1 | //===---- MachO_x86_64.cpp -JIT linker implementation for MachO/x86-64 ----===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // MachO/x86-64 jit-link implementation. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #include "llvm/ExecutionEngine/JITLink/MachO_x86_64.h" |
14 | #include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h" |
15 | #include "llvm/ExecutionEngine/JITLink/x86_64.h" |
16 | #include "llvm/ExecutionEngine/Orc/Shared/MachOObjectFormat.h" |
17 | |
18 | #include "CompactUnwindSupport.h" |
19 | #include "DefineExternalSectionStartAndEndSymbols.h" |
20 | #include "MachOLinkGraphBuilder.h" |
21 | |
22 | #define DEBUG_TYPE "jitlink" |
23 | |
24 | using namespace llvm; |
25 | using namespace llvm::jitlink; |
26 | |
27 | namespace { |
28 | |
29 | class MachOLinkGraphBuilder_x86_64 : public MachOLinkGraphBuilder { |
30 | public: |
31 | MachOLinkGraphBuilder_x86_64(const object::MachOObjectFile &Obj, |
32 | std::shared_ptr<orc::SymbolStringPool> SSP, |
33 | SubtargetFeatures Features) |
34 | : MachOLinkGraphBuilder(Obj, std::move(SSP), |
35 | Triple("x86_64-apple-darwin" ), |
36 | std::move(Features), x86_64::getEdgeKindName) {} |
37 | |
38 | private: |
39 | enum MachONormalizedRelocationType : unsigned { |
40 | MachOBranch32, |
41 | MachOPointer32, |
42 | MachOPointer64, |
43 | MachOPointer64Anon, |
44 | MachOPCRel32, |
45 | MachOPCRel32Minus1, |
46 | MachOPCRel32Minus2, |
47 | MachOPCRel32Minus4, |
48 | MachOPCRel32Anon, |
49 | MachOPCRel32Minus1Anon, |
50 | MachOPCRel32Minus2Anon, |
51 | MachOPCRel32Minus4Anon, |
52 | MachOPCRel32GOTLoad, |
53 | MachOPCRel32GOT, |
54 | MachOPCRel32TLV, |
55 | MachOSubtractor32, |
56 | MachOSubtractor64, |
57 | }; |
58 | |
59 | static Expected<MachONormalizedRelocationType> |
60 | getRelocKind(const MachO::relocation_info &RI) { |
61 | switch (RI.r_type) { |
62 | case MachO::X86_64_RELOC_UNSIGNED: |
63 | if (!RI.r_pcrel) { |
64 | if (RI.r_length == 3) |
65 | return RI.r_extern ? MachOPointer64 : MachOPointer64Anon; |
66 | else if (RI.r_extern && RI.r_length == 2) |
67 | return MachOPointer32; |
68 | } |
69 | break; |
70 | case MachO::X86_64_RELOC_SIGNED: |
71 | if (RI.r_pcrel && RI.r_length == 2) |
72 | return RI.r_extern ? MachOPCRel32 : MachOPCRel32Anon; |
73 | break; |
74 | case MachO::X86_64_RELOC_BRANCH: |
75 | if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) |
76 | return MachOBranch32; |
77 | break; |
78 | case MachO::X86_64_RELOC_GOT_LOAD: |
79 | if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) |
80 | return MachOPCRel32GOTLoad; |
81 | break; |
82 | case MachO::X86_64_RELOC_GOT: |
83 | if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) |
84 | return MachOPCRel32GOT; |
85 | break; |
86 | case MachO::X86_64_RELOC_SUBTRACTOR: |
87 | if (!RI.r_pcrel && RI.r_extern) { |
88 | if (RI.r_length == 2) |
89 | return MachOSubtractor32; |
90 | else if (RI.r_length == 3) |
91 | return MachOSubtractor64; |
92 | } |
93 | break; |
94 | case MachO::X86_64_RELOC_SIGNED_1: |
95 | if (RI.r_pcrel && RI.r_length == 2) |
96 | return RI.r_extern ? MachOPCRel32Minus1 : MachOPCRel32Minus1Anon; |
97 | break; |
98 | case MachO::X86_64_RELOC_SIGNED_2: |
99 | if (RI.r_pcrel && RI.r_length == 2) |
100 | return RI.r_extern ? MachOPCRel32Minus2 : MachOPCRel32Minus2Anon; |
101 | break; |
102 | case MachO::X86_64_RELOC_SIGNED_4: |
