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Diffstat (limited to 'contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp')
| -rw-r--r-- | contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp | 3444 |
1 files changed, 3444 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp new file mode 100644 index 000000000000..8161de57b58e --- /dev/null +++ b/contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp @@ -0,0 +1,3444 @@ +//===- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp ----------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file contains support for writing Microsoft CodeView debug info. +// +//===----------------------------------------------------------------------===// + +#include "CodeViewDebug.h" +#include "llvm/ADT/APSInt.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/TinyPtrVector.h" +#include "llvm/ADT/Twine.h" +#include "llvm/BinaryFormat/COFF.h" +#include "llvm/BinaryFormat/Dwarf.h" +#include "llvm/CodeGen/AsmPrinter.h" +#include "llvm/CodeGen/LexicalScopes.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/CodeGen/MachineModuleInfo.h" +#include "llvm/CodeGen/TargetFrameLowering.h" +#include "llvm/CodeGen/TargetRegisterInfo.h" +#include "llvm/CodeGen/TargetSubtargetInfo.h" +#include "llvm/Config/llvm-config.h" +#include "llvm/DebugInfo/CodeView/CVTypeVisitor.h" +#include "llvm/DebugInfo/CodeView/CodeViewRecordIO.h" +#include "llvm/DebugInfo/CodeView/ContinuationRecordBuilder.h" +#include "llvm/DebugInfo/CodeView/DebugInlineeLinesSubsection.h" +#include "llvm/DebugInfo/CodeView/EnumTables.h" +#include "llvm/DebugInfo/CodeView/Line.h" +#include "llvm/DebugInfo/CodeView/SymbolRecord.h" +#include "llvm/DebugInfo/CodeView/TypeRecord.h" +#include "llvm/DebugInfo/CodeView/TypeTableCollection.h" +#include "llvm/DebugInfo/CodeView/TypeVisitorCallbackPipeline.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DebugInfoMetadata.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/GlobalValue.h" +#include "llvm/IR/GlobalVariable.h" +#include "llvm/IR/Metadata.h" +#include "llvm/IR/Module.h" +#include "llvm/MC/MCAsmInfo.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCSectionCOFF.h" +#include "llvm/MC/MCStreamer.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/Support/BinaryStreamWriter.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/Endian.h" +#include "llvm/Support/Error.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/FormatVariadic.h" +#include "llvm/Support/Path.h" +#include "llvm/Support/Program.h" +#include "llvm/Support/SMLoc.h" +#include "llvm/Support/ScopedPrinter.h" +#include "llvm/Target/TargetLoweringObjectFile.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/TargetParser/Triple.h" +#include <algorithm> +#include <cassert> +#include <cctype> +#include <cstddef> +#include <iterator> +#include <limits> + +using namespace llvm; +using namespace llvm::codeview; + +namespace { +class CVMCAdapter : public CodeViewRecordStreamer { +public: + CVMCAdapter(MCStreamer &OS, TypeCollection &TypeTable) + : OS(&OS), TypeTable(TypeTable) {} + + void emitBytes(StringRef Data) override { OS->emitBytes(Data); } + + void emitIntValue(uint64_t Value, unsigned Size) override { + OS->emitIntValueInHex(Value, Size); + } + + void emitBinaryData(StringRef Data) override { OS->emitBinaryData(Data); } + + void AddComment(const Twine &T) override { OS->AddComment(T); } + + void AddRawComment(const Twine &T) override { OS->emitRawComment(T); } + + bool isVerboseAsm() override { return OS->isVerboseAsm(); } + + std::string getTypeName(TypeIndex TI) override { + std::string TypeName; + if (!TI.isNoneType()) { + if (TI.isSimple()) + TypeName = std::string(TypeIndex::simpleTypeName(TI)); + else + TypeName = std::string(TypeTable.getTypeName(TI)); + } + return TypeName; + } + +private: + MCStreamer *OS = nullptr; + TypeCollection &TypeTable; +}; +} // namespace + +static CPUType mapArchToCVCPUType(Triple::ArchType Type) { + switch (Type) { + case Triple::ArchType::x86: + return CPUType::Pentium3; + case Triple::ArchType::x86_64: + return CPUType::X64; + case Triple::ArchType::thumb: + // LLVM currently doesn't support Windows CE and so thumb + // here is indiscriminately mapped to ARMNT specifically. + return CPUType::ARMNT; + case Triple::ArchType::aarch64: + return CPUType::ARM64; + default: + report_fatal_error("target architecture doesn't map to a CodeView CPUType"); + } +} + +CodeViewDebug::CodeViewDebug(AsmPrinter *AP) + : DebugHandlerBase(AP), OS(*Asm->OutStreamer), TypeTable(Allocator) {} + +StringRef CodeViewDebug::getFullFilepath(const DIFile *File) { + std::string &Filepath = FileToFilepathMap[File]; + if (!Filepath.empty()) + return Filepath; + + StringRef Dir = File->getDirectory(), Filename = File->getFilename(); + + // If this is a Unix-style path, just use it as is. Don't try to canonicalize + // it textually because one of the path components could be a symlink. + if (Dir.startswith("/") || Filename.startswith("/")) { + if (llvm::sys::path::is_absolute(Filename, llvm::sys::path::Style::posix)) + return Filename; + Filepath = std::string(Dir); + if (Dir.back() != '/') + Filepath += '/'; + Filepath += Filename; + return Filepath; + } + + // Clang emits directory and relative filename info into the IR, but CodeView + // operates on full paths. We could change Clang to emit full paths too, but + // that would increase the IR size and probably not needed for other users. + // For now, just concatenate and canonicalize the path here. + if (Filename.find(':') == 1) + Filepath = std::string(Filename); + else + Filepath = (Dir + "\\" + Filename).str(); + + // Canonicalize the path. We have to do it textually because we may no longer + // have access the file in the filesystem. + // First, replace all slashes with backslashes. + std::replace(Filepath.begin(), Filepath.end(), '/', '\\'); + + // Remove all "\.\" with "\". + size_t Cursor = 0; + while ((Cursor = Filepath.find("\\.\\", Cursor)) != std::string::npos) + Filepath.erase(Cursor, 2); + + // Replace all "\XXX\..\" with "\". Don't try too hard though as the original + // path should be well-formatted, e.g. start with a drive letter, etc. + Cursor = 0; + while ((Cursor = Filepath.find("\\..\\", Cursor)) != std::string::npos) { + // Something's wrong if the path starts with "\..\", abort. + if (Cursor == 0) + break; + + size_t PrevSlash = Filepath.rfind('\\', Cursor - 1); + if (PrevSlash == std::string::npos) + // Something's wrong, abort. + break; + + Filepath.erase(PrevSlash, Cursor + 3 - PrevSlash); + // The next ".." might be following the one we've just erased. + Cursor = PrevSlash; + } + + // Remove all duplicate backslashes. + Cursor = 0; + while ((Cursor = Filepath.find("\\\\", Cursor)) != std::string::npos) + Filepath.erase(Cursor, 1); + + return Filepath; +} + +unsigned CodeViewDebug::maybeRecordFile(const DIFile *F) { + StringRef FullPath = getFullFilepath(F); + unsigned NextId = FileIdMap.size() + 1; + auto Insertion = FileIdMap.insert(std::make_pair(FullPath, NextId)); + if (Insertion.second) { + // We have to compute the full filepath and emit a .cv_file directive. + ArrayRef<uint8_t> ChecksumAsBytes; + FileChecksumKind CSKind = FileChecksumKind::None; + if (F->getChecksum()) { + std::string Checksum = fromHex(F->getChecksum()->Value); + void *CKMem = OS.getContext().allocate(Checksum.size(), 1); + memcpy(CKMem, Checksum.data(), Checksum.size()); + ChecksumAsBytes = ArrayRef<uint8_t>( + reinterpret_cast<const uint8_t *>(CKMem), Checksum.size()); + switch (F->getChecksum()->Kind) { + case DIFile::CSK_MD5: + CSKind = FileChecksumKind::MD5; + break; + case DIFile::CSK_SHA1: + CSKind = FileChecksumKind::SHA1; + break; + case DIFile::CSK_SHA256: + CSKind = FileChecksumKind::SHA256; + break; + } + } + bool Success = OS.emitCVFileDirective(NextId, FullPath, ChecksumAsBytes, + static_cast<unsigned>(CSKind)); + (void)Success; + assert(Success && ".cv_file directive failed"); + } + return Insertion.first->second; +} + +CodeViewDebug::InlineSite & +CodeViewDebug::getInlineSite(const DILocation *InlinedAt, + const DISubprogram *Inlinee) { + auto SiteInsertion = CurFn->InlineSites.insert({InlinedAt, InlineSite()}); + InlineSite *Site = &SiteInsertion.first->second; + if (SiteInsertion.second) { + unsigned ParentFuncId = CurFn->FuncId; + if (const DILocation *OuterIA = InlinedAt->getInlinedAt()) + ParentFuncId = + getInlineSite(OuterIA, InlinedAt->getScope()->getSubprogram()) + .SiteFuncId; + + Site->SiteFuncId = NextFuncId++; + OS.emitCVInlineSiteIdDirective( + Site->SiteFuncId, ParentFuncId, maybeRecordFile(InlinedAt->getFile()), + InlinedAt->getLine(), InlinedAt->getColumn(), SMLoc()); + Site->Inlinee = Inlinee; + InlinedSubprograms.insert(Inlinee); + getFuncIdForSubprogram(Inlinee); + } + return *Site; +} + +static StringRef getPrettyScopeName(const DIScope *Scope) { + StringRef ScopeName = Scope->getName(); + if (!ScopeName.empty()) + return ScopeName; + + switch (Scope->getTag()) { + case dwarf::DW_TAG_enumeration_type: + case dwarf::DW_TAG_class_type: + case dwarf::DW_TAG_structure_type: + case dwarf::DW_TAG_union_type: + return "<unnamed-tag>"; + case dwarf::DW_TAG_namespace: + return "`anonymous namespace'"; + default: + return StringRef(); + } +} + +const DISubprogram *CodeViewDebug::collectParentScopeNames( + const DIScope *Scope, SmallVectorImpl<StringRef> &QualifiedNameComponents) { + const DISubprogram *ClosestSubprogram = nullptr; + while (Scope != nullptr) { + if (ClosestSubprogram == nullptr) + ClosestSubprogram = dyn_cast<DISubprogram>(Scope); + + // If a type appears in a scope chain, make sure it gets emitted. The + // frontend will be responsible for deciding if this should be a forward + // declaration or a complete type. + if (const auto *Ty = dyn_cast<DICompositeType>(Scope)) + DeferredCompleteTypes.push_back(Ty); + + StringRef ScopeName = getPrettyScopeName(Scope); + if (!ScopeName.empty()) + QualifiedNameComponents.push_back(ScopeName); + Scope = Scope->getScope(); + } + return ClosestSubprogram; +} + +static std::string formatNestedName(ArrayRef<StringRef> QualifiedNameComponents, + StringRef TypeName) { + std::string FullyQualifiedName; + for (StringRef QualifiedNameComponent : + llvm::reverse(QualifiedNameComponents)) { + FullyQualifiedName.append(std::string(QualifiedNameComponent)); + FullyQualifiedName.append("::"); + } + FullyQualifiedName.append(std::string(TypeName)); + return FullyQualifiedName; +} + +struct CodeViewDebug::TypeLoweringScope { + TypeLoweringScope(CodeViewDebug &CVD) : CVD(CVD) { ++CVD.TypeEmissionLevel; } + ~TypeLoweringScope() { + // Don't decrement TypeEmissionLevel until after emitting deferred types, so + // inner TypeLoweringScopes don't attempt to emit deferred types. + if (CVD.TypeEmissionLevel == 1) + CVD.emitDeferredCompleteTypes(); + --CVD.TypeEmissionLevel; + } + CodeViewDebug &CVD; +}; + +std::string CodeViewDebug::getFullyQualifiedName(const DIScope *Scope, + StringRef Name) { + // Ensure types in the scope chain are emitted as soon as possible. + // This can create otherwise a situation where S_UDTs are emitted while + // looping in emitDebugInfoForUDTs. + TypeLoweringScope S(*this); + SmallVector<StringRef, 5> QualifiedNameComponents; + collectParentScopeNames(Scope, QualifiedNameComponents); + return formatNestedName(QualifiedNameComponents, Name); +} + +std::string CodeViewDebug::getFullyQualifiedName(const DIScope *Ty) { + const DIScope *Scope = Ty->getScope(); + return getFullyQualifiedName(Scope, getPrettyScopeName(Ty)); +} + +TypeIndex CodeViewDebug::getScopeIndex(const DIScope *Scope) { + // No scope means global scope and that uses the zero index. + // + // We also use zero index when the scope is a DISubprogram + // to suppress the emission of LF_STRING_ID for the function, + // which can trigger a link-time error with the linker in + // VS2019 version 16.11.2 or newer. + // Note, however, skipping the debug info emission for the DISubprogram + // is a temporary fix. The root issue here is that we need to figure out + // the proper way to encode a function nested in another function + // (as introduced by the Fortran 'contains' keyword) in CodeView. + if (!Scope || isa<DIFile>(Scope) || isa<DISubprogram>(Scope)) + return TypeIndex(); + + assert(!isa<DIType>(Scope) && "shouldn't make a namespace scope for a type"); + + // Check if we've already translated this scope. + auto I = TypeIndices.find({Scope, nullptr}); + if (I != TypeIndices.end()) + return I->second; + + // Build the fully qualified name of the scope. + std::string ScopeName = getFullyQualifiedName(Scope); + StringIdRecord SID(TypeIndex(), ScopeName); + auto TI = TypeTable.writeLeafType(SID); + return recordTypeIndexForDINode(Scope, TI); +} + +static StringRef removeTemplateArgs(StringRef Name) { + // Remove template args from the display name. Assume that the template args + // are the last thing in the name. + if (Name.empty() || Name.back() != '>') + return Name; + + int OpenBrackets = 0; + for (int i = Name.size() - 1; i >= 0; --i) { + if (Name[i] == '>') + ++OpenBrackets; + else if (Name[i] == '<') { + --OpenBrackets; + if (OpenBrackets == 0) + return Name.substr(0, i); + } + } + return Name; +} + +TypeIndex CodeViewDebug::getFuncIdForSubprogram(const DISubprogram *SP) { + assert(SP); + + // Check if we've already translated this subprogram. + auto I = TypeIndices.find({SP, nullptr}); + if (I != TypeIndices.end()) + return I->second; + + // The display name includes function template arguments. Drop them to match + // MSVC. We need to have the template arguments in the DISubprogram name + // because they are used in other symbol records, such as S_GPROC32_IDs. + StringRef DisplayName = removeTemplateArgs(SP->getName()); + + const DIScope *Scope = SP->getScope(); + TypeIndex TI; + if (const auto *Class = dyn_cast_or_null<DICompositeType>(Scope)) { + // If the scope is a DICompositeType, then this must be a method. Member + // function types take some special handling, and require access to the + // subprogram. + TypeIndex ClassType = getTypeIndex(Class); + MemberFuncIdRecord MFuncId(ClassType, getMemberFunctionType(SP, Class), + DisplayName); + TI = TypeTable.writeLeafType(MFuncId); + } else { + // Otherwise, this must be a free function. + TypeIndex ParentScope = getScopeIndex(Scope); + FuncIdRecord FuncId(ParentScope, getTypeIndex(SP->getType()), DisplayName); + TI = TypeTable.writeLeafType(FuncId); + } + + return recordTypeIndexForDINode(SP, TI); +} + +static bool isNonTrivial(const DICompositeType *DCTy) { + return ((DCTy->getFlags() & DINode::FlagNonTrivial) == DINode::FlagNonTrivial); +} + +static FunctionOptions +getFunctionOptions(const DISubroutineType *Ty, + const DICompositeType *ClassTy = nullptr, + StringRef SPName = StringRef("")) { + FunctionOptions FO = FunctionOptions::None; + const DIType *ReturnTy = nullptr; + if (auto TypeArray = Ty->getTypeArray()) { + if (TypeArray.size()) + ReturnTy = TypeArray[0]; + } + + // Add CxxReturnUdt option to functions that return nontrivial record types + // or methods that return record types. + if (auto *ReturnDCTy = dyn_cast_or_null<DICompositeType>(ReturnTy)) + if (isNonTrivial(ReturnDCTy) || ClassTy) + FO |= FunctionOptions::CxxReturnUdt; + + // DISubroutineType