[dev.link] cmd/link: convert typelink pass to new style

Change-Id: If861409a5cc4e398496199a89498a141f106f44f
Reviewed-on: https://go-review.googlesource.com/c/go/+/227762
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

src/cmd/link/internal/ld/decodesym2.go

@@ -118,3 +118,14 @@ func decodetypeStructFieldOffsAnon2(ldr *loader.Loader, arch *sys.Arch, symIdx l
 	data := ldr.Data(symIdx)
 	return int64(decodeInuxi(arch, data[off+2*arch.PtrSize:], arch.PtrSize))
 }
+
+// decodetypeStr2 returns the contents of an rtype's str field (a nameOff).
+func decodetypeStr2(ldr *loader.Loader, arch *sys.Arch, symIdx loader.Sym) string {
+	relocs := ldr.Relocs(symIdx)
+	str := decodetypeName2(ldr, symIdx, &relocs, 4*arch.PtrSize+8)
+	data := ldr.Data(symIdx)
+	if data[2*arch.PtrSize+4]&tflagExtraStar != 0 {
+		return str[1:]
+	}
+	return str
+}

src/cmd/link/internal/ld/main.go

@@ -290,14 +290,14 @@ func Main(arch *sys.Arch, theArch Arch) {
 
 	bench.Start("textaddress")
 	ctxt.textaddress()
+	bench.Start("typelink")
+	ctxt.typelink()
 	bench.Start("loadlibfull")
 	ctxt.loadlibfull() // XXX do it here for now
 	bench.Start("pclntab")
 	ctxt.pclntab()
 	bench.Start("findfunctab")
 	ctxt.findfunctab()
-	bench.Start("typelink")
-	ctxt.typelink()
 	bench.Start("symtab")
 	ctxt.symtab()
 	bench.Start("buildinfo")

src/cmd/link/internal/ld/typelink.go

@@ -6,6 +6,7 @@ package ld
 
 import (
 	"cmd/internal/objabi"
+	"cmd/link/internal/loader"
 	"cmd/link/internal/sym"
 	"sort"
 )
@@ -14,7 +15,7 @@ type byTypeStr []typelinkSortKey
 
 type typelinkSortKey struct {
 	TypeStr string
-	Type    *sym.Symbol
+	Type    loader.Sym
 }
 
 func (s byTypeStr) Less(i, j int) bool { return s[i].TypeStr < s[j].TypeStr }
@@ -25,25 +26,27 @@ func (s byTypeStr) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
 // Types that should be added to the typelinks table are marked with the
 // MakeTypelink attribute by the compiler.
 func (ctxt *Link) typelink() {
+	ldr := ctxt.loader
 	typelinks := byTypeStr{}
-	for _, s := range ctxt.Syms.Allsym {
-		if s.Attr.Reachable() && s.Attr.MakeTypelink() {
-			typelinks = append(typelinks, typelinkSortKey{decodetypeStr(ctxt.Arch, s), s})
+	for s := loader.Sym(1); s < loader.Sym(ldr.NSym()); s++ {
+		if ldr.AttrReachable(s) && ldr.IsTypelink(s) {
+			typelinks = append(typelinks, typelinkSortKey{decodetypeStr2(ldr, ctxt.Arch, s), s})
 		}
 	}
 	sort.Sort(typelinks)
 
-	tl := ctxt.Syms.Lookup("runtime.typelink", 0)
-	tl.Type = sym.STYPELINK
-	tl.Attr |= sym.AttrReachable | sym.AttrLocal
-	tl.Size = int64(4 * len(typelinks))
-	tl.P = make([]byte, tl.Size)
-	tl.R = make([]sym.Reloc, len(typelinks))
+	tl := ldr.CreateSymForUpdate("runtime.typelink", 0)
+	tl.SetType(sym.STYPELINK)
+	ldr.SetAttrReachable(tl.Sym(), true)
+	ldr.SetAttrLocal(tl.Sym(), true)
+	tl.SetSize(int64(4 * len(typelinks)))
+	tl.Grow(tl.Size())
+	relocs := tl.AddRelocs(len(typelinks))
 	for i, s := range typelinks {
-		r := &tl.R[i]
-		r.Sym = s.Type
-		r.Off = int32(i * 4)
-		r.Siz = 4
-		r.Type = objabi.R_ADDROFF
+		r := relocs.At2(i)
+		r.SetSym(s.Type)
+		r.SetOff(int32(i * 4))
+		r.SetSiz(4)
+		r.SetType(objabi.R_ADDROFF)
 	}
 }

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

@@ -659,7 +659,9 @@ func (l *Loader) SymType(i Sym) sym.SymKind {
 // Returns the attributes of the i-th symbol.
 func (l *Loader) SymAttr(i Sym) uint8 {
 	if l.IsExternal(i) {
-		// TODO: do something? External symbols have different representation of attributes. For now, ReflectMethod is the only thing matters and it cannot be set by external symbol.
+		// TODO: do something? External symbols have different representation of attributes.
+		// For now, ReflectMethod, NoSplit, GoType, and Typelink are used and they cannot be
+		// set by external symbol.
 		return 0
 	}
 	r, li := l.toLocal(i)
@@ -982,6 +984,11 @@ func (l *Loader) IsGoType(i Sym) bool {
 	return l.SymAttr(i)&goobj2.SymFlagGoType != 0
 }
 
+// Returns whether this symbol should be included in typelink.
+func (l *Loader) IsTypelink(i Sym) bool {
+	return l.SymAttr(i)&goobj2.SymFlagTypelink != 0
+}
+
 // Returns whether this is a "go.itablink.*" symbol.
 func (l *Loader) IsItabLink(i Sym) bool {
 	if _, ok := l.itablink[i]; ok {