cmd/link: convert textp into a slice

Updates #15374

Change-Id: I3ea715735862fe9550b88d7a29def6cb9d4419a6
Reviewed-on: https://go-review.googlesource.com/22243
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>

src/cmd/link/internal/amd64/asm.go

@@ -86,12 +86,7 @@ func gentext() {
 	Addcall(ld.Ctxt, initfunc, addmoduledata)
 	//    c:	c3                   	retq
 	o(0xc3)
-	if ld.Ctxt.Etextp != nil {
-		ld.Ctxt.Etextp.Next = initfunc
-	} else {
-		ld.Ctxt.Textp = initfunc
-	}
-	ld.Ctxt.Etextp = initfunc
+	ld.Ctxt.Textp = append(ld.Ctxt.Textp, initfunc)
 	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
 	initarray_entry.Attr |= ld.AttrReachable
 	initarray_entry.Attr |= ld.AttrLocal

src/cmd/link/internal/arm/asm.go

@@ -95,12 +95,7 @@ func gentext() {
 	rel.Type = obj.R_PCREL
 	rel.Add = 4
 
-	if ld.Ctxt.Etextp != nil {
-		ld.Ctxt.Etextp.Next = initfunc
-	} else {
-		ld.Ctxt.Textp = initfunc
-	}
-	ld.Ctxt.Etextp = initfunc
+	ld.Ctxt.Textp = append(ld.Ctxt.Textp, initfunc)
 	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
 	initarray_entry.Attr |= ld.AttrReachable
 	initarray_entry.Attr |= ld.AttrLocal

src/cmd/link/internal/arm64/asm.go

@@ -78,12 +78,7 @@ func gentext() {
 	rel.Sym = ld.Linklookup(ld.Ctxt, "runtime.addmoduledata", 0)
 	rel.Type = obj.R_CALLARM64 // Really should be R_AARCH64_JUMP26 but doesn't seem to make any difference
 
-	if ld.Ctxt.Etextp != nil {
-		ld.Ctxt.Etextp.Next = initfunc
-	} else {
-		ld.Ctxt.Textp = initfunc
-	}
-	ld.Ctxt.Etextp = initfunc
+	ld.Ctxt.Textp = append(ld.Ctxt.Textp, initfunc)
 	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
 	initarray_entry.Attr |= ld.AttrReachable
 	initarray_entry.Attr |= ld.AttrLocal

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

@@ -648,7 +648,7 @@ func reloc() {
 	}
 	Bso.Flush()
 
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for _, s := range Ctxt.Textp {
 		relocsym(s)
 	}
 	for _, sym := range datap {
@@ -724,7 +724,7 @@ func dynreloc(data *[obj.SXREF][]*LSym) {
 	}
 	Bso.Flush()
 
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for _, s := range Ctxt.Textp {
 		dynrelocsym(s)
 	}
 	for _, syms := range data {
@@ -791,7 +791,7 @@ func Codeblk(addr int64, size int64) {
 		fmt.Fprintf(Bso, "codeblk [%#x,%#x) at offset %#x\n", addr, addr+size, Cpos())
 	}
 
-	blk(Ctxt.Textp, addr, size)
+	blkSlice(Ctxt.Textp, addr, size)
 
 	/* again for printing */
 	if Debug['a'] == 0 {
@@ -799,7 +799,7 @@ func Codeblk(addr int64, size int64) {
 	}
 
 	var sym *LSym
-	for sym = Ctxt.Textp; sym != nil; sym = sym.Next {
+	for _, sym = range Ctxt.Textp {
 		if !sym.Attr.Reachable() {
 			continue
 		}
@@ -1893,8 +1893,9 @@ func textbuildid() {
 	sym.P = []byte(data)
 	sym.Size = int64(len(sym.P))
 
-	sym.Next = Ctxt.Textp
-	Ctxt.Textp = sym
+	Ctxt.Textp = append(Ctxt.Textp, nil)
+	copy(Ctxt.Textp[1:], Ctxt.Textp)
+	Ctxt.Textp[0] = sym
 }
 
 // assign addresses to text
@@ -1914,7 +1915,7 @@ func textaddress() {
 	}
 	va := uint64(INITTEXT)
 	sect.Vaddr = va
-	for sym := Ctxt.Textp; sym != nil; sym = sym.Next {
+	for _, sym := range Ctxt.Textp {
 		sym.Sect = sect
 		if sym.Type&obj.SSUB != 0 {
 			continue

