diff options
Diffstat (limited to 'lib/CodeGen/AsmPrinter/CodeViewDebug.cpp')
| -rw-r--r-- | lib/CodeGen/AsmPrinter/CodeViewDebug.cpp | 2076 |
1 files changed, 2076 insertions, 0 deletions
diff --git a/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp new file mode 100644 index 000000000000..b0ba57122206 --- /dev/null +++ b/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp @@ -0,0 +1,2076 @@ +//===-- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp --*- C++ -*--===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file contains support for writing Microsoft CodeView debug info. +// +//===----------------------------------------------------------------------===// + +#include "CodeViewDebug.h" +#include "llvm/ADT/TinyPtrVector.h" +#include "llvm/DebugInfo/CodeView/ByteStream.h" +#include "llvm/DebugInfo/CodeView/CVTypeVisitor.h" +#include "llvm/DebugInfo/CodeView/CodeView.h" +#include "llvm/DebugInfo/CodeView/FieldListRecordBuilder.h" +#include "llvm/DebugInfo/CodeView/Line.h" +#include "llvm/DebugInfo/CodeView/SymbolRecord.h" +#include "llvm/DebugInfo/CodeView/TypeDumper.h" +#include "llvm/DebugInfo/CodeView/TypeIndex.h" +#include "llvm/DebugInfo/CodeView/TypeRecord.h" +#include "llvm/DebugInfo/CodeView/TypeVisitorCallbacks.h" +#include "llvm/IR/Constants.h" +#include "llvm/MC/MCExpr.h" +#include "llvm/MC/MCSectionCOFF.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/Support/COFF.h" +#include "llvm/Support/ScopedPrinter.h" +#include "llvm/Target/TargetFrameLowering.h" +#include "llvm/Target/TargetRegisterInfo.h" +#include "llvm/Target/TargetSubtargetInfo.h" + +using namespace llvm; +using namespace llvm::codeview; + +CodeViewDebug::CodeViewDebug(AsmPrinter *AP) + : DebugHandlerBase(AP), OS(*Asm->OutStreamer), CurFn(nullptr) { + // If module doesn't have named metadata anchors or COFF debug section + // is not available, skip any debug info related stuff. + if (!MMI->getModule()->getNamedMetadata("llvm.dbg.cu") || + !AP->getObjFileLowering().getCOFFDebugSymbolsSection()) { + Asm = nullptr; + return; + } + + // Tell MMI that we have debug info. + MMI->setDebugInfoAvailability(true); +} + +StringRef CodeViewDebug::getFullFilepath(const DIFile *File) { + std::string &Filepath = FileToFilepathMap[File]; + if (!Filepath.empty()) + return Filepath; + + StringRef Dir = File->getDirectory(), Filename = File->getFilename(); + + // 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 = 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) { + unsigned NextId = FileIdMap.size() + 1; + auto Insertion = FileIdMap.insert(std::make_pair(F, NextId)); + if (Insertion.second) { + // We have to compute the full filepath and emit a .cv_file directive. + StringRef FullPath = getFullFilepath(F); + NextId = OS.EmitCVFileDirective(NextId, FullPath); + assert(NextId == FileIdMap.size() && ".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) { + Site->SiteFuncId = NextFuncId++; + 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'"; + } + + return StringRef(); +} + +static const DISubprogram *getQualifiedNameComponents( + const DIScope *Scope, SmallVectorImpl<StringRef> &QualifiedNameComponents) { + const DISubprogram *ClosestSubprogram = nullptr; + while (Scope != nullptr) { + if (ClosestSubprogram == nullptr) + ClosestSubprogram = dyn_cast<DISubprogram>(Scope); + StringRef ScopeName = getPrettyScopeName(Scope); + if (!ScopeName.empty()) + QualifiedNameComponents.push_back(ScopeName); + Scope = Scope->getScope().resolve(); + } + return ClosestSubprogram; +} + +static std::string getQualifiedName(ArrayRef<StringRef> QualifiedNameComponents, + StringRef TypeName) { + std::string FullyQualifiedName; + for (StringRef QualifiedNameComponent : reverse(QualifiedNameComponents)) { + FullyQualifiedName.append(QualifiedNameComponent); + FullyQualifiedName.append("::"); + } + FullyQualifiedName.append(TypeName); + return FullyQualifiedName; +} + +static std::string getFullyQualifiedName(const DIScope *Scope, StringRef Name) { + SmallVector<StringRef, 5> QualifiedNameComponents; + getQualifiedNameComponents(Scope, QualifiedNameComponents); + return getQualifiedName(QualifiedNameComponents, Name); +} + +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; +}; + +static std::string getFullyQualifiedName(const DIScope *Ty) { + const DIScope *Scope = Ty->getScope().resolve(); + return getFullyQualifiedName(Scope, getPrettyScopeName(Ty)); +} + +TypeIndex CodeViewDebug::getScopeIndex(const DIScope *Scope) { + // No scope means global scope and that uses the zero index. + if (!Scope || isa<DIFile>(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); + TypeIndex TI = + TypeTable.writeStringId(StringIdRecord(TypeIndex(), ScopeName)); + return recordTypeIndexForDINode(Scope, TI); +} + +TypeIndex CodeViewDebug::getFuncIdForSubprogram(const DISubprogram *SP) { + // It's possible to ask for the FuncId of a function which doesn't have a + // subprogram: inlining a function with debug info into a function with none. + if (!SP) + return TypeIndex::None(); + + // 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. + StringRef DisplayName = SP->getDisplayName().split('<').first; + + const DIScope *Scope = SP->getScope().resolve(); + 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.writeMemberFuncId(MFuncId); + } else { + // Otherwise, this must be a free function. + TypeIndex ParentScope = getScopeIndex(Scope); + FuncIdRecord FuncId(ParentScope, getTypeIndex(SP->getType()), DisplayName); + TI = TypeTable.writeFuncId(FuncId); + } + + return recordTypeIndexForDINode(SP, TI); +} + +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); + TypeIndex TI = + lowerTypeMemberFunction(SP->getType(), Class, SP->getThisAdjustment()); + 