| // Copyright 2017 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package sym |
| |
| import ( |
| "cmd/internal/obj" |
| "cmd/internal/objabi" |
| "cmd/internal/sys" |
| "debug/elf" |
| "fmt" |
| "log" |
| ) |
| |
| // Symbol is an entry in the symbol table. |
| type Symbol struct { |
| Name string |
| Type SymKind |
| Version int16 |
| Attr Attribute |
| Dynid int32 |
| Align int32 |
| Elfsym int32 |
| LocalElfsym int32 |
| Value int64 |
| Size int64 |
| Sub *Symbol |
| Outer *Symbol |
| Gotype *Symbol |
| File string // actually package! |
| auxinfo *AuxSymbol |
| Sect *Section |
| FuncInfo *FuncInfo |
| Unit *CompilationUnit |
| // P contains the raw symbol data. |
| P []byte |
| R []Reloc |
| } |
| |
| // AuxSymbol contains less-frequently used sym.Symbol fields. |
| type AuxSymbol struct { |
| extname string |
| dynimplib string |
| dynimpvers string |
| localentry uint8 |
| plt int32 |
| got int32 |
| // ElfType is set for symbols read from shared libraries by ldshlibsyms. It |
| // is not set for symbols defined by the packages being linked or by symbols |
| // read by ldelf (and so is left as elf.STT_NOTYPE). |
| elftype elf.SymType |
| } |
| |
| const ( |
| SymVerABI0 = 0 |
| SymVerABIInternal = 1 |
| SymVerStatic = 10 // Minimum version used by static (file-local) syms |
| ) |
| |
| func ABIToVersion(abi obj.ABI) int { |
| switch abi { |
| case obj.ABI0: |
| return SymVerABI0 |
| case obj.ABIInternal: |
| return SymVerABIInternal |
| } |
| return -1 |
| } |
| |
| func VersionToABI(v int) (obj.ABI, bool) { |
| switch v { |
| case SymVerABI0: |
| return obj.ABI0, true |
| case SymVerABIInternal: |
| return obj.ABIInternal, true |
| } |
| return ^obj.ABI(0), false |
| } |
| |
| func (s *Symbol) String() string { |
| if s.Version == 0 { |
| return s.Name |
| } |
| return fmt.Sprintf("%s<%d>", s.Name, s.Version) |
| } |
| |
| func (s *Symbol) IsFileLocal() bool { |
| return s.Version >= SymVerStatic |
| } |
| |
| func (s *Symbol) ElfsymForReloc() int32 { |
| // If putelfsym created a local version of this symbol, use that in all |
| // relocations. |
| if s.LocalElfsym != 0 { |
| return s.LocalElfsym |
| } else { |
| return s.Elfsym |
| } |
| } |
| |
| func (s *Symbol) Len() int64 { |
| return s.Size |
| } |
| |
| func (s *Symbol) Grow(siz int64) { |
| if int64(int(siz)) != siz { |
| log.Fatalf("symgrow size %d too long", siz) |
| } |
| if int64(len(s.P)) >= siz { |
| return |
| } |
| if cap(s.P) < int(siz) { |
| p := make([]byte, 2*(siz+1)) |
| s.P = append(p[:0], s.P...) |
| } |
| s.P = s.P[:siz] |
| } |
| |
| func (s *Symbol) AddBytes(bytes []byte) int64 { |
| if s.Type == 0 { |
| s.Type = SDATA |
| } |
| s.Attr |= AttrReachable |
| s.P = append(s.P, bytes...) |
| s.Size = int64(len(s.P)) |
| |
| return s.Size |
| } |
| |
| func (s *Symbol) AddUint8(v uint8) int64 { |
| off := s.Size |