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

@@ -119,25 +119,13 @@ func deadcode(ctxt *Link) {
 	}
 
 	// Remove dead text but keep file information (z symbols).
-	var last *LSym
-	for s := ctxt.Textp; s != nil; s = s.Next {
-		if !s.Attr.Reachable() {
-			continue
+	textp := make([]*LSym, 0, len(ctxt.Textp))
+	for _, s := range ctxt.Textp {
+		if s.Attr.Reachable() {
+			textp = append(textp, s)
 		}
-		if last == nil {
-			ctxt.Textp = s
-		} else {
-			last.Next = s
-		}
-		last = s
-	}
-	if last == nil {
-		ctxt.Textp = nil
-		ctxt.Etextp = nil
-	} else {
-		last.Next = nil
-		ctxt.Etextp = last
 	}
+	ctxt.Textp = textp
 }
 
 var markextra = []string{

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

@@ -1432,7 +1432,7 @@ func writelines(prev *LSym) *LSym {
 
 	lang := DW_LANG_Go
 
-	s := Ctxt.Textp
+	s := Ctxt.Textp[0]
 
 	dwinfo = newdie(&dwroot, DW_ABRV_COMPUNIT, "go", 0)
 	newattr(dwinfo, DW_AT_language, DW_CLS_CONSTANT, int64(lang), 0)
@@ -1502,8 +1502,8 @@ func writelines(prev *LSym) *LSym {
 
 	var pcfile Pciter
 	var pcline Pciter
-	for Ctxt.Cursym = Ctxt.Textp; Ctxt.Cursym != nil; Ctxt.Cursym = Ctxt.Cursym.Next {
-		s = Ctxt.Cursym
+	for _, Ctxt.Cursym = range Ctxt.Textp {
+		s := Ctxt.Cursym
 
 		dwfunc := newdie(dwinfo, DW_ABRV_FUNCTION, s.Name, int(s.Version))
 		newattr(dwfunc, DW_AT_low_pc, DW_CLS_ADDRESS, s.Value, s)
@@ -1696,7 +1696,7 @@ func writeframes(prev *LSym) *LSym {
 
 	var deltaBuf []byte
 	var pcsp Pciter
-	for Ctxt.Cursym = Ctxt.Textp; Ctxt.Cursym != nil; Ctxt.Cursym = Ctxt.Cursym.Next {
+	for _, Ctxt.Cursym = range Ctxt.Textp {
 		s := Ctxt.Cursym
 		if s.FuncInfo == nil {
 			continue

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

@@ -1727,7 +1727,7 @@ func Elfemitreloc() {
 		Cput(0)
 	}
 
-	elfrelocsect(Segtext.Sect, list2slice(Ctxt.Textp))
+	elfrelocsect(Segtext.Sect, Ctxt.Textp)
 	for sect := Segtext.Sect.Next; sect != nil; sect = sect.Next {
 		elfrelocsect(sect, datap)
 	}

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

@@ -842,19 +842,13 @@ func ldelf(f *bio.Reader, pkg string, length int64, pn string) {
 				log.Fatalf("symbol %s listed multiple times", s.Name)
 			}
 			s.Attr |= AttrOnList
-			if Ctxt.Etextp != nil {
-				Ctxt.Etextp.Next = s
-			} else {
-				Ctxt.Textp = s
-			}
-			Ctxt.Etextp = s
+			Ctxt.Textp = append(Ctxt.Textp, s)
 			for s = s.Sub; s != nil; s = s.Sub {
 				if s.Attr.OnList() {
 					log.Fatalf("symbol %s listed multiple times", s.Name)
 				}
 				s.Attr |= AttrOnList
-				Ctxt.Etextp.Next = s
-				Ctxt.Etextp = s
+				Ctxt.Textp = append(Ctxt.Textp, s)
 			}
 		}
 	}

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

@@ -707,19 +707,13 @@ func ldmacho(f *bio.Reader, pkg string, length int64, pn string) {
 				log.Fatalf("symbol %s listed multiple times", s.Name)
 			}
 			s.Attr |= AttrOnList
-			if Ctxt.Etextp != nil {
-				Ctxt.Etextp.Next = s
-			} else {
-				Ctxt.Textp = s
-			}
-			Ctxt.Etextp = s
+			Ctxt.Textp = append(Ctxt.Textp, s)
 			for s1 = s.Sub; s1 != nil; s1 = s1.Sub {
 				if s1.Attr.OnList() {
 					log.Fatalf("symbol %s listed multiple times", s1.Name)
 				}
 				s1.Attr |= AttrOnList
-				Ctxt.Etextp.Next = s1
-				Ctxt.Etextp = s1
+				Ctxt.Textp = append(Ctxt.Textp, s1)
 			}
 		}
 	}

