1 //===- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp ----------------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file contains support for writing Microsoft CodeView debug info.
11 //===----------------------------------------------------------------------===//
13 #include "CodeViewDebug.h"
14 #include "DwarfExpression.h"
15 #include "llvm/ADT/APSInt.h"
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/DenseSet.h"
19 #include "llvm/ADT/MapVector.h"
20 #include "llvm/ADT/None.h"
21 #include "llvm/ADT/Optional.h"
22 #include "llvm/ADT/STLExtras.h"
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/ADT/SmallVector.h"
25 #include "llvm/ADT/StringRef.h"
26 #include "llvm/ADT/TinyPtrVector.h"
27 #include "llvm/ADT/Triple.h"
28 #include "llvm/ADT/Twine.h"
29 #include "llvm/BinaryFormat/COFF.h"
30 #include "llvm/BinaryFormat/Dwarf.h"
31 #include "llvm/CodeGen/AsmPrinter.h"
32 #include "llvm/CodeGen/LexicalScopes.h"
33 #include "llvm/CodeGen/MachineFrameInfo.h"
34 #include "llvm/CodeGen/MachineFunction.h"
35 #include "llvm/CodeGen/MachineInstr.h"
36 #include "llvm/CodeGen/MachineModuleInfo.h"
37 #include "llvm/CodeGen/MachineOperand.h"
38 #include "llvm/CodeGen/TargetFrameLowering.h"
39 #include "llvm/CodeGen/TargetRegisterInfo.h"
40 #include "llvm/CodeGen/TargetSubtargetInfo.h"
41 #include "llvm/Config/llvm-config.h"
42 #include "llvm/DebugInfo/CodeView/CVTypeVisitor.h"
43 #include "llvm/DebugInfo/CodeView/CodeView.h"
44 #include "llvm/DebugInfo/CodeView/CodeViewRecordIO.h"
45 #include "llvm/DebugInfo/CodeView/ContinuationRecordBuilder.h"
46 #include "llvm/DebugInfo/CodeView/DebugInlineeLinesSubsection.h"
47 #include "llvm/DebugInfo/CodeView/EnumTables.h"
48 #include "llvm/DebugInfo/CodeView/Line.h"
49 #include "llvm/DebugInfo/CodeView/SymbolRecord.h"
50 #include "llvm/DebugInfo/CodeView/TypeDumpVisitor.h"
51 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
52 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
53 #include "llvm/DebugInfo/CodeView/TypeTableCollection.h"
54 #include "llvm/DebugInfo/CodeView/TypeVisitorCallbackPipeline.h"
55 #include "llvm/IR/Constants.h"
56 #include "llvm/IR/DataLayout.h"
57 #include "llvm/IR/DebugInfoMetadata.h"
58 #include "llvm/IR/DebugLoc.h"
59 #include "llvm/IR/Function.h"
60 #include "llvm/IR/GlobalValue.h"
61 #include "llvm/IR/GlobalVariable.h"
62 #include "llvm/IR/Metadata.h"
63 #include "llvm/IR/Module.h"
64 #include "llvm/MC/MCAsmInfo.h"
65 #include "llvm/MC/MCContext.h"
66 #include "llvm/MC/MCSectionCOFF.h"
67 #include "llvm/MC/MCStreamer.h"
68 #include "llvm/MC/MCSymbol.h"
69 #include "llvm/Support/BinaryByteStream.h"
70 #include "llvm/Support/BinaryStreamReader.h"
71 #include "llvm/Support/BinaryStreamWriter.h"
72 #include "llvm/Support/Casting.h"
73 #include "llvm/Support/CommandLine.h"
74 #include "llvm/Support/Compiler.h"
75 #include "llvm/Support/Endian.h"
76 #include "llvm/Support/Error.h"
77 #include "llvm/Support/ErrorHandling.h"
78 #include "llvm/Support/FormatVariadic.h"
79 #include "llvm/Support/Path.h"
80 #include "llvm/Support/SMLoc.h"
81 #include "llvm/Support/ScopedPrinter.h"
82 #include "llvm/Target/TargetLoweringObjectFile.h"
83 #include "llvm/Target/TargetMachine.h"
96 using namespace llvm::codeview;
99 class CVMCAdapter : public CodeViewRecordStreamer {
101 CVMCAdapter(MCStreamer &OS) : OS(&OS) {}
103 void EmitBytes(StringRef Data) { OS->EmitBytes(Data); }
105 void EmitIntValue(uint64_t Value, unsigned Size) {
106 OS->EmitIntValueInHex(Value, Size);
109 void EmitBinaryData(StringRef Data) { OS->EmitBinaryData(Data); }
111 void AddComment(const Twine &T) { OS->AddComment(T); }
114 MCStreamer *OS = nullptr;
118 static CPUType mapArchToCVCPUType(Triple::ArchType Type) {
120 case Triple::ArchType::x86:
121 return CPUType::Pentium3;
122 case Triple::ArchType::x86_64:
124 case Triple::ArchType::thumb:
125 return CPUType::Thumb;
126 case Triple::ArchType::aarch64:
127 return CPUType::ARM64;
129 report_fatal_error("target architecture doesn't map to a CodeView CPUType");
133 CodeViewDebug::CodeViewDebug(AsmPrinter *AP)
134 : DebugHandlerBase(AP), OS(*Asm->OutStreamer), TypeTable(Allocator) {
135 // If module doesn't have named metadata anchors or COFF debug section
136 // is not available, skip any debug info related stuff.
137 if (!MMI->getModule()->getNamedMetadata("llvm.dbg.cu") ||
138 !AP->getObjFileLowering().getCOFFDebugSymbolsSection()) {
140 MMI->setDebugInfoAvailability(false);
143 // Tell MMI that we have debug info.
144 MMI->setDebugInfoAvailability(true);
147 mapArchToCVCPUType(Triple(MMI->getModule()->getTargetTriple()).getArch());
149 collectGlobalVariableInfo();
151 // Check if we should emit type record hashes.
152 ConstantInt *GH = mdconst::extract_or_null<ConstantInt>(
153 MMI->getModule()->getModuleFlag("CodeViewGHash"));
154 EmitDebugGlobalHashes = GH && !GH->isZero();
157 StringRef CodeViewDebug::getFullFilepath(const DIFile *File) {
158 std::string &Filepath = FileToFilepathMap[File];
159 if (!Filepath.empty())
162 StringRef Dir = File->getDirectory(), Filename = File->getFilename();
164 // If this is a Unix-style path, just use it as is. Don't try to canonicalize
165 // it textually because one of the path components could be a symlink.
166 if (Dir.startswith("/") || Filename.startswith("/")) {
167 if (llvm::sys::path::is_absolute(Filename, llvm::sys::path::Style::posix))
170 if (Dir.back() != '/')
172 Filepath += Filename;
176 // Clang emits directory and relative filename info into the IR, but CodeView
177 // operates on full paths. We could change Clang to emit full paths too, but
178 // that would increase the IR size and probably not needed for other users.
179 // For now, just concatenate and canonicalize the path here.
180 if (Filename.find(':') == 1)
183 Filepath = (Dir + "\\" + Filename).str();
185 // Canonicalize the path. We have to do it textually because we may no longer
186 // have access the file in the filesystem.
187 // First, replace all slashes with backslashes.
188 std::replace(Filepath.begin(), Filepath.end(), '/', '\\');
190 // Remove all "\.\" with "\".
192 while ((Cursor = Filepath.find("\\.\\", Cursor)) != std::string::npos)
193 Filepath.erase(Cursor, 2);
195 // Replace all "\XXX\..\" with "\". Don't try too hard though as the original
196 // path should be well-formatted, e.g. start with a drive letter, etc.
198 while ((Cursor = Filepath.find("\\..\\", Cursor)) != std::string::npos) {
199 // Something's wrong if the path starts with "\..\", abort.
203 size_t PrevSlash = Filepath.rfind('\\', Cursor - 1);
204 if (PrevSlash == std::string::npos)
205 // Something's wrong, abort.
208 Filepath.erase(PrevSlash, Cursor + 3 - PrevSlash);
209 // The next ".." might be following the one we've just erased.
213 // Remove all duplicate backslashes.
215 while ((Cursor = Filepath.find("\\\\", Cursor)) != std::string::npos)
216 Filepath.erase(Cursor, 1);
221 unsigned CodeViewDebug::maybeRecordFile(const DIFile *F) {
222 StringRef FullPath = getFullFilepath(F);
223 unsigned NextId = FileIdMap.size() + 1;
224 auto Insertion = FileIdMap.insert(std::make_pair(FullPath, NextId));
225 if (Insertion.second) {
226 // We have to compute the full filepath and emit a .cv_file directive.
227 ArrayRef<uint8_t> ChecksumAsBytes;
228 FileChecksumKind CSKind = FileChecksumKind::None;
229 if (F->getChecksum()) {
230 std::string Checksum = fromHex(F->getChecksum()->Value);
231 void *CKMem = OS.getContext().allocate(Checksum.size(), 1);
232 memcpy(CKMem, Checksum.data(), Checksum.size());
233 ChecksumAsBytes = ArrayRef<uint8_t>(
234 reinterpret_cast<const uint8_t *>(CKMem), Checksum.size());
235 switch (F->getChecksum()->Kind) {
236 case DIFile::CSK_MD5: CSKind = FileChecksumKind::MD5; break;
237 case DIFile::CSK_SHA1: CSKind = FileChecksumKind::SHA1; break;
240 bool Success = OS.EmitCVFileDirective(NextId, FullPath, ChecksumAsBytes,
241 static_cast<unsigned>(CSKind));
243 assert(Success && ".cv_file directive failed");
245 return Insertion.first->second;
248 CodeViewDebug::InlineSite &
249 CodeViewDebug::getInlineSite(const DILocation *InlinedAt,
250 const DISubprogram *Inlinee) {
251 auto SiteInsertion = CurFn->InlineSites.insert({InlinedAt, InlineSite()});
252 InlineSite *Site = &SiteInsertion.first->second;
253 if (SiteInsertion.second) {
254 unsigned ParentFuncId = CurFn->FuncId;
255 if (const DILocation *OuterIA = InlinedAt->getInlinedAt())
257 getInlineSite(OuterIA, InlinedAt->getScope()->getSubprogram())
260 Site->SiteFuncId = NextFuncId++;
261 OS.EmitCVInlineSiteIdDirective(
262 Site->SiteFuncId, ParentFuncId, maybeRecordFile(InlinedAt->getFile()),
263 InlinedAt->getLine(), InlinedAt->getColumn(), SMLoc());
264 Site->Inlinee = Inlinee;
265 InlinedSubprograms.insert(Inlinee);
266 getFuncIdForSubprogram(Inlinee);
271 static StringRef getPrettyScopeName(const DIScope *Scope) {
272 StringRef ScopeName = Scope->getName();
273 if (!ScopeName.empty())
276 switch (Scope->getTag()) {
277 case dwarf::DW_TAG_enumeration_type:
278 case dwarf::DW_TAG_class_type:
279 case dwarf::DW_TAG_structure_type:
280 case dwarf::DW_TAG_union_type:
281 return "<unnamed-tag>";
282 case dwarf::DW_TAG_namespace:
283 return "`anonymous namespace'";
289 static const DISubprogram *getQualifiedNameComponents(
290 const DIScope *Scope, SmallVectorImpl<StringRef> &QualifiedNameComponents) {
291 const DISubprogram *ClosestSubprogram = nullptr;
292 while (Scope != nullptr) {
293 if (ClosestSubprogram == nullptr)
294 ClosestSubprogram = dyn_cast<DISubprogram>(Scope);
295 StringRef ScopeName = getPrettyScopeName(Scope);
296 if (!ScopeName.empty())
297 QualifiedNameComponents.push_back(ScopeName);
298 Scope = Scope->getScope();
300 return ClosestSubprogram;
303 static std::string getQualifiedName(ArrayRef<StringRef> QualifiedNameComponents,
304 StringRef TypeName) {
305 std::string FullyQualifiedName;
306 for (StringRef QualifiedNameComponent :
307 llvm::reverse(QualifiedNameComponents)) {
308 FullyQualifiedName.append(QualifiedNameComponent);
309 FullyQualifiedName.append("::");
311 FullyQualifiedName.append(TypeName);
312 return FullyQualifiedName;
315 static std::string getFullyQualifiedName(const DIScope *Scope, StringRef Name) {
316 SmallVector<StringRef, 5> QualifiedNameComponents;
317 getQualifiedNameComponents(Scope, QualifiedNameComponents);
318 return getQualifiedName(QualifiedNameComponents, Name);
321 struct CodeViewDebug::TypeLoweringScope {
322 TypeLoweringScope(CodeViewDebug &CVD) : CVD(CVD) { ++CVD.TypeEmissionLevel; }
323 ~TypeLoweringScope() {
324 // Don't decrement TypeEmissionLevel until after emitting deferred types, so
325 // inner TypeLoweringScopes don't attempt to emit deferred types.
326 if (CVD.TypeEmissionLevel == 1)
327 CVD.emitDeferredCompleteTypes();
328 --CVD.TypeEmissionLevel;
333 static std::string getFullyQualifiedName(const DIScope *Ty) {
334 const DIScope *Scope = Ty->getScope();
335 return getFullyQualifiedName(Scope, getPrettyScopeName(Ty));
338 TypeIndex CodeViewDebug::getScopeIndex(const DIScope *Scope) {
339 // No scope means global scope and that uses the zero index.
340 if (!Scope || isa<DIFile>(Scope))
343 assert(!isa<DIType>(Scope) && "shouldn't make a namespace scope for a type");
345 // Check if we've already translated this scope.
346 auto I = TypeIndices.find({Scope, nullptr});
347 if (I != TypeIndices.end())
350 // Build the fully qualified name of the scope.
351 std::string ScopeName = getFullyQualifiedName(Scope);
352 StringIdRecord SID(TypeIndex(), ScopeName);
353 auto TI = TypeTable.writeLeafType(SID);
354 return recordTypeIndexForDINode(Scope, TI);
357 TypeIndex CodeViewDebug::getFuncIdForSubprogram(const DISubprogram *SP) {
360 // Check if we've already translated this subprogram.
361 auto I = TypeIndices.find({SP, nullptr});
362 if (I != TypeIndices.end())
365 // The display name includes function template arguments. Drop them to match
367 StringRef DisplayName = SP->getName().split('<').first;
369 const DIScope *Scope = SP->getScope();
371 if (const auto *Class = dyn_cast_or_null<DICompositeType>(Scope)) {
372 // If the scope is a DICompositeType, then this must be a method. Member
373 // function types take some special handling, and require access to the
375 TypeIndex ClassType = getTypeIndex(Class);
376 MemberFuncIdRecord MFuncId(ClassType, getMemberFunctionType(SP, Class),
378 TI = TypeTable.writeLeafType(MFuncId);
380 // Otherwise, this must be a free function.
381 TypeIndex ParentScope = getScopeIndex(Scope);
382 FuncIdRecord FuncId(ParentScope, getTypeIndex(SP->getType()), DisplayName);
383 TI = TypeTable.writeLeafType(FuncId);
386 return recordTypeIndexForDINode(SP, TI);
389 static bool isNonTrivial(const DICompositeType *DCTy) {
390 return ((DCTy->getFlags() & DINode::FlagNonTrivial) == DINode::FlagNonTrivial);
393 static FunctionOptions
394 getFunctionOptions(const DISubroutineType *Ty,
395 const DICompositeType *ClassTy = nullptr,
396 StringRef SPName = StringRef("")) {
397 FunctionOptions FO = FunctionOptions::None;
398 const DIType *ReturnTy = nullptr;
399 if (auto TypeArray = Ty->getTypeArray()) {
400 if (TypeArray.size())
401 ReturnTy = TypeArray[0];
404 if (auto *ReturnDCTy = dyn_cast_or_null<DICompositeType>(ReturnTy)) {
405 if (isNonTrivial(ReturnDCTy))
406 FO |= FunctionOptions::CxxReturnUdt;
409 // DISubroutineType is unnamed. Use DISubprogram's i.e. SPName in comparison.
410 if (ClassTy && isNonTrivial(ClassTy) && SPName == ClassTy->getName()) {
411 FO |= FunctionOptions::Constructor;
413 // TODO: put the FunctionOptions::ConstructorWithVirtualBases flag.
419 TypeIndex CodeViewDebug::getMemberFunctionType(const DISubprogram *SP,
420 const DICompositeType *Class) {
421 // Always use the method declaration as the key for the function type. The
422 // method declaration contains the this adjustment.
