cmd/internal/obj: eliminate LSym.Version

There were only two versions, 0 and 1,
and the only user of version 1 was the assembler,
to indicate that a symbol was static.

Rename LSym.Version to Static,
and add it to LSym.Attributes.
Simplify call-sites.

Passes toolstash-check.

Change-Id: Iabd39918f5019cce78f381d13f0481ae09f3871f
Reviewed-on: https://go-review.googlesource.com/41201
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

src/cmd/asm/internal/asm/parse.go

@@ -585,16 +585,20 @@ func (p *Parser) symbolReference(a *obj.Addr, name string, prefix rune) {
 		a.Type = obj.TYPE_INDIR
 	}
 	// Weirdness with statics: Might now have "<>".
-	isStatic := 0 // TODO: Really a boolean, but ctxt.Lookup wants a "version" integer.
+	isStatic := false
 	if p.peek() == '<' {
-		isStatic = 1
+		isStatic = true
 		p.next()
 		p.get('>')
 	}
 	if p.peek() == '+' || p.peek() == '-' {
 		a.Offset = int64(p.expr())
 	}
-	a.Sym = p.ctxt.Lookup(name, isStatic)
+	if isStatic {
+		a.Sym = p.ctxt.LookupStatic(name)
+	} else {
+		a.Sym = p.ctxt.Lookup(name)
+	}
 	if p.peek() == scanner.EOF {
 		if prefix == 0 && p.isJump {
 			// Symbols without prefix or suffix are jump labels.
@@ -607,7 +611,7 @@ func (p *Parser) symbolReference(a *obj.Addr, name string, prefix rune) {
 	p.get('(')
 	reg := p.get(scanner.Ident).String()
 	p.get(')')
-	p.setPseudoRegister(a, reg, isStatic != 0, prefix)
+	p.setPseudoRegister(a, reg, isStatic, prefix)
 }
 
 // setPseudoRegister sets the NAME field of addr for a pseudo-register reference such as (SB).

src/cmd/compile/internal/gc/obj.go

@@ -266,7 +266,7 @@ func Linksym(s *types.Sym) *obj.LSym {
 		return nil
 	}
 	if s.Lsym == nil {
-		s.Lsym = Ctxt.Lookup(linksymname(s), 0)
+		s.Lsym = Ctxt.Lookup(linksymname(s))
 	}
 	return s.Lsym
 }
@@ -337,7 +337,7 @@ func stringsym(s string) (data *obj.LSym) {
 	const prefix = "go.string."
 	symdataname := prefix + symname
 
-	symdata := Ctxt.Lookup(symdataname, 0)
+	symdata := Ctxt.Lookup(symdataname)
 
 	if !symdata.SeenGlobl() {
 		// string data

src/cmd/compile/internal/gc/pgen.go

@@ -264,7 +264,7 @@ func debuginfo(fnsym *obj.LSym, curfn interface{}) []*dwarf.Var {
 
 		gotype := Linksym(ngotype(n))
 		fnsym.Func.Autom = append(fnsym.Func.Autom, &obj.Auto{
-			Asym:    Ctxt.Lookup(n.Sym.Name, 0),
+			Asym:    Ctxt.Lookup(n.Sym.Name),
 			Aoffset: int32(n.Xoffset),
 			Name:    name,
 			Gotype:  gotype,
@@ -279,7 +279,7 @@ func debuginfo(fnsym *obj.LSym, curfn interface{}) []*dwarf.Var {
 			Name:   n.Sym.Name,
 			Abbrev: abbrev,
 			Offset: int32(offs),
-			Type:   Ctxt.Lookup(typename, 0),
+			Type:   Ctxt.Lookup(typename),
 		})
 	}
 

