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:
MachOLinkGraphBuilder_x86_64(const object::MachOObjectFile & Obj,std::shared_ptr<orc::SymbolStringPool> SSP,SubtargetFeatures Features)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>
getRelocKind(const MachO::relocation_info & RI)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 "Unsupported x86-64 relocation: address=" +
114 formatv("{0:x8}", RI.r_address) +
115 ", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) +
116 ", kind=" + formatv("{0:x1}", RI.r_type) +
117 ", pc_rel=" + (RI.r_pcrel ? "true" : "false") +
118 ", extern=" + (RI.r_extern ? "true" : "false") +
119 ", length=" + formatv("{0:d}", 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.
parsePairRelocation(Block & BlockToFix,MachONormalizedRelocationType SubtractorKind,const MachO::relocation_info & SubRI,orc::ExecutorAddr FixupAddress,const char * FixupContent,object::relocation_iterator & UnsignedRelItr,object::relocation_iterator & RelEnd)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>("x86_64 SUBTRACTOR without paired "
141 "UNSIGNED relocation");
142
143 auto UnsignedRI = getRelocationInfo(UnsignedRelItr);
144
145 if (SubRI.r_address != UnsignedRI.r_address)
146 return make_error<JITLinkError>("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>("length of x86_64 SUBTRACTOR and paired "
151 "UNSIGNED reloc must match");
152
153 Symbol *FromSymbol;
154 if (auto FromSymbolOrErr = findSymbolByIndex(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(UnsignedRI.r_symbolnum))
172 ToSymbol = ToSymbolOrErr->GraphSymbol;
173 else
174 return ToSymbolOrErr.takeError();
175 } else {
176 auto ToSymbolSec = findSectionByIndex(UnsignedRI.r_symbolnum - 1);
177 if (!ToSymbolSec)
178 return ToSymbolSec.takeError();
179 ToSymbol = getSymbolByAddress(*ToSymbolSec, 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>("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
addRelocations()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>("Virtual section contains "
241 "relocations");
242 continue;
243 }
244
245 auto NSec =
246 findSectionByIndex(Obj.getSectionIndex(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, 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 "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(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(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(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>("GOTLD at invalid offset " +
334 formatv("{0}", FixupOffset));
335 break;
336 case MachOPCRel32GOT:
337 if (auto TargetSymbolOrErr = findSymbolByIndex(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(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>("TLV at invalid offset " +
353 formatv("{0}", FixupOffset));
354 break;
355 case MachOPointer32:
356 if (auto TargetSymbolOrErr = findSymbolByIndex(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(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(RI.r_symbolnum - 1);
374 if (!TargetNSec)
375 return TargetNSec.takeError();
376 if (auto TargetSymbolOrErr =
377 findSymbolByAddress(*TargetNSec, 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(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(RI.r_symbolnum - 1);
399 if (!TargetNSec)
400 return TargetNSec.takeError();
401 if (auto TargetSymbolOrErr =
402 findSymbolByAddress(*TargetNSec, 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(RI.r_symbolnum - 1);
419 if (!TargetNSec)
420 return TargetNSec.takeError();
421 if (auto TargetSymbolOrErr =
422 findSymbolByAddress(*TargetNSec, 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, *MachORelocKind, RI,
439 FixupAddress, FixupContent, ++RelItr, RelEnd);
440 if (!PairInfo)
441 return PairInfo.takeError();
442 std::tie(Kind, TargetSymbol, 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(Kind, FixupAddress - BlockToFix->getAddress(),