423 if (SP->getDeclaration())
424 SP = SP->getDeclaration();
425 assert(!SP->getDeclaration() && "should use declaration as key");
427 // Key the MemberFunctionRecord into the map as {SP, Class}. It won't collide
428 // with the MemberFuncIdRecord, which is keyed in as {SP, nullptr}.
429 auto I = TypeIndices.find({SP, Class});
430 if (I != TypeIndices.end())
433 // Make sure complete type info for the class is emitted *after* the member
434 // function type, as the complete class type is likely to reference this
435 // member function type.
436 TypeLoweringScope S(*this);
437 const bool IsStaticMethod = (SP->getFlags() & DINode::FlagStaticMember) != 0;
439 FunctionOptions FO = getFunctionOptions(SP->getType(), Class, SP->getName());
440 TypeIndex TI = lowerTypeMemberFunction(
441 SP->getType(), Class, SP->getThisAdjustment(), IsStaticMethod, FO);
442 return recordTypeIndexForDINode(SP, TI, Class);
445 TypeIndex CodeViewDebug::recordTypeIndexForDINode(const DINode *Node,
447 const DIType *ClassTy) {
448 auto InsertResult = TypeIndices.insert({{Node, ClassTy}, TI});
450 assert(InsertResult.second && "DINode was already assigned a type index");
454 unsigned CodeViewDebug::getPointerSizeInBytes() {
455 return MMI->getModule()->getDataLayout().getPointerSizeInBits() / 8;
458 void CodeViewDebug::recordLocalVariable(LocalVariable &&Var,
459 const LexicalScope *LS) {
460 if (const DILocation *InlinedAt = LS->getInlinedAt()) {
461 // This variable was inlined. Associate it with the InlineSite.
462 const DISubprogram *Inlinee = Var.DIVar->getScope()->getSubprogram();
463 InlineSite &Site = getInlineSite(InlinedAt, Inlinee);
464 Site.InlinedLocals.emplace_back(Var);
466 // This variable goes into the corresponding lexical scope.
467 ScopeVariables[LS].emplace_back(Var);
471 static void addLocIfNotPresent(SmallVectorImpl<const DILocation *> &Locs,
472 const DILocation *Loc) {
473 auto B = Locs.begin(), E = Locs.end();
474 if (std::find(B, E, Loc) == E)
478 void CodeViewDebug::maybeRecordLocation(const DebugLoc &DL,
479 const MachineFunction *MF) {
480 // Skip this instruction if it has the same location as the previous one.
481 if (!DL || DL == PrevInstLoc)
484 const DIScope *Scope = DL.get()->getScope();
488 // Skip this line if it is longer than the maximum we can record.
489 LineInfo LI(DL.getLine(), DL.getLine(), /*IsStatement=*/true);
490 if (LI.getStartLine() != DL.getLine() || LI.isAlwaysStepInto() ||
491 LI.isNeverStepInto())
494 ColumnInfo CI(DL.getCol(), /*EndColumn=*/0);
495 if (CI.getStartColumn() != DL.getCol())
498 if (!CurFn->HaveLineInfo)
499 CurFn->HaveLineInfo = true;
501 if (PrevInstLoc.get() && PrevInstLoc->getFile() == DL->getFile())
502 FileId = CurFn->LastFileId;
504 FileId = CurFn->LastFileId = maybeRecordFile(DL->getFile());
507 unsigned FuncId = CurFn->FuncId;
508 if (const DILocation *SiteLoc = DL->getInlinedAt()) {
509 const DILocation *Loc = DL.get();
511 // If this location was actually inlined from somewhere else, give it the ID
512 // of the inline call site.
514 getInlineSite(SiteLoc, Loc->getScope()->getSubprogram()).SiteFuncId;
516 // Ensure we have links in the tree of inline call sites.
517 bool FirstLoc = true;
518 while ((SiteLoc = Loc->getInlinedAt())) {
520 getInlineSite(SiteLoc, Loc->getScope()->getSubprogram());
522 addLocIfNotPresent(Site.ChildSites, Loc);
526 addLocIfNotPresent(CurFn->ChildSites, Loc);
529 OS.EmitCVLocDirective(FuncId, FileId, DL.getLine(), DL.getCol(),
530 /*PrologueEnd=*/false, /*IsStmt=*/false,
531 DL->getFilename(), SMLoc());
534 void CodeViewDebug::emitCodeViewMagicVersion() {
535 OS.EmitValueToAlignment(4);
536 OS.AddComment("Debug section magic");
537 OS.EmitIntValue(COFF::DEBUG_SECTION_MAGIC, 4);
540 void CodeViewDebug::endModule() {
541 if (!Asm || !MMI->hasDebugInfo())
544 assert(Asm != nullptr);
546 // The COFF .debug$S section consists of several subsections, each starting
547 // with a 4-byte control code (e.g. 0xF1, 0xF2, etc) and then a 4-byte length
548 // of the payload followed by the payload itself. The subsections are 4-byte
551 // Use the generic .debug$S section, and make a subsection for all the inlined
553 switchToDebugSectionForSymbol(nullptr);
555 MCSymbol *CompilerInfo = beginCVSubsection(DebugSubsectionKind::Symbols);
556 emitCompilerInformation();
557 endCVSubsection(CompilerInfo);
559 emitInlineeLinesSubsection();
561 // Emit per-function debug information.
562 for (auto &P : FnDebugInfo)
563 if (!P.first->isDeclarationForLinker())
564 emitDebugInfoForFunction(P.first, *P.second);
566 // Emit global variable debug information.
567 setCurrentSubprogram(nullptr);
568 emitDebugInfoForGlobals();
570 // Emit retained types.
571 emitDebugInfoForRetainedTypes();
573 // Switch back to the generic .debug$S section after potentially processing
574 // comdat symbol sections.
575 switchToDebugSectionForSymbol(nullptr);
577 // Emit UDT records for any types used by global variables.
578 if (!GlobalUDTs.empty()) {
579 MCSymbol *SymbolsEnd = beginCVSubsection(DebugSubsectionKind::Symbols);
580 emitDebugInfoForUDTs(GlobalUDTs);
581 endCVSubsection(SymbolsEnd);
584 // This subsection holds a file index to offset in string table table.
585 OS.AddComment("File index to string table offset subsection");
586 OS.EmitCVFileChecksumsDirective();
588 // This subsection holds the string table.
589 OS.AddComment("String table");
590 OS.EmitCVStringTableDirective();
592 // Emit S_BUILDINFO, which points to LF_BUILDINFO. Put this in its own symbol
593 // subsection in the generic .debug$S section at the end. There is no
594 // particular reason for this ordering other than to match MSVC.
597 // Emit type information and hashes last, so that any types we translate while
598 // emitting function info are included.
599 emitTypeInformation();
601 if (EmitDebugGlobalHashes)
602 emitTypeGlobalHashes();
608 emitNullTerminatedSymbolName(MCStreamer &OS, StringRef S,
609 unsigned MaxFixedRecordLength = 0xF00) {
610 // The maximum CV record length is 0xFF00. Most of the strings we emit appear
611 // after a fixed length portion of the record. The fixed length portion should
612 // always be less than 0xF00 (3840) bytes, so truncate the string so that the
613 // overall record size is less than the maximum allowed.
614 SmallString<32> NullTerminatedString(
615 S.take_front(MaxRecordLength - MaxFixedRecordLength - 1));
616 NullTerminatedString.push_back('\0');
617 OS.EmitBytes(NullTerminatedString);
620 static StringRef getTypeLeafName(TypeLeafKind TypeKind) {
621 for (const EnumEntry<TypeLeafKind> &EE : getTypeLeafNames())
622 if (EE.Value == TypeKind)
627 void CodeViewDebug::emitTypeInformation() {
628 if (TypeTable.empty())
631 // Start the .debug$T or .debug$P section with 0x4.
632 OS.SwitchSection(Asm->getObjFileLowering().getCOFFDebugTypesSection());
633 emitCodeViewMagicVersion();
635 SmallString<8> CommentPrefix;
636 if (OS.isVerboseAsm()) {
637 CommentPrefix += '\t';
638 CommentPrefix += Asm->MAI->getCommentString();
639 CommentPrefix += ' ';
642 TypeTableCollection Table(TypeTable.records());
643 SmallString<512> CommentBlock;
644 raw_svector_ostream CommentOS(CommentBlock);
645 std::unique_ptr<ScopedPrinter> SP;
646 std::unique_ptr<TypeDumpVisitor> TDV;
647 TypeVisitorCallbackPipeline Pipeline;
649 if (OS.isVerboseAsm()) {
650 // To construct block comment describing the type record for readability.
651 SP = llvm::make_unique<ScopedPrinter>(CommentOS);
652 SP->setPrefix(CommentPrefix);
653 TDV = llvm::make_unique<TypeDumpVisitor>(Table, SP.get(), false);
654 Pipeline.addCallbackToPipeline(*TDV);
657 // To emit type record using Codeview MCStreamer adapter
658 CVMCAdapter CVMCOS(OS);
659 TypeRecordMapping typeMapping(CVMCOS);
660 Pipeline.addCallbackToPipeline(typeMapping);
662 Optional<TypeIndex> B = Table.getFirst();
664 // This will fail if the record data is invalid.
665 CVType Record = Table.getType(*B);
667 CommentBlock.clear();
669 auto RecordLen = Record.length();
670 auto RecordKind = Record.kind();
671 if (OS.isVerboseAsm())
672 CVMCOS.AddComment("Record length");
673 CVMCOS.EmitIntValue(RecordLen - 2, 2);
674 if (OS.isVerboseAsm())
675 CVMCOS.AddComment("Record kind: " + getTypeLeafName(RecordKind));
676 CVMCOS.EmitIntValue(RecordKind, sizeof(RecordKind));
678 Error E = codeview::visitTypeRecord(Record, *B, Pipeline);
681 logAllUnhandledErrors(std::move(E), errs(), "error: ");
682 llvm_unreachable("produced malformed type record");
685 if (OS.isVerboseAsm()) {
686 // emitRawComment will insert its own tab and comment string before
687 // the first line, so strip off our first one. It also prints its own
690 CommentOS.str().drop_front(CommentPrefix.size() - 1).rtrim());
692 B = Table.getNext(*B);
696 void CodeViewDebug::emitTypeGlobalHashes() {
697 if (TypeTable.empty())
700 // Start the .debug$H section with the version and hash algorithm, currently
701 // hardcoded to version 0, SHA1.
702 OS.SwitchSection(Asm->getObjFileLowering().getCOFFGlobalTypeHashesSection());
704 OS.EmitValueToAlignment(4);
705 OS.AddComment("Magic");
706 OS.EmitIntValue(COFF::DEBUG_HASHES_SECTION_MAGIC, 4);
707 OS.AddComment("Section Version");
708 OS.EmitIntValue(0, 2);
709 OS.AddComment("Hash Algorithm");
710 OS.EmitIntValue(uint16_t(GlobalTypeHashAlg::SHA1_8), 2);
712 TypeIndex TI(TypeIndex::FirstNonSimpleIndex);
713 for (const auto &GHR : TypeTable.hashes()) {
714 if (OS.isVerboseAsm()) {
715 // Emit an EOL-comment describing which TypeIndex this hash corresponds
716 // to, as well as the stringified SHA1 hash.
717 SmallString<32> Comment;
718 raw_svector_ostream CommentOS(Comment);
719 CommentOS << formatv("{0:X+} [{1}]", TI.getIndex(), GHR);
720 OS.AddComment(Comment);
723 assert(GHR.Hash.size() == 8);
724 StringRef S(reinterpret_cast<const char *>(GHR.Hash.data()),
726 OS.EmitBinaryData(S);
730 static SourceLanguage MapDWLangToCVLang(unsigned DWLang) {
732 case dwarf::DW_LANG_C:
733 case dwarf::DW_LANG_C89:
734 case dwarf::DW_LANG_C99:
735 case dwarf::DW_LANG_C11:
736 case dwarf::DW_LANG_ObjC:
737 return SourceLanguage::C;
738 case dwarf::DW_LANG_C_plus_plus:
739 case dwarf::DW_LANG_C_plus_plus_03:
740 case dwarf::DW_LANG_C_plus_plus_11:
741 case dwarf::DW_LANG_C_plus_plus_14:
742 return SourceLanguage::Cpp;
743 case dwarf::DW_LANG_Fortran77:
744 case dwarf::DW_LANG_Fortran90:
745 case dwarf::DW_LANG_Fortran03:
746 case dwarf::DW_LANG_Fortran08:
747 return SourceLanguage::Fortran;
748 case dwarf::DW_LANG_Pascal83:
749 return SourceLanguage::Pascal;
750 case dwarf::DW_LANG_Cobol74:
751 case dwarf::DW_LANG_Cobol85:
752 return SourceLanguage::Cobol;
753 case dwarf::DW_LANG_Java:
754 return SourceLanguage::Java;
755 case dwarf::DW_LANG_D:
756 return SourceLanguage::D;
757 case dwarf::DW_LANG_Swift:
758 return SourceLanguage::Swift;
760 // There's no CodeView representation for this language, and CV doesn't
761 // have an "unknown" option for the language field, so we'll use MASM,
762 // as it's very low level.
763 return SourceLanguage::Masm;
771 } // end anonymous namespace
773 // Takes a StringRef like "clang 4.0.0.0 (other nonsense 123)" and parses out
774 // the version number.
775 static Version parseVersion(StringRef Name) {
778 for (const char C : Name) {
781 V.Part[N] += C - '0';
782 } else if (C == '.') {
792 void CodeViewDebug::emitCompilerInformation() {
793 MCSymbol *CompilerEnd = beginSymbolRecord(SymbolKind::S_COMPILE3);
796 NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu");
797 const MDNode *Node = *CUs->operands().begin();
798 const auto *CU = cast<DICompileUnit>(Node);
800 // The low byte of the flags indicates the source language.
801 Flags = MapDWLangToCVLang(CU->getSourceLanguage());
802 // TODO: Figure out which other flags need to be set.
804 OS.AddComment("Flags and language");
805 OS.EmitIntValue(Flags, 4);
807 OS.AddComment("CPUType");
808 OS.EmitIntValue(static_cast<uint64_t>(TheCPU), 2);
810 StringRef CompilerVersion = CU->getProducer();
811 Version FrontVer = parseVersion(CompilerVersion);
812 OS.AddComment("Frontend version");
813 for (int N = 0; N < 4; ++N)
814 OS.EmitIntValue(FrontVer.Part[N], 2);
816 // Some Microsoft tools, like Binscope, expect a backend version number of at
817 // least 8.something, so we'll coerce the LLVM version into a form that
818 // guarantees it'll be big enough without really lying about the version.
819 int Major = 1000 * LLVM_VERSION_MAJOR +
820 10 * LLVM_VERSION_MINOR +
822 // Clamp it for builds that use unusually large version numbers.
823 Major = std::min<int>(Major, std::numeric_limits<uint16_t>::max());
824 Version BackVer = {{ Major, 0, 0, 0 }};
825 OS.AddComment("Backend version");
826 for (int N = 0; N < 4; ++N)
827 OS.EmitIntValue(BackVer.Part[N], 2);
829 OS.AddComment("Null-terminated compiler version string");
830 emitNullTerminatedSymbolName(OS, CompilerVersion);
832 endSymbolRecord(CompilerEnd);
835 static TypeIndex getStringIdTypeIdx(GlobalTypeTableBuilder &TypeTable,
837 StringIdRecord SIR(TypeIndex(0x0), S);
838 return TypeTable.writeLeafType(SIR);
841 void CodeViewDebug::emitBuildInfo() {
842 // First, make LF_BUILDINFO. It's a sequence of strings with various bits of
843 // build info. The known prefix is:
844 // - Absolute path of current directory
846 // - Main source file path, relative to CWD or absolute
847 // - Type server PDB file
848 // - Canonical compiler command line
849 // If frontend and backend compilation are separated (think llc or LTO), it's
850 // not clear if the compiler path should refer to the executable for the
851 // frontend or the backend. Leave it blank for now.
852 TypeIndex BuildInfoArgs[BuildInfoRecord::MaxArgs] = {};
853 NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu");
854 const MDNode *Node = *CUs->operands().begin(); // FIXME: Multiple CUs.
855 const auto *CU = cast<DICompileUnit>(Node);
856 const DIFile *MainSourceFile = CU->getFile();
857 BuildInfoArgs[BuildInfoRecord::CurrentDirectory] =
858 getStringIdTypeIdx(TypeTable, MainSourceFile->getDirectory());
859 BuildInfoArgs[BuildInfoRecord::SourceFile] =
860 getStringIdTypeIdx(TypeTable, MainSourceFile->getFilename());
861 // FIXME: Path to compiler and command line. PDB is intentionally blank unless
862 // we implement /Zi type servers.