103 | if (RI.r_pcrel && RI.r_length == 2) |
104 | return RI.r_extern ? MachOPCRel32Minus4 : MachOPCRel32Minus4Anon; |
105 | break; |
106 | case MachO::X86_64_RELOC_TLV: |
107 | if (RI.r_pcrel && RI.r_extern && RI.r_length == 2) |
108 | return MachOPCRel32TLV; |
109 | break; |
110 | } |
111 | |
112 | return make_error<JITLinkError>( |
113 | Args: "Unsupported x86-64 relocation: address=" + |
114 | formatv(Fmt: "{0:x8}" , Vals: RI.r_address) + |
115 | ", symbolnum=" + formatv(Fmt: "{0:x6}" , Vals: RI.r_symbolnum) + |
116 | ", kind=" + formatv(Fmt: "{0:x1}" , Vals: RI.r_type) + |
117 | ", pc_rel=" + (RI.r_pcrel ? "true" : "false" ) + |
118 | ", extern=" + (RI.r_extern ? "true" : "false" ) + |
119 | ", length=" + formatv(Fmt: "{0:d}" , Vals: RI.r_length)); |
120 | } |
121 | |
122 | using PairRelocInfo = std::tuple<Edge::Kind, Symbol *, uint64_t>; |
123 | |
124 | // Parses paired SUBTRACTOR/UNSIGNED relocations and, on success, |
125 | // returns the edge kind and addend to be used. |
126 | Expected<PairRelocInfo> parsePairRelocation( |
127 | Block &BlockToFix, MachONormalizedRelocationType SubtractorKind, |
128 | const MachO::relocation_info &SubRI, orc::ExecutorAddr FixupAddress, |
129 | const char *FixupContent, object::relocation_iterator &UnsignedRelItr, |
130 | object::relocation_iterator &RelEnd) { |
131 | using namespace support; |
132 | |
133 | assert(((SubtractorKind == MachOSubtractor32 && SubRI.r_length == 2) || |
134 | (SubtractorKind == MachOSubtractor64 && SubRI.r_length == 3)) && |
135 | "Subtractor kind should match length" ); |
136 | assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern" ); |
137 | assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel" ); |
138 | |
139 | if (UnsignedRelItr == RelEnd) |
140 | return make_error<JITLinkError>(Args: "x86_64 SUBTRACTOR without paired " |
141 | "UNSIGNED relocation" ); |
142 | |
143 | auto UnsignedRI = getRelocationInfo(RelItr: UnsignedRelItr); |
144 | |
145 | if (SubRI.r_address != UnsignedRI.r_address) |
146 | return make_error<JITLinkError>(Args: "x86_64 SUBTRACTOR and paired UNSIGNED " |
147 | "point to different addresses" ); |
148 | |
149 | if (SubRI.r_length != UnsignedRI.r_length) |
150 | return make_error<JITLinkError>(Args: "length of x86_64 SUBTRACTOR and paired " |
151 | "UNSIGNED reloc must match" ); |
152 | |
153 | Symbol *FromSymbol; |
154 | if (auto FromSymbolOrErr = findSymbolByIndex(Index: SubRI.r_symbolnum)) |
155 | FromSymbol = FromSymbolOrErr->GraphSymbol; |
156 | else |
157 | return FromSymbolOrErr.takeError(); |
158 | |
159 | // Read the current fixup value. |
160 | uint64_t FixupValue = 0; |
161 | if (SubRI.r_length == 3) |
162 | FixupValue = *(const little64_t *)FixupContent; |
163 | else |
164 | FixupValue = *(const little32_t *)FixupContent; |
165 | |
166 | // Find 'ToSymbol' using symbol number or address, depending on whether the |
167 | // paired UNSIGNED relocation is extern. |
168 | Symbol *ToSymbol = nullptr; |
169 | if (UnsignedRI.r_extern) { |
170 | // Find target symbol by symbol index. |
171 | if (auto ToSymbolOrErr = findSymbolByIndex(Index: UnsignedRI.r_symbolnum)) |
172 | ToSymbol = ToSymbolOrErr->GraphSymbol; |
173 | else |
174 | return ToSymbolOrErr.takeError(); |
175 | } else { |
176 | auto ToSymbolSec = findSectionByIndex(Index: UnsignedRI.r_symbolnum - 1); |
