//===-- llvm/CodeGen/DwarfUnit.cpp - Dwarf Type and Compile Units ---------===// // // 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 constructing a dwarf compile unit. // //===----------------------------------------------------------------------===// #include "DwarfUnit.h" #include "AddressPool.h" #include "DwarfCompileUnit.h" #include "DwarfDebug.h" #include "DwarfExpression.h" #include "llvm/ADT/APFloat.h" #include "llvm/ADT/APInt.h" #include "llvm/ADT/None.h" #include "llvm/ADT/StringExtras.h" #include "llvm/ADT/iterator_range.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineOperand.h" #include "llvm/CodeGen/TargetRegisterInfo.h" #include "llvm/CodeGen/TargetSubtargetInfo.h" #include "llvm/IR/Constants.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/GlobalValue.h" #include "llvm/IR/Metadata.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCDwarf.h" #include "llvm/MC/MCSection.h" #include "llvm/MC/MCStreamer.h" #include "llvm/MC/MachineLocation.h" #include "llvm/Support/Casting.h" #include "llvm/Support/CommandLine.h" #include "llvm/Target/TargetLoweringObjectFile.h" #include #include #include #include using namespace llvm; #define DEBUG_TYPE "dwarfdebug" DIEDwarfExpression::DIEDwarfExpression(const AsmPrinter &AP, DwarfCompileUnit &CU, DIELoc &DIE) : DwarfExpression(AP.getDwarfVersion(), CU), AP(AP), OutDIE(DIE) {} void DIEDwarfExpression::emitOp(uint8_t Op, const char* Comment) { CU.addUInt(getActiveDIE(), dwarf::DW_FORM_data1, Op); } void DIEDwarfExpression::emitSigned(int64_t Value) { CU.addSInt(getActiveDIE(), dwarf::DW_FORM_sdata, Value); } void DIEDwarfExpression::emitUnsigned(uint64_t Value) { CU.addUInt(getActiveDIE(), dwarf::DW_FORM_udata, Value); } void DIEDwarfExpression::emitData1(uint8_t Value) { CU.addUInt(getActiveDIE(), dwarf::DW_FORM_data1, Value); } void DIEDwarfExpression::emitBaseTypeRef(uint64_t Idx) { CU.addBaseTypeRef(getActiveDIE(), Idx); } void DIEDwarfExpression::enableTemporaryBuffer() { assert(!IsBuffering && "Already buffering?"); IsBuffering = true; } void DIEDwarfExpression::disableTemporaryBuffer() { IsBuffering = false; } unsigned DIEDwarfExpression::getTemporaryBufferSize() { return TmpDIE.ComputeSize(&AP); } void DIEDwarfExpression::commitTemporaryBuffer() { OutDIE.takeValues(TmpDIE); } bool DIEDwarfExpression::isFrameRegister(const TargetRegisterInfo &TRI, unsigned MachineReg) { return MachineReg == TRI.getFrameRegister(*AP.MF); } DwarfUnit::DwarfUnit(dwarf::Tag UnitTag, const DICompileUnit *Node, AsmPrinter *A, DwarfDebug *DW, DwarfFile *DWU) : DIEUnit(A->getDwarfVersion(), A->MAI->getCodePointerSize(), UnitTag), CUNode(Node), Asm(A), DD(DW), DU(DWU), IndexTyDie(nullptr) { } DwarfTypeUnit::DwarfTypeUnit(DwarfCompileUnit &CU, AsmPrinter *A, DwarfDebug *DW, DwarfFile *DWU, MCDwarfDwoLineTable *SplitLineTable) : DwarfUnit(dwarf::DW_TAG_type_unit, CU.getCUNode(), A, DW, DWU), CU(CU), SplitLineTable(SplitLineTable) { } DwarfUnit::~DwarfUnit() { for (unsigned j = 0, M = DIEBlocks.size(); j < M; ++j) DIEBlocks[j]->~DIEBlock(); for (unsigned j = 0, M = DIELocs.size(); j < M; ++j) DIELocs[j]->~DIELoc(); } int64_t DwarfUnit::getDefaultLowerBound() const { switch (getLanguage()) { default: break; // The languages below have valid values in all DWARF versions. case dwarf::DW_LANG_C: case dwarf::DW_LANG_C89: case dwarf::DW_LANG_C_plus_plus: return 0; case dwarf::DW_LANG_Fortran77: case dwarf::DW_LANG_Fortran90: return 1; // The languages below have valid values only if the DWARF version >= 3. case dwarf::DW_LANG_C99: case dwarf::DW_LANG_ObjC: case dwarf::DW_LANG_ObjC_plus_plus: if (DD->getDwarfVersion() >= 3) return 0; break; case dwarf::DW_LANG_Fortran95: if (DD->getDwarfVersion() >= 3) return 1; break; // Starting with DWARF v4, all defined languages have valid values. case dwarf::DW_LANG_D: case dwarf::DW_LANG_Java: case dwarf::DW_LANG_Python: case dwarf::DW_LANG_UPC: if (DD->getDwarfVersion() >= 4) return 0; break; case dwarf::DW_LANG_Ada83: case dwarf::DW_LANG_Ada95: case dwarf::DW_LANG_Cobol74: case dwarf::DW_LANG_Cobol85: case dwarf::DW_LANG_Modula2: case dwarf::DW_LANG_Pascal83: case dwarf::DW_LANG_PLI: if (DD->getDwarfVersion() >= 4) return 1; break; // The languages below are new in DWARF v5. case dwarf::DW_LANG_BLISS: case dwarf::DW_LANG_C11: case dwarf::DW_LANG_C_plus_plus_03: case dwarf::DW_LANG_C_plus_plus_11: case dwarf::DW_LANG_C_plus_plus_14: case dwarf::DW_LANG_Dylan: case dwarf::DW_LANG_Go: case dwarf::DW_LANG_Haskell: case dwarf::DW_LANG_OCaml: case dwarf::DW_LANG_OpenCL: case dwarf::DW_LANG_RenderScript: case dwarf::DW_LANG_Rust: case dwarf::DW_LANG_Swift: if (DD->getDwarfVersion() >= 5) return 0; break; case dwarf::DW_LANG_Fortran03: case dwarf::DW_LANG_Fortran08: case dwarf::DW_LANG_Julia: case dwarf::DW_LANG_Modula3: if (DD->getDwarfVersion() >= 5) return 1; break; } return -1; } /// Check whether the DIE for this MDNode can be shared across CUs. bool DwarfUnit::isShareableAcrossCUs(const DINode *D) const { // When the MDNode can be part of the type system (this includes subprogram // declarations *and* subprogram definitions, even local definitions), the // DIE must be shared across CUs. // Combining type units and cross-CU DIE sharing is lower value (since // cross-CU DIE sharing is used in LTO and removes type redundancy at that // level already) but may be implementable for some value in projects // building multiple independent libraries with LTO and then linking those // together. if (isDwoUnit() && !DD->shareAcrossDWOCUs()) return false; return (isa(D) || isa(D)) && !DD->generateTypeUnits(); } DIE *DwarfUnit::getDIE(const DINode *D) const { if (isShareableAcrossCUs(D)) return DU->getDIE(D); return MDNodeToDieMap.lookup(D); } void DwarfUnit::insertDIE(const DINode *Desc, DIE *D) { if (isShareableAcrossCUs(Desc)) { DU->insertDIE(Desc, D); return; } MDNodeToDieMap.insert(std::make_pair(Desc, D)); } void DwarfUnit::insertDIE(DIE *D) { MDNodeToDieMap.insert(std::make_pair(nullptr, D)); } void DwarfUnit::addFlag(DIE &Die, dwarf::Attribute Attribute) { if (DD->getDwarfVersion() >= 4) Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_flag_present, DIEInteger(1)); else Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_flag, DIEInteger(1)); } void DwarfUnit::addUInt(DIEValueList &Die, dwarf::Attribute Attribute, Optional Form, uint64_t Integer) { if (!Form) Form = DIEInteger::BestForm(false, Integer); assert(Form != dwarf::DW_FORM_implicit_const && "DW_FORM_implicit_const is used only for signed integers"); Die.addValue(DIEValueAllocator, Attribute, *Form, DIEInteger(Integer)); } void DwarfUnit::addUInt(DIEValueList &Block, dwarf::Form Form, uint64_t Integer) { addUInt(Block, (dwarf::Attribute)0, Form, Integer); } void DwarfUnit::addSInt(DIEValueList &Die, dwarf::Attribute Attribute, Optional Form, int64_t Integer) { if (!Form) Form = DIEInteger::BestForm(true, Integer); Die.addValue(DIEValueAllocator, Attribute, *Form, DIEInteger(Integer)); } void DwarfUnit::addSInt(DIELoc &Die, Optional Form, int64_t Integer) { addSInt(Die, (dwarf::Attribute)0, Form, Integer); } void DwarfUnit::addString(DIE &Die, dwarf::Attribute Attribute, StringRef String) { if (CUNode->isDebugDirectivesOnly()) return; if (DD->useInlineStrings()) { Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_string, new (DIEValueAllocator) DIEInlineString(String, DIEValueAllocator)); return; } dwarf::Form IxForm = isDwoUnit() ? dwarf::DW_FORM_GNU_str_index : dwarf::DW_FORM_strp; auto StringPoolEntry = useSegmentedStringOffsetsTable() || IxForm == dwarf::DW_FORM_GNU_str_index ? DU->getStringPool().getIndexedEntry(*Asm, String) : DU->getStringPool().getEntry(*Asm, String); // For DWARF v5 and beyond, use the smallest strx? form possible. if (useSegmentedStringOffsetsTable()) { IxForm = dwarf::DW_FORM_strx1; unsigned Index = StringPoolEntry.getIndex(); if (Index > 0xffffff) IxForm = dwarf::DW_FORM_strx4; else if (Index > 0xffff) IxForm = dwarf::DW_FORM_strx3; else if (Index > 0xff) IxForm = dwarf::DW_FORM_strx2; } Die.addValue(DIEValueAllocator, Attribute, IxForm, DIEString(StringPoolEntry)); } DIEValueList::value_iterator DwarfUnit::addLabel(DIEValueList &Die, dwarf::Attribute Attribute, dwarf::Form Form, const MCSymbol *Label) { return Die.addValue(DIEValueAllocator, Attribute, Form, DIELabel(Label)); } void DwarfUnit::addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label) { addLabel(Die, (dwarf::Attribute)0, Form, Label); } void DwarfUnit::addSectionOffset(DIE &Die, dwarf::Attribute Attribute, uint64_t Integer) { if (DD->getDwarfVersion() >= 4) addUInt(Die, Attribute, dwarf::DW_FORM_sec_offset, Integer); else addUInt(Die, Attribute, dwarf::DW_FORM_data4, Integer); } Optional DwarfUnit::getMD5AsBytes(const DIFile *File) const { assert(File); if (DD->getDwarfVersion() < 5) return None; Optional> Checksum = File->getChecksum(); if (!Checksum || Checksum->Kind != DIFile::CSK_MD5) return None; // Convert the string checksum to an MD5Result for the streamer. // The verifier validates the checksum so we assume it's okay. // An MD5 checksum is 16 bytes. std::string ChecksumString = fromHex(Checksum->Value); MD5::MD5Result CKMem; std::copy(ChecksumString.begin(), ChecksumString.end(), CKMem.Bytes.data()); return CKMem; } unsigned DwarfTypeUnit::getOrCreateSourceID(const DIFile *File) { if (!SplitLineTable) return getCU().getOrCreateSourceID(File); if (!UsedLineTable) { UsedLineTable = true; // This is a split type unit that needs a line table. addSectionOffset(getUnitDie(), dwarf::DW_AT_stmt_list, 0); } return SplitLineTable->getFile(File->getDirectory(), File->getFilename(), getMD5AsBytes(File), Asm->OutContext.getDwarfVersion(), File->getSource()); } void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) { if (DD->getDwarfVersion() >= 5) { addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addrx); addUInt(Die, dwarf::DW_FORM_addrx, DD->getAddressPool().getIndex(Sym)); return; } if (DD->useSplitDwarf()) { addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_addr_index); addUInt(Die, dwarf::DW_FORM_GNU_addr_index, DD->getAddressPool().getIndex(Sym)); return; } addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addr); addLabel(Die, dwarf::DW_FORM_udata, Sym); } void DwarfUnit::addLabelDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi, const MCSymbol *Lo) { Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_data4, new (DIEValueAllocator) DIEDelta(Hi, Lo)); } void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry) { addDIEEntry(Die, Attribute, DIEEntry(Entry)); } void DwarfUnit::addDIETypeSignature(DIE &Die, uint64_t Signature) { // Flag the type unit reference as a declaration so that if it contains // members (implicit special members, static data member definitions, member // declarations for definitions in this CU, etc) consumers don't get confused // and think this is a full definition. addFlag(Die, dwarf::DW_AT_declaration); Die.addValue(DIEValueAllocator, dwarf::DW_AT_signature, dwarf::DW_FORM_ref_sig8, DIEInteger(Signature)); } void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry Entry) { const DIEUnit *CU = Die.getUnit(); const DIEUnit *EntryCU = Entry.getEntry().getUnit(); if (!CU) // We assume that Die belongs to this CU, if it is not linked to any CU yet. CU = getUnitDie().getUnit(); if (!EntryCU) EntryCU = getUnitDie().getUnit(); Die.addValue(DIEValueAllocator, Attribute, EntryCU == CU ? dwarf::DW_FORM_ref4 : dwarf::DW_FORM_ref_addr, Entry); } DIE &DwarfUnit::createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N) { DIE &Die = Parent.addChild(DIE::get(DIEValueAllocator, (dwarf::Tag)Tag)); if (N) insertDIE(N, &Die); return Die; } void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Loc) { Loc->ComputeSize(Asm); DIELocs.push_back(Loc); // Memoize so we can call the destructor later on. Die.addValue(DIEValueAllocator, Attribute, Loc->BestForm(DD->getDwarfVersion()), Loc); } void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block) { Block->ComputeSize(Asm); DIEBlocks.push_back(Block); // Memoize so we can call the destructor later on. Die.addValue(DIEValueAllocator, Attribute, Block->BestForm(), Block); } void DwarfUnit::addSourceLine(DIE &Die, unsigned Line, const DIFile *File) { if (Line == 0) return; unsigned FileID = getOrCreateSourceID(File); addUInt(Die, dwarf::DW_AT_decl_file, None, FileID); addUInt(Die, dwarf::DW_AT_decl_line, None, Line); } void DwarfUnit::addSourceLine(DIE &Die, const DILocalVariable *V) { assert(V); addSourceLine(Die, V->getLine(), V->getFile()); } void DwarfUnit::addSourceLine(DIE &Die, const DIGlobalVariable *G) { assert(G); addSourceLine(Die, G->getLine(), G->getFile()); } void DwarfUnit::addSourceLine(DIE &Die, const DISubprogram *SP) { assert(SP); addSourceLine(Die, SP->getLine(), SP->getFile()); } void DwarfUnit::addSourceLine(DIE &Die, const DILabel *L) { assert(L); addSourceLine(Die, L->getLine(), L->getFile()); } void DwarfUnit::addSourceLine(DIE &Die, const DIType *Ty) { assert(Ty); addSourceLine(Die, Ty->getLine(), Ty->getFile()); } void DwarfUnit::addSourceLine(DIE &Die, const DIObjCProperty *Ty) { assert(Ty); addSourceLine(Die, Ty->getLine(), Ty->getFile()); } /// Return true if type encoding is unsigned. static bool isUnsignedDIType(DwarfDebug *DD, const DIType *Ty) { if (auto *CTy = dyn_cast(Ty)) { // FIXME: Enums without a fixed underlying type have unknown signedness // here, leading to incorrectly emitted constants. if (CTy->getTag() == dwarf::DW_TAG_enumeration_type) return false; // (Pieces of) aggregate types that get hacked apart by SROA may be // represented by a constant. Encode them as unsigned bytes. return true; } if (auto *DTy = dyn_cast(Ty)) { dwarf::Tag T = (dwarf::Tag)Ty->getTag(); // Encode pointer constants as unsigned bytes. This is used at least for // null pointer constant emission. // FIXME: reference and rvalue_reference /probably/ shouldn't be allowed // here, but accept them for now due to a bug in SROA producing bogus // dbg.values. 