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 DILocation *InlinedAt) { + if (InlinedAt) { + // 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(Var); + } else { + // This variable goes in the main ProcSym. + CurFn->Locals.emplace_back(Var); + } +} + +static void addLocIfNotPresent(SmallVectorImpl<const DILocation *> &Locs, + const DILocation *Loc) { + auto B = Locs.begin(), E = Locs.end(); + if (std::find(B, E, Loc) == E) + 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 == CurFn->LastLoc) + return; + + const DIScope *Scope = DL.get()->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 (CurFn->LastLoc.get() && CurFn->LastLoc->getFile() == DL->getFile()) + FileId = CurFn->LastFileId; + else + FileId = CurFn->LastFileId = maybeRecordFile(DL->getFile()); + CurFn->LastLoc = 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()); +} + +void CodeViewDebug::emitCodeViewMagicVersion() { + OS.EmitValueToAlignment(4); + OS.AddComment("Debug section magic"); + OS.EmitIntValue(COFF::DEBUG_SECTION_MAGIC, 4); +} + +void CodeViewDebug::endModule() { + if (!Asm || !MMI->hasDebugInfo()) + return; + + assert(Asm != nullptr); + + // 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); + emitInlineeLinesSubsection(); + + // Emit per-function debug information. + for (auto &P : FnDebugInfo) + if (!P.first->isDeclarationForLinker()) + emitDebugInfoForFunction(P.first, P.second); + + // Emit global variable debug information. + setCurrentSubprogram(nullptr); + emitDebugInfoForGlobals(); + + // Emit retained types. + emitDebugInfoForRetainedTypes(); + + // Switch back to the generic .debug$S section after potentially processing + // comdat symbol sections. + switchToDebugSectionForSymbol(nullptr); + + // Emit UDT records for any types used by global variables. + if (!GlobalUDTs.empty()) { + MCSymbol *SymbolsEnd = beginCVSubsection(ModuleSubstreamKind::Symbols); + emitDebugInfoForUDTs(GlobalUDTs); + endCVSubsection(SymbolsEnd); + } + + // This subsection holds a file index to offset in string table table. + OS.AddComment("File index to string table offset subsection"); + OS.EmitCVFileChecksumsDirective(); + + // This subsection holds the string table. + OS.AddComment("String table"); + OS.EmitCVStringTableDirective(); + + // Emit type information last, so that any types we translate while emitting + // function info are included. + emitTypeInformation(); + + clear(); +} + +static void emitNullTerminatedSymbolName(MCStreamer &OS, StringRef S) { + // Microsoft's linker seems to have trouble with symbol names longer than + // 0xffd8 bytes. + S = S.substr(0, 0xffd8); + SmallString<32> NullTerminatedString(S); + NullTerminatedString.push_back('\0'); + OS.EmitBytes(NullTerminatedString); +} + +void CodeViewDebug::emitTypeInformation() { + // Do nothing if we have no debug info or if no non-trivial types were emitted + // to TypeTable during codegen. + NamedMDNode *CU_Nodes = MMI->getModule()->getNamedMetadata("llvm.dbg.cu"); + if (!CU_Nodes) + return; + if (TypeTable.empty()) + return; + + // Start the .debug$T section with 0x4. + OS.SwitchSection(Asm->getObjFileLowering().getCOFFDebugTypesSection()); + emitCodeViewMagicVersion(); + + SmallString<8> CommentPrefix; + if (OS.isVerboseAsm()) { + CommentPrefix += '\t'; + CommentPrefix += Asm->MAI->getCommentString(); + CommentPrefix += ' '; + } + + CVTypeDumper CVTD(nullptr, /*PrintRecordBytes=*/false); + TypeTable.ForEachRecord( + [&](TypeIndex Index, StringRef Record) { + if (OS.isVerboseAsm()) { + // Emit a block comment describing the type record for readability. + SmallString<512> CommentBlock; + raw_svector_ostream CommentOS(CommentBlock); + ScopedPrinter SP(CommentOS); + SP.setPrefix(CommentPrefix); + CVTD.setPrinter(&SP); + Error E = CVTD.dump({Record.bytes_begin(), Record.bytes_end()}); + if (E) { + logAllUnhandledErrors(std::move(E), errs(), "error: "); + llvm_unreachable("produced malformed type record"); + } + // emitRawComment will insert its own tab and comment string before + // the first line, so strip off our first one. It also prints its own + // newline. + OS.emitRawComment( + CommentOS.str().drop_front(CommentPrefix.size() - 1).rtrim()); + } else { +#ifndef NDEBUG + // Assert that the type data is valid even if we aren't dumping + // comments. The MSVC linker doesn't do much type record validation, + // so the first link of an invalid type record can succeed while + // subsequent links will fail with LNK1285. + ByteStream<> Stream({Record.bytes_begin(), Record.bytes_end()}); + CVTypeArray Types; + StreamReader Reader(Stream); + Error E = Reader.readArray(Types, Reader.getLength()); + if (!E) { + TypeVisitorCallbacks C; + E = CVTypeVisitor(C).visitTypeStream(Types); + } + if (E) { + logAllUnhandledErrors(std::move(E), errs(), "error: "); + llvm_unreachable("produced malformed type record"); + } +#endif + } + OS.EmitBinaryData(Record); + }); +} + +void CodeViewDebug::emitInlineeLinesSubsection() { + if (InlinedSubprograms.empty()) + return; + + OS.AddComment("Inlinee lines subsection"); + MCSymbol *InlineEnd = beginCVSubsection(ModuleSubstreamKind::InlineeLines); + + // We don't provide any extra file info. + // FIXME: Find out if debuggers use this info. + OS.AddComment("Inlinee lines signature"); + OS.EmitIntValue(unsigned(InlineeLinesSignature::Normal), 4); + + 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->getDisplayName() + " starts at " + + SP->getFilename() + Twine(':') + Twine(SP->getLine())); + OS.AddBlankLine(); + // The filechecksum table uses 8 byte entries for now, and file ids start at + // 1. + unsigned FileOffset = (FileId - 1) * 8; + OS.AddComment("Type index of inlined function"); + OS.EmitIntValue(InlineeIdx.getIndex(), 4); + OS.AddComment("Offset into filechecksum