cmd/link/internal/ld: simple cleanups

Simplify some C-style loops with range statements, and move some
declarations closer to their uses.

While at it, ensure that all the SymbolType consts are typed.

Change-Id: I04b06afb2c1fb249ef8093a0c5cca0a597d1e05c
Reviewed-on: https://go-review.googlesource.com/105217
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 74faa7f8b291bf2d7f65de4d7104a36ed857b29e..77acfaf7b97c0ad3cfad87174cf6375d17163d71 100644 (file)
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -504,7 +504,7 @@ func windynrelocsym(ctxt *Link, s *sym.Symbol) {
        if s == rel {
                return
        }
-       for ri := 0; ri < len(s.R); ri++ {
+       for ri := range s.R {
                r := &s.R[ri]
                targ := r.Sym
                if targ == nil {
@@ -550,7 +550,7 @@ func dynrelocsym(ctxt *Link, s *sym.Symbol) {
                return
        }
 
-       for ri := 0; ri < len(s.R); ri++ {
+       for ri := range s.R {
                r := &s.R[ri]
                if ctxt.BuildMode == BuildModePIE && ctxt.LinkMode == LinkInternal {
                        // It's expected that some relocations will be done
@@ -620,7 +620,6 @@ func CodeblkPad(ctxt *Link, addr int64, size int64, pad []byte) {
        }
 
        eaddr := addr + size
-       var q []byte
        for _, s := range syms {
                if !s.Attr.Reachable() {
                        continue
@@ -638,7 +637,7 @@ func CodeblkPad(ctxt *Link, addr int64, size int64, pad []byte) {
                }
 
                ctxt.Logf("%.6x\t%-20s\n", uint64(addr), s.Name)
-               q = s.P
+               q := s.P
 
                for len(q) >= 16 {
                        ctxt.Logf("%.6x\t% x\n", uint64(addr), q[:16])
@@ -1195,7 +1194,6 @@ func (ctxt *Link) dodata() {
                sect.Align = dataMaxAlign[sym.SELFGOT]
                datsize = Rnd(datsize, int64(sect.Align))
                sect.Vaddr = uint64(datsize)
-               var toc *sym.Symbol
                for _, s := range data[sym.SELFGOT] {
                        datsize = aligndatsize(datsize, s)
                        s.Sect = sect
@@ -1203,7 +1201,7 @@ func (ctxt *Link) dodata() {
                        s.Value = int64(uint64(datsize) - sect.Vaddr)
 
                        // Resolve .TOC. symbol for this object file (ppc64)
-                       toc = ctxt.Syms.ROLookup(".TOC.", int(s.Version))
+                       toc := ctxt.Syms.ROLookup(".TOC.", int(s.Version))
                        if toc != nil {
                                toc.Sect = sect
                                toc.Outer = s

diff --git a/src/cmd/link/internal/ld/deadcode.go b/src/cmd/link/internal/ld/deadcode.go
index c5c48e5c854c737150c22392c3c7600ea3ebe208..ce0fe1f7a132913bf8d8019893e117e00368da84 100644 (file)
--- a/src/cmd/link/internal/ld/deadcode.go
+++ b/src/cmd/link/internal/ld/deadcode.go
@@ -295,7 +295,7 @@ func (d *deadcodepass) flood() {
 
                mpos := 0 // 0-3, the R_METHODOFF relocs of runtime.uncommontype
                var methods []methodref
-               for i := 0; i < len(s.R); i++ {
+               for i := range s.R {
                        r := &s.R[i]
                        if r.Sym == nil {
                                continue

