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Diffstat (limited to 'contrib/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp | 1616 |
1 files changed, 1616 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp new file mode 100644 index 0000000..3d3da2a --- /dev/null +++ b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp @@ -0,0 +1,1616 @@ +//===-- llvm/CodeGen/DwarfUnit.cpp - Dwarf Type and Compile Units ---------===// +// +// 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 constructing a dwarf compile unit. +// +//===----------------------------------------------------------------------===// + +#include "DwarfUnit.h" +#include "DwarfAccelTable.h" +#include "DwarfCompileUnit.h" +#include "DwarfDebug.h" +#include "DwarfExpression.h" +#include "llvm/ADT/APFloat.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DIBuilder.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/GlobalVariable.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/Mangler.h" +#include "llvm/MC/MCAsmInfo.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCSection.h" +#include "llvm/MC/MCStreamer.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Target/TargetFrameLowering.h" +#include "llvm/Target/TargetLoweringObjectFile.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetRegisterInfo.h" +#include "llvm/Target/TargetSubtargetInfo.h" + +using namespace llvm; + +#define DEBUG_TYPE "dwarfdebug" + +static cl::opt<bool> +GenerateDwarfTypeUnits("generate-type-units", cl::Hidden, + cl::desc("Generate DWARF4 type units."), + cl::init(false)); + +void DIEDwarfExpression::EmitOp(uint8_t Op, const char* Comment) { + DU.addUInt(DIE, dwarf::DW_FORM_data1, Op); +} +void DIEDwarfExpression::EmitSigned(int Value) { + DU.addSInt(DIE, dwarf::DW_FORM_sdata, Value); +} +void DIEDwarfExpression::EmitUnsigned(unsigned Value) { + DU.addUInt(DIE, dwarf::DW_FORM_udata, Value); +} +bool DIEDwarfExpression::isFrameRegister(unsigned MachineReg) { + return MachineReg == getTRI()->getFrameRegister(*AP.MF); +} + + +/// Unit - Unit constructor. +DwarfUnit::DwarfUnit(unsigned UID, dwarf::Tag UnitTag, DICompileUnit Node, + AsmPrinter *A, DwarfDebug *DW, DwarfFile *DWU) + : UniqueID(UID), CUNode(Node), UnitDie(UnitTag), DebugInfoOffset(0), Asm(A), + DD(DW), DU(DWU), IndexTyDie(nullptr), Section(nullptr) { + assert(UnitTag == dwarf::DW_TAG_compile_unit || + UnitTag == dwarf::DW_TAG_type_unit); + DIEIntegerOne = new (DIEValueAllocator) DIEInteger(1); +} + +DwarfTypeUnit::DwarfTypeUnit(unsigned UID, DwarfCompileUnit &CU, AsmPrinter *A, + DwarfDebug *DW, DwarfFile *DWU, + MCDwarfDwoLineTable *SplitLineTable) + : DwarfUnit(UID, dwarf::DW_TAG_type_unit, CU.getCUNode(), A, DW, DWU), + CU(CU), SplitLineTable(SplitLineTable) { + if (SplitLineTable) + addSectionOffset(UnitDie, dwarf::DW_AT_stmt_list, 0); +} + +/// ~Unit - Destructor for compile unit. +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(); +} + +/// createDIEEntry - Creates a new DIEEntry to be a proxy for a debug +/// information entry. +DIEEntry *DwarfUnit::createDIEEntry(DIE &Entry) { + DIEEntry *Value = new (DIEValueAllocator) DIEEntry(Entry); + return Value; +} + +/// getDefaultLowerBound - Return the default lower bound for an array. If the +/// DWARF version doesn't handle the language, return -1. +int64_t DwarfUnit::getDefaultLowerBound() const { + switch (getLanguage()) { + default: + break; + + case dwarf::DW_LANG_C89: + case dwarf::DW_LANG_C99: + case dwarf::DW_LANG_C: + case dwarf::DW_LANG_C_plus_plus: + case dwarf::DW_LANG_ObjC: + case dwarf::DW_LANG_ObjC_plus_plus: + return 0; + + case dwarf::DW_LANG_Fortran77: + case dwarf::DW_LANG_Fortran90: + case dwarf::DW_LANG_Fortran95: + return 1; + + // The languages below have valid values only if the DWARF version >= 4. + case dwarf::DW_LANG_Java: + case dwarf::DW_LANG_Python: + case dwarf::DW_LANG_UPC: + case dwarf::DW_LANG_D: + if (dwarf::DWARF_VERSION >= 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 (dwarf::DWARF_VERSION >= 4) + return 1; + break; + } + + return -1; +} + +/// Check whether the DIE for this MDNode can be shared across CUs. +static bool isShareableAcrossCUs(DIDescriptor D) { + // When the MDNode can be part of the type system, the DIE can 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. + return (D.isType() || + (D.isSubprogram() && !DISubprogram(D).isDefinition())) && + !GenerateDwarfTypeUnits; +} + +/// getDIE - Returns the debug information entry map slot for the +/// specified debug variable. We delegate the request to DwarfDebug +/// when the DIE for this MDNode can be shared across CUs. The mappings +/// will be kept in DwarfDebug for shareable DIEs. +DIE *DwarfUnit::getDIE(DIDescriptor D) const { + if (isShareableAcrossCUs(D)) + return DU->getDIE(D); + return MDNodeToDieMap.lookup(D); +} + +/// insertDIE - Insert DIE into the map. We delegate the request to DwarfDebug +/// when the DIE for this MDNode can be shared across CUs. The mappings +/// will be kept in DwarfDebug for shareable DIEs. +void DwarfUnit::insertDIE(DIDescriptor Desc, DIE *D) { + if (isShareableAcrossCUs(Desc)) { + DU->insertDIE(Desc, D); + return; + } + MDNodeToDieMap.insert(std::make_pair(Desc, D)); +} + +/// addFlag - Add a flag that is true. +void