table"); + OS.EmitIntValue(FileOffset, 4); + OS.AddComment("Starting line number"); + OS.EmitIntValue(SP->getLine(), 4); + } + + endCVSubsection(InlineEnd); +} + +void CodeViewDebug::collectInlineSiteChildren( + SmallVectorImpl<unsigned> &Children, const FunctionInfo &FI, + const InlineSite &Site) { + for (const DILocation *ChildSiteLoc : Site.ChildSites) { + auto I = FI.InlineSites.find(ChildSiteLoc); + const InlineSite &ChildSite = I->second; + Children.push_back(ChildSite.SiteFuncId); + collectInlineSiteChildren(Children, FI, ChildSite); + } +} + +void CodeViewDebug::emitInlinedCallSite(const FunctionInfo &FI, + const DILocation *InlinedAt, + const InlineSite &Site) { + MCSymbol *InlineBegin = MMI->getContext().createTempSymbol(), + *InlineEnd = MMI->getContext().createTempSymbol(); + + assert(TypeIndices.count({Site.Inlinee, nullptr})); + TypeIndex InlineeIdx = TypeIndices[{Site.Inlinee, nullptr}]; + + // SymbolRecord + OS.AddComment("Record length"); + OS.emitAbsoluteSymbolDiff(InlineEnd, InlineBegin, 2); // RecordLength + OS.EmitLabel(InlineBegin); + OS.AddComment("Record kind: S_INLINESITE"); + OS.EmitIntValue(SymbolKind::S_INLINESITE, 2); // RecordKind + + OS.AddComment("PtrParent"); + OS.EmitIntValue(0, 4); + OS.AddComment("PtrEnd"); + OS.EmitIntValue(0, 4); + OS.AddComment("Inlinee type index"); + OS.EmitIntValue(InlineeIdx.getIndex(), 4); + + unsigned FileId = maybeRecordFile(Site.Inlinee->getFile()); + unsigned StartLineNum = Site.Inlinee->getLine(); + SmallVector<unsigned, 3> SecondaryFuncIds; + collectInlineSiteChildren(SecondaryFuncIds, FI, Site); + + OS.EmitCVInlineLinetableDirective(Site.SiteFuncId, FileId, StartLineNum, + FI.Begin, FI.End, SecondaryFuncIds); + + OS.EmitLabel(InlineEnd); + + emitLocalVariableList(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. + OS.AddComment("Record length"); + OS.EmitIntValue(2, 2); // RecordLength + OS.AddComment("Record kind: S_INLINESITE_END"); + OS.EmitIntValue(SymbolKind::S_INLINESITE_END, 2); // RecordKind +} + +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(); +} + +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(); + setCurrentSubprogram(SP); + + // If we have a display name, build the fully qualified name by walking the + // chain of scopes. + if (SP != nullptr && !SP->getDisplayName().empty()) + FuncName = + getFullyQualifiedName(SP->getScope().resolve(), SP->getDisplayName()); + + // If our DISubprogram name is empty, use the mangled name. + if (FuncName.empty()) + FuncName = GlobalValue::getRealLinkageName(GV->getName()); + + // Emit a symbol subsection, required by VS2012+ to find function boundaries. + OS.AddComment("Symbol subsection for " + Twine(FuncName)); + MCSymbol *SymbolsEnd = beginCVSubsection(ModuleSubstreamKind::Symbols); + { + MCSymbol *ProcRecordBegin = MMI->getContext().createTempSymbol(), + *ProcRecordEnd = MMI->getContext().createTempSymbol(); + OS.AddComment("Record length"); + OS.emitAbsoluteSymbolDiff(ProcRecordEnd, ProcRecordBegin, 2); + OS.EmitLabel(ProcRecordBegin); + + if (GV->hasLocalLinkage()) { + OS.AddComment("Record kind: S_LPROC32_ID"); + OS.EmitIntValue(unsigned(SymbolKind::S_LPROC32_ID), 2); + } else { + OS.AddComment("Record kind: S_GPROC32_ID"); + OS.EmitIntValue(unsigned(SymbolKind::S_GPROC32_ID), 2); + } + + // These fields are filled in by tools like CVPACK which run after the fact. + OS.AddComment("PtrParent"); + OS.EmitIntValue(0, 4); + OS.AddComment("PtrEnd"); + OS.EmitIntValue(0, 4); + OS.AddComment("PtrNext"); + OS.EmitIntValue(0, 4); + // 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.EmitIntValue(0, 4); + OS.AddComment("Offset before epilogue"); + OS.EmitIntValue(0, 4); + OS.AddComment("Function type index"); + OS.EmitIntValue(getFuncIdForSubprogram(GV->getSubprogram()).getIndex(), 4); + OS.AddComment("Function section relative address"); + OS.EmitCOFFSecRel32(Fn); + OS.AddComment("Function section index"); + OS.EmitCOFFSectionIndex(Fn); + OS.AddComment("Flags"); + OS.EmitIntValue(0, 1); + // 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); + OS.EmitLabel(ProcRecordEnd); + + emitLocalVariableList(FI.Locals); + + // 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); + } + + if (SP != nullptr) + emitDebugInfoForUDTs(LocalUDTs); + + // We're done with this function. + OS.AddComment("Record length"); + OS.EmitIntValue(0x0002, 2); + OS.AddComment("Record kind: S_PROC_ID_END"); + OS.EmitIntValue(unsigned(SymbolKind::S_PROC_ID_END), 2); + } + endCVSubsection(SymbolsEnd); + + // We have an assembler directive that takes care of the whole line table. + OS.EmitCVLinetableDirective(FI.FuncId, Fn, FI.End); +} + +CodeViewDebug::LocalVarDefRange +CodeViewDebug::createDefRangeMem(uint16_t CVRegister, int Offset) { + LocalVarDefRange DR; + DR.InMemory = -1; + DR.DataOffset = Offset; + assert(DR.DataOffset == Offset && "truncation"); + DR.StructOffset = 0; + DR.CVRegister = CVRegister; + return DR; +} + +CodeViewDebug::LocalVarDefRange +CodeViewDebug::createDefRangeReg(uint16_t CVRegister) { + LocalVarDefRange DR; + DR.InMemory = 0; + DR.DataOffset = 0; + DR.StructOffset = 0; + DR.CVRegister = CVRegister; + return DR; +} + +void CodeViewDebug::collectVariableInfoFromMMITable( + DenseSet<InlinedVariable> &Processed) { + const TargetSubtargetInfo &TSI = Asm->MF->getSubtarget(); + const TargetFrameLowering *TFI = TSI.getFrameLowering(); + const TargetRegisterInfo *TRI = TSI.getRegisterInfo(); + + for (const MachineModuleInfo::VariableDbgInfo &VI : + MMI->getVariableDbgInfo()) { + if (!VI.Var) + continue; + assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) && + "Expected inlined-at fields to agree"); + + Processed.insert(InlinedVariable(VI.Var, VI.Loc->getInlinedAt())); + LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc); + + // If