863 BuildInfoRecord BIR(BuildInfoArgs);
864 TypeIndex BuildInfoIndex = TypeTable.writeLeafType(BIR);
866 // Make a new .debug$S subsection for the S_BUILDINFO record, which points
867 // from the module symbols into the type stream.
868 MCSymbol *BISubsecEnd = beginCVSubsection(DebugSubsectionKind::Symbols);
869 MCSymbol *BIEnd = beginSymbolRecord(SymbolKind::S_BUILDINFO);
870 OS.AddComment("LF_BUILDINFO index");
871 OS.EmitIntValue(BuildInfoIndex.getIndex(), 4);
872 endSymbolRecord(BIEnd);
873 endCVSubsection(BISubsecEnd);
876 void CodeViewDebug::emitInlineeLinesSubsection() {
877 if (InlinedSubprograms.empty())
880 OS.AddComment("Inlinee lines subsection");
881 MCSymbol *InlineEnd = beginCVSubsection(DebugSubsectionKind::InlineeLines);
883 // We emit the checksum info for files. This is used by debuggers to
884 // determine if a pdb matches the source before loading it. Visual Studio,
885 // for instance, will display a warning that the breakpoints are not valid if
886 // the pdb does not match the source.
887 OS.AddComment("Inlinee lines signature");
888 OS.EmitIntValue(unsigned(InlineeLinesSignature::Normal), 4);
890 for (const DISubprogram *SP : InlinedSubprograms) {
891 assert(TypeIndices.count({SP, nullptr}));
892 TypeIndex InlineeIdx = TypeIndices[{SP, nullptr}];
895 unsigned FileId = maybeRecordFile(SP->getFile());
896 OS.AddComment("Inlined function " + SP->getName() + " starts at " +
897 SP->getFilename() + Twine(':') + Twine(SP->getLine()));
899 OS.AddComment("Type index of inlined function");
900 OS.EmitIntValue(InlineeIdx.getIndex(), 4);
901 OS.AddComment("Offset into filechecksum table");
902 OS.EmitCVFileChecksumOffsetDirective(FileId);
903 OS.AddComment("Starting line number");
904 OS.EmitIntValue(SP->getLine(), 4);
907 endCVSubsection(InlineEnd);
910 void CodeViewDebug::emitInlinedCallSite(const FunctionInfo &FI,
911 const DILocation *InlinedAt,
912 const InlineSite &Site) {
913 assert(TypeIndices.count({Site.Inlinee, nullptr}));
914 TypeIndex InlineeIdx = TypeIndices[{Site.Inlinee, nullptr}];
917 MCSymbol *InlineEnd = beginSymbolRecord(SymbolKind::S_INLINESITE);
919 OS.AddComment("PtrParent");
920 OS.EmitIntValue(0, 4);
921 OS.AddComment("PtrEnd");
922 OS.EmitIntValue(0, 4);
923 OS.AddComment("Inlinee type index");
924 OS.EmitIntValue(InlineeIdx.getIndex(), 4);
926 unsigned FileId = maybeRecordFile(Site.Inlinee->getFile());
927 unsigned StartLineNum = Site.Inlinee->getLine();
929 OS.EmitCVInlineLinetableDirective(Site.SiteFuncId, FileId, StartLineNum,
932 endSymbolRecord(InlineEnd);
934 emitLocalVariableList(FI, Site.InlinedLocals);
936 // Recurse on child inlined call sites before closing the scope.
937 for (const DILocation *ChildSite : Site.ChildSites) {
938 auto I = FI.InlineSites.find(ChildSite);
939 assert(I != FI.InlineSites.end() &&
940 "child site not in function inline site map");
941 emitInlinedCallSite(FI, ChildSite, I->second);
945 emitEndSymbolRecord(SymbolKind::S_INLINESITE_END);
948 void CodeViewDebug::switchToDebugSectionForSymbol(const MCSymbol *GVSym) {
949 // If we have a symbol, it may be in a section that is COMDAT. If so, find the
950 // comdat key. A section may be comdat because of -ffunction-sections or
951 // because it is comdat in the IR.
952 MCSectionCOFF *GVSec =
953 GVSym ? dyn_cast<MCSectionCOFF>(&GVSym->getSection()) : nullptr;
954 const MCSymbol *KeySym = GVSec ? GVSec->getCOMDATSymbol() : nullptr;
956 MCSectionCOFF *DebugSec = cast<MCSectionCOFF>(
957 Asm->getObjFileLowering().getCOFFDebugSymbolsSection());
958 DebugSec = OS.getContext().getAssociativeCOFFSection(DebugSec, KeySym);
960 OS.SwitchSection(DebugSec);
962 // Emit the magic version number if this is the first time we've switched to
964 if (ComdatDebugSections.insert(DebugSec).second)
965 emitCodeViewMagicVersion();
968 // Emit an S_THUNK32/S_END symbol pair for a thunk routine.
969 // The only supported thunk ordinal is currently the standard type.
970 void CodeViewDebug::emitDebugInfoForThunk(const Function *GV,
972 const MCSymbol *Fn) {
973 std::string FuncName = GlobalValue::dropLLVMManglingEscape(GV->getName());
974 const ThunkOrdinal ordinal = ThunkOrdinal::Standard; // Only supported kind.
976 OS.AddComment("Symbol subsection for " + Twine(FuncName));
977 MCSymbol *SymbolsEnd = beginCVSubsection(DebugSubsectionKind::Symbols);
980 MCSymbol *ThunkRecordEnd = beginSymbolRecord(SymbolKind::S_THUNK32);
981 OS.AddComment("PtrParent");
982 OS.EmitIntValue(0, 4);
983 OS.AddComment("PtrEnd");
984 OS.EmitIntValue(0, 4);
985 OS.AddComment("PtrNext");
986 OS.EmitIntValue(0, 4);
987 OS.AddComment("Thunk section relative address");
988 OS.EmitCOFFSecRel32(Fn, /*Offset=*/0);
989 OS.AddComment("Thunk section index");
990 OS.EmitCOFFSectionIndex(Fn);
991 OS.AddComment("Code size");
992 OS.emitAbsoluteSymbolDiff(FI.End, Fn, 2);
993 OS.AddComment("Ordinal");
994 OS.EmitIntValue(unsigned(ordinal), 1);
995 OS.AddComment("Function name");
996 emitNullTerminatedSymbolName(OS, FuncName);
997 // Additional fields specific to the thunk ordinal would go here.
998 endSymbolRecord(ThunkRecordEnd);
1000 // Local variables/inlined routines are purposely omitted here. The point of
1001 // marking this as a thunk is so Visual Studio will NOT stop in this routine.
1003 // Emit S_PROC_ID_END
1004 emitEndSymbolRecord(SymbolKind::S_PROC_ID_END);
1006 endCVSubsection(SymbolsEnd);
1009 void CodeViewDebug::emitDebugInfoForFunction(const Function *GV,
1011 // For each function there is a separate subsection which holds the PC to
1013 const MCSymbol *Fn = Asm->getSymbol(GV);
1016 // Switch to the to a comdat section, if appropriate.
1017 switchToDebugSectionForSymbol(Fn);
1019 std::string FuncName;
1020 auto *SP = GV->getSubprogram();
1022 setCurrentSubprogram(SP);
1024 if (SP->isThunk()) {
1025 emitDebugInfoForThunk(GV, FI, Fn);
1029 // If we have a display name, build the fully qualified name by walking the
1031 if (!SP->getName().empty())
1032 FuncName = getFullyQualifiedName(SP->getScope(), SP->getName());
1034 // If our DISubprogram name is empty, use the mangled name.
1035 if (FuncName.empty())
1036 FuncName = GlobalValue::dropLLVMManglingEscape(GV->getName());
1038 // Emit FPO data, but only on 32-bit x86. No other platforms use it.
1039 if (Triple(MMI->getModule()->getTargetTriple()).getArch() == Triple::x86)
1040 OS.EmitCVFPOData(Fn);
1042 // Emit a symbol subsection, required by VS2012+ to find function boundaries.
1043 OS.AddComment("Symbol subsection for " + Twine(FuncName));
1044 MCSymbol *SymbolsEnd = beginCVSubsection(DebugSubsectionKind::Symbols);
1046 SymbolKind ProcKind = GV->hasLocalLinkage() ? SymbolKind::S_LPROC32_ID
1047 : SymbolKind::S_GPROC32_ID;
1048 MCSymbol *ProcRecordEnd = beginSymbolRecord(ProcKind);
1050 // These fields are filled in by tools like CVPACK which run after the fact.
1051 OS.AddComment("PtrParent");
1052 OS.EmitIntValue(0, 4);
1053 OS.AddComment("PtrEnd");
1054 OS.EmitIntValue(0, 4);
1055 OS.AddComment("PtrNext");
1056 OS.EmitIntValue(0, 4);
1057 // This is the important bit that tells the debugger where the function
1058 // code is located and what's its size:
1059 OS.AddComment("Code size");
1060 OS.emitAbsoluteSymbolDiff(FI.End, Fn, 4);
1061 OS.AddComment("Offset after prologue");
1062 OS.EmitIntValue(0, 4);
1063 OS.AddComment("Offset before epilogue");
1064 OS.EmitIntValue(0, 4);
1065 OS.AddComment("Function type index");
1066 OS.EmitIntValue(getFuncIdForSubprogram(GV->getSubprogram()).getIndex(), 4);
1067 OS.AddComment("Function section relative address");
1068 OS.EmitCOFFSecRel32(Fn, /*Offset=*/0);
1069 OS.AddComment("Function section index");
1070 OS.EmitCOFFSectionIndex(Fn);
1071 OS.AddComment("Flags");
1072 OS.EmitIntValue(0, 1);
1073 // Emit the function display name as a null-terminated string.
1074 OS.AddComment("Function name");
1075 // Truncate the name so we won't overflow the record length field.
1076 emitNullTerminatedSymbolName(OS, FuncName);
1077 endSymbolRecord(ProcRecordEnd);
1079 MCSymbol *FrameProcEnd = beginSymbolRecord(SymbolKind::S_FRAMEPROC);
1080 // Subtract out the CSR size since MSVC excludes that and we include it.
1081 OS.AddComment("FrameSize");
1082 OS.EmitIntValue(FI.FrameSize - FI.CSRSize, 4);
1083 OS.AddComment("Padding");
1084 OS.EmitIntValue(0, 4);
1085 OS.AddComment("Offset of padding");
1086 OS.EmitIntValue(0, 4);
1087 OS.AddComment("Bytes of callee saved registers");
1088 OS.EmitIntValue(FI.CSRSize, 4);
1089 OS.AddComment("Exception handler offset");
1090 OS.EmitIntValue(0, 4);
1091 OS.AddComment("Exception handler section");
1092 OS.EmitIntValue(0, 2);
1093 OS.AddComment("Flags (defines frame register)");
1094 OS.EmitIntValue(uint32_t(FI.FrameProcOpts), 4);
1095 endSymbolRecord(FrameProcEnd);
1097 emitLocalVariableList(FI, FI.Locals);
1098 emitGlobalVariableList(FI.Globals);
1099 emitLexicalBlockList(FI.ChildBlocks, FI);
1101 // Emit inlined call site information. Only emit functions inlined directly
1102 // into the parent function. We'll emit the other sites recursively as part
1103 // of their parent inline site.
1104 for (const DILocation *InlinedAt : FI.ChildSites) {
1105 auto I = FI.InlineSites.find(InlinedAt);
1106 assert(I != FI.InlineSites.end() &&
1107 "child site not in function inline site map");
1108 emitInlinedCallSite(FI, InlinedAt, I->second);
1111 for (auto Annot : FI.Annotations) {
1112 MCSymbol *Label = Annot.first;
1113 MDTuple *Strs = cast<MDTuple>(Annot.second);
1114 MCSymbol *AnnotEnd = beginSymbolRecord(SymbolKind::S_ANNOTATION);
1115 OS.EmitCOFFSecRel32(Label, /*Offset=*/0);
1116 // FIXME: Make sure we don't overflow the max record size.
1117 OS.EmitCOFFSectionIndex(Label);
1118 OS.EmitIntValue(Strs->getNumOperands(), 2);
1119 for (Metadata *MD : Strs->operands()) {
1120 // MDStrings are null terminated, so we can do EmitBytes and get the
1121 // nice .asciz directive.
1122 StringRef Str = cast<MDString>(MD)->getString();
1123 assert(Str.data()[Str.size()] == '\0' && "non-nullterminated MDString");
1124 OS.EmitBytes(StringRef(Str.data(), Str.size() + 1));
1126 endSymbolRecord(AnnotEnd);
1129 for (auto HeapAllocSite : FI.HeapAllocSites) {
1130 MCSymbol *BeginLabel = std::get<0>(HeapAllocSite);
1131 MCSymbol *EndLabel = std::get<1>(HeapAllocSite);
1133 // The labels might not be defined if the instruction was replaced
1134 // somewhere in the codegen pipeline.
1135 if (!BeginLabel->isDefined() || !EndLabel->isDefined())
1138 DIType *DITy = std::get<2>(HeapAllocSite);
1139 MCSymbol *HeapAllocEnd = beginSymbolRecord(SymbolKind::S_HEAPALLOCSITE);
1140 OS.AddComment("Call site offset");
1141 OS.EmitCOFFSecRel32(BeginLabel, /*Offset=*/0);
1142 OS.AddComment("Call site section index");
1143 OS.EmitCOFFSectionIndex(BeginLabel);
1144 OS.AddComment("Call instruction length");
1145 OS.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 2);
1146 OS.AddComment("Type index");
1147 OS.EmitIntValue(getCompleteTypeIndex(DITy).getIndex(), 4);
1148 endSymbolRecord(HeapAllocEnd);
1152 emitDebugInfoForUDTs(LocalUDTs);
1154 // We're done with this function.
1155 emitEndSymbolRecord(SymbolKind::S_PROC_ID_END);
1157 endCVSubsection(SymbolsEnd);
1159 // We have an assembler directive that takes care of the whole line table.
1160 OS.EmitCVLinetableDirective(FI.FuncId, Fn, FI.End);
1163 CodeViewDebug::LocalVarDefRange
1164 CodeViewDebug::createDefRangeMem(uint16_t CVRegister, int Offset) {
1165 LocalVarDefRange DR;
1167 DR.DataOffset = Offset;
1168 assert(DR.DataOffset == Offset && "truncation");
1170 DR.StructOffset = 0;
1171 DR.CVRegister = CVRegister;
1175 void CodeViewDebug::collectVariableInfoFromMFTable(
1176 DenseSet<InlinedEntity> &Processed) {
1177 const MachineFunction &MF = *Asm->MF;
1178 const TargetSubtargetInfo &TSI = MF.getSubtarget();
1179 const TargetFrameLowering *TFI = TSI.getFrameLowering();
1180 const TargetRegisterInfo *TRI = TSI.getRegisterInfo();
1182 for (const MachineFunction::VariableDbgInfo &VI : MF.getVariableDbgInfo()) {
1185 assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&
1186 "Expected inlined-at fields to agree");
1188 Processed.insert(InlinedEntity(VI.Var, VI.Loc->getInlinedAt()));
1189 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1191 // If variable scope is not found then skip this variable.
1195 // If the variable has an attached offset expression, extract it.
1196 // FIXME: Try to handle DW_OP_deref as well.
1197 int64_t ExprOffset = 0;
1200 // If there is one DW_OP_deref element, use offset of 0 and keep going.
1201 if (VI.Expr->getNumElements() == 1 &&
1202 VI.Expr->getElement(0) == llvm::dwarf::DW_OP_deref)
1204 else if (!VI.Expr->extractIfOffset(ExprOffset))
1208 // Get the frame register used and the offset.
1209 unsigned FrameReg = 0;
1210 int FrameOffset = TFI->getFrameIndexReference(*Asm->MF, VI.Slot, FrameReg);
1211 uint16_t CVReg = TRI->getCodeViewRegNum(FrameReg);
1213 // Calculate the label ranges.
1214 LocalVarDefRange DefRange =
1215 createDefRangeMem(CVReg, FrameOffset + ExprOffset);
1217 for (const InsnRange &Range : Scope->getRanges()) {
1218 const MCSymbol *Begin = getLabelBeforeInsn(Range.first);
1219 const MCSymbol *End = getLabelAfterInsn(Range.second);
1220 End = End ? End : Asm->getFunctionEnd();
1221 DefRange.Ranges.emplace_back(Begin, End);
1226 Var.DefRanges.emplace_back(std::move(DefRange));
1228 Var.UseReferenceType = true;
1230 recordLocalVariable(std::move(Var), Scope);
1234 static bool canUseReferenceType(const DbgVariableLocation &Loc) {
1235 return !Loc.LoadChain.empty() && Loc.LoadChain.back() == 0;
1238 static bool needsReferenceType(const DbgVariableLocation &Loc) {
1239 return Loc.LoadChain.size() == 2 && Loc.LoadChain.back() == 0;
1242 void CodeViewDebug::calculateRanges(
1243 LocalVariable &Var, const DbgValueHistoryMap::Entries &Entries) {
1244 const TargetRegisterInfo *TRI = Asm->MF->getSubtarget().getRegisterInfo();
1246 // Calculate the definition ranges.
