cmd: remove unused code

Generated with honnef.co/go/unused

There is a large amount of unused code in cmd/internal/obj/s390x but
that can wait til the s390x port is merged.

There is some unused code in
cmd/internal/unvendor/golang.org/x/arch/arm/armasm but that should be
addressed upstream and a new revision imported.

Change-Id: I252c0f9ea8c5bb1a0b530a374ef13a0a20ea56aa
Reviewed-on: https://go-review.googlesource.com/21782
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>

src/cmd/internal/goobj/read.go

@@ -229,11 +229,8 @@ var (
 
 	errCorruptArchive   = errors.New("corrupt archive")
 	errTruncatedArchive = errors.New("truncated archive")
-	errNotArchive       = errors.New("unrecognized archive format")
-
-	errCorruptObject   = errors.New("corrupt object file")
-	errTruncatedObject = errors.New("truncated object file")
-	errNotObject       = errors.New("unrecognized object file format")
+	errCorruptObject    = errors.New("corrupt object file")
+	errNotObject        = errors.New("unrecognized object file format")
 )
 
 // An objReader is an object file reader.

src/cmd/internal/obj/mips/asm0.go

@@ -974,10 +974,6 @@ func OP_JMP(op uint32, i uint32) uint32 {
 	return op | i&0x3FFFFFF
 }
 
-func oclass(a *obj.Addr) int {
-	return int(a.Class) - 1
-}
-
 func asmout(ctxt *obj.Link, p *obj.Prog, o *Optab, out []uint32) {
 	o1 := uint32(0)
 	o2 := uint32(0)

src/cmd/internal/obj/x86/asm6.go

@@ -884,11 +884,6 @@ var yvex_vpbroadcast = []ytab{
 	{Yxm, Ynone, Yyr, Zvex_rm_v_r, 2},
 }
 
-var yvex_xxmyxm = []ytab{
-	{Yxr, Ynone, Yxm, Zvex_r_v_rm, 2},
-	{Yyr, Ynone, Yxm, Zvex_r_v_rm, 2},
-}
-
 var ymmxmm0f38 = []ytab{
 	{Ymm, Ynone, Ymr, Zlitm_r, 3},
 	{Yxm, Ynone, Yxr, Zlitm_r, 5},

src/cmd/internal/obj/x86/obj6_test.go

@@ -76,7 +76,6 @@ func parseTestData(t *testing.T) *ParsedTestData {
 }
 
 var spaces_re *regexp.Regexp = regexp.MustCompile("\\s+")
-var marker_re *regexp.Regexp = regexp.MustCompile("MOVQ \\$([0-9]+), AX")
 
 func normalize(s string) string {
 	return spaces_re.ReplaceAllLiteralString(strings.TrimSpace(s), " ")

src/cmd/internal/objfile/pe.go

@@ -69,8 +69,6 @@ func (f *peFile) symbols() ([]Sym, error) {
 				text  = 0x20
 				data  = 0x40
 				bss   = 0x80
-				permX = 0x20000000
-				permR = 0x40000000
 				permW = 0x80000000
 			)
 			ch := sect.Characteristics

src/cmd/link/internal/amd64/asm.go

@@ -99,12 +99,6 @@ func gentext() {
 	ld.Addaddr(ld.Ctxt, initarray_entry, initfunc)
 }
 
-func adddynrela(rela *ld.LSym, s *ld.LSym, r *ld.Reloc) {
-	ld.Addaddrplus(ld.Ctxt, rela, s, int64(r.Off))
-	ld.Adduint64(ld.Ctxt, rela, ld.R_X86_64_RELATIVE)
-	ld.Addaddrplus(ld.Ctxt, rela, r.Sym, r.Add) // Addend
-}
-
 func adddynrel(s *ld.LSym, r *ld.Reloc) {
 	targ := r.Sym
 	ld.Ctxt.Cursym = s

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

@@ -114,11 +114,6 @@ func braddoff(a int32, b int32) int32 {
 	return int32((uint32(a))&0xff000000 | 0x00ffffff&uint32(a+b))
 }
 
-func adddynrela(rel *ld.LSym, s *ld.LSym, r *ld.Reloc) {
-	ld.Addaddrplus(ld.Ctxt, rel, s, int64(r.Off))
-	ld.Adduint32(ld.Ctxt, rel, ld.R_ARM_RELATIVE)
-}
-
 func adddynrel(s *ld.LSym, r *ld.Reloc) {
 	targ := r.Sym
 	ld.Ctxt.Cursym = s

src/cmd/link/internal/arm64/asm.go

@@ -91,10 +91,6 @@ func gentext() {
 	ld.Addaddr(ld.Ctxt, initarray_entry, initfunc)
 }
 
-func adddynrela(rel *ld.LSym, s *ld.LSym, r *ld.Reloc) {
-	log.Fatalf("adddynrela not implemented")
-}
-
 func adddynrel(s *ld.LSym, r *ld.Reloc) {
 	log.Fatalf("adddynrel not implemented")
 }

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

@@ -236,10 +236,6 @@ func addaddrplus4(ctxt *Link, s *LSym, t *LSym, add int64) int64 {
  * Used for the data block.
  */
 
-func listnextp(s *LSym) **LSym {
-	return &s.Next
-}
-
 func listsubp(s *LSym) **LSym {
 	return &s.Sub
 }

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

@@ -170,9 +170,7 @@ type methodref struct {
 	r   [3]*Reloc // R_METHOD relocations to fields of runtime.method
 }
 