| if s.Type == 0 { |
| s.Type = SDATA |
| } |
| s.Attr |= AttrReachable |
| s.Size++ |
| s.P = append(s.P, v) |
| |
| return off |
| } |
| |
| func (s *Symbol) AddUint16(arch *sys.Arch, v uint16) int64 { |
| return s.AddUintXX(arch, uint64(v), 2) |
| } |
| |
| func (s *Symbol) AddUint32(arch *sys.Arch, v uint32) int64 { |
| return s.AddUintXX(arch, uint64(v), 4) |
| } |
| |
| func (s *Symbol) AddUint64(arch *sys.Arch, v uint64) int64 { |
| return s.AddUintXX(arch, v, 8) |
| } |
| |
| func (s *Symbol) AddUint(arch *sys.Arch, v uint64) int64 { |
| return s.AddUintXX(arch, v, arch.PtrSize) |
| } |
| |
| func (s *Symbol) SetUint8(arch *sys.Arch, r int64, v uint8) int64 { |
| return s.setUintXX(arch, r, uint64(v), 1) |
| } |
| |
| func (s *Symbol) SetUint16(arch *sys.Arch, r int64, v uint16) int64 { |
| return s.setUintXX(arch, r, uint64(v), 2) |
| } |
| |
| func (s *Symbol) SetUint32(arch *sys.Arch, r int64, v uint32) int64 { |
| return s.setUintXX(arch, r, uint64(v), 4) |
| } |
| |
| func (s *Symbol) SetUint(arch *sys.Arch, r int64, v uint64) int64 { |
| return s.setUintXX(arch, r, v, int64(arch.PtrSize)) |
| } |
| |
| func (s *Symbol) addAddrPlus(arch *sys.Arch, t *Symbol, add int64, typ objabi.RelocType) int64 { |
| if s.Type == 0 { |
| s.Type = SDATA |
| } |
| s.Attr |= AttrReachable |
| i := s.Size |
| s.Size += int64(arch.PtrSize) |
| s.Grow(s.Size) |
| r := s.AddRel() |
| r.Sym = t |
| r.Off = int32(i) |
| r.Siz = uint8(arch.PtrSize) |
| r.Type = typ |
| r.Add = add |
| return i + int64(r.Siz) |
| } |
| |
| func (s *Symbol) AddAddrPlus(arch *sys.Arch, t *Symbol, add int64) int64 { |
| return s.addAddrPlus(arch, t, add, objabi.R_ADDR) |
| } |
| |
| func (s *Symbol) AddCURelativeAddrPlus(arch *sys.Arch, t *Symbol, add int64) int64 { |
| return s.addAddrPlus(arch, t, add, objabi.R_ADDRCUOFF) |
| } |
| |
| func (s *Symbol) AddPCRelPlus(arch *sys.Arch, t *Symbol, add int64) int64 { |
| if s.Type == 0 { |
| s.Type = SDATA |
| } |
| s.Attr |= AttrReachable |
| i := s.Size |
| s.Size += 4 |
| s.Grow(s.Size) |
| r := s.AddRel() |
| r.Sym = t |
| r.Off = int32(i) |
| r.Add = add |
| r.Type = objabi.R_PCREL |
| r.Siz = 4 |
| if arch.Family == sys.S390X || arch.Family == sys.PPC64 { |
| r.InitExt() |
| } |
| if arch.Family == sys.S390X { |
| r.Variant = RV_390_DBL |
| } |
| return i + int64(r.Siz) |
| } |
| |
| func (s *Symbol) AddAddr(arch *sys.Arch, t *Symbol) int64 { |
| return s.AddAddrPlus(arch, t, 0) |
| } |
| |
| func (s *Symbol) SetAddrPlus(arch *sys.Arch, off int64, t *Symbol, add int64) int64 { |
| if s.Type == 0 { |
| s.Type = SDATA |
| } |
| s.Attr |= AttrReachable |
| if off+int64(arch.PtrSize) > s.Size { |
| s.Size = off + int64(arch.PtrSize) |
| s.Grow(s.Size) |
| } |
| |
| r := s.AddRel() |
| r.Sym = t |
| r.Off = int32(off) |
| r.Siz = uint8(arch.PtrSize) |
| r.Type = objabi.R_ADDR |
| r.Add = add |
