xref: /llvm-project/llvm/lib/MC/MCContext.cpp (revision e7f02241ad4d38fc50b63ad589a024323e6bc3c6) 
1 //===- lib/MC/MCContext.cpp - Machine Code Context ------------------------===//
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 "llvm/MC/MCContext.h"
10 #include "llvm/ADT/SmallString.h"
11 #include "llvm/ADT/SmallVector.h"
12 #include "llvm/ADT/StringMap.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/ADT/Twine.h"
15 #include "llvm/BinaryFormat/COFF.h"
16 #include "llvm/BinaryFormat/ELF.h"
17 #include "llvm/BinaryFormat/Wasm.h"
18 #include "llvm/BinaryFormat/XCOFF.h"
19 #include "llvm/MC/MCAsmInfo.h"
20 #include "llvm/MC/MCCodeView.h"
21 #include "llvm/MC/MCDwarf.h"
22 #include "llvm/MC/MCExpr.h"
23 #include "llvm/MC/MCFragment.h"
24 #include "llvm/MC/MCInst.h"
25 #include "llvm/MC/MCLabel.h"
26 #include "llvm/MC/MCSectionCOFF.h"
27 #include "llvm/MC/MCSectionDXContainer.h"
28 #include "llvm/MC/MCSectionELF.h"
29 #include "llvm/MC/MCSectionGOFF.h"
30 #include "llvm/MC/MCSectionMachO.h"
31 #include "llvm/MC/MCSectionSPIRV.h"
32 #include "llvm/MC/MCSectionWasm.h"
33 #include "llvm/MC/MCSectionXCOFF.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSubtargetInfo.h"
36 #include "llvm/MC/MCSymbol.h"
37 #include "llvm/MC/MCSymbolCOFF.h"
38 #include "llvm/MC/MCSymbolELF.h"
39 #include "llvm/MC/MCSymbolGOFF.h"
40 #include "llvm/MC/MCSymbolMachO.h"
41 #include "llvm/MC/MCSymbolWasm.h"
42 #include "llvm/MC/MCSymbolXCOFF.h"
43 #include "llvm/MC/MCTargetOptions.h"
44 #include "llvm/MC/SectionKind.h"
45 #include "llvm/Support/Casting.h"
46 #include "llvm/Support/EndianStream.h"
47 #include "llvm/Support/ErrorHandling.h"
48 #include "llvm/Support/MemoryBuffer.h"
49 #include "llvm/Support/Path.h"
50 #include "llvm/Support/SMLoc.h"
51 #include "llvm/Support/SourceMgr.h"
52 #include "llvm/Support/raw_ostream.h"
53 #include <cassert>
54 #include <cstdlib>
55 #include <optional>
56 #include <tuple>
57 #include <utility>
58 
59 using namespace llvm;
60 
61 static void defaultDiagHandler(const SMDiagnostic &SMD, bool, const SourceMgr &,
62                                std::vector<const MDNode *> &) {
63   SMD.print(nullptr, errs());
64 }
65 
66 MCContext::MCContext(const Triple &TheTriple, const MCAsmInfo *mai,
67                      const MCRegisterInfo *mri, const MCSubtargetInfo *msti,
68                      const SourceMgr *mgr, MCTargetOptions const *TargetOpts,
69                      bool DoAutoReset, StringRef Swift5ReflSegmentName)
70     : Swift5ReflectionSegmentName(Swift5ReflSegmentName), TT(TheTriple),
71       SrcMgr(mgr), InlineSrcMgr(nullptr), DiagHandler(defaultDiagHandler),
72       MAI(mai), MRI(mri), MSTI(msti), Symbols(Allocator),
73       InlineAsmUsedLabelNames(Allocator),
74       CurrentDwarfLoc(0, 0, 0, DWARF2_FLAG_IS_STMT, 0, 0),
75       AutoReset(DoAutoReset), TargetOptions(TargetOpts) {
76   SaveTempLabels = TargetOptions && TargetOptions->MCSaveTempLabels;
77   SecureLogFile = TargetOptions ? TargetOptions->AsSecureLogFile : "";
78 
79   if (SrcMgr && SrcMgr->getNumBuffers())
80     MainFileName = std::string(SrcMgr->getMemoryBuffer(SrcMgr->getMainFileID())
81                                    ->getBufferIdentifier());
82 
83   switch (TheTriple.getObjectFormat()) {
84   case Triple::MachO:
85     Env = IsMachO;
86     break;
87   case Triple::COFF:
88     if (!TheTriple.isOSWindowsOrUEFI())
89       report_fatal_error(
90           "Cannot initialize MC for non-Windows COFF object files.");
91 
92     Env = IsCOFF;
93     break;
94   case Triple::ELF:
95     Env = IsELF;
96     break;
97   case Triple::Wasm:
98     Env = IsWasm;
99     break;
100   case Triple::XCOFF:
101     Env = IsXCOFF;
102     break;
103   case Triple::GOFF:
104     Env = IsGOFF;
105     break;
106   case Triple::DXContainer:
107     Env = IsDXContainer;
108     break;
109   case Triple::SPIRV:
110     Env = IsSPIRV;
111     break;
112   case Triple::UnknownObjectFormat:
113     report_fatal_error("Cannot initialize MC for unknown object file format.");
114     break;
115   }
116 }
117 
118 MCContext::~MCContext() {
119   if (AutoReset)
120     reset();
121 
122   // NOTE: The symbols are all allocated out of a bump pointer allocator,
123   // we don't need to free them here.
124 }
125 
126 void MCContext::initInlineSourceManager() {
127   if (!InlineSrcMgr)
128     InlineSrcMgr.reset(new SourceMgr());
129 }
130 
131 //===----------------------------------------------------------------------===//
132 // Module Lifetime Management
133 //===----------------------------------------------------------------------===//
134 
135 void MCContext::reset() {
136   SrcMgr = nullptr;
137   InlineSrcMgr.reset();
138   LocInfos.clear();
139   DiagHandler = defaultDiagHandler;
140 
141   // Call the destructors so the fragments are freed
142   COFFAllocator.DestroyAll();
143   DXCAllocator.DestroyAll();
144   ELFAllocator.DestroyAll();
145   GOFFAllocator.DestroyAll();
146   MachOAllocator.DestroyAll();
147   WasmAllocator.DestroyAll();
148   XCOFFAllocator.DestroyAll();
149   MCInstAllocator.DestroyAll();
150   SPIRVAllocator.DestroyAll();
151   WasmSignatureAllocator.DestroyAll();
152 
153   // ~CodeViewContext may destroy a MCFragment outside of sections and need to
154   // be reset before FragmentAllocator.
