all: use ":" for compiler generated symbols

As it can't appear in user package paths.

There is a hack for handling "go:buildid" and "type:*" on windows/386.

Previously, windows/386 requires underscore prefix on external symbols,
but that's only applied for SHOSTOBJ/SUNDEFEXT or cgo export symbols.
"go.buildid" is STEXT, "type.*" is STYPE, thus they are not prefixed
with underscore.

In external linking mode, the external linker can't resolve them as
external symbols. But we are lucky that they have "." in their name,
so the external linker see them as Forwarder RVA exports. See:

 - https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#export-address-table
 - https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/pe-dll.c;h=e7b82ba6ffadf74dc1b9ee71dc13d48336941e51;hb=HEAD#l972)

This CL changes "." to ":" in symbols name, so theses symbols can not be
found by external linker anymore. So a hacky way is adding the
underscore prefix for these 2 symbols. I don't have enough knowledge to
verify whether adding the underscore for all STEXT/STYPE symbols are
fine, even if it could be, that would be done in future CL.

Fixes #37762

Change-Id: I92eaaf24c0820926a36e0530fdb07b07af1fcc35
Reviewed-on: https://go-review.googlesource.com/c/go/+/317917
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

misc/cgo/testshared/shared_test.go

@@ -589,12 +589,12 @@ func testABIHashNote(t *testing.T, f *elf.File, note *note) {
 		return
 	}
 	for _, sym := range symbols {
-		if sym.Name == "go.link.abihashbytes" {
+		if sym.Name == "go:link.abihashbytes" {
 			hashbytes = sym
 		}
 	}
 	if hashbytes.Name == "" {
-		t.Errorf("no symbol called go.link.abihashbytes")
+		t.Errorf("no symbol called go:link.abihashbytes")
 		return
 	}
 	if elf.ST_BIND(hashbytes.Info) != elf.STB_LOCAL {

src/cmd/compile/internal/base/link.go

@@ -8,6 +8,19 @@ import (
 	"cmd/internal/obj"
 )
 
+// ReservedImports are import paths used internally for generated
+// symbols by the compiler.
+//
+// The linker uses the magic symbol prefixes "go:" and "type:".
+// Avoid potential confusion between import paths and symbols
+// by rejecting these reserved imports for now. Also, people
+// "can do weird things in GOPATH and we'd prefer they didn't
+// do _that_ weird thing" (per rsc). See also #4257.
+var ReservedImports = map[string]bool{
+	"go":   true,
+	"type": true,
+}
+
 var Ctxt *obj.Link
 
 // TODO(mdempsky): These should probably be obj.Link methods.
@@ -20,7 +33,11 @@ func PkgLinksym(prefix, name string, abi obj.ABI) *obj.LSym {
 		// TODO(mdempsky): Cleanup callers and Fatalf instead.
 		return linksym(prefix, "_", abi)
 	}
-	return linksym(prefix, prefix+"."+name, abi)
+	sep := "."
+	if ReservedImports[prefix] {
+		sep = ":"
+	}
+	return linksym(prefix, prefix+sep+name, abi)
 }
 
 // Linkname returns the linker symbol for the given name as it might

src/cmd/compile/internal/dwarfgen/dwarf.go

@@ -471,7 +471,7 @@ func createComplexVar(fnsym *obj.LSym, fn *ir.Func, varID ssa.VarID) *dwarf.Var
 
 	gotype := reflectdata.TypeLinksym(n.Type())
 	delete(fnsym.Func().Autot, gotype)
-	typename := dwarf.InfoPrefix + gotype.Name[len("type."):]
+	typename := dwarf.InfoPrefix + gotype.Name[len("type:"):]
 	inlIndex := 0
 	if base.Flag.GenDwarfInl > 1 {
 		if n.InlFormal() || n.InlLocal() {

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

@@ -77,7 +77,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 
 	// pseudo-package, for scoping
 	types.BuiltinPkg = types.NewPkg("go.builtin", "") // TODO(gri) name this package go.builtin?
-	types.BuiltinPkg.Prefix = "go.builtin"            // not go%2ebuiltin
+	types.BuiltinPkg.Prefix = "go:builtin"
 
 	// pseudo-package, accessed by import "unsafe"
 	types.UnsafePkg = types.NewPkg("unsafe", "unsafe")
@@ -92,7 +92,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 
 	// pseudo-packages used in symbol tables
 	ir.Pkgs.Itab = types.NewPkg("go.itab", "go.itab")
-	ir.Pkgs.Itab.Prefix = "go.itab" // not go%2eitab
+	ir.Pkgs.Itab.Prefix = "go:itab"
 
 	// pseudo-package used for methods with anonymous receivers
 	ir.Pkgs.Go = types.NewPkg("go", "")

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

@@ -148,7 +148,7 @@ func dumpdata() {
 	dumpglobls(typecheck.Target.Externs[numExterns:])
 
 	if reflectdata.ZeroSize > 0 {
-		zero := base.PkgLinksym("go.map", "zero", obj.ABI0)
+		zero := base.PkgLinksym("go:map", "zero", obj.ABI0)
 		objw.Global(zero, int32(reflectdata.ZeroSize), obj.DUPOK|obj.RODATA)
 		zero.Set(obj.AttrStatic, true)
 	}

src/cmd/compile/internal/ir/expr.go

@@ -1134,7 +1134,6 @@ func MethodSymSuffix(recv *types.Type, msym *types.Sym, suffix string) *types.Sy
 	b.WriteString(".")
 	b.WriteString(msym.Name)
 	b.WriteString(suffix)
-
 	return rpkg.LookupBytes(b.Bytes())
 }
 

src/cmd/compile/internal/noder/import.go

@@ -355,16 +355,6 @@ func addFingerprint(path string, f *os.File, end int64) error {
 	return nil
 }
 
-// The linker uses the magic symbol prefixes "go." and "type."
-// Avoid potential confusion between import paths and symbols
-// by rejecting these reserved imports for now. Also, people
-// "can do weird things in GOPATH and we'd prefer they didn't
-// do _that_ weird thing" (per rsc). See also #4257.
-var reservedimports = []string{
-	"go",
-	"type",
-}
-
 func checkImportPath(path string, allowSpace bool) error {
 	if path == "" {
 		return errors.New("import path is empty")
@@ -374,7 +364,7 @@ func checkImportPath(path string, allowSpace bool) error {
 		return errors.New("import path contains NUL")
 	}
 
-	for _, ri := range reservedimports {
+	for ri := range base.ReservedImports {
 		if path == ri {
 			return fmt.Errorf("import path %q is reserved and cannot be used", path)
 		}

src/cmd/compile/internal/ppc64/ssa.go

@@ -853,7 +853,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 			// Special case for a rule combines the bytes of gostring.
 			// The v alignment might seem OK, but we don't want to load it
 			// using an offset because relocation comes later.
-			genAddr = strings.HasPrefix(fromAddr.Sym.Name, "go.string") || v.Type.Alignment()%4 != 0 || fromAddr.Offset%4 != 0
+			genAddr = strings.HasPrefix(fromAddr.Sym.Name, "go:string") || v.Type.Alignment()%4 != 0 || fromAddr.Offset%4 != 0
 		default:
 			genAddr = fromAddr.Offset%4 != 0
 		}

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

@@ -411,7 +411,7 @@ func dimportpath(p *types.Pkg) {
 		return
 	}
 
-	s := base.Ctxt.Lookup("type..importpath." + p.Prefix + ".")
+	s := base.Ctxt.Lookup("type:.importpath." + p.Prefix + ".")
 	ot := dnameData(s, 0, p.Path, "", nil, false, false)
 	objw.Global(s, int32(ot), obj.DUPOK|obj.RODATA)
 	s.Set(obj.AttrContentAddressable, true)
@@ -426,10 +426,10 @@ func dgopkgpath(s *obj.LSym, ot int, pkg *types.Pkg) int {
 	if pkg == types.LocalPkg && base.Ctxt.Pkgpath == "" {
 		// If we don't know the full import path of the package being compiled
 		// (i.e. -p was not passed on the compiler command line), emit a reference to
-		// type..importpath.""., which the linker will rewrite using the correct import path.
+		// 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 := base.Ctxt.Lookup(`type..importpath."".`)
+		ns := base.Ctxt.Lookup(`type:.importpath."".`)
 		return objw.SymPtr(s, ot, ns, 0)
 	}
 
@@ -445,10 +445,10 @@ func dgopkgpathOff(s *obj.LSym, ot int, pkg *types.Pkg) int {
 	if pkg == types.LocalPkg && base.Ctxt.Pkgpath == "" {
 		// If we don't know the full import path of the package being compiled
 		// (i.e. -p was not passed on the compiler command line), emit a reference to
-		// type..importpath.""., which the linker will rewrite using the correct import path.
+		// 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 := base.Ctxt.Lookup(`type..importpath."".`)
+		ns := base.Ctxt.Lookup(`type:.importpath."".`)
 		return objw.SymPtrOff(s, ot, ns)
 	}
 