1247 for (auto I = Entries.begin(), E = Entries.end(); I != E; ++I) {
1248 const auto &Entry = *I;
1249 if (!Entry.isDbgValue())
1251 const MachineInstr *DVInst = Entry.getInstr();
1252 assert(DVInst->isDebugValue() && "Invalid History entry");
1253 // FIXME: Find a way to represent constant variables, since they are
1254 // relatively common.
1255 Optional<DbgVariableLocation> Location =
1256 DbgVariableLocation::extractFromMachineInstruction(*DVInst);
1260 // CodeView can only express variables in register and variables in memory
1261 // at a constant offset from a register. However, for variables passed
1262 // indirectly by pointer, it is common for that pointer to be spilled to a
1263 // stack location. For the special case of one offseted load followed by a
1264 // zero offset load (a pointer spilled to the stack), we change the type of
1265 // the local variable from a value type to a reference type. This tricks the
1266 // debugger into doing the load for us.
1267 if (Var.UseReferenceType) {
1268 // We're using a reference type. Drop the last zero offset load.
1269 if (canUseReferenceType(*Location))
1270 Location->LoadChain.pop_back();
1273 } else if (needsReferenceType(*Location)) {
1274 // This location can't be expressed without switching to a reference type.
1275 // Start over using that.
1276 Var.UseReferenceType = true;
1277 Var.DefRanges.clear();
1278 calculateRanges(Var, Entries);
1282 // We can only handle a register or an offseted load of a register.
1283 if (Location->Register == 0 || Location->LoadChain.size() > 1)
1286 LocalVarDefRange DR;
1287 DR.CVRegister = TRI->getCodeViewRegNum(Location->Register);
1288 DR.InMemory = !Location->LoadChain.empty();
1290 !Location->LoadChain.empty() ? Location->LoadChain.back() : 0;
1291 if (Location->FragmentInfo) {
1292 DR.IsSubfield = true;
1293 DR.StructOffset = Location->FragmentInfo->OffsetInBits / 8;
1295 DR.IsSubfield = false;
1296 DR.StructOffset = 0;
1299 if (Var.DefRanges.empty() ||
1300 Var.DefRanges.back().isDifferentLocation(DR)) {
1301 Var.DefRanges.emplace_back(std::move(DR));
1305 // Compute the label range.
1306 const MCSymbol *Begin = getLabelBeforeInsn(Entry.getInstr());
1307 const MCSymbol *End;
1308 if (Entry.getEndIndex() != DbgValueHistoryMap::NoEntry) {
1309 auto &EndingEntry = Entries[Entry.getEndIndex()];
1310 End = EndingEntry.isDbgValue()
1311 ? getLabelBeforeInsn(EndingEntry.getInstr())
1312 : getLabelAfterInsn(EndingEntry.getInstr());
1314 End = Asm->getFunctionEnd();
1316 // If the last range end is our begin, just extend the last range.
1317 // Otherwise make a new range.
1318 SmallVectorImpl<std::pair<const MCSymbol *, const MCSymbol *>> &R =
1319 Var.DefRanges.back().Ranges;
1320 if (!R.empty() && R.back().second == Begin)
1321 R.back().second = End;
1323 R.emplace_back(Begin, End);
1325 // FIXME: Do more range combining.
1329 void CodeViewDebug::collectVariableInfo(const DISubprogram *SP) {
1330 DenseSet<InlinedEntity> Processed;
1331 // Grab the variable info that was squirreled away in the MMI side-table.
1332 collectVariableInfoFromMFTable(Processed);
1334 for (const auto &I : DbgValues) {
1335 InlinedEntity IV = I.first;
1336 if (Processed.count(IV))
1338 const DILocalVariable *DIVar = cast<DILocalVariable>(IV.first);
1339 const DILocation *InlinedAt = IV.second;
1341 // Instruction ranges, specifying where IV is accessible.
1342 const auto &Entries = I.second;
1344 LexicalScope *Scope = nullptr;
1346 Scope = LScopes.findInlinedScope(DIVar->getScope(), InlinedAt);
1348 Scope = LScopes.findLexicalScope(DIVar->getScope());
1349 // If variable scope is not found then skip this variable.
1356 calculateRanges(Var, Entries);
1357 recordLocalVariable(std::move(Var), Scope);
1361 void CodeViewDebug::beginFunctionImpl(const MachineFunction *MF) {
1362 const TargetSubtargetInfo &TSI = MF->getSubtarget();
1363 const TargetRegisterInfo *TRI = TSI.getRegisterInfo();
1364 const MachineFrameInfo &MFI = MF->getFrameInfo();
1365 const Function &GV = MF->getFunction();
1366 auto Insertion = FnDebugInfo.insert({&GV, llvm::make_unique<FunctionInfo>()});
1367 assert(Insertion.second && "function already has info");
1368 CurFn = Insertion.first->second.get();
1369 CurFn->FuncId = NextFuncId++;
1370 CurFn->Begin = Asm->getFunctionBegin();
1372 // The S_FRAMEPROC record reports the stack size, and how many bytes of
1373 // callee-saved registers were used. For targets that don't use a PUSH
1374 // instruction (AArch64), this will be zero.
1375 CurFn->CSRSize = MFI.getCVBytesOfCalleeSavedRegisters();
1376 CurFn->FrameSize = MFI.getStackSize();
1377 CurFn->OffsetAdjustment = MFI.getOffsetAdjustment();
1378 CurFn->HasStackRealignment = TRI->needsStackRealignment(*MF);
1380 // For this function S_FRAMEPROC record, figure out which codeview register
1381 // will be the frame pointer.
1382 CurFn->EncodedParamFramePtrReg = EncodedFramePtrReg::None; // None.
1383 CurFn->EncodedLocalFramePtrReg = EncodedFramePtrReg::None; // None.
1384 if (CurFn->FrameSize > 0) {
1385 if (!TSI.getFrameLowering()->hasFP(*MF)) {
1386 CurFn->EncodedLocalFramePtrReg = EncodedFramePtrReg::StackPtr;
1387 CurFn->EncodedParamFramePtrReg = EncodedFramePtrReg::StackPtr;
1389 // If there is an FP, parameters are always relative to it.
1390 CurFn->EncodedParamFramePtrReg = EncodedFramePtrReg::FramePtr;
1391 if (CurFn->HasStackRealignment) {
1392 // If the stack needs realignment, locals are relative to SP or VFRAME.
1393 CurFn->EncodedLocalFramePtrReg = EncodedFramePtrReg::StackPtr;
1395 // Otherwise, locals are relative to EBP, and we probably have VLAs or
1396 // other stack adjustments.
1397 CurFn->EncodedLocalFramePtrReg = EncodedFramePtrReg::FramePtr;
1402 // Compute other frame procedure options.
1403 FrameProcedureOptions FPO = FrameProcedureOptions::None;
1404 if (MFI.hasVarSizedObjects())
1405 FPO |= FrameProcedureOptions::HasAlloca;
1406 if (MF->exposesReturnsTwice())
1407 FPO |= FrameProcedureOptions::HasSetJmp;
1408 // FIXME: Set HasLongJmp if we ever track that info.
1409 if (MF->hasInlineAsm())
1410 FPO |= FrameProcedureOptions::HasInlineAssembly;
1411 if (GV.hasPersonalityFn()) {
1412 if (isAsynchronousEHPersonality(
1413 classifyEHPersonality(GV.getPersonalityFn())))
1414 FPO |= FrameProcedureOptions::HasStructuredExceptionHandling;
1416 FPO |= FrameProcedureOptions::HasExceptionHandling;
1418 if (GV.hasFnAttribute(Attribute::InlineHint))
1419 FPO |= FrameProcedureOptions::MarkedInline;
1420 if (GV.hasFnAttribute(Attribute::Naked))
1421 FPO |= FrameProcedureOptions::Naked;
1422 if (MFI.hasStackProtectorIndex())
1423 FPO |= FrameProcedureOptions::SecurityChecks;
1424 FPO |= FrameProcedureOptions(uint32_t(CurFn->EncodedLocalFramePtrReg) << 14U);
1425 FPO |= FrameProcedureOptions(uint32_t(CurFn->EncodedParamFramePtrReg) << 16U);
1426 if (Asm->TM.getOptLevel() != CodeGenOpt::None &&
1427 !GV.hasOptSize() && !GV.hasOptNone())
1428 FPO |= FrameProcedureOptions::OptimizedForSpeed;
1429 // FIXME: Set GuardCfg when it is implemented.
1430 CurFn->FrameProcOpts = FPO;
1432 OS.EmitCVFuncIdDirective(CurFn->FuncId);
1434 // Find the end of the function prolog. First known non-DBG_VALUE and
1435 // non-frame setup location marks the beginning of the function body.
1436 // FIXME: is there a simpler a way to do this? Can we just search
1437 // for the first instruction of the function, not the last of the prolog?
1438 DebugLoc PrologEndLoc;
1439 bool EmptyPrologue = true;
1440 for (const auto &MBB : *MF) {
1441 for (const auto &MI : MBB) {
1442 if (!MI.isMetaInstruction() && !MI.getFlag(MachineInstr::FrameSetup) &&
1444 PrologEndLoc = MI.getDebugLoc();
1446 } else if (!MI.isMetaInstruction()) {
1447 EmptyPrologue = false;
1452 // Record beginning of function if we have a non-empty prologue.
1453 if (PrologEndLoc && !EmptyPrologue) {
1454 DebugLoc FnStartDL = PrologEndLoc.getFnDebugLoc();
1455 maybeRecordLocation(FnStartDL, MF);
1459 static bool shouldEmitUdt(const DIType *T) {
1463 // MSVC does not emit UDTs for typedefs that are scoped to classes.
1464 if (T->getTag() == dwarf::DW_TAG_typedef) {
1465 if (DIScope *Scope = T->getScope()) {
1466 switch (Scope->getTag()) {
1467 case dwarf::DW_TAG_structure_type:
1468 case dwarf::DW_TAG_class_type:
1469 case dwarf::DW_TAG_union_type:
1476 if (!T || T->isForwardDecl())
1479 const DIDerivedType *DT = dyn_cast<DIDerivedType>(T);
1482 T = DT->getBaseType();
1487 void CodeViewDebug::addToUDTs(const DIType *Ty) {
1488 // Don't record empty UDTs.
1489 if (Ty->getName().empty())
1491 if (!shouldEmitUdt(Ty))
1494 SmallVector<StringRef, 5> QualifiedNameComponents;
1495 const DISubprogram *ClosestSubprogram =
1496 getQualifiedNameComponents(Ty->getScope(), QualifiedNameComponents);
1498 std::string FullyQualifiedName =
1499 getQualifiedName(QualifiedNameComponents, getPrettyScopeName(Ty));
1501 if (ClosestSubprogram == nullptr) {
1502 GlobalUDTs.emplace_back(std::move(FullyQualifiedName), Ty);
1503 } else if (ClosestSubprogram == CurrentSubprogram) {
1504 LocalUDTs.emplace_back(std::move(FullyQualifiedName), Ty);
1507 // TODO: What if the ClosestSubprogram is neither null or the current
1508 // subprogram? Currently, the UDT just gets dropped on the floor.
1510 // The current behavior is not desirable. To get maximal fidelity, we would
1511 // need to perform all type translation before beginning emission of .debug$S
1512 // and then make LocalUDTs a member of FunctionInfo
1515 TypeIndex CodeViewDebug::lowerType(const DIType *Ty, const DIType *ClassTy) {
1516 // Generic dispatch for lowering an unknown type.
1517 switch (Ty->getTag()) {
1518 case dwarf::DW_TAG_array_type:
1519 return lowerTypeArray(cast<DICompositeType>(Ty));
1520 case dwarf::DW_TAG_typedef:
1521 return lowerTypeAlias(cast<DIDerivedType>(Ty));
1522 case dwarf::DW_TAG_base_type:
1523 return lowerTypeBasic(cast<DIBasicType>(Ty));
1524 case dwarf::DW_TAG_pointer_type:
1525 if (cast<DIDerivedType>(Ty)->getName() == "__vtbl_ptr_type")
1526 return lowerTypeVFTableShape(cast<DIDerivedType>(Ty));
1528 case dwarf::DW_TAG_reference_type:
1529 case dwarf::DW_TAG_rvalue_reference_type:
1530 return lowerTypePointer(cast<DIDerivedType>(Ty));
1531 case dwarf::DW_TAG_ptr_to_member_type:
1532 return lowerTypeMemberPointer(cast<DIDerivedType>(Ty));
1533 case dwarf::DW_TAG_restrict_type:
1534 case dwarf::DW_TAG_const_type:
1535 case dwarf::DW_TAG_volatile_type:
1536 // TODO: add support for DW_TAG_atomic_type here
1537 return lowerTypeModifier(cast<DIDerivedType>(Ty));
1538 case dwarf::DW_TAG_subroutine_type:
1540 // The member function type of a member function pointer has no
1542 return lowerTypeMemberFunction(cast<DISubroutineType>(Ty), ClassTy,
1543 /*ThisAdjustment=*/0,
1544 /*IsStaticMethod=*/false);
1546 return lowerTypeFunction(cast<DISubroutineType>(Ty));
1547 case dwarf::DW_TAG_enumeration_type:
1548 return lowerTypeEnum(cast<DICompositeType>(Ty));
1549 case dwarf::DW_TAG_class_type:
1550 case dwarf::DW_TAG_structure_type:
1551 return lowerTypeClass(cast<DICompositeType>(Ty));
1552 case dwarf::DW_TAG_union_type:
1553 return lowerTypeUnion(cast<DICompositeType>(Ty));
1554 case dwarf::DW_TAG_unspecified_type:
1555 if (Ty->getName() == "decltype(nullptr)")
1556 return TypeIndex::NullptrT();
1557 return TypeIndex::None();
1559 // Use the null type index.
1564 TypeIndex CodeViewDebug::lowerTypeAlias(const DIDerivedType *Ty) {
1565 TypeIndex UnderlyingTypeIndex = getTypeIndex(Ty->getBaseType());
1566 StringRef TypeName = Ty->getName();
1570 if (UnderlyingTypeIndex == TypeIndex(SimpleTypeKind::Int32Long) &&
1571 TypeName == "HRESULT")
1572 return TypeIndex(SimpleTypeKind::HResult);
1573 if (UnderlyingTypeIndex == TypeIndex(SimpleTypeKind::UInt16Short) &&
1574 TypeName == "wchar_t")
1575 return TypeIndex(SimpleTypeKind::WideCharacter);
1577 return UnderlyingTypeIndex;
1580 TypeIndex CodeViewDebug::lowerTypeArray(const DICompositeType *Ty) {
1581 const DIType *ElementType = Ty->getBaseType();
1582 TypeIndex ElementTypeIndex = getTypeIndex(ElementType);
1583 // IndexType is size_t, which depends on the bitness of the target.
1584 TypeIndex IndexType = getPointerSizeInBytes() == 8
1585 ? TypeIndex(SimpleTypeKind::UInt64Quad)
1586 : TypeIndex(SimpleTypeKind::UInt32Long);
1588 uint64_t ElementSize = getBaseTypeSize(ElementType) / 8;
1590 // Add subranges to array type.
1591 DINodeArray Elements = Ty->getElements();
1592 for (int i = Elements.size() - 1; i >= 0; --i) {
1593 const DINode *Element = Elements[i];
1594 assert(Element->getTag() == dwarf::DW_TAG_subrange_type);
1596 const DISubrange *Subrange = cast<DISubrange>(Element);
1597 assert(Subrange->getLowerBound() == 0 &&
1598 "codeview doesn't support subranges with lower bounds");
1600 if (auto *CI = Subrange->getCount().dyn_cast<ConstantInt*>())
1601 Count = CI->getSExtValue();
1603 // Forward declarations of arrays without a size and VLAs use a count of -1.
1604 // Emit a count of zero in these cases to match what MSVC does for arrays
1605 // without a size. MSVC doesn't support VLAs, so it's not clear what we
1606 // should do for them even if we could distinguish them.
1610 // Update the element size and element type index for subsequent subranges.