155   CVContext.reset();
156 
157   MCSubtargetAllocator.DestroyAll();
158   InlineAsmUsedLabelNames.clear();
159   Symbols.clear();
160   Allocator.Reset();
161   FragmentAllocator.Reset();
162   Instances.clear();
163   CompilationDir.clear();
164   MainFileName.clear();
165   MCDwarfLineTablesCUMap.clear();
166   SectionsForRanges.clear();
167   MCGenDwarfLabelEntries.clear();
168   DwarfDebugFlags = StringRef();
169   DwarfCompileUnitID = 0;
170   CurrentDwarfLoc = MCDwarfLoc(0, 0, 0, DWARF2_FLAG_IS_STMT, 0, 0);
171 
172   MachOUniquingMap.clear();
173   ELFUniquingMap.clear();
174   GOFFUniquingMap.clear();
175   COFFUniquingMap.clear();
176   WasmUniquingMap.clear();
177   XCOFFUniquingMap.clear();
178   DXCUniquingMap.clear();
179 
180   ELFEntrySizeMap.clear();
181   ELFSeenGenericMergeableSections.clear();
182 
183   DwarfLocSeen = false;
184   GenDwarfForAssembly = false;
185   GenDwarfFileNumber = 0;
186 
187   HadError = false;
188 }
189 
190 //===----------------------------------------------------------------------===//
191 // MCInst Management
192 //===----------------------------------------------------------------------===//
193 
194 MCInst *MCContext::createMCInst() {
195   return new (MCInstAllocator.Allocate()) MCInst;
196 }
197 
198 // Allocate the initial MCDataFragment for the begin symbol.
199 MCDataFragment *MCContext::allocInitialFragment(MCSection &Sec) {
200   assert(!Sec.curFragList()->Head);
201   auto *F = allocFragment<MCDataFragment>();
202   F->setParent(&Sec);
203   Sec.curFragList()->Head = F;
204   Sec.curFragList()->Tail = F;
205   return F;
206 }
207 
208 //===----------------------------------------------------------------------===//
209 // Symbol Manipulation
210 //===----------------------------------------------------------------------===//
211 
212 MCSymbol *MCContext::getOrCreateSymbol(const Twine &Name) {
213   SmallString<128> NameSV;
214   StringRef NameRef = Name.toStringRef(NameSV);
215 
216   assert(!NameRef.empty() && "Normal symbols cannot be unnamed!");
217 
218   MCSymbolTableEntry &Entry = getSymbolTableEntry(NameRef);
219   if (!Entry.second.Symbol) {
220     bool IsRenamable = NameRef.starts_with(MAI->getPrivateGlobalPrefix());
221     bool IsTemporary = IsRenamable && !SaveTempLabels;
222     if (!Entry.second.Used) {
223       Entry.second.Used = true;
224       Entry.second.Symbol = createSymbolImpl(&Entry, IsTemporary);
225     } else {
226       assert(IsRenamable && "cannot rename non-private symbol");
227       // Slow path: we need to rename a temp symbol from the user.
228       Entry.second.Symbol = createRenamableSymbol(NameRef, false, IsTemporary);
229     }
230   }
231 
232   return Entry.second.Symbol;
233 }
234 
235 MCSymbol *MCContext::getOrCreateFrameAllocSymbol(const Twine &FuncName,
236                                                  unsigned Idx) {
237   return getOrCreateSymbol(MAI->getPrivateGlobalPrefix() + FuncName +
238                            "$frame_escape_" + Twine(Idx));
239 }
240 
241 MCSymbol *MCContext::getOrCreateParentFrameOffsetSymbol(const Twine &FuncName) {
242   return getOrCreateSymbol(MAI->getPrivateGlobalPrefix() + FuncName +
243                            "$parent_frame_offset");
244 }
245 
246 MCSymbol *MCContext::getOrCreateLSDASymbol(const Twine &FuncName) {
247   return getOrCreateSymbol(MAI->getPrivateGlobalPrefix() + "__ehtable$" +
248                            FuncName);
249 }
250 
251 MCSymbolTableEntry &MCContext::getSymbolTableEntry(StringRef Name) {
252   return *Symbols.try_emplace(Name, MCSymbolTableValue{}).first;
253 }
254 
255 MCSymbol *MCContext::createSymbolImpl(const MCSymbolTableEntry *Name,
256                                       bool IsTemporary) {
257   static_assert(std::is_trivially_destructible<MCSymbolCOFF>(),
258                 "MCSymbol classes must be trivially destructible");
259   static_assert(std::is_trivially_destructible<MCSymbolELF>(),
260                 "MCSymbol classes must be trivially destructible");
261   static_assert(std::is_trivially_destructible<MCSymbolMachO>(),
262                 "MCSymbol classes must be trivially destructible");
263   static_assert(std::is_trivially_destructible<MCSymbolWasm>(),
264                 "MCSymbol classes must be trivially destructible");
265   static_assert(std::is_trivially_destructible<MCSymbolXCOFF>(),
266                 "MCSymbol classes must be trivially destructible");
267 
268   switch (getObjectFileType()) {
269   case MCContext::IsCOFF:
270     return new (Name, *this) MCSymbolCOFF(Name, IsTemporary);
271   case MCContext::IsELF:
272     return new (Name, *this) MCSymbolELF(Name, IsTemporary);
273   case MCContext::IsGOFF:
274     return new (Name, *this) MCSymbolGOFF(Name, IsTemporary);
275   case MCContext::IsMachO:
276     return new (Name, *this) MCSymbolMachO(Name, IsTemporary);
277   case MCContext::IsWasm:
278     return new (Name, *this) MCSymbolWasm(Name, IsTemporary);
279   case MCContext::IsXCOFF:
280     return createXCOFFSymbolImpl(Name, IsTemporary);
281   case MCContext::IsDXContainer:
282     break;
283   case MCContext::IsSPIRV:
284     return new (Name, *this)
285         MCSymbol(MCSymbol::SymbolKindUnset, Name, IsTemporary);
286   }
287   return new (Name, *this)
288       MCSymbol(MCSymbol::SymbolKindUnset, Name, IsTemporary);
289 }
290 
291 MCSymbol *MCContext::createRenamableSymbol(const Twine &Name,
292                                            bool AlwaysAddSuffix,
293                                            bool IsTemporary) {