@@ -517,11 +517,11 @@ var dnameCount int
 
 // dname creates a reflect.name for a struct field or method.
 func dname(name, tag string, pkg *types.Pkg, exported, embedded bool) *obj.LSym {
-	// Write out data as "type.." to signal two things to the
+	// Write out data as "type:." to signal two things to the
 	// linker, first that when dynamically linking, the symbol
 	// should be moved to a relro section, and second that the
 	// contents should not be decoded as a type.
-	sname := "type..namedata."
+	sname := "type:.namedata."
 	if pkg == nil {
 		// In the common case, share data with other packages.
 		if name == "" {
@@ -798,7 +798,7 @@ func dcommontype(lsym *obj.LSym, t *types.Type) int {
 // TrackSym returns the symbol for tracking use of field/method f, assumed
 // to be a member of struct/interface type t.
 func TrackSym(t *types.Type, f *types.Field) *obj.LSym {
-	return base.PkgLinksym("go.track", t.LinkString()+"."+f.Sym.Name, obj.ABI0)
+	return base.PkgLinksym("go:track", t.LinkString()+"."+f.Sym.Name, obj.ABI0)
 }
 
 func TypeSymPrefix(prefix string, t *types.Type) *types.Sym {
@@ -1358,7 +1358,7 @@ func WriteTabs() {
 	// process ptabs
 	if types.LocalPkg.Name == "main" && len(ptabs) > 0 {
 		ot := 0
-		s := base.Ctxt.Lookup("go.plugin.tabs")
+		s := base.Ctxt.Lookup("go:plugin.tabs")
 		for _, p := range ptabs {
 			// Dump ptab symbol into go.pluginsym package.
 			//
@@ -1381,7 +1381,7 @@ func WriteTabs() {
 		objw.Global(s, int32(ot), int16(obj.RODATA))
 
 		ot = 0
-		s = base.Ctxt.Lookup("go.plugin.exports")
+		s = base.Ctxt.Lookup("go:plugin.exports")
 		for _, p := range ptabs {
 			ot = objw.SymPtr(s, ot, p.Linksym(), 0)
 		}
@@ -1715,7 +1715,7 @@ func ZeroAddr(size int64) ir.Node {
 	if ZeroSize < size {
 		ZeroSize = size
 	}
-	lsym := base.PkgLinksym("go.map", "zero", obj.ABI0)
+	lsym := base.PkgLinksym("go:map", "zero", obj.ABI0)
 	x := ir.NewLinksymExpr(base.Pos, lsym, types.Types[types.TUINT8])
 	return typecheck.Expr(typecheck.NodAddr(x))
 }

src/cmd/compile/internal/staticdata/data.go

@@ -61,7 +61,7 @@ func InitSliceBytes(nam *ir.Name, off int64, s string) {
 }
 
 const (
-	stringSymPrefix  = "go.string."
+	stringSymPrefix  = "go:string."
 	stringSymPattern = ".gostring.%d.%s"
 )
 

src/cmd/internal/dwarf/dwarf.go

@@ -21,15 +21,15 @@ import (
 )
 
 // InfoPrefix is the prefix for all the symbols containing DWARF info entries.
-const InfoPrefix = "go.info."
+const InfoPrefix = "go:info."
 
 // ConstInfoPrefix is the prefix for all symbols containing DWARF info
 // entries that contain constants.
-const ConstInfoPrefix = "go.constinfo."
+const ConstInfoPrefix = "go:constinfo."
 
 // CUInfoPrefix is the prefix for symbols containing information to
 // populate the DWARF compilation unit info entries.
-const CUInfoPrefix = "go.cuinfo."
+const CUInfoPrefix = "go:cuinfo."
 
 // Used to form the symbol name assigned to the DWARF 'abstract subprogram"
 // info entry for a function

src/cmd/internal/goobj/builtinlist.go

@@ -214,40 +214,40 @@ var builtins = [...]struct {
 	{"runtime.morestack", 0},
 	{"runtime.morestackc", 0},
 	{"runtime.morestack_noctxt", 0},
-	{"type.int8", 0},
-	{"type.*int8", 0},
-	{"type.uint8", 0},
-	{"type.*uint8", 0},
-	{"type.int16", 0},
-	{"type.*int16", 0},
-	{"type.uint16", 0},
-	{"type.*uint16", 0},
-	{"type.int32", 0},
-	{"type.*int32", 0},
-	{"type.uint32", 0},
-	{"type.*uint32", 0},
-	{"type.int64", 0},
-	{"type.*int64", 0},
-	{"type.uint64", 0},
-	{"type.*uint64", 0},
-	{"type.float32", 0},
-	{"type.*float32", 0},
-	{"type.float64", 0},
-	{"type.*float64", 0},
-	{"type.complex64", 0},
-	{"type.*complex64", 0},
-	{"type.complex128", 0},
-	{"type.*complex128", 0},
-	{"type.unsafe.Pointer", 0},
-	{"type.*unsafe.Pointer", 0},
-	{"type.uintptr", 0},
-	{"type.*uintptr", 0},
-	{"type.bool", 0},
-	{"type.*bool", 0},
-	{"type.string", 0},
-	{"type.*string", 0},
-	{"type.error", 0},
-	{"type.*error", 0},
-	{"type.func(error) string", 0},
-	{"type.*func(error) string", 0},
+	{"type:int8", 0},
+	{"type:*int8", 0},
+	{"type:uint8", 0},
+	{"type:*uint8", 0},
+	{"type:int16", 0},
+	{"type:*int16", 0},
+	{"type:uint16", 0},
+	{"type:*uint16", 0},
+	{"type:int32", 0},
+	{"type:*int32", 0},
+	{"type:uint32", 0},
+	{"type:*uint32", 0},
+	{"type:int64", 0},
+	{"type:*int64", 0},
+	{"type:uint64", 0},
+	{"type:*uint64", 0},
+	{"type:float32", 0},
+	{"type:*float32", 0},
+	{"type:float64", 0},
+	{"type:*float64", 0},
+	{"type:complex64", 0},
+	{"type:*complex64", 0},
+	{"type:complex128", 0},
+	{"type:*complex128", 0},
+	{"type:unsafe.Pointer", 0},
+	{"type:*unsafe.Pointer", 0},
+	{"type:uintptr", 0},
+	{"type:*uintptr", 0},
+	{"type:bool", 0},
+	{"type:*bool", 0},
+	{"type:string", 0},
+	{"type:*string", 0},
+	{"type:error", 0},
+	{"type:*error", 0},
+	{"type:func(error) string", 0},
+	{"type:*func(error) string", 0},
 }

src/cmd/internal/goobj/mkbuiltin.go

@@ -105,7 +105,7 @@ func mkbuiltin(w io.Writer) {
 	extras := append(fextras[:], enumerateBasicTypes()...)
 	for _, b := range extras {
 		prefix := ""
-		if !strings.HasPrefix(b.name, "type.") {
+		if !strings.HasPrefix(b.name, "type:") {
 			prefix = pkg + "."
 		}
 		name := prefix + b.name
@@ -130,8 +130,8 @@ func enumerateBasicTypes() []extra {
 		"func(error) string"}
 	result := []extra{}
 	for _, n := range names {
-		result = append(result, extra{"type." + n, 0})
-		result = append(result, extra{"type.*" + n, 0})
+		result = append(result, extra{"type:" + n, 0})
+		result = append(result, extra{"type:*" + n, 0})
 	}
 	return result
 }

src/cmd/internal/obj/objfile.go

@@ -321,14 +321,14 @@ func (w *writer) Sym(s *LSym) {
 	if s.ReflectMethod() {
 		flag |= goobj.SymFlagReflectMethod
 	}
-	if strings.HasPrefix(s.Name, "type.") && s.Name[5] != '.' && s.Type == objabi.SRODATA {
+	if strings.HasPrefix(s.Name, "type:") && s.Name[5] != '.' && s.Type == objabi.SRODATA {
 		flag |= goobj.SymFlagGoType
 	}
 	flag2 := uint8(0)
 	if s.UsedInIface() {
 		flag2 |= goobj.SymFlagUsedInIface
 	}
-	if strings.HasPrefix(s.Name, "go.itab.") && s.Type == objabi.SRODATA {
+	if strings.HasPrefix(s.Name, "go:itab.") && s.Type == objabi.SRODATA {
 		flag2 |= goobj.SymFlagItab
 	}
 	if strings.HasPrefix(s.Name, w.ctxt.Pkgpath) && strings.HasPrefix(s.Name[len(w.ctxt.Pkgpath):], ".") && strings.HasPrefix(s.Name[len(w.ctxt.Pkgpath)+1:], objabi.GlobalDictPrefix) {
@@ -351,9 +351,9 @@ func (w *writer) Sym(s *LSym) {
 		// TODO: maybe the compiler could set the alignment for all
 		// data symbols more carefully.
 		switch {
-		case strings.HasPrefix(s.Name, "go.string."),
-			strings.HasPrefix(name, "type..namedata."),
-			strings.HasPrefix(name, "type..importpath."),
+		case strings.HasPrefix(s.Name, "go:string."),
+			strings.HasPrefix(name, "type:.namedata."),
+			strings.HasPrefix(name, "type:.importpath."),
 			strings.HasPrefix(name, "runtime.gcbits."),
 			strings.HasSuffix(name, ".opendefer"),
 			strings.HasSuffix(name, ".arginfo0"),
@@ -430,9 +430,9 @@ func contentHashSection(s *LSym) byte {
 		strings.HasSuffix(name, ".wrapinfo") ||
 		strings.HasSuffix(name, ".args_stackmap") ||
 		strings.HasSuffix(name, ".stkobj") {
-		return 'F' // go.func.* or go.funcrel.*
+		return 'F' // go:func.* or go:funcrel.*
 	}
-	if strings.HasPrefix(name, "type.") {
+	if strings.HasPrefix(name, "type:") {
 		return 'T'
 	}
 	return 0