src/cmd/compile/internal/gc/reflect.go

@@ -447,7 +447,7 @@ func dimportpath(p *types.Pkg) {
 		str = p.Path
 	}
 
-	s := Ctxt.Lookup("type..importpath."+p.Prefix+".", 0)
+	s := Ctxt.Lookup("type..importpath." + p.Prefix + ".")
 	ot := dnameData(s, 0, str, "", nil, false)
 	ggloblLSym(s, int32(ot), obj.DUPOK|obj.RODATA)
 	p.Pathsym = s
@@ -468,7 +468,7 @@ func dgopkgpathLSym(s *obj.LSym, ot int, pkg *types.Pkg) int {
 		// type..importpath.""., which the linker will rewrite using the correct import path.
 		// Every package that imports this one directly defines the symbol.
 		// See also https://groups.google.com/forum/#!topic/golang-dev/myb9s53HxGQ.
-		ns := Ctxt.Lookup(`type..importpath."".`, 0)
+		ns := Ctxt.Lookup(`type..importpath."".`)
 		return dsymptrLSym(s, ot, ns, 0)
 	}
 
@@ -487,7 +487,7 @@ func dgopkgpathOffLSym(s *obj.LSym, ot int, pkg *types.Pkg) int {
 		// type..importpath.""., which the linker will rewrite using the correct import path.
 		// Every package that imports this one directly defines the symbol.
 		// See also https://groups.google.com/forum/#!topic/golang-dev/myb9s53HxGQ.
-		ns := Ctxt.Lookup(`type..importpath."".`, 0)
+		ns := Ctxt.Lookup(`type..importpath."".`)
 		return dsymptrOffLSym(s, ot, ns, 0)
 	}
 
@@ -591,7 +591,7 @@ func dname(name, tag string, pkg *types.Pkg, exported bool) *obj.LSym {
 		sname = fmt.Sprintf(`%s"".%d`, sname, dnameCount)
 		dnameCount++
 	}
-	s := Ctxt.Lookup(sname, 0)
+	s := Ctxt.Lookup(sname)
 	if len(s.P) > 0 {
 		return s
 	}
@@ -1478,7 +1478,7 @@ func dumptypestructs() {
 	// process ptabs
 	if localpkg.Name == "main" && len(ptabs) > 0 {
 		ot := 0
-		s := Ctxt.Lookup("go.plugin.tabs", 0)
+		s := Ctxt.Lookup("go.plugin.tabs")
 		for _, p := range ptabs {
 			// Dump ptab symbol into go.pluginsym package.
 			//
@@ -1493,7 +1493,7 @@ func dumptypestructs() {
 		ggloblLSym(s, int32(ot), int16(obj.RODATA))
 
 		ot = 0
-		s = Ctxt.Lookup("go.plugin.exports", 0)
+		s = Ctxt.Lookup("go.plugin.exports")
 		for _, p := range ptabs {
 			ot = dsymptrLSym(s, ot, Linksym(p.s), 0)
 		}

src/cmd/compile/internal/ssa/export_test.go

@@ -114,7 +114,7 @@ func (DummyFrontend) Line(_ src.XPos) string {
 func (DummyFrontend) AllocFrame(f *Func) {
 }
 func (d DummyFrontend) Syslook(s string) *obj.LSym {
-	return d.ctxt.Lookup(s, 0)
+	return d.ctxt.Lookup(s)
 }
 func (DummyFrontend) UseWriteBarrier() bool {
 	return true // only writebarrier_test cares

src/cmd/internal/obj/arm/asm5.go

@@ -1314,12 +1314,12 @@ func buildop(ctxt *obj.Link) {
 		return
 	}
 
-	deferreturn = ctxt.Lookup("runtime.deferreturn", 0)
+	deferreturn = ctxt.Lookup("runtime.deferreturn")
 
-	symdiv = ctxt.Lookup("_div", 0)
-	symdivu = ctxt.Lookup("_divu", 0)
-	symmod = ctxt.Lookup("_mod", 0)
-	symmodu = ctxt.Lookup("_modu", 0)
+	symdiv = ctxt.Lookup("_div")
+	symdivu = ctxt.Lookup("_divu")
+	symmod = ctxt.Lookup("_mod")
+	symmodu = ctxt.Lookup("_modu")
 
 	var n int
 

src/cmd/internal/obj/arm/obj5.go

@@ -66,7 +66,7 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 			if objabi.GOARM < 7 {
 				// Replace it with BL runtime.read_tls_fallback(SB) for ARM CPUs that lack the tls extension.
 				if progedit_tlsfallback == nil {
-					progedit_tlsfallback = ctxt.Lookup("runtime.read_tls_fallback", 0)
+					progedit_tlsfallback = ctxt.Lookup("runtime.read_tls_fallback")
 				}
 
