[dev.link] cmd/link: delete sym.Symbols

Now the only thing it does is to track versions. Move it to ctxt.
And delete sym.Symbols.

Change-Id: Ie6b974f9bf79c4f33ace02213dcb89463eadd26a
Reviewed-on: https://go-review.googlesource.com/c/go/+/234884
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>

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

@@ -151,8 +151,9 @@ func (ctxt *Link) setArchSyms() {
 		// *sym.Symbol symbols. Symbols that are assigned this final
 		// version are not going to have TOC references, so it should
 		// be ok for them to inherit an invalid .TOC. symbol.
-		ctxt.DotTOC = make([]loader.Sym, ctxt.Syms.MaxVersion()+2)
-		for i := 0; i <= ctxt.Syms.MaxVersion(); i++ {
+		// TODO: revisit the +2, now that loadlibfull is gone.
+		ctxt.DotTOC = make([]loader.Sym, ctxt.MaxVersion()+2)
+		for i := 0; i <= ctxt.MaxVersion(); i++ {
 			if i >= 2 && i < sym.SymVerStatic { // these versions are not used currently
 				continue
 			}
@@ -1809,7 +1810,7 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string,
 	magic := uint32(c1)<<24 | uint32(c2)<<16 | uint32(c3)<<8 | uint32(c4)
 	if magic == 0x7f454c46 { // \x7F E L F
 		ldelf := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-			textp, flags, err := loadelf.Load(ctxt.loader, ctxt.Arch, ctxt.Syms.IncVersion(), f, pkg, length, pn, ehdr.flags)
+			textp, flags, err := loadelf.Load(ctxt.loader, ctxt.Arch, ctxt.IncVersion(), f, pkg, length, pn, ehdr.flags)
 			if err != nil {
 				Errorf(nil, "%v", err)
 				return
@@ -1822,7 +1823,7 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string,
 
 	if magic&^1 == 0xfeedface || magic&^0x01000000 == 0xcefaedfe {
 		ldmacho := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-			textp, err := loadmacho.Load(ctxt.loader, ctxt.Arch, ctxt.Syms.IncVersion(), f, pkg, length, pn)
+			textp, err := loadmacho.Load(ctxt.loader, ctxt.Arch, ctxt.IncVersion(), f, pkg, length, pn)
 			if err != nil {
 				Errorf(nil, "%v", err)
 				return
@@ -1834,7 +1835,7 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string,
 
 	if c1 == 0x4c && c2 == 0x01 || c1 == 0x64 && c2 == 0x86 {
 		ldpe := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-			textp, rsrc, err := loadpe.Load(ctxt.loader, ctxt.Arch, ctxt.Syms.IncVersion(), f, pkg, length, pn)
+			textp, rsrc, err := loadpe.Load(ctxt.loader, ctxt.Arch, ctxt.IncVersion(), f, pkg, length, pn)
 			if err != nil {
 				Errorf(nil, "%v", err)
 				return
@@ -1849,7 +1850,7 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string,
 
 	if c1 == 0x01 && (c2 == 0xD7 || c2 == 0xF7) {
 		ldxcoff := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-			textp, err := loadxcoff.Load(ctxt.loader, ctxt.Arch, ctxt.Syms.IncVersion(), f, pkg, length, pn)
+			textp, err := loadxcoff.Load(ctxt.loader, ctxt.Arch, ctxt.IncVersion(), f, pkg, length, pn)
 			if err != nil {
 				Errorf(nil, "%v", err)
 				return
@@ -1941,7 +1942,7 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string,
 	ldpkg(ctxt, f, lib, import1-import0-2, pn) // -2 for !\n
 	f.MustSeek(import1, 0)
 
-	fingerprint := ctxt.loader.Preload(ctxt.Syms, f, lib, unit, eof-f.Offset())
+	fingerprint := ctxt.loader.Preload(ctxt.IncVersion(), f, lib, unit, eof-f.Offset())
 	if !fingerprint.IsZero() { // Assembly objects don't have fingerprints. Ignore them.
 		// Check fingerprint, to ensure the importing and imported packages
 		// have consistent view of symbol indices.

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

@@ -57,7 +57,7 @@ type Link struct {
 	outSem chan int // limits the number of output writers
 	Out    *OutBuf
 
-	Syms *sym.Symbols
+	version int // current version number for static/file-local symbols
 
 	Debugvlog int
 	Bso       *bufio.Writer
@@ -133,3 +133,14 @@ func addImports(ctxt *Link, l *sym.Library, pn string) {
 	}
 	l.Autolib = nil
 }
+
+// Allocate a new version (i.e. symbol namespace).
+func (ctxt *Link) IncVersion() int {
+	ctxt.version++
+	return ctxt.version - 1
+}
+
+// returns the maximum version number
+func (ctxt *Link) MaxVersion() int {
+	return ctxt.version
+}

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

@@ -44,7 +44,7 @@ func linknew(arch *sys.Arch) *Link {
 	ler := loader.ErrorReporter{AfterErrorAction: afterErrorAction}
 	ctxt := &Link{
 		Target:        Target{Arch: arch},
-		Syms:          sym.NewSymbols(),
+		version:       sym.SymVerStatic,
 		outSem:        make(chan int, 2*runtime.GOMAXPROCS(0)),
 		Out:           NewOutBuf(arch),
 		LibraryByPkg:  make(map[string]*sym.Library),

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

@@ -1911,7 +1911,7 @@ func (l *Loader) FuncInfo(i Sym) FuncInfo {
 // Does not add non-package symbols yet, which will be done in LoadNonpkgSyms.
 // Does not read symbol data.
 // Returns the fingerprint of the object.
-func (l *Loader) Preload(syms *sym.Symbols, f *bio.Reader, lib *sym.Library, unit *sym.CompilationUnit, length int64) goobj2.FingerprintType {
+func (l *Loader) Preload(localSymVersion int, f *bio.Reader, lib *sym.Library, unit *sym.CompilationUnit, length int64) goobj2.FingerprintType {
 	roObject, readonly, err := f.Slice(uint64(length))
 	if err != nil {
 		log.Fatal("cannot read object file:", err)
@@ -1923,7 +1923,6 @@ func (l *Loader) Preload(syms *sym.Symbols, f *bio.Reader, lib *sym.Library, uni
 		}
 		panic("cannot read object file")
 	}
-	localSymVersion := syms.IncVersion()
 	pkgprefix := objabi.PathToPrefix(lib.Pkg) + "."
 	ndef := r.NSym()
 	nnonpkgdef := r.NNonpkgdef()

src/cmd/link/internal/sym/symbols.go

@@ -1,53 +0,0 @@
-// Derived from Inferno utils/6l/l.h and related files.
-// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/l.h
-//
-//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
-//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-//	Portions Copyright © 1997-1999 Vita Nuova Limited
-//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-//	Portions Copyright © 2004,2006 Bruce Ellis
-//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-//	Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package sym
-
-type Symbols struct {
-	// Symbol lookup based on name and indexed by version.
-	versions int
-}
-
-func NewSymbols() *Symbols {
-	return &Symbols{
-		versions: SymVerStatic,
-	}
-}
-
-// Allocate a new version (i.e. symbol namespace).
-func (syms *Symbols) IncVersion() int {
-	syms.versions++
-	return syms.versions - 1
-}
-
-// returns the maximum version number
-func (syms *Symbols) MaxVersion() int {
-	return syms.versions
-}