| return off + int64(r.Siz) |
| } |
| |
| func (s *Symbol) SetAddr(arch *sys.Arch, off int64, t *Symbol) int64 { |
| return s.SetAddrPlus(arch, off, t, 0) |
| } |
| |
| func (s *Symbol) AddSize(arch *sys.Arch, t *Symbol) int64 { |
| if s.Type == 0 { |
| s.Type = SDATA |
| } |
| s.Attr |= AttrReachable |
| i := s.Size |
| s.Size += int64(arch.PtrSize) |
| s.Grow(s.Size) |
| r := s.AddRel() |
| r.Sym = t |
| r.Off = int32(i) |
| r.Siz = uint8(arch.PtrSize) |
| r.Type = objabi.R_SIZE |
| return i + int64(r.Siz) |
| } |
| |
| func (s *Symbol) AddAddrPlus4(t *Symbol, add int64) int64 { |
| if s.Type == 0 { |
| s.Type = SDATA |
| } |
| s.Attr |= AttrReachable |
| i := s.Size |
| s.Size += 4 |
| s.Grow(s.Size) |
| r := s.AddRel() |
| r.Sym = t |
| r.Off = int32(i) |
| r.Siz = 4 |
| r.Type = objabi.R_ADDR |
| r.Add = add |
| return i + int64(r.Siz) |
| } |
| |
| func (s *Symbol) AddRel() *Reloc { |
| s.R = append(s.R, Reloc{}) |
| return &s.R[len(s.R)-1] |
| } |
| |
| func (s *Symbol) AddUintXX(arch *sys.Arch, v uint64, wid int) int64 { |
| off := s.Size |
| s.setUintXX(arch, off, v, int64(wid)) |
| return off |
| } |
| |
| func (s *Symbol) setUintXX(arch *sys.Arch, off int64, v uint64, wid int64) int64 { |
| if s.Type == 0 { |
| s.Type = SDATA |
| } |
| s.Attr |= AttrReachable |
| if s.Size < off+wid { |
| s.Size = off + wid |
| s.Grow(s.Size) |
| } |
| |
| switch wid { |
| case 1: |
| s.P[off] = uint8(v) |
| case 2: |
| arch.ByteOrder.PutUint16(s.P[off:], uint16(v)) |
| case 4: |
| arch.ByteOrder.PutUint32(s.P[off:], uint32(v)) |
| case 8: |
| arch.ByteOrder.PutUint64(s.P[off:], v) |
| } |
| |
| return off + wid |
| } |
| |
| func (s *Symbol) makeAuxInfo() { |
| if s.auxinfo == nil { |
| s.auxinfo = &AuxSymbol{extname: s.Name, plt: -1, got: -1} |
| } |
| } |
| |
| func (s *Symbol) Extname() string { |
| if s.auxinfo == nil { |
| return s.Name |
| } |
| return s.auxinfo.extname |
| } |
| |
| func (s *Symbol) SetExtname(n string) { |
| if s.auxinfo == nil { |
| if s.Name == n { |
| return |
| } |
| s.makeAuxInfo() |
| } |
| s.auxinfo.extname = n |
| } |
| |
| func (s *Symbol) Dynimplib() string { |
| if s.auxinfo == nil { |
| return "" |
| } |
| return s.auxinfo.dynimplib |
| } |
| |
| func (s *Symbol) Dynimpvers() string { |
| if s.auxinfo == nil { |
| return "" |
| } |
| return s.auxinfo.dynimpvers |
| } |
| |
| func (s *Symbol) SetDynimplib(lib string) { |
| if s.auxinfo == nil { |
| s.makeAuxInfo() |
| } |
| s.auxinfo.dynimplib = lib |
| } |
| |
| func (s *Symbol) SetDynimpvers(vers string) { |
| if s.auxinfo == nil { |
| s.makeAuxInfo() |
| } |
| s.auxinfo.dynimpvers = vers |
| } |
| |
| func (s *Symbol) ResetDyninfo() { |
| if s.auxinfo != nil { |
| s.auxinfo.dynimplib = "" |
| s.auxinfo.dynimpvers = "" |
| } |
| } |
| |
| func (s *Symbol) Localentry() uint8 { |
| if s.auxinfo == nil { |
| return 0 |
| } |
| return s.auxinfo.localentry |
