xref: /llvm-project/bolt/lib/Rewrite/MachORewriteInstance.cpp (revision 15d82c62dcd7ba1bff6b62c2efaeeeac1187760f)
1 //===- bolt/Rewrite/MachORewriteInstance.cpp - MachO rewriter -------------===//
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 #include "bolt/Rewrite/MachORewriteInstance.h"
10 #include "bolt/Core/BinaryContext.h"
11 #include "bolt/Core/BinaryEmitter.h"
12 #include "bolt/Core/BinaryFunction.h"
13 #include "bolt/Core/JumpTable.h"
14 #include "bolt/Core/MCPlusBuilder.h"
15 #include "bolt/Passes/Instrumentation.h"
16 #include "bolt/Passes/PatchEntries.h"
17 #include "bolt/Profile/DataReader.h"
18 #include "bolt/Rewrite/BinaryPassManager.h"
19 #include "bolt/Rewrite/ExecutableFileMemoryManager.h"
20 #include "bolt/RuntimeLibs/InstrumentationRuntimeLibrary.h"
21 #include "bolt/Utils/Utils.h"
22 #include "llvm/MC/MCAsmLayout.h"
23 #include "llvm/MC/MCObjectStreamer.h"
24 #include "llvm/Support/Errc.h"
25 #include "llvm/Support/FileSystem.h"
26 #include "llvm/Support/ToolOutputFile.h"
27 #include <memory>
28 
29 namespace opts {
30 
31 using namespace llvm;
32 extern cl::opt<unsigned> AlignText;
33 //FIXME! Upstream change
34 //extern cl::opt<bool> CheckOverlappingElements;
35 extern cl::opt<bool> ForcePatch;
36 extern cl::opt<bool> Instrument;
37 extern cl::opt<bool> InstrumentCalls;
38 extern cl::opt<bolt::JumpTableSupportLevel> JumpTables;
39 extern cl::opt<bool> KeepTmp;
40 extern cl::opt<bool> NeverPrint;
41 extern cl::opt<std::string> OutputFilename;
42 extern cl::opt<bool> PrintAfterBranchFixup;
43 extern cl::opt<bool> PrintFinalized;
44 extern cl::opt<bool> PrintNormalized;
45 extern cl::opt<bool> PrintReordered;
46 extern cl::opt<bool> PrintSections;
47 extern cl::opt<bool> PrintDisasm;
48 extern cl::opt<bool> PrintCFG;
49 extern cl::opt<std::string> RuntimeInstrumentationLib;
50 extern cl::opt<unsigned> Verbosity;
51 } // namespace opts
52 
53 namespace llvm {
54 namespace bolt {
55 
56 extern MCPlusBuilder *createX86MCPlusBuilder(const MCInstrAnalysis *,
57                                              const MCInstrInfo *,
58                                              const MCRegisterInfo *);
59 extern MCPlusBuilder *createAArch64MCPlusBuilder(const MCInstrAnalysis *,
60                                                  const MCInstrInfo *,
61                                                  const MCRegisterInfo *);
62 
63 namespace {
64 
65 MCPlusBuilder *createMCPlusBuilder(const Triple::ArchType Arch,
66                                    const MCInstrAnalysis *Analysis,
67                                    const MCInstrInfo *Info,
68                                    const MCRegisterInfo *RegInfo) {
69 #ifdef X86_AVAILABLE
70   if (Arch == Triple::x86_64)
71     return createX86MCPlusBuilder(Analysis, Info, RegInfo);
72 #endif
73 
74 #ifdef AARCH64_AVAILABLE
75   if (Arch == Triple::aarch64)
76     return createAArch64MCPlusBuilder(Analysis, Info, RegInfo);
