| //===-- COFFDump.cpp - COFF-specific dumper ---------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| /// |
| /// \file |
| /// \brief This file implements the COFF-specific dumper for llvm-objdump. |
| /// It outputs the Win64 EH data structures as plain text. |
| /// The encoding of the unwind codes is decribed in MSDN: |
| /// http://msdn.microsoft.com/en-us/library/ck9asaa9.aspx |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm-objdump.h" |
| #include "llvm/Object/COFF.h" |
| #include "llvm/Object/ObjectFile.h" |
| #include "llvm/Support/Format.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include "llvm/Support/Win64EH.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Support/system_error.h" |
| #include <algorithm> |
| #include <cstring> |
| |
| using namespace llvm; |
| using namespace object; |
| using namespace llvm::Win64EH; |
| |
| // Returns the name of the unwind code. |
| static StringRef getUnwindCodeTypeName(uint8_t Code) { |
| switch(Code) { |
| default: llvm_unreachable("Invalid unwind code"); |
| case UOP_PushNonVol: return "UOP_PushNonVol"; |
| case UOP_AllocLarge: return "UOP_AllocLarge"; |
| case UOP_AllocSmall: return "UOP_AllocSmall"; |
| case UOP_SetFPReg: return "UOP_SetFPReg"; |
| case UOP_SaveNonVol: return "UOP_SaveNonVol"; |
| case UOP_SaveNonVolBig: return "UOP_SaveNonVolBig"; |
| case UOP_SaveXMM128: return "UOP_SaveXMM128"; |
| case UOP_SaveXMM128Big: return "UOP_SaveXMM128Big"; |
| case UOP_PushMachFrame: return "UOP_PushMachFrame"; |
| } |
| } |
| |
| // Returns the name of a referenced register. |
| static StringRef getUnwindRegisterName(uint8_t Reg) { |
| switch(Reg) { |
| default: llvm_unreachable("Invalid register"); |
| case 0: return "RAX"; |
| case 1: return "RCX"; |
| case 2: return "RDX"; |
| case 3: return "RBX"; |
| case 4: return "RSP"; |
| case 5: return "RBP"; |
| case 6: return "RSI"; |
| case 7: return "RDI"; |
| case 8: return "R8"; |
| case 9: return "R9"; |
| case 10: return "R10"; |
| case 11: return "R11"; |
| case 12: return "R12"; |
| case 13: return "R13"; |
| case 14: return "R14"; |
| case 15: return "R15"; |
| } |
| } |
| |
| // Calculates the number of array slots required for the unwind code. |
| static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) { |
| switch (UnwindCode.getUnwindOp()) { |
| default: llvm_unreachable("Invalid unwind code"); |
| case UOP_PushNonVol: |
| case UOP_AllocSmall: |
| case UOP_SetFPReg: |
| case UOP_PushMachFrame: |
| return 1; |
| case UOP_SaveNonVol: |
| case UOP_SaveXMM128: |
| return 2; |
| case UOP_SaveNonVolBig: |
| case UOP_SaveXMM128Big: |
| return 3; |
| case UOP_AllocLarge: |
| return (UnwindCode.getOpInfo() == 0) ? 2 : 3; |
| } |
| } |
| |
| // Prints one unwind code. Because an unwind code can occupy up to 3 slots in |
| // the unwind codes array, this function requires that the correct number of |
| // slots is provided. |
| static void printUnwindCode(ArrayRef<UnwindCode> UCs) { |
| assert(UCs.size() >= getNumUsedSlots(UCs[0])); |
| outs() << format(" 0x%02x: ", unsigned(UCs[0].u.CodeOffset)) |
| << getUnwindCodeTypeName(UCs[0].getUnwindOp()); |
| switch (UCs[0].getUnwindOp()) { |
| case UOP_PushNonVol: |
| outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo()); |
| break; |
| case UOP_AllocLarge: |
| if (UCs[0].getOpInfo() == 0) { |
| outs() << " " << UCs[1].FrameOffset; |
| } else { |
| outs() << " " << UCs[1].FrameOffset |
| + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16); |
| } |
| break; |
| case UOP_AllocSmall: |
| outs() << " " << ((UCs[0].getOpInfo() + 1) * 8); |
| break; |
| case UOP_SetFPReg: |
| outs() << " "; |
| break; |
| case UOP_SaveNonVol: |
| outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo()) |
| << format(" [0x%04x]", 8 * UCs[1].FrameOffset); |
| break; |
| case UOP_SaveNonVolBig: |
| outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo()) |
| << format(" [0x%08x]", UCs[1].FrameOffset |
| + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16)); |
| break; |
| case UOP_SaveXMM128: |
| outs() << " XMM" << static_cast<uint32_t>(UCs[0].getOpInfo()) |
| << format(" [0x%04x]", 16 * UCs[1].FrameOffset); |
| break; |
| case UOP_SaveXMM128Big: |
| outs() << " XMM" << UCs[0].getOpInfo() |
| << format(" [0x%08x]", UCs[1].FrameOffset |
| + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16)); |
| break; |
| case UOP_PushMachFrame: |
| outs() << " " << (UCs[0].getOpInfo() ? "w/o" : "w") |
| << " error code"; |
| break; |
| } |
| outs() << "\n"; |
| } |
| |
| static void printAllUnwindCodes(ArrayRef<UnwindCode> UCs) { |
| for (const UnwindCode *I = UCs.begin(), *E = UCs.end(); I < E; ) { |
| unsigned UsedSlots = getNumUsedSlots(*I); |
| if (UsedSlots > UCs.size()) { |
| outs() << "Unwind data corrupted: Encountered unwind op " |
| << getUnwindCodeTypeName((*I).getUnwindOp()) |
| << " which requires " << UsedSlots |
| << " slots, but only " << UCs.size() |
| << " remaining in buffer"; |
| return ; |
| } |
| printUnwindCode(ArrayRef<UnwindCode>(I, E)); |
| I += UsedSlots; |
| } |
| } |
| |
| // Given a symbol sym this functions returns the address and section of it. |
| static error_code resolveSectionAndAddress(const COFFObjectFile *Obj, |
| const SymbolRef &Sym, |
| const coff_section *&ResolvedSection, |
| uint64_t &ResolvedAddr) { |
| if (error_code ec = Sym.getAddress(ResolvedAddr)) return ec; |
| section_iterator iter(Obj->begin_sections()); |
| if (error_code ec = Sym.getSection(iter)) return ec; |
| ResolvedSection = Obj->getCOFFSection(iter); |
| return object_error::success; |
| } |
| |
| // Given a vector of relocations for a section and an offset into this section |
| // the function returns the symbol used for the relocation at the offset. |
| static error_code resolveSymbol(const std::vector<RelocationRef> &Rels, |
| uint64_t Offset, SymbolRef &Sym) { |
| for (std::vector<RelocationRef>::const_iterator I = Rels.begin(), |
| E = Rels.end(); |
| I != E; ++I) { |
| uint64_t Ofs; |
| if (error_code ec = I->getOffset(Ofs)) return ec; |
| if (Ofs == Offset) { |
| if (error_code ec = I->getSymbol(Sym)) return ec; |
| break; |
| } |
| } |
| return object_error::success; |
| } |
| |
| // Given a vector of relocations for a section and an offset into this section |
| // the function resolves the symbol used for the relocation at the offset and |
| // returns the section content and the address inside the content pointed to |
| // by the symbol. |
| static error_code getSectionContents(const COFFObjectFile *Obj, |
| const std::vector<RelocationRef> &Rels, |
| uint64_t Offset, |
| ArrayRef<uint8_t> &Contents, |
| uint64_t &Addr) { |
| SymbolRef Sym; |
| if (error_code ec = resolveSymbol(Rels, Offset, Sym)) return ec; |
| const coff_section *Section; |
| if (error_code ec = resolveSectionAndAddress(Obj, Sym, Section, Addr)) |
| return ec; |
| if (error_code ec = Obj->getSectionContents(Section, Contents)) return ec; |
| return object_error::success; |
| } |
| |
| // Given a vector of relocations for a section and an offset into this section |
| // the function returns the name of the symbol used for the relocation at the |
| // offset. |
| static error_code resolveSymbolName(const std::vector<RelocationRef> &Rels, |
| uint64_t Offset, StringRef &Name) { |
| SymbolRef Sym; |
| if (error_code ec = resolveSymbol(Rels, Offset, Sym)) return ec; |
| if (error_code ec = Sym.getName(Name)) return ec; |
| return object_error::success; |
| } |
| |
| static void printCOFFSymbolAddress(llvm::raw_ostream &Out, |
| const std::vector<RelocationRef> &Rels, |
| uint64_t Offset, uint32_t Disp) { |
| StringRef Sym; |
| if (error_code ec = resolveSymbolName(Rels, Offset, Sym)) { |
| error(ec); |
| return ; |
| } |
| Out << Sym; |
| if (Disp > 0) |
| Out << format(" + 0x%04x", Disp); |
| } |
| |
| void llvm::printCOFFUnwindInfo(const COFFObjectFile *Obj) { |
| const coff_file_header *Header; |
| if (error(Obj->getHeader(Header))) return; |
| |