| } |
| |
| func (s *Symbol) SetLocalentry(val uint8) { |
| if s.auxinfo == nil { |
| if val != 0 { |
| return |
| } |
| s.makeAuxInfo() |
| } |
| s.auxinfo.localentry = val |
| } |
| |
| func (s *Symbol) Plt() int32 { |
| if s.auxinfo == nil { |
| return -1 |
| } |
| return s.auxinfo.plt |
| } |
| |
| func (s *Symbol) SetPlt(val int32) { |
| if s.auxinfo == nil { |
| if val == -1 { |
| return |
| } |
| s.makeAuxInfo() |
| } |
| s.auxinfo.plt = val |
| } |
| |
| func (s *Symbol) Got() int32 { |
| if s.auxinfo == nil { |
| return -1 |
| } |
| return s.auxinfo.got |
| } |
| |
| func (s *Symbol) SetGot(val int32) { |
| if s.auxinfo == nil { |
| if val == -1 { |
| return |
| } |
| s.makeAuxInfo() |
| } |
| s.auxinfo.got = val |
| } |
| |
| func (s *Symbol) ElfType() elf.SymType { |
| if s.auxinfo == nil { |
| return elf.STT_NOTYPE |
| } |
| return s.auxinfo.elftype |
| } |
| |
| func (s *Symbol) SetElfType(val elf.SymType) { |
| if s.auxinfo == nil { |
| if val == elf.STT_NOTYPE { |
| return |
| } |
| s.makeAuxInfo() |
| } |
| s.auxinfo.elftype = val |
| } |
| |
| // SortSub sorts a linked-list (by Sub) of *Symbol by Value. |
| // Used for sub-symbols when loading host objects (see e.g. ldelf.go). |
| func SortSub(l *Symbol) *Symbol { |
| if l == nil || l.Sub == nil { |
| return l |
| } |
| |
| l1 := l |
| l2 := l |
| for { |
| l2 = l2.Sub |
| if l2 == nil { |
| break |
| } |
| l2 = l2.Sub |
| if l2 == nil { |
| break |
| } |
| l1 = l1.Sub |
| } |
| |
| l2 = l1.Sub |
| l1.Sub = nil |
| l1 = SortSub(l) |
| l2 = SortSub(l2) |
| |
| /* set up lead element */ |
| if l1.Value < l2.Value { |
| l = l1 |
| l1 = l1.Sub |
| } else { |
| l = l2 |
| l2 = l2.Sub |
| } |
| |
| le := l |
| |
| for { |
| if l1 == nil { |
| for l2 != nil { |
| le.Sub = l2 |
| le = l2 |
| l2 = l2.Sub |
| } |
| |
| le.Sub = nil |
| break |
| } |
| |
| if l2 == nil { |
| for l1 != nil { |
| le.Sub = l1 |
| le = l1 |
| l1 = l1.Sub |
| } |
| |
| break |
| } |
| |
| if l1.Value < l2.Value { |
| le.Sub = l1 |
| le = l1 |
| l1 = l1.Sub |
| } else { |
| le.Sub = l2 |
| le = l2 |
| l2 = l2.Sub |
| } |
| } |
| |
| le.Sub = nil |
| return l |
| } |
| |
| type FuncInfo struct { |
| Args int32 |
| Locals int32 |
| Pcsp Pcdata |
| Pcfile Pcdata |
| Pcline Pcdata |
| Pcinline Pcdata |
| Pcdata []Pcdata |
| Funcdata []*Symbol |
| Funcdataoff []int64 |
| File []*Symbol |
| InlTree []InlinedCall |
| } |
| |
| // InlinedCall is a node in a local inlining tree (FuncInfo.InlTree). |
| type InlinedCall struct { |
| Parent int32 // index of parent in InlTree |
| File *Symbol // file of the inlined call |
| Line int32 // line number of the inlined call |
| Func string // name of the function that was inlined |
| ParentPC int32 // PC of the instruction just before the inlined body (offset from function start) |
| } |
| |
| type Pcdata struct { |
| P []byte |
| } |