is unnamed. Use DISubprogram's i.e. SPName in comparison. + if (ClassTy && isNonTrivial(ClassTy) && SPName == ClassTy->getName()) { + FO |= FunctionOptions::Constructor; + + // TODO: put the FunctionOptions::ConstructorWithVirtualBases flag. + + } + return FO; +} + +TypeIndex CodeViewDebug::getMemberFunctionType(const DISubprogram *SP, + const DICompositeType *Class) { + // Always use the method declaration as the key for the function type. The + // method declaration contains the this adjustment. + if (SP->getDeclaration()) + SP = SP->getDeclaration(); + assert(!SP->getDeclaration() && "should use declaration as key"); + + // Key the MemberFunctionRecord into the map as {SP, Class}. It won't collide + // with the MemberFuncIdRecord, which is keyed in as {SP, nullptr}. + auto I = TypeIndices.find({SP, Class}); + if (I != TypeIndices.end()) + return I->second; + + // Make sure complete type info for the class is emitted *after* the member + // function type, as the complete class type is likely to reference this + // member function type. + TypeLoweringScope S(*this); + const bool IsStaticMethod = (SP->getFlags() & DINode::FlagStaticMember) != 0; + + FunctionOptions FO = getFunctionOptions(SP->getType(), Class, SP->getName()); + TypeIndex TI = lowerTypeMemberFunction( + SP->getType(), Class, SP->getThisAdjustment(), IsStaticMethod, FO); + return recordTypeIndexForDINode(SP, TI, Class); +} + +TypeIndex CodeViewDebug::recordTypeIndexForDINode(const DINode *Node, + TypeIndex TI, + const DIType *ClassTy) { + auto InsertResult = TypeIndices.insert({{Node, ClassTy}, TI}); + (void)InsertResult; + assert(InsertResult.second && "DINode was already assigned a type index"); + return TI; +} + +unsigned CodeViewDebug::getPointerSizeInBytes() { + return MMI->getModule()->getDataLayout().getPointerSizeInBits() / 8; +} + +void CodeViewDebug::recordLocalVariable(LocalVariable &&Var, + const LexicalScope *LS) { + if (const DILocation *InlinedAt = LS->getInlinedAt()) { + // This variable was inlined. Associate it with the InlineSite. + const DISubprogram *Inlinee = Var.DIVar->getScope()->getSubprogram(); + InlineSite &Site = getInlineSite(InlinedAt, Inlinee); + Site.InlinedLocals.emplace_back(std::move(Var)); + } else { + // This variable goes into the corresponding lexical scope. + ScopeVariables[LS].emplace_back(std::move(Var)); + } +} + +static void addLocIfNotPresent(SmallVectorImpl<const DILocation *> &Locs, + const DILocation *Loc) { + if (!llvm::is_contained(Locs, Loc)) + Locs.push_back(Loc); +} + +void CodeViewDebug::maybeRecordLocation(const DebugLoc &DL, + const MachineFunction *MF) { + // Skip this instruction if it has the same location as the previous one. + if (!DL || DL == PrevInstLoc) + return; + + const DIScope *Scope = DL->getScope(); + if (!Scope) + return; + + // Skip this line if it is longer than the maximum we can record. + LineInfo LI(DL.getLine(), DL.getLine(), /*IsStatement=*/true); + if (LI.getStartLine() != DL.getLine() || LI.isAlwaysStepInto() || + LI.isNeverStepInto()) + return; + + ColumnInfo CI(DL.getCol(), /*EndColumn=*/0); + if (CI.getStartColumn() != DL.getCol()) + return; + + if (!CurFn->HaveLineInfo) + CurFn->HaveLineInfo = true; + unsigned FileId = 0; + if (PrevInstLoc.get() && PrevInstLoc->getFile() == DL->getFile()) + FileId = CurFn->LastFileId; + else + FileId = CurFn->LastFileId = maybeRecordFile(DL->getFile()); + PrevInstLoc = DL; + + unsigned FuncId = CurFn->FuncId; + if (const DILocation *SiteLoc = DL->getInlinedAt()) { + const DILocation *Loc = DL.get(); + + // If this location was actually inlined from somewhere else, give it the ID + // of the inline call site. + FuncId = + getInlineSite(SiteLoc, Loc->getScope()->getSubprogram()).SiteFuncId; + + // Ensure we have links in the tree of inline call sites. + bool FirstLoc = true; + while ((SiteLoc = Loc->getInlinedAt())) { + InlineSite &Site = + getInlineSite(SiteLoc, Loc->getScope()->getSubprogram()); + if (!FirstLoc) + addLocIfNotPresent(Site.ChildSites, Loc); + FirstLoc = false; + Loc = SiteLoc; + } + addLocIfNotPresent(CurFn->ChildSites, Loc); + } + + OS.emitCVLocDirective(FuncId, FileId, DL.getLine(), DL.getCol(), + /*PrologueEnd=*/false, /*IsStmt=*/false, + DL->getFilename(), SMLoc()); +} + +void CodeViewDebug::emitCodeViewMagicVersion() { + OS.emitValueToAlignment(Align(4)); + OS.AddComment("Debug section magic"); + OS.emitInt32(COFF::DEBUG_SECTION_MAGIC); +} + +static SourceLanguage MapDWLangToCVLang(unsigned DWLang) { + switch (DWLang) { + case dwarf::DW_LANG_C: + case dwarf::DW_LANG_C89: + case dwarf::DW_LANG_C99: + case dwarf::DW_LANG_C11: + return SourceLanguage::C; + case dwarf::DW_LANG_C_plus_plus: + case dwarf::DW_LANG_C_plus_plus_03: + case dwarf::DW_LANG_C_plus_plus_11: + case dwarf::DW_LANG_C_plus_plus_14: + return SourceLanguage::Cpp; + case dwarf::DW_LANG_Fortran77: + case dwarf::DW_LANG_Fortran90: + case dwarf::DW_LANG_Fortran95: + case dwarf::DW_LANG_Fortran03: + case dwarf::DW_LANG_Fortran08: + return SourceLanguage::Fortran; + case dwarf::DW_LANG_Pascal83: + return SourceLanguage::Pascal; + case dwarf::DW_LANG_Cobol74: + case dwarf::DW_LANG_Cobol85: + return SourceLanguage::Cobol; + case dwarf::DW_LANG_Java: + return SourceLanguage::Java; + case dwarf::DW_LANG_D: + return SourceLanguage::D; + case dwarf::DW_LANG_Swift: + return SourceLanguage::Swift; + case dwarf::DW_LANG_Rust: + return SourceLanguage::Rust; + case dwarf::DW_LANG_ObjC: + return SourceLanguage::ObjC; + case dwarf::DW_LANG_ObjC_plus_plus: + return SourceLanguage::ObjCpp; + default: + // There's no CodeView representation for this language, and CV doesn't + // have an "unknown" option for the language field, so we'll use MASM, + // as it's very low level. + return SourceLanguage::Masm; + } +} + +void CodeViewDebug::beginModule(Module *M) { + // If module doesn't have named metadata anchors or COFF debug section + // is not available, skip any debug info related stuff. + if (!MMI->hasDebugInfo() || + !Asm->getObjFileLowering().getCOFFDebugSymbolsSection()) { + Asm = nullptr; + return; + } + + TheCPU = mapArchToCVCPUType(Triple(M->getTargetTriple()).getArch()); + + // Get the current source language. + const MDNode *Node = *M->debug_compile_units_begin(); + const auto *CU = cast<DICompileUnit>(Node); + + CurrentSourceLanguage = MapDWLangToCVLang(CU->getSourceLanguage()); + + collectGlobalVariableInfo(); + + // Check if we should emit type record hashes. + ConstantInt *GH = + mdconst::extract_or_null<ConstantInt>(M->getModuleFlag("CodeViewGHash")); + EmitDebugGlobalHashes = GH && !GH->isZero(); +} + +void CodeViewDebug::endModule() { + if (!Asm || !MMI->hasDebugInfo()) + return; + + // The COFF .debug$S section consists of several subsections, each starting + // with a 4-byte control code (e.g. 0xF1, 0xF2, etc) and then a 4-byte length + // of the payload followed by the payload itself. The subsections are 4-byte + // aligned. + + // Use the generic .debug$S section, and make a subsection for all the inlined + // subprograms. + switchToDebugSectionForSymbol(nullptr); + + MCSymbol *CompilerInfo = beginCVSubsection(DebugSubsectionKind::Symbols); + emitObjName(); + emitCompilerInformation(); + endCVSubsection(CompilerInfo); + + emitInlineeLinesSubsection(); + + // Emit per-function debug information. + for (auto &P : FnDebugInfo) + if (!P.first->isDeclarationForLinker()) + emitDebugInfoForFunction(P.first, *P.second); + + // Get types used by globals without emitting anything. + // This is meant to collect all static const data members so they can be + // emitted as globals. + collectDebugInfoForGlobals(); + + // Emit retained types. + emitDebugInfoForRetainedTypes(); + + // Emit global variable debug information. + setCurrentSubprogram(nullptr); + emitDebugInfoForGlobals(); + + // Switch back to the generic .debug$S section after potentially processing + // comdat symbol sections. + switchToDebugSectionForSymbol(nullptr); + + // Emit UDT records for any types used by global variables. + if (!GlobalUDTs.empty()) { + MCSymbol *SymbolsEnd = beginCVSubsection(DebugSubsectionKind::Symbols); + emitDebugInfoForUDTs(GlobalUDTs); + endCVSubsection(SymbolsEnd); + } + + // This subsection holds a file index to offset in string table table. + OS.AddComment("File index to string table offset subsection"); + OS.emitCVFileChecksumsDirective(); + + // This subsection holds the string table. + OS.AddComment("String table"); + OS.emitCVStringTableDirective(); + + // Emit S_BUILDINFO, which points to LF_BUILDINFO. Put this in its own symbol + // subsection in the generic .debug$S section at the end. There is no + // particular reason for this ordering other than to match MSVC. + emitBuildInfo(); + + // Emit type information and hashes last, so that any types we translate while + // emitting function info are included. + emitTypeInformation(); + + if (EmitDebugGlobalHashes) + emitTypeGlobalHashes(); + + clear(); +} + +static void +emitNullTerminatedSymbolName(MCStreamer &OS, StringRef S, + unsigned MaxFixedRecordLength = 0xF00) { + // The maximum CV record length is 0xFF00. Most of the strings we emit appear + // after a fixed length portion of the record. The fixed length portion should + // always be less than 0xF00 (3840) bytes, so truncate the string so that the + // overall record size is less than the maximum allowed. + SmallString<32> NullTerminatedString( + S.take_front(MaxRecordLength - MaxFixedRecordLength - 1)); + NullTerminatedString.push_back('\0'); + OS.emitBytes(NullTerminatedString); +} + +void CodeViewDebug::emitTypeInformation() { + if (TypeTable.empty()) + return; + + // Start the .debug$T or .debug$P section with 0x4. + OS.switchSection(Asm->getObjFileLowering().getCOFFDebugTypesSection()); + emitCodeViewMagicVersion(); + + TypeTableCollection Table(TypeTable.records()); + TypeVisitorCallbackPipeline Pipeline; + + // To emit type record using Codeview MCStreamer adapter + CVMCAdapter CVMCOS(OS, Table); + TypeRecordMapping typeMapping(CVMCOS); + Pipeline.addCallbackToPipeline(typeMapping); + + std::optional<TypeIndex> B = Table.getFirst(); + while (B) { + // This will fail if the record data is invalid. + CVType Record = Table.getType(*B); + + Error E = codeview::visitTypeRecord(Record, *B, Pipeline); + + if (E) { + logAllUnhandledErrors(std::move(E), errs(), "error: "); + llvm_unreachable("produced malformed type record"); + } + + B = Table.getNext(*B); + } +} + +void CodeViewDebug::emitTypeGlobalHashes() { + if (TypeTable.empty()) + return; + + // Start the .debug$H section with the version and hash algorithm, currently + // hardcoded to version 0, SHA1. + OS.switchSection(Asm->getObjFileLowering().getCOFFGlobalTypeHashesSection()); + + OS.emitValueToAlignment(Align(4)); + OS.AddComment("Magic"); + OS.emitInt32(COFF::DEBUG_HASHES_SECTION_MAGIC); + OS.AddComment("Section Version"); + OS.emitInt16(0); + OS.AddComment("Hash Algorithm"); + OS.emitInt16(uint16_t(GlobalTypeHashAlg::BLAKE3)); + + TypeIndex TI(TypeIndex::FirstNonSimpleIndex); + for (const auto &GHR : TypeTable.hashes()) { + if (OS.isVerboseAsm()) { + // Emit an EOL-comment describing which TypeIndex this hash corresponds + // to, as well as the stringified SHA1 hash. + SmallString<32> Comment; + raw_svector_ostream CommentOS(Comment); + CommentOS << formatv("{0:X+} [{1}]", TI.getIndex(), GHR); + OS.AddComment(Comment); + ++TI; + } + assert(GHR.Hash.size() == 8); + StringRef S(reinterpret_cast<const char *>(GHR.Hash.data()), + GHR.Hash.size()); + OS.emitBinaryData(S); + } +} + +void CodeViewDebug::emitObjName() { + MCSymbol *CompilerEnd = beginSymbolRecord(SymbolKind::S_OBJNAME); + + StringRef PathRef(Asm->TM.Options.ObjectFilenameForDebug); + llvm::SmallString<256> PathStore(PathRef); + + if (PathRef.empty() || PathRef == "-") { + // Don't emit the filename if we're writing to stdout or to /dev/null. + PathRef = {}; + } else { + PathRef = PathStore; + } + + OS.AddComment("Signature"); + OS.emitIntValue(0, 4); + + OS.AddComment("Object name"); + emitNullTerminatedSymbolName(OS, PathRef); + + endSymbolRecord(CompilerEnd); +} + +namespace { +struct Version { + int Part[4]; +}; +} // end anonymous namespace + +// Takes a StringRef like "clang 4.0.0.0 (other nonsense 123)" and parses out +// the version number. +static Version parseVersion(StringRef Name) { + Version V = {{0}}; + int N = 0; + for (const char C : Name) { + if (isdigit(C)) { + V.Part[N] *= 10; + V.Part[N] += C - '0'; + V.Part[N] = + std::min<int>(V.Part[N], std::numeric_limits<uint16_t>::max()); + } else if (C == '.') { + ++N; + if (N >= 4) + return V; + } else if (N > 0) + return V; + } + return V; +} + +void CodeViewDebug::emitCompilerInformation() { + MCSymbol *CompilerEnd = beginSymbolRecord(SymbolKind::S_COMPILE3); + uint32_t Flags = 0; + + // The low byte of the flags indicates the source language. + Flags = CurrentSourceLanguage; + // TODO: Figure out which other flags need to be set. + if (MMI->getModule()->getProfileSummary(/*IsCS*/ false) != nullptr) { + Flags |= static_cast<uint32_t>(CompileSym3Flags::PGO); + } + using ArchType = llvm::Triple::ArchType; + ArchType Arch = Triple(MMI->getModule()->getTargetTriple()).getArch(); + if (Asm->TM.Options.Hotpatch || Arch == ArchType::thumb || + Arch == ArchType::aarch64) { + Flags |= static_cast<uint32_t>(CompileSym3Flags::HotPatch); + } + + OS.AddComment("Flags and language"); + OS.emitInt32(Flags); + + OS.AddComment("CPUType"); + OS.emitInt16(static_cast<uint64_t>(TheCPU)); + + NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu"); + const MDNode *Node = *CUs->operands().begin(); + const auto *CU = cast<DICompileUnit>(Node); + + StringRef CompilerVersion = CU->getProducer(); + Version FrontVer = parseVersion(CompilerVersion); + OS.AddComment("Frontend version"); + for (int N : FrontVer.Part) { + OS.emitInt16(N); + } + + // Some Microsoft tools, like Binscope, expect a backend version number of at + // least 8.something, so we'll coerce the LLVM version into a form that + // guarantees it'll be big enough without really lying about the version. + int Major = 1000 * LLVM_VERSION_MAJOR + + 10 * LLVM_VERSION_MINOR + + LLVM_VERSION_PATCH; + // Clamp it for builds that use unusually large version numbers. + Major = std::min<int>(Major, std::numeric_limits<uint16_t>::max()); + Version BackVer = {{ Major, 0, 0, 0 }}; + OS.AddComment("Backend version"); + for (int N : BackVer.Part) + OS.emitInt16(N); + + OS.AddComment("Null-terminated compiler version string"); + emitNullTerminatedSymbolName(OS, CompilerVersion); + + endSymbolRecord(CompilerEnd); +} + +static TypeIndex getStringIdTypeIdx(GlobalTypeTableBuilder &TypeTable, + StringRef S) { + StringIdRecord SIR(TypeIndex(0x0), S); + return TypeTable.writeLeafType(SIR); +} + +static std::string flattenCommandLine(ArrayRef<std::string> Args, + StringRef MainFilename) { + std::string FlatCmdLine; + raw_string_ostream OS(FlatCmdLine); + bool PrintedOneArg = false; + if (!StringRef(Args[0]).contains("-cc1")) { + llvm::sys::printArg(OS, "-cc1", /*Quote=*/true); + PrintedOneArg = true; + } + for (unsigned i = 0; i < Args.size(); i++) { + StringRef Arg = Args[i]; + if (Arg.empty()) + continue; + if (Arg == "-main-file-name" || Arg == "-o") { + i++; // Skip this argument and next one. + continue; + } + if (Arg.startswith("-object-file-name") || Arg == MainFilename) + continue; + // Skip fmessage-length for reproduciability. + if (Arg.startswith("-fmessage-length")) + continue; + if (PrintedOneArg) + OS << " "; + llvm::sys::printArg(OS, Arg, /*Quote=*/true); + PrintedOneArg = true; + } + OS.flush(); + return FlatCmdLine; +} + +void CodeViewDebug::emitBuildInfo() { + // First, make LF_BUILDINFO. It's a sequence of strings with various bits of + // build info. The known prefix is: + // - Absolute path of current directory + // - Compiler path + // - Main source file path, relative to CWD or absolute + // - Type server PDB file + // - Canonical compiler command line + // If frontend and backend compilation are separated (think llc or LTO), it's + // not clear if the compiler path should refer to the executable for the + // frontend or the backend. Leave it blank for now. + TypeIndex BuildInfoArgs[BuildInfoRecord::MaxArgs] = {}; + NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu"); + const MDNode *Node = *CUs->operands().begin(); // FIXME: Multiple CUs. + const auto *CU = cast<DICompileUnit>(Node); + const DIFile *MainSourceFile = CU->getFile(); + BuildInfoArgs[BuildInfoRecord::CurrentDirectory] = + getStringIdTypeIdx(TypeTable, MainSourceFile->getDirectory()); + BuildInfoArgs[BuildInfoRecord::SourceFile] = + getStringIdTypeIdx(TypeTable, MainSourceFile->getFilename()); + // FIXME: PDB is intentionally blank unless we implement /Zi type servers. + BuildInfoArgs[BuildInfoRecord::TypeServerPDB] = + getStringIdTypeIdx(TypeTable, ""); + if (Asm->TM.Options.MCOptions.Argv0 != nullptr) { + BuildInfoArgs[BuildInfoRecord::BuildTool] = + getStringIdTypeIdx(TypeTable, Asm->TM.Options.MCOptions.Argv0); + BuildInfoArgs[BuildInfoRecord::CommandLine] = getStringIdTypeIdx( + TypeTable, flattenCommandLine(Asm->TM.Options.MCOptions.CommandLineArgs, + MainSourceFile->getFilename())); + } + BuildInfoRecord BIR(BuildInfoArgs); + TypeIndex BuildInfoIndex = TypeTable.writeLeafType(BIR); + + // Make a new .debug$S subsection for the S_BUILDINFO record, which points + // from the module symbols into the type stream. + MCSymbol *BISubsecEnd = beginCVSubsection(DebugSubsectionKind::Symbols); + MCSymbol *BIEnd = beginSymbolRecord(SymbolKind::S_BUILDINFO); + OS.AddComment("LF_BUILDINFO index"); + OS.emitInt32(BuildInfoIndex.getIndex()); + endSymbolRecord(BIEnd); + endCVSubsection(BISubsecEnd); +} + +void CodeViewDebug::emitInlineeLinesSubsection() { + if (InlinedSubprograms.empty()) + return; + + OS.AddComment("Inlinee lines subsection"); + MCSymbol *InlineEnd = beginCVSubsection(DebugSubsectionKind::InlineeLines); + + // We emit the checksum info for files. This is used by debuggers to + // determine if a pdb matches the source before loading it. Visual Studio, + // for instance, will display a warning that the breakpoints are not valid if + // the pdb does not match the source. + OS.AddComment("Inlinee lines signature"); + OS.emitInt32(unsigned(InlineeLinesSignature::Normal)); + + for (const DISubprogram *SP : InlinedSubprograms) { + assert(TypeIndices.count({SP, nullptr})); + TypeIndex InlineeIdx = TypeIndices[{SP, nullptr}]; + + OS.addBlankLine(); + unsigned FileId = maybeRecordFile(SP->getFile()); + OS.AddComment("Inlined function " + SP->getName() + " starts at " + + SP->getFilename() + Twine(':') + Twine(SP->getLine())); + OS.addBlankLine(); + OS.AddComment("Type index of inlined function"); + OS.emitInt32(InlineeIdx.getIndex()); + OS.AddComment("Offset into filechecksum table"); + OS.emitCVFileChecksumOffsetDirective(FileId); + OS.AddComment("Starting line number"); + OS.emitInt32(SP->getLine()); + } + + endCVSubsection(InlineEnd); +} + +void CodeViewDebug::emitInlinedCallSite(const FunctionInfo &FI, + const DILocation *InlinedAt, + const InlineSite &Site) { + assert(TypeIndices.count({Site.Inlinee, nullptr})); + TypeIndex InlineeIdx = TypeIndices[{Site.Inlinee, nullptr}]; + + // SymbolRecord + MCSymbol *InlineEnd = beginSymbolRecord(SymbolKind::S_INLINESITE); + + OS.AddComment("PtrParent"); + OS.emitInt32(0); + OS.AddComment("PtrEnd"); + OS.emitInt32(0); + OS.AddComment("Inlinee type index"); + OS.emitInt32(InlineeIdx.getIndex()); + + unsigned FileId = maybeRecordFile(Site.Inlinee->getFile()); + unsigned StartLineNum = Site.Inlinee->getLine(); + + OS.emitCVInlineLinetableDirective(Site.SiteFuncId, FileId, StartLineNum, + FI.Begin, FI.End); + + endSymbolRecord(InlineEnd); + + emitLocalVariableList(FI, Site.InlinedLocals); + + // Recurse on child inlined call sites before closing the scope. + for (const DILocation *ChildSite : Site.ChildSites) { + auto I = FI.InlineSites.find(ChildSite); + assert(I != FI.InlineSites.end() && + "child site not in function inline site map"); + emitInlinedCallSite(FI, ChildSite, I->second); + } + + // Close the scope. + emitEndSymbolRecord(SymbolKind::S_INLINESITE_END); +} + +void CodeViewDebug::switchToDebugSectionForSymbol(const MCSymbol *GVSym) { + // If we have a symbol, it may be in a section that is COMDAT. If so, find the + // comdat key. A section may be comdat because of -ffunction-sections or + // because it is comdat in the IR. + MCSectionCOFF *GVSec = + GVSym ? dyn_cast<MCSectionCOFF>(&GVSym->getSection()) : nullptr; + const MCSymbol *KeySym = GVSec ? GVSec->getCOMDATSymbol() : nullptr; + + MCSectionCOFF *DebugSec = cast<MCSectionCOFF>( + Asm->getObjFileLowering().getCOFFDebugSymbolsSection()); + DebugSec = OS.getContext().getAssociativeCOFFSection(DebugSec, KeySym); + + OS.switchSection(DebugSec); + + // Emit the magic version number if this is the first time we've switched to + // this section. + if (ComdatDebugSections.insert(DebugSec).second) + emitCodeViewMagicVersion(); +} + +// Emit an S_THUNK32/S_END symbol pair for a thunk routine. +// The only supported thunk ordinal is currently the standard type. +void CodeViewDebug::emitDebugInfoForThunk(const Function *GV, + FunctionInfo &FI, + const MCSymbol *Fn) { + std::string FuncName = + std::string(GlobalValue::dropLLVMManglingEscape(GV->getName())); + const ThunkOrdinal ordinal = ThunkOrdinal::Standard; // Only supported kind. + + OS.AddComment("Symbol subsection for " + Twine(FuncName)); + MCSymbol *SymbolsEnd = beginCVSubsection(DebugSubsectionKind::Symbols); + + // Emit S_THUNK32 + MCSymbol *ThunkRecordEnd = beginSymbolRecord(SymbolKind::S_THUNK32); + OS.AddComment("PtrParent"); + OS.emitInt32(0); + OS.AddComment("PtrEnd"); + OS.emitInt32(0); + OS.AddComment("PtrNext"); + OS.emitInt32(0); + OS.AddComment("Thunk section relative address"); + OS.emitCOFFSecRel32(Fn, /*Offset=*/0); + OS.AddComment("Thunk section index"); + OS.emitCOFFSectionIndex(Fn); + OS.AddComment("Code size"); + OS.emitAbsoluteSymbolDiff(FI.End, Fn, 2); + OS.AddComment("Ordinal"); + OS.emitInt8(unsigned(ordinal)); + OS.AddComment("Function name"); + emitNullTerminatedSymbolName(OS, FuncName); + // Additional fields specific to the thunk ordinal would go here. + endSymbolRecord(ThunkRecordEnd); + + // Local variables/inlined routines are purposely omitted here. The point of + // marking this as a thunk is so Visual Studio will NOT stop in this routine. + + // Emit S_PROC_ID_END + emitEndSymbolRecord(SymbolKind::S_PROC_ID_END); + + endCVSubsection(SymbolsEnd); +} + +void CodeViewDebug::emitDebugInfoForFunction(const Function *GV, + FunctionInfo &FI) { + // For each function there is a separate subsection which holds the PC to + // file:line table. + const MCSymbol *Fn = Asm->getSymbol(GV); + assert(Fn); + + // Switch to the to a comdat section, if appropriate. + switchToDebugSectionForSymbol(Fn); + + std::string FuncName; + auto *SP = GV->getSubprogram(); + assert(SP); + setCurrentSubprogram(SP); + + if (SP->isThunk()) { + emitDebugInfoForThunk(GV, FI, Fn); + return; + } + + // If we have a display name, build the fully qualified name by walking the + // chain of scopes. + if (!SP->getName().empty()) + FuncName = getFullyQualifiedName(SP->getScope(), SP->getName()); + + // If our DISubprogram name is empty, use the mangled name. + if (FuncName.empty()) + FuncName = std::string(GlobalValue::dropLLVMManglingEscape(GV->getName())); + + // Emit FPO data, but only on 32-bit x86. No other platforms use it. + if (Triple(MMI->getModule()->getTargetTriple()).getArch() == Triple::x86) + OS.emitCVFPOData(Fn); + + // Emit a symbol subsection, required by VS2012+ to find function boundaries. + OS.AddComment("Symbol subsection for " + Twine(FuncName)); + MCSymbol *SymbolsEnd = beginCVSubsection(DebugSubsectionKind::Symbols); + { + SymbolKind ProcKind = GV->hasLocalLinkage() ? SymbolKind::S_LPROC32_ID + : SymbolKind::S_GPROC32_ID; + MCSymbol *ProcRecordEnd = beginSymbolRecord(ProcKind); + + // These fields are filled in by tools like CVPACK which run after the fact. + OS.AddComment("PtrParent"); + OS.emitInt32(0); + OS.AddComment("PtrEnd"); + OS.emitInt32(0); + OS.AddComment("PtrNext"); + OS.emitInt32(0); + // This is the important bit that tells the debugger where the function + // code is located and what's its size: + OS.AddComment("Code size"); + OS.emitAbsoluteSymbolDiff(FI.End, Fn, 4); + OS.AddComment("Offset after prologue"); + OS.emitInt32(0); + OS.AddComment("Offset before epilogue"); + OS.emitInt32(0); + OS.AddComment("Function type index"); + OS.emitInt32(getFuncIdForSubprogram(GV->getSubprogram()).getIndex()); + OS.AddComment("Function section relative address"); + OS.emitCOFFSecRel32(Fn, /*Offset=*/0); + OS.AddComment("Function section index"); + OS.emitCOFFSectionIndex(Fn); + OS.AddComment("Flags"); + ProcSymFlags ProcFlags = ProcSymFlags::HasOptimizedDebugInfo; + if (FI.HasFramePointer) + ProcFlags |= ProcSymFlags::HasFP; + if (GV->hasFnAttribute(Attribute::NoReturn)) + ProcFlags |= ProcSymFlags::IsNoReturn; + if (GV->hasFnAttribute(Attribute::NoInline)) + ProcFlags |= ProcSymFlags::IsNoInline; + OS.emitInt8(static_cast<uint8_t>(ProcFlags)); + // Emit the function display name as a null-terminated string. + OS.AddComment("Function name"); + // Truncate the name so we won't overflow the record length field. + emitNullTerminatedSymbolName(OS, FuncName); + endSymbolRecord(ProcRecordEnd); + + MCSymbol *FrameProcEnd = beginSymbolRecord(SymbolKind::S_FRAMEPROC); + // Subtract out the CSR size since MSVC excludes that and we include it. + OS.AddComment("FrameSize"); + OS.emitInt32(FI.FrameSize - FI.CSRSize); + OS.AddComment("Padding"); + OS.emitInt32(0); + OS.AddComment("Offset of padding"); + OS.emitInt32(0); + OS.AddComment("Bytes of callee saved registers"); + OS.emitInt32(FI.CSRSize); + OS.AddComment("Exception handler offset"); + OS.emitInt32(0); + OS.AddComment("Exception handler section"); + OS.emitInt16(0); + OS.AddComment("Flags (defines frame register)"); + OS.emitInt32(uint32_t(FI.FrameProcOpts)); + endSymbolRecord(FrameProcEnd); + + emitLocalVariableList(FI, FI.Locals); + emitGlobalVariableList(FI.Globals); + emitLexicalBlockList(FI.ChildBlocks, FI); + + // Emit inlined call site information. Only emit functions inlined directly + // into the parent function. We'll emit the other sites recursively as part + // of their parent inline site. + for (const DILocation *InlinedAt : FI.ChildSites) { + auto I = FI.InlineSites.find(InlinedAt); + assert(I != FI.InlineSites.end() && + "child site not in function inline site map"); + emitInlinedCallSite(FI, InlinedAt, I->second); + } + + for (auto Annot : FI.Annotations) { + MCSymbol *Label = Annot.first; + MDTuple *Strs = cast<MDTuple>(Annot.second); + MCSymbol *AnnotEnd = beginSymbolRecord(SymbolKind::S_ANNOTATION); + OS.emitCOFFSecRel32(Label, /*Offset=*/0); + // FIXME: Make sure we don't overflow the max record size. + OS.emitCOFFSectionIndex(Label); + OS.emitInt16(Strs->getNumOperands()); + for (Metadata *MD : Strs->operands()) { + // MDStrings are null terminated, so we can do EmitBytes and get the + // nice .asciz directive. + StringRef Str = cast<MDString>(MD)->getString(); + assert(Str.data()[Str.size()] == '\0' && "non-nullterminated MDString"); + OS.emitBytes(StringRef(Str.data(), Str.size() + 1)); + } + endSymbolRecord(AnnotEnd); + } + + for (auto HeapAllocSite : FI.HeapAllocSites) { + const MCSymbol *BeginLabel = std::get<0>(HeapAllocSite); + const MCSymbol *EndLabel = std::get<1>(HeapAllocSite); + const DIType *DITy = std::get<2>(HeapAllocSite); + MCSymbol *HeapAllocEnd = beginSymbolRecord(SymbolKind::S_HEAPALLOCSITE); + OS.AddComment("Call site offset"); + OS.emitCOFFSecRel32(BeginLabel, /*Offset=*/0); + OS.AddComment("Call site section index"); + OS.emitCOFFSectionIndex(BeginLabel); + OS.AddComment("Call instruction length"); + OS.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 2); + OS.AddComment("Type index"); + OS.emitInt32(getCompleteTypeIndex(DITy).getIndex()); + endSymbolRecord(HeapAllocEnd); + } + + if (SP != nullptr) + emitDebugInfoForUDTs(LocalUDTs); + + // We're done with this function. + emitEndSymbolRecord(SymbolKind::S_PROC_ID_END); + } + endCVSubsection(SymbolsEnd); + + // We have an assembler directive that takes care of the whole line table. + OS.emitCVLinetableDirective(FI.FuncId, Fn, FI.End); +} + +CodeViewDebug::LocalVarDef +CodeViewDebug::createDefRangeMem(uint16_t CVRegister, int Offset) { + LocalVarDef DR; + DR.InMemory = -1; + DR.DataOffset = Offset; + assert(DR.DataOffset == Offset && "truncation"); + DR.IsSubfield = 0; + DR.StructOffset = 0; + DR.CVRegister = CVRegister; + return DR; +} + +void CodeViewDebug::collectVariableInfoFromMFTable( + DenseSet<InlinedEntity> &Processed) { + const MachineFunction &MF = *Asm->MF; + const TargetSubtargetInfo &TSI = MF.getSubtarget(); + const TargetFrameLowering *TFI = TSI.getFrameLowering(); + const TargetRegisterInfo *TRI = TSI.getRegisterInfo(); + + for (const MachineFunction::VariableDbgInfo &VI : + MF.getInStackSlotVariableDbgInfo()) { + if (!VI.Var) + continue; + assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) && + "Expected inlined-at fields to agree"); + + Processed.insert(InlinedEntity(VI.Var, VI.Loc->getInlinedAt())); + LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc); + + // If variable scope is not found then skip this variable. + if (!Scope) + continue; + + // If the variable has an attached offset expression, extract it. + // FIXME: Try to handle DW_OP_deref as well. + int64_t ExprOffset = 0; + bool Deref = false; + if (VI.Expr) { + // If there is one DW_OP_deref element, use offset of 0 and keep going. + if (VI.Expr->getNumElements() == 1 && + VI.Expr->getElement(0) == llvm::dwarf::DW_OP_deref) + Deref = true; + else if (!VI.Expr->extractIfOffset(ExprOffset)) + continue; + } + + // Get the frame register used and the offset. + Register FrameReg; + StackOffset FrameOffset = + TFI->getFrameIndexReference(*Asm->MF, VI.getStackSlot(), FrameReg); + uint16_t CVReg = TRI->getCodeViewRegNum(FrameReg); + + assert(!FrameOffset.getScalable() && + "Frame offsets with a scalable component are not supported"); + + // Calculate the label ranges. + LocalVarDef DefRange = + createDefRangeMem(CVReg, FrameOffset.getFixed() + ExprOffset); + + LocalVariable Var; + Var.DIVar = VI.Var; + + for (const InsnRange &Range : Scope->getRanges()) { + const MCSymbol *Begin = getLabelBeforeInsn(Range.first); + const MCSymbol *End = getLabelAfterInsn(Range.second); + End = End ? End : Asm->getFunctionEnd(); + Var.DefRanges[DefRange].emplace_back(Begin, End); + } + + if (Deref) + Var.UseReferenceType = true; + + recordLocalVariable(std::move(Var), Scope); + } +} + +static bool canUseReferenceType(const DbgVariableLocation &Loc) { + return !Loc.LoadChain.empty() && Loc.LoadChain.back() == 0; +} + +static bool needsReferenceType(const DbgVariableLocation &Loc) { + return Loc.LoadChain.size() == 2 && Loc.LoadChain.back() == 0; +} + +void CodeViewDebug::calculateRanges( + LocalVariable &Var, const DbgValueHistoryMap::Entries &Entries) { + const TargetRegisterInfo *TRI = Asm->MF->getSubtarget().getRegisterInfo(); + + // Calculate the definition ranges. + for (auto I = Entries.begin(), E = Entries.end(); I != E; ++I) { + const auto &Entry = *I; + if (!Entry.isDbgValue()) + continue; + const MachineInstr *DVInst = Entry.getInstr(); + assert(DVInst->isDebugValue() && "Invalid History entry"); + // FIXME: Find a way to represent constant variables, since they are + // relatively common. + std::optional<DbgVariableLocation> Location = + DbgVariableLocation::extractFromMachineInstruction(*DVInst); + if (!Location) + { + // When we don't have a location this is usually because LLVM has + // transformed it into a constant and we only have an llvm.dbg.value. We + // can't represent these well in CodeView since S_LOCAL only works on + // registers and memory locations. Instead, we will pretend this to be a + // constant value to at least have it show up in the debugger. + auto Op = DVInst->getDebugOperand(0); + if (Op.isImm()) + Var.ConstantValue = APSInt(APInt(64, Op.getImm()), false); + continue; + } + + // CodeView can only express variables in register and variables in memory + // at a constant offset from a register. However, for variables passed + // indirectly by pointer, it is common for that pointer to be spilled to a + // stack location. For the special case of one offseted load followed by a + // zero offset load (a pointer spilled to the stack), we change the type of + // the local variable from a value type to a reference type. This tricks the + // debugger into doing the load for us. + if (Var.UseReferenceType) { + // We're using a reference type. Drop the last zero offset load. + if (canUseReferenceType(*Location)) + Location->LoadChain.pop_back(); + else + continue; + } else if (needsReferenceType(*Location)) { + // This location can't be expressed without switching to a reference type. + // Start over using that. + Var.UseReferenceType = true; + Var.DefRanges.clear(); + calculateRanges(Var, Entries); + return; + } + + // We can only handle a register or an offseted load of a register. + if (Location->Register == 0 || Location->LoadChain.size() > 1) + continue; + + LocalVarDef DR; + DR.CVRegister = TRI->getCodeViewRegNum(Location->Register); + DR.InMemory = !Location->LoadChain.empty(); + DR.DataOffset = + !Location->LoadChain.empty() ? Location->LoadChain.back() : 0; + if (Location->FragmentInfo) { + DR.IsSubfield = true; + DR.StructOffset = Location->FragmentInfo->OffsetInBits / 8; + } else { + DR.IsSubfield = false; + DR.StructOffset = 0; + } + + // Compute the label range. + const MCSymbol *Begin = getLabelBeforeInsn(Entry.getInstr()); + const MCSymbol *End; + if (Entry.getEndIndex() != DbgValueHistoryMap::NoEntry) { + auto &EndingEntry = Entries[Entry.getEndIndex()]; + End = EndingEntry.isDbgValue() + ? getLabelBeforeInsn(EndingEntry.getInstr()) + : getLabelAfterInsn(EndingEntry.getInstr()); + } else + End = Asm->getFunctionEnd(); + + // If the last range end is our begin, just extend the last range. + // Otherwise make a new range. + SmallVectorImpl<std::pair<const MCSymbol *, const MCSymbol *>> &R = + Var.DefRanges[DR]; + if (!R.empty() && R.back().second == Begin) + R.back().second = End; + else + R.emplace_back(Begin, End); + + // FIXME: Do more range combining. + } +} + +void CodeViewDebug::collectVariableInfo(const DISubprogram *SP) { + DenseSet<InlinedEntity> Processed; + // Grab the variable info that was squirreled away in the MMI side-table. + collectVariableInfoFromMFTable(Processed); + + for (const auto &I : DbgValues) { + InlinedEntity IV = I.first; + if (Processed.count(IV)) + continue; + const DILocalVariable *DIVar = cast<DILocalVariable>(IV.first); + const DILocation *InlinedAt = IV.second; + + // Instruction ranges, specifying where IV is accessible. + const auto &Entries = I.second; + + LexicalScope *Scope = nullptr; + if (InlinedAt) + Scope = LScopes.findInlinedScope(DIVar->getScope(), InlinedAt); + else + Scope = LScopes.findLexicalScope(DIVar->getScope()); + // If variable scope is not found then skip this variable. + if (!Scope) + continue; + + LocalVariable Var; + Var.DIVar = DIVar; + + calculateRanges(Var, Entries); + recordLocalVariable(std::move(Var), Scope); + } +} + +void CodeViewDebug::beginFunctionImpl(const MachineFunction *MF) { + const TargetSubtargetInfo &TSI = MF->getSubtarget(); + const TargetRegisterInfo *TRI = TSI.getRegisterInfo(); + const MachineFrameInfo &MFI = MF->getFrameInfo(); + const Function &GV = MF->getFunction(); + auto Insertion = FnDebugInfo.insert({&GV, std::make_unique<FunctionInfo>()}); + assert(Insertion.second && "function already has info"); + CurFn = Insertion.first->second.get(); + CurFn->FuncId = NextFuncId++; + CurFn->Begin = Asm->getFunctionBegin(); + + // The S_FRAMEPROC record reports the stack size, and how many bytes of + // callee-saved registers were used. For targets that don't use a PUSH + // instruction (AArch64), this will be zero. + CurFn->CSRSize = MFI.getCVBytesOfCalleeSavedRegisters(); + CurFn->FrameSize = MFI.getStackSize(); + CurFn->OffsetAdjustment = MFI.getOffsetAdjustment(); + CurFn->HasStackRealignment = TRI->hasStackRealignment(*MF); + + // For this function S_FRAMEPROC record, figure out which codeview register + // will be the frame pointer. + CurFn->EncodedParamFramePtrReg = EncodedFramePtrReg::None; // None. + CurFn->EncodedLocalFramePtrReg = EncodedFramePtrReg::None; // None. + if (CurFn->FrameSize > 0) { + if (!TSI.getFrameLowering()->hasFP(*MF)) { + CurFn->EncodedLocalFramePtrReg = EncodedFramePtrReg::StackPtr; + CurFn->EncodedParamFramePtrReg = EncodedFramePtrReg::StackPtr; + } else { + CurFn->HasFramePointer = true; + // If there is an FP, parameters are always relative to it. + CurFn->EncodedParamFramePtrReg = EncodedFramePtrReg::FramePtr; + if (CurFn->HasStackRealignment) { + // If the stack needs realignment, locals are relative to SP or VFRAME. + CurFn->EncodedLocalFramePtrReg = EncodedFramePtrReg::StackPtr; + } else { + // Otherwise, locals are relative to EBP, and we probably have VLAs or + // other stack adjustments. + CurFn->EncodedLocalFramePtrReg = EncodedFramePtrReg::FramePtr; + } + } + } + + // Compute other frame procedure options. + FrameProcedureOptions FPO = FrameProcedureOptions::None; + if (MFI.hasVarSizedObjects()) + FPO |= FrameProcedureOptions::HasAlloca; + if (MF->exposesReturnsTwice()) + FPO |= FrameProcedureOptions::HasSetJmp; + // FIXME: Set HasLongJmp if we ever track that info. + if (MF->hasInlineAsm()) + FPO |= FrameProcedureOptions::HasInlineAssembly; + if (GV.hasPersonalityFn()) { + if (isAsynchronousEHPersonality( + classifyEHPersonality(GV.getPersonalityFn()))) + FPO |= FrameProcedureOptions::HasStructuredExceptionHandling; + else + FPO |= FrameProcedureOptions::HasExceptionHandling; + } + if (GV.hasFnAttribute(Attribute::InlineHint)) + FPO |= FrameProcedureOptions::MarkedInline; + if (GV.hasFnAttribute(Attribute::Naked)) + FPO |= FrameProcedureOptions::Naked; + if (MFI.hasStackProtectorIndex()) { + FPO |= FrameProcedureOptions::SecurityChecks; + if (GV.hasFnAttribute(Attribute::StackProtectStrong) || + GV.hasFnAttribute(Attribute::StackProtectReq)) { + FPO |= FrameProcedureOptions::StrictSecurityChecks; + } + } else if (!GV.hasStackProtectorFnAttr()) { + // __declspec(safebuffers) disables stack guards. + FPO |= FrameProcedureOptions::SafeBuffers; + } + FPO |= FrameProcedureOptions(uint32_t(CurFn->EncodedLocalFramePtrReg) << 14U); + FPO |= FrameProcedureOptions(uint32_t(CurFn->EncodedParamFramePtrReg) << 16U); + if (Asm->TM.getOptLevel() != CodeGenOpt::None && + !GV.hasOptSize() && !GV.hasOptNone()) + FPO |= FrameProcedureOptions::OptimizedForSpeed; + if (GV.hasProfileData()) { + FPO |= FrameProcedureOptions::ValidProfileCounts; + FPO |= FrameProcedureOptions::ProfileGuidedOptimization; + } + // FIXME: Set GuardCfg when it is implemented. + CurFn->FrameProcOpts = FPO; + + OS.emitCVFuncIdDirective(CurFn->FuncId); + + // Find the end of the function prolog. First known non-DBG_VALUE and + // non-frame setup location marks the beginning of the function body. + // FIXME: is there a simpler a way to do this? Can we just search + // for the first instruction of the function, not the last of the prolog? + DebugLoc PrologEndLoc; + bool EmptyPrologue = true; + for (const auto &MBB : *MF) { + for (const auto &MI : MBB) { + if (!MI.isMetaInstruction() && !MI.getFlag(MachineInstr::FrameSetup) && + MI.getDebugLoc()) { + PrologEndLoc = MI.getDebugLoc(); + break; + } else if (!MI.isMetaInstruction()) { + EmptyPrologue = false; + } + } + } + + // Record beginning of function if we have a non-empty prologue. + if (PrologEndLoc && !EmptyPrologue) { + DebugLoc FnStartDL = PrologEndLoc.getFnDebugLoc(); + maybeRecordLocation(FnStartDL, MF); + } + + // Find heap alloc sites and emit labels around them. + for (const auto &MBB : *MF) { + for (const auto &MI : MBB) { + if (MI.getHeapAllocMarker()) { + requestLabelBeforeInsn(&MI); + requestLabelAfterInsn(&MI); + } + } + } +} + +static bool shouldEmitUdt(const DIType *T) { + if (!T) + return false; + + // MSVC does not emit UDTs for typedefs that are scoped to classes. + if (T->getTag() == dwarf::DW_TAG_typedef) { + if (DIScope *Scope = T->getScope()) { + switch (Scope->getTag()) { + case dwarf::DW_TAG_structure_type: + case dwarf::DW_TAG_class_type: + case dwarf::DW_TAG_union_type: + return false; + default: + // do nothing. + ; + } + } + } + + while (true) { + if (!T || T->isForwardDecl()) + return false; + + const DIDerivedType *DT = dyn_cast<DIDerivedType>(T); + if (!DT) + return true; + T = DT->getBaseType(); + } + return true; +} + +void CodeViewDebug::addToUDTs(const DIType *Ty) { + // Don't record empty UDTs. + if (Ty->getName().empty()) + return; + if (!shouldEmitUdt(Ty)) + return; + + SmallVector<StringRef, 5> ParentScopeNames; + const DISubprogram *ClosestSubprogram = + collectParentScopeNames(Ty->getScope(), ParentScopeNames); + + std::string FullyQualifiedName = + formatNestedName(ParentScopeNames, getPrettyScopeName(Ty)); + + if (ClosestSubprogram == nullptr) { + GlobalUDTs.emplace_back(std::move(FullyQualifiedName), Ty); + } else if (ClosestSubprogram == CurrentSubprogram) { + LocalUDTs.emplace_back(std::move(FullyQualifiedName), Ty); + } + + // TODO: What if the ClosestSubprogram is neither null or the current + // subprogram? Currently, the UDT just gets dropped on the floor. + // + // The current behavior is not desirable. To get maximal fidelity, we would + // need to perform all type translation before beginning emission of .debug$S + // and then make LocalUDTs a member of FunctionInfo +} + +TypeIndex CodeViewDebug::lowerType(const DIType *Ty, const DIType *ClassTy) { + // Generic dispatch for lowering an unknown type. + switch (Ty->getTag()) { + case dwarf::DW_TAG_array_type: + return lowerTypeArray(cast<DICompositeType>(Ty)); + case dwarf::DW_TAG_typedef: + return lowerTypeAlias(cast<DIDerivedType>(Ty)); + case dwarf::DW_TAG_base_type: + return lowerTypeBasic(cast<DIBasicType>(Ty)); + case dwarf::DW_TAG_pointer_type: + if (cast<DIDerivedType>(Ty)->getName() == "__vtbl_ptr_type") + return lowerTypeVFTableShape(cast<DIDerivedType>(Ty)); + [[fallthrough]]; + case dwarf::DW_TAG_reference_type: + case dwarf::DW_TAG_rvalue_reference_type: + return lowerTypePointer(cast<DIDerivedType>(Ty)); + case dwarf::DW_TAG_ptr_to_member_type: + return lowerTypeMemberPointer(cast<DIDerivedType>(Ty)); + case dwarf::DW_TAG_restrict_type: + case dwarf::DW_TAG_const_type: + case dwarf::DW_TAG_volatile_type: + // TODO: add support for DW_TAG_atomic_type here + return lowerTypeModifier(cast<DIDerivedType>(Ty)); + case dwarf::DW_TAG_subroutine_type: + if (ClassTy) { + // The member function type of a member function pointer has no + // ThisAdjustment. + return lowerTypeMemberFunction(cast<DISubroutineType>(Ty), ClassTy, + /*ThisAdjustment=*/0, + /*IsStaticMethod=*/false); + } + return lowerTypeFunction(cast<DISubroutineType>(Ty)); + case dwarf::DW_TAG_enumeration_type: + return lowerTypeEnum(cast<DICompositeType>(Ty)); + case dwarf::DW_TAG_class_type: + case dwarf::DW_TAG_structure_type: + return lowerTypeClass(cast<DICompositeType>(Ty)); + case dwarf::DW_TAG_union_type: + return lowerTypeUnion(cast<DICompositeType>(Ty)); + case dwarf::DW_TAG_string_type: + return lowerTypeString(cast<DIStringType>(Ty)); + case dwarf::DW_TAG_unspecified_type: + if (Ty->getName() == "decltype(nullptr)") + return TypeIndex::NullptrT(); + return TypeIndex::None(); + default: + // Use the null type index. + return TypeIndex(); + } +} + +TypeIndex CodeViewDebug::lowerTypeAlias(const DIDerivedType *Ty) { + TypeIndex UnderlyingTypeIndex = getTypeIndex(Ty->getBaseType()); + StringRef TypeName = Ty->getName(); + + addToUDTs(Ty); + + if (UnderlyingTypeIndex == TypeIndex(SimpleTypeKind::Int32Long) && + TypeName == "HRESULT") + return TypeIndex(SimpleTypeKind::HResult); + if (UnderlyingTypeIndex == TypeIndex(SimpleTypeKind::UInt16Short) && + TypeName == "wchar_t") + return TypeIndex(SimpleTypeKind::WideCharacter); + + return UnderlyingTypeIndex; +} + +TypeIndex CodeViewDebug::lowerTypeArray(const DICompositeType *Ty) { + const DIType *ElementType = Ty->getBaseType(); + TypeIndex ElementTypeIndex = getTypeIndex(ElementType); + // IndexType is size_t, which depends on the bitness of the target. + TypeIndex IndexType = getPointerSizeInBytes() == 8 + ? TypeIndex(SimpleTypeKind::UInt64Quad) + : TypeIndex(SimpleTypeKind::UInt32Long); + + uint64_t ElementSize = getBaseTypeSize(ElementType) / 8; + + // Add subranges to array type. + DINodeArray Elements = Ty->getElements(); + for (int i = Elements.size() - 1; i >= 0; --i) { + const DINode *Element = Elements[i]; + assert(Element->getTag() == dwarf::DW_TAG_subrange_type); + + const DISubrange *Subrange = cast<DISubrange>(Element); + int64_t Count = -1; + + // If Subrange has a Count field, use it. + // Otherwise, if it has an upperboud, use (upperbound - lowerbound + 1), + // where lowerbound is from the LowerBound field of the Subrange, + // or the language default lowerbound if that field is unspecified. + if (auto *CI = dyn_cast_if_present<ConstantInt *>(Subrange->getCount())) + Count = CI->getSExtValue(); + else if (auto *UI = dyn_cast_if_present<ConstantInt *>( + Subrange->getUpperBound())) { + // Fortran uses 1 as the default lowerbound; other languages use 0. + int64_t Lowerbound = (moduleIsInFortran()) ? 