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"
14 // SymbolBuilder is a helper designed to help with the construction
15 // of new symbol contents.
16 type SymbolBuilder struct {
17 *extSymPayload // points to payload being updated
18 symIdx Sym // index of symbol being updated/constructed
22 // MakeSymbolBuilder creates a symbol builder for use in constructing
23 // an entirely new symbol.
24 func (l *Loader) MakeSymbolBuilder(name string) *SymbolBuilder {
25 // for now assume that any new sym is intended to be static
26 symIdx := l.CreateExtSym(name)
27 if l.Syms[symIdx] != nil {
28 panic("can't build if sym.Symbol already present")
30 sb := &SymbolBuilder{l: l, symIdx: symIdx}
31 sb.extSymPayload = l.payloads[symIdx-l.extStart]
35 // MakeSymbolUpdater creates a symbol builder helper for an existing
36 // symbol 'symIdx'. If 'symIdx' is not an external symbol, then create
37 // a clone of it (copy name, properties, etc) fix things up so that
38 // the lookup tables and caches point to the new version, not the old
39 // version. Returns a SymbolBuilder and a Sym (which may be different
40 // from the original if we had to clone).
41 func (l *Loader) MakeSymbolUpdater(symIdx Sym) (*SymbolBuilder, Sym) {
43 panic("can't update the null symbol")
45 symIdx = l.getOverwrite(symIdx)
46 if !l.IsExternal(symIdx) {
47 // Create a clone with the same name/version/kind etc.
48 symIdx = l.cloneToExternal(symIdx)
50 if l.Syms[symIdx] != nil {
51 panic(fmt.Sprintf("can't build if sym.Symbol %q already present", l.RawSymName(symIdx)))
54 // Construct updater and return.
55 sb := &SymbolBuilder{l: l, symIdx: symIdx}
56 sb.extSymPayload = l.payloads[symIdx-l.extStart]
60 // Getters for properties of the symbol we're working on.
62 func (sb *SymbolBuilder) Sym() Sym { return sb.symIdx }
63 func (sb *SymbolBuilder) Name() string { return sb.name }
64 func (sb *SymbolBuilder) Version() int { return sb.ver }
65 func (sb *SymbolBuilder) Type() sym.SymKind { return sb.kind }
66 func (sb *SymbolBuilder) Size() int64 { return sb.size }
67 func (sb *SymbolBuilder) Data() []byte { return sb.data }
68 func (sb *SymbolBuilder) Value() int64 { return sb.l.SymValue(sb.symIdx) }
69 func (sb *SymbolBuilder) Align() int32 { return sb.l.SymAlign(sb.symIdx) }
70 func (sb *SymbolBuilder) Localentry() uint8 { return sb.l.SymLocalentry(sb.symIdx) }
71 func (sb *SymbolBuilder) OnList() bool { return sb.l.AttrOnList(sb.symIdx) }
72 func (sb *SymbolBuilder) External() bool { return sb.l.AttrExternal(sb.symIdx) }
73 func (sb *SymbolBuilder) Extname() string { return sb.l.SymExtname(sb.symIdx) }
74 func (sb *SymbolBuilder) CgoExportDynamic() bool { return sb.l.AttrCgoExportDynamic(sb.symIdx) }
75 func (sb *SymbolBuilder) Dynimplib() string { return sb.l.SymDynimplib(sb.symIdx) }
76 func (sb *SymbolBuilder) Dynimpvers() string { return sb.l.SymDynimpvers(sb.symIdx) }
77 func (sb *SymbolBuilder) SubSym() Sym { return sb.l.SubSym(sb.symIdx) }
79 // Setters for symbol properties.
81 func (sb *SymbolBuilder) SetType(kind sym.SymKind) { sb.kind = kind }
82 func (sb *SymbolBuilder) SetSize(size int64) { sb.size = size }
83 func (sb *SymbolBuilder) SetData(data []byte) { sb.data = data }
84 func (sb *SymbolBuilder) SetOnList(v bool) { sb.l.SetAttrOnList(sb.symIdx, v) }
85 func (sb *SymbolBuilder) SetExternal(v bool) { sb.l.SetAttrExternal(sb.symIdx, v) }
86 func (sb *SymbolBuilder) SetValue(v int64) { sb.l.SetSymValue(sb.symIdx, v) }
87 func (sb *SymbolBuilder) SetAlign(align int32) { sb.l.SetSymAlign(sb.symIdx, align) }
88 func (sb *SymbolBuilder) SetLocalentry(value uint8) { sb.l.SetSymLocalentry(sb.symIdx, value) }
89 func (sb *SymbolBuilder) SetExtname(value string) { sb.l.SetSymExtname(sb.symIdx, value) }
90 func (sb *SymbolBuilder) SetDynimplib(value string) { sb.l.SetSymDynimplib(sb.symIdx, value) }
91 func (sb *SymbolBuilder) SetDynimpvers(value string) { sb.l.SetSymDynimpvers(sb.symIdx, value) }
93 func (sb *SymbolBuilder) AddBytes(data []byte) {
98 sb.data = append(sb.data, data...)
