[dev.link] cmd/link: remove old objs from host obj loaders

Change-Id: I9ee853e37090ea015aba817d9aeb2f4cc9ff5a1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/206539
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

5 files changed, 55 insertions, 145 deletions

diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index 0bd9a8c735..8d9104f0cb 100644
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -1692,107 +1692,55 @@ 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
-		if *flagNewobj {
-			ldelf := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-				textp, flags, err := loadelf.Load(ctxt.loader, ctxt.Arch, ctxt.Syms, f, pkg, length, pn, ehdr.flags)
-				if err != nil {
-					Errorf(nil, "%v", err)
-					return
-				}
-				ehdr.flags = flags
-				ctxt.Textp = append(ctxt.Textp, textp...)
-			}
-			return ldhostobj(ldelf, ctxt.HeadType, f, pkg, length, pn, file)
-		} else {
-			ldelf := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-				textp, flags, err := loadelf.LoadOld(ctxt.Arch, ctxt.Syms, f, pkg, length, pn, ehdr.flags)
-				if err != nil {
-					Errorf(nil, "%v", err)
-					return
-				}
-				ehdr.flags = flags
-				ctxt.Textp = append(ctxt.Textp, textp...)
+		ldelf := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
+			textp, flags, err := loadelf.Load(ctxt.loader, ctxt.Arch, ctxt.Syms, f, pkg, length, pn, ehdr.flags)
+			if err != nil {
+				Errorf(nil, "%v", err)
+				return
 			}
-			return ldhostobj(ldelf, ctxt.HeadType, f, pkg, length, pn, file)
+			ehdr.flags = flags
+			ctxt.Textp = append(ctxt.Textp, textp...)
 		}
+		return ldhostobj(ldelf, ctxt.HeadType, f, pkg, length, pn, file)
 	}
 
 	if magic&^1 == 0xfeedface || magic&^0x01000000 == 0xcefaedfe {
-		if *flagNewobj {
-			ldmacho := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-				textp, err := loadmacho.Load(ctxt.loader, ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
-				if err != nil {
-					Errorf(nil, "%v", err)
-					return
-				}
-				ctxt.Textp = append(ctxt.Textp, textp...)
-			}
-			return ldhostobj(ldmacho, ctxt.HeadType, f, pkg, length, pn, file)
-		} else {
-			ldmacho := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-				textp, err := loadmacho.LoadOld(ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
-				if err != nil {
-					Errorf(nil, "%v", err)
-					return
-				}
-				ctxt.Textp = append(ctxt.Textp, textp...)
+		ldmacho := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
+			textp, err := loadmacho.Load(ctxt.loader, ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
+			if err != nil {
+				Errorf(nil, "%v", err)
+				return
 			}
-			return ldhostobj(ldmacho, ctxt.HeadType, f, pkg, length, pn, file)
+			ctxt.Textp = append(ctxt.Textp, textp...)
 		}
+		return ldhostobj(ldmacho, ctxt.HeadType, f, pkg, length, pn, file)
 	}
 
 	if c1 == 0x4c && c2 == 0x01 || c1 == 0x64 && c2 == 0x86 {
-		if *flagNewobj {
-			ldpe := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-				textp, rsrc, err := loadpe.Load(ctxt.loader, ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
-				if err != nil {
-					Errorf(nil, "%v", err)
-					return
-				}
-				if rsrc != nil {
-					setpersrc(ctxt, rsrc)
-				}
-				ctxt.Textp = append(ctxt.Textp, textp...)
+		ldpe := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
+			textp, rsrc, err := loadpe.Load(ctxt.loader, ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
+			if err != nil {
+				Errorf(nil, "%v", err)
+				return
 			}
-			return ldhostobj(ldpe, ctxt.HeadType, f, pkg, length, pn, file)
-		} else {
-			ldpe := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-				textp, rsrc, err := loadpe.LoadOld(ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
-				if err != nil {
-					Errorf(nil, "%v", err)
-					return
-				}
-				if rsrc != nil {
-					setpersrc(ctxt, rsrc)
-				}
-				ctxt.Textp = append(ctxt.Textp, textp...)
+			if rsrc != nil {
+				setpersrc(ctxt, rsrc)
 			}
-			return ldhostobj(ldpe, ctxt.HeadType, f, pkg, length, pn, file)
+			ctxt.Textp = append(ctxt.Textp, textp...)
 		}
+		return ldhostobj(ldpe, ctxt.HeadType, f, pkg, length, pn, file)
 	}
 
