cmd/api: fix type scrubbing

It wasn't removing names from func parameters for func types,
and it was handling "a, b string" as "string", not "string, string".

Fixes #4688

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7181051

api/go1.txt

@@ -2835,7 +2835,7 @@ pkg go/ast, type Field struct, Doc *CommentGroup
 pkg go/ast, type Field struct, Names []*Ident
 pkg go/ast, type Field struct, Tag *BasicLit
 pkg go/ast, type Field struct, Type Expr
-pkg go/ast, type FieldFilter func(name string, value reflect.Value) bool
+pkg go/ast, type FieldFilter func(string, reflect.Value) bool
 pkg go/ast, type FieldList struct
 pkg go/ast, type FieldList struct, Closing token.Pos
 pkg go/ast, type FieldList struct, List []*Field
@@ -2895,7 +2895,7 @@ pkg go/ast, type ImportSpec struct, Doc *CommentGroup
 pkg go/ast, type ImportSpec struct, EndPos token.Pos
 pkg go/ast, type ImportSpec struct, Name *Ident
 pkg go/ast, type ImportSpec struct, Path *BasicLit
-pkg go/ast, type Importer func(imports map[string]*Object, path string) (pkg *Object, err error)
+pkg go/ast, type Importer func(map[string]*Object, string) (*Object, error)
 pkg go/ast, type IncDecStmt struct
 pkg go/ast, type IncDecStmt struct, Tok token.Token
 pkg go/ast, type IncDecStmt struct, TokPos token.Pos
@@ -3033,7 +3033,7 @@ pkg go/build, type Context struct, GOARCH string
 pkg go/build, type Context struct, GOOS string
 pkg go/build, type Context struct, GOPATH string
 pkg go/build, type Context struct, GOROOT string
-pkg go/build, type Context struct, HasSubdir func(string) (string, bool)
+pkg go/build, type Context struct, HasSubdir func(string, string) (string, bool)
 pkg go/build, type Context struct, IsAbsPath func(string) bool
 pkg go/build, type Context struct, IsDir func(string) bool
 pkg go/build, type Context struct, JoinPath func(...string) string
@@ -3160,7 +3160,7 @@ pkg go/scanner, method (ErrorList) Swap(int, int)
 pkg go/scanner, type Error struct
 pkg go/scanner, type Error struct, Msg string
 pkg go/scanner, type Error struct, Pos token.Position
-pkg go/scanner, type ErrorHandler func(pos token.Position, msg string)
+pkg go/scanner, type ErrorHandler func(token.Position, string)
 pkg go/scanner, type ErrorList []*Error
 pkg go/scanner, type Mode uint
 pkg go/scanner, type Scanner struct
@@ -4808,7 +4808,7 @@ pkg net/http, type Server struct, ReadTimeout time.Duration
 pkg net/http, type Server struct, TLSConfig *tls.Config
 pkg net/http, type Server struct, WriteTimeout time.Duration
 pkg net/http, type Transport struct
-pkg net/http, type Transport struct, Dial func(string) (net.Conn, error)
+pkg net/http, type Transport struct, Dial func(string, string) (net.Conn, error)
 pkg net/http, type Transport struct, DisableCompression bool
 pkg net/http, type Transport struct, DisableKeepAlives bool
 pkg net/http, type Transport struct, MaxIdleConnsPerHost int
@@ -5327,7 +5327,7 @@ pkg path/filepath, func SplitList(string) []string
 pkg path/filepath, func ToSlash(string) string
 pkg path/filepath, func VolumeName(string) string
 pkg path/filepath, func Walk(string, WalkFunc) error
-pkg path/filepath, type WalkFunc func(path string, info os.FileInfo, err error) error
+pkg path/filepath, type WalkFunc func(string, os.FileInfo, error) error
 pkg path/filepath, var ErrBadPattern error
 pkg path/filepath, var SkipDir error
 pkg reflect, const Array Kind
@@ -30127,10 +30127,10 @@ pkg syscall, type Timeval struct
 pkg syscall, var ForkLock sync.RWMutex
 pkg syscall, var SocketDisableIPv6 bool
 pkg testing, func Benchmark(func(*B)) BenchmarkResult
-pkg testing, func Main(func(string) (bool, error), []InternalTest, []InternalBenchmark, []InternalExample)
-pkg testing, func RunBenchmarks(func(string) (bool, error), []InternalBenchmark)
-pkg testing, func RunExamples(func(string) (bool, error), []InternalExample) bool
-pkg testing, func RunTests(func(string) (bool, error), []InternalTest) bool
+pkg testing, func Main(func(string, string) (bool, error), []InternalTest, []InternalBenchmark, []InternalExample)
+pkg testing, func RunBenchmarks(func(string, string) (bool, error), []InternalBenchmark)
+pkg testing, func RunExamples(func(string, string) (bool, error), []InternalExample) bool
+pkg testing, func RunTests(func(string, string) (bool, error), []InternalTest) bool
 pkg testing, func Short() bool
 pkg testing, method (*B) Error(...interface{})
 pkg testing, method (*B) Errorf(string, ...interface{})