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

@@ -222,7 +222,7 @@ func (st *relocSymState) relocsym(s loader.Sym, P []byte) {
 				if ldr.SymName(rs) == "main.main" || (!target.IsPlugin() && ldr.SymName(rs) == "main..inittask") {
 					sb := ldr.MakeSymbolUpdater(rs)
 					sb.SetType(sym.SDYNIMPORT)
-				} else if strings.HasPrefix(ldr.SymName(rs), "go.info.") {
+				} else if strings.HasPrefix(ldr.SymName(rs), "go:info.") {
 					// Skip go.info symbols. They are only needed to communicate
 					// DWARF info between the compiler and linker.
 					continue
@@ -1108,7 +1108,7 @@ func addstrdata(arch *sys.Arch, l *loader.Loader, name, value string) {
 	}
 	if goType := l.SymGoType(s); goType == 0 {
 		return
-	} else if typeName := l.SymName(goType); typeName != "type.string" {
+	} else if typeName := l.SymName(goType); typeName != "type:string" {
 		Errorf(nil, "%s: cannot set with -X: not a var of type string (%s)", name, typeName)
 		return
 	}
@@ -2152,7 +2152,7 @@ func (ctxt *Link) textbuildid() {
 	}
 
 	ldr := ctxt.loader
-	s := ldr.CreateSymForUpdate("go.buildid", 0)
+	s := ldr.CreateSymForUpdate("go:buildid", 0)
 	// The \xff is invalid UTF-8, meant to make it less likely
 	// to find one of these accidentally.
 	data := "\xff Go build ID: " + strconv.Quote(*flagBuildid) + "\n \xff"
@@ -2627,7 +2627,7 @@ func (ctxt *Link) address() []*sym.Segment {
 	}
 
 	if ctxt.BuildMode == BuildModeShared {
-		s := ldr.LookupOrCreateSym("go.link.abihashbytes", 0)
+		s := ldr.LookupOrCreateSym("go:link.abihashbytes", 0)
 		sect := ldr.SymSect(ldr.LookupOrCreateSym(".note.go.abihash", 0))
 		ldr.SetSymSect(s, sect)
 		ldr.SetSymValue(s, int64(sect.Vaddr+16))

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

@@ -72,11 +72,11 @@ func (d *deadcodePass) init() {
 	// We redirect unreachable methods to it.
 	names = append(names, "runtime.unreachableMethod")
 	if d.ctxt.BuildMode == BuildModePlugin {
-		names = append(names, objabi.PathToPrefix(*flagPluginPath)+"..inittask", objabi.PathToPrefix(*flagPluginPath)+".main", "go.plugin.tabs")
+		names = append(names, objabi.PathToPrefix(*flagPluginPath)+"..inittask", objabi.PathToPrefix(*flagPluginPath)+".main", "go:plugin.tabs")
 
 		// We don't keep the go.plugin.exports symbol,
 		// but we do keep the symbols it refers to.
-		exportsIdx := d.ldr.Lookup("go.plugin.exports", 0)
+		exportsIdx := d.ldr.Lookup("go:plugin.exports", 0)
 		if exportsIdx != 0 {
 			relocs := d.ldr.Relocs(exportsIdx)
 			for i := 0; i < relocs.Count(); i++ {

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

@@ -23,7 +23,7 @@ func TestDeadcode(t *testing.T) {
 		pos, neg string // positive and negative patterns
 	}{
 		{"reflectcall", "", "main.T.M"},
-		{"typedesc", "", "type.main.T"},
+		{"typedesc", "", "type:main.T"},
 		{"ifacemethod", "", "main.T.M"},
 		{"ifacemethod2", "main.T.M", ""},
 		{"ifacemethod3", "main.S.M", ""},

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

@@ -43,18 +43,18 @@ type dwctxt struct {
 	arch     *sys.Arch
 
 	// This maps type name string (e.g. "uintptr") to loader symbol for
-	// the DWARF DIE for that type (e.g. "go.info.type.uintptr")
+	// the DWARF DIE for that type (e.g. "go:info.type.uintptr")
 	tmap map[string]loader.Sym
 
 	// This maps loader symbol for the DWARF DIE symbol generated for
-	// a type (e.g. "go.info.uintptr") to the type symbol itself
-	// ("type.uintptr").
+	// a type (e.g. "go:info.uintptr") to the type symbol itself
+	// ("type:uintptr").
 	// FIXME: try converting this map (and the next one) to a single
 	// array indexed by loader.Sym -- this may perform better.
 	rtmap map[loader.Sym]loader.Sym
 
-	// This maps Go type symbol (e.g. "type.XXX") to loader symbol for
-	// the typedef DIE for that type (e.g. "go.info.XXX..def")
+	// This maps Go type symbol (e.g. "type:XXX") to loader symbol for
+	// the typedef DIE for that type (e.g. "go:info.XXX..def")
 	tdmap map[loader.Sym]loader.Sym
 
 	// Cache these type symbols, so as to avoid repeatedly looking them up
@@ -337,8 +337,8 @@ func walktypedef(die *dwarf.DWDie) *dwarf.DWDie {
 func (d *dwctxt) walksymtypedef(symIdx loader.Sym) loader.Sym {
 
 	// We're being given the loader symbol for the type DIE, e.g.
-	// "go.info.type.uintptr". Map that first to the type symbol (e.g.
-	// "type.uintptr") and then to the typedef DIE for the type.
+	// "go:info.type.uintptr". Map that first to the type symbol (e.g.
+	// "type:uintptr") and then to the typedef DIE for the type.
 	// FIXME: this seems clunky, maybe there is a better way to do this.
 
 	if ts, ok := d.rtmap[symIdx]; ok {
@@ -519,8 +519,8 @@ func (d *dwctxt) defgotype(gotype loader.Sym) loader.Sym {
 	}
 
 	sn := d.ldr.SymName(gotype)
-	if !strings.HasPrefix(sn, "type.") {
-		d.linkctxt.Errorf(gotype, "dwarf: type name doesn't start with \"type.\"")
+	if !strings.HasPrefix(sn, "type:") {
+		d.linkctxt.Errorf(gotype, "dwarf: type name doesn't start with \"type:\"")
 		return d.mustFind("<unspecified>")
 	}
 	name := sn[5:] // could also decode from Type.string
@@ -678,7 +678,7 @@ func (d *dwctxt) newtype(gotype loader.Sym) *dwarf.DWDie {
 			s := decodetypeStructFieldType(d.ldr, d.arch, gotype, i)
 			if f == "" {
 				sn := d.ldr.SymName(s)
-				f = sn[5:] // skip "type."
+				f = sn[5:] // skip "type:"
 			}
 			fld := d.newdie(die, dwarf.DW_ABRV_STRUCTFIELD, f)
 			d.newrefattr(fld, dwarf.DW_AT_type, d.defgotype(s))
@@ -747,7 +747,7 @@ func (d *dwctxt) defptrto(dwtype loader.Sym) loader.Sym {
 	// The DWARF info synthesizes pointer types that don't exist at the
 	// language level, like *hash<...> and *bucket<...>, and the data
 	// pointers of slices. Link to the ones we can find.
-	gts := d.ldr.Lookup("type."+ptrname, 0)
+	gts := d.ldr.Lookup("type:"+ptrname, 0)
 	if gts != 0 && d.ldr.AttrReachable(gts) {
 		newattr(pdie, dwarf.DW_AT_go_runtime_type, dwarf.DW_CLS_GO_TYPEREF, 0, dwSym(gts))
 	}
@@ -814,7 +814,7 @@ func (d *dwctxt) findprotodie(ctxt *Link, name string) *dwarf.DWDie {
 }
 
 func (d *dwctxt) synthesizestringtypes(ctxt *Link, die *dwarf.DWDie) {
-	prototype := walktypedef(d.findprotodie(ctxt, "type.runtime.stringStructDWARF"))
+	prototype := walktypedef(d.findprotodie(ctxt, "type:runtime.stringStructDWARF"))
 	if prototype == nil {
 		return
 	}
@@ -828,7 +828,7 @@ func (d *dwctxt) synthesizestringtypes(ctxt *Link, die *dwarf.DWDie) {
 }
 
 func (d *dwctxt) synthesizeslicetypes(ctxt *Link, die *dwarf.DWDie) {
-	prototype := walktypedef(d.findprotodie(ctxt, "type.runtime.slice"))
+	prototype := walktypedef(d.findprotodie(ctxt, "type:runtime.slice"))
 	if prototype == nil {
 		return
 	}
@@ -870,8 +870,8 @@ func (d *dwctxt) mkinternaltype(ctxt *Link, abbrev int, typename, keyname, valna
 }
 