294   SmallString<128> NewName;
295   Name.toVector(NewName);
296   size_t NameLen = NewName.size();
297 
298   MCSymbolTableEntry &NameEntry = getSymbolTableEntry(NewName.str());
299   MCSymbolTableEntry *EntryPtr = &NameEntry;
300   while (AlwaysAddSuffix || EntryPtr->second.Used) {
301     AlwaysAddSuffix = false;
302 
303     NewName.resize(NameLen);
304     raw_svector_ostream(NewName) << NameEntry.second.NextUniqueID++;
305     EntryPtr = &getSymbolTableEntry(NewName.str());
306   }
307 
308   EntryPtr->second.Used = true;
309   return createSymbolImpl(EntryPtr, IsTemporary);
310 }
311 
312 MCSymbol *MCContext::createTempSymbol(const Twine &Name, bool AlwaysAddSuffix) {
313   if (!UseNamesOnTempLabels)
314     return createSymbolImpl(nullptr, /*IsTemporary=*/true);
315   return createRenamableSymbol(MAI->getPrivateGlobalPrefix() + Name,
316                                AlwaysAddSuffix, /*IsTemporary=*/true);
317 }
318 
319 MCSymbol *MCContext::createNamedTempSymbol(const Twine &Name) {
320   return createRenamableSymbol(MAI->getPrivateGlobalPrefix() + Name, true,
321                                /*IsTemporary=*/!SaveTempLabels);
322 }
323 
324 MCSymbol *MCContext::createBlockSymbol(const Twine &Name, bool AlwaysEmit) {
325   if (AlwaysEmit)
326     return getOrCreateSymbol(MAI->getPrivateLabelPrefix() + Name);
327 
328   bool IsTemporary = !SaveTempLabels;
329   if (IsTemporary && !UseNamesOnTempLabels)
330     return createSymbolImpl(nullptr, IsTemporary);
331   return createRenamableSymbol(MAI->getPrivateLabelPrefix() + Name,
332                                /*AlwaysAddSuffix=*/false, IsTemporary);
333 }
334 
335 MCSymbol *MCContext::createLinkerPrivateTempSymbol() {
336   return createLinkerPrivateSymbol("tmp");
337 }
338 
339 MCSymbol *MCContext::createLinkerPrivateSymbol(const Twine &Name) {
340   return createRenamableSymbol(MAI->getLinkerPrivateGlobalPrefix() + Name,
341                                /*AlwaysAddSuffix=*/true,
342                                /*IsTemporary=*/false);
343 }
344 
345 MCSymbol *MCContext::createTempSymbol() { return createTempSymbol("tmp"); }
346 
347 MCSymbol *MCContext::createNamedTempSymbol() {
348   return createNamedTempSymbol("tmp");
349 }
350 
351 MCSymbol *MCContext::createLocalSymbol(StringRef Name) {
352   MCSymbolTableEntry &NameEntry = getSymbolTableEntry(Name);
353   return createSymbolImpl(&NameEntry, /*IsTemporary=*/false);
354 }
355 
356 unsigned MCContext::NextInstance(unsigned LocalLabelVal) {
357   MCLabel *&Label = Instances[LocalLabelVal];
358   if (!Label)
359     Label = new (*this) MCLabel(0);
360   return Label->incInstance();
361 }
362 
363 unsigned MCContext::GetInstance(unsigned LocalLabelVal) {
364   MCLabel *&Label = Instances[LocalLabelVal];
365   if (!Label)
366     Label = new (*this) MCLabel(0);
367   return Label->getInstance();
368 }
369 
370 MCSymbol *MCContext::getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
371                                                        unsigned Instance) {
372   MCSymbol *&Sym = LocalSymbols[std::make_pair(LocalLabelVal, Instance)];
373   if (!Sym)
374     Sym = createNamedTempSymbol();
375   return Sym;
376 }
377 
378 MCSymbol *MCContext::createDirectionalLocalSymbol(unsigned LocalLabelVal) {
379   unsigned Instance = NextInstance(LocalLabelVal);
380   return getOrCreateDirectionalLocalSymbol(LocalLabelVal, Instance);
381 }
382 
383 MCSymbol *MCContext::getDirectionalLocalSymbol(unsigned LocalLabelVal,
384                                                bool Before) {
385   unsigned Instance = GetInstance(LocalLabelVal);
386   if (!Before)
387     ++Instance;
388   return getOrCreateDirectionalLocalSymbol(LocalLabelVal, Instance);
389 }
390 
391 template <typename Symbol>
392 Symbol *MCContext::getOrCreateSectionSymbol(StringRef Section) {
393   Symbol *R;
394   auto &SymEntry = getSymbolTableEntry(Section);
395   MCSymbol *Sym = SymEntry.second.Symbol;
396   // A section symbol can not redefine regular symbols. There may be multiple
397   // sections with the same name, in which case the first such section wins.
398   if (Sym && Sym->isDefined() &&
399       (!Sym->isInSection() || Sym->getSection().getBeginSymbol() != Sym))
400     reportError(SMLoc(), "invalid symbol redefinition");
401   if (Sym && Sym->isUndefined()) {
402     R = cast<Symbol>(Sym);
403   } else {
404     SymEntry.second.Used = true;
405     R = new (&SymEntry, *this) Symbol(&SymEntry, /*isTemporary=*/false);
406     if (!Sym)
407       SymEntry.second.Symbol = R;
408   }
409   return R;
410 }
411 
412 MCSymbol *MCContext::lookupSymbol(const Twine &Name) const {
413   SmallString<128> NameSV;
414   StringRef NameRef = Name.toStringRef(NameSV);
415   return Symbols.lookup(NameRef).Symbol;
416 }
417 
418 void MCContext::setSymbolValue(MCStreamer &Streamer, const Twine &Sym,
419                                uint64_t Val) {
420   auto Symbol = getOrCreateSymbol(Sym);
421   Streamer.emitAssignment(Symbol, MCConstantExpr::create(Val, *this));
422 }
423 
424 void MCContext::registerInlineAsmLabel(MCSymbol *Sym) {
425   InlineAsmUsedLabelNames[Sym->getName()] = Sym;
426 }
427 
428 wasm::WasmSignature *MCContext::createWasmSignature() {
429   return new (WasmSignatureAllocator.Allocate()) wasm::WasmSignature;
430 }
431 
432 MCSymbolXCOFF *MCContext::createXCOFFSymbolImpl(const MCSymbolTableEntry *Name,
433                                                 bool IsTemporary) {
434   if (!Name)
435     return new (nullptr, *this) MCSymbolXCOFF(nullptr, IsTemporary);