 	if c1 == 0x01 && (c2 == 0xD7 || c2 == 0xF7) {
-		if *flagNewobj {
-			ldxcoff := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-				textp, err := loadxcoff.Load(ctxt.loader, ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
-				if err != nil {
-					Errorf(nil, "%v", err)
-					return
-				}
-				ctxt.Textp = append(ctxt.Textp, textp...)
-			}
-			return ldhostobj(ldxcoff, ctxt.HeadType, f, pkg, length, pn, file)
-		} else {
-			ldxcoff := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
-				textp, err := loadxcoff.LoadOld(ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
-				if err != nil {
-					Errorf(nil, "%v", err)
-					return
-				}
-				ctxt.Textp = append(ctxt.Textp, textp...)
+		ldxcoff := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
+			textp, err := loadxcoff.Load(ctxt.loader, ctxt.Arch, ctxt.Syms, f, pkg, length, pn)
+			if err != nil {
+				Errorf(nil, "%v", err)
+				return
 			}
-			return ldhostobj(ldxcoff, ctxt.HeadType, f, pkg, length, pn, file)
+			ctxt.Textp = append(ctxt.Textp, textp...)
 		}
+		return ldhostobj(ldxcoff, ctxt.HeadType, f, pkg, length, pn, file)
 	}
 
 	/* check the header */
diff --git a/src/cmd/link/internal/loadelf/ldelf.go b/src/cmd/link/internal/loadelf/ldelf.go
index 072eaf00c8..c32f32c32b 100644
--- a/src/cmd/link/internal/loadelf/ldelf.go
+++ b/src/cmd/link/internal/loadelf/ldelf.go
@@ -452,20 +452,7 @@ func parseArmAttributes(e binary.ByteOrder, data []byte) (found bool, ehdrFlags
 	return found, ehdrFlags, nil
 }
 
-func Load(l *loader.Loader, arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length int64, pn string, flags uint32) ([]*sym.Symbol, uint32, error) {
-	newSym := func(name string, version int) *sym.Symbol {
-		return l.LookupOrCreate(name, version, syms)
-	}
-	return load(arch, syms.IncVersion(), newSym, newSym, f, pkg, length, pn, flags)
-}
-
-func LoadOld(arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length int64, pn string, flags uint32) ([]*sym.Symbol, uint32, error) {
-	return load(arch, syms.IncVersion(), syms.Newsym, syms.Lookup, f, pkg, length, pn, flags)
-}
-
-type lookupFunc func(string, int) *sym.Symbol
-
-// load loads the ELF file pn from f.
+// Load loads the ELF file pn from f.
 // Symbols are written into syms, and a slice of the text symbols is returned.
 //
 // On ARM systems, Load will attempt to determine what ELF header flags to
@@ -473,7 +460,11 @@ type lookupFunc func(string, int) *sym.Symbol
 // parameter initEhdrFlags contains the current header flags for the output
 // object, and the returned ehdrFlags contains what this Load function computes.
 // TODO: find a better place for this logic.
-func load(arch *sys.Arch, localSymVersion int, newSym, lookup lookupFunc, f *bio.Reader, pkg string, length int64, pn string, initEhdrFlags uint32) (textp []*sym.Symbol, ehdrFlags uint32, err error) {
+func Load(l *loader.Loader, arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length int64, pn string, initEhdrFlags uint32) (textp []*sym.Symbol, ehdrFlags uint32, err error) {
+	localSymVersion := syms.IncVersion()
+	lookup := func(name string, version int) *sym.Symbol {
+		return l.LookupOrCreate(name, version, syms)
+	}
 	errorf := func(str string, args ...interface{}) ([]*sym.Symbol, uint32, error) {
 		return nil, 0, fmt.Errorf("loadelf: %s: %v", pn, fmt.Sprintf(str, args...))
 	}
@@ -767,7 +758,7 @@ func load(arch *sys.Arch, localSymVersion int, newSym, lookup lookupFunc, f *bio
 
 	for i := 1; i < elfobj.nsymtab; i++ {
 		var elfsym ElfSym
-		if err := readelfsym(newSym, lookup, arch, elfobj, i, &elfsym, 1, localSymVersion); err != nil {
+		if err := readelfsym(lookup, arch, elfobj, i, &elfsym, 1, localSymVersion); err != nil {
 			return errorf("%s: malformed elf file: %v", pn, err)
 		}
 		symbols[i] = elfsym.sym
@@ -938,7 +929,7 @@ func load(arch *sys.Arch, localSymVersion int, newSym, lookup lookupFunc, f *bio
 				rp.Sym = nil
 			} else {
 				var elfsym ElfSym
-				if err := readelfsym(newSym, lookup, arch, elfobj, int(info>>32), &elfsym, 0, 0); err != nil {
+				if err := readelfsym(lookup, arch, elfobj, int(info>>32), &elfsym, 0, 0); err != nil {
 					return errorf("malformed elf file: %v", err)
 				}
 				elfsym.sym = symbols[info>>32]
@@ -1015,7 +1006,7 @@ func elfmap(elfobj *ElfObj, sect *ElfSect) (err error) {
 	return nil
 }
 