 func (d *dwctxt) synthesizemaptypes(ctxt *Link, die *dwarf.DWDie) {
-	hash := walktypedef(d.findprotodie(ctxt, "type.runtime.hmap"))
-	bucket := walktypedef(d.findprotodie(ctxt, "type.runtime.bmap"))
+	hash := walktypedef(d.findprotodie(ctxt, "type:runtime.hmap"))
+	bucket := walktypedef(d.findprotodie(ctxt, "type:runtime.bmap"))
 
 	if hash == nil {
 		return
@@ -966,9 +966,9 @@ func (d *dwctxt) synthesizemaptypes(ctxt *Link, die *dwarf.DWDie) {
 }
 
 func (d *dwctxt) synthesizechantypes(ctxt *Link, die *dwarf.DWDie) {
-	sudog := walktypedef(d.findprotodie(ctxt, "type.runtime.sudog"))
-	waitq := walktypedef(d.findprotodie(ctxt, "type.runtime.waitq"))
-	hchan := walktypedef(d.findprotodie(ctxt, "type.runtime.hchan"))
+	sudog := walktypedef(d.findprotodie(ctxt, "type:runtime.sudog"))
+	waitq := walktypedef(d.findprotodie(ctxt, "type:runtime.waitq"))
+	hchan := walktypedef(d.findprotodie(ctxt, "type:runtime.hchan"))
 	if sudog == nil || waitq == nil || hchan == nil {
 		return
 	}
@@ -1135,7 +1135,7 @@ func (d *dwctxt) importInfoSymbol(dsym loader.Sym) {
 		// symbol name here?
 		sn := d.ldr.SymName(rsym)
 		tn := sn[len(dwarf.InfoPrefix):]
-		ts := d.ldr.Lookup("type."+tn, 0)
+		ts := d.ldr.Lookup("type:"+tn, 0)
 		d.defgotype(ts)
 	}
 }
@@ -1662,7 +1662,7 @@ func (d *dwctxt) mkBuiltinType(ctxt *Link, abrv int, tname string) *dwarf.DWDie
 	die := d.newdie(&dwtypes, abrv, tname)
 
 	// Look up type symbol.
-	gotype := d.lookupOrDiag("type." + tname)
+	gotype := d.lookupOrDiag("type:" + tname)
 
 	// Map from die sym to type sym
 	ds := loader.Sym(die.Sym.(dwSym))
@@ -1735,7 +1735,7 @@ func (d *dwctxt) dwarfVisitFunction(fnSym loader.Sym, unit *sym.CompilationUnit)
 
 		rsn := d.ldr.SymName(rsym)
 		tn := rsn[len(dwarf.InfoPrefix):]
-		ts := d.ldr.Lookup("type."+tn, 0)
+		ts := d.ldr.Lookup("type:"+tn, 0)
 		d.defgotype(ts)
 	}
 }
@@ -1760,8 +1760,8 @@ func dwarfGenerateDebugInfo(ctxt *Link) {
 		tdmap:    make(map[loader.Sym]loader.Sym),
 		rtmap:    make(map[loader.Sym]loader.Sym),
 	}
-	d.typeRuntimeEface = d.lookupOrDiag("type.runtime.eface")
-	d.typeRuntimeIface = d.lookupOrDiag("type.runtime.iface")
+	d.typeRuntimeEface = d.lookupOrDiag("type:runtime.eface")
+	d.typeRuntimeIface = d.lookupOrDiag("type:runtime.iface")
 
 	if ctxt.HeadType == objabi.Haix {
 		// Initial map used to store package size for each DWARF section.
@@ -1781,34 +1781,34 @@ func dwarfGenerateDebugInfo(ctxt *Link) {
 	newattr(die, dwarf.DW_AT_encoding, dwarf.DW_CLS_CONSTANT, dwarf.DW_ATE_unsigned, 0)
 	newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, int64(d.arch.PtrSize), 0)
 	newattr(die, dwarf.DW_AT_go_kind, dwarf.DW_CLS_CONSTANT, objabi.KindUintptr, 0)
-	newattr(die, dwarf.DW_AT_go_runtime_type, dwarf.DW_CLS_ADDRESS, 0, dwSym(d.lookupOrDiag("type.uintptr")))
+	newattr(die, dwarf.DW_AT_go_runtime_type, dwarf.DW_CLS_ADDRESS, 0, dwSym(d.lookupOrDiag("type:uintptr")))
 
 	d.uintptrInfoSym = d.mustFind("uintptr")
 
 	// Prototypes needed for type synthesis.
 	prototypedies = map[string]*dwarf.DWDie{
-		"type.runtime.stringStructDWARF": nil,
-		"type.runtime.slice":             nil,
-		"type.runtime.hmap":              nil,
-		"type.runtime.bmap":              nil,
-		"type.runtime.sudog":             nil,
-		"type.runtime.waitq":             nil,
-		"type.runtime.hchan":             nil,
+		"type:runtime.stringStructDWARF": nil,
+		"type:runtime.slice":             nil,
+		"type:runtime.hmap":              nil,
+		"type:runtime.bmap":              nil,
+		"type:runtime.sudog":             nil,
+		"type:runtime.waitq":             nil,
+		"type:runtime.hchan":             nil,
 	}
 
 	// Needed by the prettyprinter code for interface inspection.
 	for _, typ := range []string{
-		"type.runtime._type",
-		"type.runtime.arraytype",
-		"type.runtime.chantype",
-		"type.runtime.functype",
-		"type.runtime.maptype",
-		"type.runtime.ptrtype",
-		"type.runtime.slicetype",
-		"type.runtime.structtype",
-		"type.runtime.interfacetype",
-		"type.runtime.itab",
-		"type.runtime.imethod"} {
+		"type:runtime._type",
+		"type:runtime.arraytype",
+		"type:runtime.chantype",
+		"type:runtime.functype",
+		"type:runtime.maptype",
+		"type:runtime.ptrtype",
+		"type:runtime.slicetype",
+		"type:runtime.structtype",
+		"type:runtime.interfacetype",
+		"type:runtime.itab",
+		"type:runtime.imethod"} {
 		d.defgotype(d.lookupOrDiag(typ))
 	}
 

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

@@ -1531,7 +1531,7 @@ func (ctxt *Link) doelf() {
 	if ctxt.IsShared() {
 		// The go.link.abihashbytes symbol will be pointed at the appropriate
 		// part of the .note.go.abihash section in data.go:func address().
-		s := ldr.LookupOrCreateSym("go.link.abihashbytes", 0)
+		s := ldr.LookupOrCreateSym("go:link.abihashbytes", 0)
 		sb := ldr.MakeSymbolUpdater(s)
 		ldr.SetAttrLocal(s, true)
 		sb.SetType(sym.SRODATA)

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

@@ -385,7 +385,7 @@ func Adddynsym(ldr *loader.Loader, target *Target, syms *ArchSyms, s loader.Sym)
 func fieldtrack(arch *sys.Arch, l *loader.Loader) {
 	var buf bytes.Buffer
 	for i := loader.Sym(1); i < loader.Sym(l.NSym()); i++ {
-		if name := l.SymName(i); strings.HasPrefix(name, "go.track.") {
+		if name := l.SymName(i); strings.HasPrefix(name, "go:track.") {
 			if l.AttrReachable(i) {
 				l.SetAttrSpecial(i, true)
 				l.SetAttrNotInSymbolTable(i, true)

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

@@ -232,7 +232,7 @@ func PrepareAddmoduledata(ctxt *Link) (*loader.SymbolBuilder, loader.Sym) {
 
 	// Create a new init func text symbol. Caller will populate this
 	// sym with arch-specific content.
-	ifs := ctxt.loader.LookupOrCreateSym("go.link.addmoduledata", 0)
+	ifs := ctxt.loader.LookupOrCreateSym("go:link.addmoduledata", 0)
 	initfunc := ctxt.loader.MakeSymbolUpdater(ifs)
 	ctxt.loader.SetAttrReachable(ifs, true)
 	ctxt.loader.SetAttrLocal(ifs, true)
@@ -245,7 +245,7 @@ func PrepareAddmoduledata(ctxt *Link) (*loader.SymbolBuilder, loader.Sym) {
 	ctxt.Textp = append(ctxt.Textp, initfunc.Sym())
 
 	// Create an init array entry
-	amdi := ctxt.loader.LookupOrCreateSym("go.link.addmoduledatainit", 0)
+	amdi := ctxt.loader.LookupOrCreateSym("go:link.addmoduledatainit", 0)
 	initarray_entry := ctxt.loader.MakeSymbolUpdater(amdi)
 	ctxt.loader.SetAttrReachable(amdi, true)
 	ctxt.loader.SetAttrLocal(amdi, true)

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

@@ -926,24 +926,24 @@ func (ctxt *Link) mangleTypeSym() {
 
 // typeSymbolMangle mangles the given symbol name into something shorter.
 //
-// Keep the type.. prefix, which parts of the linker (like the
+// Keep the type:. prefix, which parts of the linker (like the
 // DWARF generator) know means the symbol is not decodable.
-// Leave type.runtime. symbols alone, because other parts of
+// Leave type:runtime. symbols alone, because other parts of
 // the linker manipulates them.
 func typeSymbolMangle(name string) string {
-	if !strings.HasPrefix(name, "type.") {
+	if !strings.HasPrefix(name, "type:") {
 		return name
 	}
-	if strings.HasPrefix(name, "type.runtime.") {
+	if strings.HasPrefix(name, "type:runtime.") {
 		return name
 	}
 	if len(name) <= 14 && !strings.Contains(name, "@") { // Issue 19529
 		return name
 	}
 	hash := notsha256.Sum256([]byte(name))
-	prefix := "type."
+	prefix := "type:"
 	if name[5] == '.' {
-		prefix = "type.."
+		prefix = "type:."
 	}
 	return prefix + base64.StdEncoding.EncodeToString(hash[:6])
 }
@@ -2319,11 +2319,11 @@ func ldshlibsyms(ctxt *Link, shlib string) {
 			continue
 		}
 