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 true; assert(T == dwarf::DW_TAG_typedef || T == dwarf::DW_TAG_const_type || T == dwarf::DW_TAG_volatile_type || T == dwarf::DW_TAG_restrict_type || T == dwarf::DW_TAG_atomic_type); assert(DTy->getBaseType() && "Expected valid base type"); return isUnsignedDIType(DD, DTy->getBaseType()); } auto *BTy = cast(Ty); unsigned Encoding = BTy->getEncoding(); assert((Encoding == dwarf::DW_ATE_unsigned || Encoding == dwarf::DW_ATE_unsigned_char || Encoding == dwarf::DW_ATE_signed || Encoding == dwarf::DW_ATE_signed_char || Encoding == dwarf::DW_ATE_float || Encoding == dwarf::DW_ATE_UTF || Encoding == dwarf::DW_ATE_boolean || (Ty->getTag() == dwarf::DW_TAG_unspecified_type && Ty->getName() == "decltype(nullptr)")) && "Unsupported encoding"); return Encoding == dwarf::DW_ATE_unsigned || Encoding == dwarf::DW_ATE_unsigned_char || Encoding == dwarf::DW_ATE_UTF || Encoding == dwarf::DW_ATE_boolean || Ty->getTag() == dwarf::DW_TAG_unspecified_type; } void DwarfUnit::addConstantFPValue(DIE &Die, const MachineOperand &MO) { assert(MO.isFPImm() && "Invalid machine operand!"); DIEBlock *Block = new (DIEValueAllocator) DIEBlock; APFloat FPImm = MO.getFPImm()->getValueAPF(); // Get the raw data form of the floating point. const APInt FltVal = FPImm.bitcastToAPInt(); const char *FltPtr = (const char *)FltVal.getRawData(); int NumBytes = FltVal.getBitWidth() / 8; // 8 bits per byte. bool LittleEndian = Asm->getDataLayout().isLittleEndian(); int Incr = (LittleEndian ? 1 : -1); int Start = (LittleEndian ? 0 : NumBytes - 1); int Stop = (LittleEndian ? NumBytes : -1); // Output the constant to DWARF one byte at a time. for (; Start != Stop; Start += Incr) addUInt(*Block, dwarf::DW_FORM_data1, (unsigned char)0xFF & FltPtr[Start]); addBlock(Die, dwarf::DW_AT_const_value, Block); } void DwarfUnit::addConstantFPValue(DIE &Die, const ConstantFP *CFP) { // Pass this down to addConstantValue as an unsigned bag of bits. addConstantValue(Die, CFP->getValueAPF().bitcastToAPInt(), true); } void DwarfUnit::addConstantValue(DIE &Die, const ConstantInt *CI, const DIType *Ty) { addConstantValue(Die, CI->getValue(), Ty); } void DwarfUnit::addConstantValue(DIE &Die, const MachineOperand &MO, const DIType *Ty) { assert(MO.isImm() && "Invalid machine operand!"); addConstantValue(Die, isUnsignedDIType(DD, Ty), MO.getImm()); } void DwarfUnit::addConstantValue(DIE &Die, uint64_t Val, const DIType *Ty) { addConstantValue(Die, isUnsignedDIType(DD, Ty), Val); } void DwarfUnit::addConstantValue(DIE &Die, bool Unsigned, uint64_t Val) { // FIXME: This is a bit conservative/simple - it emits negative values always // sign extended to 64 bits rather than minimizing the number of bytes. addUInt(Die, dwarf::DW_AT_const_value, Unsigned ? dwarf::DW_FORM_udata : dwarf::DW_FORM_sdata, Val); } void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty) { addConstantValue(Die, Val, isUnsignedDIType(DD, Ty)); } void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, bool Unsigned) { unsigned CIBitWidth = Val.getBitWidth(); if (CIBitWidth <= 64) { addConstantValue(Die, Unsigned, Unsigned ? Val.getZExtValue() : Val.getSExtValue()); return; } DIEBlock *Block = new (DIEValueAllocator) DIEBlock; // Get the raw data form of the large APInt. const uint64_t *Ptr64 = Val.getRawData(); int NumBytes = Val.getBitWidth() / 8; // 8 bits per byte. bool LittleEndian = Asm->getDataLayout().isLittleEndian(); // Output the constant to DWARF one byte at a time. for (int i = 0; i < NumBytes; i++) { uint8_t c; if (LittleEndian) c = Ptr64[i / 8] >> (8 * (i & 7)); else c = Ptr64[(NumBytes - 1 - i) / 8] >> (8 * ((NumBytes - 1 - i) & 7)); addUInt(*Block, dwarf::DW_FORM_data1, c); } addBlock(Die, dwarf::DW_AT_const_value, Block); } void DwarfUnit::addLinkageName(DIE &Die, StringRef LinkageName) { if (!LinkageName.empty()) addString(Die, DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name : dwarf::DW_AT_MIPS_linkage_name, GlobalValue::dropLLVMManglingEscape(LinkageName)); } void DwarfUnit::addTemplateParams(DIE &Buffer, DINodeArray TParams) { // Add template parameters. for (const auto *Element : TParams) { if (auto *TTP = dyn_cast(Element)) constructTemplateTypeParameterDIE(Buffer, TTP); else if (auto *TVP = dyn_cast(Element)) constructTemplateValueParameterDIE(Buffer, TVP); } } /// Add thrown types. void DwarfUnit::addThrownTypes(DIE &Die, DINodeArray ThrownTypes) { for (const auto *Ty : ThrownTypes) { DIE &TT = createAndAddDIE(dwarf::DW_TAG_thrown_type, Die); addType(TT, cast(Ty)); } } DIE *DwarfUnit::getOrCreateContextDIE(const DIScope *Context) { if (!Context || isa(Context)) return &getUnitDie(); if (auto *T = dyn_cast(Context)) return getOrCreateTypeDIE(T); if (auto *NS = dyn_cast(Context)) return getOrCreateNameSpace(NS); if (auto *SP = dyn_cast(Context)) return getOrCreateSubprogramDIE(SP); if (auto *M = dyn_cast(Context)) return getOrCreateModule(M); return getDIE(Context); } DIE *DwarfUnit::createTypeDIE(const DICompositeType *Ty) { auto *Context = Ty->getScope(); DIE *ContextDIE = getOrCreateContextDIE(Context); if (DIE *TyDIE = getDIE(Ty)) return TyDIE; // Create new type. DIE &TyDIE = createAndAddDIE(Ty->getTag(), *ContextDIE, Ty); constructTypeDIE(TyDIE, cast(Ty)); updateAcceleratorTables(Context, Ty, TyDIE); return &TyDIE; } DIE *DwarfUnit::createTypeDIE(const DIScope *Context, DIE &ContextDIE, const DIType *Ty) { // Create new type. DIE &TyDIE = createAndAddDIE(Ty->getTag(), ContextDIE, Ty); updateAcceleratorTables(Context, Ty, TyDIE); if (auto *BT = dyn_cast(Ty)) constructTypeDIE(TyDIE, BT); else if (auto *STy = dyn_cast(Ty)) constructTypeDIE(TyDIE, STy); else if (auto *CTy = dyn_cast(Ty)) { if (DD->generateTypeUnits() && !Ty->isForwardDecl() && (Ty->getRawName() || CTy->getRawIdentifier())) { // Skip updating the accelerator tables since this is not the full type. if (MDString *TypeId = CTy->getRawIdentifier()) DD->addDwarfTypeUnitType(getCU(), TypeId->getString(), TyDIE, CTy); else { auto X = DD->enterNonTypeUnitContext(); finishNonUnitTypeDIE(TyDIE, CTy); } return &TyDIE; } constructTypeDIE(TyDIE, CTy); } else { constructTypeDIE(TyDIE, cast(Ty)); } return &TyDIE; } DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) { if (!TyNode) return nullptr; auto *Ty = cast(TyNode); // DW_TAG_restrict_type is not supported in DWARF2 if (Ty->getTag() == dwarf::DW_TAG_restrict_type && DD->getDwarfVersion() <= 2) return getOrCreateTypeDIE(cast(Ty)->getBaseType()); // DW_TAG_atomic_type is not supported in DWARF < 5 if (Ty->getTag() == dwarf::DW_TAG_atomic_type && DD->getDwarfVersion() < 5) return getOrCreateTypeDIE(cast(Ty)->getBaseType()); // Construct the context before querying for the existence of the DIE in case // such construction creates the DIE. auto *Context = Ty->getScope(); DIE *ContextDIE = getOrCreateContextDIE(Context); assert(ContextDIE); if (DIE *TyDIE = getDIE(Ty)) return TyDIE; return static_cast(ContextDIE->getUnit()) ->createTypeDIE(Context, *ContextDIE, Ty); } void DwarfUnit::updateAcceleratorTables(const DIScope *Context, const DIType *Ty, const DIE &TyDIE) { if (!Ty->getName().empty() && !Ty->isForwardDecl()) { bool IsImplementation = false; if (auto *CT = dyn_cast(Ty)) { // A runtime language of 0 actually means C/C++ and that any // non-negative value is some version of Objective-C/C++. IsImplementation = CT->getRuntimeLang() == 0 || CT->isObjcClassComplete(); } unsigned Flags = IsImplementation ? dwarf::DW_FLAG_type_implementation : 0; DD->addAccelType(*CUNode, Ty->getName(), TyDIE, Flags); if (!Context || isa(Context) || isa(Context) || isa(Context) || isa(Context)) addGlobalType(Ty, TyDIE, Context); } } void DwarfUnit::addType(DIE &Entity, const DIType *Ty, dwarf::Attribute Attribute) { assert(Ty && "Trying to add a type that doesn't exist?"); addDIEEntry(Entity, Attribute, DIEEntry(*getOrCreateTypeDIE(Ty))); } std::string DwarfUnit::getParentContextString(const DIScope *Context) const { if (!Context) return ""; // FIXME: Decide whether to implement this for non-C++ languages. if (!dwarf::isCPlusPlus((dwarf::SourceLanguage)getLanguage())) return ""; std::string CS; SmallVector Parents; while (!isa(Context)) { Parents.push_back(Context); if (const DIScope *S = Context->getScope()) Context = S; else // Structure, etc types will have a NULL context if they're at the top // level. break; } // Reverse iterate over our list to go from the outermost construct to the // innermost. for (const DIScope *Ctx : make_range(Parents.rbegin(), Parents.rend())) { StringRef Name = Ctx->getName(); if (Name.empty() && isa(Ctx)) Name = "(anonymous namespace)"; if (!Name.empty()) { CS += Name; CS += "::"; } } return CS; } void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIBasicType *BTy) { // Get core information. StringRef Name = BTy->getName(); // Add name if not anonymous or intermediate type. if (!Name.empty()) addString(Buffer, dwarf::DW_AT_name, Name); // An unspecified type only has a name attribute. if (BTy->getTag() == dwarf::DW_TAG_unspecified_type) return; addUInt(Buffer, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1, BTy->getEncoding()); uint64_t Size = BTy->getSizeInBits() >> 3; addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size); if (BTy->isBigEndian()) addUInt(Buffer, dwarf::DW_AT_endianity, None, dwarf::DW_END_big); else if (BTy->isLittleEndian()) addUInt(Buffer, dwarf::DW_AT_endianity, None, dwarf::DW_END_little); } void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy) { // Get core information. StringRef Name = DTy->getName(); uint64_t Size = DTy->getSizeInBits() >> 3; uint16_t Tag = Buffer.getTag(); // Map to main type, void will not have a type. const DIType *FromTy = DTy->getBaseType(); if (FromTy) addType(Buffer, FromTy); // Add name if not anonymous or intermediate type. if (!Name.empty()) addString(Buffer, dwarf::DW_AT_name, Name); // If alignment is specified for a typedef , create and insert DW_AT_alignment // attribute in DW_TAG_typedef DIE. if (Tag == dwarf::DW_TAG_typedef && DD->getDwarfVersion() >= 5) { uint32_t AlignInBytes = DTy->getAlignInBytes(); if (AlignInBytes > 0) addUInt(Buffer, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata, AlignInBytes); } // Add size if non-zero (derived types might be zero-sized.) if (Size && Tag != dwarf::DW_TAG_pointer_type && Tag != dwarf::DW_TAG_ptr_to_member_type && Tag != dwarf::DW_TAG_reference_type && Tag != dwarf::DW_TAG_rvalue_reference_type) addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size); if (Tag == dwarf::DW_TAG_ptr_to_member_type) addDIEEntry(Buffer, dwarf::DW_AT_containing_type, *getOrCreateTypeDIE(cast(DTy)->getClassType())); // Add source line info if available and TyDesc is not a forward declaration. if (!DTy->isForwardDecl()) addSourceLine(Buffer, DTy); // If DWARF address space value is other than None, add it. The IR // verifier checks that DWARF address space only exists for pointer // or reference types. if (DTy->getDWARFAddressSpace()) addUInt(Buffer, dwarf::DW_AT_address_class, dwarf::DW_FORM_data4, DTy->getDWARFAddressSpace().getValue()); } void DwarfUnit::constructSubprogramArguments(DIE &Buffer, DITypeRefArray Args) { for (unsigned i = 1, N = Args.size(); i < N; ++i) { const DIType *Ty = Args[i]; if (!Ty) { assert(i == N-1 && "Unspecified parameter must be the last argument"); createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer); } else { DIE &Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer); addType(Arg, Ty); if (Ty->isArtificial()) addFlag(Arg, dwarf::DW_AT_artificial); } } } void DwarfUnit::constructTypeDIE(DIE &Buffer, const DISubroutineType *CTy) { // Add return type. A void return won't have a type. auto Elements = cast(CTy)->getTypeArray(); if (Elements.size()) if (auto RTy = Elements[0]) addType(Buffer, RTy); bool isPrototyped = true; if (Elements.size() == 2 && !Elements[1]) isPrototyped = false; constructSubprogramArguments(Buffer, Elements); // Add prototype flag if we're dealing with a C language and the function has // been prototyped. uint16_t Language = getLanguage(); if (isPrototyped && (Language == dwarf::DW_LANG_C89 || Language == dwarf::DW_LANG_C99 || Language == dwarf::DW_LANG_ObjC)) addFlag(Buffer, dwarf::DW_AT_prototyped); // Add a DW_AT_calling_convention if this has an explicit convention. if (CTy->getCC() && CTy->getCC() != dwarf::DW_CC_normal) addUInt(Buffer, dwarf::DW_AT_calling_convention, dwarf::DW_FORM_data1, CTy->getCC()); if (CTy->isLValueReference()) addFlag(Buffer, dwarf::DW_AT_reference); if (CTy->isRValueReference()) addFlag(Buffer, dwarf::DW_AT_rvalue_reference); } void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) { // Add name if not anonymous or intermediate type. StringRef Name = CTy->getName(); uint64_t Size = CTy->getSizeInBits() >> 3; uint16_t Tag = Buffer.getTag(); switch (Tag) { case dwarf::DW_TAG_array_type: constructArrayTypeDIE(Buffer, CTy); break; case dwarf::DW_TAG_enumeration_type: constructEnumTypeDIE(Buffer, CTy); break; case dwarf::DW_TAG_variant_part: case dwarf::DW_TAG_structure_type: case dwarf::DW_TAG_union_type: case dwarf::DW_TAG_class_type: { // Emit the discriminator for a variant part. DIDerivedType *Discriminator = nullptr; if (Tag == dwarf::DW_TAG_variant_part) { Discriminator = CTy->getDiscriminator(); if (Discriminator) { // DWARF says: // If the variant part has a discriminant, the discriminant is // represented by a separate debugging information entry which is // a child of the variant part entry. DIE &DiscMember = constructMemberDIE(Buffer, Discriminator); addDIEEntry(Buffer, dwarf::DW_AT_discr, DiscMember); } } // Add elements to structure type. DINodeArray Elements = CTy->getElements(); for (const auto *Element : Elements) { if (!Element) continue; if (auto *SP = dyn_cast(Element)) getOrCreateSubprogramDIE(SP); else if (auto *DDTy = dyn_cast(Element)) { if (DDTy->getTag() == dwarf::DW_TAG_friend) { DIE &ElemDie = createAndAddDIE(dwarf::DW_TAG_friend, Buffer); addType(ElemDie, DDTy->getBaseType(), dwarf::DW_AT_friend); } else if (DDTy->isStaticMember()) { getOrCreateStaticMemberDIE(DDTy); } else if (Tag == dwarf::DW_TAG_variant_part) { // When emitting a variant part, wrap each member in // DW_TAG_variant. DIE &Variant = createAndAddDIE(dwarf::DW_TAG_variant, Buffer); if (const ConstantInt *CI = dyn_cast_or_null(DDTy->getDiscriminantValue())) { if (isUnsignedDIType(DD, Discriminator->getBaseType())) addUInt(Variant, dwarf::DW_AT_discr_value, None, CI->getZExtValue()); else addSInt(Variant, dwarf::DW_AT_discr_value, None, CI->getSExtValue()); } constructMemberDIE(Variant, DDTy); } else { constructMemberDIE(Buffer, DDTy); } } else if (auto *Property = dyn_cast(Element)) { DIE &ElemDie = createAndAddDIE(Property->getTag(), Buffer); StringRef PropertyName = Property->getName(); addString(ElemDie, dwarf::DW_AT_APPLE_property_name, PropertyName); if (Property->getType()) addType(ElemDie, Property->getType()); addSourceLine(ElemDie, Property); StringRef GetterName = Property->getGetterName(); if (!GetterName.empty()) addString(ElemDie, dwarf::DW_AT_APPLE_property_getter, GetterName); StringRef SetterName = Property->getSetterName(); if (!SetterName.empty()) addString(ElemDie, dwarf::DW_AT_APPLE_property_setter, SetterName); if (unsigned PropertyAttributes = Property->getAttributes()) addUInt(ElemDie, dwarf::DW_AT_APPLE_property_attribute, None, PropertyAttributes); } else if (auto *Composite = dyn_cast(Element)) { if (Composite->getTag() == dwarf::DW_TAG_variant_part) { DIE &VariantPart = createAndAddDIE(Composite->getTag(), Buffer); constructTypeDIE(VariantPart, Composite); } } } if (CTy->isAppleBlockExtension()) addFlag(Buffer, dwarf::DW_AT_APPLE_block); if (CTy->getExportSymbols()) addFlag(Buffer, dwarf::DW_AT_export_symbols); // This is outside the DWARF spec, but GDB expects a DW_AT_containing_type // inside C++ composite types to point to the base class with the vtable. // Rust uses DW_AT_containing_type to link a vtable to the type // for which it was created. if (auto *ContainingType = CTy->getVTableHolder()) addDIEEntry(Buffer, dwarf::DW_AT_containing_type, *getOrCreateTypeDIE(ContainingType)); if (CTy->isObjcClassComplete()) addFlag(Buffer, dwarf::DW_AT_APPLE_objc_complete_type); // Add template parameters to a class, structure or union types. // FIXME: The support isn't in the metadata for this yet. if (Tag == dwarf::DW_TAG_class_type || Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type) addTemplateParams(Buffer, CTy->getTemplateParams()); // Add the type's non-standard calling convention. uint8_t CC = 0; if (CTy->isTypePassByValue()) CC = dwarf::DW_CC_pass_by_value; else if (CTy->isTypePassByReference()) CC = dwarf::DW_CC_pass_by_reference; if (CC) addUInt(Buffer, dwarf::DW_AT_calling_convention, dwarf::DW_FORM_data1, CC); break; } default: break; } // Add name if not anonymous or intermediate type. if (!Name.empty()) addString(Buffer, dwarf::DW_AT_name, Name); if (Tag == dwarf::DW_TAG_enumeration_type || Tag == dwarf::DW_TAG_class_type || Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type) { // Add size if non-zero (derived types might be zero-sized.) // TODO: Do we care about size for enum forward declarations? if (Size) addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size); else if (!CTy->isForwardDecl()) // Add zero size if it is not a forward declaration. addUInt(Buffer, dwarf::DW_AT_byte_size, None, 0); // If we're a forward decl, say so. if (CTy->isForwardDecl()) addFlag(Buffer, dwarf::DW_AT_declaration); // Add source line info if available. if (!CTy->isForwardDecl()) addSourceLine(Buffer, CTy); // No harm in adding the runtime language to the declaration. unsigned RLang = CTy->getRuntimeLang(); if (RLang) addUInt(Buffer, dwarf::DW_AT_APPLE_runtime_class, dwarf::DW_FORM_data1, RLang); // Add align info if available. if (uint32_t AlignInBytes = CTy->getAlignInBytes()) addUInt(Buffer, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata, AlignInBytes); } } void DwarfUnit::constructTemplateTypeParameterDIE( DIE &Buffer, const DITemplateTypeParameter *TP) { DIE &ParamDIE = createAndAddDIE(dwarf::DW_TAG_template_type_parameter, Buffer); // Add the type if it exists, it could be void and therefore no type. if (TP->getType()) addType(ParamDIE, TP->getType()); if (!TP->getName().empty()) addString(ParamDIE, dwarf::DW_AT_name, TP->getName()); if (TP->isDefault() && (DD->getDwarfVersion() >= 5)) addFlag(ParamDIE, dwarf::DW_AT_default_value); } void DwarfUnit::constructTemplateValueParameterDIE( DIE &Buffer, const DITemplateValueParameter *VP) { DIE &ParamDIE = createAndAddDIE(VP->getTag(), Buffer); // Add the type if there is one, template template and template parameter // packs will not have a type. if (VP->getTag() == dwarf::DW_TAG_template_value_parameter) addType(ParamDIE, VP->getType()); if (!VP->getName().empty()) addString(ParamDIE, dwarf::DW_AT_name, VP->getName()); if (VP->isDefault() && (DD->getDwarfVersion() >= 5)) addFlag(ParamDIE, dwarf::DW_AT_default_value); if (Metadata *Val = VP->getValue()) { if (ConstantInt *CI = mdconst::dyn_extract(Val)) addConstantValue(ParamDIE, CI, VP->getType()); else if (GlobalValue *GV = mdconst::dyn_extract(Val)) { // We cannot describe the location of dllimport'd entities: the // computation of their address requires loads from the IAT. if (!GV->hasDLLImportStorageClass()) { // For declaration non-type template parameters (such as global values // and functions) DIELoc *Loc = new (DIEValueAllocator) DIELoc; addOpAddress(*Loc, Asm->getSymbol(GV)); // Emit DW_OP_stack_value to use the address as the immediate value of // the parameter, rather than a pointer to it. addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value); addBlock(ParamDIE, dwarf::DW_AT_location, Loc); } } else if (VP->getTag() == dwarf::DW_TAG_GNU_template_template_param) { assert(isa(Val)); addString(ParamDIE, dwarf::DW_AT_GNU_template_name, cast(Val)->getString()); } else if (VP->getTag() == dwarf::DW_TAG_GNU_template_parameter_pack) { addTemplateParams(ParamDIE, cast(Val)); } } } DIE *DwarfUnit::getOrCreateNameSpace(const DINamespace *NS) { // Construct the context before querying for the existence of the DIE in case // such construction creates the DIE. DIE *ContextDIE = getOrCreateContextDIE(NS->getScope()); if (DIE *NDie = getDIE(NS)) return NDie; DIE &NDie = createAndAddDIE(dwarf::DW_TAG_namespace, *ContextDIE, NS); StringRef Name = NS->getName(); if (!Name.empty()) addString(NDie, dwarf::DW_AT_name, NS->getName()); else Name = "(anonymous namespace)"; DD->addAccelNamespace(*CUNode, Name, NDie); addGlobalName(Name, NDie, NS->getScope()); if (NS->getExportSymbols()) addFlag(NDie, dwarf::DW_AT_export_symbols); return &NDie; } DIE *DwarfUnit::getOrCreateModule(const DIModule *M) { // Construct the context before querying for the existence of the DIE in case // such construction creates the DIE. DIE *ContextDIE = getOrCreateContextDIE(M->getScope()); if (DIE *MDie = getDIE(M)) return MDie; DIE &MDie = createAndAddDIE(dwarf::DW_TAG_module, *ContextDIE, M); if (!M->getName().empty()) { addString(MDie, dwarf::DW_AT_name, M->getName()); addGlobalName(M->getName(), MDie, M->getScope()); } if (!M->getConfigurationMacros().empty()) addString(MDie, dwarf::DW_AT_LLVM_config_macros, M->getConfigurationMacros()); if (!M->getIncludePath().empty()) addString(MDie, dwarf::DW_AT_LLVM_include_path, M->getIncludePath()); if (!M->getAPINotesFile().empty()) addString(MDie, dwarf::DW_AT_LLVM_apinotes, M->getAPINotesFile()); if (M->getFile()) addUInt(MDie, dwarf::DW_AT_decl_file, None, getOrCreateSourceID(M->getFile())); if (M->getLineNo()) addUInt(MDie, dwarf::DW_AT_decl_line, None, M->getLineNo()); return &MDie; } DIE *DwarfUnit::getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal) { // Construct the context before querying for the existence of the DIE in case // such construction creates the DIE (as is the case for member function // declarations). DIE *ContextDIE = Minimal ? &getUnitDie() : getOrCreateContextDIE(SP->getScope()); if (DIE *SPDie = getDIE(SP)) return SPDie; if (auto *SPDecl = SP->getDeclaration()) { if (!Minimal) { // Add subprogram definitions to the CU die directly. ContextDIE = &getUnitDie(); // Build the decl now to ensure it precedes the definition. getOrCreateSubprogramDIE(SPDecl); } } // DW_TAG_inlined_subroutine may refer to this DIE. DIE &SPDie = createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, SP); // Stop here and fill this in later, depending on whether or not this // subprogram turns out to have inlined instances or not. if (SP->isDefinition()) return &SPDie; static_cast(SPDie.getUnit()) ->applySubprogramAttributes(SP, SPDie); return &SPDie; } bool DwarfUnit::applySubprogramDefinitionAttributes(const DISubprogram *SP, DIE &SPDie) { DIE *DeclDie = nullptr; StringRef DeclLinkageName; if (auto *SPDecl = SP->getDeclaration()) { DITypeRefArray DeclArgs, DefinitionArgs; DeclArgs = SPDecl->getType()->getTypeArray(); DefinitionArgs = SP->getType()->getTypeArray(); if (DeclArgs.size() && DefinitionArgs.size()) if (DefinitionArgs[0] != NULL && DeclArgs[0] != DefinitionArgs[0]) addType(SPDie, DefinitionArgs[0]); DeclDie = getDIE(SPDecl); assert(DeclDie && "This DIE should've already been constructed when the " "definition DIE was created in " "getOrCreateSubprogramDIE"); // Look at the Decl's linkage name only if we emitted it. if (DD->useAllLinkageNames()) DeclLinkageName = SPDecl->getLinkageName(); unsigned DeclID = getOrCreateSourceID(SPDecl->getFile()); unsigned DefID = getOrCreateSourceID(SP->getFile()); if (DeclID != DefID) addUInt(SPDie, dwarf::DW_AT_decl_file, None, DefID); if (SP->getLine() != SPDecl->getLine()) addUInt(SPDie, dwarf::DW_AT_decl_line, None, SP->getLine()); } // Add function template parameters. addTemplateParams(SPDie, SP->getTemplateParams()); // Add the linkage name if we have one and it isn't in the Decl. StringRef LinkageName = SP->getLinkageName(); assert(((LinkageName.empty() || DeclLinkageName.empty()) || LinkageName == DeclLinkageName) && "decl has a linkage name and it is different"); if (DeclLinkageName.empty() && // Always emit it for abstract subprograms. (DD->useAllLinkageNames() || DU->getAbstractSPDies().lookup(SP))) addLinkageName(SPDie, LinkageName); if (!DeclDie) return false; // Refer to the function declaration where all the other attributes will be // found. addDIEEntry(SPDie, dwarf::DW_AT_specification, *DeclDie); return true; } void DwarfUnit::applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie, bool SkipSPAttributes) { // If -fdebug-info-for-profiling is enabled, need to emit the subprogram // and its source location. bool SkipSPSourceLocation = SkipSPAttributes && !CUNode->getDebugInfoForProfiling(); if (!SkipSPSourceLocation) if (applySubprogramDefinitionAttributes(SP, SPDie)) return; // Constructors and operators for anonymous aggregates do not have names. if (!SP->getName().empty()) addString(SPDie, dwarf::DW_AT_name, SP->getName()); if (!SkipSPSourceLocation) addSourceLine(SPDie, SP); // Skip the rest of the attributes under -gmlt to save space. if (SkipSPAttributes) return; // Add the prototype if we have a prototype and we have a C like // language. uint16_t Language = getLanguage(); if (SP->isPrototyped() && (Language == dwarf::DW_LANG_C89 || Language == dwarf::DW_LANG_C99 || Language == dwarf::DW_LANG_ObjC)) addFlag(SPDie, dwarf::DW_AT_prototyped); if (SP->isObjCDirect()) addFlag(SPDie, dwarf::DW_AT_APPLE_objc_direct); unsigned CC = 0; DITypeRefArray Args; if (const DISubroutineType *SPTy = SP->getType()) { Args = SPTy->getTypeArray(); CC = SPTy->getCC(); } // Add a DW_AT_calling_convention if this has an explicit convention. if (CC && CC != dwarf::DW_CC_normal) addUInt(SPDie, dwarf::DW_AT_calling_convention, dwarf::DW_FORM_data1, CC); // Add a return type. If this is a type like a C/C++ void type we don't add a // return type. if (Args.size()) if (auto Ty = Args[0]) addType(SPDie, Ty); unsigned VK = SP->getVirtuality(); if (VK) { addUInt(SPDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1, VK); if (SP->getVirtualIndex() != -1u) { DIELoc *Block = getDIELoc(); addUInt(*Block, dwarf::DW_FORM_data1, dwarf::DW_OP_constu); addUInt(*Block, dwarf::DW_FORM_udata, SP->getVirtualIndex()); addBlock(SPDie, dwarf::DW_AT_vtable_elem_location, Block); } ContainingTypeMap.insert(std::make_pair(&SPDie, SP->getContainingType())); } if (!SP->isDefinition()) { addFlag(SPDie, dwarf::DW_AT_declaration); // Add arguments. Do not add arguments for subprogram definition. They will // be handled while processing variables. constructSubprogramArguments(SPDie, Args); } addThrownTypes(SPDie, SP->getThrownTypes()); if (SP->isArtificial()) addFlag(SPDie, dwarf::DW_AT_artificial); if (!SP->isLocalToUnit()) addFlag(SPDie, dwarf::DW_AT_external); if (DD->useAppleExtensionAttributes()) { if (SP->isOptimized()) addFlag(SPDie, dwarf::DW_AT_APPLE_optimized); if (unsigned isa = Asm->getISAEncoding()) addUInt(SPDie, dwarf::DW_AT_APPLE_isa, dwarf::DW_FORM_flag, isa); } if (SP->isLValueReference()) addFlag(SPDie, dwarf::DW_AT_reference); if (SP->isRValueReference()) addFlag(SPDie, dwarf::DW_AT_rvalue_reference); if (SP->isNoReturn()) addFlag(SPDie, dwarf::DW_AT_noreturn); if (SP->isProtected()) addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_protected); else if (SP->isPrivate()) addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_private); else if (SP->isPublic()) addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_public); if (SP->isExplicit()) addFlag(SPDie, dwarf::DW_AT_explicit); if (SP->isMainSubprogram()) addFlag(SPDie, dwarf::DW_AT_main_subprogram); if (SP->isPure()) addFlag(SPDie, dwarf::DW_AT_pure); if (SP->isElemental()) addFlag(SPDie, dwarf::DW_AT_elemental); if (SP->isRecursive()) addFlag(SPDie, dwarf::DW_AT_recursive); if (DD->getDwarfVersion() >= 5 && SP->isDeleted()) addFlag(SPDie, dwarf::DW_AT_deleted); } void DwarfUnit::constructSubrangeDIE(DIE &Buffer, const DISubrange *SR, DIE *IndexTy) { DIE &DW_Subrange = createAndAddDIE(dwarf::DW_TAG_subrange_type, Buffer); addDIEEntry(DW_Subrange, dwarf::DW_AT_type, *IndexTy); // The LowerBound value defines the lower bounds which is typically zero for // C/C++. The Count value is the number of elements. Values are 64 bit. If // Count == -1 then the array is unbounded and we do not emit // DW_AT_lower_bound and DW_AT_count attributes. int64_t DefaultLowerBound = getDefaultLowerBound(); int64_t Count = -1; if (auto *CI = SR->getCount().dyn_cast()) Count = CI->getSExtValue(); auto addBoundTypeEntry = [&](dwarf::Attribute Attr, DISubrange::BoundType Bound) -> void { if (auto *BV = Bound.dyn_cast()) { if (auto *VarDIE = getDIE(BV)) addDIEEntry(DW_Subrange, Attr, *VarDIE); } else if (auto *BE = Bound.dyn_cast()) { DIELoc *Loc = new (DIEValueAllocator) DIELoc; DIEDwarfExpression DwarfExpr(*Asm, getCU(), *Loc); DwarfExpr.setMemoryLocationKind(); DwarfExpr.addExpression(BE); addBlock(DW_Subrange, Attr, DwarfExpr.finalize()); } else if (auto *BI = Bound.dyn_cast()) { if (Attr != dwarf::DW_AT_lower_bound || DefaultLowerBound == -1 || BI->getSExtValue() != DefaultLowerBound) addSInt(DW_Subrange, Attr, dwarf::DW_FORM_sdata, BI->getSExtValue()); } }; addBoundTypeEntry(dwarf::DW_AT_lower_bound, SR->getLowerBound()); if (auto *CV = SR->getCount().dyn_cast()) { if (auto *CountVarDIE = getDIE(CV)) addDIEEntry(DW_Subrange, dwarf::DW_AT_count, *CountVarDIE); } else if (Count != -1) addUInt(DW_Subrange, dwarf::DW_AT_count, None, Count); addBoundTypeEntry(dwarf::DW_AT_upper_bound, SR->getUpperBound()); addBoundTypeEntry(dwarf::DW_AT_byte_stride, SR->getStride()); } DIE *DwarfUnit::getIndexTyDie() { if (IndexTyDie) return IndexTyDie; // Construct an integer type to use for indexes. IndexTyDie = &createAndAddDIE(dwarf::DW_TAG_base_type, getUnitDie()); StringRef Name = "__ARRAY_SIZE_TYPE__"; addString(*IndexTyDie, dwarf::DW_AT_name, Name); addUInt(*IndexTyDie, dwarf::DW_AT_byte_size, None, sizeof(int64_t)); addUInt(*IndexTyDie, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1, dwarf::DW_ATE_unsigned); DD->addAccelType(*CUNode, Name, *IndexTyDie, /*Flags*/ 0); return IndexTyDie; } /// Returns true if the vector's size differs from the sum of sizes of elements /// the user specified. This can occur if the vector has been rounded up to /// fit memory alignment constraints. static bool hasVectorBeenPadded(const DICompositeType *CTy) { assert(CTy && CTy->isVector() && "Composite type is not a vector"); const uint64_t ActualSize = CTy->getSizeInBits(); // Obtain the size of each element in the vector. DIType *BaseTy = CTy->getBaseType(); assert(BaseTy && "Unknown vector element type."); const uint64_t ElementSize = BaseTy->getSizeInBits(); // Locate the number of elements in the vector. const DINodeArray Elements = CTy->getElements(); assert(Elements.size() == 1 && Elements[0]->getTag() == dwarf::DW_TAG_subrange_type && "Invalid vector element array, expected one element of type subrange"); const auto Subrange = cast(Elements[0]); const auto NumVecElements = Subrange->getCount() ? Subrange->getCount().get()->getSExtValue() : 0; // Ensure we found the element count and that the actual size is wide // enough to contain the requested size. assert(ActualSize >= (NumVecElements * ElementSize) && "Invalid vector size"); return ActualSize != (NumVecElements * ElementSize); } void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy) { if (CTy->isVector()) { addFlag(Buffer, dwarf::DW_AT_GNU_vector); if (hasVectorBeenPadded(CTy)) addUInt(Buffer, dwarf::DW_AT_byte_size, None, CTy->getSizeInBits() / CHAR_BIT); } if (DIVariable *Var = CTy->getDataLocation()) { if (auto *VarDIE = getDIE(Var)) addDIEEntry(Buffer, dwarf::DW_AT_data_location, *VarDIE); } else if (DIExpression *Expr = CTy->getDataLocationExp()) { DIELoc *Loc = new (DIEValueAllocator) DIELoc; DIEDwarfExpression DwarfExpr(*Asm, getCU(), *Loc); DwarfExpr.setMemoryLocationKind(); DwarfExpr.addExpression(Expr); addBlock(Buffer, dwarf::DW_AT_data_location, DwarfExpr.finalize()); } // Emit the element type. addType(Buffer, CTy->getBaseType()); // Get an anonymous type for index type. // FIXME: This type should be passed down from the front end // as different languages may have different sizes for indexes. DIE *IdxTy = getIndexTyDie(); // Add subranges to array type. DINodeArray Elements = CTy->getElements(); for (unsigned i = 0, N = Elements.size(); i < N; ++i) { // FIXME: Should this really be such a loose cast? if (auto *Element = dyn_cast_or_null(Elements[i])) if (Element->getTag() == dwarf::DW_TAG_subrange_type) constructSubrangeDIE(Buffer, cast(Element), IdxTy); } } void DwarfUnit::constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy) { const DIType *DTy = CTy->getBaseType(); bool IsUnsigned = DTy && isUnsignedDIType(DD, DTy); if (DTy) { if (DD->getDwarfVersion() >= 3) addType(Buffer, DTy); if (DD->getDwarfVersion() >= 4 && (CTy->getFlags() & DINode::FlagEnumClass)) addFlag(Buffer, dwarf::DW_AT_enum_class); } auto *Context = CTy->getScope(); bool IndexEnumerators = !Context || isa(Context) || isa(Context) || isa(Context) || isa(Context); DINodeArray Elements = CTy->getElements(); // Add enumerators to enumeration type. for (unsigned i = 0, N = Elements.size(); i < N; ++i) { auto *Enum = dyn_cast_or_null(Elements[i]); if (Enum) { DIE &Enumerator = createAndAddDIE(dwarf::DW_TAG_enumerator, Buffer); StringRef Name = Enum->getName(); addString(Enumerator, dwarf::DW_AT_name, Name); addConstantValue(Enumerator, Enum->getValue(), IsUnsigned); if (IndexEnumerators) addGlobalName(Name, Enumerator, Context); } } } void DwarfUnit::constructContainingTypeDIEs() { for (auto CI = ContainingTypeMap.begin(), CE = ContainingTypeMap.end(); CI != CE; ++CI) { DIE &SPDie = *CI->first; const DINode *D = CI->second; if (!D) continue; DIE *NDie = getDIE(D); if (!NDie) continue; addDIEEntry(SPDie, dwarf::DW_AT_containing_type, *NDie); } } DIE &DwarfUnit::constructMemberDIE(DIE &Buffer, const DIDerivedType *DT) { DIE &MemberDie = createAndAddDIE(DT->getTag(), Buffer); StringRef Name = DT->getName(); if (!Name.empty()) addString(MemberDie, dwarf::DW_AT_name, Name); if (DIType *Resolved = DT->getBaseType()) addType(MemberDie, Resolved); addSourceLine(MemberDie, DT); if (DT->getTag() == dwarf::DW_TAG_inheritance && DT->isVirtual()) { // For C++, virtual base classes are not at fixed offset. Use following // expression to extract appropriate offset from vtable. // BaseAddr = ObAddr + *((*ObAddr) - Offset) DIELoc *VBaseLocationDie = new (DIEValueAllocator) DIELoc; addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_dup); addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref); addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_constu); addUInt(*VBaseLocationDie, dwarf::DW_FORM_udata, DT->getOffsetInBits()); addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_minus); addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref); addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus); addBlock(MemberDie, dwarf::DW_AT_data_member_location, VBaseLocationDie); } else { uint64_t Size = DT->getSizeInBits(); uint64_t FieldSize = DD->getBaseTypeSize(DT); uint32_t AlignInBytes = DT->getAlignInBytes(); uint64_t OffsetInBytes; bool IsBitfield = FieldSize && Size != FieldSize; if (IsBitfield) { // Handle bitfield, assume bytes are 8 bits. if (DD->useDWARF2Bitfields()) addUInt(MemberDie, dwarf::DW_AT_byte_size, None, FieldSize/8); addUInt(MemberDie, dwarf::DW_AT_bit_size, None, Size); uint64_t Offset = DT->getOffsetInBits(); // We can't use DT->getAlignInBits() here: AlignInBits for member type // is non-zero if and only if alignment was forced (e.g. _Alignas()), // which can't be done with bitfields. Thus we use FieldSize here. uint32_t AlignInBits = FieldSize; uint32_t AlignMask = ~(AlignInBits - 1); // The bits from the start of the storage unit to the start of the field. uint64_t StartBitOffset = Offset - (Offset & AlignMask); // The byte offset of the field's aligned storage unit inside the struct. OffsetInBytes = (Offset - StartBitOffset) / 8; if (DD->useDWARF2Bitfields()) { uint64_t HiMark = (Offset + FieldSize) & AlignMask; uint64_t FieldOffset = (HiMark - FieldSize); Offset -= FieldOffset; // Maybe we need to work from the other end. if (Asm->getDataLayout().isLittleEndian()) Offset = FieldSize - (Offset + Size); addUInt(MemberDie, dwarf::DW_AT_bit_offset, None, Offset); OffsetInBytes = FieldOffset >> 3; } else { addUInt(MemberDie, dwarf::DW_AT_data_bit_offset, None, Offset); } } else { // This is not a bitfield. OffsetInBytes = DT->getOffsetInBits() / 8; if (AlignInBytes) addUInt(MemberDie, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata, AlignInBytes); } if (DD->getDwarfVersion() <= 2) { DIELoc *MemLocationDie = new (DIEValueAllocator) DIELoc; addUInt(*MemLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst); addUInt(*MemLocationDie, dwarf::DW_FORM_udata, OffsetInBytes); addBlock(MemberDie, dwarf::DW_AT_data_member_location, MemLocationDie); } else if (!IsBitfield || DD->useDWARF2Bitfields()) addUInt(MemberDie, dwarf::DW_AT_data_member_location, None, OffsetInBytes); } if (DT->isProtected()) addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_protected); else if (DT->isPrivate()) addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_private); // Otherwise C++ member and base classes are considered public. else if (DT->isPublic()) addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_public); if (DT->isVirtual()) addUInt(MemberDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1, dwarf::DW_VIRTUALITY_virtual); // Objective-C properties. if (DINode *PNode = DT->getObjCProperty()) if (DIE *PDie = getDIE(PNode)) MemberDie.addValue(DIEValueAllocator, dwarf::DW_AT_APPLE_property, dwarf::DW_FORM_ref4, DIEEntry(*PDie)); if (DT->isArtificial()) addFlag(MemberDie, dwarf::DW_AT_artificial); return MemberDie; } DIE *DwarfUnit::getOrCreateStaticMemberDIE(const DIDerivedType *DT) { if (!DT) return nullptr; // Construct the context before querying for the existence of the DIE in case // such construction creates the DIE. DIE *ContextDIE = getOrCreateContextDIE(DT->getScope()); assert(dwarf::isType(ContextDIE->getTag()) && "Static member should belong to a type."); if (DIE *StaticMemberDIE = getDIE(DT)) return StaticMemberDIE; DIE &StaticMemberDIE = createAndAddDIE(DT->getTag(), *ContextDIE, DT); const DIType *Ty = DT->getBaseType(); addString(StaticMemberDIE, dwarf::DW_AT_name, DT->getName()); addType(StaticMemberDIE, Ty); addSourceLine(StaticMemberDIE, DT); addFlag(StaticMemberDIE, dwarf::DW_AT_external); addFlag(StaticMemberDIE, dwarf::DW_AT_declaration); // FIXME: We could omit private if the parent is a class_type, and // public if the parent is something else. if (DT->isProtected()) addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_protected); else if (DT->isPrivate()) addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_private); else if (DT->isPublic()) addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1, dwarf::DW_ACCESS_public); if (const ConstantInt *CI = dyn_cast_or_null(DT->getConstant())) addConstantValue(StaticMemberDIE, CI, Ty); if (const ConstantFP *CFP = dyn_cast_or_null(DT->getConstant())) addConstantFPValue(StaticMemberDIE, CFP); if (uint32_t AlignInBytes = DT->getAlignInBytes()) addUInt(StaticMemberDIE, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata, AlignInBytes); return &StaticMemberDIE; } void DwarfUnit::emitCommonHeader(bool UseOffsets, dwarf::UnitType UT) { // Emit size of content not including length itself Asm->OutStreamer->AddComment("Length of Unit"); if (!DD->useSectionsAsReferences()) { StringRef Prefix = isDwoUnit() ? "debug_info_dwo_" : "debug_info_"; MCSymbol *BeginLabel = Asm->createTempSymbol(Prefix + "start"); EndLabel = Asm->createTempSymbol(Prefix + "end"); Asm->emitLabelDifference(EndLabel, BeginLabel, 4); Asm->OutStreamer->emitLabel(BeginLabel); } else Asm->emitInt32(getHeaderSize() + getUnitDie().getSize()); Asm->OutStreamer->AddComment("DWARF version number"); unsigned Version = DD->getDwarfVersion(); Asm->emitInt16(Version); // DWARF v5 reorders the address size and adds a unit type. if (Version >= 5) { Asm->OutStreamer->AddComment("DWARF Unit Type"); Asm->emitInt8(UT); Asm->OutStreamer->AddComment("Address Size (in bytes)"); Asm->emitInt8(Asm->MAI->getCodePointerSize()); } // We share one abbreviations table across all units so it's always at the // start of the section. Use a relocatable offset where needed to ensure // linking doesn't invalidate that offset. Asm->OutStreamer->AddComment("Offset Into Abbrev. Section"); const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); if (UseOffsets) Asm->emitInt32(0); else Asm->emitDwarfSymbolReference( TLOF.getDwarfAbbrevSection()->getBeginSymbol(), false); if (Version <= 4) { Asm->OutStreamer->AddComment("Address Size (in bytes)"); Asm->emitInt8(Asm->MAI->getCodePointerSize()); } } void DwarfTypeUnit::emitHeader(bool UseOffsets) { DwarfUnit::emitCommonHeader(UseOffsets, DD->useSplitDwarf() ? dwarf::DW_UT_split_type : dwarf::DW_UT_type); Asm->OutStreamer->AddComment("Type Signature"); Asm->OutStreamer->emitIntValue(TypeSignature, sizeof(TypeSignature)); Asm->OutStreamer->AddComment("Type DIE Offset"); // In a skeleton type unit there is no type DIE so emit a zero offset. Asm->OutStreamer->emitIntValue(Ty ? Ty->getOffset() : 0, sizeof(Ty->getOffset())); } DIE::value_iterator DwarfUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi, const MCSymbol *Lo) { return Die.addValue(DIEValueAllocator, Attribute, DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset : dwarf::DW_FORM_data4, new (DIEValueAllocator) DIEDelta(Hi, Lo)); } DIE::value_iterator DwarfUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Label, const MCSymbol *Sec) { if (Asm->MAI->doesDwarfUseRelocationsAcrossSections()) return addLabel(Die, Attribute, DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset : dwarf::DW_FORM_data4, Label); return addSectionDelta(Die, Attribute, Label, Sec); } bool DwarfTypeUnit::isDwoUnit() const { // Since there are no skeleton type units, all type units are dwo type units // when split DWARF is being used. return DD->useSplitDwarf(); } void DwarfTypeUnit::addGlobalName(StringRef Name, const DIE &Die, const DIScope *Context) { getCU().addGlobalNameForTypeUnit(Name, Context); } void DwarfTypeUnit::addGlobalType(const DIType *Ty, const DIE &Die, const DIScope *Context) { getCU().addGlobalTypeUnitType(Ty, Context); } const MCSymbol *DwarfUnit::getCrossSectionRelativeBaseAddress() const { if (!Asm->MAI->doesDwarfUseRelocationsAcrossSections()) return nullptr; if (isDwoUnit()) return nullptr; return getSection()->getBeginSymbol(); } void DwarfUnit::addStringOffsetsStart() { const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); addSectionLabel(getUnitDie(), dwarf::DW_AT_str_offsets_base, DU->getStringOffsetsStartSym(), TLOF.getDwarfStrOffSection()->getBeginSymbol()); } void DwarfUnit::addRnglistsBase() { assert(DD->getDwarfVersion() >= 5 && "DW_AT_rnglists_base requires DWARF version 5 or later"); const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); addSectionLabel(getUnitDie(), dwarf::DW_AT_rnglists_base, DU->getRnglistsTableBaseSym(), TLOF.getDwarfRnglistsSection()->getBeginSymbol()); } void DwarfTypeUnit::finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) { addFlag(D, dwarf::DW_AT_declaration); StringRef Name = CTy->getName(); if (!Name.empty()) addString(D, dwarf::DW_AT_name, Name); getCU().createTypeDIE(CTy); }