[dev.link] cmd/internal/goobj2: move NoSplit to symbol flag

Move NoSplit flag from FuncInfo to symbol flag, so this can be
accessed easily without reading the FuncInfo.

The CFunc flag is never used. Remove.

Change-Id: I8bf4fcb2f209434bb90ccc4987a4c3f28f003323
Reviewed-on: https://go-review.googlesource.com/c/go/+/220058
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

src/cmd/internal/goobj/readnew.go

@@ -149,7 +149,7 @@ func (r *objReader) readNew() {
 		f := &Func{
 			Args:     int64(info.Args),
 			Frame:    int64(info.Locals),
-			NoSplit:  info.NoSplit != 0,
+			NoSplit:  osym.NoSplit(),
 			Leaf:     osym.Leaf(),
 			TopFrame: osym.TopFrame(),
 			PCSP:     Data{int64(pcdataBase + info.Pcsp), int64(info.Pcfile - info.Pcsp)},

src/cmd/internal/goobj2/funcinfo.go

@@ -14,8 +14,6 @@ import (
 //
 // TODO: make each pcdata a separate symbol?
 type FuncInfo struct {
-	NoSplit uint8
-
 	Args   uint32
 	Locals uint32
 
@@ -32,8 +30,6 @@ type FuncInfo struct {
 }
 
 func (a *FuncInfo) Write(w *bytes.Buffer) {
-	w.WriteByte(a.NoSplit)
-
 	var b [4]byte
 	writeUint32 := func(x uint32) {
 		binary.LittleEndian.PutUint32(b[:], x)
@@ -68,9 +64,6 @@ func (a *FuncInfo) Write(w *bytes.Buffer) {
 }
 
 func (a *FuncInfo) Read(b []byte) {
-	a.NoSplit = b[0]
-	b = b[1:]
-
 	readUint32 := func() uint32 {
 		x := binary.LittleEndian.Uint32(b)
 		b = b[4:]

src/cmd/internal/goobj2/objfile.go

@@ -203,7 +203,7 @@ const (
 	SymFlagLocal
 	SymFlagTypelink
 	SymFlagLeaf
-	SymFlagCFunc
+	SymFlagNoSplit
 	SymFlagReflectMethod
 	SymFlagGoType
 	SymFlagTopFrame
@@ -247,7 +247,7 @@ func (s *Sym) Dupok() bool         { return s.Flag&SymFlagDupok != 0 }
 func (s *Sym) Local() bool         { return s.Flag&SymFlagLocal != 0 }
 func (s *Sym) Typelink() bool      { return s.Flag&SymFlagTypelink != 0 }
 func (s *Sym) Leaf() bool          { return s.Flag&SymFlagLeaf != 0 }
-func (s *Sym) CFunc() bool         { return s.Flag&SymFlagCFunc != 0 }
+func (s *Sym) NoSplit() bool       { return s.Flag&SymFlagNoSplit != 0 }
 func (s *Sym) ReflectMethod() bool { return s.Flag&SymFlagReflectMethod != 0 }
 func (s *Sym) IsGoType() bool      { return s.Flag&SymFlagGoType != 0 }
 func (s *Sym) TopFrame() bool      { return s.Flag&SymFlagTopFrame != 0 }

src/cmd/internal/obj/objfile2.go

@@ -229,8 +229,8 @@ func (w *writer) Sym(s *LSym) {
 	if s.Leaf() {
 		flag |= goobj2.SymFlagLeaf
 	}
-	if s.CFunc() {
+	if s.NoSplit() {
-		flag |= goobj2.SymFlagCFunc
+		flag |= goobj2.SymFlagNoSplit
 	}
 	if s.ReflectMethod() {
 		flag |= goobj2.SymFlagReflectMethod
@@ -366,12 +366,7 @@ func genFuncInfoSyms(ctxt *Link) {
 		if s.Func == nil {
 			continue
 		}
-		nosplit := uint8(0)
-		if s.NoSplit() {
-			nosplit = 1
-		}
 		o := goobj2.FuncInfo{
-			NoSplit: nosplit,
 			Args:   uint32(s.Func.Args),
 			Locals: uint32(s.Func.Locals),
 		}

src/cmd/link/internal/loader/loader.go

@@ -940,6 +940,11 @@ func (l *Loader) IsReflectMethod(i Sym) bool {
 	return l.SymAttr(i)&goobj2.SymFlagReflectMethod != 0
 }
 
+// Returns whether the i-th symbol is nosplit.
+func (l *Loader) IsNoSplit(i Sym) bool {
+	return l.SymAttr(i)&goobj2.SymFlagNoSplit != 0
+}
+
 // Returns whether this is a Go type symbol.
 func (l *Loader) IsGoType(i Sym) bool {
 	return l.SymAttr(i)&goobj2.SymFlagGoType != 0
@@ -2189,7 +2194,7 @@ func loadObjFull(l *Loader, r *oReader) {
 		info := goobj2.FuncInfo{}
 		info.Read(b)
 
-		if info.NoSplit != 0 {
+		if osym.NoSplit() {
 			s.Attr |= sym.AttrNoSplit
 		}
 		if osym.ReflectMethod() {