-		// Symbols whose names start with "type." are compiler
-		// generated, so make functions with that prefix internal.
+		// Symbols whose names start with "type:" are compiler generated,
+		// so make functions with that prefix internal.
 		ver := 0
 		symname := elfsym.Name // (unmangled) symbol name
-		if elf.ST_TYPE(elfsym.Info) == elf.STT_FUNC && strings.HasPrefix(elfsym.Name, "type.") {
+		if elf.ST_TYPE(elfsym.Info) == elf.STT_FUNC && strings.HasPrefix(elfsym.Name, "type:") {
 			ver = abiInternalVer
 		} else if buildcfg.Experiment.RegabiWrappers && elf.ST_TYPE(elfsym.Info) == elf.STT_FUNC {
 			// Demangle the ABI name. Keep in sync with symtab.go:mangleABIName.
@@ -2357,7 +2357,7 @@ func ldshlibsyms(ctxt *Link, shlib string) {
 			// The decodetype_* functions in decodetype.go need access to
 			// the type data.
 			sname := l.SymName(s)
-			if strings.HasPrefix(sname, "type.") && !strings.HasPrefix(sname, "type..") {
+			if strings.HasPrefix(sname, "type:") && !strings.HasPrefix(sname, "type:.") {
 				su.SetData(readelfsymboldata(ctxt, f, &elfsym))
 			}
 		}

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

@@ -1020,16 +1020,16 @@ func machoShouldExport(ctxt *Link, ldr *loader.Loader, s loader.Sym) bool {
 		return true
 	}
 	name := ldr.SymName(s)
-	if strings.HasPrefix(name, "go.itab.") {
+	if strings.HasPrefix(name, "go:itab.") {
 		return true
 	}
-	if strings.HasPrefix(name, "type.") && !strings.HasPrefix(name, "type..") {
+	if strings.HasPrefix(name, "type:") && !strings.HasPrefix(name, "type:.") {
 		// reduce runtime typemap pressure, but do not
-		// export alg functions (type..*), as these
+		// export alg functions (type:.*), as these
 		// appear in pclntable.
 		return true
 	}
-	if strings.HasPrefix(name, "go.link.pkghash") {
+	if strings.HasPrefix(name, "go:link.pkghash") {
 		return true
 	}
 	return ldr.SymType(s) >= sym.SFirstWritable // only writable sections

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

@@ -222,7 +222,7 @@ func (state *pclntab) generatePCHeader(ctxt *Link) {
 
 		// Write header.
 		// Keep in sync with runtime/symtab.go:pcHeader and package debug/gosym.
-		header.SetUint32(ctxt.Arch, 0, 0xfffffff0)
+		header.SetUint32(ctxt.Arch, 0, 0xfffffff1)
 		header.SetUint8(ctxt.Arch, 6, uint8(ctxt.Arch.MinLC))
 		header.SetUint8(ctxt.Arch, 7, uint8(ctxt.Arch.PtrSize))
 		off := header.SetUint(ctxt.Arch, 8, uint64(state.nfunc))
@@ -627,7 +627,7 @@ func writePCToFunc(ctxt *Link, sb *loader.SymbolBuilder, funcs []loader.Sym, sta
 func writeFuncs(ctxt *Link, sb *loader.SymbolBuilder, funcs []loader.Sym, inlSyms map[loader.Sym]loader.Sym, startLocations, cuOffsets []uint32, nameOffsets map[loader.Sym]uint32) {
 	ldr := ctxt.loader
 	deferReturnSym := ldr.Lookup("runtime.deferreturn", abiInternalVer)
-	gofunc := ldr.Lookup("go.func.*", 0)
+	gofunc := ldr.Lookup("go:func.*", 0)
 	gofuncBase := ldr.SymValue(gofunc)
 	textStart := ldr.SymValue(ldr.Lookup("runtime.text", 0))
 	funcdata := []loader.Sym{}
@@ -716,7 +716,7 @@ func writeFuncs(ctxt *Link, sb *loader.SymbolBuilder, funcs []loader.Sym, inlSym
 			}
 		}
 
-		// Write funcdata refs as offsets from go.func.* and go.funcrel.*.
+		// Write funcdata refs as offsets from go:func.* and go:funcrel.*.
 		funcdata = funcData(ldr, s, fi, inlSyms[s], funcdata)
 		// Missing funcdata will be ^0. See runtime/symtab.go:funcdata.
 		off = int64(startLocations[i] + funcSize + numPCData(ldr, s, fi)*4)
@@ -729,7 +729,7 @@ func writeFuncs(ctxt *Link, sb *loader.SymbolBuilder, funcs []loader.Sym, inlSym
 			}
 
 			if outer := ldr.OuterSym(fdsym); outer != gofunc {
-				panic(fmt.Sprintf("bad carrier sym for symbol %s (funcdata %s#%d), want go.func.* got %s", ldr.SymName(fdsym), ldr.SymName(s), j, ldr.SymName(outer)))
+				panic(fmt.Sprintf("bad carrier sym for symbol %s (funcdata %s#%d), want go:func.* got %s", ldr.SymName(fdsym), ldr.SymName(s), j, ldr.SymName(outer)))
 			}
 			sb.SetUint32(ctxt.Arch, dataoff, uint32(ldr.SymValue(fdsym)-gofuncBase))
 		}

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

@@ -723,7 +723,27 @@ func (f *peFile) writeSymbols(ctxt *Link) {
 
 		// Only windows/386 requires underscore prefix on external symbols.
 		if ctxt.Is386() && ctxt.IsExternal() &&
-			(t == sym.SHOSTOBJ || t == sym.SUNDEFEXT || ldr.AttrCgoExport(s)) {
+			(t == sym.SHOSTOBJ || t == sym.SUNDEFEXT || ldr.AttrCgoExport(s) ||
+				// TODO(cuonglm): remove this hack
+				//
+				// Previously, windows/386 requires underscore prefix on external symbols,
+				// but that's only applied for SHOSTOBJ/SUNDEFEXT or cgo export symbols.
+				// "go.buildid" is STEXT, "type.*" is STYPE, thus they are not prefixed
+				// with underscore.
+				//
+				// In external linking mode, the external linker can't resolve them as
+				// external symbols. But we are lucky that they have "." in their name,
+				// so the external linker see them as Forwarder RVA exports. See:
+				//
+				//  - https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#export-address-table
+				//  - https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/pe-dll.c;h=e7b82ba6ffadf74dc1b9ee71dc13d48336941e51;hb=HEAD#l972)
+				//
+				// CL 317917 changes "." to ":" in symbols name, so theses symbols can not be
+				// found by external linker anymore. So a hacky way is adding the
+				// underscore prefix for these 2 symbols. I don't have enough knowledge to
+				// verify whether adding the underscore for all STEXT/STYPE symbols are
+				// fine, even if it could be, that would be done in future CL.
+				name == "go:buildid" || name == "type:*") {
 			name = "_" + name
 		}
 

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

@@ -472,7 +472,7 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 	var symtype, symtyperel loader.Sym
 	if !ctxt.DynlinkingGo() {
 		if ctxt.UseRelro() && (ctxt.BuildMode == BuildModeCArchive || ctxt.BuildMode == BuildModeCShared || ctxt.BuildMode == BuildModePIE) {
-			s = ldr.CreateSymForUpdate("type.*", 0)
+			s = ldr.CreateSymForUpdate("type:*", 0)
 			s.SetType(sym.STYPE)
 			s.SetSize(0)
 			s.SetAlign(int32(ctxt.Arch.PtrSize))
@@ -484,7 +484,7 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 			s.SetAlign(int32(ctxt.Arch.PtrSize))
 			symtyperel = s.Sym()
 		} else {
-			s = ldr.CreateSymForUpdate("type.*", 0)
+			s = ldr.CreateSymForUpdate("type:*", 0)
 			s.SetType(sym.STYPE)
 			s.SetSize(0)
 			s.SetAlign(int32(ctxt.Arch.PtrSize))
@@ -505,14 +505,14 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 		return s.Sym()
 	}
 	var (
-		symgostring = groupSym("go.string.*", sym.SGOSTRING)
-		symgofunc   = groupSym("go.func.*", sym.SGOFUNC)
+		symgostring = groupSym("go:string.*", sym.SGOSTRING)
+		symgofunc   = groupSym("go:func.*", sym.SGOFUNC)
 		symgcbits   = groupSym("runtime.gcbits.*", sym.SGCBITS)
 	)
 
 	symgofuncrel := symgofunc
 	if ctxt.UseRelro() {
-		symgofuncrel = groupSym("go.funcrel.*", sym.SGOFUNCRELRO)
+		symgofuncrel = groupSym("go:funcrel.*", sym.SGOFUNCRELRO)
 	}
 
 	symt := ldr.CreateSymForUpdate("runtime.symtab", 0)
@@ -538,13 +538,13 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 
 		name := ldr.SymName(s)
 		switch {
-		case strings.HasPrefix(name, "go.string."):
+		case strings.HasPrefix(name, "go:string."):
 			symGroupType[s] = sym.SGOSTRING
 			ldr.SetAttrNotInSymbolTable(s, true)
 			ldr.SetCarrierSym(s, symgostring)
 
 		case strings.HasPrefix(name, "runtime.gcbits."),
-			strings.HasPrefix(name, "type..gcprog."):
+			strings.HasPrefix(name, "type:.gcprog."):
 			symGroupType[s] = sym.SGCBITS
 			ldr.SetAttrNotInSymbolTable(s, true)
 			ldr.SetCarrierSym(s, symgcbits)
@@ -582,10 +582,10 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 				liveness += (ldr.SymSize(s) + int64(align) - 1) &^ (int64(align) - 1)
 			}
 