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

@@ -435,19 +435,13 @@ func ldpe(f *bio.Reader, pkg string, length int64, pn string) {
 				log.Fatalf("symbol %s listed multiple times", s.Name)
 			}
 			s.Attr |= AttrOnList
-			if Ctxt.Etextp != nil {
-				Ctxt.Etextp.Next = s
-			} else {
-				Ctxt.Textp = s
-			}
-			Ctxt.Etextp = s
+			Ctxt.Textp = append(Ctxt.Textp, s)
 			for s = s.Sub; s != nil; s = s.Sub {
 				if s.Attr.OnList() {
 					log.Fatalf("symbol %s listed multiple times", s.Name)
 				}
 				s.Attr |= AttrOnList
-				Ctxt.Etextp.Next = s
-				Ctxt.Etextp = s
+				Ctxt.Textp = append(Ctxt.Textp, s)
 			}
 		}
 	}

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

@@ -1545,30 +1545,14 @@ func ldshlibsyms(shlib string) {
 
 	// We might have overwritten some functions above (this tends to happen for the
 	// autogenerated type equality/hashing functions) and we don't want to generated
-	// pcln table entries for these any more so unstitch them from the Textp linked
-	// list.
-	var last *LSym
-
-	for s := Ctxt.Textp; s != nil; s = s.Next {
-		if s.Type == obj.SDYNIMPORT {
-			continue
-		}
-
-		if last == nil {
-			Ctxt.Textp = s
-		} else {
-			last.Next = s
+	// pcln table entries for these any more so remove them from Textp.
+	textp := make([]*LSym, 0, len(Ctxt.Textp))
+	for _, s := range Ctxt.Textp {
+		if s.Type != obj.SDYNIMPORT {
+			textp = append(textp, s)
 		}
-		last = s
-	}
-
-	if last == nil {
-		Ctxt.Textp = nil
-		Ctxt.Etextp = nil
-	} else {
-		last.Next = nil
-		Ctxt.Etextp = last
 	}
+	Ctxt.Textp = textp
 
 	Ctxt.Shlibs = append(Ctxt.Shlibs, Shlib{Path: libpath, Hash: hash, Deps: deps, File: f, gcdata_addresses: gcdata_addresses})
 }
@@ -1682,7 +1666,7 @@ func dostkcheck() {
 
 	// Check every function, but do the nosplit functions in a first pass,
 	// to make the printed failure chains as short as possible.
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for _, s := range Ctxt.Textp {
 		// runtime.racesymbolizethunk is called from gcc-compiled C
 		// code running on the operating system thread stack.
 		// It uses more than the usual amount of stack but that's okay.
@@ -1697,7 +1681,7 @@ func dostkcheck() {
 		}
 	}
 
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for _, s := range Ctxt.Textp {
 		if !s.Attr.NoSplit() {
 			Ctxt.Cursym = s
 			ch.sym = s
@@ -1995,7 +1979,7 @@ func genasmsym(put func(*LSym, string, int, int64, int64, int, *LSym)) {
 	}
 
 	var off int32
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for _, s := range Ctxt.Textp {
 		put(s, s.Name, 'T', s.Value, s.Size, int(s.Version), s.Gotype)
 
 		locals := int32(0)
@@ -2105,7 +2089,7 @@ func undefsym(s *LSym) {
 }
 
 func undef() {
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for _, s := range Ctxt.Textp {
 		undefsym(s)
 	}
 	for _, s := range datap {
@@ -2123,7 +2107,7 @@ func callgraph() {
 
 	var i int
 	var r *Reloc
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for _, s := range Ctxt.Textp {
 		for i = 0; i < len(s.R); i++ {
 			r = &s.R[i]
 			if r.Sym == nil {

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

@@ -178,8 +178,7 @@ type Link struct {
 	Diag       func(string, ...interface{})
 	Cursym     *LSym
 	Version    int
-	Textp      *LSym
-	Etextp     *LSym
+	Textp      []*LSym
 	Nhistfile  int32
 	Filesyms   *LSym
 	Moduledata *LSym

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

@@ -852,7 +852,7 @@ func Machoemitreloc() {
 		Cput(0)
 	}
 
-	machorelocsect(Segtext.Sect, list2slice(Ctxt.Textp))
+	machorelocsect(Segtext.Sect, Ctxt.Textp)
 	for sect := Segtext.Sect.Next; sect != nil; sect = sect.Next {
 		machorelocsect(sect, datap)
 	}