77 #endif
78 
79   llvm_unreachable("architecture unsupported by MCPlusBuilder");
80 }
81 
82 } // anonymous namespace
83 
84 #define DEBUG_TYPE "bolt"
85 
86 Expected<std::unique_ptr<MachORewriteInstance>>
87 MachORewriteInstance::createMachORewriteInstance(
88     object::MachOObjectFile *InputFile, StringRef ToolPath) {
89   Error Err = Error::success();
90   auto MachORI =
91       std::make_unique<MachORewriteInstance>(InputFile, ToolPath, Err);
92   if (Err)
93     return std::move(Err);
94   return std::move(MachORI);
95 }
96 
97 MachORewriteInstance::MachORewriteInstance(object::MachOObjectFile *InputFile,
98                                            StringRef ToolPath, Error &Err)
99     : InputFile(InputFile), ToolPath(ToolPath) {
100   ErrorAsOutParameter EAO(&Err);
101   auto BCOrErr = BinaryContext::createBinaryContext(
102       InputFile, /* IsPIC */ true, DWARFContext::create(*InputFile));
103   if (Error E = BCOrErr.takeError()) {
104     Err = std::move(E);
105     return;
106   }
107   BC = std::move(BCOrErr.get());
108   BC->initializeTarget(std::unique_ptr<MCPlusBuilder>(createMCPlusBuilder(
109       BC->TheTriple->getArch(), BC->MIA.get(), BC->MII.get(), BC->MRI.get())));
110   if (opts::Instrument)
111     BC->setRuntimeLibrary(std::make_unique<InstrumentationRuntimeLibrary>());
112 }
113 
114 Error MachORewriteInstance::setProfile(StringRef Filename) {
115   if (!sys::fs::exists(Filename))
116     return errorCodeToError(make_error_code(errc::no_such_file_or_directory));
117 
118   if (ProfileReader) {
119     // Already exists
120     return make_error<StringError>(
121         Twine("multiple profiles specified: ") + ProfileReader->getFilename() +
122         " and " + Filename, inconvertibleErrorCode());
123   }
124 
125   ProfileReader = std::make_unique<DataReader>(Filename);
126   return Error::success();
127 }
128 
129 void MachORewriteInstance::preprocessProfileData() {
130   if (!ProfileReader)
131     return;
132   if (Error E = ProfileReader->preprocessProfile(*BC.get()))
133     report_error("cannot pre-process profile", std::move(E));
134 }
135 
136 void MachORewriteInstance::processProfileDataPreCFG() {
137   if (!ProfileReader)
138     return;
139   if (Error E = ProfileReader->readProfilePreCFG(*BC.get()))
140     report_error("cannot read profile pre-CFG", std::move(E));
141 }
142 
143 void MachORewriteInstance::processProfileData() {
144   if (!ProfileReader)
145     return;
146   if (Error E = ProfileReader->readProfile(*BC.get()))
147     report_error("cannot read profile", std::move(E));
148 }
149 
150 void MachORewriteInstance::readSpecialSections() {
151   for (const object::SectionRef &Section : InputFile->sections()) {
152     Expected<StringRef> SectionName = Section.getName();;
153     check_error(SectionName.takeError(), "cannot get section name");
154     // Only register sections with names.