436 
437   StringRef OriginalName = Name->first();
438   if (OriginalName.starts_with("._Renamed..") ||
439       OriginalName.starts_with("_Renamed.."))
440     reportError(SMLoc(), "invalid symbol name from source");
441 
442   if (MAI->isValidUnquotedName(OriginalName))
443     return new (Name, *this) MCSymbolXCOFF(Name, IsTemporary);
444 
445   // Now we have a name that contains invalid character(s) for XCOFF symbol.
446   // Let's replace with something valid, but save the original name so that
447   // we could still use the original name in the symbol table.
448   SmallString<128> InvalidName(OriginalName);
449 
450   // If it's an entry point symbol, we will keep the '.'
451   // in front for the convention purpose. Otherwise, add "_Renamed.."
452   // as prefix to signal this is an renamed symbol.
453   const bool IsEntryPoint = InvalidName.starts_with(".");
454   SmallString<128> ValidName =
455       StringRef(IsEntryPoint ? "._Renamed.." : "_Renamed..");
456 
457   // Append the hex values of '_' and invalid characters with "_Renamed..";
458   // at the same time replace invalid characters with '_'.
459   for (size_t I = 0; I < InvalidName.size(); ++I) {
460     if (!MAI->isAcceptableChar(InvalidName[I]) || InvalidName[I] == '_') {
461       raw_svector_ostream(ValidName).write_hex(InvalidName[I]);
462       InvalidName[I] = '_';
463     }
464   }
465 
466   // Skip entry point symbol's '.' as we already have a '.' in front of
467   // "_Renamed".
468   if (IsEntryPoint)
469     ValidName.append(InvalidName.substr(1, InvalidName.size() - 1));
470   else
471     ValidName.append(InvalidName);
472 
473   MCSymbolTableEntry &NameEntry = getSymbolTableEntry(ValidName.str());
474   assert(!NameEntry.second.Used && "This name is used somewhere else.");
475   NameEntry.second.Used = true;
476   // Have the MCSymbol object itself refer to the copy of the string
477   // that is embedded in the symbol table entry.
478   MCSymbolXCOFF *XSym =
479       new (&NameEntry, *this) MCSymbolXCOFF(&NameEntry, IsTemporary);
480   XSym->setSymbolTableName(MCSymbolXCOFF::getUnqualifiedName(OriginalName));
481   return XSym;
482 }
483 
484 //===----------------------------------------------------------------------===//
485 // Section Management
486 //===----------------------------------------------------------------------===//
487 
488 MCSectionMachO *MCContext::getMachOSection(StringRef Segment, StringRef Section,
489                                            unsigned TypeAndAttributes,
490                                            unsigned Reserved2, SectionKind Kind,
491                                            const char *BeginSymName) {
492   // We unique sections by their segment/section pair.  The returned section
493   // may not have the same flags as the requested section, if so this should be
494   // diagnosed by the client as an error.
495 
496   // Form the name to look up.
497   assert(Section.size() <= 16 && "section name is too long");
498   assert(!memchr(Section.data(), '\0', Section.size()) &&
499          "section name cannot contain NUL");
500 
501   // Do the lookup, if we have a hit, return it.
502   auto R = MachOUniquingMap.try_emplace((Segment + Twine(',') + Section).str());
503   if (!R.second)
504     return R.first->second;
505 
506   MCSymbol *Begin = nullptr;
507   if (BeginSymName)
508     Begin = createTempSymbol(BeginSymName, false);
509 
510   // Otherwise, return a new section.
511   StringRef Name = R.first->first();
512   auto *Ret = new (MachOAllocator.Allocate())
513       MCSectionMachO(Segment, Name.substr(Name.size() - Section.size()),
514                      TypeAndAttributes, Reserved2, Kind, Begin);
515   R.first->second = Ret;
516   allocInitialFragment(*Ret);
517   return Ret;
518 }
519 
520 MCSectionELF *MCContext::createELFSectionImpl(StringRef Section, unsigned Type,
521                                               unsigned Flags,
522                                               unsigned EntrySize,
523                                               const MCSymbolELF *Group,
524                                               bool Comdat, unsigned UniqueID,
525                                               const MCSymbolELF *LinkedToSym) {
526   auto *R = getOrCreateSectionSymbol<MCSymbolELF>(Section);
527   R->setBinding(ELF::STB_LOCAL);
528   R->setType(ELF::STT_SECTION);
529 
530   auto *Ret = new (ELFAllocator.Allocate()) MCSectionELF(
531       Section, Type, Flags, EntrySize, Group, Comdat, UniqueID, R, LinkedToSym);
532 
533   auto *F = allocInitialFragment(*Ret);
534   R->setFragment(F);
535   return Ret;
536 }
537 
538 MCSectionELF *
539 MCContext::createELFRelSection(const Twine &Name, unsigned Type, unsigned Flags,
540                                unsigned EntrySize, const MCSymbolELF *Group,
541                                const MCSectionELF *RelInfoSection) {
542   StringMap<bool>::iterator I;
543   bool Inserted;
544   std::tie(I, Inserted) = RelSecNames.insert(std::make_pair(Name.str(), true));
545 
546   return createELFSectionImpl(
547       I->getKey(), Type, Flags, EntrySize, Group, true, true,
548       cast<MCSymbolELF>(RelInfoSection->getBeginSymbol()));
549 }
550 
551 MCSectionELF *MCContext::getELFNamedSection(const Twine &Prefix,
552                                             const Twine &Suffix, unsigned Type,
553                                             unsigned Flags,
554                                             unsigned EntrySize) {
555   return getELFSection(Prefix + "." + Suffix, Type, Flags, EntrySize, Suffix,
556                        /*IsComdat=*/true);
557 }
558 
559 MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
560                                        unsigned Flags, unsigned EntrySize,
561                                        const Twine &Group, bool IsComdat,
562                                        unsigned UniqueID,
563                                        const MCSymbolELF *LinkedToSym) {
564   MCSymbolELF *GroupSym = nullptr;
565   if (!Group.isTriviallyEmpty() && !Group.str().empty())
566     GroupSym = cast<MCSymbolELF>(getOrCreateSymbol(Group));
567 
568   return getELFSection(Section, Type, Flags, EntrySize, GroupSym, IsComdat,
569                        UniqueID, LinkedToSym);
570 }
571 
572 MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
573                                        unsigned Flags, unsigned EntrySize,
574                                        const MCSymbolELF *GroupSym,
575                                        bool IsComdat, unsigned UniqueID,
576                                        const MCSymbolELF *LinkedToSym) {
577   StringRef Group = "";
578   if (GroupSym)
579     Group = GroupSym->getName();
580   assert(!(LinkedToSym && LinkedToSym->getName().empty()));
581 
582   // Sections are differentiated by the quadruple (section_name, group_name,
583   // unique_id, link_to_symbol_name). Sections sharing the same quadruple are
584   // combined into one section. As an optimization, non-unique sections without
585   // group or linked-to symbol have a shorter unique-ing key.