DwarfUnit::addFlag(DIE &Die, dwarf::Attribute Attribute) { + if (DD->getDwarfVersion() >= 4) + Die.addValue(Attribute, dwarf::DW_FORM_flag_present, DIEIntegerOne); + else + Die.addValue(Attribute, dwarf::DW_FORM_flag, DIEIntegerOne); +} + +/// addUInt - Add an unsigned integer attribute data and value. +/// +void DwarfUnit::addUInt(DIE &Die, dwarf::Attribute Attribute, + Optional<dwarf::Form> Form, uint64_t Integer) { + if (!Form) + Form = DIEInteger::BestForm(false, Integer); + DIEValue *Value = Integer == 1 ? DIEIntegerOne : new (DIEValueAllocator) + DIEInteger(Integer); + Die.addValue(Attribute, *Form, Value); +} + +void DwarfUnit::addUInt(DIE &Block, dwarf::Form Form, uint64_t Integer) { + addUInt(Block, (dwarf::Attribute)0, Form, Integer); +} + +/// addSInt - Add an signed integer attribute data and value. +/// +void DwarfUnit::addSInt(DIE &Die, dwarf::Attribute Attribute, + Optional<dwarf::Form> Form, int64_t Integer) { + if (!Form) + Form = DIEInteger::BestForm(true, Integer); + DIEValue *Value = new (DIEValueAllocator) DIEInteger(Integer); + Die.addValue(Attribute, *Form, Value); +} + +void DwarfUnit::addSInt(DIELoc &Die, Optional<dwarf::Form> Form, + int64_t Integer) { + addSInt(Die, (dwarf::Attribute)0, Form, Integer); +} + +/// addString - Add a string attribute data and value. We always emit a +/// reference to the string pool instead of immediate strings so that DIEs have +/// more predictable sizes. In the case of split dwarf we emit an index +/// into another table which gets us the static offset into the string +/// table. +void DwarfUnit::addString(DIE &Die, dwarf::Attribute Attribute, + StringRef String) { + if (!isDwoUnit()) + return addLocalString(Die, Attribute, String); + + addIndexedString(Die, Attribute, String); +} + +void DwarfUnit::addIndexedString(DIE &Die, dwarf::Attribute Attribute, + StringRef String) { + unsigned idx = DU->getStringPool().getIndex(*Asm, String); + DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx); + DIEValue *Str = new (DIEValueAllocator) DIEString(Value, String); + Die.addValue(Attribute, dwarf::DW_FORM_GNU_str_index, Str); +} + +/// addLocalString - Add a string attribute data and value. This is guaranteed +/// to be in the local string pool instead of indirected. +void DwarfUnit::addLocalString(DIE &Die, dwarf::Attribute Attribute, + StringRef String) { + MCSymbol *Symb = DU->getStringPool().getSymbol(*Asm, String); + DIEValue *Value; + if (Asm->MAI->doesDwarfUseRelocationsAcrossSections()) + Value = new (DIEValueAllocator) DIELabel(Symb); + else + Value = new (DIEValueAllocator) DIEDelta(Symb, DD->getDebugStrSym()); + DIEValue *Str = new (DIEValueAllocator) DIEString(Value, String); + Die.addValue(Attribute, dwarf::DW_FORM_strp, Str); +} + +/// addLabel - Add a Dwarf label attribute data and value. +/// +void DwarfUnit::addLabel(DIE &Die, dwarf::Attribute Attribute, dwarf::Form Form, + const MCSymbol *Label) { + DIEValue *Value = new (DIEValueAllocator) DIELabel(Label); + Die.addValue(Attribute, Form, Value); +} + +void DwarfUnit::addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label) { + addLabel(Die, (dwarf::Attribute)0, Form, Label); +} + +/// addSectionOffset - Add an offset into a section attribute data and value. +/// +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); +} + +unsigned DwarfTypeUnit::getOrCreateSourceID(StringRef FileName, StringRef DirName) { + return SplitLineTable ? SplitLineTable->getFile(DirName, FileName) + : getCU().getOrCreateSourceID(FileName, DirName); +} + +/// addOpAddress - Add a dwarf op address data and value using the +/// form given and an op of either DW_FORM_addr or DW_FORM_GNU_addr_index. +/// +void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) { + if (!DD->useSplitDwarf()) { + addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addr); + addLabel(Die, dwarf::DW_FORM_udata, Sym); + } else { + addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_addr_index); + addUInt(Die, dwarf::DW_FORM_GNU_addr_index, + DD->getAddressPool().getIndex(Sym)); + } +} + +void DwarfUnit::addLabelDelta(DIE &Die, dwarf::Attribute Attribute, + const MCSymbol *Hi, const MCSymbol *Lo) { + DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo); + Die.addValue(Attribute, dwarf::DW_FORM_data4, Value); +} + +/// addDIEEntry - Add a DIE attribute data and value. +/// +void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry) { + addDIEEntry(Die, Attribute, createDIEEntry(Entry)); +} + +void DwarfUnit::addDIETypeSignature(DIE &Die, const DwarfTypeUnit &Type) { + // 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(dwarf::DW_AT_signature, dwarf::DW_FORM_ref_sig8, + new (DIEValueAllocator) DIETypeSignature(Type)); +} + +void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute, + DIEEntry *Entry) { + const DIE *DieCU = Die.getUnitOrNull(); + const DIE *EntryCU = Entry->getEntry().getUnitOrNull(); + if (!DieCU) + // We assume that Die belongs to this CU, if it is not linked to any CU yet. + DieCU = &getUnitDie(); + if (!EntryCU) + EntryCU = &getUnitDie(); + Die.addValue(Attribute, + EntryCU == DieCU ? dwarf::DW_FORM_ref4 : dwarf::DW_FORM_ref_addr, + Entry); +} + +/// Create a DIE with the given Tag, add the DIE to its parent, and +/// call insertDIE