LLVM  7.0.0svn
LTO.cpp
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1 //===-LTO.cpp - LLVM Link Time Optimizer ----------------------------------===//
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 // This file implements functions and classes used to support LTO.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/LTO/LTO.h"
15 #include "llvm/ADT/Statistic.h"
20 #include "llvm/CodeGen/Analysis.h"
21 #include "llvm/Config/llvm-config.h"
22 #include "llvm/IR/AutoUpgrade.h"
25 #include "llvm/IR/Mangler.h"
26 #include "llvm/IR/Metadata.h"
27 #include "llvm/LTO/LTOBackend.h"
28 #include "llvm/Linker/IRMover.h"
30 #include "llvm/Support/Error.h"
33 #include "llvm/Support/Path.h"
34 #include "llvm/Support/SHA1.h"
35 #include "llvm/Support/SourceMgr.h"
38 #include "llvm/Support/Threading.h"
39 #include "llvm/Support/VCSRevision.h"
43 #include "llvm/Transforms/IPO.h"
46 
47 #include <set>
48 
49 using namespace llvm;
50 using namespace lto;
51 using namespace object;
52 
53 #define DEBUG_TYPE "lto"
54 
55 static cl::opt<bool>
56  DumpThinCGSCCs("dump-thin-cg-sccs", cl::init(false), cl::Hidden,
57  cl::desc("Dump the SCCs in the ThinLTO index's callgraph"));
58 
59 // The values are (type identifier, summary) pairs.
60 typedef DenseMap<
64 
65 // Returns a unique hash for the Module considering the current list of
66 // export/import and other global analysis results.
67 // The hash is produced in \p Key.
68 static void computeCacheKey(
69  SmallString<40> &Key, const Config &Conf, const ModuleSummaryIndex &Index,
70  StringRef ModuleID, const FunctionImporter::ImportMapTy &ImportList,
71  const FunctionImporter::ExportSetTy &ExportList,
72  const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
73  const GVSummaryMapTy &DefinedGlobals,
74  const TypeIdSummariesByGuidTy &TypeIdSummariesByGuid,
75  const std::set<GlobalValue::GUID> &CfiFunctionDefs,
76  const std::set<GlobalValue::GUID> &CfiFunctionDecls) {
77  // Compute the unique hash for this entry.
78  // This is based on the current compiler version, the module itself, the
79  // export list, the hash for every single module in the import list, the
80  // list of ResolvedODR for the module, and the list of preserved symbols.
81  SHA1 Hasher;
82 
83  // Start with the compiler revision
84  Hasher.update(LLVM_VERSION_STRING);
85 #ifdef LLVM_REVISION
86  Hasher.update(LLVM_REVISION);
87 #endif
88 
89  // Include the parts of the LTO configuration that affect code generation.
90  auto AddString = [&](StringRef Str) {
91  Hasher.update(Str);
92  Hasher.update(ArrayRef<uint8_t>{0});
93  };
94  auto AddUnsigned = [&](unsigned I) {
95  uint8_t Data[4];
96  Data[0] = I;
97  Data[1] = I >> 8;
98  Data[2] = I >> 16;
99  Data[3] = I >> 24;
100  Hasher.update(ArrayRef<uint8_t>{Data, 4});
101  };
102  auto AddUint64 = [&](uint64_t I) {
103  uint8_t Data[8];
104  Data[0] = I;
105  Data[1] = I >> 8;
106  Data[2] = I >> 16;
107  Data[3] = I >> 24;
108  Data[4] = I >> 32;
109  Data[5] = I >> 40;
110  Data[6] = I >> 48;
111  Data[7] = I >> 56;
112  Hasher.update(ArrayRef<uint8_t>{Data, 8});
113  };
114  AddString(Conf.CPU);
115  // FIXME: Hash more of Options. For now all clients initialize Options from
116  // command-line flags (which is unsupported in production), but may set
117  // RelaxELFRelocations. The clang driver can also pass FunctionSections,
118  // DataSections and DebuggerTuning via command line flags.
119  AddUnsigned(Conf.Options.RelaxELFRelocations);
120  AddUnsigned(Conf.Options.FunctionSections);
121  AddUnsigned(Conf.Options.DataSections);
122  AddUnsigned((unsigned)Conf.Options.DebuggerTuning);
123  for (auto &A : Conf.MAttrs)
124  AddString(A);
125  if (Conf.RelocModel)
126  AddUnsigned(*Conf.RelocModel);
127  else
128  AddUnsigned(-1);
129  if (Conf.CodeModel)
130  AddUnsigned(*Conf.CodeModel);
131  else
132  AddUnsigned(-1);
133  AddUnsigned(Conf.CGOptLevel);
134  AddUnsigned(Conf.CGFileType);
135  AddUnsigned(Conf.OptLevel);
136  AddUnsigned(Conf.UseNewPM);
137  AddString(Conf.OptPipeline);
138  AddString(Conf.AAPipeline);
139  AddString(Conf.OverrideTriple);
140  AddString(Conf.DefaultTriple);
141  AddString(Conf.DwoDir);
142 
143  // Include the hash for the current module
144  auto ModHash = Index.getModuleHash(ModuleID);
145  Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash)));
146  for (auto F : ExportList)
147  // The export list can impact the internalization, be conservative here
148  Hasher.update(ArrayRef<uint8_t>((uint8_t *)&F, sizeof(F)));
149 
150  // Include the hash for every module we import functions from. The set of
151  // imported symbols for each module may affect code generation and is
152  // sensitive to link order, so include that as well.
153  for (auto &Entry : ImportList) {
154  auto ModHash = Index.getModuleHash(Entry.first());
155  Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash)));
156 
157  AddUint64(Entry.second.size());
158  for (auto &Fn : Entry.second)
159  AddUint64(Fn);
160  }
161 
162  // Include the hash for the resolved ODR.
163  for (auto &Entry : ResolvedODR) {
164  Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.first,
165  sizeof(GlobalValue::GUID)));
166  Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.second,
167  sizeof(GlobalValue::LinkageTypes)));
168  }
169 
170  // Members of CfiFunctionDefs and CfiFunctionDecls that are referenced or
171  // defined in this module.
172  std::set<GlobalValue::GUID> UsedCfiDefs;
173  std::set<GlobalValue::GUID> UsedCfiDecls;
174 
175  // Typeids used in this module.
176  std::set<GlobalValue::GUID> UsedTypeIds;
177 
178  auto AddUsedCfiGlobal = [&](GlobalValue::GUID ValueGUID) {
179  if (CfiFunctionDefs.count(ValueGUID))
180  UsedCfiDefs.insert(ValueGUID);
181  if (CfiFunctionDecls.count(ValueGUID))
182  UsedCfiDecls.insert(ValueGUID);
183  };
184 
185  auto AddUsedThings = [&](GlobalValueSummary *GS) {
186  if (!GS) return;
187  AddUnsigned(GS->isLive());
188  for (const ValueInfo &VI : GS->refs()) {
189  AddUnsigned(VI.isDSOLocal());
190  AddUsedCfiGlobal(VI.getGUID());
191  }
192  if (auto *FS = dyn_cast<FunctionSummary>(GS)) {
193  for (auto &TT : FS->type_tests())
194  UsedTypeIds.insert(TT);
195  for (auto &TT : FS->type_test_assume_vcalls())
196  UsedTypeIds.insert(TT.GUID);
197  for (auto &TT : FS->type_checked_load_vcalls())
198  UsedTypeIds.insert(TT.GUID);
199  for (auto &TT : FS->type_test_assume_const_vcalls())
200  UsedTypeIds.insert(TT.VFunc.GUID);
201  for (auto &TT : FS->type_checked_load_const_vcalls())
202  UsedTypeIds.insert(TT.VFunc.GUID);
203  for (auto &ET : FS->calls()) {
204  AddUnsigned(ET.first.isDSOLocal());
205  AddUsedCfiGlobal(ET.first.getGUID());
206  }
207  }
208  };
209 
210  // Include the hash for the linkage type to reflect internalization and weak
211  // resolution, and collect any used type identifier resolutions.
212  for (auto &GS : DefinedGlobals) {
213  GlobalValue::LinkageTypes Linkage = GS.second->linkage();
214  Hasher.update(
215  ArrayRef<uint8_t>((const uint8_t *)&Linkage, sizeof(Linkage)));
216  AddUsedCfiGlobal(GS.first);
217  AddUsedThings(GS.second);
218  }
219 
220  // Imported functions may introduce new uses of type identifier resolutions,
221  // so we need to collect their used resolutions as well.
222  for (auto &ImpM : ImportList)
223  for (auto &ImpF : ImpM.second)
224  AddUsedThings(Index.findSummaryInModule(ImpF, ImpM.first()));
225 
226  auto AddTypeIdSummary = [&](StringRef TId, const TypeIdSummary &S) {
227  AddString(TId);
228 
229  AddUnsigned(S.TTRes.TheKind);
230  AddUnsigned(S.TTRes.SizeM1BitWidth);
231 
232  AddUint64(S.TTRes.AlignLog2);
233  AddUint64(S.TTRes.SizeM1);
234  AddUint64(S.TTRes.BitMask);
235  AddUint64(S.TTRes.InlineBits);
236 
237  AddUint64(S.WPDRes.size());
238  for (auto &WPD : S.WPDRes) {
239  AddUnsigned(WPD.first);
240  AddUnsigned(WPD.second.TheKind);
241  AddString(WPD.second.SingleImplName);
242 
243  AddUint64(WPD.second.ResByArg.size());
244  for (auto &ByArg : WPD.second.ResByArg) {
245  AddUint64(ByArg.first.size());
246  for (uint64_t Arg : ByArg.first)
247  AddUint64(Arg);
248  AddUnsigned(ByArg.second.TheKind);
249  AddUint64(ByArg.second.Info);
250  AddUnsigned(ByArg.second.Byte);
251  AddUnsigned(ByArg.second.Bit);
252  }
253  }
254  };
255 
256  // Include the hash for all type identifiers used by this module.