177 | if (!ToSymbolSec) |
178 | return ToSymbolSec.takeError(); |
179 | ToSymbol = getSymbolByAddress(NSec&: *ToSymbolSec, Address: ToSymbolSec->Address); |
180 | assert(ToSymbol && "No symbol for section" ); |
181 | FixupValue -= ToSymbol->getAddress().getValue(); |
182 | } |
183 | |
184 | Edge::Kind DeltaKind; |
185 | Symbol *TargetSymbol; |
186 | uint64_t Addend; |
187 | |
188 | bool FixingFromSymbol = true; |
189 | if (&BlockToFix == &FromSymbol->getAddressable()) { |
190 | if (LLVM_UNLIKELY(&BlockToFix == &ToSymbol->getAddressable())) { |
191 | // From and To are symbols in the same block. Decide direction by offset |
192 | // instead. |
193 | if (ToSymbol->getAddress() > FixupAddress) |
194 | FixingFromSymbol = true; |
195 | else if (FromSymbol->getAddress() > FixupAddress) |
196 | FixingFromSymbol = false; |
197 | else |
198 | FixingFromSymbol = FromSymbol->getAddress() >= ToSymbol->getAddress(); |
199 | } else |
200 | FixingFromSymbol = true; |
201 | } else { |
202 | if (&BlockToFix == &ToSymbol->getAddressable()) |
203 | FixingFromSymbol = false; |
204 | else { |
205 | // BlockToFix was neither FromSymbol nor ToSymbol. |
206 | return make_error<JITLinkError>(Args: "SUBTRACTOR relocation must fix up " |
207 | "either 'A' or 'B' (or a symbol in one " |
208 | "of their alt-entry groups)" ); |
209 | } |
210 | } |
211 | |
212 | if (FixingFromSymbol) { |
213 | TargetSymbol = ToSymbol; |
214 | DeltaKind = (SubRI.r_length == 3) ? x86_64::Delta64 : x86_64::Delta32; |
215 | Addend = FixupValue + (FixupAddress - FromSymbol->getAddress()); |
216 | // FIXME: handle extern 'from'. |
217 | } else { |
218 | TargetSymbol = FromSymbol; |
219 | DeltaKind = |
220 | (SubRI.r_length == 3) ? x86_64::NegDelta64 : x86_64::NegDelta32; |
221 | Addend = FixupValue - (FixupAddress - ToSymbol->getAddress()); |
222 | } |
223 | |
224 | return PairRelocInfo(DeltaKind, TargetSymbol, Addend); |
225 | } |
226 | |
227 | Error addRelocations() override { |
228 | using namespace support; |
229 | auto &Obj = getObject(); |
230 | |
231 | LLVM_DEBUG(dbgs() << "Processing relocations:\n" ); |
232 | |
233 | for (const auto &S : Obj.sections()) { |
234 | |
235 | orc::ExecutorAddr SectionAddress(S.getAddress()); |
236 | |
237 | // Skip relocations virtual sections. |
238 | if (S.isVirtual()) { |
239 | if (S.relocation_begin() != S.relocation_end()) |
240 | return make_error<JITLinkError>(Args: "Virtual section contains " |
241 | "relocations" ); |
242 | continue; |
243 | } |
244 | |
245 | auto NSec = |
246 | findSectionByIndex(Index: Obj.getSectionIndex(Sec: S.getRawDataRefImpl())); |
247 | if (!NSec) |
248 | return NSec.takeError(); |
249 | |
250 | // Skip relocations for MachO sections without corresponding graph |
251 | // sections. |
252 | { |
253 | if (!NSec->GraphSection) { |
254 | LLVM_DEBUG({ |
255 | dbgs() << " Skipping relocations for MachO section " |
256 | << NSec->SegName << "/" << NSec->SectName |
257 | << " which has no associated graph section\n" ; |
258 | }); |
259 | continue; |
260 | } |
261 | } |
262 | |
263 | // Add relocations for section. |
264 | for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end(); |
265 | RelItr != RelEnd; ++RelItr) { |
266 | |
267 | MachO::relocation_info RI = getRelocationInfo(RelItr); |
268 | |
269 | // Find the address of the value to fix up. |