-func readelfsym(newSym, lookup lookupFunc, arch *sys.Arch, elfobj *ElfObj, i int, elfsym *ElfSym, needSym int, localSymVersion int) (err error) {
+func readelfsym(lookup func(string, int) *sym.Symbol, arch *sys.Arch, elfobj *ElfObj, i int, elfsym *ElfSym, needSym int, localSymVersion int) (err error) {
 	if i >= elfobj.nsymtab || i < 0 {
 		err = fmt.Errorf("invalid elf symbol index")
 		return err
@@ -1101,7 +1092,7 @@ func readelfsym(newSym, lookup lookupFunc, arch *sys.Arch, elfobj *ElfObj, i int
 				// local names and hidden global names are unique
 				// and should only be referenced by their index, not name, so we
 				// don't bother to add them into the hash table
-				s = newSym(elfsym.name, localSymVersion)
+				s = lookup(elfsym.name, localSymVersion)
 
 				s.Attr |= sym.AttrVisibilityHidden
 			}
diff --git a/src/cmd/link/internal/loadmacho/ldmacho.go b/src/cmd/link/internal/loadmacho/ldmacho.go
index deea27bebb..a98b962210 100644
--- a/src/cmd/link/internal/loadmacho/ldmacho.go
+++ b/src/cmd/link/internal/loadmacho/ldmacho.go
@@ -421,20 +421,10 @@ func macholoadsym(m *ldMachoObj, symtab *ldMachoSymtab) int {
 	return 0
 }
 
-func Load(l *loader.Loader, arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length int64, pn string) ([]*sym.Symbol, error) {
-	newSym := func(name string, version int) *sym.Symbol {
-		return l.LookupOrCreate(name, version, syms)
-	}
-	return load(arch, syms.IncVersion(), newSym, f, pkg, length, pn)
-}
-
-func LoadOld(arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, err error) {
-	return load(arch, syms.IncVersion(), syms.Lookup, f, pkg, length, pn)
-}
-
-// load the Mach-O file pn from f.
+// Load the Mach-O file pn from f.
 // Symbols are written into syms, and a slice of the text symbols is returned.
-func load(arch *sys.Arch, localSymVersion int, lookup func(string, int) *sym.Symbol, f *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, err error) {
+func Load(l *loader.Loader, arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, err error) {
+	localSymVersion := syms.IncVersion()
 	errorf := func(str string, args ...interface{}) ([]*sym.Symbol, error) {
 		return nil, fmt.Errorf("loadmacho: %v: %v", pn, fmt.Sprintf(str, args...))
 	}
@@ -570,7 +560,7 @@ func load(arch *sys.Arch, localSymVersion int, lookup func(string, int) *sym.Sym
 			continue
 		}
 		name := fmt.Sprintf("%s(%s/%s)", pkg, sect.segname, sect.name)
-		s := lookup(name, localSymVersion)
+		s := l.LookupOrCreate(name, localSymVersion, syms)
 		if s.Type != 0 {
 			return errorf("duplicate %s/%s", sect.segname, sect.name)
 		}
@@ -619,7 +609,7 @@ func load(arch *sys.Arch, localSymVersion int, lookup func(string, int) *sym.Sym
 		if machsym.type_&N_EXT == 0 {
 			v = localSymVersion
 		}
-		s := lookup(name, v)
+		s := l.LookupOrCreate(name, v, syms)
 		if machsym.type_&N_EXT == 0 {
 			s.Attr |= sym.AttrDuplicateOK
 		}
diff --git a/src/cmd/link/internal/loadpe/ldpe.go b/src/cmd/link/internal/loadpe/ldpe.go
index 353f6e0863..32f043ceeb 100644
--- a/src/cmd/link/internal/loadpe/ldpe.go
+++ b/src/cmd/link/internal/loadpe/ldpe.go
@@ -145,21 +145,14 @@ func (f *peBiobuf) ReadAt(p []byte, off int64) (int, error) {
 	return n, nil
 }
 
