[dev.link] cmd/internal/obj: change writer to use new-style accessors

Introduce field setters and use them on the writer side. Now we
are able to eliminate the old-style types.

Change-Id: I650d837328dc02f9be839d16a31812be86721b91
Reviewed-on: https://go-review.googlesource.com/c/go/+/227640
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/goobj2/objfile.go

@@ -245,6 +245,19 @@ func (s *Sym2) ReflectMethod() bool { return s.Flag()&SymFlagReflectMethod != 0
 func (s *Sym2) IsGoType() bool      { return s.Flag()&SymFlagGoType != 0 }
 func (s *Sym2) TopFrame() bool      { return s.Flag()&SymFlagTopFrame != 0 }
 
+func (s *Sym2) SetName(x string, w *Writer) {
+	binary.LittleEndian.PutUint32(s[:], uint32(len(x)))
+	binary.LittleEndian.PutUint32(s[4:], w.stringOff(x))
+}
+
+func (s *Sym2) SetABI(x uint16)   { binary.LittleEndian.PutUint16(s[8:], x) }
+func (s *Sym2) SetType(x uint8)   { s[10] = x }
+func (s *Sym2) SetFlag(x uint8)   { s[11] = x }
+func (s *Sym2) SetSiz(x uint32)   { binary.LittleEndian.PutUint32(s[12:], x) }
+func (s *Sym2) SetAlign(x uint32) { binary.LittleEndian.PutUint32(s[16:], x) }
+
+func (s *Sym2) Write(w *Writer) { w.Bytes(s[:]) }
+
 // Symbol reference.
 type SymRef struct {
 	PkgIdx uint32
@@ -302,6 +315,8 @@ func (r *Reloc2) Set(off int32, size uint8, typ uint8, add int64, sym SymRef) {
 	r.SetSym(sym)
 }
 
+func (r *Reloc2) Write(w *Writer) { w.Bytes(r[:]) }
+
 // Aux symbol info.
 type Aux struct {
 	Type uint8
@@ -335,6 +350,14 @@ func (a *Aux2) Sym() SymRef {
 	return SymRef{binary.LittleEndian.Uint32(a[1:]), binary.LittleEndian.Uint32(a[5:])}
 }
 
+func (a *Aux2) SetType(x uint8) { a[0] = x }
+func (a *Aux2) SetSym(x SymRef) {
+	binary.LittleEndian.PutUint32(a[1:], x.PkgIdx)
+	binary.LittleEndian.PutUint32(a[5:], x.SymIdx)
+}
+
+func (a *Aux2) Write(w *Writer) { w.Bytes(a[:]) }
+
 type Writer struct {
 	wr        *bio.Writer
 	stringMap map[string]uint32
@@ -353,13 +376,17 @@ func (w *Writer) AddString(s string) {
 	w.RawString(s)
 }
 
-func (w *Writer) StringRef(s string) {
+func (w *Writer) stringOff(s string) uint32 {
 	off, ok := w.stringMap[s]
 	if !ok {
 		panic(fmt.Sprintf("writeStringRef: string not added: %q", s))
 	}
+	return off
+}
+
+func (w *Writer) StringRef(s string) {
 	w.Uint32(uint32(len(s)))
-	w.Uint32(off)
+	w.Uint32(w.stringOff(s))
 }
 
 func (w *Writer) RawString(s string) {

src/cmd/internal/obj/objfile2.go

@@ -248,14 +248,13 @@ func (w *writer) Sym(s *LSym) {
 	if s.Func != nil {
 		align = uint32(s.Func.Align)
 	}
-	o := goobj2.Sym{
+	var o goobj2.Sym2
-		Name:  name,
+	o.SetName(name, w.Writer)
-		ABI:   abi,
+	o.SetABI(abi)
-		Type:  uint8(s.Type),
+	o.SetType(uint8(s.Type))
-		Flag:  flag,
+	o.SetFlag(flag)
-		Siz:   uint32(s.Size),
+	o.SetSiz(uint32(s.Size))
-		Align: align,
+	o.SetAlign(align)
-	}
 	o.Write(w.Writer)
 }
 