1611 ElementSize *= Count;
1613 // If this is the outermost array, use the size from the array. It will be
1614 // more accurate if we had a VLA or an incomplete element type size.
1615 uint64_t ArraySize =
1616 (i == 0 && ElementSize == 0) ? Ty->getSizeInBits() / 8 : ElementSize;
1618 StringRef Name = (i == 0) ? Ty->getName() : "";
1619 ArrayRecord AR(ElementTypeIndex, IndexType, ArraySize, Name);
1620 ElementTypeIndex = TypeTable.writeLeafType(AR);
1623 return ElementTypeIndex;
1626 TypeIndex CodeViewDebug::lowerTypeBasic(const DIBasicType *Ty) {
1628 dwarf::TypeKind Kind;
1631 Kind = static_cast<dwarf::TypeKind>(Ty->getEncoding());
1632 ByteSize = Ty->getSizeInBits() / 8;
1634 SimpleTypeKind STK = SimpleTypeKind::None;
1636 case dwarf::DW_ATE_address:
1639 case dwarf::DW_ATE_boolean:
1641 case 1: STK = SimpleTypeKind::Boolean8; break;
1642 case 2: STK = SimpleTypeKind::Boolean16; break;
1643 case 4: STK = SimpleTypeKind::Boolean32; break;
1644 case 8: STK = SimpleTypeKind::Boolean64; break;
1645 case 16: STK = SimpleTypeKind::Boolean128; break;
1648 case dwarf::DW_ATE_complex_float:
1650 case 2: STK = SimpleTypeKind::Complex16; break;
1651 case 4: STK = SimpleTypeKind::Complex32; break;
1652 case 8: STK = SimpleTypeKind::Complex64; break;
1653 case 10: STK = SimpleTypeKind::Complex80; break;
1654 case 16: STK = SimpleTypeKind::Complex128; break;
1657 case dwarf::DW_ATE_float:
1659 case 2: STK = SimpleTypeKind::Float16; break;
1660 case 4: STK = SimpleTypeKind::Float32; break;
1661 case 6: STK = SimpleTypeKind::Float48; break;
1662 case 8: STK = SimpleTypeKind::Float64; break;
1663 case 10: STK = SimpleTypeKind::Float80; break;
1664 case 16: STK = SimpleTypeKind::Float128; break;
1667 case dwarf::DW_ATE_signed:
1669 case 1: STK = SimpleTypeKind::SignedCharacter; break;
1670 case 2: STK = SimpleTypeKind::Int16Short; break;
1671 case 4: STK = SimpleTypeKind::Int32; break;
1672 case 8: STK = SimpleTypeKind::Int64Quad; break;
1673 case 16: STK = SimpleTypeKind::Int128Oct; break;
1676 case dwarf::DW_ATE_unsigned:
1678 case 1: STK = SimpleTypeKind::UnsignedCharacter; break;
1679 case 2: STK = SimpleTypeKind::UInt16Short; break;
1680 case 4: STK = SimpleTypeKind::UInt32; break;
1681 case 8: STK = SimpleTypeKind::UInt64Quad; break;
1682 case 16: STK = SimpleTypeKind::UInt128Oct; break;
1685 case dwarf::DW_ATE_UTF:
1687 case 2: STK = SimpleTypeKind::Character16; break;
1688 case 4: STK = SimpleTypeKind::Character32; break;
1691 case dwarf::DW_ATE_signed_char:
1693 STK = SimpleTypeKind::SignedCharacter;
1695 case dwarf::DW_ATE_unsigned_char:
1697 STK = SimpleTypeKind::UnsignedCharacter;
1703 // Apply some fixups based on the source-level type name.
1704 if (STK == SimpleTypeKind::Int32 && Ty->getName() == "long int")
1705 STK = SimpleTypeKind::Int32Long;
1706 if (STK == SimpleTypeKind::UInt32 && Ty->getName() == "long unsigned int")
1707 STK = SimpleTypeKind::UInt32Long;
1708 if (STK == SimpleTypeKind::UInt16Short &&
1709 (Ty->getName() == "wchar_t" || Ty->getName() == "__wchar_t"))
1710 STK = SimpleTypeKind::WideCharacter;
1711 if ((STK == SimpleTypeKind::SignedCharacter ||
1712 STK == SimpleTypeKind::UnsignedCharacter) &&
1713 Ty->getName() == "char")
1714 STK = SimpleTypeKind::NarrowCharacter;
1716 return TypeIndex(STK);
1719 TypeIndex CodeViewDebug::lowerTypePointer(const DIDerivedType *Ty,
1720 PointerOptions PO) {
1721 TypeIndex PointeeTI = getTypeIndex(Ty->getBaseType());
1723 // Pointers to simple types without any options can use SimpleTypeMode, rather
1724 // than having a dedicated pointer type record.
1725 if (PointeeTI.isSimple() && PO == PointerOptions::None &&
1726 PointeeTI.getSimpleMode() == SimpleTypeMode::Direct &&
1727 Ty->getTag() == dwarf::DW_TAG_pointer_type) {
1728 SimpleTypeMode Mode = Ty->getSizeInBits() == 64
1729 ? SimpleTypeMode::NearPointer64
1730 : SimpleTypeMode::NearPointer32;
1731 return TypeIndex(PointeeTI.getSimpleKind(), Mode);
1735 Ty->getSizeInBits() == 64 ? PointerKind::Near64 : PointerKind::Near32;
1736 PointerMode PM = PointerMode::Pointer;
1737 switch (Ty->getTag()) {
1738 default: llvm_unreachable("not a pointer tag type");
1739 case dwarf::DW_TAG_pointer_type:
1740 PM = PointerMode::Pointer;
1742 case dwarf::DW_TAG_reference_type:
1743 PM = PointerMode::LValueReference;
1745 case dwarf::DW_TAG_rvalue_reference_type:
1746 PM = PointerMode::RValueReference;
1750 if (Ty->isObjectPointer())
1751 PO |= PointerOptions::Const;
1753 PointerRecord PR(PointeeTI, PK, PM, PO, Ty->getSizeInBits() / 8);
1754 return TypeTable.writeLeafType(PR);
1757 static PointerToMemberRepresentation
1758 translatePtrToMemberRep(unsigned SizeInBytes, bool IsPMF, unsigned Flags) {
1759 // SizeInBytes being zero generally implies that the member pointer type was
1760 // incomplete, which can happen if it is part of a function prototype. In this
1761 // case, use the unknown model instead of the general model.
1763 switch (Flags & DINode::FlagPtrToMemberRep) {
1765 return SizeInBytes == 0 ? PointerToMemberRepresentation::Unknown
1766 : PointerToMemberRepresentation::GeneralFunction;
1767 case DINode::FlagSingleInheritance:
1768 return PointerToMemberRepresentation::SingleInheritanceFunction;
1769 case DINode::FlagMultipleInheritance:
1770 return PointerToMemberRepresentation::MultipleInheritanceFunction;
1771 case DINode::FlagVirtualInheritance:
1772 return PointerToMemberRepresentation::VirtualInheritanceFunction;
1775 switch (Flags & DINode::FlagPtrToMemberRep) {
1777 return SizeInBytes == 0 ? PointerToMemberRepresentation::Unknown
1778 : PointerToMemberRepresentation::GeneralData;
1779 case DINode::FlagSingleInheritance:
1780 return PointerToMemberRepresentation::SingleInheritanceData;
1781 case DINode::FlagMultipleInheritance:
1782 return PointerToMemberRepresentation::MultipleInheritanceData;
1783 case DINode::FlagVirtualInheritance:
1784 return PointerToMemberRepresentation::VirtualInheritanceData;
1787 llvm_unreachable("invalid ptr to member representation");
1790 TypeIndex CodeViewDebug::lowerTypeMemberPointer(const DIDerivedType *Ty,
1791 PointerOptions PO) {
1792 assert(Ty->getTag() == dwarf::DW_TAG_ptr_to_member_type);
1793 TypeIndex ClassTI = getTypeIndex(Ty->getClassType());
1794 TypeIndex PointeeTI = getTypeIndex(Ty->getBaseType(), Ty->getClassType());
1795 PointerKind PK = getPointerSizeInBytes() == 8 ? PointerKind::Near64
1796 : PointerKind::Near32;
1797 bool IsPMF = isa<DISubroutineType>(Ty->getBaseType());
1798 PointerMode PM = IsPMF ? PointerMode::PointerToMemberFunction
1799 : PointerMode::PointerToDataMember;
1801 assert(Ty->getSizeInBits() / 8 <= 0xff && "pointer size too big");
1802 uint8_t SizeInBytes = Ty->getSizeInBits() / 8;
1803 MemberPointerInfo MPI(
1804 ClassTI, translatePtrToMemberRep(SizeInBytes, IsPMF, Ty->getFlags()));
1805 PointerRecord PR(PointeeTI, PK, PM, PO, SizeInBytes, MPI);
1806 return TypeTable.writeLeafType(PR);
1809 /// Given a DWARF calling convention, get the CodeView equivalent. If we don't
1810 /// have a translation, use the NearC convention.
1811 static CallingConvention dwarfCCToCodeView(unsigned DwarfCC) {
1813 case dwarf::DW_CC_normal: return CallingConvention::NearC;
1814 case dwarf::DW_CC_BORLAND_msfastcall: return CallingConvention::NearFast;
1815 case dwarf::DW_CC_BORLAND_thiscall: return CallingConvention::ThisCall;
1816 case dwarf::DW_CC_BORLAND_stdcall: return CallingConvention::NearStdCall;
1817 case dwarf::DW_CC_BORLAND_pascal: return CallingConvention::NearPascal;
1818 case dwarf::DW_CC_LLVM_vectorcall: return CallingConvention::NearVector;
1820 return CallingConvention::NearC;
1823 TypeIndex CodeViewDebug::lowerTypeModifier(const DIDerivedType *Ty) {
1824 ModifierOptions Mods = ModifierOptions::None;
1825 PointerOptions PO = PointerOptions::None;
1826 bool IsModifier = true;
1827 const DIType *BaseTy = Ty;
1828 while (IsModifier && BaseTy) {
1829 // FIXME: Need to add DWARF tags for __unaligned and _Atomic
1830 switch (BaseTy->getTag()) {
1831 case dwarf::DW_TAG_const_type:
1832 Mods |= ModifierOptions::Const;
1833 PO |= PointerOptions::Const;
1835 case dwarf::DW_TAG_volatile_type:
1836 Mods |= ModifierOptions::Volatile;
1837 PO |= PointerOptions::Volatile;
1839 case dwarf::DW_TAG_restrict_type:
1840 // Only pointer types be marked with __restrict. There is no known flag
1841 // for __restrict in LF_MODIFIER records.
1842 PO |= PointerOptions::Restrict;
1849 BaseTy = cast<DIDerivedType>(BaseTy)->getBaseType();
1852 // Check if the inner type will use an LF_POINTER record. If so, the
1853 // qualifiers will go in the LF_POINTER record. This comes up for types like
1854 // 'int *const' and 'int *__restrict', not the more common cases like 'const
1857 switch (BaseTy->getTag()) {
1858 case dwarf::DW_TAG_pointer_type:
1859 case dwarf::DW_TAG_reference_type:
1860 case dwarf::DW_TAG_rvalue_reference_type:
1861 return lowerTypePointer(cast<DIDerivedType>(BaseTy), PO);
1862 case dwarf::DW_TAG_ptr_to_member_type:
1863 return lowerTypeMemberPointer(cast<DIDerivedType>(BaseTy), PO);
1869 TypeIndex ModifiedTI = getTypeIndex(BaseTy);
1871 // Return the base type index if there aren't any modifiers. For example, the
1872 // metadata could contain restrict wrappers around non-pointer types.
1873 if (Mods == ModifierOptions::None)
1876 ModifierRecord MR(ModifiedTI, Mods);
1877 return TypeTable.writeLeafType(MR);
1880 TypeIndex CodeViewDebug::lowerTypeFunction(const DISubroutineType *Ty) {
1881 SmallVector<TypeIndex, 8> ReturnAndArgTypeIndices;
1882 for (const DIType *ArgType : Ty->getTypeArray())
1883 ReturnAndArgTypeIndices.push_back(getTypeIndex(ArgType));
1885 // MSVC uses type none for variadic argument.
1886 if (ReturnAndArgTypeIndices.size() > 1 &&
1887 ReturnAndArgTypeIndices.back() == TypeIndex::Void()) {
1888 ReturnAndArgTypeIndices.back() = TypeIndex::None();
1890 TypeIndex ReturnTypeIndex = TypeIndex::Void();
1891 ArrayRef<TypeIndex> ArgTypeIndices = None;
1892 if (!ReturnAndArgTypeIndices.empty()) {
1893 auto ReturnAndArgTypesRef = makeArrayRef(ReturnAndArgTypeIndices);
1894 ReturnTypeIndex = ReturnAndArgTypesRef.front();
1895 ArgTypeIndices = ReturnAndArgTypesRef.drop_front();
1898 ArgListRecord ArgListRec(TypeRecordKind::ArgList, ArgTypeIndices);
1899 TypeIndex ArgListIndex = TypeTable.writeLeafType(ArgListRec);
1901 CallingConvention CC = dwarfCCToCodeView(Ty->getCC());
1903 FunctionOptions FO = getFunctionOptions(Ty);
1904 ProcedureRecord Procedure(ReturnTypeIndex, CC, FO, ArgTypeIndices.size(),
1906 return TypeTable.writeLeafType(Procedure);
1909 TypeIndex CodeViewDebug::lowerTypeMemberFunction(const DISubroutineType *Ty,
1910 const DIType *ClassTy,
1912 bool IsStaticMethod,
1913 FunctionOptions FO) {
1914 // Lower the containing class type.
1915 TypeIndex ClassType = getTypeIndex(ClassTy);
1917 DITypeRefArray ReturnAndArgs = Ty->getTypeArray();
1920 SmallVector<TypeIndex, 8> ArgTypeIndices;
1921 TypeIndex ReturnTypeIndex = TypeIndex::Void();
1922 if (ReturnAndArgs.size() > Index) {
1923 ReturnTypeIndex = getTypeIndex(ReturnAndArgs[Index++]);
1926 // If the first argument is a pointer type and this isn't a static method,
1927 // treat it as the special 'this' parameter, which is encoded separately from
1929 TypeIndex ThisTypeIndex;
1930 if (!IsStaticMethod && ReturnAndArgs.size() > Index) {
1931 if (const DIDerivedType *PtrTy =
1932 dyn_cast_or_null<DIDerivedType>(ReturnAndArgs[Index])) {
1933 if (PtrTy->getTag() == dwarf::DW_TAG_pointer_type) {
1934 ThisTypeIndex = getTypeIndexForThisPtr(PtrTy, Ty);
1940 while (Index < ReturnAndArgs.size())
1941 ArgTypeIndices.push_back(getTypeIndex(ReturnAndArgs[Index++]));
1943 // MSVC uses type none for variadic argument.
1944 if (!ArgTypeIndices.empty() && ArgTypeIndices.back() == TypeIndex::Void())
1945 ArgTypeIndices.back() = TypeIndex::None();
1947 ArgListRecord ArgListRec(TypeRecordKind::ArgList, ArgTypeIndices);
1948 TypeIndex ArgListIndex = TypeTable.writeLeafType(ArgListRec);
1950 CallingConvention CC = dwarfCCToCodeView(Ty->getCC());
1952 MemberFunctionRecord MFR(ReturnTypeIndex, ClassType, ThisTypeIndex, CC, FO,
1953 ArgTypeIndices.size(), ArgListIndex, ThisAdjustment);
1954 return TypeTable.writeLeafType(MFR);
1957 TypeIndex CodeViewDebug::lowerTypeVFTableShape(const DIDerivedType *Ty) {
1958 unsigned VSlotCount =
1959 Ty->getSizeInBits() / (8 * Asm->MAI->getCodePointerSize());
1960 SmallVector<VFTableSlotKind, 4> Slots(VSlotCount, VFTableSlotKind::Near);
1962 VFTableShapeRecord VFTSR(Slots);
1963 return TypeTable.writeLeafType(VFTSR);
1966 static MemberAccess translateAccessFlags(unsigned RecordTag, unsigned Flags) {
1967 switch (Flags & DINode::FlagAccessibility) {
1968 case DINode::FlagPrivate: return MemberAccess::Private;
1969 case DINode::FlagPublic: return MemberAccess::Public;
1970 case DINode::FlagProtected: return MemberAccess::Protected;
1972 // If there was no explicit access control, provide the default for the tag.