src/cmd/api/goapi.go

@@ -879,7 +879,7 @@ func (w *Walker) walkTypeSpec(ts *ast.TypeSpec) {
 	case *ast.InterfaceType:
 		w.walkInterfaceType(name, t)
 	default:
-		w.emitFeature(fmt.Sprintf("type %s %s", name, w.nodeString(ts.Type)))
+		w.emitFeature(fmt.Sprintf("type %s %s", name, w.nodeString(w.namelessType(ts.Type))))
 	}
 }
 
@@ -1120,7 +1120,13 @@ func (w *Walker) namelessFieldList(fl *ast.FieldList) *ast.FieldList {
 	fl2 := &ast.FieldList{}
 	if fl != nil {
 		for _, f := range fl.List {
-			fl2.List = append(fl2.List, w.namelessField(f))
+			repeats := 1
+			if len(f.Names) > 1 {
+				repeats = len(f.Names)
+			}
+			for i := 0; i < repeats; i++ {
+				fl2.List = append(fl2.List, w.namelessField(f))
+			}
 		}
 	}
 	return fl2

src/cmd/api/testdata/src/pkg/p1/golden.txt

@@ -10,6 +10,7 @@ pkg p1, func Bar(int8, int16, int64)
 pkg p1, func Bar1(int8, int16, int64) uint64
 pkg p1, func Bar2(int8, int16, int64) (uint8, uint64)
 pkg p1, func BarE() Error
+pkg p1, func PlainFunc(int, int, string) (*B, error)
 pkg p1, func TakesFunc(func(int) int)
 pkg p1, method (*B) JustOnB()
 pkg p1, method (*B) OnBothTandBPtr()
@@ -37,20 +38,21 @@ pkg p1, type Embedded struct
 pkg p1, type Error interface { Error, Temporary }
 pkg p1, type Error interface, Error() string
 pkg p1, type Error interface, Temporary() bool
-pkg p1, type I interface, unexported methods
+pkg p1, type FuncType func(int, int, string) (*B, error)
 pkg p1, type I interface, Get(string) int64
 pkg p1, type I interface, GetNamed(string) int64
 pkg p1, type I interface, Name() string
 pkg p1, type I interface, PackageTwoMeth()
 pkg p1, type I interface, Set(string, int64)
+pkg p1, type I interface, unexported methods
 pkg p1, type MyInt int
 pkg p1, type Namer interface { Name }
 pkg p1, type Namer interface, Name() string
+pkg p1, type Private interface, X()
+pkg p1, type Private interface, unexported methods
 pkg p1, type Public interface { X, Y }
 pkg p1, type Public interface, X()
 pkg p1, type Public interface, Y()
-pkg p1, type Private interface, unexported methods
-pkg p1, type Private interface, X()
 pkg p1, type S struct
 pkg p1, type S struct, Public *int
 pkg p1, type S struct, PublicTime time.Time

src/cmd/api/testdata/src/pkg/p1/p1.go

@@ -149,8 +149,12 @@ type TPtrExported struct {
 	*Embedded
 }
 
+type FuncType func(x, y int, s string) (b *B, err error)
+
 type Embedded struct{}
 
+func PlainFunc(x, y int, s string) (b *B, err error)
+
 func (*Embedded) OnEmbedded() {}
 
 func (*T) JustOnT()             {}