variable scope is not found then skip this variable. + if (!Scope) + continue; + + // Get the frame register used and the offset. + unsigned FrameReg = 0; + int FrameOffset = TFI->getFrameIndexReference(*Asm->MF, VI.Slot, FrameReg); + uint16_t CVReg = TRI->getCodeViewRegNum(FrameReg); + + // Calculate the label ranges. + LocalVarDefRange DefRange = createDefRangeMem(CVReg, FrameOffset); + for (const InsnRange &Range : Scope->getRanges()) { + const MCSymbol *Begin = getLabelBeforeInsn(Range.first); + const MCSymbol *End = getLabelAfterInsn(Range.second); + End = End ? End : Asm->getFunctionEnd(); + DefRange.Ranges.emplace_back(Begin, End); + } + + LocalVariable Var; + Var.DIVar = VI.Var; + Var.DefRanges.emplace_back(std::move(DefRange)); + recordLocalVariable(std::move(Var), VI.Loc->getInlinedAt()); + } +} + +void CodeViewDebug::collectVariableInfo(const DISubprogram *SP) { + DenseSet<InlinedVariable> Processed; + // Grab the variable info that was squirreled away in the MMI side-table. + collectVariableInfoFromMMITable(Processed); + + const TargetRegisterInfo *TRI = Asm->MF->getSubtarget().getRegisterInfo(); + + for (const auto &I : DbgValues) { + InlinedVariable IV = I.first; + if (Processed.count(IV)) + continue; + const DILocalVariable *DIVar = IV.first; + const DILocation *InlinedAt = IV.second; + + // Instruction ranges, specifying where IV is accessible. + const auto &Ranges = 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; + + // Calculate the definition ranges. + for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) { + const InsnRange &Range = *I; + const MachineInstr *DVInst = Range.first; + assert(DVInst->isDebugValue() && "Invalid History entry"); + const DIExpression *DIExpr = DVInst->getDebugExpression(); + + // Bail if there is a complex DWARF expression for now. + if (DIExpr && DIExpr->getNumElements() > 0) + continue; + + // Bail if operand 0 is not a valid register. This means the variable is a + // simple constant, or is described by a complex expression. + // FIXME: Find a way to represent constant variables, since they are + // relatively common. + unsigned Reg = + DVInst->getOperand(0).isReg() ? DVInst->getOperand(0).getReg() : 0; + if (Reg == 0) + continue; + + // Handle the two cases we can handle: indirect in memory and in register. + bool IsIndirect = DVInst->getOperand(1).isImm(); + unsigned CVReg = TRI->getCodeViewRegNum(DVInst->getOperand(0).getReg()); + { + LocalVarDefRange DefRange; + if (IsIndirect) { + int64_t Offset = DVInst->getOperand(1).getImm(); + DefRange = createDefRangeMem(CVReg, Offset); + } else { + DefRange = createDefRangeReg(CVReg); + } + if (Var.DefRanges.empty() || + Var.DefRanges.back().isDifferentLocation(DefRange)) { + Var.DefRanges.emplace_back(std::move(DefRange)); + } + } + + // Compute the label range. + const MCSymbol *Begin = getLabelBeforeInsn(Range.first); + const MCSymbol *End = getLabelAfterInsn(Range.second); + if (!End) { + if (std::next(I) != E) + End = getLabelBeforeInsn(std::next(I)->first); + 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 *>> &Ranges = + Var.DefRanges.back().Ranges; + if (!Ranges.empty() && Ranges.back().second == Begin) + Ranges.back().second = End; + else + Ranges.emplace_back(Begin, End); + + // FIXME: Do more range combining. + } + + recordLocalVariable(std::move(Var), InlinedAt); + } +} + +void CodeViewDebug::beginFunction(const MachineFunction *MF) { + assert(!CurFn && "Can't process two functions at once!"); + + if (!Asm || !MMI->hasDebugInfo()) + return; + + DebugHandlerBase::beginFunction(MF); + + const Function *GV = MF->getFunction(); + assert(FnDebugInfo.count(GV) == false); + CurFn = &FnDebugInfo[GV]; + CurFn->FuncId = NextFuncId++; + CurFn->Begin = Asm->getFunctionBegin(); + + // 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.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) && + MI.getDebugLoc()) { + PrologEndLoc = MI.getDebugLoc(); + break; + } else if (!MI.isDebugValue()) { + EmptyPrologue = false; + } + } + } + + // Record beginning of function if we have a non-empty prologue. + if (PrologEndLoc && !EmptyPrologue) { + DebugLoc FnStartDL = PrologEndLoc.getFnDebugLoc(); + maybeRecordLocation(FnStartDL, MF); + } +} + +void CodeViewDebug::addToUDTs(const DIType *Ty, TypeIndex TI) { + // Don't record empty UDTs. + if (Ty->getName().empty()) + return; + + SmallVector<StringRef, 5> QualifiedNameComponents; + const DISubprogram *ClosestSubprogram = getQualifiedNameComponents( + Ty->getScope().resolve(), QualifiedNameComponents); + + std::string FullyQualifiedName = + getQualifiedName(QualifiedNameComponents, getPrettyScopeName(Ty)); + + if (ClosestSubprogram == nullptr) + GlobalUDTs.emplace_back(std::move(FullyQualifiedName), TI); + else if (ClosestSubprogram == CurrentSubprogram) + LocalUDTs.emplace_back(std::move(FullyQualifiedName), TI); + + // 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: + 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_const_type: + case dwarf::DW_TAG_volatile_type: + 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); + } + 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)); + default: + // Use the null type index. + return TypeIndex(); + } +} + +TypeIndex CodeViewDebug::lowerTypeAlias(const DIDerivedType *Ty) { + DITypeRef UnderlyingTypeRef = Ty->getBaseType(); + TypeIndex UnderlyingTypeIndex = getTypeIndex(UnderlyingTypeRef); + StringRef TypeName = Ty->getName(); + + addToUDTs(Ty, UnderlyingTypeIndex); + + 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) { + DITypeRef ElementTypeRef = Ty->getBaseType(); + TypeIndex ElementTypeIndex = getTypeIndex(ElementTypeRef); + // IndexType is size_t, which depends on the bitness of the target. + TypeIndex