586   std::pair<StringMap<MCSectionELF *>::iterator, bool> EntryNewPair;
587   // Length of the section name, which are the first SectionLen bytes of the key
588   unsigned SectionLen;
589   if (GroupSym || LinkedToSym || UniqueID != MCSection::NonUniqueID) {
590     SmallString<128> Buffer;
591     Section.toVector(Buffer);
592     SectionLen = Buffer.size();
593     Buffer.push_back(0); // separator which cannot occur in the name
594     if (GroupSym)
595       Buffer.append(GroupSym->getName());
596     Buffer.push_back(0); // separator which cannot occur in the name
597     if (LinkedToSym)
598       Buffer.append(LinkedToSym->getName());
599     support::endian::write(Buffer, UniqueID, endianness::native);
600     StringRef UniqueMapKey = StringRef(Buffer);
601     EntryNewPair = ELFUniquingMap.insert(std::make_pair(UniqueMapKey, nullptr));
602   } else if (!Section.isSingleStringRef()) {
603     SmallString<128> Buffer;
604     StringRef UniqueMapKey = Section.toStringRef(Buffer);
605     SectionLen = UniqueMapKey.size();
606     EntryNewPair = ELFUniquingMap.insert(std::make_pair(UniqueMapKey, nullptr));
607   } else {
608     StringRef UniqueMapKey = Section.getSingleStringRef();
609     SectionLen = UniqueMapKey.size();
610     EntryNewPair = ELFUniquingMap.insert(std::make_pair(UniqueMapKey, nullptr));
611   }
612 
613   if (!EntryNewPair.second)
614     return EntryNewPair.first->second;
615 
616   StringRef CachedName = EntryNewPair.first->getKey().take_front(SectionLen);
617 
618   MCSectionELF *Result =
619       createELFSectionImpl(CachedName, Type, Flags, EntrySize, GroupSym,
620                            IsComdat, UniqueID, LinkedToSym);
621   EntryNewPair.first->second = Result;
622 
623   recordELFMergeableSectionInfo(Result->getName(), Result->getFlags(),
624                                 Result->getUniqueID(), Result->getEntrySize());
625 
626   return Result;
627 }
628 
629 MCSectionELF *MCContext::createELFGroupSection(const MCSymbolELF *Group,
630                                                bool IsComdat) {
631   return createELFSectionImpl(".group", ELF::SHT_GROUP, 0, 4, Group, IsComdat,
632                               MCSection::NonUniqueID, nullptr);
633 }
634 
635 void MCContext::recordELFMergeableSectionInfo(StringRef SectionName,
636                                               unsigned Flags, unsigned UniqueID,
637                                               unsigned EntrySize) {
638   bool IsMergeable = Flags & ELF::SHF_MERGE;
639   if (UniqueID == GenericSectionID) {
640     ELFSeenGenericMergeableSections.insert(SectionName);
641     // Minor performance optimization: avoid hash map lookup in
642     // isELFGenericMergeableSection, which will return true for SectionName.
643     IsMergeable = true;
644   }
645 
646   // For mergeable sections or non-mergeable sections with a generic mergeable
647   // section name we enter their Unique ID into the ELFEntrySizeMap so that
648   // compatible globals can be assigned to the same section.
649 
650   if (IsMergeable || isELFGenericMergeableSection(SectionName)) {
651     ELFEntrySizeMap.insert(std::make_pair(
652         std::make_tuple(SectionName, Flags, EntrySize), UniqueID));
653   }
654 }
655 
656 bool MCContext::isELFImplicitMergeableSectionNamePrefix(StringRef SectionName) {
657   return SectionName.starts_with(".rodata.str") ||
658          SectionName.starts_with(".rodata.cst");
659 }
660 
661 bool MCContext::isELFGenericMergeableSection(StringRef SectionName) {
662   return isELFImplicitMergeableSectionNamePrefix(SectionName) ||
663          ELFSeenGenericMergeableSections.count(SectionName);
664 }
665 
666 std::optional<unsigned>
667 MCContext::getELFUniqueIDForEntsize(StringRef SectionName, unsigned Flags,
668                                     unsigned EntrySize) {
669   auto I = ELFEntrySizeMap.find(std::make_tuple(SectionName, Flags, EntrySize));
670   return (I != ELFEntrySizeMap.end()) ? std::optional<unsigned>(I->second)
671                                       : std::nullopt;
672 }
673 
674 MCSectionGOFF *MCContext::getGOFFSection(StringRef Section, SectionKind Kind,
675                                          MCSection *Parent,
676                                          uint32_t Subsection) {
677   // Do the lookup. If we don't have a hit, return a new section.