diff --git a/src/cmd/link/internal/ld/dwarf.go b/src/cmd/link/internal/ld/dwarf.go
index f18d13e910f2d0a7e07fdf7feb33054a5f8ba74f..c90609feef1e909f9c5da810cb46c8b206dcb574 100644 (file)
--- a/src/cmd/link/internal/ld/dwarf.go
+++ b/src/cmd/link/internal/ld/dwarf.go
@@ -463,11 +463,9 @@ func newtype(ctxt *Link, gotype *sym.Symbol) *dwarf.DWDie {
                dotypedef(ctxt, &dwtypes, name, die)
                newrefattr(die, dwarf.DW_AT_type, mustFind(ctxt, "void"))
                nfields := decodetypeFuncInCount(ctxt.Arch, gotype)
-               var fld *dwarf.DWDie
-               var s *sym.Symbol
                for i := 0; i < nfields; i++ {
-                       s = decodetypeFuncInType(ctxt.Arch, gotype, i)
-                       fld = newdie(ctxt, die, dwarf.DW_ABRV_FUNCTYPEPARAM, s.Name[5:], 0)
+                       s := decodetypeFuncInType(ctxt.Arch, gotype, i)
+                       fld := newdie(ctxt, die, dwarf.DW_ABRV_FUNCTYPEPARAM, s.Name[5:], 0)
                        newrefattr(fld, dwarf.DW_AT_type, defgotype(ctxt, s))
                }
 
@@ -476,8 +474,8 @@ func newtype(ctxt *Link, gotype *sym.Symbol) *dwarf.DWDie {
                }
                nfields = decodetypeFuncOutCount(ctxt.Arch, gotype)
                for i := 0; i < nfields; i++ {
-                       s = decodetypeFuncOutType(ctxt.Arch, gotype, i)
-                       fld = newdie(ctxt, die, dwarf.DW_ABRV_FUNCTYPEPARAM, s.Name[5:], 0)
+                       s := decodetypeFuncOutType(ctxt.Arch, gotype, i)
+                       fld := newdie(ctxt, die, dwarf.DW_ABRV_FUNCTYPEPARAM, s.Name[5:], 0)
                        newrefattr(fld, dwarf.DW_AT_type, defptrto(ctxt, defgotype(ctxt, s)))
                }
 
@@ -667,15 +665,10 @@ func synthesizeslicetypes(ctxt *Link, die *dwarf.DWDie) {
 }
 
 func mkinternaltypename(base string, arg1 string, arg2 string) string {
-       var buf string
-
        if arg2 == "" {
-               buf = fmt.Sprintf("%s<%s>", base, arg1)
-       } else {
-               buf = fmt.Sprintf("%s<%s,%s>", base, arg1, arg2)
+               return fmt.Sprintf("%s<%s>", base, arg1)
        }
-       n := buf
-       return n
+       return fmt.Sprintf("%s<%s,%s>", base, arg1, arg2)
 }
 
 // synthesizemaptypes is way too closely married to runtime/hashmap.c
@@ -1208,7 +1201,7 @@ func writelines(ctxt *Link, lib *sym.Library, textp []*sym.Symbol, ls *sym.Symbo
                // example, files mentioned only in an inlined subroutine).
                dsym := ctxt.Syms.Lookup(dwarf.InfoPrefix+s.Name, int(s.Version))
                importInfoSymbol(ctxt, dsym)
-               for ri := 0; ri < len(dsym.R); ri++ {
+               for ri := range dsym.R {
                        r := &dsym.R[ri]
                        if r.Type != objabi.R_DWARFFILEREF {
                                continue
@@ -1321,9 +1314,8 @@ func writelines(ctxt *Link, lib *sym.Library, textp []*sym.Symbol, ls *sym.Symbo
        // DIE flavors (ex: variables) then those DIEs would need to
        // be included below.
        missing := make(map[int]interface{})
-       for fidx := 0; fidx < len(funcs); fidx++ {
-               f := funcs[fidx]
-               for ri := 0; ri < len(f.R); ri++ {
+       for _, f := range funcs {
+               for ri := range f.R {
                        r := &f.R[ri]
                        if r.Type != objabi.R_DWARFFILEREF {
                                continue

diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go
index 231c00d3c1592fd0360e8b907a14abfc2d77f546..60d387c19313f57f483b9b31cc06fd8c0661be42 100644 (file)
--- a/src/cmd/link/internal/ld/elf.go
+++ b/src/cmd/link/internal/ld/elf.go
@@ -1349,7 +1349,7 @@ func elfrelocsect(ctxt *Link, sect *sym.Section, syms []*sym.Symbol) {
                if s.Value >= int64(eaddr) {
                        break
                }
-               for ri := 0; ri < len(s.R); ri++ {
+               for ri := range s.R {
                        r := &s.R[ri]
                        if r.Done {
                                continue

diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index a27f29af46afe48a5a861e6560c9d1ea94cfbae9..1909aad918e16716f942cc8f827481b06c92aaf6 100644 (file)
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -275,9 +275,9 @@ func loadinternal(ctxt *Link, name string) *sym.Library {
                return nil
        }
 
-       for i := 0; i < len(ctxt.Libdir); i++ {
+       for _, libdir := range ctxt.Libdir {
                if ctxt.linkShared {
-                       shlibname := filepath.Join(ctxt.Libdir[i], name+".shlibname")
+                       shlibname := filepath.Join(libdir, name+".shlibname")
                        if ctxt.Debugvlog != 0 {
                                ctxt.Logf("searching for %s.a in %s\n", name, shlibname)
                        }
@@ -285,7 +285,7 @@ func loadinternal(ctxt *Link, name string) *sym.Library {
                                return addlibpath(ctxt, "internal", "internal", "", name, shlibname)
                        }
                }
-               pname := filepath.Join(ctxt.Libdir[i], name+".a")
+               pname := filepath.Join(libdir, name+".a")
                if ctxt.Debugvlog != 0 {
                        ctxt.Logf("searching for %s.a in %s\n", name, pname)
                }
@@ -484,7 +484,7 @@ func (ctxt *Link) loadlib() {
                x = sym.AttrCgoExportStatic
        }
        w := 0
-       for i := 0; i < len(dynexp); i++ {
+       for i := range dynexp {
                if dynexp[i].Attr&x != 0 {
                        dynexp[w] = dynexp[i]
                        w++
@@ -868,8 +868,8 @@ var internalpkg = []string{
 
 func ldhostobj(ld func(*Link, *bio.Reader, string, int64, string), headType objabi.HeadType, f *bio.Reader, pkg string, length int64, pn string, file string) *Hostobj {
        isinternal := false
-       for i := 0; i < len(internalpkg); i++ {
-               if pkg == internalpkg[i] {
+       for _, intpkg := range internalpkg {
+               if pkg == intpkg {
                        isinternal = true
                        break
                }
@@ -1955,22 +1955,18 @@ func usage() {
        Exit(2)
 }
 
-func doversion() {
-       Exitf("version %s", objabi.Version)
-}
-
 type SymbolType int8
 
 const (
        // see also http://9p.io/magic/man2html/1/nm
        TextSym      SymbolType = 'T'
-       DataSym                 = 'D'
-       BSSSym                  = 'B'
-       UndefinedSym            = 'U'
-       TLSSym                  = 't'
-       FrameSym                = 'm'
-       ParamSym                = 'p'
-       AutoSym                 = 'a'
+       DataSym      SymbolType = 'D'
+       BSSSym       SymbolType = 'B'
+       UndefinedSym SymbolType = 'U'
+       TLSSym       SymbolType = 't'
+       FrameSym     SymbolType = 'm'
+       ParamSym     SymbolType = 'p'
+       AutoSym      SymbolType = 'a'
 