 				// MOVW	LR, R11
@@ -136,9 +136,9 @@ func (c *ctxt5) rewriteToUseGot(p *obj.Prog) {
 		//     CALL (R9)
 		var sym *obj.LSym
 		if p.As == obj.ADUFFZERO {
-			sym = c.ctxt.Lookup("runtime.duffzero", 0)
+			sym = c.ctxt.Lookup("runtime.duffzero")
 		} else {
-			sym = c.ctxt.Lookup("runtime.duffcopy", 0)
+			sym = c.ctxt.Lookup("runtime.duffcopy")
 		}
 		offset := p.To.Offset
 		p.As = AMOVW
@@ -637,7 +637,7 @@ func (c *ctxt5) softfloat() {
 		return
 	}
 
-	symsfloat := c.ctxt.Lookup("_sfloat", 0)
+	symsfloat := c.ctxt.Lookup("_sfloat")
 
 	wasfloat := 0
 	for p := c.cursym.Func.Text; p != nil; p = p.Link {
@@ -846,7 +846,7 @@ func (c *ctxt5) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 	case !c.cursym.Func.Text.From.Sym.NeedCtxt():
 		morestack = "runtime.morestack_noctxt"
 	}
-	call.To.Sym = c.ctxt.Lookup(morestack, 0)
+	call.To.Sym = c.ctxt.Lookup(morestack)
 
 	// B start
 	b := obj.Appendp(call, c.newprog)

src/cmd/internal/obj/arm64/obj7.go

@@ -208,7 +208,7 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 	case !c.cursym.Func.Text.From.Sym.NeedCtxt():
 		morestack = "runtime.morestack_noctxt"
 	}
-	call.To.Sym = c.ctxt.Lookup(morestack, 0)
+	call.To.Sym = c.ctxt.Lookup(morestack)
 
 	// B	start
 	jmp := obj.Appendp(call, c.newprog)
@@ -333,9 +333,9 @@ func (c *ctxt7) rewriteToUseGot(p *obj.Prog) {
 		//     CALL REGTMP
 		var sym *obj.LSym
 		if p.As == obj.ADUFFZERO {
-			sym = c.ctxt.Lookup("runtime.duffzero", 0)
+			sym = c.ctxt.Lookup("runtime.duffzero")
 		} else {
-			sym = c.ctxt.Lookup("runtime.duffcopy", 0)
+			sym = c.ctxt.Lookup("runtime.duffcopy")
 		}
 		offset := p.To.Offset
 		p.As = AMOVD

src/cmd/internal/obj/line_test.go

@@ -13,7 +13,7 @@ import (
 func TestLinkgetlineFromPos(t *testing.T) {
 	ctxt := new(Link)
 	ctxt.hash = make(map[string]*LSym)
-	ctxt.vhash = make(map[string]*LSym)
+	ctxt.statichash = make(map[string]*LSym)
 
 	afile := src.NewFileBase("a.go", "a.go")
 	bfile := src.NewFileBase("b.go", "/foo/bar/b.go")

src/cmd/internal/obj/link.go

@@ -310,7 +310,6 @@ const (
 type LSym struct {
 	Name string
 	Type objabi.SymKind
-	Version int16
 	Attribute
 
 	RefIdx int // Index of this symbol in the symbol reference list.
@@ -347,6 +346,7 @@ const (
 	AttrNoFrame
 	AttrSeenGlobl
 	AttrOnList
+	AttrStatic
 