257  for (GlobalValue::GUID TId : UsedTypeIds) {
258  auto SummariesI = TypeIdSummariesByGuid.find(TId);
259  if (SummariesI != TypeIdSummariesByGuid.end())
260  for (auto *Summary : SummariesI->second)
261  AddTypeIdSummary(Summary->first, Summary->second);
262  }
263 
264  AddUnsigned(UsedCfiDefs.size());
265  for (auto &V : UsedCfiDefs)
266  AddUint64(V);
267 
268  AddUnsigned(UsedCfiDecls.size());
269  for (auto &V : UsedCfiDecls)
270  AddUint64(V);
271 
272  if (!Conf.SampleProfile.empty()) {
273  auto FileOrErr = MemoryBuffer::getFile(Conf.SampleProfile);
274  if (FileOrErr)
275  Hasher.update(FileOrErr.get()->getBuffer());
276  }
277 
278  Key = toHex(Hasher.result());
279 }
280 
282  GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID,
283  DenseSet<GlobalValueSummary *> &GlobalInvolvedWithAlias,
284  function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
285  isPrevailing,
286  function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)>
287  recordNewLinkage) {
288  for (auto &S : GVSummaryList) {
289  GlobalValue::LinkageTypes OriginalLinkage = S->linkage();
290  if (!GlobalValue::isWeakForLinker(OriginalLinkage))
291  continue;
292  // We need to emit only one of these. The prevailing module will keep it,
293  // but turned into a weak, while the others will drop it when possible.
294  // This is both a compile-time optimization and a correctness
295  // transformation. This is necessary for correctness when we have exported
296  // a reference - we need to convert the linkonce to weak to
297  // ensure a copy is kept to satisfy the exported reference.
298  // FIXME: We may want to split the compile time and correctness
299  // aspects into separate routines.
300  if (isPrevailing(GUID, S.get())) {
301  if (GlobalValue::isLinkOnceLinkage(OriginalLinkage))
302  S->setLinkage(GlobalValue::getWeakLinkage(
303  GlobalValue::isLinkOnceODRLinkage(OriginalLinkage)));
304  }
305  // Alias and aliasee can't be turned into available_externally.
306  else if (!isa<AliasSummary>(S.get()) &&
307  !GlobalInvolvedWithAlias.count(S.get()))
309  if (S->linkage() != OriginalLinkage)
310  recordNewLinkage(S->modulePath(), GUID, S->linkage());
311  }
312 }
313 
314 // Resolve Weak and LinkOnce values in the \p Index.
315 //
316 // We'd like to drop these functions if they are no longer referenced in the
317 // current module. However there is a chance that another module is still
318 // referencing them because of the import. We make sure we always emit at least
319 // one copy.
322  function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
323  isPrevailing,
324  function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)>
325  recordNewLinkage) {
326  // We won't optimize the globals that are referenced by an alias for now
327  // Ideally we should turn the alias into a global and duplicate the definition
328  // when needed.
329  DenseSet<GlobalValueSummary *> GlobalInvolvedWithAlias;
330  for (auto &I : Index)
331  for (auto &S : I.second.SummaryList)
332  if (auto AS = dyn_cast<AliasSummary>(S.get()))
333  GlobalInvolvedWithAlias.insert(&AS->getAliasee());
334 
335  for (auto &I : Index)
336  thinLTOResolveWeakForLinkerGUID(I.second.SummaryList, I.first,
337  GlobalInvolvedWithAlias, isPrevailing,
338  recordNewLinkage);
339 }
340 
342  GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID,
343  function_ref<bool(StringRef, GlobalValue::GUID)> isExported) {
344  for (auto &S : GVSummaryList) {
345  if (isExported(S->modulePath(), GUID)) {
346  if (GlobalValue::isLocalLinkage(S->linkage()))
347  S->setLinkage(GlobalValue::ExternalLinkage);
348  } else if (!GlobalValue::isLocalLinkage(S->linkage()))
349  S->setLinkage(GlobalValue::InternalLinkage);
350  }
351 }
352 
353 // Update the linkages in the given \p Index to mark exported values
354 // as external and non-exported values as internal.
356  ModuleSummaryIndex &Index,
357  function_ref<bool(StringRef, GlobalValue::GUID)> isExported) {
358  for (auto &I : Index)
359  thinLTOInternalizeAndPromoteGUID(I.second.SummaryList, I.first, isExported);
360 }
361 
362 // Requires a destructor for std::vector<InputModule>.
363 InputFile::~InputFile() = default;
364 
366  std::unique_ptr<InputFile> File(new InputFile);
367 
368  Expected<IRSymtabFile> FOrErr = readIRSymtab(Object);
369  if (!FOrErr)
370  return FOrErr.takeError();
371 
372  File->TargetTriple = FOrErr->TheReader.getTargetTriple();
373  File->SourceFileName = FOrErr->TheReader.getSourceFileName();
374  File->COFFLinkerOpts = FOrErr->TheReader.getCOFFLinkerOpts();
375  File->ComdatTable = FOrErr->TheReader.getComdatTable();
376 
377  for (unsigned I = 0; I != FOrErr->Mods.size(); ++I) {
378  size_t Begin = File->Symbols.size();
379  for (const irsymtab::Reader::SymbolRef &Sym :
380  FOrErr->TheReader.module_symbols(I))
381  // Skip symbols that are irrelevant to LTO. Note that this condition needs
382  // to match the one in Skip() in LTO::addRegularLTO().
383  if (Sym.isGlobal() && !Sym.isFormatSpecific())
384  File->Symbols.push_back(Sym);
385  File->ModuleSymIndices.push_back({Begin, File->Symbols.size()});
386  }
387 
388  File->Mods = FOrErr->Mods;
389  File->Strtab = std::move(FOrErr->Strtab);
390  return std::move(File);
391 }
392 
394  return Mods[0].getModuleIdentifier();
395 }
396 
397 LTO::RegularLTOState::RegularLTOState(unsigned ParallelCodeGenParallelismLevel,
398  Config &Conf)
399  : ParallelCodeGenParallelismLevel(ParallelCodeGenParallelismLevel),
400  Ctx(Conf), CombinedModule(llvm::make_unique<Module>("ld-temp.o", Ctx)),
401  Mover(llvm::make_unique<IRMover>(*CombinedModule)) {}
402 
403 LTO::ThinLTOState::ThinLTOState(ThinBackend Backend)
404  : Backend(Backend), CombinedIndex(/*HaveGVs*/ false) {
405  if (!Backend)
406  this->Backend =
408 }
409 
411  unsigned ParallelCodeGenParallelismLevel)
412  : Conf(std::move(Conf)),
413  RegularLTO(ParallelCodeGenParallelismLevel, this->Conf),
414  ThinLTO(std::move(Backend)) {}
415 
416 // Requires a destructor for MapVector<BitcodeModule>.
417 LTO::~LTO() = default;
418 
419 // Add the symbols in the given module to the GlobalResolutions map, and resolve
420 // their partitions.
421 void LTO::addModuleToGlobalRes(ArrayRef<InputFile::Symbol> Syms,
423  unsigned Partition, bool InSummary) {
424  auto *ResI = Res.begin();
425  auto *ResE = Res.end();
426  (void)ResE;
427  for (const InputFile::Symbol &Sym : Syms) {
428  assert(ResI != ResE);
429  SymbolResolution Res = *ResI++;
430 
431  auto &GlobalRes = GlobalResolutions[Sym.getName()];
432  GlobalRes.UnnamedAddr &= Sym.isUnnamedAddr();
433  if (Res.Prevailing) {
434  assert(!GlobalRes.Prevailing &&
435  "Multiple prevailing defs are not allowed");
436  GlobalRes.Prevailing = true;
437  GlobalRes.IRName = Sym.getIRName();
438  } else if (!GlobalRes.Prevailing && GlobalRes.IRName.empty()) {
439  // Sometimes it can be two copies of symbol in a module and prevailing
440  // symbol can have no IR name. That might happen if symbol is defined in
441  // module level inline asm block. In case we have multiple modules with
442  // the same symbol we want to use IR name of the prevailing symbol.
443  // Otherwise, if we haven't seen a prevailing symbol, set the name so that
444  // we can later use it to check if there is any prevailing copy in IR.
445  GlobalRes.IRName = Sym.getIRName();
446  }
447 
448  // Set the partition to external if we know it is re-defined by the linker
449  // with -defsym or -wrap options, used elsewhere, e.g. it is visible to a
450  // regular object, is referenced from llvm.compiler_used, or was already
451  // recorded as being referenced from a different partition.
452  if (Res.LinkerRedefined || Res.VisibleToRegularObj || Sym.isUsed() ||
453  (GlobalRes.Partition != GlobalResolution::Unknown &&
454  GlobalRes.Partition != Partition)) {
455  GlobalRes.Partition = GlobalResolution::External;
456  } else
457  // First recorded reference, save the current partition.