678   auto IterBool =
679       GOFFUniquingMap.insert(std::make_pair(Section.str(), nullptr));
680   auto Iter = IterBool.first;
681   if (!IterBool.second)
682     return Iter->second;
683 
684   StringRef CachedName = Iter->first;
685   MCSectionGOFF *GOFFSection = new (GOFFAllocator.Allocate())
686       MCSectionGOFF(CachedName, Kind, Parent, Subsection);
687   Iter->second = GOFFSection;
688   allocInitialFragment(*GOFFSection);
689   return GOFFSection;
690 }
691 
692 MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
693                                          unsigned Characteristics,
694                                          StringRef COMDATSymName, int Selection,
695                                          unsigned UniqueID) {
696   MCSymbol *COMDATSymbol = nullptr;
697   if (!COMDATSymName.empty()) {
698     COMDATSymbol = getOrCreateSymbol(COMDATSymName);
699     assert(COMDATSymbol && "COMDATSymbol is null");
700     COMDATSymName = COMDATSymbol->getName();
701     // A non-associative COMDAT is considered to define the COMDAT symbol. Check
702     // the redefinition error.
703     if (Selection != COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE &&
704         COMDATSymbol->isDefined() &&
705         (!COMDATSymbol->isInSection() ||
706          cast<MCSectionCOFF>(COMDATSymbol->getSection()).getCOMDATSymbol() !=
707              COMDATSymbol))
708       reportError(SMLoc(), "invalid symbol redefinition");
709   }
710 
711   // Do the lookup, if we have a hit, return it.
712   COFFSectionKey T{Section, COMDATSymName, Selection, UniqueID};
713   auto IterBool = COFFUniquingMap.insert(std::make_pair(T, nullptr));
714   auto Iter = IterBool.first;
715   if (!IterBool.second)
716     return Iter->second;
717 
718   StringRef CachedName = Iter->first.SectionName;
719   MCSymbol *Begin = getOrCreateSectionSymbol<MCSymbolCOFF>(Section);
720   MCSectionCOFF *Result = new (COFFAllocator.Allocate()) MCSectionCOFF(
721       CachedName, Characteristics, COMDATSymbol, Selection, Begin);
722   Iter->second = Result;
723   auto *F = allocInitialFragment(*Result);
724   Begin->setFragment(F);
725   return Result;
726 }
727 
728 MCSectionCOFF *MCContext::getCOFFSection(StringRef Section,
729                                          unsigned Characteristics) {
730   return getCOFFSection(Section, Characteristics, "", 0, GenericSectionID);
731 }
732 
733 MCSectionCOFF *MCContext::getAssociativeCOFFSection(MCSectionCOFF *Sec,
734                                                     const MCSymbol *KeySym,
735                                                     unsigned UniqueID) {
736   // Return the normal section if we don't have to be associative or unique.
737   if (!KeySym && UniqueID == GenericSectionID)
738     return Sec;
739 
740   // If we have a key symbol, make an associative section with the same name and
741   // kind as the normal section.
742   unsigned Characteristics = Sec->getCharacteristics();
743   if (KeySym) {
744     Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
745     return getCOFFSection(Sec->getName(), Characteristics, KeySym->getName(),
746                           COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE, UniqueID);
747   }
748 
749   return getCOFFSection(Sec->getName(), Characteristics, "", 0, UniqueID);
750 }
751 
752 MCSectionWasm *MCContext::getWasmSection(const Twine &Section, SectionKind K,
753                                          unsigned Flags, const Twine &Group,
754                                          unsigned UniqueID) {
755   MCSymbolWasm *GroupSym = nullptr;
756   if (!Group.isTriviallyEmpty() && !Group.str().empty()) {
757     GroupSym = cast<MCSymbolWasm>(getOrCreateSymbol(Group));
758     GroupSym->setComdat(true);
759     if (K.isMetadata() && !GroupSym->getType().has_value()) {
760       // Comdat group symbol associated with a custom section is a section
761       // symbol (not a data symbol).
762       GroupSym->setType(wasm::WASM_SYMBOL_TYPE_SECTION);
763     }
764   }
765 
766   return getWasmSection(Section, K, Flags, GroupSym, UniqueID);
767 }
768 
769 MCSectionWasm *MCContext::getWasmSection(const Twine &Section, SectionKind Kind,
770                                          unsigned Flags,
771                                          const MCSymbolWasm *GroupSym,
772                                          unsigned UniqueID) {
773   StringRef Group = "";
774   if (GroupSym)
775     Group = GroupSym->getName();
776   // Do the lookup, if we have a hit, return it.
777   auto IterBool = WasmUniquingMap.insert(
778       std::make_pair(WasmSectionKey{Section.str(), Group, UniqueID}, nullptr));
779   auto &Entry = *IterBool.first;
780   if (!IterBool.second)
781     return Entry.second;
782 
783   StringRef CachedName = Entry.first.SectionName;
784 
785   MCSymbol *Begin = createRenamableSymbol(CachedName, true, false);
786   // Begin always has a different name than CachedName... see #48596.
787   getSymbolTableEntry(Begin->getName()).second.Symbol = Begin;
788   cast<MCSymbolWasm>(Begin)->setType(wasm::WASM_SYMBOL_TYPE_SECTION);
789 
790   MCSectionWasm *Result = new (WasmAllocator.Allocate())
791       MCSectionWasm(CachedName, Kind, Flags, GroupSym, UniqueID, Begin);
792   Entry.second = Result;
793 
794   auto *F = allocInitialFragment(*Result);
795   Begin->setFragment(F);
796   return Result;
797 }
798 
799 bool MCContext::hasXCOFFSection(StringRef Section,
800                                 XCOFF::CsectProperties CsectProp) const {
801   return XCOFFUniquingMap.count(
802              XCOFFSectionKey(Section.str(), CsectProp.MappingClass)) != 0;
803 }
804 
805 MCSectionXCOFF *MCContext::getXCOFFSection(
806     StringRef Section, SectionKind Kind,
807     std::optional<XCOFF::CsectProperties> CsectProp, bool MultiSymbolsAllowed,
808     std::optional<XCOFF::DwarfSectionSubtypeFlags> DwarfSectionSubtypeFlags) {
809   bool IsDwarfSec = DwarfSectionSubtypeFlags.has_value();
810   assert((IsDwarfSec != CsectProp.has_value()) && "Invalid XCOFF section!");
811 
812   // Do the lookup. If we have a hit, return it.