270 | auto FixupAddress = SectionAddress + (uint32_t)RI.r_address; |
271 | |
272 | LLVM_DEBUG({ |
273 | dbgs() << " " << NSec->SectName << " + " |
274 | << formatv("{0:x8}" , RI.r_address) << ":\n" ; |
275 | }); |
276 | |
277 | // Find the block that the fixup points to. |
278 | Block *BlockToFix = nullptr; |
279 | { |
280 | auto SymbolToFixOrErr = findSymbolByAddress(NSec&: *NSec, Address: FixupAddress); |
281 | if (!SymbolToFixOrErr) |
282 | return SymbolToFixOrErr.takeError(); |
283 | BlockToFix = &SymbolToFixOrErr->getBlock(); |
284 | } |
285 | |
286 | if (FixupAddress + orc::ExecutorAddrDiff(1ULL << RI.r_length) > |
287 | BlockToFix->getAddress() + BlockToFix->getContent().size()) |
288 | return make_error<JITLinkError>( |
289 | Args: "Relocation extends past end of fixup block" ); |
290 | |
291 | // Get a pointer to the fixup content. |
292 | const char *FixupContent = BlockToFix->getContent().data() + |
293 | (FixupAddress - BlockToFix->getAddress()); |
294 | |
295 | size_t FixupOffset = FixupAddress - BlockToFix->getAddress(); |
296 | |
297 | // The target symbol and addend will be populated by the switch below. |
298 | Symbol *TargetSymbol = nullptr; |
299 | uint64_t Addend = 0; |
300 | |
301 | // Validate the relocation kind. |
302 | auto MachORelocKind = getRelocKind(RI); |
303 | if (!MachORelocKind) |
304 | return MachORelocKind.takeError(); |
305 | |
306 | Edge::Kind Kind = Edge::Invalid; |
307 | |
308 | switch (*MachORelocKind) { |
309 | case MachOBranch32: |
310 | if (auto TargetSymbolOrErr = findSymbolByIndex(Index: RI.r_symbolnum)) |
311 | TargetSymbol = TargetSymbolOrErr->GraphSymbol; |
312 | else |
313 | return TargetSymbolOrErr.takeError(); |
314 | Addend = *(const little32_t *)FixupContent; |
315 | Kind = x86_64::BranchPCRel32; |
316 | break; |
317 | case MachOPCRel32: |
318 | if (auto TargetSymbolOrErr = findSymbolByIndex(Index: RI.r_symbolnum)) |
319 | TargetSymbol = TargetSymbolOrErr->GraphSymbol; |
320 | else |
321 | return TargetSymbolOrErr.takeError(); |
322 | Addend = *(const little32_t *)FixupContent - 4; |
323 | Kind = x86_64::Delta32; |
324 | break; |
325 | case MachOPCRel32GOTLoad: |
326 | if (auto TargetSymbolOrErr = findSymbolByIndex(Index: RI.r_symbolnum)) |
327 | TargetSymbol = TargetSymbolOrErr->GraphSymbol; |
328 | else |
329 | return TargetSymbolOrErr.takeError(); |
330 | Addend = *(const little32_t *)FixupContent; |
331 | Kind = x86_64::RequestGOTAndTransformToPCRel32GOTLoadREXRelaxable; |
332 | if (FixupOffset < 3) |
333 | return make_error<JITLinkError>(Args: "GOTLD at invalid offset " + |
334 | formatv(Fmt: "{0}" , Vals&: FixupOffset)); |
335 | break; |
336 | case MachOPCRel32GOT: |
337 | if (auto TargetSymbolOrErr = findSymbolByIndex(Index: RI.r_symbolnum)) |
338 | TargetSymbol = TargetSymbolOrErr->GraphSymbol; |
339 | else |
340 | return TargetSymbolOrErr.takeError(); |
341 | Addend = *(const little32_t *)FixupContent - 4; |
342 | Kind = x86_64::RequestGOTAndTransformToDelta32; |
343 | break; |
344 | case MachOPCRel32TLV: |
345 | if (auto TargetSymbolOrErr = findSymbolByIndex(Index: RI.r_symbolnum)) |
346 | TargetSymbol = TargetSymbolOrErr->GraphSymbol; |
347 | else |
348 | return TargetSymbolOrErr.takeError(); |
349 | Addend = *(const little32_t *)FixupContent; |
350 | Kind = x86_64::RequestTLVPAndTransformToPCRel32TLVPLoadREXRelaxable; |