IndexType = Asm->MAI->getPointerSize() == 8 + ? TypeIndex(SimpleTypeKind::UInt64Quad) + : TypeIndex(SimpleTypeKind::UInt32Long); + + uint64_t ElementSize = getBaseTypeSize(ElementTypeRef) / 8; + + bool UndefinedSubrange = false; + + // FIXME: + // There is a bug in the front-end where an array of a structure, which was + // declared as incomplete structure first, ends up not getting a size assigned + // to it. (PR28303) + // Example: + // struct A(*p)[3]; + // struct A { int f; } a[3]; + // + // This needs to be fixed in the front-end, but in the meantime we don't want + // to trigger an assertion because of this. + if (Ty->getSizeInBits() == 0) { + UndefinedSubrange = true; + } + + // 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); + assert(Subrange->getLowerBound() == 0 && + "codeview doesn't support subranges with lower bounds"); + int64_t Count = Subrange->getCount(); + + // Variable Length Array (VLA) has Count equal to '-1'. + // Replace with Count '1', assume it is the minimum VLA length. + // FIXME: Make front-end support VLA subrange and emit LF_DIMVARLU. + if (Count == -1) { + Count = 1; + UndefinedSubrange = true; + } + + StringRef Name = (i == 0) ? Ty->getName() : ""; + // Update the element size and element type index for subsequent subranges. + ElementSize *= Count; + ElementTypeIndex = TypeTable.writeArray( + ArrayRecord(ElementTypeIndex, IndexType, ElementSize, Name)); + } + + (void)UndefinedSubrange; + assert(UndefinedSubrange || ElementSize == (Ty->getSizeInBits() / 8)); + + return ElementTypeIndex; +} + +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: + switch (ByteSize) { + case 2: STK = SimpleTypeKind::Complex16; break; + case 4: STK = SimpleTypeKind::Complex32; break; + case 8: STK = SimpleTypeKind::Complex64; break; + case 10: STK = SimpleTypeKind::Complex80; break; + case 16: 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::SByte; 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::Byte; 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 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. + if (STK == SimpleTypeKind::Int32 && Ty->getName() == "long int") + STK = SimpleTypeKind::Int32Long; + if (STK == SimpleTypeKind::UInt32 && Ty->getName() == "long unsigned int") + 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) { + TypeIndex PointeeTI = getTypeIndex(Ty->getBaseType()); + + // While processing the type being pointed to it is possible we already + // created this pointer type. If so, we check here and return the existing + // pointer type. + auto I = TypeIndices.find({Ty, nullptr}); + if (I != TypeIndices.end()) + return I->second; + + // Pointers to simple types can use SimpleTypeMode, rather than having a + // dedicated pointer type record. + if (PointeeTI.isSimple() && + 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; + } + // FIXME: MSVC folds qualifiers into PointerOptions in the context of a method + // 'this' pointer, but not normal contexts. Figure out what we're supposed to + // do. + PointerOptions PO = PointerOptions::None; + PointerRecord PR(PointeeTI, PK, PM, PO, Ty->getSizeInBits() / 8); + return TypeTable.writePointer(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) { + assert(Ty->getTag() == dwarf::DW_TAG_ptr_to_member_type); + TypeIndex ClassTI = getTypeIndex(Ty->getClassType()); + TypeIndex PointeeTI = getTypeIndex(Ty->getBaseType(), Ty->getClassType()); + PointerKind PK = Asm->MAI->getPointerSize() == 8 ? PointerKind::Near64 + : PointerKind::Near32; + bool IsPMF = isa<DISubroutineType>(Ty->getBaseType()); + PointerMode PM = IsPMF ? PointerMode::PointerToMemberFunction + : PointerMode::PointerToDataMember; + PointerOptions PO = PointerOptions::None; // FIXME + 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.writePointer(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; + bool IsModifier = true; + const DIType *BaseTy = Ty; + while (IsModifier && BaseTy) { + // FIXME: Need to add DWARF tag for __unaligned. + switch (BaseTy->getTag()) { + case dwarf::DW_TAG_const_type: + Mods |= ModifierOptions::Const; + break; + case dwarf::DW_TAG_volatile_type: + Mods |= ModifierOptions::Volatile; + break; + default: + IsModifier = false; + break; + } + if (IsModifier) + BaseTy = cast<DIDerivedType>(BaseTy)->getBaseType().resolve(); + } + TypeIndex ModifiedTI = getTypeIndex(BaseTy); + + // While processing the type being pointed to, it is possible we already + // created this modifier type. If so, we check here and return the existing + // modifier type. + auto I = TypeIndices.find({Ty, nullptr}); + if (I != TypeIndices.end()) + return I->second; + + ModifierRecord MR(ModifiedTI, Mods); + return TypeTable.writeModifier(MR); +} + +TypeIndex CodeViewDebug::lowerTypeFunction(const DISubroutineType *Ty) { + SmallVector<TypeIndex, 8> ReturnAndArgTypeIndices; + for (DITypeRef ArgTypeRef : Ty->getTypeArray()) + ReturnAndArgTypeIndices.push_back(getTypeIndex(ArgTypeRef)); + + TypeIndex ReturnTypeIndex = TypeIndex::Void(); + ArrayRef<TypeIndex> ArgTypeIndices = None; + if (!ReturnAndArgTypeIndices.empty()) { + auto ReturnAndArgTypesRef = makeArrayRef(ReturnAndArgTypeIndices); + ReturnTypeIndex = ReturnAndArgTypesRef.front(); + ArgTypeIndices = ReturnAndArgTypesRef.drop_front(); + } + + ArgListRecord ArgListRec(TypeRecordKind::ArgList, ArgTypeIndices); + TypeIndex ArgListIndex = TypeTable.writeArgList(ArgListRec); + + CallingConvention CC = dwarfCCToCodeView(Ty->getCC()); + + ProcedureRecord Procedure(ReturnTypeIndex, CC, FunctionOptions::None, + ArgTypeIndices.size(), ArgListIndex); + return TypeTable.writeProcedure(Procedure); +} + +TypeIndex CodeViewDebug::lowerTypeMemberFunction(const DISubroutineType *Ty, + const DIType *ClassTy, + int ThisAdjustment) { + // Lower