 	// MakeTypelink means that the type should have an entry in the typelink table.
 	AttrMakeTypelink
@@ -380,6 +380,7 @@ func (a Attribute) Local() bool         { return a&AttrLocal != 0 }
 func (a Attribute) Wrapper() bool       { return a&AttrWrapper != 0 }
 func (a Attribute) NeedCtxt() bool      { return a&AttrNeedCtxt != 0 }
 func (a Attribute) NoFrame() bool       { return a&AttrNoFrame != 0 }
+func (a Attribute) Static() bool        { return a&AttrStatic != 0 }
 
 func (a *Attribute) Set(flag Attribute, value bool) {
 	if value {
@@ -405,6 +406,7 @@ var textAttrStrings = [...]struct {
 	{bit: AttrWrapper, s: "WRAPPER"},
 	{bit: AttrNeedCtxt, s: "NEEDCTXT"},
 	{bit: AttrNoFrame, s: "NOFRAME"},
+	{bit: AttrStatic, s: "STATIC"},
 }
 
 // TextAttrString formats a for printing in as part of a TEXT prog.
@@ -480,8 +482,8 @@ type Link struct {
 	Flag_optimize bool
 	Bso           *bufio.Writer
 	Pathname      string
-	hash          map[string]*LSym // name -> sym mapping for version == 0
-	vhash         map[string]*LSym // name -> sym mapping for version == 1
+	hash          map[string]*LSym // name -> sym mapping
+	statichash    map[string]*LSym // name -> sym mapping for static syms
 	PosTable      src.PosTable
 	InlTree       InlTree // global inlining tree used by gc/inl.go
 	Imports       []string

src/cmd/internal/obj/mips/obj0.go

@@ -759,11 +759,11 @@ func (c *ctxt0) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 	p.As = AJAL
 	p.To.Type = obj.TYPE_BRANCH
 	if c.cursym.CFunc() {
-		p.To.Sym = c.ctxt.Lookup("runtime.morestackc", 0)
+		p.To.Sym = c.ctxt.Lookup("runtime.morestackc")
 	} else if !c.cursym.Func.Text.From.Sym.NeedCtxt() {
-		p.To.Sym = c.ctxt.Lookup("runtime.morestack_noctxt", 0)
+		p.To.Sym = c.ctxt.Lookup("runtime.morestack_noctxt")
 	} else {
-		p.To.Sym = c.ctxt.Lookup("runtime.morestack", 0)
+		p.To.Sym = c.ctxt.Lookup("runtime.morestack")
 	}
 	p.Mark |= BRANCH
 

src/cmd/internal/obj/objfile.go

@@ -151,17 +151,13 @@ func (w *objWriter) writeRef(s *LSym, isPath bool) {
 		return
 	}
 	var m map[string]int
-	switch s.Version {
-	case 0:
+	if !s.Static() {
 		m = w.refIdx
-	case 1:
+	} else {
 		m = w.vrefIdx
-	default:
-		log.Fatalf("%s: invalid version number %d", s.Name, s.Version)
 	}
 