1973 return RecordTag == dwarf::DW_TAG_class_type ? MemberAccess::Private
1974 : MemberAccess::Public;
1976 llvm_unreachable("access flags are exclusive");
1979 static MethodOptions translateMethodOptionFlags(const DISubprogram *SP) {
1980 if (SP->isArtificial())
1981 return MethodOptions::CompilerGenerated;
1983 // FIXME: Handle other MethodOptions.
1985 return MethodOptions::None;
1988 static MethodKind translateMethodKindFlags(const DISubprogram *SP,
1990 if (SP->getFlags() & DINode::FlagStaticMember)
1991 return MethodKind::Static;
1993 switch (SP->getVirtuality()) {
1994 case dwarf::DW_VIRTUALITY_none:
1996 case dwarf::DW_VIRTUALITY_virtual:
1997 return Introduced ? MethodKind::IntroducingVirtual : MethodKind::Virtual;
1998 case dwarf::DW_VIRTUALITY_pure_virtual:
1999 return Introduced ? MethodKind::PureIntroducingVirtual
2000 : MethodKind::PureVirtual;
2002 llvm_unreachable("unhandled virtuality case");
2005 return MethodKind::Vanilla;
2008 static TypeRecordKind getRecordKind(const DICompositeType *Ty) {
2009 switch (Ty->getTag()) {
2010 case dwarf::DW_TAG_class_type: return TypeRecordKind::Class;
2011 case dwarf::DW_TAG_structure_type: return TypeRecordKind::Struct;
2013 llvm_unreachable("unexpected tag");
2016 /// Return ClassOptions that should be present on both the forward declaration
2017 /// and the defintion of a tag type.
2018 static ClassOptions getCommonClassOptions(const DICompositeType *Ty) {
2019 ClassOptions CO = ClassOptions::None;
2021 // MSVC always sets this flag, even for local types. Clang doesn't always
2022 // appear to give every type a linkage name, which may be problematic for us.
2023 // FIXME: Investigate the consequences of not following them here.
2024 if (!Ty->getIdentifier().empty())
2025 CO |= ClassOptions::HasUniqueName;
2027 // Put the Nested flag on a type if it appears immediately inside a tag type.
2028 // Do not walk the scope chain. Do not attempt to compute ContainsNestedClass
2029 // here. That flag is only set on definitions, and not forward declarations.
2030 const DIScope *ImmediateScope = Ty->getScope();
2031 if (ImmediateScope && isa<DICompositeType>(ImmediateScope))
2032 CO |= ClassOptions::Nested;
2034 // Put the Scoped flag on function-local types. MSVC puts this flag for enum
2035 // type only when it has an immediate function scope. Clang never puts enums
2036 // inside DILexicalBlock scopes. Enum types, as generated by clang, are
2037 // always in function, class, or file scopes.
2038 if (Ty->getTag() == dwarf::DW_TAG_enumeration_type) {
2039 if (ImmediateScope && isa<DISubprogram>(ImmediateScope))
2040 CO |= ClassOptions::Scoped;
2042 for (const DIScope *Scope = ImmediateScope; Scope != nullptr;
2043 Scope = Scope->getScope()) {
2044 if (isa<DISubprogram>(Scope)) {
2045 CO |= ClassOptions::Scoped;
2054 void CodeViewDebug::addUDTSrcLine(const DIType *Ty, TypeIndex TI) {
2055 switch (Ty->getTag()) {
2056 case dwarf::DW_TAG_class_type:
2057 case dwarf::DW_TAG_structure_type:
2058 case dwarf::DW_TAG_union_type:
2059 case dwarf::DW_TAG_enumeration_type:
2065 if (const auto *File = Ty->getFile()) {
2066 StringIdRecord SIDR(TypeIndex(0x0), getFullFilepath(File));
2067 TypeIndex SIDI = TypeTable.writeLeafType(SIDR);
2069 UdtSourceLineRecord USLR(TI, SIDI, Ty->getLine());
2070 TypeTable.writeLeafType(USLR);
2074 TypeIndex CodeViewDebug::lowerTypeEnum(const DICompositeType *Ty) {
2075 ClassOptions CO = getCommonClassOptions(Ty);
2077 unsigned EnumeratorCount = 0;
2079 if (Ty->isForwardDecl()) {
2080 CO |= ClassOptions::ForwardReference;
2082 ContinuationRecordBuilder ContinuationBuilder;
2083 ContinuationBuilder.begin(ContinuationRecordKind::FieldList);
2084 for (const DINode *Element : Ty->getElements()) {
2085 // We assume that the frontend provides all members in source declaration
2086 // order, which is what MSVC does.
2087 if (auto *Enumerator = dyn_cast_or_null<DIEnumerator>(Element)) {
2088 EnumeratorRecord ER(MemberAccess::Public,
2089 APSInt::getUnsigned(Enumerator->getValue()),
2090 Enumerator->getName());
2091 ContinuationBuilder.writeMemberType(ER);
2095 FTI = TypeTable.insertRecord(ContinuationBuilder);
2098 std::string FullName = getFullyQualifiedName(Ty);
2100 EnumRecord ER(EnumeratorCount, CO, FTI, FullName, Ty->getIdentifier(),
2101 getTypeIndex(Ty->getBaseType()));
2102 TypeIndex EnumTI = TypeTable.writeLeafType(ER);
2104 addUDTSrcLine(Ty, EnumTI);
2109 //===----------------------------------------------------------------------===//
2111 //===----------------------------------------------------------------------===//
2113 struct llvm::ClassInfo {
2115 const DIDerivedType *MemberTypeNode;
2116 uint64_t BaseOffset;
2119 using MemberList = std::vector<MemberInfo>;
2121 using MethodsList = TinyPtrVector<const DISubprogram *>;
2122 // MethodName -> MethodsList
2123 using MethodsMap = MapVector<MDString *, MethodsList>;
2126 std::vector<const DIDerivedType *> Inheritance;
2130 // Direct overloaded methods gathered by name.
2135 std::vector<const DIType *> NestedTypes;
2138 void CodeViewDebug::clear() {
2139 assert(CurFn == nullptr);
2141 FnDebugInfo.clear();
2142 FileToFilepathMap.clear();
2145 TypeIndices.clear();
2146 CompleteTypeIndices.clear();
2147 ScopeGlobals.clear();
2150 void CodeViewDebug::collectMemberInfo(ClassInfo &Info,
2151 const DIDerivedType *DDTy) {
2152 if (!DDTy->getName().empty()) {
2153 Info.Members.push_back({DDTy, 0});
2157 // An unnamed member may represent a nested struct or union. Attempt to
2158 // interpret the unnamed member as a DICompositeType possibly wrapped in
2159 // qualifier types. Add all the indirect fields to the current record if that
2160 // succeeds, and drop the member if that fails.
2161 assert((DDTy->getOffsetInBits() % 8) == 0 && "Unnamed bitfield member!");
2162 uint64_t Offset = DDTy->getOffsetInBits();
2163 const DIType *Ty = DDTy->getBaseType();
2164 bool FullyResolved = false;
2165 while (!FullyResolved) {
2166 switch (Ty->getTag()) {
2167 case dwarf::DW_TAG_const_type:
2168 case dwarf::DW_TAG_volatile_type:
2169 // FIXME: we should apply the qualifier types to the indirect fields
2170 // rather than dropping them.
2171 Ty = cast<DIDerivedType>(Ty)->getBaseType();
2174 FullyResolved = true;
2179 const DICompositeType *DCTy = dyn_cast<DICompositeType>(Ty);
2183 ClassInfo NestedInfo = collectClassInfo(DCTy);
2184 for (const ClassInfo::MemberInfo &IndirectField : NestedInfo.Members)
2185 Info.Members.push_back(
2186 {IndirectField.MemberTypeNode, IndirectField.BaseOffset + Offset});
2189 ClassInfo CodeViewDebug::collectClassInfo(const DICompositeType *Ty) {
2191 // Add elements to structure type.
2192 DINodeArray Elements = Ty->getElements();
2193 for (auto *Element : Elements) {
2194 // We assume that the frontend provides all members in source declaration
2195 // order, which is what MSVC does.
2198 if (auto *SP = dyn_cast<DISubprogram>(Element)) {
2199 Info.Methods[SP->getRawName()].push_back(SP);
2200 } else if (auto *DDTy = dyn_cast<DIDerivedType>(Element)) {
2201 if (DDTy->getTag() == dwarf::DW_TAG_member) {
2202 collectMemberInfo(Info, DDTy);
2203 } else if (DDTy->getTag() == dwarf::DW_TAG_inheritance) {
2204 Info.Inheritance.push_back(DDTy);
2205 } else if (DDTy->getTag() == dwarf::DW_TAG_pointer_type &&
2206 DDTy->getName() == "__vtbl_ptr_type") {
2207 Info.VShapeTI = getTypeIndex(DDTy);
2208 } else if (DDTy->getTag() == dwarf::DW_TAG_typedef) {
2209 Info.NestedTypes.push_back(DDTy);
2210 } else if (DDTy->getTag() == dwarf::DW_TAG_friend) {
2211 // Ignore friend members. It appears that MSVC emitted info about
2212 // friends in the past, but modern versions do not.
2214 } else if (auto *Composite = dyn_cast<DICompositeType>(Element)) {
2215 Info.NestedTypes.push_back(Composite);
2217 // Skip other unrecognized kinds of elements.
2222 static bool shouldAlwaysEmitCompleteClassType(const DICompositeType *Ty) {
2223 // This routine is used by lowerTypeClass and lowerTypeUnion to determine
2224 // if a complete type should be emitted instead of a forward reference.
2225 return Ty->getName().empty() && Ty->getIdentifier().empty() &&
2226 !Ty->isForwardDecl();
2229 TypeIndex CodeViewDebug::lowerTypeClass(const DICompositeType *Ty) {
2230 // Emit the complete type for unnamed structs. C++ classes with methods
2231 // which have a circular reference back to the class type are expected to
2232 // be named by the front-end and should not be "unnamed". C unnamed
2233 // structs should not have circular references.
2234 if (shouldAlwaysEmitCompleteClassType(Ty)) {
2235 // If this unnamed complete type is already in the process of being defined
2236 // then the description of the type is malformed and cannot be emitted
2237 // into CodeView correctly so report a fatal error.
2238 auto I = CompleteTypeIndices.find(Ty);
2239 if (I != CompleteTypeIndices.end() && I->second == TypeIndex())
2240 report_fatal_error("cannot debug circular reference to unnamed type");
2241 return getCompleteTypeIndex(Ty);
2244 // First, construct the forward decl. Don't look into Ty to compute the
2245 // forward decl options, since it might not be available in all TUs.
2246 TypeRecordKind Kind = getRecordKind(Ty);
2248 ClassOptions::ForwardReference | getCommonClassOptions(Ty);
2249 std::string FullName = getFullyQualifiedName(Ty);
2250 ClassRecord CR(Kind, 0, CO, TypeIndex(), TypeIndex(), TypeIndex(), 0,
2251 FullName, Ty->getIdentifier());
2252 TypeIndex FwdDeclTI = TypeTable.writeLeafType(CR);
2253 if (!Ty->isForwardDecl())
2254 DeferredCompleteTypes.push_back(Ty);
2258 TypeIndex CodeViewDebug::lowerCompleteTypeClass(const DICompositeType *Ty) {
2259 // Construct the field list and complete type record.
2260 TypeRecordKind Kind = getRecordKind(Ty);
2261 ClassOptions CO = getCommonClassOptions(Ty);
2264 unsigned FieldCount;
2265 bool ContainsNestedClass;
2266 std::tie(FieldTI, VShapeTI, FieldCount, ContainsNestedClass) =
2267 lowerRecordFieldList(Ty);
2269 if (ContainsNestedClass)
2270 CO |= ClassOptions::ContainsNestedClass;
2272 // MSVC appears to set this flag by searching any destructor or method with
2273 // FunctionOptions::Constructor among the emitted members. Clang AST has all
2274 // the members, however special member functions are not yet emitted into
2275 // debug information. For now checking a class's non-triviality seems enough.
2276 // FIXME: not true for a nested unnamed struct.
2277 if (isNonTrivial(Ty))
2278 CO |= ClassOptions::HasConstructorOrDestructor;
2280 std::string FullName = getFullyQualifiedName(Ty);
2282 uint64_t SizeInBytes = Ty->getSizeInBits() / 8;
2284 ClassRecord CR(Kind, FieldCount, CO, FieldTI, TypeIndex(), VShapeTI,
2285 SizeInBytes, FullName, Ty->getIdentifier());
2286 TypeIndex ClassTI = TypeTable.writeLeafType(CR);
2288 addUDTSrcLine(Ty, ClassTI);
2295 TypeIndex CodeViewDebug::lowerTypeUnion(const DICompositeType *Ty) {
2296 // Emit the complete type for unnamed unions.
2297 if (shouldAlwaysEmitCompleteClassType(Ty))
2298 return getCompleteTypeIndex(Ty);
2301 ClassOptions::ForwardReference | getCommonClassOptions(Ty);
2302 std::string FullName = getFullyQualifiedName(Ty);
2303 UnionRecord UR(0, CO, TypeIndex(), 0, FullName, Ty->getIdentifier());
2304 TypeIndex FwdDeclTI = TypeTable.writeLeafType(UR);
2305 if (!Ty->isForwardDecl())
2306 DeferredCompleteTypes.push_back(Ty);
2310 TypeIndex CodeViewDebug::lowerCompleteTypeUnion(const DICompositeType *Ty) {
2311 ClassOptions CO = ClassOptions::Sealed | getCommonClassOptions(Ty);
2313 unsigned FieldCount;
2314 bool ContainsNestedClass;
2315 std::tie(FieldTI, std::ignore, FieldCount, ContainsNestedClass) =
2316 lowerRecordFieldList(Ty);
2318 if (ContainsNestedClass)
2319 CO |= ClassOptions::ContainsNestedClass;
2321 uint64_t SizeInBytes = Ty->getSizeInBits() / 8;
2322 std::string FullName = getFullyQualifiedName(Ty);
2324 UnionRecord UR(FieldCount, CO, FieldTI, SizeInBytes, FullName,
2325 Ty->getIdentifier());
2326 TypeIndex UnionTI = TypeTable.writeLeafType(UR);
2328 addUDTSrcLine(Ty, UnionTI);
2335 std::tuple<TypeIndex, TypeIndex, unsigned, bool>
2336 CodeViewDebug::lowerRecordFieldList(const DICompositeType *Ty) {
2337 // Manually count members. MSVC appears to count everything that generates a
2338 // field list record. Each individual overload in a method overload group
2339 // contributes to this count, even though the overload group is a single field
2341 unsigned MemberCount = 0;
2342 ClassInfo Info = collectClassInfo(Ty);
2343 ContinuationRecordBuilder ContinuationBuilder;
2344 ContinuationBuilder.begin(ContinuationRecordKind::FieldList);
2346 // Create base classes.
2347 for (const DIDerivedType *I : Info.Inheritance) {
2348 if (I->getFlags() & DINode::FlagVirtual) {
2350 unsigned VBPtrOffset = I->getVBPtrOffset();
2351 // FIXME: Despite the accessor name, the offset is really in bytes.
2352 unsigned VBTableIndex = I->getOffsetInBits() / 4;
2353 auto RecordKind = (I->getFlags() & DINode::FlagIndirectVirtualBase) == DINode::FlagIndirectVirtualBase
2354 ? TypeRecordKind::IndirectVirtualBaseClass
2355 : TypeRecordKind::VirtualBaseClass;
2356 VirtualBaseClassRecord VBCR(
2357 RecordKind, translateAccessFlags(Ty->getTag(), I->getFlags()),
2358 getTypeIndex(I->getBaseType()), getVBPTypeIndex(), VBPtrOffset,
2361 ContinuationBuilder.writeMemberType(VBCR);
2364 assert(I->getOffsetInBits() % 8 == 0 &&
2365 "bases must be on byte boundaries");
2366 BaseClassRecord BCR(translateAccessFlags(Ty->getTag(), I->getFlags()),
2367 getTypeIndex(I->getBaseType()),
2368 I->getOffsetInBits() / 8);
2369 ContinuationBuilder.writeMemberType(BCR);
2375 for (ClassInfo::MemberInfo &MemberInfo : Info.Members) {
2376 const DIDerivedType *Member = MemberInfo.MemberTypeNode;
2377 TypeIndex MemberBaseType = getTypeIndex(Member->getBaseType());
2378 StringRef MemberName = Member->getName();
2379 MemberAccess Access =
2380 translateAccessFlags(Ty->getTag(), Member->getFlags());
2382 if (Member->isStaticMember()) {
2383 StaticDataMemberRecord SDMR(Access, MemberBaseType, MemberName);
2384 ContinuationBuilder.writeMemberType(SDMR);
2389 // Virtual function pointer member.
