godoc: don't throw away function documentation

if there are multiple functions (for a package, type)
with the same name

Fixes #642.

R=rsc
CC=golang-dev
https://golang.org/cl/243041

diff --git a/src/pkg/go/doc/doc.go b/src/pkg/go/doc/doc.go
index 1bf496933729b59c86db76011a01c33727e0bd38..5479743bae2e1e0d90d45eec1c3bc40e4b02d095 100644 (file)
--- a/src/pkg/go/doc/doc.go
+++ b/src/pkg/go/doc/doc.go
@@ -147,6 +147,24 @@ func (doc *docReader) addValue(decl *ast.GenDecl) {
 }
 
 
+// Helper function to set the table entry for function f. Makes sure that
+// at least one f with associated documentation is stored in table, if there
+// are multiple f's with the same name.
+func setFunc(table map[string]*ast.FuncDecl, f *ast.FuncDecl) {
+       name := f.Name.Name()
+       if g, exists := table[name]; exists && g.Doc != nil {
+               // a function with the same name has already been registered;
+               // since it has documentation, assume f is simply another
+               // implementation and ignore it
+               // TODO(gri) consider collecting all functions, or at least
+               //           all comments
+               return
+       }
+       // function doesn't exist or has no documentation; use f
+       table[name] = f
+}
+
+
 func (doc *docReader) addFunc(fun *ast.FuncDecl) {
        name := fun.Name.Name()
 
@@ -156,7 +174,7 @@ func (doc *docReader) addFunc(fun *ast.FuncDecl) {
                typ := doc.lookupTypeDoc(baseTypeName(fun.Recv.List[0].Type))
                if typ != nil {
                        // exported receiver type
-                       typ.methods[name] = fun
+                       setFunc(typ.methods, fun)
                }
                // otherwise don't show the method
                // TODO(gri): There may be exported methods of non-exported types
@@ -187,18 +205,18 @@ func (doc *docReader) addFunc(fun *ast.FuncDecl) {
                                if doc.pkgName == "os" && tname == "Error" &&
                                        name != "NewError" && name != "NewSyscallError" {
                                        // not a factory function for os.Error
-                                       doc.funcs[name] = fun // treat as ordinary function
+                                       setFunc(doc.funcs, fun) // treat as ordinary function
                                        return
                                }
 
-                               typ.factories[name] = fun
+                               setFunc(typ.factories, fun)
                                return
                        }
                }
        }
 
        // ordinary function
-       doc.funcs[name] = fun
+       setFunc(doc.funcs, fun)
 }