813   auto IterBool = XCOFFUniquingMap.insert(std::make_pair(
814       IsDwarfSec ? XCOFFSectionKey(Section.str(), *DwarfSectionSubtypeFlags)
815                  : XCOFFSectionKey(Section.str(), CsectProp->MappingClass),
816       nullptr));
817   auto &Entry = *IterBool.first;
818   if (!IterBool.second) {
819     MCSectionXCOFF *ExistedEntry = Entry.second;
820     if (ExistedEntry->isMultiSymbolsAllowed() != MultiSymbolsAllowed)
821       report_fatal_error("section's multiply symbols policy does not match");
822 
823     return ExistedEntry;
824   }
825 
826   // Otherwise, return a new section.
827   StringRef CachedName = Entry.first.SectionName;
828   MCSymbolXCOFF *QualName = nullptr;
829   // Debug section don't have storage class attribute.
830   if (IsDwarfSec)
831     QualName = cast<MCSymbolXCOFF>(getOrCreateSymbol(CachedName));
832   else
833     QualName = cast<MCSymbolXCOFF>(getOrCreateSymbol(
834         CachedName + "[" +
835         XCOFF::getMappingClassString(CsectProp->MappingClass) + "]"));
836 
837   // QualName->getUnqualifiedName() and CachedName are the same except when
838   // CachedName contains invalid character(s) such as '$' for an XCOFF symbol.
839   MCSectionXCOFF *Result = nullptr;
840   if (IsDwarfSec)
841     Result = new (XCOFFAllocator.Allocate()) MCSectionXCOFF(
842         QualName->getUnqualifiedName(), Kind, QualName,
843         *DwarfSectionSubtypeFlags, QualName, CachedName, MultiSymbolsAllowed);
844   else
845     Result = new (XCOFFAllocator.Allocate())
846         MCSectionXCOFF(QualName->getUnqualifiedName(), CsectProp->MappingClass,
847                        CsectProp->Type, Kind, QualName, nullptr, CachedName,
848                        MultiSymbolsAllowed);
849 
850   Entry.second = Result;
851 
852   auto *F = allocInitialFragment(*Result);
853 
854   // We might miss calculating the symbols difference as absolute value before
855   // adding fixups when symbol_A without the fragment set is the csect itself
856   // and symbol_B is in it.
857   // TODO: Currently we only set the fragment for XMC_PR csects and DWARF
858   // sections because we don't have other cases that hit this problem yet.
859   if (IsDwarfSec || CsectProp->MappingClass == XCOFF::XMC_PR)
860     QualName->setFragment(F);
861 
862   return Result;
863 }
864 
865 MCSectionSPIRV *MCContext::getSPIRVSection() {
866   MCSectionSPIRV *Result = new (SPIRVAllocator.Allocate()) MCSectionSPIRV();
867 
868   allocInitialFragment(*Result);
869   return Result;
870 }
871 
872 MCSectionDXContainer *MCContext::getDXContainerSection(StringRef Section,
873                                                        SectionKind K) {
874   // Do the lookup, if we have a hit, return it.
875   auto ItInsertedPair = DXCUniquingMap.try_emplace(Section);
876   if (!ItInsertedPair.second)
877     return ItInsertedPair.first->second;
878 
879   auto MapIt = ItInsertedPair.first;
880   // Grab the name from the StringMap. Since the Section is going to keep a
881   // copy of this StringRef we need to make sure the underlying string stays
882   // alive as long as we need it.
883   StringRef Name = MapIt->first();
884   MapIt->second =
885       new (DXCAllocator.Allocate()) MCSectionDXContainer(Name, K, nullptr);
886 
887   // The first fragment will store the header
888   allocInitialFragment(*MapIt->second);
889   return MapIt->second;
890 }
891 
892 MCSubtargetInfo &MCContext::getSubtargetCopy(const MCSubtargetInfo &STI) {
893   return *new (MCSubtargetAllocator.Allocate()) MCSubtargetInfo(STI);
894 }
895 
896 void MCContext::addDebugPrefixMapEntry(const std::string &From,
897                                        const std::string &To) {
898   DebugPrefixMap.emplace_back(From, To);
899 }
900 
901 void MCContext::remapDebugPath(SmallVectorImpl<char> &Path) {
902   for (const auto &[From, To] : llvm::reverse(DebugPrefixMap))
903     if (llvm::sys::path::replace_path_prefix(Path, From, To))
904       break;
905 }
906 
907 void MCContext::RemapDebugPaths() {
908   const auto &DebugPrefixMap = this->DebugPrefixMap;
909   if (DebugPrefixMap.empty())
910     return;
911 
912   // Remap compilation directory.
913   remapDebugPath(CompilationDir);
914 
915   // Remap MCDwarfDirs and RootFile.Name in all compilation units.
916   SmallString<256> P;
917   for (auto &CUIDTablePair : MCDwarfLineTablesCUMap) {
918     for (auto &Dir : CUIDTablePair.second.getMCDwarfDirs()) {
919       P = Dir;
920       remapDebugPath(P);
921       Dir = std::string(P);
922     }
923 
924     // Used by DW_TAG_compile_unit's DT_AT_name and DW_TAG_label's
925     // DW_AT_decl_file for DWARF v5 generated for assembly source.
926     P = CUIDTablePair.second.getRootFile().Name;
927     remapDebugPath(P);
928     CUIDTablePair.second.getRootFile().Name = std::string(P);
929   }
930 }
931 
932 //===----------------------------------------------------------------------===//
933 // Dwarf Management
934 //===----------------------------------------------------------------------===//
935 
936 EmitDwarfUnwindType MCContext::emitDwarfUnwindInfo() const {
937   if (!TargetOptions)
938     return EmitDwarfUnwindType::Default;
939   return TargetOptions->EmitDwarfUnwind;
940 }
941 
942 bool MCContext::emitCompactUnwindNonCanonical() const {
943   if (TargetOptions)
944     return TargetOptions->EmitCompactUnwindNonCanonical;
945   return false;
946 }
947 
948 void MCContext::setGenDwarfRootFile(StringRef InputFileName, StringRef Buffer) {
949   // MCDwarf needs the root file as well as the compilation directory.
950   // If we find a '.file 0' directive that will supersede these values.
951   std::optional<MD5::MD5Result> Cksum;
952   if (getDwarfVersion() >= 5) {
953     MD5 Hash;
954     MD5::MD5Result Sum;
955     Hash.update(Buffer);
956     Hash.final(Sum);
957     Cksum = Sum;
958   }
959   // Canonicalize the root filename. It cannot be empty, and should not
960   // repeat the compilation dir.
