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.getPayload(symIdx)
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
40 func (l *Loader) MakeSymbolUpdater(symIdx Sym) *SymbolBuilder {
42 panic("can't update the null symbol")
44 if !l.IsExternal(symIdx) {
45 // Create a clone with the same name/version/kind etc.
46 l.cloneToExternal(symIdx)
48 // Now that we're doing phase 2 DWARF generation using the loader
49 // but before the wavefront has reached dodata(), we can't have this
50 // assertion here. Commented out for now.
52 if l.Syms[symIdx] != nil {
53 panic(fmt.Sprintf("can't build if sym.Symbol %q already present", l.RawSymName(symIdx)))
57 // Construct updater and return.
58 sb := &SymbolBuilder{l: l, symIdx: symIdx}
59 sb.extSymPayload = l.getPayload(symIdx)
63 // CreateSymForUpdate creates a symbol with given name and version,
64 // returns a CreateSymForUpdate for update. If the symbol already
65 // exists, it will update in-place.
66 func (l *Loader) CreateSymForUpdate(name string, version int) *SymbolBuilder {
67 return l.MakeSymbolUpdater(l.LookupOrCreateSym(name, version))
70 // Getters for properties of the symbol we're working on.
72 func (sb *SymbolBuilder) Sym() Sym { return sb.symIdx }
73 func (sb *SymbolBuilder) Name() string { return sb.name }
74 func (sb *SymbolBuilder) Version() int { return sb.ver }
75 func (sb *SymbolBuilder) Type() sym.SymKind { return sb.kind }
76 func (sb *SymbolBuilder) Size() int64 { return sb.size }
77 func (sb *SymbolBuilder) Data() []byte { return sb.data }
78 func (sb *SymbolBuilder) Value() int64 { return sb.l.SymValue(sb.symIdx) }
79 func (sb *SymbolBuilder) Align() int32 { return sb.l.SymAlign(sb.symIdx) }
80 func (sb *SymbolBuilder) Localentry() uint8 { return sb.l.SymLocalentry(sb.symIdx) }
81 func (sb *SymbolBuilder) OnList() bool { return sb.l.AttrOnList(sb.symIdx) }
82 func (sb *SymbolBuilder) External() bool { return sb.l.AttrExternal(sb.symIdx) }
83 func (sb *SymbolBuilder) Extname() string { return sb.l.SymExtname(sb.symIdx) }
84 func (sb *SymbolBuilder) CgoExportDynamic() bool { return sb.l.AttrCgoExportDynamic(sb.symIdx) }
85 func (sb *SymbolBuilder) Dynimplib() string { return sb.l.SymDynimplib(sb.symIdx) }
86 func (sb *SymbolBuilder) Dynimpvers() string { return sb.l.SymDynimpvers(sb.symIdx) }
87 func (sb *SymbolBuilder) SubSym() Sym { return sb.l.SubSym(sb.symIdx) }
88 func (sb *SymbolBuilder) GoType() Sym { return sb.l.SymGoType(sb.symIdx) }
90 // Setters for symbol properties.
92 func (sb *SymbolBuilder) SetType(kind sym.SymKind) { sb.kind = kind }
93 func (sb *SymbolBuilder) SetSize(size int64) { sb.size = size }
94 func (sb *SymbolBuilder) SetData(data []byte) { sb.data = data }
95 func (sb *SymbolBuilder) SetOnList(v bool) { sb.l.SetAttrOnList(sb.symIdx, v) }
96 func (sb *SymbolBuilder) SetExternal(v bool) { sb.l.SetAttrExternal(sb.symIdx, v) }
97 func (sb *SymbolBuilder) SetValue(v int64) { sb.l.SetSymValue(sb.symIdx, v) }
98 func (sb *SymbolBuilder) SetAlign(align int32) { sb.l.SetSymAlign(sb.symIdx, align) }
99 func (sb *SymbolBuilder) SetLocalentry(value uint8) { sb.l.SetSymLocalentry(sb.symIdx, value) }
100 func (sb *SymbolBuilder) SetExtname(value string) { sb.l.SetSymExtname(sb.symIdx, value) }
101 func (sb *SymbolBuilder) SetDynimplib(value string) { sb.l.SetSymDynimplib(sb.symIdx, value) }
102 func (sb *SymbolBuilder) SetDynimpvers(value string) { sb.l.SetSymDynimpvers(sb.symIdx, value) }
103 func (sb *SymbolBuilder) SetPlt(value int32) { sb.l.SetPlt(sb.symIdx, value) }
104 func (sb *SymbolBuilder) SetGot(value int32) { sb.l.SetGot(sb.symIdx, value) }
105 func (sb *SymbolBuilder) SetSpecial(value bool) { sb.l.SetAttrSpecial(sb.symIdx, value) }
107 func (sb *SymbolBuilder) SetNotInSymbolTable(value bool) {
108 sb.l.SetAttrNotInSymbolTable(sb.symIdx, value)
111 func (sb *SymbolBuilder) AddBytes(data []byte) {
116 sb.data = append(sb.data, data...)