155     if (!SectionName->empty()) {
156       BC->registerSection(Section);
157       LLVM_DEBUG(
158           dbgs() << "BOLT-DEBUG: registering section " << *SectionName
159                  << " @ 0x" << Twine::utohexstr(Section.getAddress()) << ":0x"
160                  << Twine::utohexstr(Section.getAddress() + Section.getSize())
161                  << "\n");
162     }
163   }
164 
165   if (opts::PrintSections) {
166     outs() << "BOLT-INFO: Sections from original binary:\n";
167     BC->printSections(outs());
168   }
169 }
170 
171 namespace {
172 
173 struct DataInCodeRegion {
174   explicit DataInCodeRegion(DiceRef D) {
175     D.getOffset(Offset);
176     D.getLength(Length);
177     D.getKind(Kind);
178   }
179 
180   uint32_t Offset;
181   uint16_t Length;
182   uint16_t Kind;
183 };
184 
185 std::vector<DataInCodeRegion> readDataInCode(const MachOObjectFile &O) {
186   const MachO::linkedit_data_command DataInCodeLC =
187       O.getDataInCodeLoadCommand();
188   const uint32_t NumberOfEntries =
189       DataInCodeLC.datasize / sizeof(MachO::data_in_code_entry);
190   std::vector<DataInCodeRegion> DataInCode;
191   DataInCode.reserve(NumberOfEntries);
192   for (auto I = O.begin_dices(), E = O.end_dices(); I != E; ++I)
193     DataInCode.emplace_back(*I);
194   std::stable_sort(DataInCode.begin(), DataInCode.end(),
195                    [](DataInCodeRegion LHS, DataInCodeRegion RHS) {
196                      return LHS.Offset < RHS.Offset;
197                    });
198   return DataInCode;
199 }
200 
201 Optional<uint64_t> readStartAddress(const MachOObjectFile &O) {
202   Optional<uint64_t> StartOffset;
203   Optional<uint64_t> TextVMAddr;
204   for (const object::MachOObjectFile::LoadCommandInfo &LC : O.load_commands()) {
205     switch (LC.C.cmd) {
206     case MachO::LC_MAIN: {
207       MachO::entry_point_command LCMain = O.getEntryPointCommand(LC);
208       StartOffset = LCMain.entryoff;
209       break;
210     }
211     case MachO::LC_SEGMENT: {
212       MachO::segment_command LCSeg = O.getSegmentLoadCommand(LC);
213       StringRef SegmentName(LCSeg.segname,
214                             strnlen(LCSeg.segname, sizeof(LCSeg.segname)));
215       if (SegmentName == "__TEXT")
216         TextVMAddr = LCSeg.vmaddr;
217       break;
218     }
219     case MachO::LC_SEGMENT_64: {
220       MachO::segment_command_64 LCSeg = O.getSegment64LoadCommand(LC);
221       StringRef SegmentName(LCSeg.segname,
222                             strnlen(LCSeg.segname, sizeof(LCSeg.segname)));
223       if (SegmentName == "__TEXT")
224         TextVMAddr = LCSeg.vmaddr;
225       break;
226     }
227     default:
228       continue;
229     }
230   }
231   return (TextVMAddr && StartOffset)
232              ? Optional<uint64_t>(*TextVMAddr + *StartOffset)
233              : llvm::None;
234 }
235 
236 } // anonymous namespace
237 
238 void MachORewriteInstance::discoverFileObjects() {
239   std::vector<SymbolRef> FunctionSymbols;
240   for (const SymbolRef &S : InputFile->symbols()) {
241     SymbolRef::Type Type = cantFail(S.getType(), "cannot get symbol type");
242     if (Type == SymbolRef::ST_Function)
243       FunctionSymbols.push_back(S);
244   }
245   if (FunctionSymbols.empty())
246     return;
247   std::stable_sort(FunctionSymbols.begin(), FunctionSymbols.end(),
248                    [](const SymbolRef &LHS, const SymbolRef &RHS) {
249                      return cantFail(LHS.getValue()) < cantFail(RHS.getValue());
250                    });
251   for (size_t Index = 0; Index < FunctionSymbols.size(); ++Index) {
252     const uint64_t Address = cantFail(FunctionSymbols[Index].getValue());
253     ErrorOr<BinarySection &> Section = BC->getSectionForAddress(Address);
254     // TODO: It happens for some symbols (e.g. __mh_execute_header).
255     // Add proper logic to handle them correctly.
256     if (!Section) {
257       errs() << "BOLT-WARNING: no section found for address " << Address
258              << "\n";
259       continue;
260     }
261 
262     std::string SymbolName =
263         cantFail(FunctionSymbols[Index].getName(), "cannot get symbol name")
264             .str();
265     // Uniquify names of local symbols.
266     if (!(cantFail(FunctionSymbols[Index].getFlags()) & SymbolRef::SF_Global))
267       SymbolName = NR.uniquify(SymbolName);
268 
269     section_iterator S = cantFail(FunctionSymbols[Index].getSection());
270     uint64_t EndAddress = S->getAddress() + S->getSize();
271 
272     size_t NFIndex = Index + 1;
273     // Skip aliases.