458  GlobalRes.Partition = Partition;
459 
460  // Flag as visible outside of summary if visible from a regular object or
461  // from a module that does not have a summary.
462  GlobalRes.VisibleOutsideSummary |=
463  (Res.VisibleToRegularObj || Sym.isUsed() || !InSummary);
464  }
465 }
466 
469  StringRef Path = Input->getName();
470  OS << Path << '\n';
471  auto ResI = Res.begin();
472  for (const InputFile::Symbol &Sym : Input->symbols()) {
473  assert(ResI != Res.end());
474  SymbolResolution Res = *ResI++;
475 
476  OS << "-r=" << Path << ',' << Sym.getName() << ',';
477  if (Res.Prevailing)
478  OS << 'p';
479  if (Res.FinalDefinitionInLinkageUnit)
480  OS << 'l';
481  if (Res.VisibleToRegularObj)
482  OS << 'x';
483  if (Res.LinkerRedefined)
484  OS << 'r';
485  OS << '\n';
486  }
487  OS.flush();
488  assert(ResI == Res.end());
489 }
490 
491 Error LTO::add(std::unique_ptr<InputFile> Input,
493  assert(!CalledGetMaxTasks);
494 
495  if (Conf.ResolutionFile)
496  writeToResolutionFile(*Conf.ResolutionFile, Input.get(), Res);
497 
498  if (RegularLTO.CombinedModule->getTargetTriple().empty())
499  RegularLTO.CombinedModule->setTargetTriple(Input->getTargetTriple());
500 
501  const SymbolResolution *ResI = Res.begin();
502  for (unsigned I = 0; I != Input->Mods.size(); ++I)
503  if (Error Err = addModule(*Input, I, ResI, Res.end()))
504  return Err;
505 
506  assert(ResI == Res.end());
507  return Error::success();
508 }
509 
510 Error LTO::addModule(InputFile &Input, unsigned ModI,
511  const SymbolResolution *&ResI,
512  const SymbolResolution *ResE) {
513  Expected<BitcodeLTOInfo> LTOInfo = Input.Mods[ModI].getLTOInfo();
514  if (!LTOInfo)
515  return LTOInfo.takeError();
516 
517  BitcodeModule BM = Input.Mods[ModI];
518  auto ModSyms = Input.module_symbols(ModI);
519  addModuleToGlobalRes(ModSyms, {ResI, ResE},
520  LTOInfo->IsThinLTO ? ThinLTO.ModuleMap.size() + 1 : 0,
521  LTOInfo->HasSummary);
522 
523  if (LTOInfo->IsThinLTO)
524  return addThinLTO(BM, ModSyms, ResI, ResE);
525 
527  addRegularLTO(BM, ModSyms, ResI, ResE);
528  if (!ModOrErr)
529  return ModOrErr.takeError();
530 
531  if (!LTOInfo->HasSummary)
532  return linkRegularLTO(std::move(*ModOrErr), /*LivenessFromIndex=*/false);
533 
534  // Regular LTO module summaries are added to a dummy module that represents
535  // the combined regular LTO module.
536  if (Error Err = BM.readSummary(ThinLTO.CombinedIndex, "", -1ull))
537  return Err;
538  RegularLTO.ModsWithSummaries.push_back(std::move(*ModOrErr));
539  return Error::success();
540 }
541 
542 // Checks whether the given global value is in a non-prevailing comdat
543 // (comdat containing values the linker indicated were not prevailing,
544 // which we then dropped to available_externally), and if so, removes
545 // it from the comdat. This is called for all global values to ensure the
546 // comdat is empty rather than leaving an incomplete comdat. It is needed for
547 // regular LTO modules, in case we are in a mixed-LTO mode (both regular
548 // and thin LTO modules) compilation. Since the regular LTO module will be
549 // linked first in the final native link, we want to make sure the linker
550 // doesn't select any of these incomplete comdats that would be left
551 // in the regular LTO module without this cleanup.
552 static void
554  std::set<const Comdat *> &NonPrevailingComdats) {
555  Comdat *C = GV.getComdat();
556  if (!C)
557  return;
558 
559  if (!NonPrevailingComdats.count(C))
560  return;
561 
562  // Additionally need to drop externally visible global values from the comdat
563  // to available_externally, so that there aren't multiply defined linker
564  // errors.
565  if (!GV.hasLocalLinkage())
567 
568  if (auto GO = dyn_cast<GlobalObject>(&GV))
569  GO->setComdat(nullptr);
570 }
571 
572 // Add a regular LTO object to the link.
573 // The resulting module needs to be linked into the combined LTO module with
574 // linkRegularLTO.
576 LTO::addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
577  const SymbolResolution *&ResI,
578  const SymbolResolution *ResE) {
579  RegularLTOState::AddedModule Mod;
581  BM.getLazyModule(RegularLTO.Ctx, /*ShouldLazyLoadMetadata*/ true,
582  /*IsImporting*/ false);
583  if (!MOrErr)
584  return MOrErr.takeError();
585  Module &M = **MOrErr;
586  Mod.M = std::move(*MOrErr);
587 
588  if (Error Err = M.materializeMetadata())
589  return std::move(Err);
590  UpgradeDebugInfo(M);
591 
592  ModuleSymbolTable SymTab;
593  SymTab.addModule(&M);
594 
595  for (GlobalVariable &GV : M.globals())
596  if (GV.hasAppendingLinkage())
597  Mod.Keep.push_back(&GV);
598 
599  DenseSet<GlobalObject *> AliasedGlobals;
600  for (auto &GA : M.aliases())
601  if (GlobalObject *GO = GA.getBaseObject())
602  AliasedGlobals.insert(GO);
603 
604  // In this function we need IR GlobalValues matching the symbols in Syms
605  // (which is not backed by a module), so we need to enumerate them in the same
606  // order. The symbol enumeration order of a ModuleSymbolTable intentionally
607  // matches the order of an irsymtab, but when we read the irsymtab in
608  // InputFile::create we omit some symbols that are irrelevant to LTO. The
609  // Skip() function skips the same symbols from the module as InputFile does
610  // from the symbol table.
611  auto MsymI = SymTab.symbols().begin(), MsymE = SymTab.symbols().end();
612  auto Skip = [&]() {
613  while (MsymI != MsymE) {
614  auto Flags = SymTab.getSymbolFlags(*MsymI);
615  if ((Flags & object::BasicSymbolRef::SF_Global) &&
617  return;
618  ++MsymI;
619  }
620  };
621  Skip();
622 
623  std::set<const Comdat *> NonPrevailingComdats;
624  for (const InputFile::Symbol &Sym : Syms) {
625  assert(ResI != ResE);
626  SymbolResolution Res = *ResI++;
627 
628  assert(MsymI != MsymE);
629  ModuleSymbolTable::Symbol Msym = *MsymI++;
630  Skip();
631 
632  if (GlobalValue *GV = Msym.dyn_cast<GlobalValue *>()) {
633  if (Res.Prevailing) {
634  if (Sym.isUndefined())
635  continue;
636  Mod.Keep.push_back(GV);
637  // For symbols re-defined with linker -wrap and -defsym options,
638  // set the linkage to weak to inhibit IPO. The linkage will be
639  // restored by the linker.
640  if (Res.LinkerRedefined)
641  GV->setLinkage(GlobalValue::WeakAnyLinkage);
642 
643  GlobalValue::LinkageTypes OriginalLinkage = GV->getLinkage();
644  if (GlobalValue::isLinkOnceLinkage(OriginalLinkage))
645  GV->setLinkage(GlobalValue::getWeakLinkage(
646  GlobalValue::isLinkOnceODRLinkage(OriginalLinkage)));
647  } else if (isa<GlobalObject>(GV) &&
648  (GV->hasLinkOnceODRLinkage() || GV->hasWeakODRLinkage() ||
649  GV->hasAvailableExternallyLinkage()) &&
650  !AliasedGlobals.count(cast<GlobalObject>(GV))) {
651  // Any of the above three types of linkage indicates that the
652  // chosen prevailing symbol will have the same semantics as this copy of
653  // the symbol, so we may be able to link it with available_externally
654  // linkage. We will decide later whether to do that when we link this
655  // module (in linkRegularLTO), based on whether it is undefined.
656  Mod.Keep.push_back(GV);
658  if (GV->hasComdat())
659  NonPrevailingComdats.insert(GV->getComdat());
660  cast<GlobalObject>(GV)->setComdat(nullptr);
661  }
662 
663  // Set the 'local' flag based on the linker resolution for this symbol.
665  GV->setDSOLocal(true);
666  }
667  // Common resolution: collect the maximum size/alignment over all commons.
668  // We also record if we see an instance of a common as prevailing, so that
669  // if none is prevailing we can ignore it later.
670  if (Sym.isCommon()) {
671  // FIXME: We should figure out what to do about commons defined by asm.
672  // For now they aren't reported correctly by ModuleSymbolTable.