-	idx := m[s.Name]
-	if idx != 0 {
+	if idx := m[s.Name]; idx != 0 {
 		s.RefIdx = idx
 		return
 	}
@@ -171,7 +167,12 @@ func (w *objWriter) writeRef(s *LSym, isPath bool) {
 	} else {
 		w.writeString(s.Name)
 	}
-	w.writeInt(int64(s.Version))
+	// Write "version".
+	if s.Static() {
+		w.writeInt(1)
+	} else {
+		w.writeInt(0)
+	}
 	w.nRefs++
 	s.RefIdx = w.nRefs
 	m[s.Name] = w.nRefs
@@ -194,13 +195,13 @@ func (w *objWriter) writeRefs(s *LSym) {
 			w.writeRef(d, false)
 		}
 		for _, f := range pc.File {
-			fsym := w.ctxt.Lookup(f, 0)
+			fsym := w.ctxt.Lookup(f)
 			w.writeRef(fsym, true)
 		}
 		for _, call := range pc.InlTree.nodes {
 			w.writeRef(call.Func, false)
 			f, _ := linkgetlineFromPos(w.ctxt, call.Pos)
-			fsym := w.ctxt.Lookup(f, 0)
+			fsym := w.ctxt.Lookup(f)
 			w.writeRef(fsym, true)
 		}
 	}
@@ -209,12 +210,12 @@ func (w *objWriter) writeRefs(s *LSym) {
 func (w *objWriter) writeSymDebug(s *LSym) {
 	ctxt := w.ctxt
 	fmt.Fprintf(ctxt.Bso, "%s ", s.Name)
-	if s.Version != 0 {
-		fmt.Fprintf(ctxt.Bso, "v=%d ", s.Version)
-	}
 	if s.Type != 0 {
 		fmt.Fprintf(ctxt.Bso, "%v ", s.Type)
 	}
+	if s.Static() {
+		fmt.Fprint(ctxt.Bso, "static ")
+	}
 	if s.DuplicateOK() {
 		fmt.Fprintf(ctxt.Bso, "dupok ")
 	}
@@ -364,14 +365,14 @@ func (w *objWriter) writeSym(s *LSym) {
 	}
 	w.writeInt(int64(len(pc.File)))
 	for _, f := range pc.File {
-		fsym := ctxt.Lookup(f, 0)
+		fsym := ctxt.Lookup(f)
 		w.writeRefIndex(fsym)
 	}
 	w.writeInt(int64(len(pc.InlTree.nodes)))
 	for _, call := range pc.InlTree.nodes {
 		w.writeInt(int64(call.Parent))
 		f, l := linkgetlineFromPos(w.ctxt, call.Pos)
-		fsym := ctxt.Lookup(f, 0)
+		fsym := ctxt.Lookup(f)
 		w.writeRefIndex(fsym)
 		w.writeInt(int64(l))
 		w.writeRefIndex(call.Func)
@@ -456,7 +457,7 @@ func (ctxt *Link) dwarfSym(s *LSym) *LSym {
 		ctxt.Diag("dwarfSym of non-TEXT %v", s)
 	}
 	if s.Func.dwarfSym == nil {
-		s.Func.dwarfSym = ctxt.Lookup(dwarf.InfoPrefix+s.Name, int(s.Version))
+		s.Func.dwarfSym = ctxt.LookupDerived(s, dwarf.InfoPrefix+s.Name)
 	}
 	return s.Func.dwarfSym
 }
@@ -472,5 +473,5 @@ func (ctxt *Link) populateDWARF(curfn interface{}, s *LSym) {
 	if ctxt.DebugInfo != nil {
 		vars = ctxt.DebugInfo(s, curfn)
 	}
-	dwarf.PutFunc(dwCtxt{ctxt}, dsym, s.Name, s.Version == 0, s, s.Size, vars)
+	dwarf.PutFunc(dwCtxt{ctxt}, dsym, s.Name, !s.Static(), s, s.Size, vars)
 }

src/cmd/internal/obj/plist.go

@@ -58,7 +58,7 @@ func Flushplist(ctxt *Link, plist *Plist, newprog ProgAlloc) {
 				if p.From.Type != TYPE_CONST || p.From.Offset != objabi.FUNCDATA_ArgsPointerMaps {
 					ctxt.Diag("FUNCDATA use of go_args_stackmap(SB) without FUNCDATA_ArgsPointerMaps")
 				}
-				p.To.Sym = ctxt.Lookup(fmt.Sprintf("%s.args_stackmap", curtext.Name), int(curtext.Version))
+				p.To.Sym = ctxt.LookupDerived(curtext, curtext.Name+".args_stackmap")
 			}
 
 		}
@@ -95,7 +95,7 @@ func Flushplist(ctxt *Link, plist *Plist, newprog ProgAlloc) {
 			p.From.Offset = objabi.FUNCDATA_ArgsPointerMaps
 			p.To.Type = TYPE_MEM
 			p.To.Name = NAME_EXTERN
-			p.To.Sym = ctxt.Lookup(fmt.Sprintf("%s.args_stackmap", s.Name), int(s.Version))
+			p.To.Sym = ctxt.LookupDerived(s, s.Name+".args_stackmap")
 		}
 	}
 