274     while (NFIndex < FunctionSymbols.size() &&
275            cantFail(FunctionSymbols[NFIndex].getValue()) == Address)
276       ++NFIndex;
277     if (NFIndex < FunctionSymbols.size() &&
278         S == cantFail(FunctionSymbols[NFIndex].getSection()))
279       EndAddress = cantFail(FunctionSymbols[NFIndex].getValue());
280 
281     const uint64_t SymbolSize = EndAddress - Address;
282     const auto It = BC->getBinaryFunctions().find(Address);
283     if (It == BC->getBinaryFunctions().end()) {
284       BinaryFunction *Function = BC->createBinaryFunction(
285           std::move(SymbolName), *Section, Address, SymbolSize);
286       if (!opts::Instrument)
287         Function->setOutputAddress(Function->getAddress());
288 
289     } else {
290       It->second.addAlternativeName(std::move(SymbolName));
291     }
292   }
293 
294   const std::vector<DataInCodeRegion> DataInCode = readDataInCode(*InputFile);
295 
296   for (auto &BFI : BC->getBinaryFunctions()) {
297     BinaryFunction &Function = BFI.second;
298     Function.setMaxSize(Function.getSize());
299 
300     ErrorOr<ArrayRef<uint8_t>> FunctionData = Function.getData();
301     if (!FunctionData) {
302       errs() << "BOLT-ERROR: corresponding section is non-executable or "
303              << "empty for function " << Function << '\n';
304       continue;
305     }
306 
307     // Treat zero-sized functions as non-simple ones.
308     if (Function.getSize() == 0) {
309       Function.setSimple(false);
310       continue;
311     }
312 
313     // Offset of the function in the file.
314     const auto *FileBegin =
315         reinterpret_cast<const uint8_t *>(InputFile->getData().data());
316     Function.setFileOffset(FunctionData->begin() - FileBegin);
317 
318     // Treat functions which contain data in code as non-simple ones.
319     const auto It = std::lower_bound(
320         DataInCode.cbegin(), DataInCode.cend(), Function.getFileOffset(),
321         [](DataInCodeRegion D, uint64_t Offset) { return D.Offset < Offset; });
322     if (It != DataInCode.cend() &&
323         It->Offset + It->Length <=
324             Function.getFileOffset() + Function.getMaxSize())
325       Function.setSimple(false);
326   }
327 
328   BC->StartFunctionAddress = readStartAddress(*InputFile);
329 }
330 
331 void MachORewriteInstance::disassembleFunctions() {
332   for (auto &BFI : BC->getBinaryFunctions()) {
333     BinaryFunction &Function = BFI.second;
334     if (!Function.isSimple())
335       continue;
336     Function.disassemble();
337     if (opts::PrintDisasm)
338       Function.print(outs(), "after disassembly", true);
339   }
340 }
341 
342 void MachORewriteInstance::buildFunctionsCFG() {
343   for (auto &BFI : BC->getBinaryFunctions()) {
344     BinaryFunction &Function = BFI.second;
345     if (!Function.isSimple())
346       continue;
347     if (!Function.buildCFG(/*AllocId*/ 0)) {
348       errs() << "BOLT-WARNING: failed to build CFG for the function "
349              << Function << "\n";
350     }
351   }
352 }
353 
354 void MachORewriteInstance::postProcessFunctions() {
355   for (auto &BFI : BC->getBinaryFunctions()) {
356     BinaryFunction &Function = BFI.second;
357     if (Function.empty())
358       continue;
359     Function.postProcessCFG();
360     if (opts::PrintCFG)
361       Function.print(outs(), "after building cfg", true);
362   }
363 }
364 