1 : 0; + auto *LI = dyn_cast_if_present<ConstantInt *>(Subrange->getLowerBound()); + Lowerbound = (LI) ? LI->getSExtValue() : Lowerbound; + Count = UI->getSExtValue() - Lowerbound + 1; + } + + // Forward declarations of arrays without a size and VLAs use a count of -1. + // Emit a count of zero in these cases to match what MSVC does for arrays + // without a size. MSVC doesn't support VLAs, so it's not clear what we + // should do for them even if we could distinguish them. + if (Count == -1) + Count = 0; + + // Update the element size and element type index for subsequent subranges. + ElementSize *= Count; + + // If this is the outermost array, use the size from the array. It will be + // more accurate if we had a VLA or an incomplete element type size. + uint64_t ArraySize = + (i == 0 && ElementSize == 0) ? Ty->getSizeInBits() / 8 : ElementSize; + + StringRef Name = (i == 0) ? Ty->getName() : ""; + ArrayRecord AR(ElementTypeIndex, IndexType, ArraySize, Name); + ElementTypeIndex = TypeTable.writeLeafType(AR); + } + + return ElementTypeIndex; +} + +// This function lowers a Fortran character type (DIStringType). +// Note that it handles only the character*n variant (using SizeInBits +// field in DIString to describe the type size) at the moment. +// Other variants (leveraging the StringLength and StringLengthExp +// fields in DIStringType) remain TBD. +TypeIndex CodeViewDebug::lowerTypeString(const DIStringType *Ty) { + TypeIndex CharType = TypeIndex(SimpleTypeKind::NarrowCharacter); + uint64_t ArraySize = Ty->getSizeInBits() >> 3; + StringRef Name = Ty->getName(); + // IndexType is size_t, which depends on the bitness of the target. + TypeIndex IndexType = getPointerSizeInBytes() == 8 + ? TypeIndex(SimpleTypeKind::UInt64Quad) + : TypeIndex(SimpleTypeKind::UInt32Long); + + // Create a type of character array of ArraySize. + ArrayRecord AR(CharType, IndexType, ArraySize, Name); + + return TypeTable.writeLeafType(AR); +} + +TypeIndex CodeViewDebug::lowerTypeBasic(const DIBasicType *Ty) { + TypeIndex Index; + dwarf::TypeKind Kind; + uint32_t ByteSize; + + Kind = static_cast<dwarf::TypeKind>(Ty->getEncoding()); + ByteSize = Ty->getSizeInBits() / 8; + + SimpleTypeKind STK = SimpleTypeKind::None; + switch (Kind) { + case dwarf::DW_ATE_address: + // FIXME: Translate + break; + case dwarf::DW_ATE_boolean: + switch (ByteSize) { + case 1: STK = SimpleTypeKind::Boolean8; break; + case 2: STK = SimpleTypeKind::Boolean16; break; + case 4: STK = SimpleTypeKind::Boolean32; break; + case 8: STK = SimpleTypeKind::Boolean64; break; + case 16: STK = SimpleTypeKind::Boolean128; break; + } + break; + case dwarf::DW_ATE_complex_float: + // The CodeView size for a complex represents the size of + // an individual component. + switch (ByteSize) { + case 4: STK = SimpleTypeKind::Complex16; break; + case 8: STK = SimpleTypeKind::Complex32; break; + case 16: STK = SimpleTypeKind::Complex64; break; + case 20: STK = SimpleTypeKind::Complex80; break; + case 32: STK = SimpleTypeKind::Complex128; break; + } + break; + case dwarf::DW_ATE_float: + switch (ByteSize) { + case 2: STK = SimpleTypeKind::Float16; break; + case 4: STK = SimpleTypeKind::Float32; break; + case 6: STK = SimpleTypeKind::Float48; break; + case 8: STK = SimpleTypeKind::Float64; break; + case 10: STK = SimpleTypeKind::Float80; break; + case 16: STK = SimpleTypeKind::Float128; break; + } + break; + case dwarf::DW_ATE_signed: + switch (ByteSize) { + case 1: STK = SimpleTypeKind::SignedCharacter; break; + case 2: STK = SimpleTypeKind::Int16Short; break; + case 4: STK = SimpleTypeKind::Int32; break; + case 8: STK = SimpleTypeKind::Int64Quad; break; + case 16: STK = SimpleTypeKind::Int128Oct; break; + } + break; + case dwarf::DW_ATE_unsigned: + switch (ByteSize) { + case 1: STK = SimpleTypeKind::UnsignedCharacter; break; + case 2: STK = SimpleTypeKind::UInt16Short; break; + case 4: STK = SimpleTypeKind::UInt32; break; + case 8: STK = SimpleTypeKind::UInt64Quad; break; + case 16: STK = SimpleTypeKind::UInt128Oct; break; + } + break; + case dwarf::DW_ATE_UTF: + switch (ByteSize) { + case 1: STK = SimpleTypeKind::Character8; break; + case 2: STK = SimpleTypeKind::Character16; break; + case 4: STK = SimpleTypeKind::Character32; break; + } + break; + case dwarf::DW_ATE_signed_char: + if (ByteSize == 1) + STK = SimpleTypeKind::SignedCharacter; + break; + case dwarf::DW_ATE_unsigned_char: + if (ByteSize == 1) + STK = SimpleTypeKind::UnsignedCharacter; + break; + default: + break; + } + + // Apply some fixups based on the source-level type name. + // Include some amount of canonicalization from an old naming scheme Clang + // used to use for integer types (in an outdated effort to be compatible with + // GCC's debug info/GDB's behavior, which has since been addressed). + if (STK == SimpleTypeKind::Int32 && + (Ty->getName() == "long int" || Ty->getName() == "long")) + STK = SimpleTypeKind::Int32Long; + if (STK == SimpleTypeKind::UInt32 && (Ty->getName() == "long unsigned int" || + Ty->getName() == "unsigned long")) + STK = SimpleTypeKind::UInt32Long; + if (STK == SimpleTypeKind::UInt16Short && + (Ty->getName() == "wchar_t" || Ty->getName() == "__wchar_t")) + STK = SimpleTypeKind::WideCharacter; + if ((STK == SimpleTypeKind::SignedCharacter || + STK == SimpleTypeKind::UnsignedCharacter) && + Ty->getName() == "char") + STK = SimpleTypeKind::NarrowCharacter; + + return TypeIndex(STK); +} + +TypeIndex CodeViewDebug::lowerTypePointer(const DIDerivedType *Ty, + PointerOptions PO) { + TypeIndex PointeeTI = getTypeIndex(Ty->getBaseType()); + + // Pointers to simple types without any options can use SimpleTypeMode, rather + // than having a dedicated pointer type record. + if (PointeeTI.isSimple() && PO == PointerOptions::None && + PointeeTI.getSimpleMode() == SimpleTypeMode::Direct && + Ty->getTag() == dwarf::DW_TAG_pointer_type) { + SimpleTypeMode Mode = Ty->getSizeInBits() == 64 + ? SimpleTypeMode::NearPointer64 + : SimpleTypeMode::NearPointer32; + return TypeIndex(PointeeTI.getSimpleKind(), Mode); + } + + PointerKind PK = + Ty->getSizeInBits() == 64 ? PointerKind::Near64 : PointerKind::Near32; + PointerMode PM = PointerMode::Pointer; + switch (Ty->getTag()) { + default: llvm_unreachable("not a pointer tag type"); + case dwarf::DW_TAG_pointer_type: + PM = PointerMode::Pointer; + break; + case dwarf::DW_TAG_reference_type: + PM = PointerMode::LValueReference; + break; + case dwarf::DW_TAG_rvalue_reference_type: + PM = PointerMode::RValueReference; + break; + } + + if (Ty->isObjectPointer()) + PO |= PointerOptions::Const; + + PointerRecord PR(PointeeTI, PK, PM, PO, Ty->getSizeInBits() / 8); + return TypeTable.writeLeafType(PR); +} + +static PointerToMemberRepresentation +translatePtrToMemberRep(unsigned SizeInBytes, bool IsPMF, unsigned Flags) { + // SizeInBytes being zero generally implies that the member pointer type was + // incomplete, which can happen if it is part of a function prototype. In this + // case, use the unknown model instead of the general model. + if (IsPMF) { + switch (Flags & DINode::FlagPtrToMemberRep) { + case 0: + return SizeInBytes == 0 ? PointerToMemberRepresentation::Unknown + : PointerToMemberRepresentation::GeneralFunction; + case DINode::FlagSingleInheritance: + return PointerToMemberRepresentation::SingleInheritanceFunction; + case DINode::FlagMultipleInheritance: + return PointerToMemberRepresentation::MultipleInheritanceFunction; + case DINode::FlagVirtualInheritance: + return PointerToMemberRepresentation::VirtualInheritanceFunction; + } + } else { + switch (Flags & DINode::FlagPtrToMemberRep) { + case 0: + return SizeInBytes == 0 ? PointerToMemberRepresentation::Unknown + : PointerToMemberRepresentation::GeneralData; + case DINode::FlagSingleInheritance: + return PointerToMemberRepresentation::SingleInheritanceData; + case DINode::FlagMultipleInheritance: + return PointerToMemberRepresentation::MultipleInheritanceData; + case DINode::FlagVirtualInheritance: + return PointerToMemberRepresentation::VirtualInheritanceData; + } + } + llvm_unreachable("invalid ptr to member representation"); +} + +TypeIndex CodeViewDebug::lowerTypeMemberPointer(const DIDerivedType *Ty, + PointerOptions PO) { + assert(Ty->getTag() == dwarf::DW_TAG_ptr_to_member_type); + bool IsPMF = isa<DISubroutineType>(Ty->getBaseType()); + TypeIndex ClassTI = getTypeIndex(Ty->getClassType()); + TypeIndex PointeeTI = + getTypeIndex(Ty->getBaseType(), IsPMF ? Ty->getClassType() : nullptr); + PointerKind PK = getPointerSizeInBytes() == 8 ? PointerKind::Near64 + : PointerKind::Near32; + PointerMode PM = IsPMF ? PointerMode::PointerToMemberFunction + : PointerMode::PointerToDataMember; + + assert(Ty->getSizeInBits() / 8 <= 0xff && "pointer size too big"); + uint8_t SizeInBytes = Ty->getSizeInBits() / 8; + MemberPointerInfo MPI( + ClassTI, translatePtrToMemberRep(SizeInBytes, IsPMF, Ty->getFlags())); + PointerRecord PR(PointeeTI, PK, PM, PO, SizeInBytes, MPI); + return TypeTable.writeLeafType(PR); +} + +/// Given a DWARF calling convention, get the CodeView equivalent. If we don't +/// have a translation, use the NearC convention. +static CallingConvention dwarfCCToCodeView(unsigned DwarfCC) { + switch (DwarfCC) { + case dwarf::DW_CC_normal: return CallingConvention::NearC; + case dwarf::DW_CC_BORLAND_msfastcall: return CallingConvention::NearFast; + case dwarf::DW_CC_BORLAND_thiscall: return CallingConvention::ThisCall; + case dwarf::DW_CC_BORLAND_stdcall: return CallingConvention::NearStdCall; + case dwarf::DW_CC_BORLAND_pascal: return CallingConvention::NearPascal; + case dwarf::DW_CC_LLVM_vectorcall: return CallingConvention::NearVector; + } + return CallingConvention::NearC; +} + +TypeIndex CodeViewDebug::lowerTypeModifier(const DIDerivedType *Ty) { + ModifierOptions Mods = ModifierOptions::None; + PointerOptions PO = PointerOptions::None; + bool IsModifier = true; + const DIType *BaseTy = Ty; + while (IsModifier && BaseTy) { + // FIXME: Need to add DWARF tags for __unaligned and _Atomic + switch (BaseTy->getTag()) { + case dwarf::DW_TAG_const_type: + Mods |= ModifierOptions::Const; + PO |= PointerOptions::Const; + break; + case dwarf::DW_TAG_volatile_type: + Mods |= ModifierOptions::Volatile; + PO |= PointerOptions::Volatile; + break; + case dwarf::DW_TAG_restrict_type: + // Only pointer types be marked with __restrict. There is no known flag + // for __restrict in LF_MODIFIER records. + PO |= PointerOptions::Restrict; + break; + default: + IsModifier = false; + break; + } + if (IsModifier) + BaseTy = cast<DIDerivedType>(BaseTy)->getBaseType(); + } + + // Check if the inner type will use an LF_POINTER record. If so, the + // qualifiers will go in the LF_POINTER record. This comes up for types like + // 'int *const' and 'int *__restrict', not the more common cases like 'const + // char *'. + if (BaseTy) { + switch (BaseTy->getTag()) { + case dwarf::DW_TAG_pointer_type: + case dwarf::DW_TAG_reference_type: + case dwarf::DW_TAG_rvalue_reference_type: + return lowerTypePointer(cast<DIDerivedType>(BaseTy), PO); + case dwarf::DW_TAG_ptr_to_member_type: + return lowerTypeMemberPointer(cast<DIDerivedType>(BaseTy), PO); + default: + break; + } + } + + TypeIndex ModifiedTI = getTypeIndex(BaseTy); + + // Return the base type index if there aren't any modifiers. For example, the + // metadata could contain restrict wrappers around non-pointer types. + if (Mods == ModifierOptions::None) + return ModifiedTI; + + ModifierRecord MR(ModifiedTI, Mods); + return TypeTable.writeLeafType(MR); +} + +TypeIndex CodeViewDebug::lowerTypeFunction(const DISubroutineType *Ty) { + SmallVector<TypeIndex, 8> ReturnAndArgTypeIndices; + for (const DIType *ArgType : Ty->getTypeArray()) + ReturnAndArgTypeIndices.push_back(getTypeIndex(ArgType)); + + // MSVC uses type none for variadic argument. + if (ReturnAndArgTypeIndices.size() > 1 && + ReturnAndArgTypeIndices.back() == TypeIndex::Void()) { + ReturnAndArgTypeIndices.back() = TypeIndex::None(); + } + TypeIndex ReturnTypeIndex = TypeIndex::Void(); + ArrayRef<TypeIndex> ArgTypeIndices = std::nullopt; + if (!ReturnAndArgTypeIndices.empty()) { + auto ReturnAndArgTypesRef = ArrayRef(ReturnAndArgTypeIndices); + ReturnTypeIndex = ReturnAndArgTypesRef.front(); + ArgTypeIndices = ReturnAndArgTypesRef.drop_front(); + } + + ArgListRecord ArgListRec(TypeRecordKind::ArgList, ArgTypeIndices); + TypeIndex ArgListIndex = TypeTable.writeLeafType(ArgListRec); + + CallingConvention CC = dwarfCCToCodeView(Ty->getCC()); + + FunctionOptions FO = getFunctionOptions(Ty); + ProcedureRecord Procedure(ReturnTypeIndex, CC, FO, ArgTypeIndices.size(), + ArgListIndex); + return TypeTable.writeLeafType(Procedure); +} + +TypeIndex CodeViewDebug::lowerTypeMemberFunction(const DISubroutineType *Ty, + const DIType *ClassTy, + int ThisAdjustment, + bool IsStaticMethod, + FunctionOptions FO) { + // Lower the containing class type. + TypeIndex ClassType = getTypeIndex(ClassTy); + + DITypeRefArray ReturnAndArgs = Ty->getTypeArray(); + + unsigned Index = 0; + SmallVector<TypeIndex, 8> ArgTypeIndices; + TypeIndex ReturnTypeIndex = TypeIndex::Void(); + if (ReturnAndArgs.size() > Index) { + ReturnTypeIndex = getTypeIndex(ReturnAndArgs[Index++]); + } + + // If the first argument is a pointer type and this isn't a static method, + // treat it as the special 'this' parameter, which is encoded separately from + // the arguments. + TypeIndex ThisTypeIndex; + if (!IsStaticMethod && ReturnAndArgs.size() > Index) { + if (const DIDerivedType *PtrTy = + dyn_cast_or_null<DIDerivedType>(ReturnAndArgs[Index])) { + if (PtrTy->getTag() == dwarf::DW_TAG_pointer_type) { + ThisTypeIndex = getTypeIndexForThisPtr(PtrTy, Ty); + Index++; + } + } + } + + while (Index < ReturnAndArgs.size()) + ArgTypeIndices.push_back(getTypeIndex(ReturnAndArgs[Index++])); + + // MSVC uses type none for variadic argument. + if (!ArgTypeIndices.empty() && ArgTypeIndices.back() == TypeIndex::Void()) + ArgTypeIndices.back() = TypeIndex::None(); + + ArgListRecord ArgListRec(TypeRecordKind::ArgList, ArgTypeIndices); + TypeIndex ArgListIndex = TypeTable.writeLeafType(ArgListRec); + + CallingConvention CC = dwarfCCToCodeView(Ty->getCC()); + + MemberFunctionRecord MFR(ReturnTypeIndex, ClassType, ThisTypeIndex, CC, FO, + ArgTypeIndices.size(), ArgListIndex, ThisAdjustment); + return TypeTable.writeLeafType(MFR); +} + +TypeIndex CodeViewDebug::lowerTypeVFTableShape(const DIDerivedType *Ty) { + unsigned VSlotCount = + Ty->getSizeInBits() / (8 * Asm->MAI->getCodePointerSize()); + SmallVector<VFTableSlotKind, 4> Slots(VSlotCount, VFTableSlotKind::Near); + + VFTableShapeRecord VFTSR(Slots); + return TypeTable.writeLeafType(VFTSR); +} + +static MemberAccess translateAccessFlags(unsigned RecordTag, unsigned Flags) { + switch (Flags & DINode::FlagAccessibility) { + case DINode::FlagPrivate: return MemberAccess::Private; + case DINode::FlagPublic: return MemberAccess::Public; + case DINode::FlagProtected: return MemberAccess::Protected; + case 0: + // If there was no explicit access control, provide the default for the tag. + return RecordTag == dwarf::DW_TAG_class_type ? MemberAccess::Private + : MemberAccess::Public; + } + llvm_unreachable("access flags are exclusive"); +} + +static MethodOptions translateMethodOptionFlags(const DISubprogram *SP) { + if (SP->isArtificial()) + return MethodOptions::CompilerGenerated; + + // FIXME: Handle other MethodOptions. + + return MethodOptions::None; +} + +static MethodKind translateMethodKindFlags(const DISubprogram *SP, + bool Introduced) { + if (SP->getFlags() & DINode::FlagStaticMember) + return