if MD is not null. +DIE &DwarfUnit::createAndAddDIE(unsigned Tag, DIE &Parent, DIDescriptor N) { + assert(Tag != dwarf::DW_TAG_auto_variable && + Tag != dwarf::DW_TAG_arg_variable); + Parent.addChild(make_unique<DIE>((dwarf::Tag)Tag)); + DIE &Die = *Parent.getChildren().back(); + if (N) + insertDIE(N, &Die); + return Die; +} + +/// addBlock - Add block data. +/// +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(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(Attribute, Block->BestForm(), Block); +} + +/// addSourceLine - Add location information to specified debug information +/// entry. +void DwarfUnit::addSourceLine(DIE &Die, unsigned Line, StringRef File, + StringRef Directory) { + if (Line == 0) + return; + + unsigned FileID = getOrCreateSourceID(File, Directory); + assert(FileID && "Invalid file id"); + addUInt(Die, dwarf::DW_AT_decl_file, None, FileID); + addUInt(Die, dwarf::DW_AT_decl_line, None, Line); +} + +/// addSourceLine - Add location information to specified debug information +/// entry. +void DwarfUnit::addSourceLine(DIE &Die, DIVariable V) { + assert(V.isVariable()); + + addSourceLine(Die, V.getLineNumber(), V.getContext().getFilename(), + V.getContext().getDirectory()); +} + +/// addSourceLine - Add location information to specified debug information +/// entry. +void DwarfUnit::addSourceLine(DIE &Die, DIGlobalVariable G) { + assert(G.isGlobalVariable()); + + addSourceLine(Die, G.getLineNumber(), G.getFilename(), G.getDirectory()); +} + +/// addSourceLine - Add location information to specified debug information +/// entry. +void DwarfUnit::addSourceLine(DIE &Die, DISubprogram SP) { + assert(SP.isSubprogram()); + + addSourceLine(Die, SP.getLineNumber(), SP.getFilename(), SP.getDirectory()); +} + +/// addSourceLine - Add location information to specified debug information +/// entry. +void DwarfUnit::addSourceLine(DIE &Die, DIType Ty) { + assert(Ty.isType()); + + addSourceLine(Die, Ty.getLineNumber(), Ty.getFilename(), Ty.getDirectory()); +} + +/// addSourceLine - Add location information to specified debug information +/// entry. +void DwarfUnit::addSourceLine(DIE &Die, DIObjCProperty Ty) { + assert(Ty.isObjCProperty()); + + DIFile File = Ty.getFile(); + addSourceLine(Die, Ty.getLineNumber(), File.getFilename(), + File.getDirectory()); +} + +/// addSourceLine - Add location information to specified debug information +/// entry. +void DwarfUnit::addSourceLine(DIE &Die, DINameSpace NS) { + assert(NS.Verify()); + + addSourceLine(Die, NS.getLineNumber(), NS.getFilename(), NS.getDirectory()); +} + +/// addRegisterOp - Add register operand. +bool DwarfUnit::addRegisterOpPiece(DIELoc &TheDie, unsigned Reg, + unsigned SizeInBits, unsigned OffsetInBits) { + DIEDwarfExpression Expr(*Asm, *this, TheDie); + Expr.AddMachineRegPiece(Reg, SizeInBits, OffsetInBits); + return true; +} + +/// addRegisterOffset - Add register offset. +bool DwarfUnit::addRegisterOffset(DIELoc &TheDie, unsigned Reg, + int64_t Offset) { + DIEDwarfExpression Expr(*Asm, *this, TheDie); + return Expr.AddMachineRegIndirect(Reg, Offset); +} + +/* Byref variables, in Blocks, are declared by the programmer as "SomeType + VarName;", but the compiler creates a __Block_byref_x_VarName struct, and + gives the variable VarName either the struct, or a pointer to the struct, as + its type. This is necessary for various behind-the-scenes things the + compiler needs to do with by-reference variables in Blocks. + + However, as far as the original *programmer* is concerned, the variable + should still have type 'SomeType', as originally declared. + + The function getBlockByrefType dives into the __Block_byref_x_VarName + struct to find the original type of the variable, which is then assigned to + the variable's Debug Information Entry as its real type. So far, so good. + However now the debugger will expect the variable VarName to have the type + SomeType. So we need the location attribute for the variable to be an + expression that explains to the debugger how to navigate through the + pointers and struct to find the actual variable of type SomeType. + + The following function does just that. We start by getting + the "normal" location for the variable. This will be the location + of either the struct __Block_byref_x_VarName or the pointer to the + struct __Block_byref_x_VarName. + + The struct will look something like: + + struct __Block_byref_x_VarName { + ... <various fields> + struct __Block_byref_x_VarName *forwarding; + ... <various other fields> + SomeType VarName; + ... <maybe more fields> + }; + + If we are given the struct directly (as our starting point) we + need to tell the debugger to: + + 1). Add the offset of the forwarding field. + + 2). Follow that pointer to get the real __Block_byref_x_VarName + struct to use (the real one may have been copied onto the heap). + + 3). Add the offset for the field VarName, to find the actual variable. + + If we started with a pointer to the struct, then we need to + dereference that pointer first, before the other steps. + Translating this into DWARF ops, we will need to append the following + to the current location description for the variable: + + DW_OP_deref -- optional, if we start with a pointer + DW_OP_plus_uconst <forward_fld_offset> + DW_OP_deref + DW_OP_plus_uconst <varName_fld_offset> + + That is what this function does. */ + +/// addBlockByrefAddress - Start with the address based on the location +/// provided, and generate the DWARF information necessary to find the +/// actual Block variable (navigating the Block struct) based on the +/// starting location. Add the DWARF information to the die. For +/// more information, read large comment just above here. +/// +void DwarfUnit::addBlockByrefAddress(const DbgVariable &DV, DIE &Die, + dwarf::Attribute Attribute, + const MachineLocation &Location) { + DIType Ty = DV.getType(); + DIType TmpTy = Ty; + uint16_t Tag = Ty.getTag(); + bool isPointer = false; + + StringRef varName = DV.getName(); + + if (Tag == dwarf::DW_TAG_pointer_type) { + DIDerivedType DTy(Ty); + TmpTy = resolve(DTy.getTypeDerivedFrom()); + isPointer = true; + } + + DICompositeType blockStruct(TmpTy); + + // Find the __forwarding field and the variable field in the __Block_byref + // struct. + DIArray Fields = blockStruct.getElements(); + DIDerivedType varField; + DIDerivedType forwardingField; + + for (unsigned i = 0, N = Fields.getNumElements(); i < N; ++i) { + DIDerivedType DT(Fields.getElement(i)); + StringRef fieldName = DT.getName(); + if (fieldName == "__forwarding") + forwardingField = DT; + else if (fieldName == varName) + varField = DT; + } + + // Get the offsets for the forwarding field and the variable field. + unsigned forwardingFieldOffset = forwardingField.getOffsetInBits() >> 3; + unsigned varFieldOffset = varField.getOffsetInBits() >> 2; + + // Decode the original location, and use that as the start of the byref + // variable's location. + DIELoc *Loc = new (DIEValueAllocator) DIELoc(); + + bool validReg; + if (Location.isReg()) + validReg = addRegisterOpPiece(*Loc, Location.getReg()); + else + validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset()); + + if (!validReg) + return; + + // If we started with a pointer to the __Block_byref... struct, then + // the first thing we need to do is dereference the pointer (DW_OP_deref). + if (isPointer) + addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref); + + // Next add the offset for the '__forwarding' field: + // DW_OP_plus_uconst ForwardingFieldOffset. Note there's no point in + // adding the offset if it's 0. + if (forwardingFieldOffset > 0) { + addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst); + addUInt(*Loc, dwarf::DW_FORM_udata, forwardingFieldOffset); + } + + // Now dereference the __forwarding field to get to the real __Block_byref + // struct: DW_OP_deref. + addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref); + + // Now that we've got the real __Block_byref... struct, add the offset + // for the variable's field to get to the location of the actual variable: + // DW_OP_plus_uconst varFieldOffset. Again, don't add if it's 0. + if (varFieldOffset > 0) { + addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst); + addUInt(*Loc, dwarf::DW_FORM_udata, varFieldOffset); + } + + // Now attach the location information to the DIE. + addBlock(Die, Attribute, Loc); +} + +/// Return true if type encoding is unsigned. +static bool isUnsignedDIType(DwarfDebug *DD, DIType Ty) { + DIDerivedType DTy(Ty); + if (DTy.isDerivedType()) { + dwarf::Tag T = (dwarf::Tag)Ty.getTag(); + // Encode pointer constants as unsigned bytes. This is used at least for + // null pointer constant emission. + // (Pieces of) aggregate types that get hacked apart by SROA may also be + // represented by a constant. Encode them as unsigned bytes. + // 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_array_type || + T == dwarf::DW_TAG_class_type || + 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 || + T == dwarf::DW_TAG_structure_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_enumeration_type); + if (DITypeRef Deriv = DTy.getTypeDerivedFrom()) + return isUnsignedDIType(DD, DD->resolve(Deriv)); + // FIXME: Enums without a fixed underlying type have unknown signedness + // here, leading to incorrectly emitted constants. + assert(DTy.getTag() == dwarf::DW_TAG_enumeration_type); + return false; + } + + DIBasicType BTy(Ty); + assert(BTy.isBasicType()); + 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_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); +} + +/// If this type is derived from a base type then return base type size. +static uint64_t getBaseTypeSize(DwarfDebug *DD, DIDerivedType Ty) { + unsigned Tag = Ty.getTag(); + + if (Tag != dwarf::DW_TAG_member && Tag != dwarf::DW_TAG_typedef && + Tag != dwarf::DW_TAG_const_type && Tag != dwarf::DW_TAG_volatile_type && + Tag != dwarf::DW_TAG_restrict_type) + return Ty.getSizeInBits(); + + DIType BaseType = DD->resolve(Ty.getTypeDerivedFrom()); + + // If this type is not derived from any type or the type is a declaration then + // take conservative approach. + if (!BaseType.isValid() || BaseType.isForwardDecl()) + return Ty.getSizeInBits(); + + // If this is a derived type, go ahead and get the base type, unless it's a + // reference then it's just the size of the field. Pointer types have no need + // of this since they're a different type of qualification on the type. + if (BaseType.getTag() == dwarf::DW_TAG_reference_type || + BaseType.getTag() == dwarf::DW_TAG_rvalue_reference_type) + return Ty.getSizeInBits(); + + if (BaseType.isDerivedType()) + return getBaseTypeSize(DD, DIDerivedType(BaseType)); + + return BaseType.getSizeInBits(); +} + +/// addConstantFPValue - Add constant value entry in variable DIE. +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); +} + +/// addConstantFPValue - Add constant value entry in variable DIE. +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); +} + +/// addConstantValue - Add constant value entry in variable DIE. +void DwarfUnit::addConstantValue(DIE &Die, const ConstantInt *CI, DIType Ty) { + addConstantValue(Die, CI->getValue(), Ty); +} + +/// addConstantValue - Add constant value entry in variable DIE. +void DwarfUnit::addConstantValue(DIE &Die, const MachineOperand &MO, + DIType Ty) { + assert(MO.isImm() && "Invalid machine operand!"); + + addConstantValue(Die, isUnsignedDIType(DD, Ty), MO.getImm()); +} + +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, DIType Ty) { + addConstantValue(Die, Val, isUnsignedDIType(DD, Ty)); +} + +// addConstantValue - Add constant value entry in variable DIE. +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); +} + +/// addTemplateParams - Add template parameters into buffer. +void DwarfUnit::addTemplateParams(DIE &Buffer, DIArray TParams) { + // Add template parameters. + for (unsigned i = 0, e = TParams.getNumElements(); i != e; ++i) { + DIDescriptor Element = TParams.getElement(i); + if (Element.isTemplateTypeParameter()) + constructTemplateTypeParameterDIE(Buffer, + DITemplateTypeParameter(Element)); + else if (Element.isTemplateValueParameter()) + constructTemplateValueParameterDIE(Buffer, + DITemplateValueParameter(Element)); + } +} + +/// getOrCreateContextDIE - Get context owner's DIE. +DIE *DwarfUnit::getOrCreateContextDIE(DIScope Context) { + if (!Context || Context.isFile()) + return &getUnitDie(); + if (Context.isType()) + return getOrCreateTypeDIE(DIType(Context)); + if (Context.isNameSpace()) + return getOrCreateNameSpace(DINameSpace(Context)); + if (Context.isSubprogram()) + return getOrCreateSubprogramDIE(DISubprogram(Context)); + return getDIE(Context); +} + +DIE *DwarfUnit::createTypeDIE(DICompositeType Ty) { + DIScope Context = resolve(Ty.getContext()); + DIE *ContextDIE = getOrCreateContextDIE(Context); + + if (DIE *TyDIE = getDIE(Ty)) + return TyDIE; + + // Create new type. + DIE &TyDIE = createAndAddDIE(Ty.getTag(), *ContextDIE, Ty); + + constructTypeDIE(TyDIE, Ty); + + updateAcceleratorTables(Context, Ty, TyDIE); + return &TyDIE; +} + +/// getOrCreateTypeDIE - Find existing DIE or create new DIE for the +/// given DIType. +DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) { + if (!TyNode) + return nullptr; + + DIType Ty(TyNode); + assert(Ty.isType()); + assert(Ty == resolve(Ty.getRef()) && + "type was not uniqued, possible ODR violation."); + + // DW_TAG_restrict_type is not supported in DWARF2 + if (Ty.getTag() == dwarf::DW_TAG_restrict_type && DD->getDwarfVersion() <= 2) + return getOrCreateTypeDIE(resolve(DIDerivedType(Ty).getTypeDerivedFrom())); + + // Construct the context before querying for the existence of the DIE in case + // such construction creates the DIE. + DIScope Context = resolve(Ty.getContext()); + DIE *ContextDIE = getOrCreateContextDIE(Context); + assert(ContextDIE); + + if (DIE *TyDIE = getDIE(Ty)) + return TyDIE; + + // Create new type. + DIE &TyDIE = createAndAddDIE(Ty.getTag(), *ContextDIE, Ty); + + updateAcceleratorTables(Context, Ty, TyDIE); + + if (Ty.isBasicType()) + constructTypeDIE(TyDIE, DIBasicType(Ty)); + else if (Ty.isCompositeType()) { + DICompositeType CTy(Ty); + if (GenerateDwarfTypeUnits && !Ty.isForwardDecl()) + if (MDString *TypeId = CTy.getIdentifier()) { + DD->addDwarfTypeUnitType(getCU(), TypeId->getString(), TyDIE, CTy); + // Skip updating the accelerator tables since this is not the full type. + return &TyDIE; + } + constructTypeDIE(TyDIE, CTy); + } else { + assert(Ty.isDerivedType() && "Unknown kind of DIType"); + constructTypeDIE(TyDIE, DIDerivedType(Ty)); + } + + return &TyDIE; +} + +void DwarfUnit::updateAcceleratorTables(DIScope Context, DIType Ty, + const DIE &TyDIE) { + if (!Ty.getName().empty() && !Ty.isForwardDecl()) { + bool IsImplementation = 0; + if (Ty.isCompositeType()) { + DICompositeType CT(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(Ty.getName(), TyDIE, Flags); + + if (!Context || Context.isCompileUnit() || Context.isFile() || + Context.isNameSpace()) + addGlobalType(Ty, TyDIE, Context); + } +} + +/// addType - Add a new type attribute to the specified entity. +void DwarfUnit::addType(DIE &Entity, DIType Ty, dwarf::Attribute Attribute) { + assert(Ty && "Trying to add a type that doesn't exist?"); + + // Check for pre-existence. + DIEEntry *Entry = getDIEEntry(Ty); + // If it exists then use the existing value. + if (Entry) { + addDIEEntry(Entity, Attribute, Entry); + return; + } + + // Construct type. + DIE *Buffer = getOrCreateTypeDIE(Ty); + + // Set up proxy. + Entry = createDIEEntry(*Buffer); + insertDIEEntry(Ty, Entry); + addDIEEntry(Entity, Attribute, Entry); +} + +/// getParentContextString - Walks the metadata parent chain in a language +/// specific manner (using the compile unit language) and returns +/// it as a string. This is done at the metadata level because DIEs may +/// not currently have been added to the parent context and walking the +/// DIEs looking for names is more expensive than walking the metadata. +std::string DwarfUnit::getParentContextString(DIScope Context) const { + if (!Context) + return ""; + + // FIXME: Decide whether to implement this for non-C++ languages. + if (getLanguage() != dwarf::DW_LANG_C_plus_plus) + return ""; + + std::string CS; + SmallVector<DIScope, 1> Parents; + while (!Context.isCompileUnit()) { + Parents.push_back(Context); + if (Context.getContext()) + Context = resolve(Context.getContext()); + 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 (SmallVectorImpl<DIScope>::reverse_iterator I = Parents.rbegin(), + E = Parents.rend(); + I != E; ++I) { + DIScope Ctx = *I; + StringRef Name = Ctx.getName(); + if (Name.empty() && Ctx.isNameSpace()) + Name = "(anonymous namespace)"; + if (!Name.empty()) { + CS += Name; + CS += "::"; + } + } + return CS; +} + +/// constructTypeDIE - Construct basic type die from DIBasicType. +void DwarfUnit::constructTypeDIE(DIE &Buffer, 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); +} + +/// constructTypeDIE - Construct derived type die from DIDerivedType. +void DwarfUnit::constructTypeDIE(DIE &Buffer, 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. + DIType FromTy = resolve(DTy.getTypeDerivedFrom()); + if (FromTy) + addType(Buffer, FromTy); + + // Add name if not anonymous or intermediate type. + if (!Name.empty()) + addString(Buffer, dwarf::DW_AT_name, Name); + + // 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) + 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(resolve(DTy.getClassType()))); + // Add source line info if available and TyDesc is not a forward declaration. + if (!DTy.isForwardDecl()) + addSourceLine(Buffer, DTy); +} + +/// constructSubprogramArguments - Construct function argument DIEs. +void DwarfUnit::constructSubprogramArguments(DIE &Buffer, DITypeArray Args) { + for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) { + DIType Ty = resolve(Args.getElement(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); + } + } +} + +/// constructTypeDIE - Construct type DIE from DICompositeType. +void DwarfUnit::constructTypeDIE(DIE &Buffer, 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_subroutine_type: { + // Add return type. A void return won't have a type. + DITypeArray Elements = DISubroutineType(CTy).getTypeArray(); + DIType RTy(resolve(Elements.getElement(0))); + if (RTy) + addType(Buffer, RTy); + + bool isPrototyped = true; + if (Elements.getNumElements() == 2 && + !Elements.getElement(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); + + if (CTy.isLValueReference()) + addFlag(Buffer, dwarf::DW_AT_reference); + + if (CTy.isRValueReference()) + addFlag(Buffer, dwarf::DW_AT_rvalue_reference); + } break; + case dwarf::DW_TAG_structure_type: + case dwarf::DW_TAG_union_type: + case dwarf::DW_TAG_class_type: { + // Add elements to structure type. + DIArray Elements = CTy.getElements(); + for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) { + DIDescriptor Element = Elements.getElement(i); + if (Element.isSubprogram()) + getOrCreateSubprogramDIE(DISubprogram(Element)); + else if (Element.isDerivedType()) { + DIDerivedType DDTy(Element); + if (DDTy.getTag() == dwarf::DW_TAG_friend) { + DIE &ElemDie = createAndAddDIE(dwarf::DW_TAG_friend, Buffer); + addType(ElemDie, resolve(DDTy.getTypeDerivedFrom()), + dwarf::DW_AT_friend); + } else if (DDTy.isStaticMember()) { + getOrCreateStaticMemberDIE(DDTy); + } else { + constructMemberDIE(Buffer, DDTy); + } + } else if (Element.isObjCProperty()) { + DIObjCProperty Property(Element); + DIE &ElemDie = createAndAddDIE(Property.getTag(), Buffer); + StringRef PropertyName = Property.getObjCPropertyName(); + addString(ElemDie, dwarf::DW_AT_APPLE_property_name, PropertyName); + if (Property.getType()) + addType(ElemDie, Property.getType()); + addSourceLine(ElemDie, Property); + StringRef GetterName = Property.getObjCPropertyGetterName(); + if (!GetterName.empty()) + addString(ElemDie, dwarf::DW_AT_APPLE_property_getter, GetterName); + StringRef SetterName = Property.getObjCPropertySetterName(); + if (!SetterName.empty()) + addString(ElemDie, dwarf::DW_AT_APPLE_property_setter, SetterName); + unsigned PropertyAttributes = 0; + if (Property.isReadOnlyObjCProperty()) + PropertyAttributes |= dwarf::DW_APPLE_PROPERTY_readonly; + if (Property.isReadWriteObjCProperty()) + PropertyAttributes |= dwarf::DW_APPLE_PROPERTY_readwrite; + if (Property.isAssignObjCProperty()) + PropertyAttributes |= dwarf::DW_APPLE_PROPERTY_assign; + if (Property.isRetainObjCProperty()) + PropertyAttributes |= dwarf::DW_APPLE_PROPERTY_retain; + if (Property.isCopyObjCProperty()) + PropertyAttributes |= dwarf::DW_APPLE_PROPERTY_copy; + if (Property.isNonAtomicObjCProperty()) + PropertyAttributes |= dwarf::DW_APPLE_PROPERTY_nonatomic; + if (PropertyAttributes) + addUInt(ElemDie, dwarf::DW_AT_APPLE_property_attribute, None, + PropertyAttributes); + + DIEEntry *Entry = getDIEEntry(Element); + if (!Entry) { + Entry = createDIEEntry(ElemDie); + insertDIEEntry(Element, Entry); + } + } else + continue; + } + + if (CTy.isAppleBlockExtension()) + addFlag(Buffer, dwarf::DW_AT_APPLE_block); + + // 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. + DICompositeType ContainingType(resolve(CTy.getContainingType())); + if (ContainingType) + 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()); + + 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); + } +} + +/// constructTemplateTypeParameterDIE - Construct new DIE for the given +/// DITemplateTypeParameter. +void DwarfUnit::constructTemplateTypeParameterDIE(DIE &Buffer, + 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, resolve(TP.getType())); + if (!TP.getName().empty()) + addString(ParamDIE, dwarf::DW_AT_name, TP.getName()); +} + +/// constructTemplateValueParameterDIE - Construct new DIE for the given +/// DITemplateValueParameter. +void +DwarfUnit::constructTemplateValueParameterDIE(DIE &Buffer, + 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, resolve(VP.getType())); + if (!VP.getName().empty()) + addString(ParamDIE, dwarf::DW_AT_name, VP.getName()); + if (Metadata *Val = VP.getValue()) { + if (ConstantInt *CI = mdconst::dyn_extract<ConstantInt>(Val)) + addConstantValue(ParamDIE, CI, resolve(VP.getType())); + else if (GlobalValue *GV = mdconst::dyn_extract<GlobalValue>(Val)) { + // 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<MDString>(Val)); + addString(ParamDIE, dwarf::DW_AT_GNU_template_name, + cast<MDString>(Val)->getString()); + } else if (VP.getTag() == dwarf::DW_TAG_GNU_template_parameter_pack) { + assert(isa<MDNode>(Val)); + DIArray A(cast<MDNode>(Val)); + addTemplateParams(ParamDIE, A); + } + } +} + +/// getOrCreateNameSpace - Create a DIE for DINameSpace. +DIE *DwarfUnit::getOrCreateNameSpace(DINameSpace NS) { + // Construct the context before querying for the existence of the DIE in case + // such construction creates the DIE. + DIE *ContextDIE = getOrCreateContextDIE(NS.getContext()); + + 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(Name, NDie); + addGlobalName(Name, NDie, NS.getContext()); + addSourceLine(NDie, NS); + return &NDie; +} + +/// getOrCreateSubprogramDIE - Create new DIE using SP. +DIE *DwarfUnit::getOrCreateSubprogramDIE(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(resolve(SP.getContext())); + + if (DIE *SPDie = getDIE(SP)) + return SPDie; + + if (DISubprogram SPDecl = SP.getFunctionDeclaration()) { + 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; + + applySubprogramAttributes(SP, SPDie); + return &SPDie; +} + +bool DwarfUnit::applySubprogramDefinitionAttributes(DISubprogram SP, + DIE &SPDie) { + DIE *DeclDie = nullptr; + StringRef DeclLinkageName; + if (DISubprogram SPDecl = SP.getFunctionDeclaration()) { + DeclDie = getDIE(SPDecl); + assert(DeclDie && "This DIE should've already been constructed when the " + "definition DIE was created in " + "getOrCreateSubprogramDIE"); + DeclLinkageName = SPDecl.getLinkageName(); + } + + // 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 (!LinkageName.empty() && DeclLinkageName.empty()) + addString(SPDie, dwarf::DW_AT_MIPS_linkage_name, + GlobalValue::getRealLinkageName(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(DISubprogram SP, DIE &SPDie, + bool Minimal) { + if (!Minimal) + 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()); + + // Skip the rest of the attributes under -gmlt to save space. + if (Minimal) + return; + + addSourceLine(SPDie, SP); + + // 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); + + DISubroutineType SPTy = SP.getType(); + assert(SPTy.getTag() == dwarf::DW_TAG_subroutine_type && + "the type of a subprogram should be a subroutine"); + + DITypeArray Args = SPTy.getTypeArray(); + // Add a return type. If this is a type like a C/C++ void type we don't add a + // return type. + if (resolve(Args.getElement(0))) + addType(SPDie, DIType(resolve(Args.getElement(0)))); + + unsigned VK = SP.getVirtuality(); + if (VK) { + addUInt(SPDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1, VK); + 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, resolve(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); + } + + if (SP.isArtificial()) + addFlag(SPDie, dwarf::DW_AT_artificial); + + if (!SP.isLocalToUnit()) + addFlag(SPDie, dwarf::DW_AT_external); + + 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.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); +} + +/// constructSubrangeDIE - Construct subrange DIE from DISubrange. +void DwarfUnit::constructSubrangeDIE(DIE &Buffer, 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 LowerBound = SR.getLo(); + int64_t DefaultLowerBound = getDefaultLowerBound(); + int64_t Count = SR.getCount(); + + if (DefaultLowerBound == -1 || LowerBound != DefaultLowerBound) + addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, None, LowerBound); + + if (Count != -1) + // FIXME: An unbounded array should reference the expression that defines + // the array. + addUInt(DW_Subrange, dwarf::DW_AT_count, None, Count); +} + +DIE *DwarfUnit::getIndexTyDie() { + if (IndexTyDie) + return IndexTyDie; + // Construct an integer type to use for indexes. + IndexTyDie = &createAndAddDIE(dwarf::DW_TAG_base_type, UnitDie); + addString(*IndexTyDie, dwarf::DW_AT_name, "sizetype"); + 