        // Deleted auto (not a real sym, just placeholder for type)
        DeletedAutoSym = 'x'
@@ -2256,7 +2252,7 @@ func bgetc(r *bio.Reader) int {
 
 type markKind uint8 // for postorder traversal
 const (
-       unvisited markKind = iota
+       _ markKind = iota
        visiting
        visited
 )

diff --git a/src/cmd/link/internal/ld/macho.go b/src/cmd/link/internal/ld/macho.go
index db933a6767f062518314fcac229928eb1119d5d9..8643fef043cae90e507dbf117174487aa58c064d 100644 (file)
--- a/src/cmd/link/internal/ld/macho.go
+++ b/src/cmd/link/internal/ld/macho.go
@@ -234,7 +234,7 @@ func machowrite(arch *sys.Arch, out *OutBuf, linkmode LinkMode) int {
        o1 := out.Offset()
 
        loadsize := 4 * 4 * ndebug
-       for i := 0; i < len(load); i++ {
+       for i := range load {
                loadsize += 4 * (len(load[i].data) + 2)
        }
        if arch.PtrSize == 8 {
@@ -327,7 +327,7 @@ func machowrite(arch *sys.Arch, out *OutBuf, linkmode LinkMode) int {
                }
        }
 
-       for i := 0; i < len(load); i++ {
+       for i := range load {
                l := &load[i]
                out.Write32(l.type_)
                out.Write32(4 * (uint32(len(l.data)) + 2))
@@ -621,13 +621,13 @@ func Asmbmacho(ctxt *Link) {
                        ml.data[0] = 12 /* offset to string */
                        stringtouint32(ml.data[1:], "/usr/lib/dyld")
 
-                       for i := 0; i < len(dylib); i++ {
-                               ml = newMachoLoad(ctxt.Arch, LC_LOAD_DYLIB, 4+(uint32(len(dylib[i]))+1+7)/8*2)
+                       for _, lib := range dylib {
+                               ml = newMachoLoad(ctxt.Arch, LC_LOAD_DYLIB, 4+(uint32(len(lib))+1+7)/8*2)
                                ml.data[0] = 24 /* offset of string from beginning of load */
                                ml.data[1] = 0  /* time stamp */
                                ml.data[2] = 0  /* version */
                                ml.data[3] = 0  /* compatibility version */
-                               stringtouint32(ml.data[4:], dylib[i])
+                               stringtouint32(ml.data[4:], lib)
                        }
                }
        }
@@ -721,7 +721,7 @@ func machosymorder(ctxt *Link) {
        // On Mac OS X Mountain Lion, we must sort exported symbols
        // So we sort them here and pre-allocate dynid for them
        // See https://golang.org/issue/4029
-       for i := 0; i < len(dynexp); i++ {
+       for i := range dynexp {
                dynexp[i].Attr |= sym.AttrReachable
        }
        machogenasmsym(ctxt)
@@ -919,7 +919,7 @@ func machorelocsect(ctxt *Link, sect *sym.Section, syms []*sym.Symbol) {
                if s.Value >= int64(eaddr) {
                        break
                }
-               for ri := 0; ri < len(s.R); ri++ {
+               for ri := range s.R {
                        r := &s.R[ri]
                        if r.Done {
                                continue

diff --git a/src/cmd/link/internal/ld/pcln.go b/src/cmd/link/internal/ld/pcln.go
index 8708924d92a2709b5b18f17e6e08859b106bf5d9..446f64bdbc6ec3b4fe5484724729ac18c694ee4d 100644 (file)
--- a/src/cmd/link/internal/ld/pcln.go
+++ b/src/cmd/link/internal/ld/pcln.go
@@ -122,11 +122,8 @@ func numberfile(ctxt *Link, file *sym.Symbol) {
 }
 
 func renumberfiles(ctxt *Link, files []*sym.Symbol, d *sym.Pcdata) {
-       var f *sym.Symbol
-
        // Give files numbers.
-       for i := 0; i < len(files); i++ {
-               f = files[i]
+       for _, f := range files {
                numberfile(ctxt, f)
        }
 