365 void MachORewriteInstance::runOptimizationPasses() {
366   BinaryFunctionPassManager Manager(*BC);
367   if (opts::Instrument) {
368     Manager.registerPass(std::make_unique<PatchEntries>());
369     Manager.registerPass(std::make_unique<Instrumentation>(opts::NeverPrint));
370   }
371 
372   Manager.registerPass(std::make_unique<ShortenInstructions>(opts::NeverPrint));
373 
374   Manager.registerPass(std::make_unique<RemoveNops>(opts::NeverPrint));
375 
376   Manager.registerPass(std::make_unique<NormalizeCFG>(opts::PrintNormalized));
377 
378   Manager.registerPass(
379       std::make_unique<ReorderBasicBlocks>(opts::PrintReordered));
380   Manager.registerPass(
381       std::make_unique<FixupBranches>(opts::PrintAfterBranchFixup));
382   // This pass should always run last.*
383   Manager.registerPass(
384       std::make_unique<FinalizeFunctions>(opts::PrintFinalized));
385 
386   Manager.runPasses();
387 }
388 
389 void MachORewriteInstance::mapInstrumentationSection(StringRef SectionName) {
390   if (!opts::Instrument)
391     return;
392   ErrorOr<BinarySection &> Section = BC->getUniqueSectionByName(SectionName);
393   if (!Section) {
394     llvm::errs() << "Cannot find " + SectionName + " section\n";
395     exit(1);
396   }
397   if (!Section->hasValidSectionID())
398     return;
399   RTDyld->reassignSectionAddress(Section->getSectionID(),
400                                  Section->getAddress());
401 }
402 
403 void MachORewriteInstance::mapCodeSections() {
404   for (BinaryFunction *Function : BC->getAllBinaryFunctions()) {
405     if (!Function->isEmitted())
406       continue;
407     if (Function->getOutputAddress() == 0)
408       continue;
409     ErrorOr<BinarySection &> FuncSection = Function->getCodeSection();
410     if (!FuncSection)
411       report_error(
412           (Twine("Cannot find section for function ") + Function->getOneName())
413               .str(),
414           FuncSection.getError());
415 
416     FuncSection->setOutputAddress(Function->getOutputAddress());
417     LLVM_DEBUG(dbgs() << "BOLT: mapping 0x"
418                  << Twine::utohexstr(FuncSection->getAllocAddress()) << " to 0x"
419                  << Twine::utohexstr(Function->getOutputAddress()) << '\n');
420     RTDyld->reassignSectionAddress(FuncSection->getSectionID(),
421                                    Function->getOutputAddress());
422     Function->setImageAddress(FuncSection->getAllocAddress());
423     Function->setImageSize(FuncSection->getOutputSize());
424   }
425 
426   if (opts::Instrument) {
427     ErrorOr<BinarySection &> BOLT = BC->getUniqueSectionByName("__bolt");
428     if (!BOLT) {
429       llvm::errs() << "Cannot find __bolt section\n";
430       exit(1);
431     }
432     uint64_t Addr = BOLT->getAddress();
433     for (BinaryFunction *Function : BC->getAllBinaryFunctions()) {
434       if (!Function->isEmitted())
435         continue;
436       if (Function->getOutputAddress() != 0)
437         continue;
438       ErrorOr<BinarySection &> FuncSection = Function->getCodeSection();
439       assert(FuncSection && "cannot find section for function");
440       Addr = llvm::alignTo(Addr, 4);
441       FuncSection->setOutputAddress(Addr);
442       RTDyld->reassignSectionAddress(FuncSection->getSectionID(), Addr);
443       Function->setFileOffset(Addr - BOLT->getAddress() +
444                               BOLT->getInputFileOffset());