the containing class type. + TypeIndex ClassType = getTypeIndex(ClassTy); + + SmallVector<TypeIndex, 8> ReturnAndArgTypeIndices; + for (DITypeRef ArgTypeRef : Ty->getTypeArray()) + ReturnAndArgTypeIndices.push_back(getTypeIndex(ArgTypeRef)); + + TypeIndex ReturnTypeIndex = TypeIndex::Void(); + ArrayRef<TypeIndex> ArgTypeIndices = None; + if (!ReturnAndArgTypeIndices.empty()) { + auto ReturnAndArgTypesRef = makeArrayRef(ReturnAndArgTypeIndices); + ReturnTypeIndex = ReturnAndArgTypesRef.front(); + ArgTypeIndices = ReturnAndArgTypesRef.drop_front(); + } + TypeIndex ThisTypeIndex = TypeIndex::Void(); + if (!ArgTypeIndices.empty()) { + ThisTypeIndex = ArgTypeIndices.front(); + ArgTypeIndices = ArgTypeIndices.drop_front(); + } + + ArgListRecord ArgListRec(TypeRecordKind::ArgList, ArgTypeIndices); + TypeIndex ArgListIndex = TypeTable.writeArgList(ArgListRec); + + CallingConvention CC = dwarfCCToCodeView(Ty->getCC()); + + // TODO: Need to use the correct values for: + // FunctionOptions + // ThisPointerAdjustment. + TypeIndex TI = TypeTable.writeMemberFunction(MemberFunctionRecord( + ReturnTypeIndex, ClassType, ThisTypeIndex, CC, FunctionOptions::None, + ArgTypeIndices.size(), ArgListIndex, ThisAdjustment)); + + return TI; +} + +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) { + 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"); + } + + // FIXME: Get Clang to mark DISubprogram as static and do something with it. + + 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; + } + 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().resolve(); + if (ImmediateScope && isa<DICompositeType>(ImmediateScope)) + CO |= ClassOptions::Nested; + + // Put the Scoped flag on function-local types. + for (const DIScope *Scope = ImmediateScope; Scope != nullptr; + Scope = Scope->getScope().resolve()) { + if (isa<DISubprogram>(Scope)) { + CO |= ClassOptions::Scoped; + break; + } + } + + return CO; +} + +TypeIndex CodeViewDebug::lowerTypeEnum(const DICompositeType *Ty) { + ClassOptions CO = getCommonClassOptions(Ty); + TypeIndex FTI; + unsigned EnumeratorCount = 0; + + if (Ty->isForwardDecl()) { + CO |= ClassOptions::ForwardReference; + } else { + FieldListRecordBuilder Fields; + 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)) { + Fields.writeEnumerator(EnumeratorRecord( + MemberAccess::Public, APSInt::getUnsigned(Enumerator->getValue()), + Enumerator->getName())); + EnumeratorCount++; + } + } + FTI = TypeTable.writeFieldList(Fields); + } + + std::string FullName = getFullyQualifiedName(Ty); + + return TypeTable.writeEnum(EnumRecord(EnumeratorCount, CO, FTI, FullName, + Ty->getIdentifier(), + getTypeIndex(Ty->getBaseType()))); +} + +//===----------------------------------------------------------------------===// +// ClassInfo +//===----------------------------------------------------------------------===// + +struct llvm::ClassInfo { + struct MemberInfo { + const DIDerivedType *MemberTypeNode; + uint64_t BaseOffset; + }; + // [MemberInfo] + typedef std::vector<MemberInfo> MemberList; + + typedef TinyPtrVector<const DISubprogram *> MethodsList; + // MethodName -> MethodsList + typedef MapVector<MDString *, MethodsList> MethodsMap; + + /// Base classes. + std::vector<const DIDerivedType *> Inheritance; + + /// Direct members. + MemberList Members; + // Direct overloaded methods gathered by name. + MethodsMap Methods; + + std::vector<const DICompositeType *> NestedClasses; +}; + +void CodeViewDebug::clear() { + assert(CurFn == nullptr); + FileIdMap.clear(); + FnDebugInfo.clear(); + FileToFilepathMap.clear(); + LocalUDTs.clear(); + GlobalUDTs.clear(); + TypeIndices.clear(); + CompleteTypeIndices.clear(); +} + +void CodeViewDebug::collectMemberInfo(ClassInfo &Info, + const DIDerivedType *DDTy) { + if (!DDTy->getName().empty()) { + Info.Members.push_back({DDTy, 0}); + return; + } + // An unnamed member must represent a nested struct or union. Add all the + // indirect fields to the current record. + assert((DDTy->getOffsetInBits() % 8) == 0 && "Unnamed bitfield member!"); + uint64_t Offset = DDTy->getOffsetInBits(); + const DIType *Ty = DDTy->getBaseType().resolve(); + const DICompositeType *DCTy = cast<DICompositeType>(Ty); + 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_friend) { + // Ignore friend members. It appears that MSVC emitted info about + // friends in the past, but modern versions do not. + } + // FIXME: Get Clang to emit function virtual table here and handle it. + } else if (auto *Composite = dyn_cast<DICompositeType>(Element)) { + Info.NestedClasses.push_back(Composite); + } + // Skip other unrecognized kinds of elements. + } + return Info; +} + +TypeIndex CodeViewDebug::lowerTypeClass(const DICompositeType *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); + TypeIndex FwdDeclTI = TypeTable.writeClass(ClassRecord( + Kind, 0, CO, HfaKind::None, WindowsRTClassKind::None, TypeIndex(), + TypeIndex(), TypeIndex(), 0, FullName, Ty->getIdentifier())); + 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; + + std::string FullName = getFullyQualifiedName(Ty); + + uint64_t SizeInBytes = Ty->getSizeInBits() / 8; + + TypeIndex ClassTI = TypeTable.writeClass(ClassRecord( + Kind, FieldCount, CO, HfaKind::None, WindowsRTClassKind::None, FieldTI, + TypeIndex(), VShapeTI, SizeInBytes, FullName, Ty->getIdentifier())); + + TypeTable.writeUdtSourceLine(UdtSourceLineRecord( + ClassTI, TypeTable.writeStringId(StringIdRecord( + TypeIndex(0x0), getFullFilepath(Ty->getFile()))), + Ty->getLine())); + + addToUDTs(Ty, ClassTI); + + return ClassTI; +} + +TypeIndex CodeViewDebug::lowerTypeUnion(const DICompositeType *Ty) { + ClassOptions CO = + ClassOptions::ForwardReference | getCommonClassOptions(Ty); + std::string FullName = getFullyQualifiedName(Ty); + TypeIndex FwdDeclTI = + TypeTable.writeUnion(UnionRecord(0, CO, HfaKind::None, TypeIndex(), 0, + FullName, Ty->getIdentifier())); + 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); + + TypeIndex UnionTI = TypeTable.writeUnion( + UnionRecord(FieldCount, CO, HfaKind::None, FieldTI, SizeInBytes, FullName, + Ty->getIdentifier())); + + TypeTable.writeUdtSourceLine(UdtSourceLineRecord( + UnionTI, TypeTable.writeStringId(StringIdRecord( + TypeIndex(0x0), getFullFilepath(Ty->getFile()))), + Ty->getLine())); + + addToUDTs(Ty, UnionTI); + + 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); + FieldListRecordBuilder Fields; + + // Create base classes. + for (const DIDerivedType *I : Info.Inheritance) { + if (I->getFlags() & DINode::FlagVirtual) { + // Virtual base. + // FIXME: Emit VBPtrOffset when the frontend provides it. + unsigned VBPtrOffset = 0; + // FIXME: Despite the accessor name, the offset is really in bytes. + unsigned VBTableIndex = I->getOffsetInBits() / 4; + Fields.writeVirtualBaseClass(VirtualBaseClassRecord( + translateAccessFlags(Ty->getTag(), I->getFlags()), + getTypeIndex(I->getBaseType()), getVBPTypeIndex(), VBPtrOffset, + VBTableIndex)); + } else { + assert(I->getOffsetInBits() % 8 == 0 && + "bases must be on byte boundaries"); + Fields.writeBaseClass(BaseClassRecord( + translateAccessFlags(Ty->getTag(), I->getFlags()), + getTypeIndex(I->getBaseType()), I->getOffsetInBits() / 8)); + } + } + + // 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()) { + Fields.writeStaticDataMember( + StaticDataMemberRecord(Access, MemberBaseType, MemberName)); + 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; + MemberBaseType = TypeTable.writeBitField(BitFieldRecord( + MemberBaseType, Member->getSizeInBits(), StartBitOffset)); + } + uint64_t MemberOffsetInBytes = MemberOffsetInBits / 8; + Fields.writeDataMember(DataMemberRecord(Access, MemberBaseType, + MemberOffsetInBytes, MemberName)); + 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, translateMethodKindFlags(SP, Introduced), + translateMethodOptionFlags(SP), + translateAccessFlags(Ty->getTag(), SP->getFlags()), + VFTableOffset, Name)); + MemberCount++; + } + assert(Methods.size() > 0 && "Empty methods map entry"); + if (Methods.size() == 1) + Fields.writeOneMethod(Methods[0]); + else { + TypeIndex MethodList = + TypeTable.writeMethodOverloadList(MethodOverloadListRecord(Methods)); + Fields.writeOverloadedMethod( + OverloadedMethodRecord(Methods.size(), MethodList, Name)); + } + } + + // Create nested classes. + for (const DICompositeType *Nested : Info.NestedClasses) { + NestedTypeRecord R(getTypeIndex(DITypeRef(Nested)), Nested->getName()); + Fields.writeNestedType(R); + MemberCount++; + } + + TypeIndex FieldTI = TypeTable.writeFieldList(Fields); + return std::make_tuple(FieldTI, TypeIndex(), MemberCount, + !Info.NestedClasses.empty()); +} + +TypeIndex CodeViewDebug::getVBPTypeIndex() { + if (!VBPType.getIndex()) { + // Make a 'const int *' type. + ModifierRecord MR(TypeIndex::Int32(), ModifierOptions::Const); + TypeIndex ModifiedTI = TypeTable.writeModifier(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.writePointer(PR); + } + + return VBPType; +} + +TypeIndex CodeViewDebug::getTypeIndex(DITypeRef TypeRef, DITypeRef ClassTyRef) { + const DIType *Ty = TypeRef.resolve(); + const DIType *ClassTy = ClassTyRef.resolve(); + + // 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); +} + +TypeIndex CodeViewDebug::getCompleteTypeIndex(DITypeRef TypeRef) { + const DIType *Ty = TypeRef.resolve(); + + // The null DIType is the void type. Don't try to hash it. + if (!Ty) + return TypeIndex::Void(); + + // 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); + } + + // Check if we've already translated the complete record type. Lowering a + // complete type should never trigger lowering another complete type, so we + // can reuse the hash table lookup result. + const auto *CTy = cast<DICompositeType>(Ty); + auto InsertResult = CompleteTypeIndices.insert({CTy, TypeIndex()}); + if (!InsertResult.second) + return InsertResult.first->second; + + 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. + 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; + + 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"); + } + + InsertResult.first->second = 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(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); + std::sort(Params.begin(), Params.end(), + [](const LocalVariable *L, const LocalVariable *R) { + return L->DIVar->getArg() < R->DIVar->getArg(); + }); + for (const LocalVariable *L : Params) + emitLocalVariable(*L); + + // Next emit all non-parameters in the order that we found them. + for (const LocalVariable &L : Locals) + if (!L.DIVar->isParameter()) + emitLocalVariable(L); +} + +void CodeViewDebug::emitLocalVariable(const LocalVariable &Var) { + // LocalSym record, see SymbolRecord.h for more info. + MCSymbol *LocalBegin = MMI->getContext().createTempSymbol(), + *LocalEnd = MMI->getContext().createTempSymbol(); + OS.AddComment("Record length"); + OS.emitAbsoluteSymbolDiff(LocalEnd, LocalBegin, 2); + OS.EmitLabel(LocalBegin); + + OS.AddComment("Record kind: S_LOCAL"); + OS.EmitIntValue(unsigned(SymbolKind::S_LOCAL), 2); + + LocalSymFlags Flags = LocalSymFlags::None; + if (Var.DIVar->isParameter()) + Flags |= LocalSymFlags::IsParameter; + if (Var.DefRanges.empty()) + Flags |= LocalSymFlags::IsOptimizedOut; + + OS.AddComment("TypeIndex"); + TypeIndex TI = getCompleteTypeIndex(Var.DIVar->getType()); + OS.EmitIntValue(TI.getIndex(), 4); + OS.AddComment("Flags"); + OS.EmitIntValue(static_cast<uint16_t>(Flags), 2); + // Truncate the name so we won't overflow the record length