673  auto &CommonRes = RegularLTO.Commons[Sym.getIRName()];
674  CommonRes.Size = std::max(CommonRes.Size, Sym.getCommonSize());
675  CommonRes.Align = std::max(CommonRes.Align, Sym.getCommonAlignment());
676  CommonRes.Prevailing |= Res.Prevailing;
677  }
678 
679  }
680  if (!M.getComdatSymbolTable().empty())
681  for (GlobalValue &GV : M.global_values())
682  handleNonPrevailingComdat(GV, NonPrevailingComdats);
683  assert(MsymI == MsymE);
684  return std::move(Mod);
685 }
686 
687 Error LTO::linkRegularLTO(RegularLTOState::AddedModule Mod,
688  bool LivenessFromIndex) {
689  std::vector<GlobalValue *> Keep;
690  for (GlobalValue *GV : Mod.Keep) {
691  if (LivenessFromIndex && !ThinLTO.CombinedIndex.isGUIDLive(GV->getGUID()))
692  continue;
693 
694  if (!GV->hasAvailableExternallyLinkage()) {
695  Keep.push_back(GV);
696  continue;
697  }
698 
699  // Only link available_externally definitions if we don't already have a
700  // definition.
701  GlobalValue *CombinedGV =
702  RegularLTO.CombinedModule->getNamedValue(GV->getName());
703  if (CombinedGV && !CombinedGV->isDeclaration())
704  continue;
705 
706  Keep.push_back(GV);
707  }
708 
709  return RegularLTO.Mover->move(std::move(Mod.M), Keep,
711  /* IsPerformingImport */ false);
712 }
713 
714 // Add a ThinLTO module to the link.
715 Error LTO::addThinLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
716  const SymbolResolution *&ResI,
717  const SymbolResolution *ResE) {
718  if (Error Err =
719  BM.readSummary(ThinLTO.CombinedIndex, BM.getModuleIdentifier(),
720  ThinLTO.ModuleMap.size()))
721  return Err;
722 
723  for (const InputFile::Symbol &Sym : Syms) {
724  assert(ResI != ResE);
725  SymbolResolution Res = *ResI++;
726 
727  if (!Sym.getIRName().empty()) {
729  Sym.getIRName(), GlobalValue::ExternalLinkage, ""));
730  if (Res.Prevailing) {
731  ThinLTO.PrevailingModuleForGUID[GUID] = BM.getModuleIdentifier();
732 
733  // For linker redefined symbols (via --wrap or --defsym) we want to
734  // switch the linkage to `weak` to prevent IPOs from happening.
735  // Find the summary in the module for this very GV and record the new
736  // linkage so that we can switch it when we import the GV.
737  if (Res.LinkerRedefined)
738  if (auto S = ThinLTO.CombinedIndex.findSummaryInModule(
739  GUID, BM.getModuleIdentifier()))
740  S->setLinkage(GlobalValue::WeakAnyLinkage);
741  }
742 
743  // If the linker resolved the symbol to a local definition then mark it
744  // as local in the summary for the module we are adding.
746  if (auto S = ThinLTO.CombinedIndex.findSummaryInModule(
747  GUID, BM.getModuleIdentifier())) {
748  S->setDSOLocal(true);
749  }
750  }
751  }
752  }
753 
754  if (!ThinLTO.ModuleMap.insert({BM.getModuleIdentifier(), BM}).second)
755  return make_error<StringError>(
756  "Expected at most one ThinLTO module per bitcode file",
758 
759  return Error::success();
760 }
761 
762 unsigned LTO::getMaxTasks() const {
763  CalledGetMaxTasks = true;
764  return RegularLTO.ParallelCodeGenParallelismLevel + ThinLTO.ModuleMap.size();
765 }
766 
768  // Compute "dead" symbols, we don't want to import/export these!
769  DenseSet<GlobalValue::GUID> GUIDPreservedSymbols;
770  DenseMap<GlobalValue::GUID, PrevailingType> GUIDPrevailingResolutions;
771  for (auto &Res : GlobalResolutions) {
772  // Normally resolution have IR name of symbol. We can do nothing here
773  // otherwise. See comments in GlobalResolution struct for more details.
774  if (Res.second.IRName.empty())
775  continue;
776 
777  GlobalValue::GUID GUID = GlobalValue::getGUID(
778  GlobalValue::dropLLVMManglingEscape(Res.second.IRName));
779 
780  if (Res.second.VisibleOutsideSummary && Res.second.Prevailing)
781  GUIDPreservedSymbols.insert(GlobalValue::getGUID(
782  GlobalValue::dropLLVMManglingEscape(Res.second.IRName)));
783 
784  GUIDPrevailingResolutions[GUID] =
785  Res.second.Prevailing ? PrevailingType::Yes : PrevailingType::No;
786  }
787 
788  auto isPrevailing = [&](GlobalValue::GUID G) {
789  auto It = GUIDPrevailingResolutions.find(G);
790  if (It == GUIDPrevailingResolutions.end())
792  return It->second;
793  };
794  computeDeadSymbols(ThinLTO.CombinedIndex, GUIDPreservedSymbols, isPrevailing);
795 
796  // Setup output file to emit statistics.
797  std::unique_ptr<ToolOutputFile> StatsFile = nullptr;
798  if (!Conf.StatsFile.empty()) {
799  EnableStatistics(false);
800  std::error_code EC;
801  StatsFile =
802  llvm::make_unique<ToolOutputFile>(Conf.StatsFile, EC, sys::fs::F_None);
803  if (EC)
804  return errorCodeToError(EC);
805  StatsFile->keep();
806  }
807 
808  Error Result = runRegularLTO(AddStream);
809  if (!Result)
810  Result = runThinLTO(AddStream, Cache);
811 
812  if (StatsFile)
813  PrintStatisticsJSON(StatsFile->os());
814 
815  return Result;
816 }
817 
818 Error LTO::runRegularLTO(AddStreamFn AddStream) {
819  for (auto &M : RegularLTO.ModsWithSummaries)
820  if (Error Err = linkRegularLTO(std::move(M),
821  /*LivenessFromIndex=*/true))
822  return Err;
823 
824  // Make sure commons have the right size/alignment: we kept the largest from
825  // all the prevailing when adding the inputs, and we apply it here.
826  const DataLayout &DL = RegularLTO.CombinedModule->getDataLayout();
827  for (auto &I : RegularLTO.Commons) {
828  if (!I.second.Prevailing)
829  // Don't do anything if no instance of this common was prevailing.
830  continue;
831  GlobalVariable *OldGV = RegularLTO.CombinedModule->getNamedGlobal(I.first);
832  if (OldGV && DL.getTypeAllocSize(OldGV->getValueType()) == I.second.Size) {
833  // Don't create a new global if the type is already correct, just make
834  // sure the alignment is correct.
835  OldGV->setAlignment(I.second.Align);
836  continue;
837  }
838  ArrayType *Ty =
839  ArrayType::get(Type::getInt8Ty(RegularLTO.Ctx), I.second.Size);
840  auto *GV = new GlobalVariable(*RegularLTO.CombinedModule, Ty, false,
843  GV->setAlignment(I.second.Align);
844  if (OldGV) {
846  GV->takeName(OldGV);
847  OldGV->eraseFromParent();
848  } else {
849  GV->setName(I.first);
850  }
851  }
852 
853  if (Conf.PreOptModuleHook &&
854  !Conf.PreOptModuleHook(0, *RegularLTO.CombinedModule))
855  return Error::success();
856 
857  if (!Conf.CodeGenOnly) {
858  for (const auto &R : GlobalResolutions) {
859  if (!R.second.isPrevailingIRSymbol())
860  continue;
861  if (R.second.Partition != 0 &&
862  R.second.Partition != GlobalResolution::External)
863  continue;
864 
865  GlobalValue *GV =
866  RegularLTO.CombinedModule->getNamedValue(R.second.IRName);
867  // Ignore symbols defined in other partitions.
868  if (!GV || GV->hasLocalLinkage())
869  continue;
870  GV->setUnnamedAddr(R.second.UnnamedAddr ? GlobalValue::UnnamedAddr::Global
872  if (R.second.Partition == 0)
874  }
875 
876  if (Conf.PostInternalizeModuleHook &&
877  !Conf.PostInternalizeModuleHook(0, *RegularLTO.CombinedModule))
878  return Error::success();
879  }
880  return backend(Conf, AddStream, RegularLTO.ParallelCodeGenParallelismLevel,
881  std::move(RegularLTO.CombinedModule), ThinLTO.CombinedIndex);
882 }
883 
884 /// This class defines the interface to the ThinLTO backend.
886 protected:
890 
891 public:
893  const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries)
894  : Conf(Conf), CombinedIndex(CombinedIndex),
895  ModuleToDefinedGVSummaries(ModuleToDefinedGVSummaries) {}
896 
897  virtual ~ThinBackendProc() {}
898  virtual Error start(
899  unsigned Task, BitcodeModule BM,
900  const FunctionImporter::ImportMapTy &ImportList,
901  const FunctionImporter::ExportSetTy &ExportList,
902  const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
903  MapVector<StringRef, BitcodeModule> &ModuleMap) = 0;
904  virtual Error wait() = 0;
905 };
906 
907 namespace {
908 class InProcessThinBackend : public ThinBackendProc {
909  ThreadPool BackendThreadPool;
910  AddStreamFn AddStream;
911  NativeObjectCache Cache;
912  TypeIdSummariesByGuidTy TypeIdSummariesByGuid;
913  std::set<GlobalValue::GUID> CfiFunctionDefs;
914  std::set<GlobalValue::GUID> CfiFunctionDecls;
915 
916  Optional<Error> Err;
917  std::mutex ErrMu;
918 
919 public:
920  InProcessThinBackend(
921  Config &Conf, ModuleSummaryIndex &CombinedIndex,
922  unsigned ThinLTOParallelismLevel,
923  const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
924  AddStreamFn AddStream, NativeObjectCache Cache)
925  : ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries),
926  BackendThreadPool(ThinLTOParallelismLevel),
927  AddStream(std::move(AddStream)), Cache(std::move(Cache)) {
928  // Create a mapping from type identifier GUIDs to type identifier summaries.