445       Function->setImageAddress(FuncSection->getAllocAddress());
446       Function->setImageSize(FuncSection->getOutputSize());
447       BC->registerNameAtAddress(Function->getOneName(), Addr, 0, 0);
448       Addr += FuncSection->getOutputSize();
449     }
450   }
451 }
452 
453 namespace {
454 
455 class BOLTSymbolResolver : public LegacyJITSymbolResolver {
456   BinaryContext &BC;
457 public:
458   BOLTSymbolResolver(BinaryContext &BC) : BC(BC) {}
459 
460   JITSymbol findSymbolInLogicalDylib(const std::string &Name) override {
461     return JITSymbol(nullptr);
462   }
463 
464   JITSymbol findSymbol(const std::string &Name) override {
465     LLVM_DEBUG(dbgs() << "BOLT: looking for " << Name << "\n");
466     if (BinaryData *I = BC.getBinaryDataByName(Name)) {
467       const uint64_t Address = I->isMoved() && !I->isJumpTable()
468                                    ? I->getOutputAddress()
469                                    : I->getAddress();
470       LLVM_DEBUG(dbgs() << "Resolved to address 0x" << Twine::utohexstr(Address)
471                         << "\n");
472       return JITSymbol(Address, JITSymbolFlags());
473     }
474     LLVM_DEBUG(dbgs() << "Resolved to address 0x0\n");
475     return JITSymbol(nullptr);
476   }
477 };
478 
479 } // end anonymous namespace
480 
481 void MachORewriteInstance::emitAndLink() {
482   std::error_code EC;
483   std::unique_ptr<::llvm::ToolOutputFile> TempOut =
484       std::make_unique<::llvm::ToolOutputFile>(
485           opts::OutputFilename + ".bolt.o", EC, sys::fs::OF_None);
486   check_error(EC, "cannot create output object file");
487 
488   if (opts::KeepTmp)
489     TempOut->keep();
490 
491   std::unique_ptr<buffer_ostream> BOS =
492       std::make_unique<buffer_ostream>(TempOut->os());
493   raw_pwrite_stream *OS = BOS.get();
494   auto Streamer = BC->createStreamer(*OS);
495 
496   emitBinaryContext(*Streamer, *BC, getOrgSecPrefix());
497   Streamer->finish();
498 
499   std::unique_ptr<MemoryBuffer> ObjectMemBuffer =
500       MemoryBuffer::getMemBuffer(BOS->str(), "in-memory object file", false);
501   std::unique_ptr<object::ObjectFile> Obj = cantFail(
502       object::ObjectFile::createObjectFile(ObjectMemBuffer->getMemBufferRef()),
503       "error creating in-memory object");
504   assert(Obj && "createObjectFile cannot return nullptr");
505 
506   BOLTSymbolResolver Resolver = BOLTSymbolResolver(*BC);
507 
508   MCAsmLayout FinalLayout(
509       static_cast<MCObjectStreamer *>(Streamer.get())->getAssembler());
510 
511   BC->EFMM.reset(new ExecutableFileMemoryManager(*BC, /*AllowStubs*/ false));
512 
513   RTDyld.reset(new decltype(RTDyld)::element_type(*BC->EFMM, Resolver));
514   RTDyld->setProcessAllSections(true);
515   RTDyld->loadObject(*Obj);
516   if (RTDyld->hasError()) {
517     outs() << "BOLT-ERROR: RTDyld failed.\n";
518     exit(1);
519   }
520 
521   // Assign addresses to all sections. If key corresponds to the object
522   // created by ourselves, call our regular mapping function. If we are
523   // loading additional objects as part of runtime libraries for
524   // instrumentation, treat them as extra sections.
525   mapCodeSections();
526   mapInstrumentationSection("__counters");
527   mapInstrumentationSection("__tables");
528 
529           // TODO: Refactor addRuntimeLibSections to work properly on Mach-O
530           // and use it here.