2390 if ((Member->getFlags() & DINode::FlagArtificial) &&
2391 Member->getName().startswith("_vptr$")) {
2392 VFPtrRecord VFPR(getTypeIndex(Member->getBaseType()));
2393 ContinuationBuilder.writeMemberType(VFPR);
2399 uint64_t MemberOffsetInBits =
2400 Member->getOffsetInBits() + MemberInfo.BaseOffset;
2401 if (Member->isBitField()) {
2402 uint64_t StartBitOffset = MemberOffsetInBits;
2403 if (const auto *CI =
2404 dyn_cast_or_null<ConstantInt>(Member->getStorageOffsetInBits())) {
2405 MemberOffsetInBits = CI->getZExtValue() + MemberInfo.BaseOffset;
2407 StartBitOffset -= MemberOffsetInBits;
2408 BitFieldRecord BFR(MemberBaseType, Member->getSizeInBits(),
2410 MemberBaseType = TypeTable.writeLeafType(BFR);
2412 uint64_t MemberOffsetInBytes = MemberOffsetInBits / 8;
2413 DataMemberRecord DMR(Access, MemberBaseType, MemberOffsetInBytes,
2415 ContinuationBuilder.writeMemberType(DMR);
2420 for (auto &MethodItr : Info.Methods) {
2421 StringRef Name = MethodItr.first->getString();
2423 std::vector<OneMethodRecord> Methods;
2424 for (const DISubprogram *SP : MethodItr.second) {
2425 TypeIndex MethodType = getMemberFunctionType(SP, Ty);
2426 bool Introduced = SP->getFlags() & DINode::FlagIntroducedVirtual;
2428 unsigned VFTableOffset = -1;
2430 VFTableOffset = SP->getVirtualIndex() * getPointerSizeInBytes();
2432 Methods.push_back(OneMethodRecord(
2433 MethodType, translateAccessFlags(Ty->getTag(), SP->getFlags()),
2434 translateMethodKindFlags(SP, Introduced),
2435 translateMethodOptionFlags(SP), VFTableOffset, Name));
2438 assert(!Methods.empty() && "Empty methods map entry");
2439 if (Methods.size() == 1)
2440 ContinuationBuilder.writeMemberType(Methods[0]);
2442 // FIXME: Make this use its own ContinuationBuilder so that
2443 // MethodOverloadList can be split correctly.
2444 MethodOverloadListRecord MOLR(Methods);
2445 TypeIndex MethodList = TypeTable.writeLeafType(MOLR);
2447 OverloadedMethodRecord OMR(Methods.size(), MethodList, Name);
2448 ContinuationBuilder.writeMemberType(OMR);
2452 // Create nested classes.
2453 for (const DIType *Nested : Info.NestedTypes) {
2454 NestedTypeRecord R(getTypeIndex(Nested), Nested->getName());
2455 ContinuationBuilder.writeMemberType(R);
2459 TypeIndex FieldTI = TypeTable.insertRecord(ContinuationBuilder);
2460 return std::make_tuple(FieldTI, Info.VShapeTI, MemberCount,
2461 !Info.NestedTypes.empty());
2464 TypeIndex CodeViewDebug::getVBPTypeIndex() {
2465 if (!VBPType.getIndex()) {
2466 // Make a 'const int *' type.
2467 ModifierRecord MR(TypeIndex::Int32(), ModifierOptions::Const);
2468 TypeIndex ModifiedTI = TypeTable.writeLeafType(MR);
2470 PointerKind PK = getPointerSizeInBytes() == 8 ? PointerKind::Near64
2471 : PointerKind::Near32;
2472 PointerMode PM = PointerMode::Pointer;
2473 PointerOptions PO = PointerOptions::None;
2474 PointerRecord PR(ModifiedTI, PK, PM, PO, getPointerSizeInBytes());
2475 VBPType = TypeTable.writeLeafType(PR);
2481 TypeIndex CodeViewDebug::getTypeIndex(const DIType *Ty, const DIType *ClassTy) {
2482 // The null DIType is the void type. Don't try to hash it.
2484 return TypeIndex::Void();
2486 // Check if we've already translated this type. Don't try to do a
2487 // get-or-create style insertion that caches the hash lookup across the
2488 // lowerType call. It will update the TypeIndices map.
2489 auto I = TypeIndices.find({Ty, ClassTy});
2490 if (I != TypeIndices.end())
2493 TypeLoweringScope S(*this);
2494 TypeIndex TI = lowerType(Ty, ClassTy);
2495 return recordTypeIndexForDINode(Ty, TI, ClassTy);
2499 CodeViewDebug::getTypeIndexForThisPtr(const DIDerivedType *PtrTy,
2500 const DISubroutineType *SubroutineTy) {
2501 assert(PtrTy->getTag() == dwarf::DW_TAG_pointer_type &&
2502 "this type must be a pointer type");
2504 PointerOptions Options = PointerOptions::None;
2505 if (SubroutineTy->getFlags() & DINode::DIFlags::FlagLValueReference)
2506 Options = PointerOptions::LValueRefThisPointer;
2507 else if (SubroutineTy->getFlags() & DINode::DIFlags::FlagRValueReference)
2508 Options = PointerOptions::RValueRefThisPointer;
2510 // Check if we've already translated this type. If there is no ref qualifier
2511 // on the function then we look up this pointer type with no associated class
2512 // so that the TypeIndex for the this pointer can be shared with the type
2513 // index for other pointers to this class type. If there is a ref qualifier
2514 // then we lookup the pointer using the subroutine as the parent type.
2515 auto I = TypeIndices.find({PtrTy, SubroutineTy});
2516 if (I != TypeIndices.end())
2519 TypeLoweringScope S(*this);
2520 TypeIndex TI = lowerTypePointer(PtrTy, Options);
2521 return recordTypeIndexForDINode(PtrTy, TI, SubroutineTy);
2524 TypeIndex CodeViewDebug::getTypeIndexForReferenceTo(const DIType *Ty) {
2525 PointerRecord PR(getTypeIndex(Ty),
2526 getPointerSizeInBytes() == 8 ? PointerKind::Near64
2527 : PointerKind::Near32,
2528 PointerMode::LValueReference, PointerOptions::None,
2529 Ty->getSizeInBits() / 8);
2530 return TypeTable.writeLeafType(PR);
2533 TypeIndex CodeViewDebug::getCompleteTypeIndex(const DIType *Ty) {
2534 // The null DIType is the void type. Don't try to hash it.
2536 return TypeIndex::Void();
2538 // Look through typedefs when getting the complete type index. Call
2539 // getTypeIndex on the typdef to ensure that any UDTs are accumulated and are
2540 // emitted only once.
2541 if (Ty->getTag() == dwarf::DW_TAG_typedef)
2542 (void)getTypeIndex(Ty);
2543 while (Ty->getTag() == dwarf::DW_TAG_typedef)
2544 Ty = cast<DIDerivedType>(Ty)->getBaseType();
2546 // If this is a non-record type, the complete type index is the same as the
2547 // normal type index. Just call getTypeIndex.
2548 switch (Ty->getTag()) {
2549 case dwarf::DW_TAG_class_type:
2550 case dwarf::DW_TAG_structure_type:
2551 case dwarf::DW_TAG_union_type:
2554 return getTypeIndex(Ty);
2557 const auto *CTy = cast<DICompositeType>(Ty);
2559 TypeLoweringScope S(*this);
2561 // Make sure the forward declaration is emitted first. It's unclear if this
2562 // is necessary, but MSVC does it, and we should follow suit until we can show
2564 // We only emit a forward declaration for named types.
2565 if (!CTy->getName().empty() || !CTy->getIdentifier().empty()) {
2566 TypeIndex FwdDeclTI = getTypeIndex(CTy);
2568 // Just use the forward decl if we don't have complete type info. This
2569 // might happen if the frontend is using modules and expects the complete
2570 // definition to be emitted elsewhere.
2571 if (CTy->isForwardDecl())
2575 // Check if we've already translated the complete record type.
2576 // Insert the type with a null TypeIndex to signify that the type is currently
2578 auto InsertResult = CompleteTypeIndices.insert({CTy, TypeIndex()});
2579 if (!InsertResult.second)
2580 return InsertResult.first->second;
2583 switch (CTy->getTag()) {
2584 case dwarf::DW_TAG_class_type:
2585 case dwarf::DW_TAG_structure_type:
2586 TI = lowerCompleteTypeClass(CTy);
2588 case dwarf::DW_TAG_union_type:
2589 TI = lowerCompleteTypeUnion(CTy);
2592 llvm_unreachable("not a record");
2595 // Update the type index associated with this CompositeType. This cannot
2596 // use the 'InsertResult' iterator above because it is potentially
2597 // invalidated by map insertions which can occur while lowering the class
2599 CompleteTypeIndices[CTy] = TI;
2603 /// Emit all the deferred complete record types. Try to do this in FIFO order,
2604 /// and do this until fixpoint, as each complete record type typically
2606 /// many other record types.
2607 void CodeViewDebug::emitDeferredCompleteTypes() {
2608 SmallVector<const DICompositeType *, 4> TypesToEmit;
2609 while (!DeferredCompleteTypes.empty()) {
2610 std::swap(DeferredCompleteTypes, TypesToEmit);
2611 for (const DICompositeType *RecordTy : TypesToEmit)
2612 getCompleteTypeIndex(RecordTy);
2613 TypesToEmit.clear();
2617 void CodeViewDebug::emitLocalVariableList(const FunctionInfo &FI,
2618 ArrayRef<LocalVariable> Locals) {
2619 // Get the sorted list of parameters and emit them first.
2620 SmallVector<const LocalVariable *, 6> Params;
2621 for (const LocalVariable &L : Locals)
2622 if (L.DIVar->isParameter())
2623 Params.push_back(&L);
2624 llvm::sort(Params, [](const LocalVariable *L, const LocalVariable *R) {
2625 return L->DIVar->getArg() < R->DIVar->getArg();
2627 for (const LocalVariable *L : Params)
2628 emitLocalVariable(FI, *L);
2630 // Next emit all non-parameters in the order that we found them.
2631 for (const LocalVariable &L : Locals)
2632 if (!L.DIVar->isParameter())
2633 emitLocalVariable(FI, L);
2636 /// Only call this on endian-specific types like ulittle16_t and little32_t, or
2637 /// structs composed of them.
2638 template <typename T>
2639 static void copyBytesForDefRange(SmallString<20> &BytePrefix,
2640 SymbolKind SymKind, const T &DefRangeHeader) {
2641 BytePrefix.resize(2 + sizeof(T));
2642 ulittle16_t SymKindLE = ulittle16_t(SymKind);
2643 memcpy(&BytePrefix[0], &SymKindLE, 2);
2644 memcpy(&BytePrefix[2], &DefRangeHeader, sizeof(T));
2647 void CodeViewDebug::emitLocalVariable(const FunctionInfo &FI,
2648 const LocalVariable &Var) {
2649 // LocalSym record, see SymbolRecord.h for more info.
2650 MCSymbol *LocalEnd = beginSymbolRecord(SymbolKind::S_LOCAL);
2652 LocalSymFlags Flags = LocalSymFlags::None;
2653 if (Var.DIVar->isParameter())
2654 Flags |= LocalSymFlags::IsParameter;
2655 if (Var.DefRanges.empty())
2656 Flags |= LocalSymFlags::IsOptimizedOut;
2658 OS.AddComment("TypeIndex");
2659 TypeIndex TI = Var.UseReferenceType
2660 ? getTypeIndexForReferenceTo(Var.DIVar->getType())
2661 : getCompleteTypeIndex(Var.DIVar->getType());
2662 OS.EmitIntValue(TI.getIndex(), 4);
2663 OS.AddComment("Flags");
2664 OS.EmitIntValue(static_cast<uint16_t>(Flags), 2);
2665 // Truncate the name so we won't overflow the record length field.
2666 emitNullTerminatedSymbolName(OS, Var.DIVar->getName());
2667 endSymbolRecord(LocalEnd);
2669 // Calculate the on disk prefix of the appropriate def range record. The
2670 // records and on disk formats are described in SymbolRecords.h. BytePrefix
2671 // should be big enough to hold all forms without memory allocation.
2672 SmallString<20> BytePrefix;
2673 for (const LocalVarDefRange &DefRange : Var.DefRanges) {
2675 if (DefRange.InMemory) {
2676 int Offset = DefRange.DataOffset;
2677 unsigned Reg = DefRange.CVRegister;
2679 // 32-bit x86 call sequences often use PUSH instructions, which disrupt
2680 // ESP-relative offsets. Use the virtual frame pointer, VFRAME or $T0,
2681 // instead. In frames without stack realignment, $T0 will be the CFA.
2682 if (RegisterId(Reg) == RegisterId::ESP) {
2683 Reg = unsigned(RegisterId::VFRAME);
2684 Offset += FI.OffsetAdjustment;
2687 // If we can use the chosen frame pointer for the frame and this isn't a
2688 // sliced aggregate, use the smaller S_DEFRANGE_FRAMEPOINTER_REL record.
2689 // Otherwise, use S_DEFRANGE_REGISTER_REL.
2690 EncodedFramePtrReg EncFP = encodeFramePtrReg(RegisterId(Reg), TheCPU);
2691 if (!DefRange.IsSubfield && EncFP != EncodedFramePtrReg::None &&
2692 (bool(Flags & LocalSymFlags::IsParameter)
2693 ? (EncFP == FI.EncodedParamFramePtrReg)
2694 : (EncFP == FI.EncodedLocalFramePtrReg))) {
2695 little32_t FPOffset = little32_t(Offset);
2696 copyBytesForDefRange(BytePrefix, S_DEFRANGE_FRAMEPOINTER_REL, FPOffset);
2698 uint16_t RegRelFlags = 0;
2699 if (DefRange.IsSubfield) {
2700 RegRelFlags = DefRangeRegisterRelSym::IsSubfieldFlag |
2701 (DefRange.StructOffset
2702 << DefRangeRegisterRelSym::OffsetInParentShift);
2704 DefRangeRegisterRelSym::Header DRHdr;
2705 DRHdr.Register = Reg;
2706 DRHdr.Flags = RegRelFlags;
2707 DRHdr.BasePointerOffset = Offset;
2708 copyBytesForDefRange(BytePrefix, S_DEFRANGE_REGISTER_REL, DRHdr);
2711 assert(DefRange.DataOffset == 0 && "unexpected offset into register");
2712 if (DefRange.IsSubfield) {
2713 DefRangeSubfieldRegisterSym::Header DRHdr;
2714 DRHdr.Register = DefRange.CVRegister;
2715 DRHdr.MayHaveNoName = 0;
2716 DRHdr.OffsetInParent = DefRange.StructOffset;
2717 copyBytesForDefRange(BytePrefix, S_DEFRANGE_SUBFIELD_REGISTER, DRHdr);
2719 DefRangeRegisterSym::Header DRHdr;
2720 DRHdr.Register = DefRange.CVRegister;
2721 DRHdr.MayHaveNoName = 0;
2722 copyBytesForDefRange(BytePrefix, S_DEFRANGE_REGISTER, DRHdr);
2725 OS.EmitCVDefRangeDirective(DefRange.Ranges, BytePrefix);
2729 void CodeViewDebug::emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks,
2730 const FunctionInfo& FI) {
2731 for (LexicalBlock *Block : Blocks)
2732 emitLexicalBlock(*Block, FI);
2735 /// Emit an S_BLOCK32 and S_END record pair delimiting the contents of a
2736 /// lexical block scope.
2737 void CodeViewDebug::emitLexicalBlock(const LexicalBlock &Block,
2738 const FunctionInfo& FI) {
2739 MCSymbol *RecordEnd = beginSymbolRecord(SymbolKind::S_BLOCK32);
2740 OS.AddComment("PtrParent");
2741 OS.EmitIntValue(0, 4); // PtrParent
2742 OS.AddComment("PtrEnd");
2743 OS.EmitIntValue(0, 4); // PtrEnd
2744 OS.AddComment("Code size");
2745 OS.emitAbsoluteSymbolDiff(Block.End, Block.Begin, 4); // Code Size
2746 OS.AddComment("Function section relative address");
2747 OS.EmitCOFFSecRel32(Block.Begin, /*Offset=*/0); // Func Offset
2748 OS.AddComment("Function section index");
2749 OS.EmitCOFFSectionIndex(FI.Begin); // Func Symbol
2750 OS.AddComment("Lexical block name");
2751 emitNullTerminatedSymbolName(OS, Block.Name); // Name
2752 endSymbolRecord(RecordEnd);
2754 // Emit variables local to this lexical block.