| if (Header->Machine != COFF::IMAGE_FILE_MACHINE_AMD64) { |
| errs() << "Unsupported image machine type " |
| "(currently only AMD64 is supported).\n"; |
| return; |
| } |
| |
| const coff_section *Pdata = 0; |
| |
| error_code ec; |
| for (section_iterator SI = Obj->begin_sections(), |
| SE = Obj->end_sections(); |
| SI != SE; SI.increment(ec)) { |
| if (error(ec)) return; |
| |
| StringRef Name; |
| if (error(SI->getName(Name))) continue; |
| |
| if (Name != ".pdata") continue; |
| |
| Pdata = Obj->getCOFFSection(SI); |
| std::vector<RelocationRef> Rels; |
| for (relocation_iterator RI = SI->begin_relocations(), |
| RE = SI->end_relocations(); |
| RI != RE; RI.increment(ec)) { |
| if (error(ec)) break; |
| Rels.push_back(*RI); |
| } |
| |
| // Sort relocations by address. |
| std::sort(Rels.begin(), Rels.end(), RelocAddressLess); |
| |
| ArrayRef<uint8_t> Contents; |
| if (error(Obj->getSectionContents(Pdata, Contents))) continue; |
| if (Contents.empty()) continue; |
| |
| ArrayRef<RuntimeFunction> RFs( |
| reinterpret_cast<const RuntimeFunction *>(Contents.data()), |
| Contents.size() / sizeof(RuntimeFunction)); |
| for (const RuntimeFunction *I = RFs.begin(), *E = RFs.end(); I < E; ++I) { |
| const uint64_t SectionOffset = std::distance(RFs.begin(), I) |
| * sizeof(RuntimeFunction); |
| |
| outs() << "Function Table:\n"; |
| |
| outs() << " Start Address: "; |
| printCOFFSymbolAddress(outs(), Rels, SectionOffset + |
| /*offsetof(RuntimeFunction, StartAddress)*/ 0, |
| I->StartAddress); |
| outs() << "\n"; |
| |
| outs() << " End Address: "; |
| printCOFFSymbolAddress(outs(), Rels, SectionOffset + |
| /*offsetof(RuntimeFunction, EndAddress)*/ 4, |
| I->EndAddress); |
| outs() << "\n"; |
| |
| outs() << " Unwind Info Address: "; |
| printCOFFSymbolAddress(outs(), Rels, SectionOffset + |
| /*offsetof(RuntimeFunction, UnwindInfoOffset)*/ 8, |
| I->UnwindInfoOffset); |
| outs() << "\n"; |
| |
| ArrayRef<uint8_t> XContents; |
| uint64_t UnwindInfoOffset = 0; |
| if (error(getSectionContents(Obj, Rels, SectionOffset + |
| /*offsetof(RuntimeFunction, UnwindInfoOffset)*/ 8, |
| XContents, UnwindInfoOffset))) continue; |
| if (XContents.empty()) continue; |
| |
| UnwindInfoOffset += I->UnwindInfoOffset; |
| if (UnwindInfoOffset > XContents.size()) continue; |
| |
| const Win64EH::UnwindInfo *UI = |
| reinterpret_cast<const Win64EH::UnwindInfo *> |
| (XContents.data() + UnwindInfoOffset); |
| |
| // The casts to int are required in order to output the value as number. |
| // Without the casts the value would be interpreted as char data (which |
| // results in garbage output). |
| outs() << " Version: " << static_cast<int>(UI->getVersion()) << "\n"; |
| outs() << " Flags: " << static_cast<int>(UI->getFlags()); |
| if (UI->getFlags()) { |
| if (UI->getFlags() & UNW_ExceptionHandler) |
| outs() << " UNW_ExceptionHandler"; |
| if (UI->getFlags() & UNW_TerminateHandler) |
| outs() << " UNW_TerminateHandler"; |
| if (UI->getFlags() & UNW_ChainInfo) |
| outs() << " UNW_ChainInfo"; |
| } |
| outs() << "\n"; |
| outs() << " Size of prolog: " |
| << static_cast<int>(UI->PrologSize) << "\n"; |
| outs() << " Number of Codes: " |
| << static_cast<int>(UI->NumCodes) << "\n"; |
| // Maybe this should move to output of UOP_SetFPReg? |
| if (UI->getFrameRegister()) { |
| outs() << " Frame register: " |
| << getUnwindRegisterName(UI->getFrameRegister()) |
| << "\n"; |
| outs() << " Frame offset: " |
| << 16 * UI->getFrameOffset() |
| << "\n"; |
| } else { |
| outs() << " No frame pointer used\n"; |
| } |
| if (UI->getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) { |
| // FIXME: Output exception handler data |
| } else if (UI->getFlags() & UNW_ChainInfo) { |
| // FIXME: Output chained unwind info |
| } |
| |
| if (UI->NumCodes) |
| outs() << " Unwind Codes:\n"; |
| |
| printAllUnwindCodes(ArrayRef<UnwindCode>(&UI->UnwindCodes[0], |
| UI->NumCodes)); |
| |
| outs() << "\n\n"; |
| outs().flush(); |
| } |
| } |
| } |