531   //FIXME! Put this in RtLibrary->link
532 //          mapInstrumentationSection("I__setup");
533 //          mapInstrumentationSection("I__fini");
534 //          mapInstrumentationSection("I__data");
535 //          mapInstrumentationSection("I__text");
536 //          mapInstrumentationSection("I__cstring");
537 //          mapInstrumentationSection("I__literal16");
538 
539 //  if (auto *RtLibrary = BC->getRuntimeLibrary()) {
540 //    RtLibrary->link(*BC, ToolPath, *ES, *OLT);
541 //  }
542 }
543 
544 void MachORewriteInstance::writeInstrumentationSection(StringRef SectionName,
545                                                        raw_pwrite_stream &OS) {
546   if (!opts::Instrument)
547     return;
548   ErrorOr<BinarySection &> Section = BC->getUniqueSectionByName(SectionName);
549   if (!Section) {
550     llvm::errs() << "Cannot find " + SectionName + " section\n";
551     exit(1);
552   }
553   if (!Section->hasValidSectionID())
554     return;
555   assert(Section->getInputFileOffset() &&
556          "Section input offset cannot be zero");
557   assert(Section->getAllocAddress() && "Section alloc address cannot be zero");
558   assert(Section->getOutputSize() && "Section output size cannot be zero");
559   OS.pwrite(reinterpret_cast<char *>(Section->getAllocAddress()),
560             Section->getOutputSize(), Section->getInputFileOffset());
561 }
562 
563 void MachORewriteInstance::rewriteFile() {
564   std::error_code EC;
565   Out = std::make_unique<ToolOutputFile>(opts::OutputFilename, EC,
566                                          sys::fs::OF_None);
567   check_error(EC, "cannot create output executable file");
568   raw_fd_ostream &OS = Out->os();
569   OS << InputFile->getData();
570 
571   for (auto &BFI : BC->getBinaryFunctions()) {
572     BinaryFunction &Function = BFI.second;
573     if (!Function.isSimple())
574       continue;
575     assert(Function.isEmitted() && "Simple function has not been emitted");
576     if (!opts::Instrument && (Function.getImageSize() > Function.getMaxSize()))
577       continue;
578     if (opts::Verbosity >= 2)
579       outs() << "BOLT: rewriting function \"" << Function << "\"\n";
580     OS.pwrite(reinterpret_cast<char *>(Function.getImageAddress()),
581               Function.getImageSize(), Function.getFileOffset());
582   }
583 
584   for (const BinaryFunction *Function : BC->getInjectedBinaryFunctions()) {
585     OS.pwrite(reinterpret_cast<char *>(Function->getImageAddress()),
586               Function->getImageSize(), Function->getFileOffset());
587   }
588 
589   writeInstrumentationSection("__counters", OS);
590   writeInstrumentationSection("__tables", OS);
591 
592   // TODO: Refactor addRuntimeLibSections to work properly on Mach-O and
593   // use it here.
594   writeInstrumentationSection("I__setup", OS);
595   writeInstrumentationSection("I__fini", OS);
596   writeInstrumentationSection("I__data", OS);
597   writeInstrumentationSection("I__text", OS);
598   writeInstrumentationSection("I__cstring", OS);
599   writeInstrumentationSection("I__literal16", OS);
600 
601   Out->keep();
602   EC = sys::fs::setPermissions(opts::OutputFilename,
603                                sys::fs::perms::all_all);
604   check_error(EC, "cannot set permissions of output file");
605 }
606 
607 void MachORewriteInstance::adjustCommandLineOptions() {
608 //FIXME! Upstream change
609 //  opts::CheckOverlappingElements = false;
610   if (!opts::AlignText.getNumOccurrences())
611     opts::AlignText = BC->PageAlign;
612   if (opts::Instrument.getNumOccurrences())
613     opts::ForcePatch = true;
614   opts::JumpTables = JTS_MOVE;
615   opts::InstrumentCalls = false;
616   opts::RuntimeInstrumentationLib = "libbolt_rt_instr_osx.a";
617 }
618 
619 void MachORewriteInstance::run() {
620   adjustCommandLineOptions();
621 
622   readSpecialSections();
623 
624   discoverFileObjects();
625 
626   preprocessProfileData();
627 
628   disassembleFunctions();
629 
630   processProfileDataPreCFG();
631 
632   buildFunctionsCFG();
633 
634   processProfileData();
635 
636   postProcessFunctions();
637 
638   runOptimizationPasses();
639 
640   emitAndLink();
641 
642   rewriteFile();
643 }
644 
645 MachORewriteInstance::~MachORewriteInstance() {}
646 
647 } // namespace bolt
648 } // namespace llvm
649