cmd/link: remove ABI aliases

It is now gone. Change-Id: I59f68b324af706476695de2f291dd3aa5734e192 Reviewed-on: https://go-review.googlesource.com/c/go/+/351332 Trust: Cherry Mui <[email protected]> Run-TryBot: Cherry Mui <[email protected]> TryBot-Result: Go Bot <[email protected]> Reviewed-by: Than McIntosh <[email protected]>
zegl · Sep 22, 2021 · 55d22f7 · 55d22f7
1 parent a630783
commit 55d22f7
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Showing 16 changed files with 23 additions and 66 deletions.
diff --git a/src/cmd/internal/objabi/symkind.go b/src/cmd/internal/objabi/symkind.go
@@ -65,13 +65,6 @@ const (
 	SDWARFRANGE
 	SDWARFLOC
 	SDWARFLINES
-	// ABI alias. An ABI alias symbol is an empty symbol with a
-	// single relocation with 0 size that references the native
-	// function implementation symbol.
-	//
-	// TODO(austin): Remove this and all uses once the compiler
-	// generates real ABI wrappers rather than symbol aliases.
-	SABIALIAS
 	// Coverage instrumentation counter for libfuzzer.
 	SLIBFUZZER_EXTRA_COUNTER
 	// Update cmd/link/internal/sym/AbiSymKindToSymKind for new SymKind values.

diff --git a/src/cmd/internal/objabi/symkind_string.go b/src/cmd/internal/objabi/symkind_string.go
diff --git a/src/cmd/link/internal/arm/asm.go b/src/cmd/link/internal/arm/asm.go
@@ -544,7 +544,6 @@ func gentrampdyn(arch *sys.Arch, tramp *loader.SymbolBuilder, target loader.Sym,
 
 func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) (o int64, nExtReloc int, ok bool) {
 	rs := r.Sym()
-	rs = ldr.ResolveABIAlias(rs)
 	if target.IsExternal() {
 		switch r.Type() {
 		case objabi.R_CALLARM:
@@ -592,7 +591,7 @@ func archrelocvariant(*ld.Target, *loader.Loader, loader.Reloc, sym.RelocVariant
 }
 
 func extreloc(target *ld.Target, ldr *loader.Loader, r loader.Reloc, s loader.Sym) (loader.ExtReloc, bool) {
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 	var rr loader.ExtReloc
 	switch r.Type() {
 	case objabi.R_CALLARM:

diff --git a/src/cmd/link/internal/arm64/asm.go b/src/cmd/link/internal/arm64/asm.go
@@ -668,7 +668,7 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade
 	const noExtReloc = 0
 	const isOk = true
 
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 
 	if target.IsExternal() {
 		nExtReloc := 0

diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
@@ -113,7 +113,6 @@ func trampoline(ctxt *Link, s loader.Sym) {
 		if !ldr.AttrReachable(rs) || ldr.SymType(rs) == sym.Sxxx {
 			continue // something is wrong. skip it here and we'll emit a better error later
 		}
-		rs = ldr.ResolveABIAlias(rs)
 		if ldr.SymValue(rs) == 0 && (ldr.SymType(rs) != sym.SDYNIMPORT && ldr.SymType(rs) != sym.SUNDEFEXT) {
 			if ldr.SymPkg(s) != "" && ldr.SymPkg(rs) == ldr.SymPkg(s) {
 				// Symbols in the same package are laid out together.
@@ -194,7 +193,6 @@ func (st *relocSymState) relocsym(s loader.Sym, P []byte) {
 		off := r.Off()
 		siz := int32(r.Siz())
 		rs := r.Sym()
-		rs = ldr.ResolveABIAlias(rs)
 		rt := r.Type()
 		weak := r.Weak()
 		if off < 0 || off+siz > int32(len(P)) {
@@ -340,7 +338,6 @@ func (st *relocSymState) relocsym(s loader.Sym, P []byte) {
 			if weak && !ldr.AttrReachable(rs) {
 				// Redirect it to runtime.unreachableMethod, which will throw if called.
 				rs = syms.unreachableMethod
-				rs = ldr.ResolveABIAlias(rs)
 			}
 			if target.IsExternal() {
 				nExtReloc++
@@ -614,7 +611,7 @@ func extreloc(ctxt *Link, ldr *loader.Loader, s loader.Sym, r loader.Reloc) (loa
 
