cmd/link: remove ctxt from objfile reader

Preparation for moving the object file reader to its own package.

For #22095

Change-Id: I31fe4a10a2c465f8ea4bf548f40918807e4ec6b5
Reviewed-on: https://go-review.googlesource.com/67314
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

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

@@ -1425,7 +1425,8 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *Library, length int64, pn string, fil
 	ldpkg(ctxt, f, pkg, import1-import0-2, pn, whence) // -2 for !\n
 	f.Seek(import1, 0)
 
-	LoadObjFile(ctxt, f, lib, eof-f.Offset(), pn)
+	LoadObjFile(ctxt.Arch, ctxt.Syms, f, lib, eof-f.Offset(), pn)
+	lib.addImports(ctxt, pn)
 	return nil
 }
 

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

@@ -206,21 +206,33 @@ func (l *Link) Logf(format string, args ...interface{}) {
 }
 
 type Library struct {
-	Objref      string
-	Srcref      string
-	File        string
-	Pkg         string
-	Shlib       string
-	hash        string
-	imports     []*Library
-	textp       []*Symbol // text symbols defined in this library
-	dupTextSyms []*Symbol // dupok text symbols defined in this library
+	Objref        string
+	Srcref        string
+	File          string
+	Pkg           string
+	Shlib         string
+	hash          string
+	importStrings []string
+	imports       []*Library
+	textp         []*Symbol // text symbols defined in this library
+	dupTextSyms   []*Symbol // dupok text symbols defined in this library
 }
 
 func (l Library) String() string {
 	return l.Pkg
 }
 
+func (l *Library) addImports(ctxt *Link, pn string) {
+	pkg := objabi.PathToPrefix(l.Pkg)
+	for _, importStr := range l.importStrings {
+		lib := addlib(ctxt, pkg, pn, importStr)
+		if lib != nil {
+			l.imports = append(l.imports, lib)
+		}
+	}
+	l.importStrings = nil
+}
+
 type FuncInfo struct {
 	Args        int32
 	Locals      int32

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

@@ -12,6 +12,7 @@ import (
 	"cmd/internal/bio"
 	"cmd/internal/dwarf"
 	"cmd/internal/objabi"
+	"cmd/internal/sys"
 	"crypto/sha1"
 	"encoding/base64"
 	"io"
@@ -30,7 +31,8 @@ var emptyPkg = []byte(`"".`)
 // objReader reads Go object files.
 type objReader struct {
 	rd              *bufio.Reader
-	ctxt            *Link
+	arch            *sys.Arch
+	syms            *Symbols
 	lib             *Library
 	pn              string
 	dupSym          *Symbol
@@ -50,16 +52,16 @@ type objReader struct {
 	file        []*Symbol
 }
 
-func LoadObjFile(ctxt *Link, f *bio.Reader, lib *Library, length int64, pn string) {
-
+func LoadObjFile(arch *sys.Arch, syms *Symbols, f *bio.Reader, lib *Library, length int64, pn string) {
 	start := f.Offset()
 	r := &objReader{
 		rd:              f.Reader,
 		lib:             lib,
-		ctxt:            ctxt,
+		arch:            arch,
+		syms:            syms,
 		pn:              pn,
 		dupSym:          &Symbol{Name: ".dup"},
-		localSymVersion: ctxt.Syms.IncVersion(),
+		localSymVersion: syms.IncVersion(),
 	}
 	r.loadObjFile()
 	if f.Offset() != start+length {
@@ -68,8 +70,6 @@ func LoadObjFile(ctxt *Link, f *bio.Reader, lib *Library, length int64, pn strin
 }
 
 func (r *objReader) loadObjFile() {
-	pkg := objabi.PathToPrefix(r.lib.Pkg)
-
 	// Magic header
 	var buf [8]uint8
 	r.readFull(buf[:])
@@ -89,10 +89,7 @@ func (r *objReader) loadObjFile() {
 		if lib == "" {
 			break
 		}
-		l := addlib(r.ctxt, pkg, r.pn, lib)
-		if l != nil {
-			r.lib.imports = append(r.lib.imports, l)
-		}
+		r.lib.importStrings = append(r.lib.importStrings, lib)
 	}
 
 	// Symbol references
@@ -386,7 +383,7 @@ func (r *objReader) readRef() {
 	if v == 1 {
 		v = r.localSymVersion
 	}
-	s := r.ctxt.Syms.Lookup(name, v)
+	s := r.syms.Lookup(name, v)
 	r.refs = append(r.refs, s)
 
 	if s == nil || v != 0 {
@@ -404,9 +401,9 @@ func (r *objReader) readRef() {
 			if uint64(uint32(x)) != x {
 				log.Panicf("$-symbol %s too large: %d", s.Name, x)
 			}
-			s.AddUint32(r.ctxt.Arch, uint32(x))
+			s.AddUint32(r.arch, uint32(x))
 		case "$f64.", "$i64.":
-			s.AddUint64(r.ctxt.Arch, x)
+			s.AddUint64(r.arch, x)
 		default:
 			log.Panicf("unrecognized $-symbol: %s", s.Name)
 		}