/Users/buildslave/jenkins/sharedspace/clang-stage2-coverage-R@2/llvm/include/llvm/MC/MCMachObjectWriter.h
Line | Count | Source (jump to first uncovered line) |
1 | | //===- llvm/MC/MCMachObjectWriter.h - Mach Object Writer --------*- C++ -*-===// |
2 | | // |
3 | | // The LLVM Compiler Infrastructure |
4 | | // |
5 | | // This file is distributed under the University of Illinois Open Source |
6 | | // License. See LICENSE.TXT for details. |
7 | | // |
8 | | //===----------------------------------------------------------------------===// |
9 | | |
10 | | #ifndef LLVM_MC_MCMACHOBJECTWRITER_H |
11 | | #define LLVM_MC_MCMACHOBJECTWRITER_H |
12 | | |
13 | | #include "llvm/ADT/DenseMap.h" |
14 | | #include "llvm/ADT/StringRef.h" |
15 | | #include "llvm/BinaryFormat/MachO.h" |
16 | | #include "llvm/MC/MCExpr.h" |
17 | | #include "llvm/MC/MCObjectWriter.h" |
18 | | #include "llvm/MC/MCSection.h" |
19 | | #include "llvm/MC/StringTableBuilder.h" |
20 | | #include <cstdint> |
21 | | #include <memory> |
22 | | #include <string> |
23 | | #include <vector> |
24 | | |
25 | | namespace llvm { |
26 | | |
27 | | class MachObjectWriter; |
28 | | |
29 | | class MCMachObjectTargetWriter { |
30 | | const unsigned Is64Bit : 1; |
31 | | const uint32_t CPUType; |
32 | | const uint32_t CPUSubtype; |
33 | | unsigned LocalDifference_RIT; |
34 | | |
35 | | protected: |
36 | | MCMachObjectTargetWriter(bool Is64Bit_, uint32_t CPUType_, |
37 | | uint32_t CPUSubtype_); |
38 | | |
39 | 0 | void setLocalDifferenceRelocationType(unsigned Type) { |
40 | 0 | LocalDifference_RIT = Type; |
41 | 0 | } |
42 | | |
43 | | public: |
44 | | virtual ~MCMachObjectTargetWriter(); |
45 | | |
46 | | /// \name Lifetime Management |
47 | | /// @{ |
48 | | |
49 | 0 | virtual void reset() {} |
50 | | |
51 | | /// @} |
52 | | |
53 | | /// \name Accessors |
54 | | /// @{ |
55 | | |
56 | 1.93M | bool is64Bit() const { return Is64Bit; } |
57 | 4.11M | uint32_t getCPUType() const { return CPUType; } |
58 | 18.3k | uint32_t getCPUSubtype() const { return CPUSubtype; } |
59 | 0 | unsigned getLocalDifferenceRelocationType() const { |
60 | 0 | return LocalDifference_RIT; |
61 | 0 | } |
62 | | |
63 | | /// @} |
64 | | |
65 | | /// \name API |
66 | | /// @{ |
67 | | |
68 | | virtual void recordRelocation(MachObjectWriter *Writer, MCAssembler &Asm, |
69 | | const MCAsmLayout &Layout, |
70 | | const MCFragment *Fragment, |
71 | | const MCFixup &Fixup, MCValue Target, |
72 | | uint64_t &FixedValue) = 0; |
73 | | |
74 | | /// @} |
75 | | }; |
76 | | |
77 | | class MachObjectWriter : public MCObjectWriter { |
78 | | /// Helper struct for containing some precomputed information on symbols. |
79 | | struct MachSymbolData { |
80 | | const MCSymbol *Symbol; |
81 | | uint64_t StringIndex; |
82 | | uint8_t SectionIndex; |
83 | | |
84 | | // Support lexicographic sorting. |
85 | | bool operator<(const MachSymbolData &RHS) const; |
86 | | }; |
87 | | |
88 | | /// The target specific Mach-O writer instance. |
89 | | std::unique_ptr<MCMachObjectTargetWriter> TargetObjectWriter; |
90 | | |
91 | | /// \name Relocation Data |
92 | | /// @{ |
93 | | |
94 | | struct RelAndSymbol { |
95 | | const MCSymbol *Sym; |
96 | | MachO::any_relocation_info MRE; |
97 | | RelAndSymbol(const MCSymbol *Sym, const MachO::any_relocation_info &MRE) |
98 | 5.05M | : Sym(Sym), MRE(MRE) {} |
99 | | }; |
100 | | |
101 | | DenseMap<const MCSection *, std::vector<RelAndSymbol>> Relocations; |
102 | | DenseMap<const MCSection *, unsigned> IndirectSymBase; |
103 | | |
104 | | SectionAddrMap SectionAddress; |
105 | | |
106 | | /// @} |
107 | | /// \name Symbol Table Data |