351 | if (FixupOffset < 3) |
352 | return make_error<JITLinkError>(Args: "TLV at invalid offset " + |
353 | formatv(Fmt: "{0}" , Vals&: FixupOffset)); |
354 | break; |
355 | case MachOPointer32: |
356 | if (auto TargetSymbolOrErr = findSymbolByIndex(Index: RI.r_symbolnum)) |
357 | TargetSymbol = TargetSymbolOrErr->GraphSymbol; |
358 | else |
359 | return TargetSymbolOrErr.takeError(); |
360 | Addend = *(const ulittle32_t *)FixupContent; |
361 | Kind = x86_64::Pointer32; |
362 | break; |
363 | case MachOPointer64: |
364 | if (auto TargetSymbolOrErr = findSymbolByIndex(Index: RI.r_symbolnum)) |
365 | TargetSymbol = TargetSymbolOrErr->GraphSymbol; |
366 | else |
367 | return TargetSymbolOrErr.takeError(); |
368 | Addend = *(const ulittle64_t *)FixupContent; |
369 | Kind = x86_64::Pointer64; |
370 | break; |
371 | case MachOPointer64Anon: { |
372 | orc::ExecutorAddr TargetAddress(*(const ulittle64_t *)FixupContent); |
373 | auto TargetNSec = findSectionByIndex(Index: RI.r_symbolnum - 1); |
374 | if (!TargetNSec) |
375 | return TargetNSec.takeError(); |
376 | if (auto TargetSymbolOrErr = |
377 | findSymbolByAddress(NSec&: *TargetNSec, Address: TargetAddress)) |
378 | TargetSymbol = &*TargetSymbolOrErr; |
379 | else |
380 | return TargetSymbolOrErr.takeError(); |
381 | Addend = TargetAddress - TargetSymbol->getAddress(); |
382 | Kind = x86_64::Pointer64; |
383 | break; |
384 | } |
385 | case MachOPCRel32Minus1: |
386 | case MachOPCRel32Minus2: |
387 | case MachOPCRel32Minus4: |
388 | if (auto TargetSymbolOrErr = findSymbolByIndex(Index: RI.r_symbolnum)) |
389 | TargetSymbol = TargetSymbolOrErr->GraphSymbol; |
390 | else |
391 | return TargetSymbolOrErr.takeError(); |
392 | Addend = *(const little32_t *)FixupContent - 4; |
393 | Kind = x86_64::Delta32; |
394 | break; |
395 | case MachOPCRel32Anon: { |
396 | orc::ExecutorAddr TargetAddress(FixupAddress + 4 + |
397 | *(const little32_t *)FixupContent); |
398 | auto TargetNSec = findSectionByIndex(Index: RI.r_symbolnum - 1); |
399 | if (!TargetNSec) |
400 | return TargetNSec.takeError(); |
401 | if (auto TargetSymbolOrErr = |
402 | findSymbolByAddress(NSec&: *TargetNSec, Address: TargetAddress)) |
403 | TargetSymbol = &*TargetSymbolOrErr; |
404 | else |
405 | return TargetSymbolOrErr.takeError(); |
406 | Addend = TargetAddress - TargetSymbol->getAddress() - 4; |
407 | Kind = x86_64::Delta32; |
408 | break; |
409 | } |
410 | case MachOPCRel32Minus1Anon: |
411 | case MachOPCRel32Minus2Anon: |
412 | case MachOPCRel32Minus4Anon: { |
413 | orc::ExecutorAddrDiff Delta = |
414 | 4 + orc::ExecutorAddrDiff( |
415 | 1ULL << (*MachORelocKind - MachOPCRel32Minus1Anon)); |
416 | orc::ExecutorAddr TargetAddress = |
417 | FixupAddress + Delta + *(const little32_t *)FixupContent; |
418 | auto TargetNSec = findSectionByIndex(Index: RI.r_symbolnum - 1); |
419 | if (!TargetNSec) |
420 | return TargetNSec.takeError(); |
421 | if (auto TargetSymbolOrErr = |
422 | findSymbolByAddress(NSec&: *TargetNSec, Address: TargetAddress)) |
423 | TargetSymbol = &*TargetSymbolOrErr; |
424 | else |
425 | return TargetSymbolOrErr.takeError(); |
426 | Addend = TargetAddress - TargetSymbol->getAddress() - Delta; |
427 | Kind = x86_64::Delta32; |
428 | break; |
429 | } |
430 | case MachOSubtractor32: |
431 | case MachOSubtractor64: { |
432 | // We use Delta32/Delta64 to represent SUBTRACTOR relocations. |