961   // The MCContext ctor initializes MainFileName to the name associated with
962   // the SrcMgr's main file ID, which might be the same as InputFileName (and
963   // possibly include directory components).
964   // Or, MainFileName might have been overridden by a -main-file-name option,
965   // which is supposed to be just a base filename with no directory component.
966   // So, if the InputFileName and MainFileName are not equal, assume
967   // MainFileName is a substitute basename and replace the last component.
968   SmallString<1024> FileNameBuf = InputFileName;
969   if (FileNameBuf.empty() || FileNameBuf == "-")
970     FileNameBuf = "<stdin>";
971   if (!getMainFileName().empty() && FileNameBuf != getMainFileName()) {
972     llvm::sys::path::remove_filename(FileNameBuf);
973     llvm::sys::path::append(FileNameBuf, getMainFileName());
974   }
975   StringRef FileName = FileNameBuf;
976   if (FileName.consume_front(getCompilationDir()))
977     if (llvm::sys::path::is_separator(FileName.front()))
978       FileName = FileName.drop_front();
979   assert(!FileName.empty());
980   setMCLineTableRootFile(
981       /*CUID=*/0, getCompilationDir(), FileName, Cksum, std::nullopt);
982 }
983 
984 /// getDwarfFile - takes a file name and number to place in the dwarf file and
985 /// directory tables.  If the file number has already been allocated it is an
986 /// error and zero is returned and the client reports the error, else the
987 /// allocated file number is returned.  The file numbers may be in any order.
988 Expected<unsigned>
989 MCContext::getDwarfFile(StringRef Directory, StringRef FileName,
990                         unsigned FileNumber,
991                         std::optional<MD5::MD5Result> Checksum,
992                         std::optional<StringRef> Source, unsigned CUID) {
993   MCDwarfLineTable &Table = MCDwarfLineTablesCUMap[CUID];
994   return Table.tryGetFile(Directory, FileName, Checksum, Source, DwarfVersion,
995                           FileNumber);
996 }
997 
998 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
999 /// currently is assigned and false otherwise.
1000 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
1001   const MCDwarfLineTable &LineTable = getMCDwarfLineTable(CUID);
1002   if (FileNumber == 0)
1003     return getDwarfVersion() >= 5;
1004   if (FileNumber >= LineTable.getMCDwarfFiles().size())
1005     return false;
1006 
1007   return !LineTable.getMCDwarfFiles()[FileNumber].Name.empty();
1008 }
1009 
1010 /// Remove empty sections from SectionsForRanges, to avoid generating
1011 /// useless debug info for them.
1012 void MCContext::finalizeDwarfSections(MCStreamer &MCOS) {
1013   SectionsForRanges.remove_if(
1014       [&](MCSection *Sec) { return !MCOS.mayHaveInstructions(*Sec); });
1015 }
1016 
1017 CodeViewContext &MCContext::getCVContext() {
1018   if (!CVContext)
1019     CVContext.reset(new CodeViewContext(this));
1020   return *CVContext;
1021 }
1022 
1023 //===----------------------------------------------------------------------===//
1024 // Error Reporting
1025 //===----------------------------------------------------------------------===//
1026 
1027 void MCContext::diagnose(const SMDiagnostic &SMD) {
1028   assert(DiagHandler && "MCContext::DiagHandler is not set");
1029   bool UseInlineSrcMgr = false;
1030   const SourceMgr *SMP = nullptr;
1031   if (SrcMgr) {
1032     SMP = SrcMgr;
1033   } else if (InlineSrcMgr) {
1034     SMP = InlineSrcMgr.get();
1035     UseInlineSrcMgr = true;
1036   } else
1037     llvm_unreachable("Either SourceMgr should be available");
1038   DiagHandler(SMD, UseInlineSrcMgr, *SMP, LocInfos);
1039 }
1040 
1041 void MCContext::reportCommon(
1042     SMLoc Loc,
1043     std::function<void(SMDiagnostic &, const SourceMgr *)> GetMessage) {
1044   // * MCContext::SrcMgr is null when the MC layer emits machine code for input
1045   //   other than assembly file, say, for .c/.cpp/.ll/.bc.
1046   // * MCContext::InlineSrcMgr is null when the inline asm is not used.
1047   // * A default SourceMgr is needed for diagnosing when both MCContext::SrcMgr
1048   //   and MCContext::InlineSrcMgr are null.
1049   SourceMgr SM;
1050   const SourceMgr *SMP = &SM;
1051   bool UseInlineSrcMgr = false;
1052 
1053   // FIXME: Simplify these by combining InlineSrcMgr & SrcMgr.
1054   //        For MC-only execution, only SrcMgr is used;
1055   //        For non MC-only execution, InlineSrcMgr is only ctor'd if there is
1056   //        inline asm in the IR.
1057   if (Loc.isValid()) {
1058     if (SrcMgr) {
1059       SMP = SrcMgr;
1060     } else if (InlineSrcMgr) {
1061       SMP = InlineSrcMgr.get();
1062       UseInlineSrcMgr = true;
1063     } else
1064       llvm_unreachable("Either SourceMgr should be available");
1065   }
1066 
1067   SMDiagnostic D;
1068   GetMessage(D, SMP);
1069   DiagHandler(D, UseInlineSrcMgr, *SMP, LocInfos);
1070 }
1071 
1072 void MCContext::reportError(SMLoc Loc, const Twine &Msg) {
1073   HadError = true;
1074   reportCommon(Loc, [&](SMDiagnostic &D, const SourceMgr *SMP) {
1075     D = SMP->GetMessage(Loc, SourceMgr::DK_Error, Msg);
1076   });
1077 }
1078 
1079 void MCContext::reportWarning(SMLoc Loc, const Twine &Msg) {
1080   if (TargetOptions && TargetOptions->MCNoWarn)
1081     return;
1082   if (TargetOptions && TargetOptions->MCFatalWarnings) {
1083     reportError(Loc, Msg);
1084   } else {
1085     reportCommon(Loc, [&](SMDiagnostic &D, const SourceMgr *SMP) {
1086       D = SMP->GetMessage(Loc, SourceMgr::DK_Warning, Msg);
1087     });
1088   }
1089 }
1090