
+	umap := make(CommentMap)
+	Inspect(node, func(n Node) bool {
+		if g := cmap[n]; len(g) > 0 {
+			umap[n] = g
+		}
+		return true
+	})
+	return umap
+}
+
+// Comments returns the list of comment groups in the comment map.
+// The result is sorted is source order.
+//
+func (cmap CommentMap) Comments() []*CommentGroup {
+	list := make([]*CommentGroup, 0, len(cmap))
+	for _, e := range cmap {
+		list = append(list, e...)
+	}
+	sortComments(list)
+	return list
+}
+
+func summary(list []*CommentGroup) string {
+	const maxLen = 40
+	var buf bytes.Buffer
+
+	// collect comments text
+loop:
+	for _, group := range list {
+		// Note: CommentGroup.Text() does too much work for what we
+		//       need and would only replace this innermost loop.
+		//       Just do it explicitly.
+		for _, comment := range group.List {
+			if buf.Len() >= maxLen {
+				break loop
+			}
+			buf.WriteString(comment.Text)
+		}
+	}
+
+	// truncate if too long
+	if buf.Len() > maxLen {
+		buf.Truncate(maxLen - 3)
+		buf.WriteString("...")
+	}
+
+	// replace any invisibles with blanks
+	bytes := buf.Bytes()
+	for i, b := range bytes {
+		switch b {
+		case '\t', '\n', '\r':
+			bytes[i] = ' '
+		}
+	}
+
+	return string(bytes)
+}
+
+func (cmap CommentMap) String() string {
+	var buf bytes.Buffer
+	fmt.Fprintln(&buf, "CommentMap {")
+	for node, comment := range cmap {
+		// print name of identifiers; print node type for other nodes
+		var s string
+		if ident, ok := node.(*Ident); ok {
+			s = ident.Name
+		} else {
+			s = fmt.Sprintf("%T", node)
+		}
+		fmt.Fprintf(&buf, "\t%p  %20s:  %s\n", node, s, summary(comment))
+	}
+	fmt.Fprintln(&buf, "}")
+	return buf.String()
+}