//===-- DWARFDebugInfoEntry.cpp -------------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "DWARFDebugInfoEntry.h" #include "DWARFCompileUnit.h" #include "DWARFContext.h" #include "DWARFDebugAbbrev.h" #include "llvm/DebugInfo/DWARFFormValue.h" #include "llvm/Support/DataTypes.h" #include "llvm/Support/Debug.h" #include "llvm/Support/Dwarf.h" #include "llvm/Support/Format.h" #include "llvm/Support/raw_ostream.h" using namespace llvm; using namespace dwarf; // Small helper to extract a DIE pointed by a reference // attribute. It looks up the Unit containing the DIE and calls // DIE.extractFast with the right unit. Returns new unit on success, // nullptr otherwise. static const DWARFUnit *findUnitAndExtractFast(DWARFDebugInfoEntryMinimal &DIE, const DWARFUnit *Unit, uint32_t *Offset) { Unit = Unit->getUnitSection().getUnitForOffset(*Offset); return (Unit && DIE.extractFast(Unit, Offset)) ? Unit : nullptr; } void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS, DWARFUnit *u, unsigned recurseDepth, unsigned indent) const { DataExtractor debug_info_data = u->getDebugInfoExtractor(); uint32_t offset = Offset; if (debug_info_data.isValidOffset(offset)) { uint32_t abbrCode = debug_info_data.getULEB128(&offset); OS << format("\n0x%8.8x: ", Offset); if (abbrCode) { if (AbbrevDecl) { const char *tagString = TagString(getTag()); if (tagString) OS.indent(indent) << tagString; else OS.indent(indent) << format("DW_TAG_Unknown_%x", getTag()); OS << format(" [%u] %c\n", abbrCode, AbbrevDecl->hasChildren() ? '*' : ' '); // Dump all data in the DIE for the attributes. for (const auto &AttrSpec : AbbrevDecl->attributes()) { dumpAttribute(OS, u, &offset, AttrSpec.Attr, AttrSpec.Form, indent); } const DWARFDebugInfoEntryMinimal *child = getFirstChild(); if (recurseDepth > 0 && child) { while (child) { child->dump(OS, u, recurseDepth-1, indent+2); child = child->getSibling(); } } } else { OS << "Abbreviation code not found in 'debug_abbrev' class for code: " << abbrCode << '\n'; } } else { OS.indent(indent) << "NULL\n"; } } } static void dumpApplePropertyAttribute(raw_ostream &OS, uint64_t Val) { OS << " ("; do { uint64_t Bit = 1ULL << countTrailingZeros(Val); if (const char *PropName = ApplePropertyString(Bit)) OS << PropName; else OS << format("DW_APPLE_PROPERTY_0x%" PRIx64, Bit); if (!(Val ^= Bit)) break; OS << ", "; } while (true); OS << ")"; } void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS, DWARFUnit *u, uint32_t *offset_ptr, uint16_t attr, uint16_t form, unsigned indent) const { OS << " "; OS.indent(indent+2); const char *attrString = AttributeString(attr); if (attrString) OS << attrString; else OS << format("DW_AT_Unknown_%x", attr); const char *formString = FormEncodingString(form); if (formString) OS << " [" << formString << ']'; else OS << format(" [DW_FORM_Unknown_%x]", form); DWARFFormValue formValue(form); if (!formValue.extractValue(u->getDebugInfoExtractor(), offset_ptr, u)) return; OS << "\t("; const char *Name = nullptr; std::string File; if (attr == DW_AT_decl_file || attr == DW_AT_call_file) { if (const auto *LT = u->getContext().getLineTableForUnit(u)) if (LT->getFileNameByIndex( formValue.getAsUnsignedConstant().getValue(), u->getCompilationDir(), DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, File)) { File = '"' + File + '"'; Name = File.c_str(); } } else if (Optional Val = formValue.getAsUnsignedConstant()) Name = AttributeValueString(attr, *Val); if (Name) { OS << Name; } else if (attr == DW_AT_decl_line || attr == DW_AT_call_line) { OS << *formValue.getAsUnsignedConstant(); } else { formValue.dump(OS, u); } // We have dumped the attribute raw value. For some attributes // having both the raw value and the pretty-printed value is // interesting. These attributes are handled below. if ((attr == DW_AT_specification || attr == DW_AT_abstract_origin) && // The signature references aren't handled. formValue.getForm() != DW_FORM_ref_sig8) { uint32_t Ref = formValue.getAsReference(u).getValue(); DWARFDebugInfoEntryMinimal DIE; if (const DWARFUnit *RefU = findUnitAndExtractFast(DIE, u, &Ref)) if (const char *Ref = DIE.getName(RefU, DINameKind::LinkageName)) OS << " \"" << Ref << '\"'; } else if (attr == DW_AT_APPLE_property_attribute) { if (Optional OptVal = formValue.getAsUnsignedConstant()) dumpApplePropertyAttribute(OS, *OptVal); } OS << ")\n"; } bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFUnit *U, uint32_t *OffsetPtr) { Offset = *OffsetPtr; DataExtractor DebugInfoData = U->getDebugInfoExtractor(); uint32_t UEndOffset = U->getNextUnitOffset(); if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset)) return false; uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr); if (0 == AbbrCode) { // NULL debug tag entry. AbbrevDecl = nullptr; return true; } AbbrevDecl = U->getAbbreviations()->getAbbreviationDeclaration(AbbrCode); if (nullptr == AbbrevDecl) { // Restore the original offset. *OffsetPtr = Offset; return false; } ArrayRef FixedFormSizes = DWARFFormValue::getFixedFormSizes( U->getAddressByteSize(), U->getVersion()); assert(FixedFormSizes.size() > 0); // Skip all data in the .debug_info for the attributes for (const auto &AttrSpec : AbbrevDecl->attributes()) { uint16_t Form = AttrSpec.Form; uint8_t FixedFormSize = (Form < FixedFormSizes.size()) ? FixedFormSizes[Form] : 0; if (FixedFormSize) *OffsetPtr += FixedFormSize; else if (!DWARFFormValue::skipValue(Form, DebugInfoData, OffsetPtr, U)) { // Restore the original offset. *OffsetPtr = Offset; return false; } } return true; } bool DWARFDebugInfoEntryMinimal::isSubprogramDIE() const { return getTag() == DW_TAG_subprogram; } bool DWARFDebugInfoEntryMinimal::isSubroutineDIE() const { uint32_t Tag = getTag(); return Tag == DW_TAG_subprogram || Tag == DW_TAG_inlined_subroutine; } bool DWARFDebugInfoEntryMinimal::getAttributeValue( const DWARFUnit *U, const uint16_t Attr, DWARFFormValue &FormValue) const { if (!AbbrevDecl) return false; uint32_t AttrIdx = AbbrevDecl->findAttributeIndex(Attr); if (AttrIdx == -1U) return false; DataExtractor DebugInfoData = U->getDebugInfoExtractor(); uint32_t DebugInfoOffset = getOffset(); // Skip the abbreviation code so we are at the data for the attributes DebugInfoData.getULEB128(&DebugInfoOffset); // Skip preceding attribute values. for (uint32_t i = 0; i < AttrIdx; ++i) { DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(i), DebugInfoData, &DebugInfoOffset, U); } FormValue = DWARFFormValue(AbbrevDecl->getFormByIndex(AttrIdx)); return FormValue.extractValue(DebugInfoData, &DebugInfoOffset, U); } const char *DWARFDebugInfoEntryMinimal::getAttributeValueAsString( const DWARFUnit *U, const uint16_t Attr, const char *FailValue) const { DWARFFormValue FormValue; if (!getAttributeValue(U, Attr, FormValue)) return FailValue; Optional Result = FormValue.getAsCString(U); return Result.hasValue() ? Result.getValue() : FailValue; } uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsAddress( const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const { DWARFFormValue FormValue; if (!getAttributeValue(U, Attr, FormValue)) return FailValue; Optional Result = FormValue.getAsAddress(U); return Result.hasValue() ? Result.getValue() : FailValue; } uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsignedConstant( const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const { DWARFFormValue FormValue; if (!getAttributeValue(U, Attr, FormValue)) return FailValue; Optional Result = FormValue.getAsUnsignedConstant(); return Result.hasValue() ? Result.getValue() : FailValue; } uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsReference( const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const { DWARFFormValue FormValue; if (!getAttributeValue(U, Attr, FormValue)) return FailValue; Optional Result = FormValue.getAsReference(U); return Result.hasValue() ? Result.getValue() : FailValue; } uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsSectionOffset( const DWARFUnit *U, const uint16_t Attr, uint64_t FailValue) const { DWARFFormValue FormValue; if (!getAttributeValue(U, Attr, FormValue)) return FailValue; Optional Result = FormValue.getAsSectionOffset(); return Result.hasValue() ? Result.getValue() : FailValue; } uint64_t DWARFDebugInfoEntryMinimal::getRangesBaseAttribute(const DWARFUnit *U, uint64_t FailValue) const { uint64_t Result = getAttributeValueAsSectionOffset(U, DW_AT_ranges_base, -1ULL); if (Result != -1ULL) return Result; return getAttributeValueAsSectionOffset(U, DW_AT_GNU_ranges_base, FailValue); } bool DWARFDebugInfoEntryMinimal::getLowAndHighPC(const DWARFUnit *U, uint64_t &LowPC, uint64_t &HighPC) const { LowPC = getAttributeValueAsAddress(U, DW_AT_low_pc, -1ULL); if (LowPC == -1ULL) return