99 sb.size = int64(len(sb.data))
102 func (sb *SymbolBuilder) Relocs() []Reloc {
106 func (sb *SymbolBuilder) SetRelocs(rslice []Reloc) {
110 func (sb *SymbolBuilder) AddReloc(r Reloc) {
111 sb.relocs = append(sb.relocs, r)
114 func (sb *SymbolBuilder) Reachable() bool {
115 return sb.l.AttrReachable(sb.symIdx)
118 func (sb *SymbolBuilder) setReachable() {
119 sb.l.SetAttrReachable(sb.symIdx, true)
122 func (sb *SymbolBuilder) ReadOnly() bool {
123 return sb.l.AttrReadOnly(sb.symIdx)
126 func (sb *SymbolBuilder) SetReadOnly(v bool) {
127 sb.l.SetAttrReadOnly(sb.symIdx, v)
130 func (sb *SymbolBuilder) DuplicateOK() bool {
131 return sb.l.AttrDuplicateOK(sb.symIdx)
134 func (sb *SymbolBuilder) SetDuplicateOK(v bool) {
135 sb.l.SetAttrDuplicateOK(sb.symIdx, v)
138 func (sb *SymbolBuilder) Outer() Sym {
139 return sb.l.OuterSym(sb.symIdx)
142 func (sb *SymbolBuilder) Sub() Sym {
143 return sb.l.SubSym(sb.symIdx)
146 func (sb *SymbolBuilder) SortSub() {
147 sb.l.SortSub(sb.symIdx)
150 func (sb *SymbolBuilder) PrependSub(sub Sym) {
151 sb.l.PrependSub(sb.symIdx, sub)
154 func (sb *SymbolBuilder) AddUint8(v uint8) int64 {
161 sb.data = append(sb.data, v)
165 func (sb *SymbolBuilder) AddUintXX(arch *sys.Arch, v uint64, wid int) int64 {
168 sb.setUintXX(arch, off, v, int64(wid))
172 func (sb *SymbolBuilder) setUintXX(arch *sys.Arch, off int64, v uint64, wid int64) int64 {
176 if sb.size < off+wid {
183 sb.data[off] = uint8(v)
185 arch.ByteOrder.PutUint16(sb.data[off:], uint16(v))
187 arch.ByteOrder.PutUint32(sb.data[off:], uint32(v))
189 arch.ByteOrder.PutUint64(sb.data[off:], v)
195 func (sb *SymbolBuilder) AddUint16(arch *sys.Arch, v uint16) int64 {
196 return sb.AddUintXX(arch, uint64(v), 2)
199 func (sb *SymbolBuilder) AddUint32(arch *sys.Arch, v uint32) int64 {
200 return sb.AddUintXX(arch, uint64(v), 4)
203 func (sb *SymbolBuilder) AddUint64(arch *sys.Arch, v uint64) int64 {
204 return sb.AddUintXX(arch, v, 8)
207 func (sb *SymbolBuilder) AddUint(arch *sys.Arch, v uint64) int64 {
208 return sb.AddUintXX(arch, v, arch.PtrSize)
211 func (sb *SymbolBuilder) SetUint8(arch *sys.Arch, r int64, v uint8) int64 {
213 return sb.setUintXX(arch, r, uint64(v), 1)
216 func (sb *SymbolBuilder) SetUint16(arch *sys.Arch, r int64, v uint16) int64 {
218 return sb.setUintXX(arch, r, uint64(v), 2)
221 func (sb *SymbolBuilder) SetUint32(arch *sys.Arch, r int64, v uint32) int64 {
223 return sb.setUintXX(arch, r, uint64(v), 4)
226 func (sb *SymbolBuilder) SetUint(arch *sys.Arch, r int64, v uint64) int64 {
228 return sb.setUintXX(arch, r, v, int64(arch.PtrSize))
231 func (sb *SymbolBuilder) Addstring(str string) int64 {
234 sb.kind = sym.SNOPTRDATA
237 if sb.name == ".shstrtab" {
238 // FIXME: find a better mechanism for this
239 sb.l.elfsetstring(nil, str, int(r))
241 sb.data = append(sb.data, str...)
242 sb.data = append(sb.data, 0)
243 sb.size = int64(len(sb.data))
247 func (sb *SymbolBuilder) addRel() *Reloc {
248 sb.relocs = append(sb.relocs, Reloc{})
249 return &sb.relocs[len(sb.relocs)-1]
252 func (sb *SymbolBuilder) addAddrPlus(tgt Sym, add int64, typ objabi.RelocType, rsize int) int64 {
258 sb.size += int64(rsize)
264 r.Size = uint8(rsize)
268 return i + int64(r.Size)
271 func (sb *SymbolBuilder) AddAddrPlus(arch *sys.Arch, tgt Sym, add int64) int64 {
273 return sb.addAddrPlus(tgt, add, objabi.R_ADDR, arch.PtrSize)
276 func (sb *SymbolBuilder) AddAddrPlus4(arch *sys.Arch, tgt Sym, add int64) int64 {
278 return sb.addAddrPlus(tgt, add, objabi.R_ADDR, 4)
281 func (sb *SymbolBuilder) AddCURelativeAddrPlus(arch *sys.Arch, tgt Sym, add int64) int64 {
283 return sb.addAddrPlus(tgt, add, objabi.R_ADDRCUOFF, arch.PtrSize)