field. + emitNullTerminatedSymbolName(OS, Var.DIVar->getName()); + OS.EmitLabel(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 LocalVarDefRange &DefRange : Var.DefRanges) { + BytePrefix.clear(); + // FIXME: Handle bitpieces. + if (DefRange.StructOffset != 0) + continue; + + if (DefRange.InMemory) { + DefRangeRegisterRelSym Sym(DefRange.CVRegister, 0, DefRange.DataOffset, 0, + 0, 0, ArrayRef<LocalVariableAddrGap>()); + ulittle16_t SymKind = ulittle16_t(S_DEFRANGE_REGISTER_REL); + BytePrefix += + StringRef(reinterpret_cast<const char *>(&SymKind), sizeof(SymKind)); + BytePrefix += + StringRef(reinterpret_cast<const char *>(&Sym.Header), + sizeof(Sym.Header) - sizeof(LocalVariableAddrRange)); + } else { + assert(DefRange.DataOffset == 0 && "unexpected offset into register"); + // Unclear what matters here. + DefRangeRegisterSym Sym(DefRange.CVRegister, 0, 0, 0, 0, + ArrayRef<LocalVariableAddrGap>()); + ulittle16_t SymKind = ulittle16_t(S_DEFRANGE_REGISTER); + BytePrefix += + StringRef(reinterpret_cast<const char *>(&SymKind), sizeof(SymKind)); + BytePrefix += + StringRef(reinterpret_cast<const char *>(&Sym.Header), + sizeof(Sym.Header) - sizeof(LocalVariableAddrRange)); + } + OS.EmitCVDefRangeDirective(DefRange.Ranges, BytePrefix); + } +} + +void CodeViewDebug::endFunction(const MachineFunction *MF) { + if (!Asm || !CurFn) // We haven't created any debug info for this function. + return; + + const Function *GV = MF->getFunction(); + assert(FnDebugInfo.count(GV)); + assert(CurFn == &FnDebugInfo[GV]); + + collectVariableInfo(GV->getSubprogram()); + + DebugHandlerBase::endFunction(MF); + + // Don't emit anything if we don't have any line tables. + if (!CurFn->HaveLineInfo) { + FnDebugInfo.erase(GV); + CurFn = nullptr; + return; + } + + CurFn->End = Asm->getFunctionEnd(); + + CurFn = nullptr; +} + +void CodeViewDebug::beginInstruction(const MachineInstr *MI) { + DebugHandlerBase::beginInstruction(MI); + + // Ignore DBG_VALUE locations and function prologue. + if (!Asm || MI->isDebugValue() || MI->getFlag(MachineInstr::FrameSetup)) + return; + DebugLoc DL = MI->getDebugLoc(); + if (DL == PrevInstLoc || !DL) + return; + maybeRecordLocation(DL, Asm->MF); +} + +MCSymbol *CodeViewDebug::beginCVSubsection(ModuleSubstreamKind Kind) { + MCSymbol *BeginLabel = MMI->getContext().createTempSymbol(), + *EndLabel = MMI->getContext().createTempSymbol(); + OS.EmitIntValue(unsigned(Kind), 4); + 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(4); +} + +void CodeViewDebug::emitDebugInfoForUDTs( + ArrayRef<std::pair<std::string, TypeIndex>> UDTs) { + for (const std::pair<std::string, codeview::TypeIndex> &UDT : UDTs) { + MCSymbol *UDTRecordBegin = MMI->getContext().createTempSymbol(), + *UDTRecordEnd = MMI->getContext().createTempSymbol(); + OS.AddComment("Record length"); + OS.emitAbsoluteSymbolDiff(UDTRecordEnd, UDTRecordBegin, 2); + OS.EmitLabel(UDTRecordBegin); + + OS.AddComment("Record kind: S_UDT"); + OS.EmitIntValue(unsigned(SymbolKind::S_UDT), 2); + + OS.AddComment("Type"); + OS.EmitIntValue(UDT.second.getIndex(), 4); + + emitNullTerminatedSymbolName(OS, UDT.first); + OS.EmitLabel(UDTRecordEnd); + } +} + +void CodeViewDebug::emitDebugInfoForGlobals() { + NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu"); + for (const MDNode *Node : CUs->operands()) { + const auto *CU = cast<DICompileUnit>(Node); + + // 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); + MCSymbol *EndLabel = nullptr; + for (const DIGlobalVariable *G : CU->getGlobalVariables()) { + if (const auto *GV = dyn_cast_or_null<GlobalVariable>(G->getVariable())) { + if (!GV->hasComdat() && !GV->isDeclarationForLinker()) { + if (!EndLabel) { + OS.AddComment("Symbol subsection for globals"); + EndLabel = beginCVSubsection(ModuleSubstreamKind::Symbols); + } + emitDebugInfoForGlobal(G, Asm->getSymbol(GV)); + } + } + } + if (EndLabel) + 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 DIGlobalVariable *G : CU->getGlobalVariables()) { + if (const auto *GV = dyn_cast_or_null<GlobalVariable>(G->getVariable())) { + if (GV->hasComdat()) { + MCSymbol *GVSym = Asm->getSymbol(GV); + OS.AddComment("Symbol subsection for " + + Twine(GlobalValue::getRealLinkageName(GV->getName()))); + switchToDebugSectionForSymbol(GVSym); + EndLabel = beginCVSubsection(ModuleSubstreamKind::Symbols); + emitDebugInfoForGlobal(G, GVSym); + 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. + } + } + } +} + +void CodeViewDebug::emitDebugInfoForGlobal(const DIGlobalVariable *DIGV, + MCSymbol *GVSym) { + // DataSym record, see SymbolRecord.h for more info. + // FIXME: Thread local data, etc + MCSymbol *DataBegin = MMI->getContext().createTempSymbol(), + *DataEnd = MMI->getContext().createTempSymbol(); + OS.AddComment("Record length"); + OS.emitAbsoluteSymbolDiff(DataEnd, DataBegin, 2); + OS.EmitLabel(DataBegin); + const auto *GV = cast<GlobalVariable>(DIGV->getVariable()); + if (DIGV->isLocalToUnit()) { + if (GV->isThreadLocal()) { + OS.AddComment("Record kind: S_LTHREAD32"); + OS.EmitIntValue(unsigned(SymbolKind::S_LTHREAD32), 2); + } else { + OS.AddComment("Record kind: S_LDATA32"); + OS.EmitIntValue(unsigned(SymbolKind::S_LDATA32), 2); + } + } else { + if (GV->isThreadLocal()) { + OS.AddComment("Record kind: S_GTHREAD32"); + OS.EmitIntValue(unsigned(SymbolKind::S_GTHREAD32), 2); + } else { + OS.AddComment("Record kind: S_GDATA32"); + OS.EmitIntValue(unsigned(SymbolKind::S_GDATA32), 2); + } + } + OS.AddComment("Type"); + OS.EmitIntValue(getCompleteTypeIndex(DIGV->getType()).getIndex(), 4); + OS.AddComment("DataOffset"); + OS.EmitCOFFSecRel32(GVSym); + OS.AddComment("Segment"); + OS.EmitCOFFSectionIndex(GVSym); + OS.AddComment("Name"); + emitNullTerminatedSymbolName(OS, DIGV->getName()); + OS.EmitLabel(DataEnd); +} |