false; HighPC = getAttributeValueAsAddress(U, DW_AT_high_pc, -1ULL); if (HighPC == -1ULL) { // Since DWARF4, DW_AT_high_pc may also be of class constant, in which case // it represents function size. HighPC = getAttributeValueAsUnsignedConstant(U, DW_AT_high_pc, -1ULL); if (HighPC != -1ULL) HighPC += LowPC; } return (HighPC != -1ULL); } DWARFAddressRangesVector DWARFDebugInfoEntryMinimal::getAddressRanges(const DWARFUnit *U) const { if (isNULL()) return DWARFAddressRangesVector(); // Single range specified by low/high PC. uint64_t LowPC, HighPC; if (getLowAndHighPC(U, LowPC, HighPC)) { return DWARFAddressRangesVector(1, std::make_pair(LowPC, HighPC)); } // Multiple ranges from .debug_ranges section. uint32_t RangesOffset = getAttributeValueAsSectionOffset(U, DW_AT_ranges, -1U); if (RangesOffset != -1U) { DWARFDebugRangeList RangeList; if (U->extractRangeList(RangesOffset, RangeList)) return RangeList.getAbsoluteRanges(U->getBaseAddress()); } return DWARFAddressRangesVector(); } void DWARFDebugInfoEntryMinimal::collectChildrenAddressRanges( const DWARFUnit *U, DWARFAddressRangesVector& Ranges) const { if (isNULL()) return; if (isSubprogramDIE()) { const auto &DIERanges = getAddressRanges(U); Ranges.insert(Ranges.end(), DIERanges.begin(), DIERanges.end()); } const DWARFDebugInfoEntryMinimal *Child = getFirstChild(); while (Child) { Child->collectChildrenAddressRanges(U, Ranges); Child = Child->getSibling(); } } bool DWARFDebugInfoEntryMinimal::addressRangeContainsAddress( const DWARFUnit *U, const uint64_t Address) const { for (const auto& R : getAddressRanges(U)) { if (R.first <= Address && Address < R.second) return true; } return false; } const char * DWARFDebugInfoEntryMinimal::getSubroutineName(const DWARFUnit *U, DINameKind Kind) const { if (!isSubroutineDIE()) return nullptr; return getName(U, Kind); } const char * DWARFDebugInfoEntryMinimal::getName(const DWARFUnit *U, DINameKind Kind) const { if (Kind == DINameKind::None) return nullptr; // Try to get mangled name only if it was asked for. if (Kind == DINameKind::LinkageName) { if (const char *name = getAttributeValueAsString(U, DW_AT_MIPS_linkage_name, nullptr)) return name; if (const char *name = getAttributeValueAsString(U, DW_AT_linkage_name, nullptr)) return name; } if (const char *name = getAttributeValueAsString(U, DW_AT_name, nullptr)) return name; // Try to get name from specification DIE. uint32_t spec_ref = getAttributeValueAsReference(U, DW_AT_specification, -1U); if (spec_ref != -1U) { DWARFDebugInfoEntryMinimal spec_die; if (const DWARFUnit *RefU = findUnitAndExtractFast(spec_die, U, &spec_ref)) { if (const char *name = spec_die.getName(RefU, Kind)) return name; } } // Try to get name from abstract origin DIE. uint32_t abs_origin_ref = getAttributeValueAsReference(U, DW_AT_abstract_origin, -1U); if (abs_origin_ref != -1U) { DWARFDebugInfoEntryMinimal abs_origin_die; if (const DWARFUnit *RefU = findUnitAndExtractFast(abs_origin_die, U, &abs_origin_ref)) { if (const char *name = abs_origin_die.getName(RefU, Kind)) return name; } } return nullptr; } void DWARFDebugInfoEntryMinimal::getCallerFrame(const DWARFUnit *U, uint32_t &CallFile, uint32_t &CallLine, uint32_t &CallColumn) const { CallFile = getAttributeValueAsUnsignedConstant(U, DW_AT_call_file, 0); CallLine = getAttributeValueAsUnsignedConstant(U, DW_AT_call_line, 0); CallColumn = getAttributeValueAsUnsignedConstant(U, DW_AT_call_column, 0); } DWARFDebugInfoEntryInlinedChain DWARFDebugInfoEntryMinimal::getInlinedChainForAddress( const DWARFUnit *U, const uint64_t Address) const { DWARFDebugInfoEntryInlinedChain InlinedChain; InlinedChain.U = U; if (isNULL()) return InlinedChain; for (const DWARFDebugInfoEntryMinimal *DIE = this; DIE; ) { // Append current DIE to inlined chain only if it has correct tag // (e.g. it is not a lexical block). if (DIE->isSubroutineDIE()) { InlinedChain.DIEs.push_back(*DIE); } // Try to get child which also contains provided address. const DWARFDebugInfoEntryMinimal *Child = DIE->getFirstChild(); while (Child) { if (Child->addressRangeContainsAddress(U, Address)) { // Assume there is only one such child. break; } Child = Child->getSibling(); } DIE = Child; } // Reverse the obtained chain to make the root of inlined chain last. std::reverse(InlinedChain.DIEs.begin(), InlinedChain.DIEs.end()); return InlinedChain; }