src/cmd/internal/obj/ppc64/asm9.go

@@ -2292,7 +2292,7 @@ func (c *ctxt9) asmout(p *obj.Prog, o *Optab, out []uint32) {
 				// that knows the name of the tls variable. Possibly
 				// we could add some assembly syntax so that the name
 				// of the variable does not have to be assumed.
-				rel.Sym = c.ctxt.Lookup("runtime.tls_g", 0)
+				rel.Sym = c.ctxt.Lookup("runtime.tls_g")
 				rel.Type = objabi.R_POWER_TLS
 			}
 			o1 = AOP_RRR(c.opstorex(p.As), uint32(p.From.Reg), uint32(p.To.Index), uint32(r))
@@ -2323,7 +2323,7 @@ func (c *ctxt9) asmout(p *obj.Prog, o *Optab, out []uint32) {
 				rel := obj.Addrel(c.cursym)
 				rel.Off = int32(c.pc)
 				rel.Siz = 4
-				rel.Sym = c.ctxt.Lookup("runtime.tls_g", 0)
+				rel.Sym = c.ctxt.Lookup("runtime.tls_g")
 				rel.Type = objabi.R_POWER_TLS
 			}
 			o1 = AOP_RRR(c.oploadx(p.As), uint32(p.To.Reg), uint32(p.From.Index), uint32(r))

src/cmd/internal/obj/ppc64/obj9.go

@@ -119,9 +119,9 @@ func (c *ctxt9) rewriteToUseGot(p *obj.Prog) {
 		//     BL (CTR)
 		var sym *obj.LSym
 		if p.As == obj.ADUFFZERO {
-			sym = c.ctxt.Lookup("runtime.duffzero", 0)
+			sym = c.ctxt.Lookup("runtime.duffzero")
 		} else {
-			sym = c.ctxt.Lookup("runtime.duffcopy", 0)
+			sym = c.ctxt.Lookup("runtime.duffcopy")
 		}
 		offset := p.To.Offset
 		p.As = AMOVD
@@ -489,7 +489,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 				rel := obj.Addrel(c.cursym)
 				rel.Off = 0
 				rel.Siz = 8
-				rel.Sym = c.ctxt.Lookup(".TOC.", 0)
+				rel.Sym = c.ctxt.Lookup(".TOC.")
 				rel.Type = objabi.R_ADDRPOWER_PCREL
 			}
 
@@ -950,11 +950,11 @@ func (c *ctxt9) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
 
 	var morestacksym *obj.LSym
 	if c.cursym.CFunc() {
-		morestacksym = c.ctxt.Lookup("runtime.morestackc", 0)
+		morestacksym = c.ctxt.Lookup("runtime.morestackc")
 	} else if !c.cursym.Func.Text.From.Sym.NeedCtxt() {
-		morestacksym = c.ctxt.Lookup("runtime.morestack_noctxt", 0)
+		morestacksym = c.ctxt.Lookup("runtime.morestack_noctxt")
 	} else {
-		morestacksym = c.ctxt.Lookup("runtime.morestack", 0)
+		morestacksym = c.ctxt.Lookup("runtime.morestack")
 	}
 
 	if c.ctxt.Flag_shared {

src/cmd/internal/obj/s390x/objz.go

@@ -682,11 +682,11 @@ func (c *ctxtz) stacksplitPost(p *obj.Prog, pPre *obj.Prog, pPreempt *obj.Prog,
 	p.As = ABL
 	p.To.Type = obj.TYPE_BRANCH
 	if c.cursym.CFunc() {
-		p.To.Sym = c.ctxt.Lookup("runtime.morestackc", 0)
+		p.To.Sym = c.ctxt.Lookup("runtime.morestackc")
 	} else if !c.cursym.Func.Text.From.Sym.NeedCtxt() {
-		p.To.Sym = c.ctxt.Lookup("runtime.morestack_noctxt", 0)
+		p.To.Sym = c.ctxt.Lookup("runtime.morestack_noctxt")
 	} else {
-		p.To.Sym = c.ctxt.Lookup("runtime.morestack", 0)
+		p.To.Sym = c.ctxt.Lookup("runtime.morestack")
 	}
 