929  // This allows backends to use the type identifier GUIDs stored in the
930  // function summaries to determine which type identifier summaries affect
931  // each function without needing to compute GUIDs in each backend.
932  for (auto &TId : CombinedIndex.typeIds())
933  TypeIdSummariesByGuid[GlobalValue::getGUID(TId.first)].push_back(&TId);
934  for (auto &Name : CombinedIndex.cfiFunctionDefs())
935  CfiFunctionDefs.insert(
937  for (auto &Name : CombinedIndex.cfiFunctionDecls())
938  CfiFunctionDecls.insert(
940  }
941 
942  Error runThinLTOBackendThread(
943  AddStreamFn AddStream, NativeObjectCache Cache, unsigned Task,
944  BitcodeModule BM, ModuleSummaryIndex &CombinedIndex,
945  const FunctionImporter::ImportMapTy &ImportList,
946  const FunctionImporter::ExportSetTy &ExportList,
947  const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
948  const GVSummaryMapTy &DefinedGlobals,
950  const TypeIdSummariesByGuidTy &TypeIdSummariesByGuid) {
951  auto RunThinBackend = [&](AddStreamFn AddStream) {
952  LTOLLVMContext BackendContext(Conf);
953  Expected<std::unique_ptr<Module>> MOrErr = BM.parseModule(BackendContext);
954  if (!MOrErr)
955  return MOrErr.takeError();
956 
957  return thinBackend(Conf, Task, AddStream, **MOrErr, CombinedIndex,
958  ImportList, DefinedGlobals, ModuleMap);
959  };
960 
961  auto ModuleID = BM.getModuleIdentifier();
962 
963  if (!Cache || !CombinedIndex.modulePaths().count(ModuleID) ||
964  all_of(CombinedIndex.getModuleHash(ModuleID),
965  [](uint32_t V) { return V == 0; }))
966  // Cache disabled or no entry for this module in the combined index or
967  // no module hash.
968  return RunThinBackend(AddStream);
969 
971  // The module may be cached, this helps handling it.
972  computeCacheKey(Key, Conf, CombinedIndex, ModuleID, ImportList, ExportList,
973  ResolvedODR, DefinedGlobals, TypeIdSummariesByGuid,
974  CfiFunctionDefs, CfiFunctionDecls);
975  if (AddStreamFn CacheAddStream = Cache(Task, Key))
976  return RunThinBackend(CacheAddStream);
977 
978  return Error::success();
979  }
980 
981  Error start(
982  unsigned Task, BitcodeModule BM,
983  const FunctionImporter::ImportMapTy &ImportList,
984  const FunctionImporter::ExportSetTy &ExportList,
985  const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
986  MapVector<StringRef, BitcodeModule> &ModuleMap) override {
987  StringRef ModulePath = BM.getModuleIdentifier();
988  assert(ModuleToDefinedGVSummaries.count(ModulePath));
989  const GVSummaryMapTy &DefinedGlobals =
990  ModuleToDefinedGVSummaries.find(ModulePath)->second;
991  BackendThreadPool.async(
992  [=](BitcodeModule BM, ModuleSummaryIndex &CombinedIndex,
993  const FunctionImporter::ImportMapTy &ImportList,
994  const FunctionImporter::ExportSetTy &ExportList,
995  const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>
996  &ResolvedODR,
997  const GVSummaryMapTy &DefinedGlobals,
999  const TypeIdSummariesByGuidTy &TypeIdSummariesByGuid) {
1000  Error E = runThinLTOBackendThread(
1001  AddStream, Cache, Task, BM, CombinedIndex, ImportList, ExportList,
1002  ResolvedODR, DefinedGlobals, ModuleMap, TypeIdSummariesByGuid);
1003  if (E) {
1004  std::unique_lock<std::mutex> L(ErrMu);
1005  if (Err)
1006  Err = joinErrors(std::move(*Err), std::move(E));
1007  else
1008  Err = std::move(E);
1009  }
1010  },
1011  BM, std::ref(CombinedIndex), std::ref(ImportList), std::ref(ExportList),
1012  std::ref(ResolvedODR), std::ref(DefinedGlobals), std::ref(ModuleMap),
1013  std::ref(TypeIdSummariesByGuid));
1014  return Error::success();
1015  }
1016 
1017  Error wait() override {
1018  BackendThreadPool.wait();
1019  if (Err)
1020  return std::move(*Err);
1021  else
1022  return Error::success();
1023  }
1024 };
1025 } // end anonymous namespace
1026 
1027 ThinBackend lto::createInProcessThinBackend(unsigned ParallelismLevel) {
1028  return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex,
1029  const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
1030  AddStreamFn AddStream, NativeObjectCache Cache) {
1031  return llvm::make_unique<InProcessThinBackend>(
1032  Conf, CombinedIndex, ParallelismLevel, ModuleToDefinedGVSummaries,
1033  AddStream, Cache);
1034  };
1035 }
1036 
1037 // Given the original \p Path to an output file, replace any path
1038 // prefix matching \p OldPrefix with \p NewPrefix. Also, create the
1039 // resulting directory if it does not yet exist.
1040 std::string lto::getThinLTOOutputFile(const std::string &Path,
1041  const std::string &OldPrefix,
1042  const std::string &NewPrefix) {
1043  if (OldPrefix.empty() && NewPrefix.empty())
1044  return Path;
1045  SmallString<128> NewPath(Path);
1046  llvm::sys::path::replace_path_prefix(NewPath, OldPrefix, NewPrefix);
1047  StringRef ParentPath = llvm::sys::path::parent_path(NewPath.str());
1048  if (!ParentPath.empty()) {
1049  // Make sure the new directory exists, creating it if necessary.
1050  if (std::error_code EC = llvm::sys::fs::create_directories(ParentPath))
1051  llvm::errs() << "warning: could not create directory '" << ParentPath
1052  << "': " << EC.message() << '\n';
1053  }
1054  return NewPath.str();
1055 }
1056 
1057 namespace {
1058 class WriteIndexesThinBackend : public ThinBackendProc {
1059  std::string OldPrefix, NewPrefix;
1060  bool ShouldEmitImportsFiles;
1061  raw_fd_ostream *LinkedObjectsFile;
1062  lto::IndexWriteCallback OnWrite;
1063 
1064 public:
1065  WriteIndexesThinBackend(
1066  Config &Conf, ModuleSummaryIndex &CombinedIndex,
1067  const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
1068  std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles,
1069  raw_fd_ostream *LinkedObjectsFile, lto::IndexWriteCallback OnWrite)
1070  : ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries),
1071  OldPrefix(OldPrefix), NewPrefix(NewPrefix),
1072  ShouldEmitImportsFiles(ShouldEmitImportsFiles),
1073  LinkedObjectsFile(LinkedObjectsFile), OnWrite(OnWrite) {}
1074 
1075  Error start(
1076  unsigned Task, BitcodeModule BM,
1077  const FunctionImporter::ImportMapTy &ImportList,
1078  const FunctionImporter::ExportSetTy &ExportList,
1079  const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
1080  MapVector<StringRef, BitcodeModule> &ModuleMap) override {
1081  StringRef ModulePath = BM.getModuleIdentifier();
1082  std::string NewModulePath =
1083  getThinLTOOutputFile(ModulePath, OldPrefix, NewPrefix);
1084 
1085  if (LinkedObjectsFile)
1086  *LinkedObjectsFile << NewModulePath << '\n';
1087 
1088  std::map<std::string, GVSummaryMapTy> ModuleToSummariesForIndex;
1089  gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries,
1090  ImportList, ModuleToSummariesForIndex);
1091 
1092  std::error_code EC;
1093  raw_fd_ostream OS(NewModulePath + ".thinlto.bc", EC,
1095  if (EC)
1096  return errorCodeToError(EC);
1097  WriteIndexToFile(CombinedIndex, OS, &ModuleToSummariesForIndex);
1098 
1099  if (ShouldEmitImportsFiles) {
1100  EC = EmitImportsFiles(ModulePath, NewModulePath + ".imports",
1101  ModuleToSummariesForIndex);
1102  if (EC)
1103  return errorCodeToError(EC);
1104  }
1105 
1106  if (OnWrite)
1107  OnWrite(ModulePath);
1108  return Error::success();
1109  }
1110 
1111  Error wait() override { return Error::success(); }
1112 };
1113 } // end anonymous namespace
1114 
1116  std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles,
1117  raw_fd_ostream *LinkedObjectsFile, IndexWriteCallback OnWrite) {
1118  return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex,
1119  const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
1120  AddStreamFn AddStream, NativeObjectCache Cache) {
1121  return llvm::make_unique<WriteIndexesThinBackend>(
1122  Conf, CombinedIndex, ModuleToDefinedGVSummaries, OldPrefix, NewPrefix,
1123  ShouldEmitImportsFiles, LinkedObjectsFile, OnWrite);
1124  };
1125 }
1126 
1127 Error LTO::runThinLTO(AddStreamFn AddStream, NativeObjectCache Cache) {
1128  if (ThinLTO.ModuleMap.empty())
1129  return Error::success();
1130 
1131  if (Conf.CombinedIndexHook && !Conf.CombinedIndexHook(ThinLTO.CombinedIndex))
1132  return Error::success();
1133 
1134  // Collect for each module the list of function it defines (GUID ->
1135  // Summary).
