DWARFDebugFrame.cpp revision ba42625074aa7f4f1324a5d6666bd0e302b57f2b
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===-- DWARFDebugFrame.h - Parsing of .debug_frame -------------*- C++ -*-===// 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The LLVM Compiler Infrastructure 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This file is distributed under the University of Illinois Open Source 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// License. See LICENSE.TXT for details. 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "DWARFDebugFrame.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/ADT/SmallString.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/Support/DataTypes.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/Support/Dwarf.h" 145d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)#include "llvm/Support/Format.h" 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using namespace llvm; 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using namespace dwarf; 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class llvm::FrameEntry { 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)public: 225d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) enum FrameKind {FK_CIE, FK_FDE}; 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) FrameEntry(FrameKind K, DataExtractor D, uint64_t Offset, uint64_t Length) 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : Kind(K), Data(D), Offset(Offset), Length(Length) {} 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) FrameKind getKind() const { return Kind; } 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void dumpHeader(raw_ostream &OS) const = 0; 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)protected: 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const FrameKind Kind; 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// \brief The data stream holding the section from which the entry was 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// parsed. 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DataExtractor Data; 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// \brief Offset of this entry in the section. 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t Offset; 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// \brief Entry length as specified in DWARF. 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t Length; 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class CIE : public FrameEntry { 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)public: 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // CIEs (and FDEs) are simply container classes, so the only sensible way to 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // create them is by providing the full parsed contents in the constructor. 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CIE(DataExtractor D, uint64_t Offset, uint64_t Length, uint8_t Version, 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SmallString<8> Augmentation, uint64_t CodeAlignmentFactor, 515d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int64_t DataAlignmentFactor, uint64_t ReturnAddressRegister) 525d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) : FrameEntry(FK_CIE, D, Offset, Length), Version(Version), 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Augmentation(Augmentation), CodeAlignmentFactor(CodeAlignmentFactor), 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DataAlignmentFactor(DataAlignmentFactor), 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ReturnAddressRegister(ReturnAddressRegister) {} 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void dumpHeader(raw_ostream &OS) const { 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << format("%08x %08x %08x CIE", Offset, Length, DW_CIE_ID) << "\n"; 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << format(" Version: %d\n", Version); 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << " Augmentation: \"" << Augmentation << "\"\n"; 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << format(" Code alignment factor: %u\n", CodeAlignmentFactor); 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << format(" Data alignment factor: %d\n", DataAlignmentFactor); 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << format(" Return address column: %d\n", ReturnAddressRegister); 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << "\n"; 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static bool classof(const FrameEntry *FE) { 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return FE->getKind() == FK_CIE; 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)private: 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// The following fields are defined in section 6.4.1 of the DWARF standard v3 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint8_t Version; 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SmallString<8> Augmentation; 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t CodeAlignmentFactor; 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int64_t DataAlignmentFactor; 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t ReturnAddressRegister; 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class FDE : public FrameEntry { 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)public: 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Each FDE has a CIE it's "linked to". Our FDE contains is constructed with 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // an offset to the CIE (provided by parsing the FDE header). The CIE itself 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // is obtained lazily once it's actually required. 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) FDE(DataExtractor D, uint64_t Offset, uint64_t Length, 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int64_t LinkedCIEOffset, uint64_t InitialLocation, uint64_t AddressRange) 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : FrameEntry(FK_FDE, D, Offset, Length), LinkedCIEOffset(LinkedCIEOffset), 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InitialLocation(InitialLocation), AddressRange(AddressRange), 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) LinkedCIE(NULL) {} 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void dumpHeader(raw_ostream &OS) const { 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << format("%08x %08x %08x FDE ", Offset, Length, LinkedCIEOffset); 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << format("cie=%08x pc=%08x...%08x\n", 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) LinkedCIEOffset, InitialLocation, 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InitialLocation + AddressRange); 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) OS << "\n"; 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static bool classof(const FrameEntry *FE) { 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return FE->getKind() == FK_FDE; 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)private: 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /// The following fields are defined in section 6.4.1 of the DWARF standard v3 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t LinkedCIEOffset; 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t InitialLocation; 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t AddressRange; 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CIE *LinkedCIE; 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)DWARFDebugFrame::DWARFDebugFrame() { 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)DWARFDebugFrame::~DWARFDebugFrame() { 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (EntryVector::iterator I = Entries.begin(), E = Entries.end(); 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) I != E; ++I) { 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) delete *I; 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)static void LLVM_ATTRIBUTE_UNUSED dumpDataAux(DataExtractor Data, 126 uint32_t Offset, int Length) { 127 errs() << "DUMP: "; 128 for (int i = 0; i < Length; ++i) { 129 uint8_t c = Data.getU8(&Offset); 130 errs().write_hex(c); errs() << " "; 131 } 132 errs() << "\n"; 133} 134 135 136void DWARFDebugFrame::parse(DataExtractor Data) { 137 uint32_t Offset = 0; 138 139 while (Data.isValidOffset(Offset)) { 140 uint32_t StartOffset = Offset; 141 142 bool IsDWARF64 = false; 143 uint64_t Length = Data.getU32(&Offset); 144 uint64_t Id; 145 146 if (Length == UINT32_MAX) { 147 // DWARF-64 is distinguished by the first 32 bits of the initial length 148 // field being 0xffffffff. Then, the next 64 bits are the actual entry 149 // length. 150 IsDWARF64 = true; 151 Length = Data.getU64(&Offset); 152 } 153 154 // At this point, Offset points to the next field after Length. 155 // Length is the structure size excluding itself. Compute an offset one 156 // past the end of the structure (needed to know how many instructions to 157 // read). 158 // TODO: For honest DWARF64 support, DataExtractor will have to treat 159 // offset_ptr as uint64_t* 160 uint32_t EndStructureOffset = Offset + static_cast<uint32_t>(Length); 161 162 // The Id field's size depends on the DWARF format 163 Id = Data.getUnsigned(&Offset, IsDWARF64 ? 8 : 4); 164 bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID); 165 166 if (IsCIE) { 167 // Note: this is specifically DWARFv3 CIE header structure. It was 168 // changed in DWARFv4. 169 uint8_t Version = Data.getU8(&Offset); 170 const char *Augmentation = Data.getCStr(&Offset); 171 uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset); 172 int64_t DataAlignmentFactor = Data.getSLEB128(&Offset); 173 uint64_t ReturnAddressRegister = Data.getULEB128(&Offset); 174 175 CIE *NewCIE = new CIE(Data, StartOffset, Length, Version, 176 StringRef(Augmentation), CodeAlignmentFactor, 177 DataAlignmentFactor, ReturnAddressRegister); 178 Entries.push_back(NewCIE); 179 } else { 180 // FDE 181 uint64_t CIEPointer = Id; 182 uint64_t InitialLocation = Data.getAddress(&Offset); 183 uint64_t AddressRange = Data.getAddress(&Offset); 184 185 FDE *NewFDE = new FDE(Data, StartOffset, Length, CIEPointer, 186 InitialLocation, AddressRange); 187 Entries.push_back(NewFDE); 188 } 189 190 Offset = EndStructureOffset; 191 } 192} 193 194 195void DWARFDebugFrame::dump(raw_ostream &OS) const { 196 OS << "\n"; 197 for (EntryVector::const_iterator I = Entries.begin(), E = Entries.end(); 198 I != E; ++I) { 199 (*I)->dumpHeader(OS); 200 } 201} 202 203