-		// Note: Check for "type." prefix after checking for .arginfo1 suffix.
-		// That way symbols like "type..eq.[2]interface {}.arginfo1" that belong
-		// in go.func.* end up there.
-		case strings.HasPrefix(name, "type."):
+		// Note: Check for "type:" prefix after checking for .arginfo1 suffix.
+		// That way symbols like "type:.eq.[2]interface {}.arginfo1" that belong
+		// in go:func.* end up there.
+		case strings.HasPrefix(name, "type:"):
 			if !ctxt.DynlinkingGo() {
 				ldr.SetAttrNotInSymbolTable(s, true)
 			}
@@ -604,19 +604,19 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 	}
 
 	if ctxt.BuildMode == BuildModeShared {
-		abihashgostr := ldr.CreateSymForUpdate("go.link.abihash."+filepath.Base(*flagOutfile), 0)
+		abihashgostr := ldr.CreateSymForUpdate("go:link.abihash."+filepath.Base(*flagOutfile), 0)
 		abihashgostr.SetType(sym.SRODATA)
-		hashsym := ldr.LookupOrCreateSym("go.link.abihashbytes", 0)
+		hashsym := ldr.LookupOrCreateSym("go:link.abihashbytes", 0)
 		abihashgostr.AddAddr(ctxt.Arch, hashsym)
 		abihashgostr.AddUint(ctxt.Arch, uint64(ldr.SymSize(hashsym)))
 	}
 	if ctxt.BuildMode == BuildModePlugin || ctxt.CanUsePlugins() {
 		for _, l := range ctxt.Library {
-			s := ldr.CreateSymForUpdate("go.link.pkghashbytes."+l.Pkg, 0)
+			s := ldr.CreateSymForUpdate("go:link.pkghashbytes."+l.Pkg, 0)
 			s.SetType(sym.SRODATA)
 			s.SetSize(int64(len(l.Fingerprint)))
 			s.SetData(l.Fingerprint[:])
-			str := ldr.CreateSymForUpdate("go.link.pkghash."+l.Pkg, 0)
+			str := ldr.CreateSymForUpdate("go:link.pkghash."+l.Pkg, 0)
 			str.SetType(sym.SRODATA)
 			str.AddAddr(ctxt.Arch, s.Sym())
 			str.AddUint(ctxt.Arch, uint64(len(l.Fingerprint)))
@@ -678,7 +678,7 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 	moduledata.AddAddr(ctxt.Arch, ldr.Lookup("runtime.types", 0))
 	moduledata.AddAddr(ctxt.Arch, ldr.Lookup("runtime.etypes", 0))
 	moduledata.AddAddr(ctxt.Arch, ldr.Lookup("runtime.rodata", 0))
-	moduledata.AddAddr(ctxt.Arch, ldr.Lookup("go.func.*", 0))
+	moduledata.AddAddr(ctxt.Arch, ldr.Lookup("go:func.*", 0))
 
 	if ctxt.IsAIX() && ctxt.IsExternal() {
 		// Add R_XCOFFREF relocation to prevent ld's garbage collection of
@@ -695,8 +695,8 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 		// important that the offsets we computed stay unchanged by the external
 		// linker, i.e. all symbols in Textp should not be removed.
 		// Most of them are actually referenced (our deadcode pass ensures that),
-		// except go.buildid which is generated late and not used by the program.
-		addRef("go.buildid")
+		// except go:buildid which is generated late and not used by the program.
+		addRef("go:buildid")
 	}
 
 	// text section information
@@ -717,10 +717,10 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 	moduledata.AddUint(ctxt.Arch, nitablinks)
 	moduledata.AddUint(ctxt.Arch, nitablinks)
 	// The ptab slice
-	if ptab := ldr.Lookup("go.plugin.tabs", 0); ptab != 0 && ldr.AttrReachable(ptab) {
+	if ptab := ldr.Lookup("go:plugin.tabs", 0); ptab != 0 && ldr.AttrReachable(ptab) {
 		ldr.SetAttrLocal(ptab, true)
 		if ldr.SymType(ptab) != sym.SRODATA {
-			panic(fmt.Sprintf("go.plugin.tabs is %v, not SRODATA", ldr.SymType(ptab)))
+			panic(fmt.Sprintf("go:plugin.tabs is %v, not SRODATA", ldr.SymType(ptab)))
 		}
 		nentries := uint64(len(ldr.Data(ptab)) / 8) // sizeof(nameOff) + sizeof(typeOff)
 		moduledata.AddAddr(ctxt.Arch, ptab)
@@ -732,19 +732,19 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 		moduledata.AddUint(ctxt.Arch, 0)
 	}
 	if ctxt.BuildMode == BuildModePlugin {
-		addgostring(ctxt, ldr, moduledata, "go.link.thispluginpath", objabi.PathToPrefix(*flagPluginPath))
+		addgostring(ctxt, ldr, moduledata, "go:link.thispluginpath", objabi.PathToPrefix(*flagPluginPath))
 
-		pkghashes := ldr.CreateSymForUpdate("go.link.pkghashes", 0)
+		pkghashes := ldr.CreateSymForUpdate("go:link.pkghashes", 0)
 		pkghashes.SetLocal(true)
 		pkghashes.SetType(sym.SRODATA)
 
 		for i, l := range ctxt.Library {
 			// pkghashes[i].name
-			addgostring(ctxt, ldr, pkghashes, fmt.Sprintf("go.link.pkgname.%d", i), l.Pkg)
+			addgostring(ctxt, ldr, pkghashes, fmt.Sprintf("go:link.pkgname.%d", i), l.Pkg)
 			// pkghashes[i].linktimehash
-			addgostring(ctxt, ldr, pkghashes, fmt.Sprintf("go.link.pkglinkhash.%d", i), string(l.Fingerprint[:]))
+			addgostring(ctxt, ldr, pkghashes, fmt.Sprintf("go:link.pkglinkhash.%d", i), string(l.Fingerprint[:]))
 			// pkghashes[i].runtimehash
-			hash := ldr.Lookup("go.link.pkghash."+l.Pkg, 0)
+			hash := ldr.Lookup("go:link.pkghash."+l.Pkg, 0)
 			pkghashes.AddAddr(ctxt.Arch, hash)
 		}
 		moduledata.AddAddr(ctxt.Arch, pkghashes.Sym())
@@ -765,22 +765,22 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 			// it something slightly more comprehensible.
 			thismodulename = "the executable"
 		}
-		addgostring(ctxt, ldr, moduledata, "go.link.thismodulename", thismodulename)
+		addgostring(ctxt, ldr, moduledata, "go:link.thismodulename", thismodulename)
 
-		modulehashes := ldr.CreateSymForUpdate("go.link.abihashes", 0)
+		modulehashes := ldr.CreateSymForUpdate("go:link.abihashes", 0)
 		modulehashes.SetLocal(true)
 		modulehashes.SetType(sym.SRODATA)
 
 		for i, shlib := range ctxt.Shlibs {
 			// modulehashes[i].modulename
 			modulename := filepath.Base(shlib.Path)
-			addgostring(ctxt, ldr, modulehashes, fmt.Sprintf("go.link.libname.%d", i), modulename)
+			addgostring(ctxt, ldr, modulehashes, fmt.Sprintf("go:link.libname.%d", i), modulename)
 
 			// modulehashes[i].linktimehash
-			addgostring(ctxt, ldr, modulehashes, fmt.Sprintf("go.link.linkhash.%d", i), string(shlib.Hash))
+			addgostring(ctxt, ldr, modulehashes, fmt.Sprintf("go:link.linkhash.%d", i), string(shlib.Hash))
 
 			// modulehashes[i].runtimehash
-			abihash := ldr.LookupOrCreateSym("go.link.abihash."+modulename, 0)
+			abihash := ldr.LookupOrCreateSym("go:link.abihash."+modulename, 0)
 			ldr.SetAttrReachable(abihash, true)
 			modulehashes.AddAddr(ctxt.Arch, abihash)
 		}
@@ -807,7 +807,7 @@ func (ctxt *Link) symtab(pcln *pclntab) []sym.SymKind {
 	// When linking an object that does not contain the runtime we are
 	// creating the moduledata from scratch and it does not have a
 	// compiler-provided size, so read it from the type data.
-	moduledatatype := ldr.Lookup("type.runtime.moduledata", 0)
+	moduledatatype := ldr.Lookup("type:runtime.moduledata", 0)
 	moduledata.SetSize(decodetypeSize(ctxt.Arch, ldr.Data(moduledatatype)))
 	moduledata.Grow(moduledata.Size())
 