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

@@ -398,12 +398,7 @@ overwrite:
 				log.Fatalf("symbol %s listed multiple times", s.Name)
 			}
 			s.Attr |= AttrOnList
-			if r.ctxt.Etextp != nil {
-				r.ctxt.Etextp.Next = s
-			} else {
-				r.ctxt.Textp = s
-			}
-			r.ctxt.Etextp = s
+			r.ctxt.Textp = append(r.ctxt.Textp, s)
 		}
 	}
 }

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

@@ -224,14 +224,14 @@ func pclntab() {
 	nfunc := int32(0)
 
 	// Find container symbols, mark them with SCONTAINER
-	for Ctxt.Cursym = Ctxt.Textp; Ctxt.Cursym != nil; Ctxt.Cursym = Ctxt.Cursym.Next {
-		if Ctxt.Cursym.Outer != nil {
-			Ctxt.Cursym.Outer.Type |= obj.SCONTAINER
+	for _, s := range Ctxt.Textp {
+		if s.Outer != nil {
+			s.Outer.Type |= obj.SCONTAINER
 		}
 	}
 
-	for Ctxt.Cursym = Ctxt.Textp; Ctxt.Cursym != nil; Ctxt.Cursym = Ctxt.Cursym.Next {
-		if container(Ctxt.Cursym) == 0 {
+	for _, s := range Ctxt.Textp {
+		if container(s) == 0 {
 			nfunc++
 		}
 	}
@@ -246,7 +246,7 @@ func pclntab() {
 
 	nfunc = 0
 	var last *LSym
-	for Ctxt.Cursym = Ctxt.Textp; Ctxt.Cursym != nil; Ctxt.Cursym = Ctxt.Cursym.Next {
+	for _, Ctxt.Cursym = range Ctxt.Textp {
 		last = Ctxt.Cursym
 		if container(Ctxt.Cursym) != 0 {
 			continue
@@ -401,10 +401,9 @@ func findfunctab() {
 	t.Attr |= AttrLocal
 
 	// find min and max address
-	min := Ctxt.Textp.Value
-
+	min := Ctxt.Textp[0].Value
 	max := int64(0)
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for _, s := range Ctxt.Textp {
 		max = s.Value + s.Size
 	}
 
@@ -417,34 +416,34 @@ func findfunctab() {
 		indexes[i] = NOIDX
 	}
 	idx := int32(0)
-	var e *LSym
-	var i int32
-	var p int64
-	var q int64
-	for s := Ctxt.Textp; s != nil; s = s.Next {
+	for i, s := range Ctxt.Textp {
 		if container(s) != 0 {
 			continue
 		}
-		p = s.Value
-		e = s.Next
-		for container(e) != 0 {
-			e = e.Next
+		p := s.Value
+		var e *LSym
+		i++
+		if i < len(Ctxt.Textp) {
+			e = Ctxt.Textp[i]
+		}
+		for container(e) != 0 && i < len(Ctxt.Textp) {
+			e = Ctxt.Textp[i]
+			i++
 		}
+		q := max
 		if e != nil {
 			q = e.Value
-		} else {
-			q = max
 		}
 
 		//print("%d: [%lld %lld] %s\n", idx, p, q, s->name);
 		for ; p < q; p += SUBBUCKETSIZE {
-			i = int32((p - min) / SUBBUCKETSIZE)
+			i = int((p - min) / SUBBUCKETSIZE)
 			if indexes[i] > idx {
 				indexes[i] = idx
 			}
 		}
 
-		i = int32((q - 1 - min) / SUBBUCKETSIZE)
+		i = int((q - 1 - min) / SUBBUCKETSIZE)
 		if indexes[i] > idx {
 			indexes[i] = idx
 		}
@@ -457,15 +456,13 @@ func findfunctab() {
 	Symgrow(Ctxt, t, 4*int64(nbuckets)+int64(n))
 
 	// fill in table
-	var base int32
-	var j int32
 	for i := int32(0); i < nbuckets; i++ {
-		base = indexes[i*SUBBUCKETS]
+		base := indexes[i*SUBBUCKETS]
 		if base == NOIDX {
 			Diag("hole in findfunctab")
 		}
 		setuint32(Ctxt, t, int64(i)*(4+SUBBUCKETS), uint32(base))
-		for j = 0; j < SUBBUCKETS && i*SUBBUCKETS+j < n; j++ {
+		for j := int32(0); j < SUBBUCKETS && i*SUBBUCKETS+j < n; j++ {
 			idx = indexes[i*SUBBUCKETS+j]
 			if idx == NOIDX {
 				Diag("hole in findfunctab")