1137  ModuleToDefinedGVSummaries(ThinLTO.ModuleMap.size());
1138  ThinLTO.CombinedIndex.collectDefinedGVSummariesPerModule(
1139  ModuleToDefinedGVSummaries);
1140  // Create entries for any modules that didn't have any GV summaries
1141  // (either they didn't have any GVs to start with, or we suppressed
1142  // generation of the summaries because they e.g. had inline assembly
1143  // uses that couldn't be promoted/renamed on export). This is so
1144  // InProcessThinBackend::start can still launch a backend thread, which
1145  // is passed the map of summaries for the module, without any special
1146  // handling for this case.
1147  for (auto &Mod : ThinLTO.ModuleMap)
1148  if (!ModuleToDefinedGVSummaries.count(Mod.first))
1149  ModuleToDefinedGVSummaries.try_emplace(Mod.first);
1150 
1152  ThinLTO.ModuleMap.size());
1154  ThinLTO.ModuleMap.size());
1156 
1157  if (DumpThinCGSCCs)
1158  ThinLTO.CombinedIndex.dumpSCCs(outs());
1159 
1160  if (Conf.OptLevel > 0)
1161  ComputeCrossModuleImport(ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries,
1162  ImportLists, ExportLists);
1163 
1164  // Figure out which symbols need to be internalized. This also needs to happen
1165  // at -O0 because summary-based DCE is implemented using internalization, and
1166  // we must apply DCE consistently with the full LTO module in order to avoid
1167  // undefined references during the final link.
1168  std::set<GlobalValue::GUID> ExportedGUIDs;
1169  for (auto &Res : GlobalResolutions) {
1170  // If the symbol does not have external references or it is not prevailing,
1171  // then not need to mark it as exported from a ThinLTO partition.
1172  if (Res.second.Partition != GlobalResolution::External ||
1173  !Res.second.isPrevailingIRSymbol())
1174  continue;
1175  auto GUID = GlobalValue::getGUID(
1176  GlobalValue::dropLLVMManglingEscape(Res.second.IRName));
1177  // Mark exported unless index-based analysis determined it to be dead.
1178  if (ThinLTO.CombinedIndex.isGUIDLive(GUID))
1179  ExportedGUIDs.insert(GUID);
1180  }
1181 
1182  // Any functions referenced by the jump table in the regular LTO object must
1183  // be exported.
1184  for (auto &Def : ThinLTO.CombinedIndex.cfiFunctionDefs())
1185  ExportedGUIDs.insert(
1187 
1188  auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) {
1189  const auto &ExportList = ExportLists.find(ModuleIdentifier);
1190  return (ExportList != ExportLists.end() &&
1191  ExportList->second.count(GUID)) ||
1192  ExportedGUIDs.count(GUID);
1193  };
1194  thinLTOInternalizeAndPromoteInIndex(ThinLTO.CombinedIndex, isExported);
1195 
1196  auto isPrevailing = [&](GlobalValue::GUID GUID,
1197  const GlobalValueSummary *S) {
1198  return ThinLTO.PrevailingModuleForGUID[GUID] == S->modulePath();
1199  };
1200  auto recordNewLinkage = [&](StringRef ModuleIdentifier,
1201  GlobalValue::GUID GUID,
1202  GlobalValue::LinkageTypes NewLinkage) {
1203  ResolvedODR[ModuleIdentifier][GUID] = NewLinkage;
1204  };
1205  thinLTOResolveWeakForLinkerInIndex(ThinLTO.CombinedIndex, isPrevailing,
1206  recordNewLinkage);
1207 
1208  std::unique_ptr<ThinBackendProc> BackendProc =
1209  ThinLTO.Backend(Conf, ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries,
1210  AddStream, Cache);
1211 
1212  // Tasks 0 through ParallelCodeGenParallelismLevel-1 are reserved for combined
1213  // module and parallel code generation partitions.
1214  unsigned Task = RegularLTO.ParallelCodeGenParallelismLevel;
1215  for (auto &Mod : ThinLTO.ModuleMap) {
1216  if (Error E = BackendProc->start(Task, Mod.second, ImportLists[Mod.first],
1217  ExportLists[Mod.first],
1218  ResolvedODR[Mod.first], ThinLTO.ModuleMap))
1219  return E;
1220  ++Task;
1221  }
1222 
1223  return BackendProc->wait();
1224 }
1225 
1229  bool LTOPassRemarksWithHotness, int Count) {
1230  if (LTOPassRemarksWithHotness)
1231  Context.setDiagnosticsHotnessRequested(true);
1232  if (LTORemarksFilename.empty())
1233  return nullptr;
1234 
1235  std::string Filename = LTORemarksFilename;
1236  if (Count != -1)
1237  Filename += ".thin." + llvm::utostr(Count) + ".yaml";
1238 
1239  std::error_code EC;
1240  auto DiagnosticFile =
1241  llvm::make_unique<ToolOutputFile>(Filename, EC, sys::fs::F_None);
1242  if (EC)
1243  return errorCodeToError(EC);
1244  Context.setDiagnosticsOutputFile(
1245  llvm::make_unique<yaml::Output>(DiagnosticFile->os()));
1246  DiagnosticFile->keep();
1247  return std::move(DiagnosticFile);
1248 }
uint64_t CallInst * C
std::error_code create_directories(const Twine &path, bool IgnoreExisting=true, perms Perms=owner_all|group_all)
Create all the non-existent directories in path.
Definition: Path.cpp:906
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:111
ArrayRef< Symbol > symbols() const
A range over the symbols in this InputFile.
Definition: LTO.h:133
static void thinLTOResolveWeakForLinkerGUID(GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID, DenseSet< GlobalValueSummary *> &GlobalInvolvedWithAlias, function_ref< bool(GlobalValue::GUID, const GlobalValueSummary *)> isPrevailing, function_ref< void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)> recordNewLinkage)
Definition: LTO.cpp:281
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
Expected< std::unique_ptr< ToolOutputFile > > setupOptimizationRemarks(LLVMContext &Context, StringRef LTORemarksFilename, bool LTOPassRemarksWithHotness, int Count=-1)
Setup optimization remarks.
Definition: LTO.cpp:1227
This class defines the interface to the ThinLTO backend.
Definition: LTO.cpp:885
bool hasLocalLinkage() const
Definition: GlobalValue.h:435
std::string CPU
Definition: Config.h:39
std::string AAPipeline
Definition: Config.h:63
uint32_t getSymbolFlags(Symbol S) const
GCNRegPressure max(const GCNRegPressure &P1, const GCNRegPressure &P2)
void EnableStatistics(bool PrintOnExit=true)
Enable the collection and printing of statistics.
Definition: Statistic.cpp:129
LLVMContext & Context
unsigned Prevailing
The linker has chosen this definition of the symbol.
Definition: LTO.h:400
CodeGenOpt::Level CGOptLevel
Definition: Config.h:44
void replace_path_prefix(SmallVectorImpl< char > &Path, const StringRef &OldPrefix, const StringRef &NewPrefix, Style style=Style::native)
Replace matching path prefix with another path.
Definition: Path.cpp:515
std::vector< std::unique_ptr< GlobalValueSummary > > GlobalValueSummaryList
uint64_t GUID
Declare a type to represent a global unique identifier for a global value.
Definition: GlobalValue.h:492
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
void setDiagnosticsOutputFile(std::unique_ptr< yaml::Output > F)
Set the diagnostics output file used for optimization diagnostics.
cl::opt< std::string > LTORemarksFilename("lto-pass-remarks-output", cl::desc("Output filename for pass remarks"), cl::value_desc("filename"))
unsigned heavyweight_hardware_concurrency()
Get the amount of currency to use for tasks requiring significant memory or other resources...
Definition: Threading.cpp:63
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:63
iterator begin() const
Definition: ArrayRef.h:137
GlobalValueSummary * findSummaryInModule(GlobalValue::GUID ValueGUID, StringRef ModuleId) const
Find the summary for global GUID in module ModuleId, or nullptr if not found.
The purpose of this class is to only expose the symbol information that an LTO client should need in ...
Definition: LTO.h:110
Implements a dense probed hash-table based set.
Definition: DenseSet.h:221
std::string OverrideTriple
Setting this field will replace target triples in input files with this triple.
Definition: Config.h:67
Available for inspection, not emission.
Definition: GlobalValue.h:50
unsigned DataSections
Emit data into separate sections.
static ConstantAggregateZero * get(Type *Ty)
Definition: Constants.cpp:1309
std::error_code EmitImportsFiles(StringRef ModulePath, StringRef OutputFilename, const std::map< std::string, GVSummaryMapTy > &ModuleToSummariesForIndex)
Emit into OutputFilename the files module ModulePath will import from.
bool CodeGenOnly
Disable entirely the optimizer, including importing for ThinLTO.
Definition: Config.h:53
Error readSummary(ModuleSummaryIndex &CombinedIndex, StringRef ModulePath, uint64_t ModuleId)
Parse the specified bitcode buffer and merge its module summary index into CombinedIndex.
bool hasAvailableExternallyLinkage() const
Definition: GlobalValue.h:422
This file contains the declarations for metadata subclasses.
unsigned LinkerRedefined
Linker redefined version of the symbol which appeared in -wrap or -defsym linker option.