@@ -873,7 +873,7 @@ func mangleABIName(ctxt *Link, ldr *loader.Loader, x loader.Sym, name string) st
 	// except symbols that are exported to C. Type symbols are always
 	// ABIInternal so they are not mangled.
 	if ctxt.IsShared() {
-		if ldr.SymType(x) == sym.STEXT && ldr.SymVersion(x) == sym.SymVerABIInternal && !ldr.AttrCgoExport(x) && !strings.HasPrefix(name, "type.") {
+		if ldr.SymType(x) == sym.STEXT && ldr.SymVersion(x) == sym.SymVerABIInternal && !ldr.AttrCgoExport(x) && !strings.HasPrefix(name, "type:") {
 			name = fmt.Sprintf("%s.abiinternal", name)
 		}
 	}

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

@@ -598,16 +598,16 @@ func xcoffUpdateOuterSize(ctxt *Link, size int64, stype sym.SymKind) {
 		if !ctxt.DynlinkingGo() {
 			// runtime.types size must be removed, as it's a real symbol.
 			tsize := ldr.SymSize(ldr.Lookup("runtime.types", 0))
-			outerSymSize["type.*"] = size - tsize
+			outerSymSize["type:*"] = size - tsize
 		}
 	case sym.SGOSTRING:
-		outerSymSize["go.string.*"] = size
+		outerSymSize["go:string.*"] = size
 	case sym.SGOFUNC:
 		if !ctxt.DynlinkingGo() {
-			outerSymSize["go.func.*"] = size
+			outerSymSize["go:func.*"] = size
 		}
 	case sym.SGOFUNCRELRO:
-		outerSymSize["go.funcrel.*"] = size
+		outerSymSize["go:funcrel.*"] = size
 	case sym.SGCBITS:
 		outerSymSize["runtime.gcbits.*"] = size
 	case sym.SPCLNTAB:
@@ -893,7 +893,7 @@ func putaixsym(ctxt *Link, x loader.Sym, t SymbolType) {
 			syms = xfile.writeSymbolFunc(ctxt, x)
 		} else {
 			// Only runtime.text and runtime.etext come through this way
-			if name != "runtime.text" && name != "runtime.etext" && name != "go.buildid" {
+			if name != "runtime.text" && name != "runtime.etext" && name != "go:buildid" {
 				Exitf("putaixsym: unknown text symbol %s", name)
 			}
 			s := &XcoffSymEnt64{

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

@@ -722,9 +722,9 @@ func (l *Loader) checkdup(name string, r *oReader, li uint32, dup Sym) {
 	// here is that we get different line numbers on formal
 	// params; I am guessing that the pos is being inherited
 	// from the spot where the wrapper is needed.
-	allowed := strings.HasPrefix(name, "go.info.go.interface") ||
-		strings.HasPrefix(name, "go.info.go.builtin") ||
-		strings.HasPrefix(name, "go.debuglines")
+	allowed := strings.HasPrefix(name, "go:info.go.interface") ||
+		strings.HasPrefix(name, "go:info.go.builtin") ||
+		strings.HasPrefix(name, "go:debuglines")
 	if !allowed {
 		l.strictDupMsgs++
 	}
@@ -1704,7 +1704,7 @@ func (l *Loader) OuterSym(i Sym) Sym {
 // SubSym gets the subsymbol for host object loaded symbols.
 func (l *Loader) SubSym(i Sym) Sym {
 	// NB: note -- no check for l.isExternal(), since I am pretty sure
-	// that later phases in the linker set subsym for "type." syms
+	// that later phases in the linker set subsym for "type:" syms
 	return l.sub[i]
 }
 
@@ -1717,7 +1717,7 @@ func (l *Loader) SubSym(i Sym) Sym {
 // emits named string symbols (type SGOSTRING) when compiling a
 // package; after being deduplicated, these symbols are collected into
 // a single unit by assigning them a new carrier symbol named
-// "go.string.*" (which appears in the final symbol table for the
+// "go:string.*" (which appears in the final symbol table for the
 // output load module).
 func (l *Loader) SetCarrierSym(s Sym, c Sym) {
 	if c == 0 {
@@ -2133,7 +2133,7 @@ func (st *loadState) preloadSyms(r *oReader, kind int) {
 			l.SetAttrUsedInIface(gi, true)
 		}
 		if strings.HasPrefix(name, "runtime.") ||
-			(loadingRuntimePkg && strings.HasPrefix(name, "type.")) {
+			(loadingRuntimePkg && strings.HasPrefix(name, "type:")) {
 			if bi := goobj.BuiltinIdx(name, int(osym.ABI())); bi != -1 {
 				// This is a definition of a builtin symbol. Record where it is.
 				l.builtinSyms[bi] = gi

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

@@ -39,9 +39,9 @@ func TestAddMaterializedSymbol(t *testing.T) {
 	or := &dummyOreader
 
 	// Create some syms from a dummy object file symbol to get things going.
-	ts1 := addDummyObjSym(t, ldr, or, "type.uint8")
+	ts1 := addDummyObjSym(t, ldr, or, "type:uint8")
 	ts2 := addDummyObjSym(t, ldr, or, "mumble")
-	ts3 := addDummyObjSym(t, ldr, or, "type.string")
+	ts3 := addDummyObjSym(t, ldr, or, "type:string")
 
 	// Create some external symbols.
 	es1 := ldr.LookupOrCreateSym("extnew1", 0)
@@ -52,7 +52,7 @@ func TestAddMaterializedSymbol(t *testing.T) {
 	if es1x != es1 {
 		t.Fatalf("LookupOrCreateSym lookup: expected %d got %d for second lookup", es1, es1x)
 	}
-	es2 := ldr.LookupOrCreateSym("go.info.type.uint8", 0)
+	es2 := ldr.LookupOrCreateSym("go:info.type.uint8", 0)
 	if es2 == 0 {
 		t.Fatalf("LookupOrCreateSym failed for go.info.type.uint8")
 	}
@@ -252,7 +252,7 @@ func TestAddDataMethods(t *testing.T) {
 	or := &dummyOreader
 
 	// Populate loader with some symbols.
-	addDummyObjSym(t, ldr, or, "type.uint8")
+	addDummyObjSym(t, ldr, or, "type:uint8")
 	ldr.LookupOrCreateSym("hello", 0)
 
 	arch := sys.ArchAMD64
@@ -371,7 +371,7 @@ func TestOuterSub(t *testing.T) {
 	or := &dummyOreader
 
 	// Populate loader with some symbols.
-	addDummyObjSym(t, ldr, or, "type.uint8")
+	addDummyObjSym(t, ldr, or, "type:uint8")
 	es1 := ldr.LookupOrCreateSym("outer", 0)
 	ldr.MakeSymbolUpdater(es1).SetSize(101)
 	es2 := ldr.LookupOrCreateSym("sub1", 0)

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

@@ -156,7 +156,7 @@ func asmb2(ctxt *ld.Link, ldr *loader.Loader) {
 	fns := make([]*wasmFunc, len(ctxt.Textp))
 	for i, fn := range ctxt.Textp {
 		wfn := new(bytes.Buffer)
-		if ldr.SymName(fn) == "go.buildid" {
+		if ldr.SymName(fn) == "go:buildid" {
 			writeUleb128(wfn, 0) // number of sets of locals
 			writeI32Const(wfn, 0)
 			wfn.WriteByte(0x0b) // end
@@ -248,7 +248,7 @@ func writeSecSize(ctxt *ld.Link, sizeOffset int64) {
 
 func writeBuildID(ctxt *ld.Link, buildid []byte) {
 	sizeOffset := writeSecHeader(ctxt, sectionCustom)
-	writeName(ctxt.Out, "go.buildid")
+	writeName(ctxt.Out, "go:buildid")
 	ctxt.Out.Write(buildid)
 	writeSecSize(ctxt, sizeOffset)
 }

src/crypto/tls/link_test.go

@@ -36,8 +36,8 @@ func main() {}
 `,
 			bad: []string{
 				"tls.(*Conn)",
-				"type.crypto/tls.clientHandshakeState",
-				"type.crypto/tls.serverHandshakeState",
+				"type:crypto/tls.clientHandshakeState",
+				"type:crypto/tls.serverHandshakeState",
 			},
 		},
 		{

src/debug/gosym/pclntab.go

@@ -24,6 +24,7 @@ const (
 	ver12
 	ver116
 	ver118
+	ver120
 )
 
 // A LineTable is a data structure mapping program counters to line numbers.
@@ -173,6 +174,7 @@ const (
 	go12magic  = 0xfffffffb
 	go116magic = 0xfffffffa
 	go118magic = 0xfffffff0
+	go120magic = 0xfffffff1
 )
 