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

@@ -831,7 +831,7 @@ func peemitreloc(text, data, ctors *IMAGE_SECTION_HEADER) {
 	Lputl(0)
 	Wputl(0)
 
-	n := perelocsect(Segtext.Sect, list2slice(Ctxt.Textp)) + 1
+	n := perelocsect(Segtext.Sect, Ctxt.Textp) + 1
 	for sect := Segtext.Sect.Next; sect != nil; sect = sect.Next {
 		n += perelocsect(sect, datap)
 	}

src/cmd/link/internal/ppc64/asm.go

@@ -87,9 +87,7 @@ func genplt() {
 	//
 	// This assumes "case 1" from the ABI, where the caller needs
 	// us to save and restore the TOC pointer.
-	pprevtextp := &ld.Ctxt.Textp
-
-	for s := *pprevtextp; s != nil; pprevtextp, s = &s.Next, s.Next {
+	for _, s := range ld.Ctxt.Textp {
 		for i := range s.R {
 			r := &s.R[i]
 			if r.Type != 256+ld.R_PPC64_REL24 || r.Sym.Type != obj.SDYNIMPORT {
@@ -110,15 +108,7 @@ func genplt() {
 			if stub.Size == 0 {
 				// Need outer to resolve .TOC.
 				stub.Outer = s
-
-				// Link in to textp before s (we could
-				// do it after, but would have to skip
-				// the subsymbols)
-				*pprevtextp = stub
-
-				stub.Next = s
-				pprevtextp = &stub.Next
-
+				ld.Ctxt.Textp = append(ld.Ctxt.Textp, stub)
 				gencallstub(1, stub, r.Sym)
 			}
 
@@ -131,7 +121,6 @@ func genplt() {
 			ld.Ctxt.Arch.ByteOrder.PutUint32(s.P[r.Off+4:], o1)
 		}
 	}
-
 }
 
 func genaddmoduledata() {
@@ -187,13 +176,7 @@ func genaddmoduledata() {
 	// blr
 	o(0x4e800020)
 
-	if ld.Ctxt.Etextp != nil {
-		ld.Ctxt.Etextp.Next = initfunc
-	} else {
-		ld.Ctxt.Textp = initfunc
-	}
-	ld.Ctxt.Etextp = initfunc
-
+	ld.Ctxt.Textp = append(ld.Ctxt.Textp, initfunc)
 	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
 	initarray_entry.Attr |= ld.AttrReachable
 	initarray_entry.Attr |= ld.AttrLocal

src/cmd/link/internal/s390x/asm.go

@@ -90,12 +90,7 @@ func gentext() {
 	// undef (for debugging)
 	ld.Adduint32(ld.Ctxt, initfunc, 0)
 
-	if ld.Ctxt.Etextp != nil {
-		ld.Ctxt.Etextp.Next = initfunc
-	} else {
-		ld.Ctxt.Textp = initfunc
-	}
-	ld.Ctxt.Etextp = initfunc
+	ld.Ctxt.Textp = append(ld.Ctxt.Textp, initfunc)
 	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
 	initarray_entry.Attr |= ld.AttrLocal
 	initarray_entry.Attr |= ld.AttrReachable

src/cmd/link/internal/x86/asm.go

@@ -69,12 +69,7 @@ func gentext() {
 	// c3		ret
 	o(0xc3)
 
-	if ld.Ctxt.Etextp != nil {
-		ld.Ctxt.Etextp.Next = thunkfunc
-	} else {
-		ld.Ctxt.Textp = thunkfunc
-	}
-	ld.Ctxt.Etextp = thunkfunc
+	ld.Ctxt.Textp = append(ld.Ctxt.Textp, thunkfunc)
 
 	addmoduledata := ld.Linklookup(ld.Ctxt, "runtime.addmoduledata", 0)
 	if addmoduledata.Type == obj.STEXT {
@@ -130,8 +125,7 @@ func gentext() {
 
 	o(0xc3)
 
-	ld.Ctxt.Etextp.Next = initfunc
-	ld.Ctxt.Etextp = initfunc
+	ld.Ctxt.Textp = append(ld.Ctxt.Textp, initfunc)
 	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
 	initarray_entry.Attr |= ld.AttrReachable
 	initarray_entry.Attr |= ld.AttrLocal