godoc: collect package comments from all package files, not just the first one found

R=r
CC=golang-dev
https://golang.org/cl/1331041

diff --git a/src/pkg/go/doc/doc.go b/src/pkg/go/doc/doc.go
index 44947b63ac9278321c52579980700c897b62751f..b73fd285c1d4964366382fff36d7f542163d6780 100644 (file)
--- a/src/pkg/go/doc/doc.go
+++ b/src/pkg/go/doc/doc.go
@@ -53,6 +53,28 @@ func (doc *docReader) init(pkgName string) {
 }
 
 
+func (doc *docReader) addDoc(comments *ast.CommentGroup) {
+       if doc.doc == nil {
+               // common case: just one package comment
+               doc.doc = comments
+               return
+       }
+
+       // More than one package comment: Usually there will be only
+       // one file with a package comment, but it's better to collect
+       // all comments than drop them on the floor.
+       // (This code isn't particularly clever - no amortized doubling is
+       // used - but this situation occurs rarely and is not time-critical.)
+       n1 := len(doc.doc.List)
+       n2 := len(comments.List)
+       list := make([]*ast.Comment, n1+1+n2) // + 1 for separator line
+       copy(list, doc.doc.List)
+       list[n1] = &ast.Comment{token.Position{}, []byte("//")} // separator line
+       copy(list[n1+1:], comments.List)
+       doc.doc = &ast.CommentGroup{list}
+}
+
+
 func (doc *docReader) addType(decl *ast.GenDecl) {
        spec := decl.Specs[0].(*ast.TypeSpec)
        typ := doc.lookupTypeDoc(spec.Name.Name())
@@ -275,12 +297,7 @@ var (
 func (doc *docReader) addFile(src *ast.File) {
        // add package documentation
        if src.Doc != nil {
-               // TODO(gri) This won't do the right thing if there is more
-               //           than one file with package comments. Consider
-               //           using ast.MergePackageFiles which handles these
-               //           comments correctly (but currently looses BUG(...)
-               //           comments).
-               doc.doc = src.Doc
+               doc.addDoc(src.Doc)
                src.Doc = nil // doc consumed - remove from ast.File node
        }