108 | | /// @{ |
109 | | |
110 | | StringTableBuilder StringTable{StringTableBuilder::MachO}; |
111 | | std::vector<MachSymbolData> LocalSymbolData; |
112 | | std::vector<MachSymbolData> ExternalSymbolData; |
113 | | std::vector<MachSymbolData> UndefinedSymbolData; |
114 | | |
115 | | /// @} |
116 | | |
117 | | MachSymbolData *findSymbolData(const MCSymbol &Sym); |
118 | | |
119 | | public: |
120 | | MachObjectWriter(MCMachObjectTargetWriter *MOTW, raw_pwrite_stream &OS, |
121 | | bool IsLittleEndian) |
122 | 18.3k | : MCObjectWriter(OS, IsLittleEndian), TargetObjectWriter(MOTW) {} |
123 | | |
124 | | const MCSymbol &findAliasedSymbol(const MCSymbol &Sym) const; |
125 | | |
126 | | /// \name Lifetime management Methods |
127 | | /// @{ |
128 | | |
129 | | void reset() override; |
130 | | |
131 | | /// @} |
132 | | |
133 | | /// \name Utility Methods |
134 | | /// @{ |
135 | | |
136 | | bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind); |
137 | | |
138 | 7.11k | SectionAddrMap &getSectionAddressMap() { return SectionAddress; } |
139 | | |
140 | 7.23M | uint64_t getSectionAddress(const MCSection *Sec) const { |
141 | 7.23M | return SectionAddress.lookup(Sec); |
142 | 7.23M | } |
143 | | uint64_t getSymbolAddress(const MCSymbol &S, const MCAsmLayout &Layout) const; |
144 | | |
145 | | uint64_t getFragmentAddress(const MCFragment *Fragment, |
146 | | const MCAsmLayout &Layout) const; |
147 | | |
148 | | uint64_t getPaddingSize(const MCSection *SD, const MCAsmLayout &Layout) const; |
149 | | |
150 | | bool doesSymbolRequireExternRelocation(const MCSymbol &S); |
151 | | |
152 | | /// @} |
153 | | |
154 | | /// \name Target Writer Proxy Accessors |
155 | | /// @{ |
156 | | |
157 | 1.93M | bool is64Bit() const { return TargetObjectWriter->is64Bit(); } |
158 | 4.09M | bool isX86_64() const { |
159 | 4.09M | uint32_t CPUType = TargetObjectWriter->getCPUType(); |
160 | 4.09M | return CPUType == MachO::CPU_TYPE_X86_64; |
161 | 4.09M | } |
162 | | |
163 | | /// @} |
164 | | |
165 | | void writeHeader(MachO::HeaderFileType Type, unsigned NumLoadCommands, |
166 | | unsigned LoadCommandsSize, bool SubsectionsViaSymbols); |
167 | | |
168 | | /// Write a segment load command. |
169 | | /// |
170 | | /// \param NumSections The number of sections in this segment. |
171 | | /// \param SectionDataSize The total size of the sections. |
172 | | void writeSegmentLoadCommand(StringRef Name, unsigned NumSections, |
173 | | uint64_t VMAddr, uint64_t VMSize, |
174 | | uint64_t SectionDataStartOffset, |
175 | | uint64_t SectionDataSize, uint32_t MaxProt, |
176 | | uint32_t InitProt); |
177 | | |
178 | | void writeSection(const MCAsmLayout &Layout, const MCSection &Sec, |
179 | | uint64_t VMAddr, uint64_t FileOffset, unsigned Flags, |
180 | | uint64_t RelocationsStart, unsigned NumRelocations); |
181 | | |
182 | | void writeSymtabLoadCommand(uint32_t SymbolOffset, uint32_t NumSymbols, |
183 | | uint32_t StringTableOffset, |
184 | | uint32_t StringTableSize); |
185 | | |
186 | | void writeDysymtabLoadCommand( |
187 | | uint32_t FirstLocalSymbol, uint32_t NumLocalSymbols, |
188 | | uint32_t FirstExternalSymbol, uint32_t NumExternalSymbols, |
189 | | uint32_t FirstUndefinedSymbol, uint32_t NumUndefinedSymbols, |
190 | | uint32_t IndirectSymbolOffset, uint32_t NumIndirectSymbols); |
191 | | |
192 | | void writeNlist(MachSymbolData &MSD, const MCAsmLayout &Layout); |
193 | | |
194 | | void writeLinkeditLoadCommand(uint32_t Type, uint32_t DataOffset, |
195 | | uint32_t DataSize); |
196 | | |
197 | | void writeLinkerOptionsLoadCommand(const std::vector<std::string> &Options); |