433 | // parsePairRelocation handles the paired reloc, and returns the |
434 | // edge kind to be used (either Delta32/Delta64, or |
435 | // NegDelta32/NegDelta64, depending on the direction of the |
436 | // subtraction) along with the addend. |
437 | auto PairInfo = |
438 | parsePairRelocation(BlockToFix&: *BlockToFix, SubtractorKind: *MachORelocKind, SubRI: RI, |
439 | FixupAddress, FixupContent, UnsignedRelItr&: ++RelItr, RelEnd); |
440 | if (!PairInfo) |
441 | return PairInfo.takeError(); |
442 | std::tie(args&: Kind, args&: TargetSymbol, args&: Addend) = *PairInfo; |
443 | assert(TargetSymbol && "No target symbol from parsePairRelocation?" ); |
444 | break; |
445 | } |
446 | } |
447 | |
448 | LLVM_DEBUG({ |
449 | dbgs() << " " ; |
450 | Edge GE(Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol, |
451 | Addend); |
452 | printEdge(dbgs(), *BlockToFix, GE, x86_64::getEdgeKindName(Kind)); |
453 | dbgs() << "\n" ; |
454 | }); |
455 | BlockToFix->addEdge(K: Kind, Offset: FixupAddress - BlockToFix->getAddress(), |
456 | Target&: *TargetSymbol, Addend); |
457 | } |
458 | } |
459 | return Error::success(); |
460 | } |
461 | }; |
462 | |
463 | Error buildGOTAndStubs_MachO_x86_64(LinkGraph &G) { |
464 | x86_64::GOTTableManager GOT(G); |
465 | x86_64::PLTTableManager PLT(G, GOT); |
466 | visitExistingEdges(G, Vs&: GOT, Vs&: PLT); |
467 | return Error::success(); |
468 | } |
469 | |
470 | } // namespace |
471 | |
472 | namespace llvm { |
473 | namespace jitlink { |
474 | |
475 | class MachOJITLinker_x86_64 : public JITLinker<MachOJITLinker_x86_64> { |
476 | friend class JITLinker<MachOJITLinker_x86_64>; |
477 | |
478 | public: |
479 | MachOJITLinker_x86_64(std::unique_ptr<JITLinkContext> Ctx, |
480 | std::unique_ptr<LinkGraph> G, |
481 | PassConfiguration PassConfig) |
482 | : JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {} |
483 | |
484 | private: |
485 | Error applyFixup(LinkGraph &G, Block &B, const Edge &E) const { |
486 | return x86_64::applyFixup(G, B, E, GOTSymbol: nullptr); |
487 | } |
488 | }; |
489 | |
490 | Expected<std::unique_ptr<LinkGraph>> createLinkGraphFromMachOObject_x86_64( |
491 | MemoryBufferRef ObjectBuffer, std::shared_ptr<orc::SymbolStringPool> SSP) { |
492 | auto MachOObj = object::ObjectFile::createMachOObjectFile(Object: ObjectBuffer); |
493 | if (!MachOObj) |
494 | return MachOObj.takeError(); |
495 | |
496 | auto Features = (*MachOObj)->getFeatures(); |
497 | if (!Features) |
498 | return Features.takeError(); |
499 | |
500 | return MachOLinkGraphBuilder_x86_64(**MachOObj, std::move(SSP), |
501 | std::move(*Features)) |
502 | .buildGraph(); |
503 | } |
504 | |
505 | struct CompactUnwindTraits_MachO_x86_64 |
506 | : public CompactUnwindTraits<CompactUnwindTraits_MachO_x86_64, |
507 | /* PointerSize = */ 8> { |
508 | // FIXME: Reinstate once we no longer need the MSVC workaround. See |
509 | // FIXME for CompactUnwindTraits in CompactUnwindSupport.h. |
510 | // constexpr static size_t PointerSize = 8; |
511 | |
512 | constexpr static endianness Endianness = endianness::little; |
513 | |
514 | constexpr static uint32_t EncodingModeMask = 0x0f000000; |
515 | constexpr static uint32_t DWARFSectionOffsetMask = 0x00ffffff; |
516 | |
517 | using GOTManager = x86_64::GOTTableManager; |
518 | |
519 | static bool encodingSpecifiesDWARF(uint32_t Encoding) { |