2755 emitLocalVariableList(FI, Block.Locals);
2756 emitGlobalVariableList(Block.Globals);
2758 // Emit lexical blocks contained within this block.
2759 emitLexicalBlockList(Block.Children, FI);
2761 // Close the lexical block scope.
2762 emitEndSymbolRecord(SymbolKind::S_END);
2765 /// Convenience routine for collecting lexical block information for a list
2766 /// of lexical scopes.
2767 void CodeViewDebug::collectLexicalBlockInfo(
2768 SmallVectorImpl<LexicalScope *> &Scopes,
2769 SmallVectorImpl<LexicalBlock *> &Blocks,
2770 SmallVectorImpl<LocalVariable> &Locals,
2771 SmallVectorImpl<CVGlobalVariable> &Globals) {
2772 for (LexicalScope *Scope : Scopes)
2773 collectLexicalBlockInfo(*Scope, Blocks, Locals, Globals);
2776 /// Populate the lexical blocks and local variable lists of the parent with
2777 /// information about the specified lexical scope.
2778 void CodeViewDebug::collectLexicalBlockInfo(
2779 LexicalScope &Scope,
2780 SmallVectorImpl<LexicalBlock *> &ParentBlocks,
2781 SmallVectorImpl<LocalVariable> &ParentLocals,
2782 SmallVectorImpl<CVGlobalVariable> &ParentGlobals) {
2783 if (Scope.isAbstractScope())
2786 // Gather information about the lexical scope including local variables,
2787 // global variables, and address ranges.
2788 bool IgnoreScope = false;
2789 auto LI = ScopeVariables.find(&Scope);
2790 SmallVectorImpl<LocalVariable> *Locals =
2791 LI != ScopeVariables.end() ? &LI->second : nullptr;
2792 auto GI = ScopeGlobals.find(Scope.getScopeNode());
2793 SmallVectorImpl<CVGlobalVariable> *Globals =
2794 GI != ScopeGlobals.end() ? GI->second.get() : nullptr;
2795 const DILexicalBlock *DILB = dyn_cast<DILexicalBlock>(Scope.getScopeNode());
2796 const SmallVectorImpl<InsnRange> &Ranges = Scope.getRanges();
2798 // Ignore lexical scopes which do not contain variables.
2799 if (!Locals && !Globals)
2802 // Ignore lexical scopes which are not lexical blocks.
2806 // Ignore scopes which have too many address ranges to represent in the
2807 // current CodeView format or do not have a valid address range.
2809 // For lexical scopes with multiple address ranges you may be tempted to
2810 // construct a single range covering every instruction where the block is
2811 // live and everything in between. Unfortunately, Visual Studio only
2812 // displays variables from the first matching lexical block scope. If the
2813 // first lexical block contains exception handling code or cold code which
2814 // is moved to the bottom of the routine creating a single range covering
2815 // nearly the entire routine, then it will hide all other lexical blocks
2816 // and the variables they contain.
2817 if (Ranges.size() != 1 || !getLabelAfterInsn(Ranges.front().second))
2821 // This scope can be safely ignored and eliminating it will reduce the
2822 // size of the debug information. Be sure to collect any variable and scope
2823 // information from the this scope or any of its children and collapse them
2824 // into the parent scope.
2826 ParentLocals.append(Locals->begin(), Locals->end());
2828 ParentGlobals.append(Globals->begin(), Globals->end());
2829 collectLexicalBlockInfo(Scope.getChildren(),
2836 // Create a new CodeView lexical block for this lexical scope. If we've
2837 // seen this DILexicalBlock before then the scope tree is malformed and
2838 // we can handle this gracefully by not processing it a second time.
2839 auto BlockInsertion = CurFn->LexicalBlocks.insert({DILB, LexicalBlock()});
2840 if (!BlockInsertion.second)
2843 // Create a lexical block containing the variables and collect the the
2844 // lexical block information for the children.
2845 const InsnRange &Range = Ranges.front();
2846 assert(Range.first && Range.second);
2847 LexicalBlock &Block = BlockInsertion.first->second;
2848 Block.Begin = getLabelBeforeInsn(Range.first);
2849 Block.End = getLabelAfterInsn(Range.second);
2850 assert(Block.Begin && "missing label for scope begin");
2851 assert(Block.End && "missing label for scope end");
2852 Block.Name = DILB->getName();
2854 Block.Locals = std::move(*Locals);
2856 Block.Globals = std::move(*Globals);
2857 ParentBlocks.push_back(&Block);
2858 collectLexicalBlockInfo(Scope.getChildren(),
2864 void CodeViewDebug::endFunctionImpl(const MachineFunction *MF) {
2865 const Function &GV = MF->getFunction();
2866 assert(FnDebugInfo.count(&GV));
2867 assert(CurFn == FnDebugInfo[&GV].get());
2869 collectVariableInfo(GV.getSubprogram());
2871 // Build the lexical block structure to emit for this routine.
2872 if (LexicalScope *CFS = LScopes.getCurrentFunctionScope())
2873 collectLexicalBlockInfo(*CFS,
2878 // Clear the scope and variable information from the map which will not be
2879 // valid after we have finished processing this routine. This also prepares
2880 // the map for the subsequent routine.
2881 ScopeVariables.clear();
2883 // Don't emit anything if we don't have any line tables.
2884 // Thunks are compiler-generated and probably won't have source correlation.
2885 if (!CurFn->HaveLineInfo && !GV.getSubprogram()->isThunk()) {
2886 FnDebugInfo.erase(&GV);
2891 CurFn->Annotations = MF->getCodeViewAnnotations();
2892 CurFn->HeapAllocSites = MF->getCodeViewHeapAllocSites();
2894 CurFn->End = Asm->getFunctionEnd();
2899 void CodeViewDebug::beginInstruction(const MachineInstr *MI) {
2900 DebugHandlerBase::beginInstruction(MI);
2902 // Ignore DBG_VALUE and DBG_LABEL locations and function prologue.
2903 if (!Asm || !CurFn || MI->isDebugInstr() ||
2904 MI->getFlag(MachineInstr::FrameSetup))
2907 // If the first instruction of a new MBB has no location, find the first
2908 // instruction with a location and use that.
2909 DebugLoc DL = MI->getDebugLoc();
2910 if (!DL && MI->getParent() != PrevInstBB) {
2911 for (const auto &NextMI : *MI->getParent()) {
2912 if (NextMI.isDebugInstr())
2914 DL = NextMI.getDebugLoc();
2919 PrevInstBB = MI->getParent();
2921 // If we still don't have a debug location, don't record a location.
2925 maybeRecordLocation(DL, Asm->MF);
2928 MCSymbol *CodeViewDebug::beginCVSubsection(DebugSubsectionKind Kind) {
2929 MCSymbol *BeginLabel = MMI->getContext().createTempSymbol(),
2930 *EndLabel = MMI->getContext().createTempSymbol();
2931 OS.EmitIntValue(unsigned(Kind), 4);
2932 OS.AddComment("Subsection size");
2933 OS.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 4);
2934 OS.EmitLabel(BeginLabel);
2938 void CodeViewDebug::endCVSubsection(MCSymbol *EndLabel) {
2939 OS.EmitLabel(EndLabel);
2940 // Every subsection must be aligned to a 4-byte boundary.
2941 OS.EmitValueToAlignment(4);
2944 static StringRef getSymbolName(SymbolKind SymKind) {
2945 for (const EnumEntry<SymbolKind> &EE : getSymbolTypeNames())
2946 if (EE.Value == SymKind)
2951 MCSymbol *CodeViewDebug::beginSymbolRecord(SymbolKind SymKind) {
2952 MCSymbol *BeginLabel = MMI->getContext().createTempSymbol(),
2953 *EndLabel = MMI->getContext().createTempSymbol();
2954 OS.AddComment("Record length");
2955 OS.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 2);
2956 OS.EmitLabel(BeginLabel);
2957 if (OS.isVerboseAsm())
2958 OS.AddComment("Record kind: " + getSymbolName(SymKind));
2959 OS.EmitIntValue(unsigned(SymKind), 2);
2963 void CodeViewDebug::endSymbolRecord(MCSymbol *SymEnd) {
2964 // MSVC does not pad out symbol records to four bytes, but LLVM does to avoid
2965 // an extra copy of every symbol record in LLD. This increases object file
2966 // size by less than 1% in the clang build, and is compatible with the Visual
2968 OS.EmitValueToAlignment(4);
2969 OS.EmitLabel(SymEnd);
2972 void CodeViewDebug::emitEndSymbolRecord(SymbolKind EndKind) {
2973 OS.AddComment("Record length");
2974 OS.EmitIntValue(2, 2);
2975 if (OS.isVerboseAsm())
2976 OS.AddComment("Record kind: " + getSymbolName(EndKind));
2977 OS.EmitIntValue(unsigned(EndKind), 2); // Record Kind
2980 void CodeViewDebug::emitDebugInfoForUDTs(
2981 ArrayRef<std::pair<std::string, const DIType *>> UDTs) {
2982 for (const auto &UDT : UDTs) {
2983 const DIType *T = UDT.second;
2984 assert(shouldEmitUdt(T));
2986 MCSymbol *UDTRecordEnd = beginSymbolRecord(SymbolKind::S_UDT);
2987 OS.AddComment("Type");
2988 OS.EmitIntValue(getCompleteTypeIndex(T).getIndex(), 4);
2989 emitNullTerminatedSymbolName(OS, UDT.first);
2990 endSymbolRecord(UDTRecordEnd);
2994 void CodeViewDebug::collectGlobalVariableInfo() {
2995 DenseMap<const DIGlobalVariableExpression *, const GlobalVariable *>
2997 for (const GlobalVariable &GV : MMI->getModule()->globals()) {
2998 SmallVector<DIGlobalVariableExpression *, 1> GVEs;
2999 GV.getDebugInfo(GVEs);
3000 for (const auto *GVE : GVEs)
3001 GlobalMap[GVE] = &GV;
3004 NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu");
3005 for (const MDNode *Node : CUs->operands()) {
3006 const auto *CU = cast<DICompileUnit>(Node);
3007 for (const auto *GVE : CU->getGlobalVariables()) {
3008 const DIGlobalVariable *DIGV = GVE->getVariable();
3009 const DIExpression *DIE = GVE->getExpression();
3011 // Emit constant global variables in a global symbol section.
3012 if (GlobalMap.count(GVE) == 0 && DIE->isConstant()) {
3013 CVGlobalVariable CVGV = {DIGV, DIE};
3014 GlobalVariables.emplace_back(std::move(CVGV));
3017 const auto *GV = GlobalMap.lookup(GVE);
3018 if (!GV || GV->isDeclarationForLinker())
3021 DIScope *Scope = DIGV->getScope();
3022 SmallVector<CVGlobalVariable, 1> *VariableList;
3023 if (Scope && isa<DILocalScope>(Scope)) {
3024 // Locate a global variable list for this scope, creating one if
3026 auto Insertion = ScopeGlobals.insert(
3027 {Scope, std::unique_ptr<GlobalVariableList>()});
3028 if (Insertion.second)
3029 Insertion.first->second = llvm::make_unique<GlobalVariableList>();
3030 VariableList = Insertion.first->second.get();
3031 } else if (GV->hasComdat())
3032 // Emit this global variable into a COMDAT section.
3033 VariableList = &ComdatVariables;
3035 // Emit this global variable in a single global symbol section.
3036 VariableList = &GlobalVariables;
3037 CVGlobalVariable CVGV = {DIGV, GV};
3038 VariableList->emplace_back(std::move(CVGV));
3043 void CodeViewDebug::emitDebugInfoForGlobals() {
3044 // First, emit all globals that are not in a comdat in a single symbol
3045 // substream. MSVC doesn't like it if the substream is empty, so only open
3046 // it if we have at least one global to emit.
3047 switchToDebugSectionForSymbol(nullptr);
3048 if (!GlobalVariables.empty()) {
3049 OS.AddComment("Symbol subsection for globals");
3050 MCSymbol *EndLabel = beginCVSubsection(DebugSubsectionKind::Symbols);
3051 emitGlobalVariableList(GlobalVariables);
3052 endCVSubsection(EndLabel);
3055 // Second, emit each global that is in a comdat into its own .debug$S
3056 // section along with its own symbol substream.
3057 for (const CVGlobalVariable &CVGV : ComdatVariables) {
3058 const GlobalVariable *GV = CVGV.GVInfo.get<const GlobalVariable *>();
3059 MCSymbol *GVSym = Asm->getSymbol(GV);
3060 OS.AddComment("Symbol subsection for " +
3061 Twine(GlobalValue::dropLLVMManglingEscape(GV->getName())));
3062 switchToDebugSectionForSymbol(GVSym);
3063 MCSymbol *EndLabel = beginCVSubsection(DebugSubsectionKind::Symbols);
3064 // FIXME: emitDebugInfoForGlobal() doesn't handle DIExpressions.
3065 emitDebugInfoForGlobal(CVGV);
3066 endCVSubsection(EndLabel);
3070 void CodeViewDebug::emitDebugInfoForRetainedTypes() {
3071 NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu");
3072 for (const MDNode *Node : CUs->operands()) {
3073 for (auto *Ty : cast<DICompileUnit>(Node)->getRetainedTypes()) {
3074 if (DIType *RT = dyn_cast<DIType>(Ty)) {
3076 // FIXME: Add to global/local DTU list.
3082 // Emit each global variable in the specified array.
3083 void CodeViewDebug::emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals) {
3084 for (const CVGlobalVariable &CVGV : Globals) {
3085 // FIXME: emitDebugInfoForGlobal() doesn't handle DIExpressions.
3086 emitDebugInfoForGlobal(CVGV);
3090 void CodeViewDebug::emitDebugInfoForGlobal(const CVGlobalVariable &CVGV) {
3091 const DIGlobalVariable *DIGV = CVGV.DIGV;
3092 if (const GlobalVariable *GV =
3093 CVGV.GVInfo.dyn_cast<const GlobalVariable *>()) {
3094 // DataSym record, see SymbolRecord.h for more info. Thread local data
3095 // happens to have the same format as global data.
3096 MCSymbol *GVSym = Asm->getSymbol(GV);
3097 SymbolKind DataSym = GV->isThreadLocal()
3098 ? (DIGV->isLocalToUnit() ? SymbolKind::S_LTHREAD32
3099 : SymbolKind::S_GTHREAD32)
3100 : (DIGV->isLocalToUnit() ? SymbolKind::S_LDATA32
3101 : SymbolKind::S_GDATA32);
3102 MCSymbol *DataEnd = beginSymbolRecord(DataSym);
3103 OS.AddComment("Type");
3104 OS.EmitIntValue(getCompleteTypeIndex(DIGV->getType()).getIndex(), 4);
3105 OS.AddComment("DataOffset");
3106 OS.EmitCOFFSecRel32(GVSym, /*Offset=*/0);
3107 OS.AddComment("Segment");
3108 OS.EmitCOFFSectionIndex(GVSym);
3109 OS.AddComment("Name");
3110 const unsigned LengthOfDataRecord = 12;
3111 emitNullTerminatedSymbolName(OS, DIGV->getName(), LengthOfDataRecord);
3112 endSymbolRecord(DataEnd);
3114 // FIXME: Currently this only emits the global variables in the IR metadata.
3115 // This should also emit enums and static data members.
3116 const DIExpression *DIE = CVGV.GVInfo.get<const DIExpression *>();
3117 assert(DIE->isConstant() &&
3118 "Global constant variables must contain a constant expression.");
3119 uint64_t Val = DIE->getElement(1);
3121 MCSymbol *SConstantEnd = beginSymbolRecord(SymbolKind::S_CONSTANT);
3122 OS.AddComment("Type");
3123 OS.EmitIntValue(getTypeIndex(DIGV->getType()).getIndex(), 4);
3124 OS.AddComment("Value");
3126 // Encoded integers shouldn't need more than 10 bytes.
3128 BinaryStreamWriter Writer(data, llvm::support::endianness::little);
3129 CodeViewRecordIO IO(Writer);
3130 cantFail(IO.mapEncodedInteger(Val));
3131 StringRef SRef((char *)data, Writer.getOffset());
3132 OS.EmitBinaryData(SRef);
3134 OS.AddComment("Name");
3135 const DIScope *Scope = DIGV->getScope();
3136 // For static data members, get the scope from the declaration.
3137 if (const auto *MemberDecl = dyn_cast_or_null<DIDerivedType>(
3138 DIGV->getRawStaticDataMemberDeclaration()))
3139 Scope = MemberDecl->getScope();
3140 emitNullTerminatedSymbolName(OS,
3141 getFullyQualifiedName(Scope, DIGV->getName()));
3142 endSymbolRecord(SConstantEnd);