@@ -399,7 +396,7 @@ func (ctxt *Link) pclntab() {
                off = addpctab(ctxt, ftab, off, &pcln.Pcline)
                off = int32(ftab.SetUint32(ctxt.Arch, int64(off), uint32(len(pcln.Pcdata))))
                off = int32(ftab.SetUint32(ctxt.Arch, int64(off), uint32(len(pcln.Funcdata))))
-               for i := 0; i < len(pcln.Pcdata); i++ {
+               for i := range pcln.Pcdata {
                        off = addpctab(ctxt, ftab, off, &pcln.Pcdata[i])
                }
 
@@ -409,7 +406,7 @@ func (ctxt *Link) pclntab() {
                        if off&int32(ctxt.Arch.PtrSize-1) != 0 {
                                off += 4
                        }
-                       for i := 0; i < len(pcln.Funcdata); i++ {
+                       for i := range pcln.Funcdata {
                                if pcln.Funcdata[i] == nil {
                                        ftab.SetUint(ctxt.Arch, int64(off)+int64(ctxt.Arch.PtrSize)*int64(i), uint64(pcln.Funcdataoff[i]))
                                } else {

diff --git a/src/cmd/link/internal/ld/pe.go b/src/cmd/link/internal/ld/pe.go
index d07f201557ec17761dea8dd8cf39d01739b72a1c..66b1463086d730ed4c4cb8506269417c3ba40179 100644 (file)
--- a/src/cmd/link/internal/ld/pe.go
+++ b/src/cmd/link/internal/ld/pe.go
@@ -526,7 +526,7 @@ func (f *peFile) emitRelocations(ctxt *Link) {
                        if sym.Value >= int64(eaddr) {
                                break
                        }
-                       for ri := 0; ri < len(sym.R); ri++ {
+                       for ri := range sym.R {
                                r := &sym.R[ri]
                                if r.Done {
                                        continue
@@ -1082,9 +1082,8 @@ func addimports(ctxt *Link, datsect *peSection) {
        }
 
        // write function names
-       var m *Imp
        for d := dr; d != nil; d = d.next {
-               for m = d.ms; m != nil; m = m.next {
+               for m := d.ms; m != nil; m = m.next {
                        m.off = uint64(pefile.nextSectOffset) + uint64(ctxt.Out.Offset()) - uint64(startoff)
                        ctxt.Out.Write16(0) // hint
                        strput(ctxt.Out, m.s.Extname)
@@ -1097,7 +1096,7 @@ func addimports(ctxt *Link, datsect *peSection) {
        n = uint64(ctxt.Out.Offset())
        for d := dr; d != nil; d = d.next {
                d.thunkoff = uint64(ctxt.Out.Offset()) - n
-               for m = d.ms; m != nil; m = m.next {
+               for m := d.ms; m != nil; m = m.next {
                        if pe64 != 0 {
                                ctxt.Out.Write64(m.off)
                        } else {
@@ -1126,7 +1125,7 @@ func addimports(ctxt *Link, datsect *peSection) {
 
        ctxt.Out.SeekSet(int64(uint64(datsect.pointerToRawData) + ftbase))
        for d := dr; d != nil; d = d.next {
-               for m = d.ms; m != nil; m = m.next {
+               for m := d.ms; m != nil; m = m.next {
                        if pe64 != 0 {
                                ctxt.Out.Write64(m.off)
                        } else {
@@ -1287,13 +1286,10 @@ func addpersrc(ctxt *Link) {
        h.checkOffset(ctxt.Out.Offset())
 
        // relocation
-       var p []byte
-       var r *sym.Reloc
-       var val uint32
-       for ri := 0; ri < len(rsrcsym.R); ri++ {
-               r = &rsrcsym.R[ri]
-               p = rsrcsym.P[r.Off:]
-               val = uint32(int64(h.virtualAddress) + r.Add)
+       for ri := range rsrcsym.R {
+               r := &rsrcsym.R[ri]
+               p := rsrcsym.P[r.Off:]
+               val := uint32(int64(h.virtualAddress) + r.Add)
 
                // 32-bit little-endian
                p[0] = byte(val)