MethodKind::Static; + + switch (SP->getVirtuality()) { + case dwarf::DW_VIRTUALITY_none: + break; + case dwarf::DW_VIRTUALITY_virtual: + return Introduced ? MethodKind::IntroducingVirtual : MethodKind::Virtual; + case dwarf::DW_VIRTUALITY_pure_virtual: + return Introduced ? MethodKind::PureIntroducingVirtual + : MethodKind::PureVirtual; + default: + llvm_unreachable("unhandled virtuality case"); + } + + return MethodKind::Vanilla; +} + +static TypeRecordKind getRecordKind(const DICompositeType *Ty) { + switch (Ty->getTag()) { + case dwarf::DW_TAG_class_type: + return TypeRecordKind::Class; + case dwarf::DW_TAG_structure_type: + return TypeRecordKind::Struct; + default: + llvm_unreachable("unexpected tag"); + } +} + +/// Return ClassOptions that should be present on both the forward declaration +/// and the defintion of a tag type. +static ClassOptions getCommonClassOptions(const DICompositeType *Ty) { + ClassOptions CO = ClassOptions::None; + + // MSVC always sets this flag, even for local types. Clang doesn't always + // appear to give every type a linkage name, which may be problematic for us. + // FIXME: Investigate the consequences of not following them here. + if (!Ty->getIdentifier().empty()) + CO |= ClassOptions::HasUniqueName; + + // Put the Nested flag on a type if it appears immediately inside a tag type. + // Do not walk the scope chain. Do not attempt to compute ContainsNestedClass + // here. That flag is only set on definitions, and not forward declarations. + const DIScope *ImmediateScope = Ty->getScope(); + if (ImmediateScope && isa<DICompositeType>(ImmediateScope)) + CO |= ClassOptions::Nested; + + // Put the Scoped flag on function-local types. MSVC puts this flag for enum + // type only when it has an immediate function scope. Clang never puts enums + // inside DILexicalBlock scopes. Enum types, as generated by clang, are + // always in function, class, or file scopes. + if (Ty->getTag() == dwarf::DW_TAG_enumeration_type) { + if (ImmediateScope && isa<DISubprogram>(ImmediateScope)) + CO |= ClassOptions::Scoped; + } else { + for (const DIScope *Scope = ImmediateScope; Scope != nullptr; + Scope = Scope->getScope()) { + if (isa<DISubprogram>(Scope)) { + CO |= ClassOptions::Scoped; + break; + } + } + } + + return CO; +} + +void CodeViewDebug::addUDTSrcLine(const DIType *Ty, TypeIndex TI) { + switch (Ty->getTag()) { + case dwarf::DW_TAG_class_type: + case dwarf::DW_TAG_structure_type: + case dwarf::DW_TAG_union_type: + case dwarf::DW_TAG_enumeration_type: + break; + default: + return; + } + + if (const auto *File = Ty->getFile()) { + StringIdRecord SIDR(TypeIndex(0x0), getFullFilepath(File)); + TypeIndex SIDI = TypeTable.writeLeafType(SIDR); + + UdtSourceLineRecord USLR(TI, SIDI, Ty->getLine()); + TypeTable.writeLeafType(USLR); + } +} + +TypeIndex CodeViewDebug::lowerTypeEnum(const DICompositeType *Ty) { + ClassOptions CO = getCommonClassOptions(Ty); + TypeIndex FTI; + unsigned EnumeratorCount = 0; + + if (Ty->isForwardDecl()) { + CO |= ClassOptions::ForwardReference; + } else { + ContinuationRecordBuilder ContinuationBuilder; + ContinuationBuilder.begin(ContinuationRecordKind::FieldList); + for (const DINode *Element : Ty->getElements()) { + // We assume that the frontend provides all members in source declaration + // order, which is what MSVC does. + if (auto *Enumerator = dyn_cast_or_null<DIEnumerator>(Element)) { + // FIXME: Is it correct to always emit these as unsigned here? + EnumeratorRecord ER(MemberAccess::Public, + APSInt(Enumerator->getValue(), true), + Enumerator->getName()); + ContinuationBuilder.writeMemberType(ER); + EnumeratorCount++; + } + } + FTI = TypeTable.insertRecord(ContinuationBuilder); + } + + std::string FullName = getFullyQualifiedName(Ty); + + EnumRecord ER(EnumeratorCount, CO, FTI, FullName, Ty->getIdentifier(), + getTypeIndex(Ty->getBaseType())); + TypeIndex EnumTI = TypeTable.writeLeafType(ER); + + addUDTSrcLine(Ty, EnumTI); + + return EnumTI; +} + +//===----------------------------------------------------------------------===// +// ClassInfo +//===----------------------------------------------------------------------===// + +struct llvm::ClassInfo { + struct MemberInfo { + const DIDerivedType *MemberTypeNode; + uint64_t BaseOffset; + }; + // [MemberInfo] + using MemberList = std::vector<MemberInfo>; + + using MethodsList = TinyPtrVector<const DISubprogram *>; + // MethodName -> MethodsList + using MethodsMap = MapVector<MDString *, MethodsList>; + + /// Base classes. + std::vector<const DIDerivedType *> Inheritance; + + /// Direct members. + MemberList Members; + // Direct overloaded methods gathered by name. + MethodsMap Methods; + + TypeIndex VShapeTI; + + std::vector<const DIType *> NestedTypes; +}; + +void CodeViewDebug::clear() { + assert(CurFn == nullptr); + FileIdMap.clear(); + FnDebugInfo.clear(); + FileToFilepathMap.clear(); + LocalUDTs.clear(); + GlobalUDTs.clear(); + TypeIndices.clear(); + CompleteTypeIndices.clear(); + ScopeGlobals.clear(); + CVGlobalVariableOffsets.clear(); +} + +void CodeViewDebug::collectMemberInfo(ClassInfo &Info, + const DIDerivedType *DDTy) { + if (!DDTy->getName().empty()) { + Info.Members.push_back({DDTy, 0}); + + // Collect static const data members with values. + if ((DDTy->getFlags() & DINode::FlagStaticMember) == + DINode::FlagStaticMember) { + if (DDTy->getConstant() && (isa<ConstantInt>(DDTy->getConstant()) || + isa<ConstantFP>(DDTy->getConstant()))) + StaticConstMembers.push_back(DDTy); + } + + return; + } + + // An unnamed member may represent a nested struct or union. Attempt to + // interpret the unnamed member as a DICompositeType possibly wrapped in + // qualifier types. Add all the indirect fields to the current record if that + // succeeds, and drop the member if that fails. + assert((DDTy->getOffsetInBits() % 8) == 0 && "Unnamed bitfield member!"); + uint64_t Offset = DDTy->getOffsetInBits(); + const DIType *Ty = DDTy->getBaseType(); + bool FullyResolved = false; + while (!FullyResolved) { + switch (Ty->getTag()) { + case dwarf::DW_TAG_const_type: + case dwarf::DW_TAG_volatile_type: + // FIXME: we should apply the qualifier types to the indirect fields + // rather than dropping them. + Ty = cast<DIDerivedType>(Ty)->getBaseType(); + break; + default: + FullyResolved = true; + break; + } + } + + const DICompositeType *DCTy = dyn_cast<DICompositeType>(Ty); + if (!DCTy) + return; + + ClassInfo NestedInfo = collectClassInfo(DCTy); + for (const ClassInfo::MemberInfo &IndirectField : NestedInfo.Members) + Info.Members.push_back( + {IndirectField.MemberTypeNode, IndirectField.BaseOffset + Offset}); +} + +ClassInfo CodeViewDebug::collectClassInfo(const DICompositeType *Ty) { + ClassInfo Info; + // Add elements to structure type. + DINodeArray Elements = Ty->getElements(); + for (auto *Element : Elements) { + // We assume that the frontend provides all members in source declaration + // order, which is what MSVC does. + if (!Element) + continue; + if (auto *SP = dyn_cast<DISubprogram>(Element)) { + Info.Methods[SP->getRawName()].push_back(SP); + } else if (auto *DDTy = dyn_cast<DIDerivedType>(Element)) { + if (DDTy->getTag() == dwarf::DW_TAG_member) { + collectMemberInfo(Info, DDTy); + } else if (DDTy->getTag() == dwarf::DW_TAG_inheritance) { + Info.Inheritance.push_back(DDTy); + } else if (DDTy->getTag() == dwarf::DW_TAG_pointer_type && + DDTy->getName() == "__vtbl_ptr_type") { + Info.VShapeTI = getTypeIndex(DDTy); + } else if (DDTy->getTag() == dwarf::DW_TAG_typedef) { + Info.NestedTypes.push_back(DDTy); + } else if (DDTy->getTag() == dwarf::DW_TAG_friend) { + // Ignore friend members. It appears that MSVC emitted info about + // friends in the past, but modern versions do not. + } + } else if (auto *Composite = dyn_cast<DICompositeType>(Element)) { + Info.NestedTypes.push_back(Composite); + } + // Skip other unrecognized kinds of elements. + } + return Info; +} + +static bool shouldAlwaysEmitCompleteClassType(const DICompositeType *Ty) { + // This routine is used by lowerTypeClass and lowerTypeUnion to determine + // if a complete type should be emitted instead of a forward reference. + return Ty->getName().empty() && Ty->getIdentifier().empty() && + !Ty->isForwardDecl(); +} + +TypeIndex CodeViewDebug::lowerTypeClass(const DICompositeType *Ty) { + // Emit the complete type for unnamed structs. C++ classes with methods + // which have a circular reference back to the class type are expected to + // be named by the front-end and should not be "unnamed". C unnamed + // structs should not have circular references. + if (shouldAlwaysEmitCompleteClassType(Ty)) { + // If this unnamed complete type is already in the process of being defined + // then the description of the type is malformed and cannot be emitted + // into CodeView correctly so report a fatal error. + auto I = CompleteTypeIndices.find(Ty); + if (I != CompleteTypeIndices.end() && I->second == TypeIndex()) + report_fatal_error("cannot debug circular reference to unnamed type"); + return getCompleteTypeIndex(Ty); + } + + // First, construct the forward decl. Don't look into Ty to compute the + // forward decl options, since it might not be available in all TUs. + TypeRecordKind Kind = getRecordKind(Ty); + ClassOptions CO = + ClassOptions::ForwardReference | getCommonClassOptions(Ty); + std::string FullName = getFullyQualifiedName(Ty); + ClassRecord CR(Kind, 0, CO, TypeIndex(), TypeIndex(), TypeIndex(), 0, + FullName, Ty->getIdentifier()); + TypeIndex FwdDeclTI = TypeTable.writeLeafType(CR); + if (!Ty->isForwardDecl()) + DeferredCompleteTypes.push_back(Ty); + return FwdDeclTI; +} + +TypeIndex CodeViewDebug::lowerCompleteTypeClass(const DICompositeType *Ty) { + // Construct the field list and complete type record. + TypeRecordKind Kind = getRecordKind(Ty); + ClassOptions CO = getCommonClassOptions(Ty); + TypeIndex FieldTI; + TypeIndex VShapeTI; + unsigned FieldCount; + bool ContainsNestedClass; + std::tie(FieldTI, VShapeTI, FieldCount, ContainsNestedClass) = + lowerRecordFieldList(Ty); + + if (ContainsNestedClass) + CO |= ClassOptions::ContainsNestedClass; + + // MSVC appears to set this flag by searching any destructor or method with + // FunctionOptions::Constructor among the emitted members. Clang AST has all + // the members, however special member functions are not yet emitted into + // debug information. For now checking a class's non-triviality seems enough. + // FIXME: not true for a nested unnamed struct. + if (isNonTrivial(Ty)) + CO |= ClassOptions::HasConstructorOrDestructor; + + std::string FullName = getFullyQualifiedName(Ty); + + uint64_t SizeInBytes = Ty->getSizeInBits() / 8; + + ClassRecord CR(Kind, FieldCount, CO, FieldTI, TypeIndex(), VShapeTI, + SizeInBytes, FullName, Ty->getIdentifier()); + TypeIndex ClassTI = TypeTable.writeLeafType(CR); + + addUDTSrcLine(Ty, ClassTI); + + addToUDTs(Ty); + + return ClassTI; +} + +TypeIndex CodeViewDebug::lowerTypeUnion(const DICompositeType *Ty) { + // Emit the complete type for unnamed unions. + if (shouldAlwaysEmitCompleteClassType(Ty)) + return getCompleteTypeIndex(Ty); + + ClassOptions CO = + ClassOptions::ForwardReference | getCommonClassOptions(Ty); + std::string FullName = getFullyQualifiedName(Ty); + UnionRecord UR(0, CO, TypeIndex(), 0, FullName, Ty->getIdentifier()); + TypeIndex FwdDeclTI = TypeTable.writeLeafType(UR); + if (!Ty->isForwardDecl()) + DeferredCompleteTypes.push_back(Ty); + return FwdDeclTI; +} + +TypeIndex CodeViewDebug::lowerCompleteTypeUnion(const DICompositeType *Ty) { + ClassOptions CO = ClassOptions::Sealed | getCommonClassOptions(Ty); + TypeIndex FieldTI; + unsigned FieldCount; + bool ContainsNestedClass; + std::tie(FieldTI, std::ignore, FieldCount, ContainsNestedClass) = + lowerRecordFieldList(Ty); + + if (ContainsNestedClass) + CO |= ClassOptions::ContainsNestedClass; + + uint64_t SizeInBytes = Ty->getSizeInBits() / 8; + std::string FullName = getFullyQualifiedName(Ty); + + UnionRecord UR(FieldCount, CO, FieldTI, SizeInBytes, FullName, + Ty->getIdentifier()); + TypeIndex UnionTI = TypeTable.writeLeafType(UR); + + addUDTSrcLine(Ty, UnionTI); + + addToUDTs(Ty); + + return UnionTI; +} + +std::tuple<TypeIndex, TypeIndex, unsigned, bool> +CodeViewDebug::lowerRecordFieldList(const DICompositeType *Ty) { + // Manually count members. MSVC appears to count everything that generates a + // field list record. Each individual overload in a method overload group + // contributes to this count, even though the overload group is a single field + // list record. + unsigned MemberCount = 0; + ClassInfo Info = collectClassInfo(Ty); + ContinuationRecordBuilder ContinuationBuilder; + ContinuationBuilder.begin(ContinuationRecordKind::FieldList); + + // Create base classes. + for (const DIDerivedType *I : Info.Inheritance) { + if (I->getFlags() & DINode::FlagVirtual) { + // Virtual base. + unsigned VBPtrOffset = I->getVBPtrOffset(); + // FIXME: Despite the accessor name, the offset is really in bytes. + unsigned VBTableIndex = I->getOffsetInBits() / 4; + auto RecordKind = (I->getFlags() & DINode::FlagIndirectVirtualBase) == DINode::FlagIndirectVirtualBase + ? TypeRecordKind::IndirectVirtualBaseClass + : TypeRecordKind::VirtualBaseClass; + VirtualBaseClassRecord VBCR( + RecordKind, translateAccessFlags(Ty->getTag(), I->getFlags()), + getTypeIndex(I->getBaseType()), getVBPTypeIndex(), VBPtrOffset, + VBTableIndex); + + ContinuationBuilder.writeMemberType(VBCR); + MemberCount++; + } else { + assert(I->getOffsetInBits() % 8 == 0 && + "bases must be on byte boundaries"); + BaseClassRecord BCR(translateAccessFlags(Ty->getTag(), I->getFlags()), + getTypeIndex(I->getBaseType()), + I->getOffsetInBits() / 8); + ContinuationBuilder.writeMemberType(BCR); + MemberCount++; + } + } + + // Create members. + for (ClassInfo::MemberInfo &MemberInfo : Info.Members) { + const DIDerivedType *Member = MemberInfo.MemberTypeNode; + TypeIndex MemberBaseType = getTypeIndex(Member->getBaseType()); + StringRef MemberName = Member->getName(); + MemberAccess Access = + translateAccessFlags(Ty->getTag(), Member->getFlags()); + + if (Member->isStaticMember()) { + StaticDataMemberRecord SDMR(Access, MemberBaseType, MemberName); + ContinuationBuilder.writeMemberType(SDMR); + MemberCount++; + continue; + } + + // Virtual function pointer member. + if ((Member->getFlags() & DINode::FlagArtificial) && + Member->getName().startswith("_vptr$")) { + VFPtrRecord VFPR(getTypeIndex(Member->getBaseType())); + ContinuationBuilder.writeMemberType(VFPR); + MemberCount++; + continue; + } + + // Data member. + uint64_t MemberOffsetInBits = + Member->getOffsetInBits() + MemberInfo.BaseOffset; + if (Member->isBitField()) { + uint64_t StartBitOffset = MemberOffsetInBits; + if (const auto *CI = + dyn_cast_or_null<ConstantInt>(Member->getStorageOffsetInBits())) { + MemberOffsetInBits = CI->getZExtValue() + MemberInfo.BaseOffset; + } + StartBitOffset -= MemberOffsetInBits; + BitFieldRecord BFR(MemberBaseType, Member->getSizeInBits(), + StartBitOffset); + MemberBaseType = TypeTable.writeLeafType(BFR); + } + uint64_t MemberOffsetInBytes = MemberOffsetInBits / 8; + DataMemberRecord DMR(Access, MemberBaseType, MemberOffsetInBytes, + MemberName); + ContinuationBuilder.writeMemberType(DMR); + MemberCount++; + } + + // Create methods + for (auto &MethodItr : Info.Methods) { + StringRef Name = MethodItr.first->getString(); + + std::vector<OneMethodRecord> Methods; + for (const DISubprogram *SP : MethodItr.second) { + TypeIndex MethodType = getMemberFunctionType(SP, Ty); + bool Introduced = SP->getFlags() & DINode::FlagIntroducedVirtual; + + unsigned VFTableOffset = -1; + if (Introduced) + VFTableOffset = SP->getVirtualIndex() * getPointerSizeInBytes(); + + Methods.push_back(OneMethodRecord( + MethodType, translateAccessFlags(Ty->getTag(), SP->getFlags()), + translateMethodKindFlags(SP, Introduced), + translateMethodOptionFlags(SP), VFTableOffset, Name)); + MemberCount++; + } + assert(!Methods.empty() && "Empty methods map entry"); + if (Methods.size() == 1) + ContinuationBuilder.writeMemberType(Methods[0]); + else { + // FIXME: Make this use its own ContinuationBuilder so that + // MethodOverloadList can be split correctly. + MethodOverloadListRecord MOLR(Methods); + TypeIndex MethodList = TypeTable.writeLeafType(MOLR); + + OverloadedMethodRecord OMR(Methods.size(), MethodList, Name); + ContinuationBuilder.writeMemberType(OMR); + } + } + + // Create nested classes. + for (const DIType *Nested : Info.NestedTypes) { + NestedTypeRecord R(getTypeIndex(Nested), Nested->getName()); + ContinuationBuilder.writeMemberType(R); + MemberCount++; + } + + TypeIndex FieldTI = TypeTable.insertRecord(ContinuationBuilder); + return std::make_tuple(FieldTI, Info.VShapeTI, MemberCount, + !Info.NestedTypes.empty()); +} + +TypeIndex CodeViewDebug::getVBPTypeIndex() { + if (!VBPType.getIndex()) { + // Make a 'const int *' type. + ModifierRecord MR(TypeIndex::Int32(), ModifierOptions::Const); + TypeIndex ModifiedTI = TypeTable.writeLeafType(MR); + + PointerKind PK = getPointerSizeInBytes() == 8 ? PointerKind::Near64 + : PointerKind::Near32; + PointerMode PM = PointerMode::Pointer; + PointerOptions PO = PointerOptions::None; + PointerRecord PR(ModifiedTI, PK, PM, PO, getPointerSizeInBytes()); + VBPType = TypeTable.writeLeafType(PR); + } + + return VBPType; +} + +TypeIndex CodeViewDebug::getTypeIndex(const DIType *Ty, const DIType *ClassTy) { + // The null DIType is the void type. Don't try to hash it. + if (!Ty) + return TypeIndex::Void(); + + // Check if we've already translated this type. Don't try to do a + // get-or-create style insertion that caches the hash lookup across the + // lowerType call. It will update the TypeIndices map. + auto I = TypeIndices.find({Ty, ClassTy}); + if (I != TypeIndices.end()) + return I->second; + + TypeLoweringScope S(*this); + TypeIndex TI = lowerType(Ty, ClassTy); + return recordTypeIndexForDINode(Ty, TI, ClassTy); +} + +codeview::TypeIndex +CodeViewDebug::getTypeIndexForThisPtr(const DIDerivedType *PtrTy, + const DISubroutineType *SubroutineTy) { + assert(PtrTy->getTag() == dwarf::DW_TAG_pointer_type && + "this type must be a pointer type"); + + PointerOptions Options = PointerOptions::None; + if (SubroutineTy->getFlags() & DINode::DIFlags::FlagLValueReference) + Options = PointerOptions::LValueRefThisPointer; + else if (SubroutineTy->getFlags() & DINode::DIFlags::FlagRValueReference) + Options = PointerOptions::RValueRefThisPointer; + + // Check if we've already translated this type. If there is no ref qualifier + // on the function then we look up this pointer type with no associated class + // so that the TypeIndex for the this pointer can be shared with the type + // index for other pointers to this class type. If there is a ref qualifier + // then we lookup the pointer using the subroutine as the parent type. + auto I = TypeIndices.find({PtrTy, SubroutineTy}); + if (I != TypeIndices.end()) + return I->second; + + TypeLoweringScope S(*this); + TypeIndex TI = lowerTypePointer(PtrTy, Options); + return recordTypeIndexForDINode(PtrTy, TI, SubroutineTy); +} + +TypeIndex CodeViewDebug::getTypeIndexForReferenceTo(const DIType *Ty) { + PointerRecord PR(getTypeIndex(Ty), + getPointerSizeInBytes() == 8 ? PointerKind::Near64 + : PointerKind::Near32, + PointerMode::LValueReference, PointerOptions::None, + Ty->getSizeInBits() / 8); + return TypeTable.writeLeafType(PR); +} + +TypeIndex CodeViewDebug::getCompleteTypeIndex(const DIType *Ty) { + // The null DIType is the void type. Don't try to hash it. + if (!Ty) + return TypeIndex::Void(); + + // Look through typedefs when getting the complete type index. Call + // getTypeIndex on the typdef to ensure that any UDTs are accumulated and are + // emitted only once. + if (Ty->getTag() == dwarf::DW_TAG_typedef) + (void)getTypeIndex(Ty); + while (Ty->getTag() == dwarf::DW_TAG_typedef) + Ty = cast<DIDerivedType>(Ty)->getBaseType(); + + // If this is a non-record type, the complete type index is the same as the + // normal type index. Just call getTypeIndex. + switch (Ty->getTag()) { + case dwarf::DW_TAG_class_type: + case dwarf::DW_TAG_structure_type: + case dwarf::DW_TAG_union_type: + break; + default: + return getTypeIndex(Ty); + } + + const auto *CTy = cast<DICompositeType>(Ty); + + TypeLoweringScope S(*this); + + // Make sure the forward declaration is emitted first. It's unclear if this + // is necessary, but MSVC does it, and we should follow suit until we can show + // otherwise. + // We only emit a forward declaration for named types. + if (!CTy->getName().empty() || !CTy->getIdentifier().empty()) { + TypeIndex FwdDeclTI = getTypeIndex(CTy); + + // Just use the forward decl if we don't have complete type info. This + // might happen if the frontend is using modules and expects the complete + // definition to be emitted elsewhere. + if (CTy->isForwardDecl()) + return FwdDeclTI; + } + + // Check if we've already translated the complete record type. + // Insert the type with a null TypeIndex to signify that the type is currently + // being lowered. + auto InsertResult = CompleteTypeIndices.insert({CTy, TypeIndex()}); + if (!InsertResult.second) + return InsertResult.first->second; + + TypeIndex TI; + switch (CTy->getTag()) { + case dwarf::DW_TAG_class_type: + case dwarf::DW_TAG_structure_type: + TI = lowerCompleteTypeClass(CTy); + break; + case dwarf::DW_TAG_union_type: + TI = lowerCompleteTypeUnion(CTy); + break; + default: + llvm_unreachable("not a record"); + } + + // Update the type index associated with this CompositeType. This cannot + // use the 'InsertResult' iterator above because it is potentially + // invalidated by map insertions which can occur while lowering the class + // type above. + CompleteTypeIndices[CTy] = TI; + return TI; +} + +/// Emit all the deferred complete record types. Try to do this in FIFO order, +/// and do this until fixpoint, as each complete record type typically +/// references +/// many other record types. +void CodeViewDebug::emitDeferredCompleteTypes() { + SmallVector<const DICompositeType *, 4> TypesToEmit; + while (!DeferredCompleteTypes.empty()) { + std::swap(DeferredCompleteTypes, TypesToEmit); + for (const DICompositeType *RecordTy : TypesToEmit) + getCompleteTypeIndex(RecordTy); + TypesToEmit.clear(); + } +} + +void CodeViewDebug::emitLocalVariableList(const FunctionInfo &FI, + ArrayRef<LocalVariable> Locals) { + // Get the sorted list of parameters and emit them first. + SmallVector<const LocalVariable *, 6> Params; + for (const LocalVariable &L : Locals) + if (L.DIVar->isParameter()) + Params.push_back(&L); + llvm::sort(Params, [](const LocalVariable *L, const LocalVariable *R) { + return L->DIVar->getArg() < R->DIVar->getArg(); + }); + for (const LocalVariable *L : Params) + emitLocalVariable(FI, *L); + + // Next emit all non-parameters in the order that we found them. + for (const LocalVariable &L : Locals) { + if (!L.DIVar->isParameter()) { + if (L.ConstantValue) { + // If ConstantValue is set we will emit it as a S_CONSTANT instead of a + // S_LOCAL in order to be able to represent it at all. + const DIType *Ty = L.DIVar->getType(); + APSInt Val(*L.ConstantValue); + emitConstantSymbolRecord(Ty, Val, std::string(L.DIVar->getName())); + } else { + emitLocalVariable(FI, L); + } + } + } +} + +void CodeViewDebug::emitLocalVariable(const FunctionInfo &FI, + const LocalVariable &Var) { + // LocalSym record, see SymbolRecord.h for more info. + MCSymbol *LocalEnd = beginSymbolRecord(SymbolKind::S_LOCAL); + + LocalSymFlags Flags = LocalSymFlags::None; + if (Var.DIVar->isParameter()) + Flags |= LocalSymFlags::IsParameter; + if (Var.DefRanges.empty()) + Flags |= LocalSymFlags::IsOptimizedOut; + + OS.AddComment("TypeIndex"); + TypeIndex TI = Var.UseReferenceType + ? getTypeIndexForReferenceTo(Var.DIVar->getType()) + : getCompleteTypeIndex(Var.DIVar->getType()); + OS.emitInt32(TI.getIndex()); + OS.AddComment("Flags"); + OS.emitInt16(static_cast<uint16_t>(Flags)); + // Truncate the name so we won't overflow the record length field. + emitNullTerminatedSymbolName(OS, Var.DIVar->getName()); + endSymbolRecord(LocalEnd); + + // Calculate the on disk prefix of the appropriate def range record. The + // records and on disk formats are described in SymbolRecords.h. BytePrefix + // should be big enough to hold all forms without memory allocation. + SmallString<20> BytePrefix; + for (const auto &Pair : Var.DefRanges) { + LocalVarDef DefRange = Pair.first; + const auto &Ranges = Pair.second; + BytePrefix.clear(); + if (DefRange.InMemory) { + int Offset = DefRange.DataOffset; + unsigned Reg = DefRange.CVRegister; + + // 32-bit x86 call sequences often use PUSH instructions, which disrupt + // ESP-relative offsets. Use the virtual frame pointer, VFRAME or $T0, + // instead. In frames without stack realignment, $T0 will be the CFA. + if (RegisterId(Reg) == RegisterId::ESP) { + Reg = unsigned(RegisterId::VFRAME); + Offset += FI.OffsetAdjustment; + } + + // If we can use the chosen frame pointer for the frame and this isn't a + // sliced aggregate, use the smaller S_DEFRANGE_FRAMEPOINTER_REL record. + // Otherwise, use S_DEFRANGE_REGISTER_REL. + EncodedFramePtrReg EncFP = encodeFramePtrReg(RegisterId(Reg), TheCPU); + if (!DefRange.IsSubfield && EncFP != EncodedFramePtrReg::None && + (bool(Flags & LocalSymFlags::IsParameter) + ? (EncFP == FI.EncodedParamFramePtrReg) + : (EncFP == FI.EncodedLocalFramePtrReg))) { + DefRangeFramePointerRelHeader DRHdr; + DRHdr.Offset = Offset; + OS.emitCVDefRangeDirective(Ranges, DRHdr); + } else { + uint16_t RegRelFlags = 0; + if (DefRange.IsSubfield) { + RegRelFlags = DefRangeRegisterRelSym::IsSubfieldFlag | + (DefRange.StructOffset + << DefRangeRegisterRelSym::OffsetInParentShift); + } + DefRangeRegisterRelHeader DRHdr; + DRHdr.Register = Reg; + DRHdr.Flags = RegRelFlags; + DRHdr.BasePointerOffset = Offset; + OS.emitCVDefRangeDirective(Ranges, DRHdr); + } + } else { + assert(DefRange.DataOffset == 0 && "unexpected offset into register"); + if (DefRange.IsSubfield) { + DefRangeSubfieldRegisterHeader DRHdr; + DRHdr.Register = DefRange.CVRegister; + DRHdr.MayHaveNoName = 0; + DRHdr.OffsetInParent = DefRange.StructOffset; + OS.emitCVDefRangeDirective(Ranges, DRHdr); + } else { + DefRangeRegisterHeader DRHdr; + DRHdr.Register = DefRange.CVRegister; + DRHdr.MayHaveNoName = 0; + OS.emitCVDefRangeDirective(Ranges, DRHdr); + } + } + } +} + +void CodeViewDebug::emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks, + const FunctionInfo& FI) { + for (LexicalBlock *Block : Blocks) + emitLexicalBlock(*Block, FI); +} + +/// Emit an S_BLOCK32 and S_END record pair delimiting the contents of a +/// lexical block scope. +void CodeViewDebug::emitLexicalBlock(const LexicalBlock &Block, + const FunctionInfo& FI) { + MCSymbol *RecordEnd = beginSymbolRecord(SymbolKind::S_BLOCK32); + OS.AddComment("PtrParent"); + OS.emitInt32(0); // PtrParent + OS.AddComment("PtrEnd"); + OS.emitInt32(0); // PtrEnd + OS.AddComment("Code size"); + OS.emitAbsoluteSymbolDiff(Block.End, Block.Begin, 4); // Code Size + OS.AddComment("Function section relative address"); + OS.emitCOFFSecRel32(Block.Begin, /*Offset=*/0); // Func Offset + OS.AddComment("Function section index"); + OS.emitCOFFSectionIndex(FI.Begin); // Func Symbol + OS.AddComment("Lexical block name"); + emitNullTerminatedSymbolName(OS, Block.Name); // Name + endSymbolRecord(RecordEnd); + + // Emit variables local to this lexical block. + emitLocalVariableList(FI, Block.Locals); + emitGlobalVariableList(Block.Globals); + + // Emit lexical blocks contained within this block. + emitLexicalBlockList(Block.Children, FI); + + // Close the lexical block scope. + emitEndSymbolRecord(SymbolKind::S_END); +} + +/// Convenience routine for collecting lexical block information for a list +/// of lexical scopes. +void CodeViewDebug::collectLexicalBlockInfo( + SmallVectorImpl<LexicalScope *> &Scopes, + SmallVectorImpl<LexicalBlock *> &Blocks, + SmallVectorImpl<LocalVariable> &Locals, + SmallVectorImpl<CVGlobalVariable> &Globals) { + for (LexicalScope *Scope : Scopes) + collectLexicalBlockInfo(*Scope, Blocks, Locals, Globals); +} + +/// Populate the lexical blocks and local variable lists of the parent with +/// information about the specified lexical scope. +void CodeViewDebug::collectLexicalBlockInfo( + LexicalScope &Scope, + SmallVectorImpl<LexicalBlock *> &ParentBlocks, + SmallVectorImpl<LocalVariable> &ParentLocals, + SmallVectorImpl<CVGlobalVariable> &ParentGlobals) { + if (Scope.isAbstractScope()) + return; + + // Gather information about the lexical scope including local variables, + // global variables, and address ranges. + bool IgnoreScope = false; + auto LI = ScopeVariables.find(&Scope); + SmallVectorImpl<LocalVariable> *Locals = + LI != ScopeVariables.end() ? &LI->second : nullptr; + auto GI = ScopeGlobals.find(Scope.getScopeNode()); + SmallVectorImpl<CVGlobalVariable> *Globals = + GI != ScopeGlobals.end() ? GI->second.get() : nullptr; + const DILexicalBlock *DILB = dyn_cast<DILexicalBlock>(Scope.getScopeNode()); + const SmallVectorImpl<InsnRange> &Ranges = Scope.getRanges(); + + // Ignore lexical scopes which do not contain variables. + if (!Locals && !Globals) + IgnoreScope = true; + + // Ignore lexical scopes which are not lexical blocks. + if (!DILB) + IgnoreScope = true; + + // Ignore scopes which have too many address ranges to represent in the + // current CodeView format or do not have a valid address range. + // + // For lexical scopes with multiple address ranges you may be tempted to + // construct a single range covering every instruction where the block is + // live and everything in between. Unfortunately, Visual Studio only + // displays variables from the first matching lexical block scope. If the + // first lexical block contains exception handling code or cold code which + // is moved to the bottom of the routine creating a single range covering + // nearly the entire routine, then it will hide all other lexical blocks + // and the variables they contain. + if (Ranges.size() != 1 || !getLabelAfterInsn(Ranges.front().second)) + IgnoreScope = true; + + if (IgnoreScope) { + // This scope can be safely ignored and eliminating it will reduce the + // size of the debug information. Be sure to collect any variable and scope + // information from the this scope or any of its children and collapse them + // into the parent scope. + if (Locals) + ParentLocals.append(Locals->begin(), Locals->end()); + if (Globals) + ParentGlobals.append(Globals->begin(), Globals->end()); + collectLexicalBlockInfo(Scope.getChildren(), + ParentBlocks, + ParentLocals, + ParentGlobals); + return; + } + + // Create a new CodeView lexical block for this lexical scope. If we've + // seen this DILexicalBlock before then the scope tree is malformed and + // we can handle this gracefully by not processing it a second time. + auto BlockInsertion = CurFn->LexicalBlocks.insert({DILB, LexicalBlock()}); + if (!BlockInsertion.second) + return; + + // Create a lexical block containing the variables and collect the the + // lexical block information for the children. + const InsnRange &Range = Ranges.front(); + assert(Range.first && Range.second); + LexicalBlock &Block = BlockInsertion.first->second; + Block.Begin = getLabelBeforeInsn(Range.first); + Block.End = getLabelAfterInsn(Range.second); + assert(Block.Begin && "missing label for scope begin"); + assert(Block.End && "missing label for scope end"); + Block.Name = DILB->getName(); + if (Locals) + Block.Locals = std::move(*Locals); + if (Globals) + Block.Globals = std::move(*Globals); + ParentBlocks.push_back(&Block); + collectLexicalBlockInfo(Scope.getChildren(), + Block.Children, + Block.Locals, + Block.Globals); +} + +void CodeViewDebug::endFunctionImpl(const MachineFunction *MF) { + const Function &GV = MF->getFunction(); + assert(FnDebugInfo.count(&GV)); + assert(CurFn == FnDebugInfo[&GV].get()); + + collectVariableInfo(GV.getSubprogram()); + + // Build the lexical block structure to emit for this routine. + if (LexicalScope *CFS = LScopes.getCurrentFunctionScope()) + collectLexicalBlockInfo(*CFS, + CurFn->ChildBlocks, + CurFn->Locals, + CurFn->Globals); + + // Clear the scope and variable information from the map which will not be + // valid after we have finished processing this routine. This also prepares + // the map for the subsequent routine. + ScopeVariables.clear(); + + // Don't emit anything if we don't have any line tables. + // Thunks are compiler-generated and probably won't have source correlation. + if (!CurFn->HaveLineInfo && !GV.getSubprogram()->isThunk()) { + FnDebugInfo.erase(&GV); + CurFn = nullptr; + return; + } + + // Find heap alloc sites and add to list. + for (const auto &MBB : *MF) { + for (const auto &MI : MBB) { + if (MDNode *MD = MI.getHeapAllocMarker()) { + CurFn->HeapAllocSites.push_back(std::make_tuple(getLabelBeforeInsn(&MI), + getLabelAfterInsn(&MI), + dyn_cast<DIType>(MD))); + } + } + } + + CurFn->Annotations = MF->getCodeViewAnnotations(); + + CurFn->End = Asm->getFunctionEnd(); + + CurFn = nullptr; +} + +// Usable locations are valid with non-zero line numbers. A line number of zero +// corresponds to optimized code that doesn't have a distinct source location. +// In this case, we try to use the previous or next source location depending on +// the context. +static bool isUsableDebugLoc(DebugLoc DL) { + return DL && DL.getLine() != 0; +} + +void CodeViewDebug::beginInstruction(const MachineInstr *MI) { + DebugHandlerBase::beginInstruction(MI); + + // Ignore DBG_VALUE and DBG_LABEL locations and function prologue. + if (!Asm || !CurFn || MI->isDebugInstr() || + MI->getFlag(MachineInstr::FrameSetup)) + return; + + // If the first instruction of a new MBB has no location, find the first + // instruction with a location and use that. + DebugLoc DL = MI->getDebugLoc(); + if (!isUsableDebugLoc(DL) && MI->getParent() != PrevInstBB) { + for (const auto &NextMI : *MI->getParent()) { + if (NextMI.isDebugInstr()) + continue; + DL = NextMI.getDebugLoc(); + if (isUsableDebugLoc(DL)) + break; + } + // FIXME: Handle the case where the BB has no valid locations. This would + // probably require doing a real dataflow analysis. + } + PrevInstBB = MI->getParent(); + + // If we still don't have a debug location, don't record a location. + if (!isUsableDebugLoc(DL)) + return; + + maybeRecordLocation(DL, Asm->MF); +} + +MCSymbol *CodeViewDebug::beginCVSubsection(DebugSubsectionKind Kind) { + MCSymbol *BeginLabel = MMI->getContext().createTempSymbol(), + *EndLabel = MMI->getContext().createTempSymbol(); + OS.emitInt32(unsigned(Kind)); + OS.AddComment("Subsection size"); + OS.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 4); + OS.emitLabel(BeginLabel); + return EndLabel; +} + +void CodeViewDebug::endCVSubsection(MCSymbol *EndLabel) { + OS.emitLabel(EndLabel); + // Every subsection must be aligned to a 4-byte boundary. + OS.emitValueToAlignment(Align(4)); +} + +static StringRef getSymbolName(SymbolKind SymKind) { + for (const EnumEntry<SymbolKind> &EE : getSymbolTypeNames()) + if (EE.Value == SymKind) + return EE.Name; + return ""; +} + +MCSymbol *CodeViewDebug::beginSymbolRecord(SymbolKind SymKind) { + MCSymbol *BeginLabel = MMI->getContext().createTempSymbol(), + *EndLabel = MMI->getContext().createTempSymbol(); + OS.AddComment("Record length"); + OS.emitAbsoluteSymbolDiff(EndLabel, BeginLabel, 2); + OS.emitLabel(BeginLabel); + if (OS.isVerboseAsm()) + OS.AddComment("Record kind: " + getSymbolName(SymKind)); + OS.emitInt16(unsigned(SymKind)); + return EndLabel; +} + +void CodeViewDebug::endSymbolRecord(MCSymbol *SymEnd) { + // MSVC does not pad out symbol records to four bytes, but LLVM does to avoid + // an extra copy of every symbol record in LLD. This increases object file + // size by less than 1% in the clang build, and is compatible with the Visual + // C++ linker. + OS.emitValueToAlignment(Align(4)); + OS.emitLabel(SymEnd); +} + +void CodeViewDebug::emitEndSymbolRecord(SymbolKind EndKind) { + OS.AddComment("Record length"); + OS.emitInt16(2); + if (OS.isVerboseAsm()) + OS.AddComment("Record kind: " + getSymbolName(EndKind)); + OS.emitInt16(uint16_t(EndKind)); // Record Kind +} + +void CodeViewDebug::emitDebugInfoForUDTs( + const std::vector<std::pair<std::string, const DIType *>> &UDTs) { +#ifndef NDEBUG + size_t OriginalSize = UDTs.size(); +#endif + for (const auto &UDT : UDTs) { + const DIType *T = UDT.second; + assert(shouldEmitUdt(T)); + MCSymbol *UDTRecordEnd = beginSymbolRecord(SymbolKind::S_UDT); + OS.AddComment("Type"); + OS.emitInt32(getCompleteTypeIndex(T).getIndex()); + assert(OriginalSize == UDTs.size() && + "getCompleteTypeIndex found new UDTs!"); + emitNullTerminatedSymbolName(OS, UDT.first); + endSymbolRecord(UDTRecordEnd); + } +} + +void CodeViewDebug::collectGlobalVariableInfo() { + DenseMap<const DIGlobalVariableExpression *, const GlobalVariable *> + GlobalMap; + for (const GlobalVariable &GV : MMI->getModule()->globals()) { + SmallVector<DIGlobalVariableExpression *, 1> GVEs; + GV.getDebugInfo(GVEs); + for (const auto *GVE : GVEs) + GlobalMap[GVE] = &GV; + } + + NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu"); + for (const MDNode *Node : CUs->operands()) { + const auto *CU = cast<DICompileUnit>(Node); + for (const auto *GVE : CU->getGlobalVariables()) { + const DIGlobalVariable *DIGV = GVE->getVariable(); + const DIExpression *DIE = GVE->getExpression(); + // Don't emit string literals in CodeView, as the only useful parts are + // generally the filename and line number, which isn't possible to output + // in CodeView. String literals should be the only unnamed GlobalVariable + // with debug info. + if (DIGV->getName().empty()) continue; + + if ((DIE->getNumElements() == 2) && + (DIE->getElement(0) == dwarf::DW_OP_plus_uconst)) + // Record the constant offset for the variable. + // + // A Fortran common block uses this idiom to encode the offset + // of a variable from the common block's starting address. + CVGlobalVariableOffsets.insert( + std::make_pair(DIGV, DIE->getElement(1))); + + // Emit constant global variables in a global symbol section. + if (GlobalMap.count(GVE) == 0 && DIE->isConstant()) { + CVGlobalVariable CVGV = {DIGV, DIE}; + GlobalVariables.emplace_back(std::move(CVGV)); + } + + const auto *GV = GlobalMap.lookup(GVE); + if (!GV || GV->isDeclarationForLinker()) + continue; + + DIScope *Scope = DIGV->getScope(); + SmallVector<CVGlobalVariable, 1> *VariableList; + if (Scope && isa<DILocalScope>(Scope)) { + // Locate a global variable list for this scope, creating one if + // necessary. + auto Insertion = ScopeGlobals.insert( + {Scope, std::unique_ptr<GlobalVariableList>()}); + if (Insertion.second) + Insertion.first->second = std::make_unique<GlobalVariableList>(); + VariableList = Insertion.first->second.get(); + } else if (GV->hasComdat()) + // Emit this global variable into a COMDAT section. + VariableList = &ComdatVariables; + else + // Emit this global variable in a single global symbol section. + VariableList = &GlobalVariables; + CVGlobalVariable CVGV = {DIGV, GV}; + VariableList->emplace_back(std::move(CVGV)); + } + } +} + +void CodeViewDebug::collectDebugInfoForGlobals() { + for (const CVGlobalVariable &CVGV : GlobalVariables) { + const DIGlobalVariable *DIGV = CVGV.DIGV; + const DIScope *Scope = DIGV->getScope(); + getCompleteTypeIndex(DIGV->getType()); + getFullyQualifiedName(Scope, DIGV->getName()); + } + + for (const CVGlobalVariable &CVGV : ComdatVariables) { + const DIGlobalVariable *DIGV = CVGV.DIGV; + const DIScope *Scope = DIGV->getScope(); + getCompleteTypeIndex(DIGV->getType()); + getFullyQualifiedName(Scope, DIGV->getName()); + } +} + +void CodeViewDebug::emitDebugInfoForGlobals() { + // First, emit all globals that are not in a comdat in a single symbol + // substream. MSVC doesn't like it if the substream is empty, so only open + // it if we have at least one global to emit. + switchToDebugSectionForSymbol(nullptr); + if (!GlobalVariables.empty() || !StaticConstMembers.empty()) { + OS.AddComment("Symbol subsection for globals"); + MCSymbol *EndLabel = beginCVSubsection(DebugSubsectionKind::Symbols); + emitGlobalVariableList(GlobalVariables); + emitStaticConstMemberList(); + endCVSubsection(EndLabel); + } + + // Second, emit each global that is in a comdat into its own .debug$S + // section along with its own symbol substream. + for (const CVGlobalVariable &CVGV : ComdatVariables) { + const GlobalVariable *GV = cast<const GlobalVariable *>(CVGV.GVInfo); + MCSymbol *GVSym = Asm->getSymbol(GV); + OS.AddComment("Symbol subsection for " + + Twine(GlobalValue::dropLLVMManglingEscape(GV->getName()))); + switchToDebugSectionForSymbol(GVSym); + MCSymbol *EndLabel = beginCVSubsection(DebugSubsectionKind::Symbols); + // FIXME: emitDebugInfoForGlobal() doesn't handle DIExpressions. + emitDebugInfoForGlobal(CVGV); + endCVSubsection(EndLabel); + } +} + +void CodeViewDebug::emitDebugInfoForRetainedTypes() { + NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu"); + for (const MDNode *Node : CUs->operands()) { + for (auto *Ty : cast<DICompileUnit>(Node)->getRetainedTypes()) { + if (DIType *RT = dyn_cast<DIType>(Ty)) { + getTypeIndex(RT); + // FIXME: Add to global/local DTU list. + } + } + } +} + +// Emit each global variable in the specified array. +void CodeViewDebug::emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals) { + for (const CVGlobalVariable &CVGV : Globals) { + // FIXME: emitDebugInfoForGlobal() doesn't handle DIExpressions. + emitDebugInfoForGlobal(CVGV); + } +} + +void CodeViewDebug::emitConstantSymbolRecord(const DIType *DTy, APSInt &Value, + const std::string &QualifiedName) { + MCSymbol *SConstantEnd = beginSymbolRecord(SymbolKind::S_CONSTANT); + OS.AddComment("Type"); + OS.emitInt32(getTypeIndex(DTy).getIndex()); + + OS.AddComment("Value"); + + // Encoded integers shouldn't need more than 10 bytes. + uint8_t Data[10]; + BinaryStreamWriter Writer(Data, llvm::support::endianness::little); + CodeViewRecordIO IO(Writer); + cantFail(IO.mapEncodedInteger(Value)); + StringRef SRef((char *)Data, Writer.getOffset()); + OS.emitBinaryData(SRef); + + OS.AddComment("Name"); + emitNullTerminatedSymbolName(OS, QualifiedName); + endSymbolRecord(SConstantEnd); +} + +void CodeViewDebug::emitStaticConstMemberList() { + for (const DIDerivedType *DTy : StaticConstMembers) { + const DIScope *Scope = DTy->getScope(); + + APSInt Value; + if (const ConstantInt *CI = + dyn_cast_or_null<ConstantInt>(DTy->getConstant())) + Value = APSInt(CI->getValue(), + DebugHandlerBase::isUnsignedDIType(DTy->getBaseType())); + else if (const ConstantFP *CFP = + dyn_cast_or_null<ConstantFP>(DTy->getConstant())) + Value = APSInt(CFP->getValueAPF().bitcastToAPInt(), true); + else + llvm_unreachable("cannot emit a constant without a value"); + + emitConstantSymbolRecord(DTy->getBaseType(), Value, + getFullyQualifiedName(Scope, DTy->getName())); + } +} + +static bool isFloatDIType(const DIType *Ty) { + if (isa<DICompositeType>(Ty)) + return false; + + if (auto *DTy = dyn_cast<DIDerivedType>(Ty)) { + dwarf::Tag T = (dwarf::Tag)Ty->getTag(); + if (T == dwarf::DW_TAG_pointer_type || + T == dwarf::DW_TAG_ptr_to_member_type || + T == dwarf::DW_TAG_reference_type || + T == dwarf::DW_TAG_rvalue_reference_type) + return false; + assert(DTy->getBaseType() && "Expected valid base type"); + return isFloatDIType(DTy->getBaseType()); + } + + auto *BTy = cast<DIBasicType>(Ty); + return (BTy->getEncoding() == dwarf::DW_ATE_float); +} + +void CodeViewDebug::emitDebugInfoForGlobal(const CVGlobalVariable &CVGV) { + const DIGlobalVariable *DIGV = CVGV.DIGV; + + const DIScope *Scope = DIGV->getScope(); + // For static data members, get the scope from the declaration. + if (const auto *MemberDecl = dyn_cast_or_null<DIDerivedType>( + DIGV->getRawStaticDataMemberDeclaration())) + Scope = MemberDecl->getScope(); + // For static local variables and Fortran, the scoping portion is elided + // in its name so that we can reference the variable in the command line + // of the VS debugger. + std::string QualifiedName = + (moduleIsInFortran() || (Scope && isa<DILocalScope>(Scope))) + ? std::string(DIGV->getName()) + : getFullyQualifiedName(Scope, DIGV->getName()); + + if (const GlobalVariable *GV = + dyn_cast_if_present<const GlobalVariable *>(CVGV.GVInfo)) { + // DataSym record, see SymbolRecord.h for more info. Thread local data + // happens to have the same format as global data. + MCSymbol *GVSym = Asm->getSymbol(GV); + SymbolKind DataSym = GV->isThreadLocal() + ? (DIGV->isLocalToUnit() ? SymbolKind::S_LTHREAD32 + : SymbolKind::S_GTHREAD32) + : (DIGV->isLocalToUnit() ? SymbolKind::S_LDATA32 + : SymbolKind::S_GDATA32); + MCSymbol *DataEnd = beginSymbolRecord(DataSym); + OS.AddComment("Type"); + OS.emitInt32(getCompleteTypeIndex(DIGV->getType()).getIndex()); + OS.AddComment("DataOffset"); + + uint64_t Offset = 0; + if (CVGlobalVariableOffsets.contains(DIGV)) + // Use the offset seen while collecting info on globals. + Offset = CVGlobalVariableOffsets[DIGV]; + OS.emitCOFFSecRel32(GVSym, Offset); + + OS.AddComment("Segment"); + OS.emitCOFFSectionIndex(GVSym); + OS.AddComment("Name"); + const unsigned LengthOfDataRecord = 12; + emitNullTerminatedSymbolName(OS, QualifiedName, LengthOfDataRecord); + endSymbolRecord(DataEnd); + } else { + const DIExpression *DIE = cast<const DIExpression *>(CVGV.GVInfo); + assert(DIE->isConstant() && + "Global constant variables must contain a constant expression."); + + // Use unsigned for floats. + bool isUnsigned = isFloatDIType(DIGV->getType()) + ? true + : DebugHandlerBase::isUnsignedDIType(DIGV->getType()); + APSInt Value(APInt(/*BitWidth=*/64, DIE->getElement(1)), isUnsigned); + emitConstantSymbolRecord(DIGV->getType(), Value, QualifiedName); + } +} |