456 *TargetSymbol, Addend);
457 }
458 }
459 return Error::success();
460 }
461 };
462
buildGOTAndStubs_MachO_x86_64(LinkGraph & G)463 Error buildGOTAndStubs_MachO_x86_64(LinkGraph &G) {
464 x86_64::GOTTableManager GOT(G);
465 x86_64::PLTTableManager PLT(G, GOT);
466 visitExistingEdges(G, GOT, 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:
MachOJITLinker_x86_64(std::unique_ptr<JITLinkContext> Ctx,std::unique_ptr<LinkGraph> G,PassConfiguration PassConfig)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:
applyFixup(LinkGraph & G,Block & B,const Edge & E) const485 Error applyFixup(LinkGraph &G, Block &B, const Edge &E) const {
486 return x86_64::applyFixup(G, B, E, nullptr);
487 }
488 };
489
createLinkGraphFromMachOObject_x86_64(MemoryBufferRef ObjectBuffer,std::shared_ptr<orc::SymbolStringPool> SSP)490 Expected<std::unique_ptr<LinkGraph>> createLinkGraphFromMachOObject_x86_64(
491 MemoryBufferRef ObjectBuffer, std::shared_ptr<orc::SymbolStringPool> SSP) {
492 auto MachOObj = object::ObjectFile::createMachOObjectFile(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
encodingSpecifiesDWARFllvm::jitlink::CompactUnwindTraits_MachO_x86_64519 static bool encodingSpecifiesDWARF(uint32_t Encoding) {
520 constexpr uint32_t DWARFMode = 0x04000000;
521 return (Encoding & EncodingModeMask) == DWARFMode;
522 }
523
encodingCannotBeMergedllvm::jitlink::CompactUnwindTraits_MachO_x86_64524 static bool encodingCannotBeMerged(uint32_t Encoding) {
525 constexpr uint32_t StackIndirectMode = 0x03000000;
526 return (Encoding & EncodingModeMask) == StackIndirectMode;
527 }
528 };
529
link_MachO_x86_64(std::unique_ptr<LinkGraph> G,std::unique_ptr<JITLinkContext> Ctx)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(G->getTargetTriple())) {
536 // Add a mark-live pass.
537 if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple()))
538 Config.PrePrunePasses.push_back(std::move(MarkLive));
539 else
540 Config.PrePrunePasses.push_back(markAllSymbolsLive);
541
542 // Add eh-frame passes.
543 Config.PrePrunePasses.push_back(createEHFrameSplitterPass_MachO_x86_64());
544 Config.PrePrunePasses.push_back(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 orc::MachOCompactUnwindSectionName, orc::MachOUnwindInfoSectionName,
550 orc::MachOEHFrameSectionName);
551
552 // Add compact unwind prepare pass.
553 Config.PrePrunePasses.push_back([CompactUnwindMgr](LinkGraph &G) {
554 return CompactUnwindMgr->prepareForPrune(G);
555 });
556
557 // Resolve any external section start / end symbols.
558 Config.PostAllocationPasses.push_back(
559 createDefineExternalSectionStartAndEndSymbolsPass(
560 identifyMachOSectionStartAndEndSymbols));
561
562 // Add an in-place GOT/Stubs pass.
563 Config.PostPrunePasses.push_back(buildGOTAndStubs_MachO_x86_64);
564
565 // Reserve space for unwind-info.
566 Config.PostPrunePasses.push_back([CompactUnwindMgr](LinkGraph &G) {
567 return CompactUnwindMgr->processAndReserveUnwindInfo(G);
568 });
569
570 // Translate compact-unwind to unwind-info.
571 Config.PreFixupPasses.push_back([CompactUnwindMgr](LinkGraph &G) {
572 return CompactUnwindMgr->writeUnwindInfo(G);
573 });
574
575 // Add GOT/Stubs optimizer pass.
576 Config.PreFixupPasses.push_back(x86_64::optimizeGOTAndStubAccesses);
577 }
578
579 if (auto Err = Ctx->modifyPassConfig(*G, Config))
580 return Ctx->notifyFailed(std::move(Err));
581
582 // Construct a JITLinker and run the link function.
583 MachOJITLinker_x86_64::link(std::move(Ctx), std::move(G), std::move(Config));
584 }
585
createEHFrameSplitterPass_MachO_x86_64()586 LinkGraphPassFunction createEHFrameSplitterPass_MachO_x86_64() {
587 return DWARFRecordSectionSplitter(orc::MachOEHFrameSectionName);
588 }
589
createEHFrameEdgeFixerPass_MachO_x86_64()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