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); + return IndexTyDie; +} + +/// constructArrayTypeDIE - Construct array type DIE from DICompositeType. +void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, DICompositeType CTy) { + if (CTy.isVector()) + addFlag(Buffer, dwarf::DW_AT_GNU_vector); + + // Emit the element type. + addType(Buffer, resolve(CTy.getTypeDerivedFrom())); + + // 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. + DIArray Elements = CTy.getElements(); + for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) { + DIDescriptor Element = Elements.getElement(i); + if (Element.getTag() == dwarf::DW_TAG_subrange_type) + constructSubrangeDIE(Buffer, DISubrange(Element), IdxTy); + } +} + +/// constructEnumTypeDIE - Construct an enum type DIE from DICompositeType. +void DwarfUnit::constructEnumTypeDIE(DIE &Buffer, DICompositeType CTy) { + DIArray Elements = CTy.getElements(); + + // Add enumerators to enumeration type. + for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) { + DIEnumerator Enum(Elements.getElement(i)); + if (Enum.isEnumerator()) { + DIE &Enumerator = createAndAddDIE(dwarf::DW_TAG_enumerator, Buffer); + StringRef Name = Enum.getName(); + addString(Enumerator, dwarf::DW_AT_name, Name); + int64_t Value = Enum.getEnumValue(); + addSInt(Enumerator, dwarf::DW_AT_const_value, dwarf::DW_FORM_sdata, + Value); + } + } + DIType DTy = resolve(CTy.getTypeDerivedFrom()); + if (DTy) { + addType(Buffer, DTy); + addFlag(Buffer, dwarf::DW_AT_enum_class); + } +} + +/// constructContainingTypeDIEs - Construct DIEs for types that contain +/// vtables. +void DwarfUnit::constructContainingTypeDIEs() { + for (DenseMap<DIE *, const MDNode *>::iterator CI = ContainingTypeMap.begin(), + CE = ContainingTypeMap.end(); + CI != CE; ++CI) { + DIE &SPDie = *CI->first; + DIDescriptor D(CI->second); + if (!D) + continue; + DIE *NDie = getDIE(D); + if (!NDie) + continue; + addDIEEntry(SPDie, dwarf::DW_AT_containing_type, *NDie); + } +} + +/// constructMemberDIE - Construct member DIE from DIDerivedType. +void DwarfUnit::constructMemberDIE(DIE &Buffer, DIDerivedType DT) { + DIE &MemberDie = createAndAddDIE(DT.getTag(), Buffer); + StringRef Name = DT.getName(); + if (!Name.empty()) + addString(MemberDie, dwarf::DW_AT_name, Name); + + addType(MemberDie, resolve(DT.getTypeDerivedFrom())); + + 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 = getBaseTypeSize(DD, DT); + uint64_t OffsetInBytes; + + if (Size != FieldSize) { + // Handle bitfield, assume bytes are 8 bits. + addUInt(MemberDie, dwarf::DW_AT_byte_size, None, FieldSize/8); + addUInt(MemberDie, dwarf::DW_AT_bit_size, None, Size); + + uint64_t Offset = DT.getOffsetInBits(); + uint64_t AlignMask = ~(DT.getAlignInBits() - 1); + 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); + + // Here DW_AT_data_member_location points to the anonymous + // field that includes this bit field. + OffsetInBytes = FieldOffset >> 3; + } else + // This is not a bitfield. + OffsetInBytes = DT.getOffsetInBits() >> 3; + + 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 + 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 (MDNode *PNode = DT.getObjCProperty()) + if (DIEEntry *PropertyDie = getDIEEntry(PNode)) + MemberDie.addValue(dwarf::DW_AT_APPLE_property, dwarf::DW_FORM_ref4, + PropertyDie); + + if (DT.isArtificial()) + addFlag(MemberDie, dwarf::DW_AT_artificial); +} + +/// getOrCreateStaticMemberDIE - Create new DIE for C++ static member. +DIE *DwarfUnit::getOrCreateStaticMemberDIE(DIDerivedType DT) { + if (!DT.Verify()) + return nullptr; + + // Construct the context before querying for the existence of the DIE in case + // such construction creates the DIE. + DIE *ContextDIE = getOrCreateContextDIE(resolve(DT.getContext())); + 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); + + DIType Ty = resolve(DT.getTypeDerivedFrom()); + + 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<ConstantInt>(DT.getConstant())) + addConstantValue(StaticMemberDIE, CI, Ty); + if (const ConstantFP *CFP = dyn_cast_or_null<ConstantFP>(DT.getConstant())) + addConstantFPValue(StaticMemberDIE, CFP); + + return &StaticMemberDIE; +} + +void DwarfUnit::emitHeader(const MCSymbol *ASectionSym) const { + // Emit size of content not including length itself + Asm->OutStreamer.AddComment("Length of Unit"); + Asm->EmitInt32(getHeaderSize() + UnitDie.getSize()); + + Asm->OutStreamer.AddComment("DWARF version number"); + Asm->EmitInt16(DD->getDwarfVersion()); + Asm->OutStreamer.AddComment("Offset Into Abbrev. Section"); + // 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. + if (ASectionSym) + Asm->EmitSectionOffset(ASectionSym, ASectionSym); + else + // Use a constant value when no symbol is provided. + Asm->EmitInt32(0); + Asm->OutStreamer.AddComment("Address Size (in bytes)"); + Asm->EmitInt8(Asm->getDataLayout().getPointerSize()); +} + +void DwarfUnit::initSection(const MCSection *Section) { + assert(!this->Section); + this->Section = Section; +} + +void DwarfTypeUnit::emitHeader(const MCSymbol *ASectionSym) const { + DwarfUnit::emitHeader(ASectionSym); + 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())); +} + +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(); +} |
