//===-- DWARFContext.cpp --------------------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "DWARFContext.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/StringSwitch.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Support/Compression.h" #include "llvm/Support/Dwarf.h" #include "llvm/Support/Format.h" #include "llvm/Support/Path.h" #include "llvm/Support/raw_ostream.h" #include using namespace llvm; using namespace dwarf; using namespace object; typedef DWARFDebugLine::LineTable DWARFLineTable; void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType) { if (DumpType == DIDT_All || DumpType == DIDT_Abbrev) { OS << ".debug_abbrev contents:\n"; getDebugAbbrev()->dump(OS); } if (DumpType == DIDT_All || DumpType == DIDT_Info) { OS << "\n.debug_info contents:\n"; for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i) getCompileUnitAtIndex(i)->dump(OS); } if (DumpType == DIDT_All || DumpType == DIDT_Frames) { OS << "\n.debug_frame contents:\n"; getDebugFrame()->dump(OS); } uint32_t offset = 0; if (DumpType == DIDT_All || DumpType == DIDT_Aranges) { OS << "\n.debug_aranges contents:\n"; DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0); DWARFDebugArangeSet set; while (set.extract(arangesData, &offset)) set.dump(OS); } uint8_t savedAddressByteSize = 0; if (DumpType == DIDT_All || DumpType == DIDT_Line) { OS << "\n.debug_line contents:\n"; for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i) { DWARFCompileUnit *cu = getCompileUnitAtIndex(i); savedAddressByteSize = cu->getAddressByteSize(); unsigned stmtOffset = cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list, -1U); if (stmtOffset != -1U) { DataExtractor lineData(getLineSection(), isLittleEndian(), savedAddressByteSize); DWARFDebugLine::DumpingState state(OS); DWARFDebugLine::parseStatementTable(lineData, &lineRelocMap(), &stmtOffset, state); } } } if (DumpType == DIDT_All || DumpType == DIDT_Str) { OS << "\n.debug_str contents:\n"; DataExtractor strData(getStringSection(), isLittleEndian(), 0); offset = 0; uint32_t strOffset = 0; while (const char *s = strData.getCStr(&offset)) { OS << format("0x%8.8x: \"%s\"\n", strOffset, s); strOffset = offset; } } if (DumpType == DIDT_All || DumpType == DIDT_Ranges) { OS << "\n.debug_ranges contents:\n"; // In fact, different compile units may have different address byte // sizes, but for simplicity we just use the address byte size of the last // compile unit (there is no easy and fast way to associate address range // list and the compile unit it describes). DataExtractor rangesData(getRangeSection(), isLittleEndian(), savedAddressByteSize); offset = 0; DWARFDebugRangeList rangeList; while (rangeList.extract(rangesData, &offset)) rangeList.dump(OS); } if (DumpType == DIDT_All || DumpType == DIDT_Pubnames) { OS << "\n.debug_pubnames contents:\n"; DataExtractor pubNames(getPubNamesSection(), isLittleEndian(), 0); offset = 0; OS << "Length: " << pubNames.getU32(&offset) << "\n"; OS << "Version: " << pubNames.getU16(&offset) << "\n"; OS << "Offset in .debug_info: " << pubNames.getU32(&offset) << "\n"; OS << "Size: " << pubNames.getU32(&offset) << "\n"; OS << "\n Offset Name\n"; while (offset < getPubNamesSection().size()) { uint32_t n = pubNames.getU32(&offset); if (n == 0) break; OS << format("%8x ", n); OS << pubNames.getCStr(&offset) << "\n"; } } if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo) { const DWARFDebugAbbrev *D = getDebugAbbrevDWO(); if (D) { OS << "\n.debug_abbrev.dwo contents:\n"; getDebugAbbrevDWO()->dump(OS); } } if (DumpType == DIDT_All || DumpType == DIDT_InfoDwo) if (getNumDWOCompileUnits()) { OS << "\n.debug_info.dwo contents:\n"; for (unsigned i = 0, e = getNumDWOCompileUnits(); i != e; ++i) getDWOCompileUnitAtIndex(i)->dump(OS); } if (DumpType == DIDT_All || DumpType == DIDT_StrDwo) if (!getStringDWOSection().empty()) { OS << "\n.debug_str.dwo