 	case objabi.R_TLS_LE, objabi.R_TLS_IE:
 		if target.IsElf() {
-			rs := ldr.ResolveABIAlias(r.Sym())
+			rs := r.Sym()
 			rr.Xsym = rs
 			if rr.Xsym == 0 {
 				rr.Xsym = ctxt.Tlsg
@@ -626,10 +623,9 @@ func extreloc(ctxt *Link, ldr *loader.Loader, s loader.Sym, r loader.Reloc) (loa
 
 	case objabi.R_ADDR:
 		// set up addend for eventual relocation via outer symbol.
-		rs := ldr.ResolveABIAlias(r.Sym())
+		rs := r.Sym()
 		if r.Weak() && !ldr.AttrReachable(rs) {
 			rs = ctxt.ArchSyms.unreachableMethod
-			rs = ldr.ResolveABIAlias(rs)
 		}
 		rs, off := FoldSubSymbolOffset(ldr, rs)
 		rr.Xadd = r.Add() + off
@@ -644,13 +640,13 @@ func extreloc(ctxt *Link, ldr *loader.Loader, s loader.Sym, r loader.Reloc) (loa
 		if target.IsDarwin() {
 			return rr, false
 		}
-		rs := ldr.ResolveABIAlias(r.Sym())
+		rs := r.Sym()
 		rr.Xsym = loader.Sym(ldr.SymSect(rs).Sym)
 		rr.Xadd = r.Add() + ldr.SymValue(rs) - int64(ldr.SymSect(rs).Vaddr)
 
 	// r.Sym() can be 0 when CALL $(constant) is transformed from absolute PC to relative PC call.
 	case objabi.R_GOTPCREL, objabi.R_CALL, objabi.R_PCREL:
-		rs := ldr.ResolveABIAlias(r.Sym())
+		rs := r.Sym()
 		if rt == objabi.R_GOTPCREL && target.IsDynlinkingGo() && target.IsDarwin() && rs != 0 {
 			rr.Xadd = r.Add()
 			rr.Xadd -= int64(siz) // relative to address after the relocated chunk
@@ -692,7 +688,7 @@ func extreloc(ctxt *Link, ldr *loader.Loader, s loader.Sym, r loader.Reloc) (loa
 // symbol and addend.
 func ExtrelocSimple(ldr *loader.Loader, r loader.Reloc) loader.ExtReloc {
 	var rr loader.ExtReloc
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 	rr.Xsym = rs
 	rr.Xadd = r.Add()
 	rr.Type = r.Type()
@@ -705,7 +701,7 @@ func ExtrelocSimple(ldr *loader.Loader, r loader.Reloc) loader.ExtReloc {
 func ExtrelocViaOuterSym(ldr *loader.Loader, r loader.Reloc, s loader.Sym) loader.ExtReloc {
 	// set up addend for eventual relocation via outer symbol.
 	var rr loader.ExtReloc
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 	rs, off := FoldSubSymbolOffset(ldr, rs)
 	rr.Xadd = r.Add() + off
 	rst := ldr.SymType(rs)

diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
@@ -2471,7 +2471,7 @@ func (ctxt *Link) callgraph() {
 			if rs == 0 {
 				continue
 			}
-			if r.Type().IsDirectCall() && (ldr.SymType(rs) == sym.STEXT || ldr.SymType(rs) == sym.SABIALIAS) {
+			if r.Type().IsDirectCall() && ldr.SymType(rs) == sym.STEXT {
 				ctxt.Logf("%s calls %s\n", ldr.SymName(s), ldr.SymName(rs))
 			}
 		}