+// Load loads the PE file pn from input.
+// Symbols are written into syms, and a slice of the text symbols is returned.
+// If an .rsrc section is found, its symbol is returned as rsrc.
 func Load(l *loader.Loader, arch *sys.Arch, syms *sym.Symbols, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, rsrc *sym.Symbol, err error) {
 	lookup := func(name string, version int) *sym.Symbol {
 		return l.LookupOrCreate(name, version, syms)
 	}
-	return load(arch, lookup, syms.IncVersion(), input, pkg, length, pn)
-}
-
-func LoadOld(arch *sys.Arch, syms *sym.Symbols, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, rsrc *sym.Symbol, err error) {
-	return load(arch, syms.Lookup, syms.IncVersion(), input, pkg, length, pn)
-}
-
-// load loads the PE file pn from input.
-// Symbols are written into syms, and a slice of the text symbols is returned.
-// If an .rsrc section is found, its symbol is returned as rsrc.
-func load(arch *sys.Arch, lookup func(string, int) *sym.Symbol, localSymVersion int, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, rsrc *sym.Symbol, err error) {
+	localSymVersion := syms.IncVersion()
 	sectsyms := make(map[*pe.Section]*sym.Symbol)
 	sectdata := make(map[*pe.Section][]byte)
 
diff --git a/src/cmd/link/internal/loadxcoff/ldxcoff.go b/src/cmd/link/internal/loadxcoff/ldxcoff.go
index 759b1769dd..f0e3567f9c 100644
--- a/src/cmd/link/internal/loadxcoff/ldxcoff.go
+++ b/src/cmd/link/internal/loadxcoff/ldxcoff.go
@@ -39,22 +39,10 @@ func (f *xcoffBiobuf) ReadAt(p []byte, off int64) (int, error) {
 	return n, nil
 }
 
-// Load loads xcoff files with the indexed object files.
-func Load(l *loader.Loader, arch *sys.Arch, syms *sym.Symbols, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, err error) {
-	lookup := func(name string, version int) *sym.Symbol {
-		return l.LookupOrCreate(name, version, syms)
-	}
-	return load(arch, lookup, syms.IncVersion(), input, pkg, length, pn)
-}
-
-// LoadOld uses the old version of object loading.
-func LoadOld(arch *sys.Arch, syms *sym.Symbols, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, err error) {
-	return load(arch, syms.Lookup, syms.IncVersion(), input, pkg, length, pn)
-}
-
 // loads the Xcoff file pn from f.
 // Symbols are written into syms, and a slice of the text symbols is returned.
-func load(arch *sys.Arch, lookup func(string, int) *sym.Symbol, localSymVersion int, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, err error) {
+func Load(l *loader.Loader, arch *sys.Arch, syms *sym.Symbols, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, err error) {
+	localSymVersion := syms.IncVersion()
 	errorf := func(str string, args ...interface{}) ([]*sym.Symbol, error) {
 		return nil, fmt.Errorf("loadxcoff: %v: %v", pn, fmt.Sprintf(str, args...))
 	}
@@ -75,7 +63,7 @@ func load(arch *sys.Arch, lookup func(string, int) *sym.Symbol, localSymVersion
 		lds := new(ldSection)
 		lds.Section = *sect
 		name := fmt.Sprintf("%s(%s)", pkg, lds.Name)
-		s := lookup(name, localSymVersion)
+		s := l.LookupOrCreate(name, localSymVersion, syms)
 
 		switch lds.Type {
 		default:
@@ -113,7 +101,7 @@ func load(arch *sys.Arch, lookup func(string, int) *sym.Symbol, localSymVersion
 			continue
 		}
 
-		s := lookup(sx.Name, 0)
+		s := l.LookupOrCreate(sx.Name, 0, syms)
 
 		// Text symbol
 		if s.Type == sym.STEXT {
@@ -135,7 +123,7 @@ func load(arch *sys.Arch, lookup func(string, int) *sym.Symbol, localSymVersion
 		for i, rx := range sect.Relocs {
 			r := &rs[i]
 
-			r.Sym = lookup(rx.Symbol.Name, 0)
+			r.Sym = l.LookupOrCreate(rx.Symbol.Name, 0, syms)
 			if uint64(int32(rx.VirtualAddress)) != rx.VirtualAddress {
 				return errorf("virtual address of a relocation is too big: 0x%x", rx.VirtualAddress)
 			}