 	// BR	start

src/cmd/internal/obj/sizeof_test.go

@@ -23,7 +23,7 @@ func TestSizeof(t *testing.T) {
 		_64bit uintptr     // size on 64bit platforms
 	}{
 		{Addr{}, 32, 48},
-		{LSym{}, 60, 104},
+		{LSym{}, 56, 104},
 		{Prog{}, 124, 184},
 	}
 

src/cmd/internal/obj/sym.go

@@ -41,7 +41,7 @@ import (
 func Linknew(arch *LinkArch) *Link {
 	ctxt := new(Link)
 	ctxt.hash = make(map[string]*LSym)
-	ctxt.vhash = make(map[string]*LSym)
+	ctxt.statichash = make(map[string]*LSym)
 	ctxt.Arch = arch
 	ctxt.Pathname = objabi.WorkingDir()
 
@@ -55,40 +55,51 @@ func Linknew(arch *LinkArch) *Link {
 	return ctxt
 }
 
-// Lookup looks up the symbol with name name and version v.
-// If it does not exist, it creates it.
-func (ctxt *Link) Lookup(name string, v int) *LSym {
-	return ctxt.LookupInit(name, v, nil)
+// LookupDerived looks up or creates the symbol with name name derived from symbol s.
+// The resulting symbol will be static iff s is.
+func (ctxt *Link) LookupDerived(s *LSym, name string) *LSym {
+	if s.Static() {
+		return ctxt.LookupStatic(name)
+	}
+	return ctxt.Lookup(name)
 }
 
-// LookupInit looks up the symbol with name name and version v.
-// If it does not exist, it creates it and passes it to initfn for one-time initialization.
-func (ctxt *Link) LookupInit(name string, v int, init func(s *LSym)) *LSym {
-	var m map[string]*LSym
-	switch v {
-	case 0:
-		m = ctxt.hash
-	case 1:
-		m = ctxt.vhash
-	default:
-		ctxt.Diag("LookupInit: bad version %d", v)
+// LookupStatic looks up the static symbol with name name.
+// If it does not exist, it creates it.
+func (ctxt *Link) LookupStatic(name string) *LSym {
+	s := ctxt.statichash[name]
+	if s == nil {
+		s = &LSym{Name: name, Attribute: AttrStatic}
+		ctxt.statichash[name] = s
 	}
-	if s := m[name]; s != nil {
 	return s
-	}
+}
 
-	s := &LSym{Name: name, Version: int16(v)}
-	m[name] = s
+// Lookup looks up the symbol with name name.
+// If it does not exist, it creates it.
+func (ctxt *Link) Lookup(name string) *LSym {
+	return ctxt.LookupInit(name, nil)
+}
+
+// LookupInit looks up the symbol with name name.
+// If it does not exist, it creates it and
+// passes it to init for one-time initialization.
+func (ctxt *Link) LookupInit(name string, init func(s *LSym)) *LSym {
+	s := ctxt.hash[name]
+	if s == nil {
+		s = &LSym{Name: name}
+		ctxt.hash[name] = s
 		if init != nil {
 			init(s)
 		}
+	}
 	return s
 }
 
 func (ctxt *Link) Float32Sym(f float32) *LSym {
 	i := math.Float32bits(f)
 	name := fmt.Sprintf("$f32.%08x", i)
-	return ctxt.LookupInit(name, 0, func(s *LSym) {
+	return ctxt.LookupInit(name, func(s *LSym) {
 		s.Size = 4
 		s.Set(AttrLocal, true)
 	})
@@ -97,7 +108,7 @@ func (ctxt *Link) Float32Sym(f float32) *LSym {
 func (ctxt *Link) Float64Sym(f float64) *LSym {
 	i := math.Float64bits(f)
 	name := fmt.Sprintf("$f64.%016x", i)
-	return ctxt.LookupInit(name, 0, func(s *LSym) {
+	return ctxt.LookupInit(name, func(s *LSym) {
 		s.Size = 8
 		s.Set(AttrLocal, true)
 	})
@@ -105,7 +116,7 @@ func (ctxt *Link) Float64Sym(f float64) *LSym {
 