contents:\n"; DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0); offset = 0; uint32_t strDWOOffset = 0; while (const char *s = strDWOData.getCStr(&offset)) { OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s); strDWOOffset = offset; } } if (DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo) if (!getStringOffsetDWOSection().empty()) { OS << "\n.debug_str_offsets.dwo contents:\n"; DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(), 0); offset = 0; uint64_t size = getStringOffsetDWOSection().size(); while (offset < size) { OS << format("0x%8.8x: ", offset); OS << format("%8.8x\n", strOffsetExt.getU32(&offset)); } } } const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() { if (Abbrev) return Abbrev.get(); DataExtractor abbrData(getAbbrevSection(), isLittleEndian(), 0); Abbrev.reset(new DWARFDebugAbbrev()); Abbrev->parse(abbrData); return Abbrev.get(); } const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() { if (AbbrevDWO) return AbbrevDWO.get(); DataExtractor abbrData(getAbbrevDWOSection(), isLittleEndian(), 0); AbbrevDWO.reset(new DWARFDebugAbbrev()); AbbrevDWO->parse(abbrData); return AbbrevDWO.get(); } const DWARFDebugAranges *DWARFContext::getDebugAranges() { if (Aranges) return Aranges.get(); DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0); Aranges.reset(new DWARFDebugAranges()); Aranges->extract(arangesData); // Generate aranges from DIEs: even if .debug_aranges section is present, // it may describe only a small subset of compilation units, so we need to // manually build aranges for the rest of them. Aranges->generate(this); return Aranges.get(); } const DWARFDebugFrame *DWARFContext::getDebugFrame() { if (DebugFrame) return DebugFrame.get(); // There's a "bug" in the DWARFv3 standard with respect to the target address // size within debug frame sections. While DWARF is supposed to be independent // of its container, FDEs have fields with size being "target address size", // which isn't specified in DWARF in general. It's only specified for CUs, but // .eh_frame can appear without a .debug_info section. Follow the example of // other tools (libdwarf) and extract this from the container (ObjectFile // provides this information). This problem is fixed in DWARFv4 // See this dwarf-discuss discussion for more details: // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html DataExtractor debugFrameData(getDebugFrameSection(), isLittleEndian(), getAddressSize()); DebugFrame.reset(new DWARFDebugFrame()); DebugFrame->parse(debugFrameData); return DebugFrame.get(); } const DWARFLineTable * DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) { if (!Line) Line.reset(new DWARFDebugLine(&lineRelocMap())); unsigned stmtOffset = cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list, -1U); if (stmtOffset == -1U) return 0; // No line table for this compile unit. // See if the line table is cached. if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset)) return lt; // We have to parse it first. DataExtractor lineData(getLineSection(), isLittleEndian(), cu->getAddressByteSize()); return Line->getOrParseLineTable(lineData, stmtOffset); } void DWARFContext::parseCompileUnits() { uint32_t offset = 0; const DataExtractor &DIData = DataExtractor(getInfoSection(), isLittleEndian(), 0); while (DIData.isValidOffset(offset)) { CUs.push_back(DWARFCompileUnit(getDebugAbbrev(), getInfoSection(), getAbbrevSection(), getRangeSection(), getStringSection(), StringRef(), getAddrSection(), &infoRelocMap(), isLittleEndian())); if (!CUs.back().extract(DIData, &offset)) { CUs.pop_back(); break; } offset = CUs.back().getNextCompileUnitOffset(); } } void DWARFContext::parseDWOCompileUnits() { uint32_t offset = 0; const DataExtractor &DIData = DataExtractor(getInfoDWOSection(), isLittleEndian(), 0); while (DIData.isValidOffset(offset)) { DWOCUs.push_back(DWARFCompileUnit(getDebugAbbrevDWO(), getInfoDWOSection(), getAbbrevDWOSection(), getRangeDWOSection(), getStringDWOSection(), getStringOffsetDWOSection(), getAddrSection(), &infoDWORelocMap(), isLittleEndian())); if (!DWOCUs.back().extract(DIData, &offset)) { DWOCUs.pop_back(); break; } offset = DWOCUs.back().getNextCompileUnitOffset(); } } namespace { struct OffsetComparator { bool operator()(const DWARFCompileUnit &LHS, const DWARFCompileUnit &RHS) const { return LHS.getOffset() < RHS.getOffset(); } bool operator()(const DWARFCompileUnit &LHS, uint32_t RHS) const { return LHS.getOffset() < RHS; } bool operator()(uint32_t LHS, const DWARFCompileUnit &RHS) const { return LHS < RHS.getOffset(); } }; } DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) { if (CUs.empty()) parseCompileUnits(); DWARFCompileUnit *CU = std::lower_bound(CUs.begin(), CUs.end(), Offset, OffsetComparator()); if (CU != CUs.end()) return &*CU; return 0; } DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) { // First, get the offset of the compile unit. uint32_t CUOffset = getDebugAranges()->findAddress(Address); // Retrieve the compile unit. return getCompileUnitForOffset(CUOffset); } static bool getFileNameForCompileUnit(DWARFCompileUnit *CU, const DWARFLineTable *LineTable, uint64_t FileIndex, bool NeedsAbsoluteFilePath, std::string &FileName) { if (CU == 0 || LineTable == 0 || !LineTable->getFileNameByIndex(FileIndex, NeedsAbsoluteFilePath, FileName)) return false; if (NeedsAbsoluteFilePath && sys::path::is_relative(FileName)) { // We may still need to append compilation directory of compile unit. SmallString<16> AbsolutePath; if (const char *CompilationDir = CU->getCompilationDir()) { sys::path::append(AbsolutePath, CompilationDir); } sys::path::append(AbsolutePath, FileName); FileName = AbsolutePath.str(); } return true; } static bool getFileLineInfoForCompileUnit(DWARFCompileUnit *CU, const DWARFLineTable *LineTable, uint64_t Address, bool NeedsAbsoluteFilePath, std::string &FileName, uint32_t &Line, uint32_t &Column) { if (CU == 0 || LineTable == 0) return false; // Get the index of row we're looking for in the line table. uint32_t RowIndex = LineTable->lookupAddress(Address); if (RowIndex == -1U) return false; // Take file number and line/column from the row. const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex]; if (!getFileNameForCompileUnit(CU, LineTable, Row.File, NeedsAbsoluteFilePath, FileName)) return false; Line = Row.Line; Column = Row.Column; return true; } DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address, DILineInfoSpecifier Specifier) { DWARFCompileUnit *CU = getCompileUnitForAddress(Address); if (!CU) return DILineInfo(); std::string FileName = ""; std::string FunctionName = ""; uint32_t Line = 0; uint32_t Column = 0; if (Specifier.needs(DILineInfoSpecifier::FunctionName)) { // The address may correspond to instruction in some inlined function, // so we have to build the chain of inlined functions and take the // name of the topmost function in it. const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain = CU->getInlinedChainForAddress(Address); if (InlinedChain.size() > 0) { const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain[0]; if (const char *Name = TopFunctionDIE.getSubroutineName(CU)) FunctionName = Name; } } if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) { const DWARFLineTable *LineTable = getLineTableForCompileUnit(CU); const bool NeedsAbsoluteFilePath = Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath); getFileLineInfoForCompileUnit(CU, LineTable, Address, NeedsAbsoluteFilePath, FileName, Line, Column); } return DILineInfo(StringRef(FileName), StringRef(FunctionName), Line, Column); } DILineInfoTable DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size, DILineInfoSpecifier Specifier) { DILineInfoTable Lines; DWARFCompileUnit *CU = getCompileUnitForAddress(Address); if (!CU) return Lines; std::string FunctionName = ""; if (Specifier.needs(DILineInfoSpecifier::FunctionName)) { // The address may correspond to instruction in some inlined function, // so we have to build the chain of inlined functions and take the // name of the topmost function in it. const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain = CU->getInlinedChainForAddress(Address); if (InlinedChain.size() > 0) { const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain[0]; if (const char *Name = TopFunctionDIE.getSubroutineName(CU)) FunctionName = Name; } } StringRef FuncNameRef = StringRef(FunctionName); // If the Specifier says we don't need FileLineInfo, just // return the top-most function at the starting address. if (!Specifier.needs(DILineInfoSpecifier::FileLineInfo)) { Lines.push_back(std::make_pair(Address, DILineInfo(StringRef(""), FuncNameRef, 0, 0))); return Lines; } const DWARFLineTable *LineTable = getLineTableForCompileUnit(CU); const bool NeedsAbsoluteFilePath = Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath); // Get the index of row we're looking for in the line table. std::vector RowVector; if (!LineTable->lookupAddressRange(Address, Size, RowVector)) return Lines; uint32_t NumRows = RowVector.size(); for (uint32_t i = 0; i < NumRows; ++i) { uint32_t RowIndex = RowVector[i]; // Take file number and line/column from the row. const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex]; std::string FileName = ""; getFileNameForCompileUnit(CU, LineTable, Row.File, NeedsAbsoluteFilePath, FileName); Lines.push_back(std::make_pair(Row.Address, DILineInfo(StringRef(FileName), FuncNameRef, Row.Line, Row.Column))); } return Lines; } DIInliningInfo DWARFContext::getInliningInfoForAddress(uint64_t Address, DILineInfoSpecifier Specifier) { DWARFCompileUnit *CU = getCompileUnitForAddress(Address); if (!CU) return DIInliningInfo(); const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain = CU->getInlinedChainForAddress(Address); if (InlinedChain.size() == 0) return DIInliningInfo(); DIInliningInfo InliningInfo; uint32_t CallFile = 0, CallLine = 0, CallColumn = 0; const DWARFLineTable *LineTable = 0; for (uint32_t i = 0, n = InlinedChain.size(); i != n; i++) { const DWARFDebugInfoEntryMinimal &FunctionDIE = InlinedChain[i]; std::string FileName = ""; std::string FunctionName = ""; uint32_t Line = 0; uint32_t Column = 0; // Get function name if necessary. if (Specifier.needs(DILineInfoSpecifier::FunctionName)) { if (const char *Name = FunctionDIE.getSubroutineName(CU)) FunctionName = Name; } if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) { const bool NeedsAbsoluteFilePath = Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath); if (i == 0) { // For the topmost frame, initialize the line table of this // compile unit and fetch file/line info from it. LineTable = getLineTableForCompileUnit(CU); // For the topmost routine, get file/line info from line table. getFileLineInfoForCompileUnit(CU, LineTable, Address, NeedsAbsoluteFilePath, FileName, Line, Column); } else { // Otherwise, use call file, call line and call column from // previous DIE in inlined chain. getFileNameForCompileUnit(CU, LineTable, CallFile, NeedsAbsoluteFilePath, FileName); Line = CallLine; Column = CallColumn; } // Get call file/line/column of a current DIE. if (i + 1 < n) { FunctionDIE.getCallerFrame(CU, CallFile, CallLine, CallColumn); } } DILineInfo Frame(StringRef(FileName), StringRef(FunctionName), Line, Column); InliningInfo.addFrame(Frame); } return InliningInfo; } static bool consumeCompressedDebugSectionHeader(StringRef &data, uint64_t &OriginalSize) { // Consume "ZLIB" prefix. if (!data.startswith("ZLIB")) return false; data = data.substr(4); // Consume uncompressed section size (big-endian 8 bytes). DataExtractor extractor(data, false, 8); uint32_t Offset = 0; OriginalSize = extractor.getU64(&Offset); if (Offset == 0) return false; data = data.substr(Offset); return true; } DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) : IsLittleEndian(Obj->isLittleEndian()), AddressSize(Obj->getBytesInAddress()) { error_code ec; for (object::section_iterator i = Obj->begin_sections(), e = Obj->end_sections(); i != e; i.increment(ec)) { StringRef name; i->getName(name); StringRef data; i->getContents(data); name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes. // Check if debug info section is compressed with zlib. if (name.startswith("zdebug_")) { uint64_t OriginalSize; if (!zlib::isAvailable() || !consumeCompressedDebugSectionHeader(data, OriginalSize)) continue; OwningPtr UncompressedSection; if (zlib::uncompress(data, UncompressedSection, OriginalSize) != zlib::StatusOK) continue; // Make data point to uncompressed section contents and save its contents. name = name.substr(1); data = UncompressedSection->getBuffer(); UncompressedSections.push_back(UncompressedSection.take()); } StringRef *Section = StringSwitch(name) .Case("debug_info", &InfoSection) .Case("debug_abbrev", &AbbrevSection) .Case("debug_line", &LineSection) .Case("debug_aranges", &ARangeSection) .Case("debug_frame", &DebugFrameSection) .Case("debug_str", &StringSection) .Case("debug_ranges", &RangeSection) .Case("debug_pubnames", &PubNamesSection) .Case("debug_info.dwo", &InfoDWOSection) .Case("debug_abbrev.dwo", &AbbrevDWOSection) .Case("debug_str.dwo", &StringDWOSection) .Case("debug_str_offsets.dwo", &StringOffsetDWOSection) .Case("debug_addr", &AddrSection) // Any more debug info sections go here. .Default(0); if (Section) { *Section = data; if (name == "debug_ranges") { // FIXME: Use the other dwo range section when we emit it. RangeDWOSection = data; } } section_iterator RelocatedSection = i->getRelocatedSection(); if (RelocatedSection == Obj->end_sections()) continue; StringRef RelSecName; RelocatedSection->getName(RelSecName); RelSecName = RelSecName.substr( RelSecName.find_first_not_of("._")); // Skip . and _ prefixes. // TODO: Add support for relocations in other sections as needed. // Record relocations for the debug_info and debug_line sections. RelocAddrMap *Map = StringSwitch(RelSecName) .Case("debug_info", &InfoRelocMap) .Case("debug_info.dwo", &InfoDWORelocMap) .Case("debug_line", &LineRelocMap) .Default(0); if (!Map) continue; if (i->begin_relocations() != i->end_relocations()) { uint64_t SectionSize; RelocatedSection->getSize(SectionSize); for (object::relocation_iterator reloc_i = i->begin_relocations(), reloc_e = i->end_relocations(); reloc_i != reloc_e; reloc_i.increment(ec)) { uint64_t Address; reloc_i->getOffset(Address); uint64_t Type; reloc_i->getType(Type); uint64_t SymAddr = 0; // ELF relocations may need the symbol address if (Obj->isELF()) { object::symbol_iterator Sym = reloc_i->getSymbol(); Sym->getAddress(SymAddr); } object::RelocVisitor V(Obj->getFileFormatName()); // The section address is always 0 for debug sections. object::RelocToApply R(V.visit(Type, *reloc_i, 0, SymAddr)); if (V.error()) { SmallString<32> Name; error_code ec(reloc_i->getTypeName(Name)); if (ec) { errs() << "Aaaaaa! Nameless relocation! Aaaaaa!\n"; } errs() << "error: failed to compute relocation: " << Name << "\n"; continue; } if (Address + R.Width > SectionSize) { errs() << "error: " << R.Width << "-byte relocation starting " << Address << " bytes into section " << name << " which is " << SectionSize << " bytes long.\n"; continue; } if (R.Width > 8) { errs() << "error: can't handle a relocation of more than 8 bytes at " "a time.\n"; continue; } DEBUG(dbgs() << "Writing " << format("%p", R.Value) << " at " << format("%p", Address) << " with width " << format("%d", R.Width) << "\n"); Map->insert(std::make_pair(Address, std::make_pair(R.Width, R.Value))); } } } } DWARFContextInMemory::~DWARFContextInMemory() { DeleteContainerPointers(UncompressedSections); } void DWARFContextInMemory::anchor() { }