1 // Copyright 2019 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
10 "cmd/link/internal/sym"
13 // SymbolBuilder is a helper designed to help with the construction
14 // of new symbol contents.
15 type SymbolBuilder struct {
16 *extSymPayload // points to payload being updated
17 symIdx Sym // index of symbol being updated/constructed
21 // MakeSymbolBuilder creates a symbol builder for use in constructing
22 // an entirely new symbol.
23 func (l *Loader) MakeSymbolBuilder(name string) *SymbolBuilder {
24 // for now assume that any new sym is intended to be static
25 symIdx := l.CreateExtSym(name)
26 if l.Syms[symIdx] != nil {
27 panic("can't build if sym.Symbol already present")
29 sb := &SymbolBuilder{l: l, symIdx: symIdx}
30 sb.extSymPayload = &l.payloads[symIdx-l.extStart]
34 // MakeSymbolUpdater creates a symbol builder helper for an existing
35 // symbol 'symIdx'. If 'symIdx' is not an external symbol, then create
36 // a clone of it (copy name, properties, etc) fix things up so that
37 // the lookup tables and caches point to the new version, not the old
38 // version. Returns a SymbolBuilder and a Sym (which may be different
39 // from the original if we had to clone).
40 func (l *Loader) MakeSymbolUpdater(symIdx Sym) (*SymbolBuilder, Sym) {
42 panic("can't update the null symbol")
44 symIdx = l.getOverwrite(symIdx)
45 if !l.IsExternal(symIdx) {
46 // Create a clone with the same name/version/kind etc.
47 symIdx = l.cloneToExternal(symIdx)
49 if l.Syms[symIdx] != nil {
50 panic("can't build if sym.Symbol already present")
53 // Construct updater and return.
54 sb := &SymbolBuilder{l: l, symIdx: symIdx}
55 sb.extSymPayload = &l.payloads[symIdx-l.extStart]
59 // Getters for properties of the symbol we're working on.
61 func (sb *SymbolBuilder) Sym() Sym { return sb.symIdx }
62 func (sb *SymbolBuilder) Name() string { return sb.name }
63 func (sb *SymbolBuilder) Version() int { return sb.ver }
64 func (sb *SymbolBuilder) Type() sym.SymKind { return sb.kind }
65 func (sb *SymbolBuilder) Size() int64 { return sb.size }
66 func (sb *SymbolBuilder) Data() []byte { return sb.data }
67 func (sb *SymbolBuilder) Value() int64 { return sb.l.SymValue(sb.symIdx) }
68 func (sb *SymbolBuilder) Align() int32 { return sb.l.SymAlign(sb.symIdx) }
69 func (sb *SymbolBuilder) Localentry() uint8 { return sb.l.SymLocalentry(sb.symIdx) }
70 func (sb *SymbolBuilder) Extname() string { return sb.l.SymExtname(sb.symIdx) }
71 func (sb *SymbolBuilder) Dynimplib() string { return sb.l.SymDynimplib(sb.symIdx) }
72 func (sb *SymbolBuilder) Dynimpvers() string { return sb.l.SymDynimpvers(sb.symIdx) }
74 // Setters for symbol properties.
76 func (sb *SymbolBuilder) SetType(kind sym.SymKind) { sb.kind = kind }
77 func (sb *SymbolBuilder) SetSize(size int64) { sb.size = size }
78 func (sb *SymbolBuilder) SetData(data []byte) { sb.data = data }
79 func (sb *SymbolBuilder) SetValue(v int64) { sb.l.SetSymValue(sb.symIdx, v) }
80 func (sb *SymbolBuilder) SetAlign(align int32) { sb.l.SetSymAlign(sb.symIdx, align) }
81 func (sb *SymbolBuilder) SetLocalentry(value uint8) { sb.l.SetSymLocalentry(sb.symIdx, value) }
82 func (sb *SymbolBuilder) SetExtname(value string) { sb.l.SetSymExtname(sb.symIdx, value) }
83 func (sb *SymbolBuilder) SetDynimplib(value string) { sb.l.SetSymDynimplib(sb.symIdx, value) }
84 func (sb *SymbolBuilder) SetDynimpvers(value string) { sb.l.SetSymDynimpvers(sb.symIdx, value) }
86 func (sb *SymbolBuilder) AddBytes(data []byte) {
91 sb.data = append(sb.data, data...)