198 | | |
199 | | // FIXME: We really need to improve the relocation validation. Basically, we |
200 | | // want to implement a separate computation which evaluates the relocation |
201 | | // entry as the linker would, and verifies that the resultant fixup value is |
202 | | // exactly what the encoder wanted. This will catch several classes of |
203 | | // problems: |
204 | | // |
205 | | // - Relocation entry bugs, the two algorithms are unlikely to have the same |
206 | | // exact bug. |
207 | | // |
208 | | // - Relaxation issues, where we forget to relax something. |
209 | | // |
210 | | // - Input errors, where something cannot be correctly encoded. 'as' allows |
211 | | // these through in many cases. |
212 | | |
213 | | // Add a relocation to be output in the object file. At the time this is |
214 | | // called, the symbol indexes are not know, so if the relocation refers |
215 | | // to a symbol it should be passed as \p RelSymbol so that it can be updated |
216 | | // afterwards. If the relocation doesn't refer to a symbol, nullptr should be |
217 | | // used. |
218 | | void addRelocation(const MCSymbol *RelSymbol, const MCSection *Sec, |
219 | 5.05M | MachO::any_relocation_info &MRE) { |
220 | 5.05M | RelAndSymbol P(RelSymbol, MRE); |
221 | 5.05M | Relocations[Sec].push_back(P); |
222 | 5.05M | } |
223 | | |
224 | | void recordScatteredRelocation(const MCAssembler &Asm, |
225 | | const MCAsmLayout &Layout, |
226 | | const MCFragment *Fragment, |
227 | | const MCFixup &Fixup, MCValue Target, |
228 | | unsigned Log2Size, uint64_t &FixedValue); |
229 | | |
230 | | void recordTLVPRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout, |
231 | | const MCFragment *Fragment, const MCFixup &Fixup, |
232 | | MCValue Target, uint64_t &FixedValue); |
233 | | |
234 | | void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout, |
235 | | const MCFragment *Fragment, const MCFixup &Fixup, |
236 | | MCValue Target, uint64_t &FixedValue) override; |
237 | | |
238 | | void bindIndirectSymbols(MCAssembler &Asm); |
239 | | |
240 | | /// Compute the symbol table data. |
241 | | void computeSymbolTable(MCAssembler &Asm, |
242 | | std::vector<MachSymbolData> &LocalSymbolData, |
243 | | std::vector<MachSymbolData> &ExternalSymbolData, |
244 | | std::vector<MachSymbolData> &UndefinedSymbolData); |
245 | | |
246 | | void computeSectionAddresses(const MCAssembler &Asm, |
247 | | const MCAsmLayout &Layout); |
248 | | |
249 | | void executePostLayoutBinding(MCAssembler &Asm, |
250 | | const MCAsmLayout &Layout) override; |
251 | | |
252 | | bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, |
253 | | const MCSymbol &A, |
254 | | const MCSymbol &B, |
255 | | bool InSet) const override; |
256 | | |
257 | | bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, |
258 | | const MCSymbol &SymA, |
259 | | const MCFragment &FB, bool InSet, |
260 | | bool IsPCRel) const override; |
261 | | |
262 | | void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override; |
263 | | }; |
264 | | |
265 | | /// Construct a new Mach-O writer instance. |
266 | | /// |
267 | | /// This routine takes ownership of the target writer subclass. |
268 | | /// |
269 | | /// \param MOTW - The target specific Mach-O writer subclass. |
270 | | /// \param OS - The stream to write to. |
271 | | /// \returns The constructed object writer. |
272 | | MCObjectWriter *createMachObjectWriter(MCMachObjectTargetWriter *MOTW, |
273 | | raw_pwrite_stream &OS, |
274 | | bool IsLittleEndian); |
275 | | |
276 | | } // end namespace llvm |
277 | | |
278 | | #endif // LLVM_MC_MCMACHOBJECTWRITER_H |