 func (ctxt *Link) Int64Sym(i int64) *LSym {
 	name := fmt.Sprintf("$i64.%016x", uint64(i))
-	return ctxt.LookupInit(name, 0, func(s *LSym) {
+	return ctxt.LookupInit(name, func(s *LSym) {
 		s.Size = 8
 		s.Set(AttrLocal, true)
 	})

src/cmd/internal/obj/x86/asm6.go

@@ -1977,9 +1977,9 @@ func instinit(ctxt *obj.Link) {
 
 	switch ctxt.Headtype {
 	case objabi.Hplan9:
-		plan9privates = ctxt.Lookup("_privates", 0)
+		plan9privates = ctxt.Lookup("_privates")
 	case objabi.Hnacl:
-		deferreturn = ctxt.Lookup("runtime.deferreturn", 0)
+		deferreturn = ctxt.Lookup("runtime.deferreturn")
 	}
 
 	for i := 1; optab[i].as != 0; i++ {
@@ -4093,7 +4093,7 @@ func (asmbuf *AsmBuf) doasm(ctxt *obj.Link, cursym *obj.LSym, p *obj.Prog) {
 								r.Off = int32(p.Pc + int64(asmbuf.Len()))
 								r.Type = objabi.R_CALL
 								r.Siz = 4
-								r.Sym = ctxt.Lookup("__x86.get_pc_thunk."+strings.ToLower(rconv(int(dst))), 0)
+								r.Sym = ctxt.Lookup("__x86.get_pc_thunk." + strings.ToLower(rconv(int(dst))))
 								asmbuf.PutInt32(0)
 
 								asmbuf.Put2(0x8B, byte(2<<6|reg[dst]|(reg[dst]<<3)))

src/cmd/internal/obj/x86/obj6.go

@@ -325,9 +325,9 @@ func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 		//     CALL $reg
 		var sym *obj.LSym
 		if p.As == obj.ADUFFZERO {
-			sym = ctxt.Lookup("runtime.duffzero", 0)
+			sym = ctxt.Lookup("runtime.duffzero")
 		} else {
-			sym = ctxt.Lookup("runtime.duffcopy", 0)
+			sym = ctxt.Lookup("runtime.duffcopy")
 		}
 		offset := p.To.Offset
 		p.As = mov
@@ -428,7 +428,7 @@ func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 		p1.As = ALEAL
 		p1.From.Type = obj.TYPE_MEM
 		p1.From.Name = obj.NAME_STATIC
-		p1.From.Sym = ctxt.Lookup("_GLOBAL_OFFSET_TABLE_", 0)
+		p1.From.Sym = ctxt.Lookup("_GLOBAL_OFFSET_TABLE_")
 		p1.To.Type = obj.TYPE_REG
 		p1.To.Reg = REG_BX
 
@@ -536,7 +536,7 @@ func rewriteToPcrel(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 	r.RegTo2 = 1
 	q.As = obj.ACALL
 	thunkname := "__x86.get_pc_thunk." + strings.ToLower(rconv(int(dst)))
-	q.To.Sym = ctxt.LookupInit(thunkname, 0, func(s *obj.LSym) { s.Set(obj.AttrLocal, true) })
+	q.To.Sym = ctxt.LookupInit(thunkname, func(s *obj.LSym) { s.Set(obj.AttrLocal, true) })
 	q.To.Type = obj.TYPE_MEM
 	q.To.Name = obj.NAME_EXTERN
 	r.As = p.As
@@ -1154,7 +1154,7 @@ func stacksplit(ctxt *obj.Link, cursym *obj.LSym, p *obj.Prog, newprog obj.ProgA
 	case !cursym.Func.Text.From.Sym.NeedCtxt():
 		morestack = "runtime.morestack_noctxt"
 	}
-	call.To.Sym = ctxt.Lookup(morestack, 0)
+	call.To.Sym = ctxt.Lookup(morestack)
 	// When compiling 386 code for dynamic linking, the call needs to be adjusted
 	// to follow PIC rules. This in turn can insert more instructions, so we need
 	// to keep track of the start of the call (where the jump will be to) and the