 // uintptr returns the pointer-sized value encoded at b.
@@ -229,6 +231,10 @@ func (t *LineTable) parsePclnTab() {
 		t.binary, possibleVersion = binary.LittleEndian, ver118
 	case beMagic == go118magic:
 		t.binary, possibleVersion = binary.BigEndian, ver118
+	case leMagic == go120magic:
+		t.binary, possibleVersion = binary.LittleEndian, ver120
+	case beMagic == go120magic:
+		t.binary, possibleVersion = binary.BigEndian, ver120
 	default:
 		return
 	}
@@ -246,7 +252,7 @@ func (t *LineTable) parsePclnTab() {
 	}
 
 	switch possibleVersion {
-	case ver118:
+	case ver118, ver120:
 		t.nfunctab = uint32(offset(0))
 		t.nfiletab = uint32(offset(1))
 		t.textStart = t.PC // use the start PC instead of reading from the table, which may be unrelocated
@@ -527,7 +533,7 @@ func (t *LineTable) findFileLine(entry uint64, filetab, linetab uint32, filenum,
 	fileStartPC := filePC
 	for t.step(&fp, &filePC, &fileVal, filePC == entry) {
 		fileIndex := fileVal
-		if t.version == ver116 || t.version == ver118 {
+		if t.version == ver116 || t.version == ver118 || t.version == ver120 {
 			fileIndex = int32(t.binary.Uint32(cutab[fileVal*4:]))
 		}
 		if fileIndex == filenum && fileStartPC < filePC {
@@ -626,7 +632,7 @@ func (t *LineTable) go12LineToPC(file string, line int) (pc uint64) {
 		entry := f.entryPC()
 		filetab := f.pcfile()
 		linetab := f.pcln()
-		if t.version == ver116 || t.version == ver118 {
+		if t.version == ver116 || t.version == ver118 || t.version == ver120 {
 			if f.cuOffset() == ^uint32(0) {
 				// skip functions without compilation unit (not real function, or linker generated)
 				continue

src/debug/gosym/symtab.go

@@ -27,6 +27,8 @@ type Sym struct {
 	GoType uint64
 	// If this symbol is a function symbol, the corresponding Func
 	Func *Func
+
+	goVersion version
 }
 
 // Static reports whether this symbol is static (not visible outside its file).
@@ -55,9 +57,16 @@ func (s *Sym) nameWithoutInst() string {
 func (s *Sym) PackageName() string {
 	name := s.nameWithoutInst()
 
-	// A prefix of "type." and "go." is a compiler-generated symbol that doesn't belong to any package.
-	// See variable reservedimports in cmd/compile/internal/gc/subr.go
-	if strings.HasPrefix(name, "go.") || strings.HasPrefix(name, "type.") {
+	// Since go1.20, a prefix of "type:" and "go:" is a compiler-generated symbol,
+	// they do not belong to any package.
+	//
+	// See cmd/compile/internal/base/link.go:ReservedImports variable.
+	if s.goVersion >= ver120 && (strings.HasPrefix(name, "go:") || strings.HasPrefix(name, "type:")) {
+		return ""
+	}
+
+	// For go1.18 and below, the prefix are "type." and "go." instead.
+	if s.goVersion <= ver118 && (strings.HasPrefix(name, "go.") || strings.HasPrefix(name, "type.")) {
 		return ""
 	}
 
@@ -350,6 +359,7 @@ func NewTable(symtab []byte, pcln *LineTable) (*Table, error) {
 		ts.Type = s.typ
 		ts.Value = s.value
 		ts.GoType = s.gotype
+		ts.goVersion = pcln.version
 		switch s.typ {
 		default:
 			// rewrite name to use . instead of · (c2 b7)

src/debug/gosym/symtab_test.go

@@ -62,16 +62,26 @@ func TestRemotePackage(t *testing.T) {
 }
 
 func TestIssue29551(t *testing.T) {
-	symNames := []string{
-		"type..eq.[9]debug/elf.intName",
-		"type..hash.debug/elf.ProgHeader",
-		"type..eq.runtime._panic",
-		"type..hash.struct { runtime.gList; runtime.n int32 }",
-		"go.(*struct { sync.Mutex; math/big.table [64]math/big",
+	tests := []struct {
+		sym     Sym
+		pkgName string
+	}{
+		{Sym{goVersion: ver120, Name: "type:.eq.[9]debug/elf.intName"}, ""},
+		{Sym{goVersion: ver120, Name: "type:.hash.debug/elf.ProgHeader"}, ""},
+		{Sym{goVersion: ver120, Name: "type:.eq.runtime._panic"}, ""},
+		{Sym{goVersion: ver120, Name: "type:.hash.struct { runtime.gList; runtime.n int32 }"}, ""},
+		{Sym{goVersion: ver120, Name: "go:(*struct { sync.Mutex; math/big.table [64]math/big"}, ""},
+		{Sym{goVersion: ver120, Name: "go.uber.org/zap/buffer.(*Buffer).AppendString"}, "go.uber.org/zap/buffer"},
+		{Sym{goVersion: ver118, Name: "type..eq.[9]debug/elf.intName"}, ""},
+		{Sym{goVersion: ver118, Name: "type..hash.debug/elf.ProgHeader"}, ""},
+		{Sym{goVersion: ver118, Name: "type..eq.runtime._panic"}, ""},
+		{Sym{goVersion: ver118, Name: "type..hash.struct { runtime.gList; runtime.n int32 }"}, ""},
+		{Sym{goVersion: ver118, Name: "go.(*struct { sync.Mutex; math/big.table [64]math/big"}, ""},
+		// unfortunate
+		{Sym{goVersion: ver118, Name: "go.uber.org/zap/buffer.(*Buffer).AppendString"}, ""},
 	}
 
-	for _, symName := range symNames {
-		s := Sym{Name: symName}
-		assertString(t, fmt.Sprintf("package of %q", s.Name), s.PackageName(), "")
+	for _, tc := range tests {
+		assertString(t, fmt.Sprintf("package of %q", tc.sym.Name), tc.sym.PackageName(), tc.pkgName)
 	}
 }

src/runtime/symtab.go

@@ -393,7 +393,7 @@ const (
 
 // pcHeader holds data used by the pclntab lookups.
 type pcHeader struct {
-	magic          uint32  // 0xFFFFFFF0
+	magic          uint32  // 0xFFFFFFF1
 	pad1, pad2     uint8   // 0,0
 	minLC          uint8   // min instruction size
 	ptrSize        uint8   // size of a ptr in bytes
@@ -599,7 +599,7 @@ const debugPcln = false
 func moduledataverify1(datap *moduledata) {
 	// Check that the pclntab's format is valid.
 	hdr := datap.pcHeader
-	if hdr.magic != 0xfffffff0 || hdr.pad1 != 0 || hdr.pad2 != 0 ||
+	if hdr.magic != 0xfffffff1 || hdr.pad1 != 0 || hdr.pad2 != 0 ||
 		hdr.minLC != sys.PCQuantum || hdr.ptrSize != goarch.PtrSize || hdr.textStart != datap.text {
 		println("runtime: pcHeader: magic=", hex(hdr.magic), "pad1=", hdr.pad1, "pad2=", hdr.pad2,
 			"minLC=", hdr.minLC, "ptrSize=", hdr.ptrSize, "pcHeader.textStart=", hex(hdr.textStart),

test/codegen/strings.go

@@ -15,7 +15,7 @@ func CountRunes(s string) int { // Issue #24923
 }
 
 func ToByteSlice() []byte { // Issue #24698
-	// amd64:`LEAQ\ttype\.\[3\]uint8`
+	// amd64:`LEAQ\ttype:\[3\]uint8`
 	// amd64:`CALL\truntime\.newobject`
 	// amd64:-`.*runtime.stringtoslicebyte`
 	return []byte("foo")

test/fixedbugs/issue29312.go

@@ -22,14 +22,14 @@
 // The type names for these types are as follows. Because we truncate
 // the name at depth 250, the last few names are all identical:
 //
-//     type.[]*"".pwn
-//     type.[][]*"".pwn
+//     type:[]*"".pwn
+//     type:[][]*"".pwn
 //     ...
-//     type.[][]...[][]*pwn       - 249 total "[]"
-//     type.[][]...[][][]*<...>   - 250 total "[]"
-//     type.[][]...[][][][]<...>  - 251 total "[]"
-//     type.[][]...[][][][]<...>  - 252 total "[]" (but only 251 "[]" in the name)
-//     type.[][]...[][][][]<...>  - 253 total "[]" (but only 251 "[]" in the name)
+//     type:[][]...[][]*pwn       - 249 total "[]"
+//     type:[][]...[][][]*<...>   - 250 total "[]"
+//     type:[][]...[][][][]<...>  - 251 total "[]"
+//     type:[][]...[][][][]<...>  - 252 total "[]" (but only 251 "[]" in the name)
+//     type:[][]...[][][][]<...>  - 253 total "[]" (but only 251 "[]" in the name)
 //
 // Because the names of the last 3 types are all identical, the
 // compiler will generate only a single runtime.slicetype data
@@ -37,7 +37,7 @@
 // generates just the 251-entry one. There aren't any
 // runtime.slicetypes generated for the final two types.
 //
-// The compiler passes type.[]...[]<...> (251 total "[]") to
+// The compiler passes type:[]...[]<...> (251 total "[]") to
 // fmt.Sprintf (instead of the correct 253 one). But the data
 // structure at runtime actually has 253 nesting levels. So we end up
 // calling String on something that is of type [][]*pwn instead of