117 sb.size = int64(len(sb.data))
120 func (sb *SymbolBuilder) Relocs() []Reloc {
124 func (sb *SymbolBuilder) SetRelocs(rslice []Reloc) {
128 func (sb *SymbolBuilder) WriteRelocs(rslice []Reloc) {
129 if len(sb.relocs) != len(rslice) {
130 panic("src/dest length mismatch")
132 copy(sb.relocs, rslice)
135 func (sb *SymbolBuilder) AddReloc(r Reloc) {
136 sb.relocs = append(sb.relocs, r)
139 func (sb *SymbolBuilder) Reachable() bool {
140 return sb.l.AttrReachable(sb.symIdx)
143 func (sb *SymbolBuilder) SetReachable(v bool) {
144 sb.l.SetAttrReachable(sb.symIdx, v)
147 func (sb *SymbolBuilder) setReachable() {
148 sb.SetReachable(true)
151 func (sb *SymbolBuilder) ReadOnly() bool {
152 return sb.l.AttrReadOnly(sb.symIdx)
155 func (sb *SymbolBuilder) SetReadOnly(v bool) {
156 sb.l.SetAttrReadOnly(sb.symIdx, v)
159 func (sb *SymbolBuilder) DuplicateOK() bool {
160 return sb.l.AttrDuplicateOK(sb.symIdx)
163 func (sb *SymbolBuilder) SetDuplicateOK(v bool) {
164 sb.l.SetAttrDuplicateOK(sb.symIdx, v)
167 func (sb *SymbolBuilder) Outer() Sym {
168 return sb.l.OuterSym(sb.symIdx)
171 func (sb *SymbolBuilder) Sub() Sym {
172 return sb.l.SubSym(sb.symIdx)
175 func (sb *SymbolBuilder) SortSub() {
176 sb.l.SortSub(sb.symIdx)
179 func (sb *SymbolBuilder) PrependSub(sub Sym) {
180 sb.l.PrependSub(sb.symIdx, sub)
183 func (sb *SymbolBuilder) AddUint8(v uint8) int64 {
190 sb.data = append(sb.data, v)
194 func (sb *SymbolBuilder) AddUintXX(arch *sys.Arch, v uint64, wid int) int64 {
197 sb.setUintXX(arch, off, v, int64(wid))
201 func (sb *SymbolBuilder) setUintXX(arch *sys.Arch, off int64, v uint64, wid int64) int64 {
205 if sb.size < off+wid {
212 sb.data[off] = uint8(v)
214 arch.ByteOrder.PutUint16(sb.data[off:], uint16(v))
216 arch.ByteOrder.PutUint32(sb.data[off:], uint32(v))
218 arch.ByteOrder.PutUint64(sb.data[off:], v)
224 func (sb *SymbolBuilder) AddUint16(arch *sys.Arch, v uint16) int64 {
225 return sb.AddUintXX(arch, uint64(v), 2)
228 func (sb *SymbolBuilder) AddUint32(arch *sys.Arch, v uint32) int64 {
229 return sb.AddUintXX(arch, uint64(v), 4)
232 func (sb *SymbolBuilder) AddUint64(arch *sys.Arch, v uint64) int64 {
233 return sb.AddUintXX(arch, v, 8)
236 func (sb *SymbolBuilder) AddUint(arch *sys.Arch, v uint64) int64 {
237 return sb.AddUintXX(arch, v, arch.PtrSize)
240 func (sb *SymbolBuilder) SetUint8(arch *sys.Arch, r int64, v uint8) int64 {
242 return sb.setUintXX(arch, r, uint64(v), 1)
245 func (sb *SymbolBuilder) SetUint16(arch *sys.Arch, r int64, v uint16) int64 {
247 return sb.setUintXX(arch, r, uint64(v), 2)
250 func (sb *SymbolBuilder) SetUint32(arch *sys.Arch, r int64, v uint32) int64 {
252 return sb.setUintXX(arch, r, uint64(v), 4)
255 func (sb *SymbolBuilder) SetUint(arch *sys.Arch, r int64, v uint64) int64 {
257 return sb.setUintXX(arch, r, v, int64(arch.PtrSize))
260 func (sb *SymbolBuilder) Addstring(str string) int64 {
263 sb.kind = sym.SNOPTRDATA
266 if sb.name == ".shstrtab" {
267 // FIXME: find a better mechanism for this
268 sb.l.elfsetstring(nil, str, int(r))
270 sb.data = append(sb.data, str...)
271 sb.data = append(sb.data, 0)
272 sb.size = int64(len(sb.data))
276 func (sb *SymbolBuilder) addRel() *Reloc {
277 sb.relocs = append(sb.relocs, Reloc{})
278 return &sb.relocs[len(sb.relocs)-1]
281 func (sb *SymbolBuilder) addSymRef(tgt Sym, add int64, typ objabi.RelocType, rsize int) int64 {
287 sb.size += int64(rsize)
293 r.Size = uint8(rsize)
297 return i + int64(r.Size)
300 // Add a symbol reference (relocation) with given type, addend, and size
301 // (the most generic form).
302 func (sb *SymbolBuilder) AddSymRef(arch *sys.Arch, tgt Sym, add int64, typ objabi.RelocType, rsize int) int64 {
304 return sb.addSymRef(tgt, add, typ, rsize)
307 func (sb *SymbolBuilder) AddAddrPlus(arch *sys.Arch, tgt Sym, add int64) int64 {
309 return sb.addSymRef(tgt, add, objabi.R_ADDR, arch.PtrSize)
312 func (sb *SymbolBuilder) AddAddrPlus4(arch *sys.Arch, tgt Sym, add int64) int64 {
314 return sb.addSymRef(tgt, add, objabi.R_ADDR, 4)
317 func (sb *SymbolBuilder) AddPCRelPlus(arch *sys.Arch, tgt Sym, add int64) int64 {
319 return sb.addSymRef(tgt, add, objabi.R_PCREL, 4)
322 func (sb *SymbolBuilder) AddCURelativeAddrPlus(arch *sys.Arch, tgt Sym, add int64) int64 {
324 return sb.addSymRef(tgt, add, objabi.R_ADDRCUOFF, arch.PtrSize)
327 func (sb *SymbolBuilder) AddSize(arch *sys.Arch, tgt Sym) int64 {
329 return sb.addSymRef(tgt, 0, objabi.R_SIZE, arch.PtrSize)