diff --git a/src/cmd/link/internal/ld/pe.go b/src/cmd/link/internal/ld/pe.go
@@ -1514,7 +1514,6 @@ func addPEBaseRelocSym(ldr *loader.Loader, s loader.Sym, rt *peBaseRelocTable) {
 			continue
 		}
 		rs := r.Sym()
-		rs = ldr.ResolveABIAlias(rs)
 		if rs == 0 {
 			continue
 		}

diff --git a/src/cmd/link/internal/ld/xcoff.go b/src/cmd/link/internal/ld/xcoff.go
@@ -1238,7 +1238,7 @@ func Xcoffadddynrel(target *Target, ldr *loader.Loader, syms *ArchSyms, s loader
 		sym:  s,
 		roff: r.Off(),
 	}
-	targ := ldr.ResolveABIAlias(r.Sym())
+	targ := r.Sym()
 	var targType sym.SymKind
 	if targ != 0 {
 		targType = ldr.SymType(targ)
@@ -1333,7 +1333,7 @@ func (ctxt *Link) doxcoff() {
 				panic("cgo_export on static symbol")
 			}
 
-			if ldr.SymType(s) == sym.STEXT || ldr.SymType(s) == sym.SABIALIAS {
+			if ldr.SymType(s) == sym.STEXT {
 				// On AIX, a exported function must have two symbols:
 				// - a .text symbol which must start with a ".".
 				// - a .data symbol which is a function descriptor.

diff --git a/src/cmd/link/internal/loader/loader.go b/src/cmd/link/internal/loader/loader.go
@@ -307,7 +307,6 @@ type extSymPayload struct {
 const (
 	// Loader.flags
 	FlagStrictDups = 1 << iota
-	FlagUseABIAlias
 )
 
 func NewLoader(flags uint32, elfsetstring elfsetstringFunc, reporter *ErrorReporter) *Loader {
@@ -2297,27 +2296,6 @@ func abiToVer(abi uint16, localSymVersion int) int {
 	return v
 }
 
-// ResolveABIAlias given a symbol returns the ABI alias target of that
-// symbol. If the sym in question is not an alias, the sym itself is
-// returned.
-func (l *Loader) ResolveABIAlias(s Sym) Sym {
-	if l.flags&FlagUseABIAlias == 0 {
-		return s
-	}
-	if s == 0 {
-		return 0
-	}
-	if l.SymType(s) != sym.SABIALIAS {
-		return s
-	}
-	relocs := l.Relocs(s)
-	target := relocs.At(0).Sym()
-	if l.SymType(target) == sym.SABIALIAS {
-		panic(fmt.Sprintf("ABI alias %s references another ABI alias %s", l.SymName(s), l.SymName(target)))
-	}
-	return target
-}
-
 // TopLevelSym tests a symbol (by name and kind) to determine whether
 // the symbol first class sym (participating in the link) or is an
 // anonymous aux or sub-symbol containing some sub-part or payload of

diff --git a/src/cmd/link/internal/mips/asm.go b/src/cmd/link/internal/mips/asm.go
@@ -92,7 +92,6 @@ func applyrel(arch *sys.Arch, ldr *loader.Loader, rt objabi.RelocType, off int32
 
 func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) (o int64, nExtReloc int, ok bool) {
 	rs := r.Sym()
-	rs = ldr.ResolveABIAlias(rs)
 	if target.IsExternal() {
 		switch r.Type() {
 		default:

diff --git a/src/cmd/link/internal/mips64/asm.go b/src/cmd/link/internal/mips64/asm.go
@@ -120,7 +120,6 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade
 	const isOk = true
 	const noExtReloc = 0
 	rs := r.Sym()
-	rs = ldr.ResolveABIAlias(rs)
 	switch r.Type() {
 	case objabi.R_ADDRMIPS,
 		objabi.R_ADDRMIPSU:

diff --git a/src/cmd/link/internal/ppc64/asm.go b/src/cmd/link/internal/ppc64/asm.go
@@ -547,7 +547,7 @@ func symtoc(ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym) int64 {
 // symbol address can be used directly.
 // This code is for AIX only.
 func archreloctoc(ldr *loader.Loader, target *ld.Target, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) int64 {
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 	if target.IsLinux() {
 		ldr.Errorf(s, "archrelocaddr called for %s relocation\n", ldr.SymName(rs))
 	}
@@ -562,7 +562,7 @@ func archreloctoc(ldr *loader.Loader, target *ld.Target, syms *ld.ArchSyms, r lo
 	var t int64
 	useAddi := false
 	relocs := ldr.Relocs(rs)
-	tarSym := ldr.ResolveABIAlias(relocs.At(0).Sym())
+	tarSym := relocs.At(0).Sym()
 
 	if target.IsInternal() && tarSym != 0 && ldr.AttrReachable(tarSym) && ldr.SymSect(tarSym).Seg == &ld.Segdata {
 		t = ldr.SymValue(tarSym) + r.Add() - ldr.SymValue(syms.TOC)
@@ -603,7 +603,7 @@ func archreloctoc(ldr *loader.Loader, target *ld.Target, syms *ld.ArchSyms, r lo
 // archrelocaddr relocates a symbol address.
 // This code is for AIX only.
 func archrelocaddr(ldr *loader.Loader, target *ld.Target, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) int64 {
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 	if target.IsAIX() {
 		ldr.Errorf(s, "archrelocaddr called for %s relocation\n", ldr.SymName(rs))
 	}
@@ -802,7 +802,7 @@ func gentramp(ctxt *ld.Link, ldr *loader.Loader, tramp *loader.SymbolBuilder, ta
 }
 
 func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) (relocatedOffset int64, nExtReloc int, ok bool) {
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 	if target.IsExternal() {
 		// On AIX, relocations (except TLS ones) must be also done to the
 		// value with the current addresses.
@@ -909,7 +909,7 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade
 }
 
 func archrelocvariant(target *ld.Target, ldr *loader.Loader, r loader.Reloc, rv sym.RelocVariant, s loader.Sym, t int64, p []byte) (relocatedOffset int64) {
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 	switch rv & sym.RV_TYPE_MASK {
 	default:
 		ldr.Errorf(s, "unexpected relocation variant %d", rv)

diff --git a/src/cmd/link/internal/riscv64/asm.go b/src/cmd/link/internal/riscv64/asm.go
@@ -168,7 +168,7 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade
 		return val, 0, false
 	}
 
-	rs := ldr.ResolveABIAlias(r.Sym())
+	rs := r.Sym()
 
 	switch r.Type() {
 	case objabi.R_CALLRISCV:

diff --git a/src/cmd/link/internal/sym/symkind.go b/src/cmd/link/internal/sym/symkind.go
@@ -118,9 +118,6 @@ const (
 	SDWARFRANGE
 	SDWARFLOC
 	SDWARFLINES
-
-	// ABI aliases (these never appear in the output)
-	SABIALIAS
 )
 
 // AbiSymKindToSymKind maps values read from object files (which are
@@ -143,7 +140,6 @@ var AbiSymKindToSymKind = [...]SymKind{
 	SDWARFRANGE,
 	SDWARFLOC,
 	SDWARFLINES,
-	SABIALIAS,
 	SLIBFUZZER_EXTRA_COUNTER,
 }
 

diff --git a/src/cmd/link/internal/sym/symkind_string.go b/src/cmd/link/internal/sym/symkind_string.go
diff --git a/src/cmd/link/internal/wasm/asm.go b/src/cmd/link/internal/wasm/asm.go
@@ -173,7 +173,7 @@ func asmb2(ctxt *ld.Link, ldr *loader.Loader) {
 				}
 				wfn.Write(P[off:r.Off()])
 				off = r.Off()
-				rs := ldr.ResolveABIAlias(r.Sym())
+				rs := r.Sym()
 				switch r.Type() {
 				case objabi.R_ADDR:
 					writeSleb128(wfn, ldr.SymValue(rs)+r.Add())