Definition: LTO.h:411
std::unique_ptr< raw_ostream > ResolutionFile
If this field is set, LTO will write input file paths and symbol resolutions here in llvm-lto2 comman...
Definition: Config.h:103
static void computeCacheKey(SmallString< 40 > &Key, const Config &Conf, const ModuleSummaryIndex &Index, StringRef ModuleID, const FunctionImporter::ImportMapTy &ImportList, const FunctionImporter::ExportSetTy &ExportList, const std::map< GlobalValue::GUID, GlobalValue::LinkageTypes > &ResolvedODR, const GVSummaryMapTy &DefinedGlobals, const TypeIdSummariesByGuidTy &TypeIdSummariesByGuid, const std::set< GlobalValue::GUID > &CfiFunctionDefs, const std::set< GlobalValue::GUID > &CfiFunctionDecls)
Definition: LTO.cpp:68
An efficient, type-erasing, non-owning reference to a callable.
Definition: STLExtras.h:93
iterator find(StringRef Key)
Definition: StringMap.h:333
const StringMap< std::pair< uint64_t, ModuleHash > > & modulePaths() const
Table of modules, containing module hash and id.
Externally visible function.
Definition: GlobalValue.h:49
The resolution for a symbol.
Definition: LTO.h:394
This class implements a map that also provides access to all stored values in a deterministic order...
Definition: MapVector.h:38
bool all_of(R &&range, UnaryPredicate P)
Provide wrappers to std::all_of which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:908
F(f)
const StringMap< GVSummaryMapTy > & ModuleToDefinedGVSummaries
Definition: LTO.cpp:889
A class that wrap the SHA1 algorithm.
Definition: SHA1.h:29
static Expected< std::unique_ptr< InputFile > > create(MemoryBufferRef Object)
Create an InputFile.
Definition: LTO.cpp:365
Error takeError()
Take ownership of the stored error.
Definition: Error.h:545
std::string getGlobalIdentifier() const
Return the modified name for this global value suitable to be used as the key for a global lookup (e...
Definition: Globals.cpp:151
void setAlignment(unsigned Align)
Definition: Globals.cpp:111
std::function< void(const std::string &)> IndexWriteCallback
This ThinBackend writes individual module indexes to files, instead of running the individual backend...
Definition: LTO.h:216
std::shared_future< void > async(Function &&F, Args &&... ArgList)
Asynchronous submission of a task to the pool.
Definition: ThreadPool.h:55
TinyPtrVector - This class is specialized for cases where there are normally 0 or 1 element in a vect...
Definition: TinyPtrVector.h:31
StringRef getModuleIdentifier() const
Definition: BitcodeReader.h:92
Tentative definitions.
Definition: GlobalValue.h:59
ThinBackend createWriteIndexesThinBackend(std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles, raw_fd_ostream *LinkedObjectsFile, IndexWriteCallback OnWrite)
Definition: LTO.cpp:1115
static bool isLocalLinkage(LinkageTypes Linkage)
Definition: GlobalValue.h:320
static bool isLinkOnceLinkage(LinkageTypes Linkage)
Definition: GlobalValue.h:299
CombinedIndexHookFn CombinedIndexHook
Definition: Config.h:164
std::pair< iterator, bool > insert(const std::pair< KeyT, ValueT > &KV)
Definition: DenseMap.h:191
StringRef getName() const
Returns the path to the InputFile.
Definition: LTO.cpp:393
std::function< std::unique_ptr< NativeObjectStream >unsigned Task)> AddStreamFn
This type defines the callback to add a native object that is generated on the fly.
Definition: LTO.h:174
Definition: BitVector.h:921
Represents a module in a bitcode file.
Definition: BitcodeReader.h:57
std::string DwoDir
The directory to store .dwo files.
Definition: Config.h:77
const ComdatSymTabType & getComdatSymbolTable() const
Get the Module&#39;s symbol table for COMDATs (constant).
Definition: Module.h:552
std::vector< std::string > MAttrs
Definition: Config.h:41
ModuleSummaryIndex & CombinedIndex
Definition: LTO.cpp:888
std::unordered_set< GlobalValue::GUID > ExportSetTy
The set contains an entry for every global value the module exports.
ArrayRef< Symbol > symbols() const
Tagged union holding either a T or a Error.
Definition: CachePruning.h:23
StringRef result()
Return a reference to the current raw 160-bits SHA1 for the digested data since the last call to init...
Definition: SHA1.cpp:261
static bool isLinkOnceODRLinkage(LinkageTypes Linkage)
Definition: GlobalValue.h:296
StringRef str() const
Explicit conversion to StringRef.
Definition: SmallString.h:267
Key
PAL metadata keys.
const std::map< std::string, TypeIdSummary > & typeIds() const
cl::opt< bool > LTOPassRemarksWithHotness("lto-pass-remarks-with-hotness", cl::desc("With PGO, include profile count in optimization remarks"), cl::Hidden)
void setDiagnosticsHotnessRequested(bool Requested)
Set if a code hotness metric should be included in optimization diagnostics.
Class to represent array types.
Definition: DerivedTypes.h:369
std::string SampleProfile
Sample PGO profile path.
Definition: Config.h:74
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:133
TargetOptions Options
Definition: Config.h:40
unsigned FunctionSections
Emit functions into separate sections.
Optional< CodeModel::Model > CodeModel
Definition: Config.h:43
SmallString - A SmallString is just a SmallVector with methods and accessors that make it work better...
Definition: SmallString.h:26
An input file.
Definition: LTO.h:83
A ThreadPool for asynchronous parallel execution on a defined number of threads.
Definition: ThreadPool.h:37
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp:439
std::pair< iterator, bool > try_emplace(StringRef Key, ArgsTy &&... Args)
Emplace a new element for the specified key into the map if the key isn&#39;t already in the map...
Definition: StringMap.h:395
Class to hold module path string table and global value map, and encapsulate methods for operating on...
void update(ArrayRef< uint8_t > Data)
Digest more data.
Definition: SHA1.cpp:213
iterator find(const_arg_type_t< KeyT > Val)
Definition: DenseMap.h:146
static Constant * getBitCast(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1750
Ephemeral symbols produced by Reader::symbols() and Reader::module_symbols().
Definition: IRSymtab.h:291
Error add(std::unique_ptr< InputFile > Obj, ArrayRef< SymbolResolution > Res)
Add an input file to the LTO link, using the provided symbol resolutions.
Definition: LTO.cpp:491
DebuggerKind DebuggerTuning
Which debugger to tune for.
raw_ostream & outs()
This returns a reference to a raw_ostream for standard output.
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:410
ModuleHookFn PreOptModuleHook
This module hook is called after linking (regular LTO) or loading (ThinLTO) the module, before modifying it.
Definition: Config.h:133
static cl::opt< bool > DumpThinCGSCCs("dump-thin-cg-sccs", cl::init(false), cl::Hidden, cl::desc("Dump the SCCs in the ThinLTO index's callgraph"))
std::function< AddStreamFn(unsigned Task, StringRef Key)> NativeObjectCache
This is the type of a native object cache.
Definition: LTO.h:189
void gatherImportedSummariesForModule(StringRef ModulePath, const StringMap< GVSummaryMapTy > &ModuleToDefinedGVSummaries, const FunctionImporter::ImportMapTy &ImportList, std::map< std::string, GVSummaryMapTy > &ModuleToSummariesForIndex)
Compute the set of summaries needed for a ThinLTO backend compilation of ModulePath.
size_type count(StringRef Key) const
count - Return 1 if the element is in the map, 0 otherwise.
Definition: StringMap.h:359
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:69
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
Error errorCodeToError(std::error_code EC)
Helper for converting an std::error_code to a Error.
Definition: Error.cpp:78
bool UseNewPM
Use the new pass manager.
Definition: Config.h:50
bool UpgradeDebugInfo(Module &M)
Check the debug info version number, if it is out-dated, drop the debug info.
ThinBackendProc(Config &Conf, ModuleSummaryIndex &CombinedIndex, const StringMap< GVSummaryMapTy > &ModuleToDefinedGVSummaries)
Definition: LTO.cpp:892
unsigned OptLevel
Definition: Config.h:46
void eraseFromParent()
eraseFromParent - This method unlinks &#39;this&#39; from the containing module and deletes it...
Definition: Globals.cpp:354
DenseMap< GlobalValue::GUID, TinyPtrVector< const std::pair< const std::string, TypeIdSummary > * > > TypeIdSummariesByGuidTy
Definition: LTO.cpp:63
bool isWeakForLinker() const
Definition: GlobalValue.h:456
LTO configuration.
Definition: Config.h:36
std::string DefaultTriple
Setting this field will replace unspecified target triples in input files with this triple...
Definition: Config.h:71
const ModuleHash & getModuleHash(const StringRef ModPath) const
Get the module SHA1 hash recorded for the given module path.
StringRef parent_path(StringRef path, Style style=Style::native)
Get parent path.
Definition: Path.cpp:482
Function and variable summary information to aid decisions and implementation of importing.
static GUID getGUID(StringRef GlobalName)
Return a 64-bit global unique ID constructed from global value name (i.e.
Definition: GlobalValue.h:496
std::string StatsFile
Statistics output file path.
Definition: Config.h:94
T dyn_cast() const
Returns the current pointer if it is of the specified pointer type, otherwises returns null...
Definition: PointerUnion.h:142
ModuleHookFn PostInternalizeModuleHook
This hook is called after internalizing the module.