@@ -271,66 +270,44 @@ func makeSymRef(s *LSym) goobj2.SymRef {
 }
 
 func (w *writer) Reloc(r *Reloc) {
-	o := goobj2.Reloc{
+	var o goobj2.Reloc2
-		Off:  r.Off,
+	o.SetOff(r.Off)
-		Siz:  r.Siz,
+	o.SetSiz(r.Siz)
-		Type: uint8(r.Type),
+	o.SetType(uint8(r.Type))
-		Add:  r.Add,
+	o.SetAdd(r.Add)
-		Sym:  makeSymRef(r.Sym),
+	o.SetSym(makeSymRef(r.Sym))
-	}
+	o.Write(w.Writer)
+}
+
+func (w *writer) aux1(typ uint8, rs *LSym) {
+	var o goobj2.Aux2
+	o.SetType(typ)
+	o.SetSym(makeSymRef(rs))
 	o.Write(w.Writer)
 }
 
 func (w *writer) Aux(s *LSym) {
 	if s.Gotype != nil {
-		o := goobj2.Aux{
+		w.aux1(goobj2.AuxGotype, s.Gotype)
-			Type: goobj2.AuxGotype,
-			Sym:  makeSymRef(s.Gotype),
-		}
-		o.Write(w.Writer)
 	}
 	if s.Func != nil {
-		o := goobj2.Aux{
+		w.aux1(goobj2.AuxFuncInfo, s.Func.FuncInfoSym)
-			Type: goobj2.AuxFuncInfo,
-			Sym:  makeSymRef(s.Func.FuncInfoSym),
-		}
-		o.Write(w.Writer)
 
 		for _, d := range s.Func.Pcln.Funcdata {
-			o := goobj2.Aux{
+			w.aux1(goobj2.AuxFuncdata, d)
-				Type: goobj2.AuxFuncdata,
-				Sym:  makeSymRef(d),
-			}
-			o.Write(w.Writer)
 		}
 
 		if s.Func.dwarfInfoSym != nil && s.Func.dwarfInfoSym.Size != 0 {
-			o := goobj2.Aux{
+			w.aux1(goobj2.AuxDwarfInfo, s.Func.dwarfInfoSym)
-				Type: goobj2.AuxDwarfInfo,
-				Sym:  makeSymRef(s.Func.dwarfInfoSym),
-			}
-			o.Write(w.Writer)
 		}
 		if s.Func.dwarfLocSym != nil && s.Func.dwarfLocSym.Size != 0 {
-			o := goobj2.Aux{
+			w.aux1(goobj2.AuxDwarfLoc, s.Func.dwarfLocSym)
-				Type: goobj2.AuxDwarfLoc,
-				Sym:  makeSymRef(s.Func.dwarfLocSym),
-			}
-			o.Write(w.Writer)
 		}
 		if s.Func.dwarfRangesSym != nil && s.Func.dwarfRangesSym.Size != 0 {
-			o := goobj2.Aux{
+			w.aux1(goobj2.AuxDwarfRanges, s.Func.dwarfRangesSym)
-				Type: goobj2.AuxDwarfRanges,
-				Sym:  makeSymRef(s.Func.dwarfRangesSym),
-			}
-			o.Write(w.Writer)
 		}
 		if s.Func.dwarfDebugLinesSym != nil && s.Func.dwarfDebugLinesSym.Size != 0 {
-			o := goobj2.Aux{
+			w.aux1(goobj2.AuxDwarfLines, s.Func.dwarfDebugLinesSym)
-				Type: goobj2.AuxDwarfLines,
-				Sym:  makeSymRef(s.Func.dwarfDebugLinesSym),
-			}
-			o.Write(w.Writer)
 		}
 	}
 }