92 sb.size = int64(len(sb.data))
95 func (sb *SymbolBuilder) Relocs() []Reloc {
99 func (sb *SymbolBuilder) SetRelocs(rslice []Reloc) {
103 func (sb *SymbolBuilder) AddReloc(r Reloc) {
104 sb.relocs = append(sb.relocs, r)
107 func (sb *SymbolBuilder) Reachable() bool {
108 return sb.l.AttrReachable(sb.symIdx)
111 func (sb *SymbolBuilder) setReachable() {
112 sb.l.SetAttrReachable(sb.symIdx, true)
115 func (sb *SymbolBuilder) Outer() Sym {
116 return sb.l.OuterSym(sb.symIdx)
119 func (sb *SymbolBuilder) Sub() Sym {
120 return sb.l.SubSym(sb.symIdx)
123 func (sb *SymbolBuilder) SortSub() {
124 sb.l.SortSub(sb.symIdx)
127 func (sb *SymbolBuilder) PrependSub(sub Sym) {
128 sb.l.PrependSub(sb.symIdx, sub)
131 func (sb *SymbolBuilder) AddUint8(v uint8) int64 {
138 sb.data = append(sb.data, v)
142 func (sb *SymbolBuilder) AddUintXX(arch *sys.Arch, v uint64, wid int) int64 {
145 sb.setUintXX(arch, off, v, int64(wid))
149 func (sb *SymbolBuilder) setUintXX(arch *sys.Arch, off int64, v uint64, wid int64) int64 {
153 if sb.size < off+wid {
160 sb.data[off] = uint8(v)
162 arch.ByteOrder.PutUint16(sb.data[off:], uint16(v))
164 arch.ByteOrder.PutUint32(sb.data[off:], uint32(v))
166 arch.ByteOrder.PutUint64(sb.data[off:], v)
172 func (sb *SymbolBuilder) AddUint16(arch *sys.Arch, v uint16) int64 {
173 return sb.AddUintXX(arch, uint64(v), 2)
176 func (sb *SymbolBuilder) AddUint32(arch *sys.Arch, v uint32) int64 {
177 return sb.AddUintXX(arch, uint64(v), 4)
180 func (sb *SymbolBuilder) AddUint64(arch *sys.Arch, v uint64) int64 {
181 return sb.AddUintXX(arch, v, 8)
184 func (sb *SymbolBuilder) AddUint(arch *sys.Arch, v uint64) int64 {
185 return sb.AddUintXX(arch, v, arch.PtrSize)
188 func (sb *SymbolBuilder) SetUint8(arch *sys.Arch, r int64, v uint8) int64 {
190 return sb.setUintXX(arch, r, uint64(v), 1)
193 func (sb *SymbolBuilder) SetUint16(arch *sys.Arch, r int64, v uint16) int64 {
195 return sb.setUintXX(arch, r, uint64(v), 2)
198 func (sb *SymbolBuilder) SetUint32(arch *sys.Arch, r int64, v uint32) int64 {
200 return sb.setUintXX(arch, r, uint64(v), 4)
203 func (sb *SymbolBuilder) SetUint(arch *sys.Arch, r int64, v uint64) int64 {
205 return sb.setUintXX(arch, r, v, int64(arch.PtrSize))
208 func (sb *SymbolBuilder) Addstring(str string) int64 {
211 sb.kind = sym.SNOPTRDATA
214 if sb.name == ".shstrtab" {
215 // FIXME: find a better mechanism for this
216 sb.l.elfsetstring(nil, str, int(r))
218 sb.data = append(sb.data, str...)
219 sb.data = append(sb.data, 0)
220 sb.size = int64(len(sb.data))
224 func (sb *SymbolBuilder) addRel() *Reloc {
225 sb.relocs = append(sb.relocs, Reloc{})
226 return &sb.relocs[len(sb.relocs)-1]
229 func (sb *SymbolBuilder) addAddrPlus(tgt Sym, add int64, typ objabi.RelocType, rsize int) int64 {
235 sb.size += int64(rsize)
241 r.Size = uint8(rsize)
245 return i + int64(r.Size)
248 func (sb *SymbolBuilder) AddAddrPlus(arch *sys.Arch, tgt Sym, add int64) int64 {
250 return sb.addAddrPlus(tgt, add, objabi.R_ADDR, arch.PtrSize)
253 func (sb *SymbolBuilder) AddAddrPlus4(arch *sys.Arch, tgt Sym, add int64) int64 {
255 return sb.addAddrPlus(tgt, add, objabi.R_ADDR, 4)
258 func (sb *SymbolBuilder) AddCURelativeAddrPlus(arch *sys.Arch, tgt Sym, add int64) int64 {
260 return sb.addAddrPlus(tgt, add, objabi.R_ADDRCUOFF, arch.PtrSize)