-func (m methodref) mtyp() *LSym { return m.r[0].Sym }
-func (m methodref) ifn() *LSym  { return m.r[1].Sym }
-func (m methodref) tfn() *LSym  { return m.r[2].Sym }
+func (m methodref) ifn() *LSym { return m.r[1].Sym }
 
 func (m methodref) isExported() bool {
 	for _, r := range m.m {

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

@@ -56,11 +56,6 @@ func decodetype_kind(s *LSym) uint8 {
 	return uint8(s.P[2*SysArch.PtrSize+7] & obj.KindMask) //  0x13 / 0x1f
 }
 
-// Type.commonType.kind
-func decodetype_noptr(s *LSym) uint8 {
-	return uint8(s.P[2*SysArch.PtrSize+7] & obj.KindNoPointers) //  0x13 / 0x1f
-}
-
 // Type.commonType.kind
 func decodetype_usegcprog(s *LSym) uint8 {
 	return uint8(s.P[2*SysArch.PtrSize+7] & obj.KindGCProg) //  0x13 / 0x1f
@@ -216,19 +211,6 @@ func decodetype_structfieldarrayoff(s *LSym, i int) int {
 	return off
 }
 
-func decodetype_stringptr(s *LSym, off int) string {
-	s = decode_reloc_sym(s, int32(off))
-	if s == nil {
-		return ""
-	}
-	r := decode_reloc(s, 0) // s has a pointer to the string data at offset 0
-	if r == nil {           // shouldn't happen.
-		return ""
-	}
-	strlen := int64(decode_inuxi(s.P[SysArch.PtrSize:], SysArch.IntSize))
-	return string(r.Sym.P[r.Add : r.Add+strlen])
-}
-
 // decodetype_name decodes the name from a reflect.name.
 func decodetype_name(s *LSym, off int) string {
 	r := decode_reloc(s, int32(off))

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

@@ -419,35 +419,7 @@ type Pkg struct {
 	impby   []*Pkg
 }
 
-var (
-	// pkgmap records the imported-by relationship between packages.
-	// Entries are keyed by package path (e.g., "runtime" or "net/url").
-	pkgmap = map[string]*Pkg{}
-
-	pkgall []*Pkg
-)
-
-func lookupPkg(path string) *Pkg {
-	if p, ok := pkgmap[path]; ok {
-		return p
-	}
-	p := &Pkg{path: path}
-	pkgmap[path] = p
-	pkgall = append(pkgall, p)
-	return p
-}
-
-// imported records that package pkg imports package imp.
-func imported(pkg, imp string) {
-	// everyone imports runtime, even runtime.
-	if imp == "runtime" {
-		return
-	}
-
-	p := lookupPkg(pkg)
-	i := lookupPkg(imp)
-	i.impby = append(i.impby, p)
-}
+var pkgall []*Pkg
 
 func (p *Pkg) cycle() *Pkg {
 	if p.checked {

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

@@ -586,11 +586,8 @@ func Asmbmacho() {
 		// and we can assume OS X.
 		//
 		// See golang.org/issues/12941.
-		const (
-			LC_VERSION_MIN_MACOSX   = 0x24
-			LC_VERSION_MIN_IPHONEOS = 0x25
-			LC_VERSION_MIN_WATCHOS  = 0x30
-		)
+		const LC_VERSION_MIN_MACOSX = 0x24
+
 		ml := newMachoLoad(LC_VERSION_MIN_MACOSX, 2)
 		ml.data[0] = 10<<16 | 7<<8 | 0<<0 // OS X version 10.7.0
 		ml.data[1] = 10<<16 | 7<<8 | 0<<0 // SDK 10.7.0

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

@@ -15,11 +15,9 @@ import (
 	"unsafe"
 )
 
-var fakedwarf, realdwarf, linkseg *macho.Segment
+var realdwarf, linkseg *macho.Segment
 var dwarfstart, linkstart int64
 var linkoffset uint32
-var machHeader *macho.FileHeader
-var mappedHeader []byte
 
 const (
 	LC_ID_DYLIB             = 0xd

src/cmd/link/internal/mips64/asm.go

@@ -41,10 +41,6 @@ import (
 
 func gentext() {}
 
-func adddynrela(rel *ld.LSym, s *ld.LSym, r *ld.Reloc) {
-	log.Fatalf("adddynrela not implemented")
-}
-
 func adddynrel(s *ld.LSym, r *ld.Reloc) {
 	log.Fatalf("adddynrel not implemented")
 }

src/cmd/link/internal/ppc64/asm.go

@@ -265,10 +265,6 @@ func gencallstub(abicase int, stub *ld.LSym, targ *ld.LSym) {
 	ld.Adduint32(ld.Ctxt, stub, 0x4e800420) // bctr
 }
 
-func adddynrela(rel *ld.LSym, s *ld.LSym, r *ld.Reloc) {
-	log.Fatalf("adddynrela not implemented")
-}
-
 func adddynrel(s *ld.LSym, r *ld.Reloc) {
 	targ := r.Sym
 	ld.Ctxt.Cursym = s

src/cmd/link/internal/x86/asm.go

@@ -139,10 +139,6 @@ func gentext() {
 	ld.Addaddr(ld.Ctxt, initarray_entry, initfunc)
 }
 
-func adddynrela(rela *ld.LSym, s *ld.LSym, r *ld.Reloc) {
-	log.Fatalf("adddynrela not implemented")
-}
-
 func adddynrel(s *ld.LSym, r *ld.Reloc) {
 	targ := r.Sym
 	ld.Ctxt.Cursym = s