520 | constexpr uint32_t DWARFMode = 0x04000000; |
521 | return (Encoding & EncodingModeMask) == DWARFMode; |
522 | } |
523 | |
524 | static bool encodingCannotBeMerged(uint32_t Encoding) { |
525 | constexpr uint32_t StackIndirectMode = 0x03000000; |
526 | return (Encoding & EncodingModeMask) == StackIndirectMode; |
527 | } |
528 | }; |
529 | |
530 | void link_MachO_x86_64(std::unique_ptr<LinkGraph> G, |
531 | std::unique_ptr<JITLinkContext> Ctx) { |
532 | |
533 | PassConfiguration Config; |
534 | |
535 | if (Ctx->shouldAddDefaultTargetPasses(TT: G->getTargetTriple())) { |
536 | // Add a mark-live pass. |
537 | if (auto MarkLive = Ctx->getMarkLivePass(TT: G->getTargetTriple())) |
538 | Config.PrePrunePasses.push_back(x: std::move(MarkLive)); |
539 | else |
540 | Config.PrePrunePasses.push_back(x: markAllSymbolsLive); |
541 | |
542 | // Add eh-frame passes. |
543 | Config.PrePrunePasses.push_back(x: createEHFrameSplitterPass_MachO_x86_64()); |
544 | Config.PrePrunePasses.push_back(x: createEHFrameEdgeFixerPass_MachO_x86_64()); |
545 | |
546 | // Create a compact-unwind manager for use in passes below. |
547 | auto CompactUnwindMgr = std::make_shared< |
548 | CompactUnwindManager<CompactUnwindTraits_MachO_x86_64>>( |
549 | args&: orc::MachOCompactUnwindSectionName, args&: orc::MachOUnwindInfoSectionName, |
550 | args&: orc::MachOEHFrameSectionName); |
551 | |
552 | // Add compact unwind prepare pass. |
553 | Config.PrePrunePasses.push_back(x: [CompactUnwindMgr](LinkGraph &G) { |
554 | return CompactUnwindMgr->prepareForPrune(G); |
555 | }); |
556 | |
557 | // Resolve any external section start / end symbols. |
558 | Config.PostAllocationPasses.push_back( |
559 | x: createDefineExternalSectionStartAndEndSymbolsPass( |
560 | F&: identifyMachOSectionStartAndEndSymbols)); |
561 | |
562 | // Add an in-place GOT/Stubs pass. |
563 | Config.PostPrunePasses.push_back(x: buildGOTAndStubs_MachO_x86_64); |
564 | |
565 | // Reserve space for unwind-info. |
566 | Config.PostPrunePasses.push_back(x: [CompactUnwindMgr](LinkGraph &G) { |
567 | return CompactUnwindMgr->processAndReserveUnwindInfo(G); |
568 | }); |
569 | |
570 | // Translate compact-unwind to unwind-info. |
571 | Config.PreFixupPasses.push_back(x: [CompactUnwindMgr](LinkGraph &G) { |
572 | return CompactUnwindMgr->writeUnwindInfo(G); |
573 | }); |
574 | |
575 | // Add GOT/Stubs optimizer pass. |
576 | Config.PreFixupPasses.push_back(x: x86_64::optimizeGOTAndStubAccesses); |
577 | } |
578 | |
579 | if (auto Err = Ctx->modifyPassConfig(G&: *G, Config)) |
580 | return Ctx->notifyFailed(Err: std::move(Err)); |
581 | |
582 | // Construct a JITLinker and run the link function. |
583 | MachOJITLinker_x86_64::link(Args: std::move(Ctx), Args: std::move(G), Args: std::move(Config)); |
584 | } |
585 | |
586 | LinkGraphPassFunction createEHFrameSplitterPass_MachO_x86_64() { |
587 | return DWARFRecordSectionSplitter(orc::MachOEHFrameSectionName); |
588 | } |
589 | |
590 | LinkGraphPassFunction createEHFrameEdgeFixerPass_MachO_x86_64() { |
591 | return EHFrameEdgeFixer(orc::MachOEHFrameSectionName, x86_64::PointerSize, |
592 | x86_64::Pointer32, x86_64::Pointer64, x86_64::Delta32, |
593 | x86_64::Delta64, x86_64::NegDelta32); |
594 | } |
595 | |
596 | } // end namespace jitlink |
597 | } // end namespace llvm |
598 | |