Definition: Config.h:140
const AMDGPUAS & AS
TargetMachine::CodeGenFileType CGFileType
Definition: Config.h:45
static LinkageTypes getWeakLinkage(bool ODR)
Definition: GlobalValue.h:286
Struct that holds a reference to a particular GUID in a global value summary.
static void writeToResolutionFile(raw_ostream &OS, InputFile *Input, ArrayRef< SymbolResolution > Res)
Definition: LTO.cpp:467
void PrintStatisticsJSON(raw_ostream &OS)
Print statistics in JSON format.
Definition: Statistic.cpp:203
static ErrorSuccess success()
Create a success value.
Definition: Error.h:321
std::function< std::unique_ptr< ThinBackendProc > Config &C, ModuleSummaryIndex &CombinedIndex, StringMap< GVSummaryMapTy > &ModuleToDefinedGVSummaries, AddStreamFn AddStream, NativeObjectCache Cache)> ThinBackend
A ThinBackend defines what happens after the thin-link phase during ThinLTO.
Definition: LTO.h:198
unsigned getMaxTasks() const
Returns an upper bound on the number of tasks that the client may expect.
Definition: LTO.cpp:762
static void thinLTOInternalizeAndPromoteGUID(GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID, function_ref< bool(StringRef, GlobalValue::GUID)> isExported)
Definition: LTO.cpp:341
iterator end() const
Definition: ArrayRef.h:138
const DataFlowGraph & G
Definition: RDFGraph.cpp:211
virtual ~ThinBackendProc()
Definition: LTO.cpp:897
Optional< Reloc::Model > RelocModel
Definition: Config.h:42
std::string utostr(uint64_t X, bool isNeg=false)
Definition: StringExtras.h:214
void setLinkage(LinkageTypes LT)
Definition: GlobalValue.h:444
The access may modify the value stored in memory.
StringMap - This is an unconventional map that is specialized for handling keys that are "strings"...
Definition: StringMap.h:220
const Comdat * getComdat() const
Definition: Globals.cpp:166
static StringRef dropLLVMManglingEscape(StringRef Name)
If the given string begins with the GlobalValue name mangling escape character &#39;\1&#39;, drop it.
Definition: GlobalValue.h:471
LinkageTypes
An enumeration for the kinds of linkage for global values.
Definition: GlobalValue.h:48
std::string OptPipeline
If this field is set, the set of passes run in the middle-end optimizer will be the one specified by ...
Definition: Config.h:58
void WriteIndexToFile(const ModuleSummaryIndex &Index, raw_ostream &Out, const std::map< std::string, GVSummaryMapTy > *ModuleToSummariesForIndex=nullptr)
Write the specified module summary index to the given raw output stream, where it will be written in ...
std::string toHex(StringRef Input)
Convert buffer Input to its hexadecimal representation.
Definition: StringExtras.h:133
GUID getGUID() const
Return a 64-bit global unique ID constructed from global value name (i.e.
Definition: GlobalValue.h:500
unsigned RelaxELFRelocations
ThinBackend createInProcessThinBackend(unsigned ParallelismLevel)
This ThinBackend runs the individual backend jobs in-process.
Definition: LTO.cpp:1027
amdgpu Simplify well known AMD library false Value Value * Arg
uint64_t getTypeAllocSize(Type *Ty) const
Returns the offset in bytes between successive objects of the specified type, including alignment pad...
Definition: DataLayout.h:428
std::set< std::string > & cfiFunctionDefs()
Error thinBackend(Config &C, unsigned Task, AddStreamFn AddStream, Module &M, const ModuleSummaryIndex &CombinedIndex, const FunctionImporter::ImportMapTy &ImportList, const GVSummaryMapTy &DefinedGlobals, MapVector< StringRef, BitcodeModule > &ModuleMap)
Runs a ThinLTO backend.
Definition: LTOBackend.cpp:452
void ComputeCrossModuleImport(const ModuleSummaryIndex &Index, const StringMap< GVSummaryMapTy > &ModuleToDefinedGVSummaries, StringMap< FunctionImporter::ImportMapTy > &ImportLists, StringMap< FunctionImporter::ExportSetTy > &ExportLists)
Compute all the imports and exports for every module in the Index.
A raw_ostream that writes to a file descriptor.
Definition: raw_ostream.h:366
LTO(Config Conf, ThinBackend Backend=nullptr, unsigned ParallelCodeGenParallelismLevel=1)
Create an LTO object.
Definition: LTO.cpp:410
void setUnnamedAddr(UnnamedAddr Val)
Definition: GlobalValue.h:215
void thinLTOResolveWeakForLinkerInIndex(ModuleSummaryIndex &Index, function_ref< bool(GlobalValue::GUID, const GlobalValueSummary *)> isPrevailing, function_ref< void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)> recordNewLinkage)
Resolve Weak and LinkOnce values in the Index.
Definition: LTO.cpp:320
static void handleNonPrevailingComdat(GlobalValue &GV, std::set< const Comdat *> &NonPrevailingComdats)
Definition: LTO.cpp:553
Error joinErrors(Error E1, Error E2)
Concatenate errors.
Definition: Error.h:416
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:224
#define I(x, y, z)
Definition: MD5.cpp:58
Error run(AddStreamFn AddStream, NativeObjectCache Cache=nullptr)
Runs the LTO pipeline.
Definition: LTO.cpp:767
iterator end()
Definition: DenseMap.h:79
static ArrayType * get(Type *ElementType, uint64_t NumElements)
This static method is the primary way to construct an ArrayType.
Definition: Type.cpp:568
Type * getValueType() const
Definition: GlobalValue.h:275
Keep one copy of named function when linking (weak)
Definition: GlobalValue.h:53
Rename collisions when linking (static functions).
Definition: GlobalValue.h:56
size_type count(const_arg_type_t< ValueT > V) const
Return 1 if the specified key is in the set, 0 otherwise.
Definition: DenseSet.h:91
unsigned VisibleToRegularObj
The definition of this symbol is visible outside of the LTO unit.
Definition: LTO.h:407
bool isDeclaration() const
Return true if the primary definition of this global value is outside of the current translation unit...
Definition: Globals.cpp:201
const GlobalObject * getBaseObject() const
Definition: Globals.cpp:256
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFile(const Twine &Filename, int64_t FileSize=-1, bool RequiresNullTerminator=true, bool IsVolatile=false)
Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful, otherwise returning null.
Error backend(Config &C, AddStreamFn AddStream, unsigned ParallelCodeGenParallelismLevel, std::unique_ptr< Module > M, ModuleSummaryIndex &CombinedIndex)
Runs a regular LTO backend.
Definition: LTOBackend.cpp:399
bool empty() const
Definition: StringMap.h:111
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
std::set< std::string > & cfiFunctionDecls()
std::function< void(GlobalValue &)> ValueAdder
Definition: IRMover.h:65
Lightweight error class with error context and mandatory checking.
Definition: Error.h:156
void computeDeadSymbols(ModuleSummaryIndex &Index, const DenseSet< GlobalValue::GUID > &GUIDPreservedSymbols, function_ref< PrevailingType(GlobalValue::GUID)> isPrevailing)
Compute all the symbols that are "dead": i.e these that can&#39;t be reached in the graph from any of the...
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:46
Expected< std::unique_ptr< Module > > getLazyModule(LLVMContext &Context, bool ShouldLazyLoadMetadata, bool IsImporting)
Read the bitcode module and prepare for lazy deserialization of function bodies.
Expected< std::unique_ptr< Module > > parseModule(LLVMContext &Context)
Read the entire bitcode module and return it.
iterator_range< global_iterator > globals()
Definition: Module.h:566
A derived class of LLVMContext that initializes itself according to a given Config object...
Definition: Config.h:199
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
This pass exposes codegen information to IR-level passes.
unsigned FinalDefinitionInLinkageUnit
The definition of this symbol is unpreemptable at runtime and is known to be in this linkage unit...
Definition: LTO.h:404
Expected< IRSymtabFile > readIRSymtab(MemoryBufferRef MBRef)
Reads a bitcode file, creating its irsymtab if necessary.
iterator_range< global_value_iterator > global_values()
Definition: Module.h:667
void wait()
Blocking wait for all the threads to complete and the queue to be empty.
Definition: ThreadPool.cpp:72
llvm::Error materializeMetadata()
Definition: Module.cpp:400
static IntegerType * getInt8Ty(LLVMContext &C)
Definition: Type.cpp:174
PointerType * getType() const
Global values are always pointers.
Definition: GlobalValue.h:273
std::string getThinLTOOutputFile(const std::string &Path, const std::string &OldPrefix, const std::string &NewPrefix)
Given the original Path to an output file, replace any path prefix matching OldPrefix with NewPrefix...
Definition: LTO.cpp:1040
void thinLTOInternalizeAndPromoteInIndex(ModuleSummaryIndex &Index, function_ref< bool(StringRef, GlobalValue::GUID)> isExported)
Update the linkages in the given Index to mark exported values as external and non-exported values as...
Definition: LTO.cpp:355
bool empty() const
empty - Check if the array is empty.
Definition: ArrayRef.h:144
std::error_code inconvertibleErrorCode()
The value returned by this function can be returned from convertToErrorCode for Error values where no...
Definition: Error.cpp:73
A discriminated union of two pointer types, with the discriminator in the low bit of the pointer...
Definition: PointerUnion.h:87
iterator_range< alias_iterator > aliases()
Definition: Module.h:606