| //===-- llvm-mc.cpp - Machine Code Hacking Driver ---------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This utility is a simple driver that allows command line hacking on machine |
| // code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "Disassembler.h" |
| #include "llvm/MC/MCAsmBackend.h" |
| #include "llvm/MC/MCAsmInfo.h" |
| #include "llvm/MC/MCCodeEmitter.h" |
| #include "llvm/MC/MCContext.h" |
| #include "llvm/MC/MCInstPrinter.h" |
| #include "llvm/MC/MCInstrInfo.h" |
| #include "llvm/MC/MCObjectFileInfo.h" |
| #include "llvm/MC/MCObjectWriter.h" |
| #include "llvm/MC/MCParser/AsmLexer.h" |
| #include "llvm/MC/MCParser/MCTargetAsmParser.h" |
| #include "llvm/MC/MCRegisterInfo.h" |
| #include "llvm/MC/MCStreamer.h" |
| #include "llvm/MC/MCSubtargetInfo.h" |
| #include "llvm/MC/MCTargetOptionsCommandFlags.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Compression.h" |
| #include "llvm/Support/FileUtilities.h" |
| #include "llvm/Support/FormattedStream.h" |
| #include "llvm/Support/Host.h" |
| #include "llvm/Support/InitLLVM.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include "llvm/Support/TargetRegistry.h" |
| #include "llvm/Support/TargetSelect.h" |
| #include "llvm/Support/ToolOutputFile.h" |
| #include "llvm/Support/WithColor.h" |
| |
| using namespace llvm; |
| |
| static mc::RegisterMCTargetOptionsFlags MOF; |
| |
| static cl::opt<std::string> |
| InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-")); |
| |
| static cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"), |
| cl::value_desc("filename"), |
| cl::init("-")); |
| |
| static cl::opt<std::string> SplitDwarfFile("split-dwarf-file", |
| cl::desc("DWO output filename"), |
| cl::value_desc("filename")); |
| |
| static cl::opt<bool> |
| ShowEncoding("show-encoding", cl::desc("Show instruction encodings")); |
| |
| static cl::opt<bool> RelaxELFRel( |
| "relax-relocations", cl::init(true), |
| cl::desc("Emit R_X86_64_GOTPCRELX instead of R_X86_64_GOTPCREL")); |
| |
| static cl::opt<DebugCompressionType> CompressDebugSections( |
| "compress-debug-sections", cl::ValueOptional, |
| cl::init(DebugCompressionType::None), |
| cl::desc("Choose DWARF debug sections compression:"), |
| cl::values(clEnumValN(DebugCompressionType::None, "none", "No compression"), |
| clEnumValN(DebugCompressionType::Z, "zlib", |
| "Use zlib compression"), |
| clEnumValN(DebugCompressionType::GNU, "zlib-gnu", |
| "Use zlib-gnu compression (deprecated)"))); |
| |
| static cl::opt<bool> |
| ShowInst("show-inst", cl::desc("Show internal instruction representation")); |
| |
| static cl::opt<bool> |
| ShowInstOperands("show-inst-operands", |
| cl::desc("Show instructions operands as parsed")); |
| |
| static cl::opt<unsigned> |
| OutputAsmVariant("output-asm-variant", |
| cl::desc("Syntax variant to use for output printing")); |
| |
| static cl::opt<bool> |
| PrintImmHex("print-imm-hex", cl::init(false), |
| cl::desc("Prefer hex format for immediate values")); |
| |
| static cl::list<std::string> |
| DefineSymbol("defsym", cl::desc("Defines a symbol to be an integer constant")); |
| |
| static cl::opt<bool> |
| PreserveComments("preserve-comments", |
| cl::desc("Preserve Comments in outputted assembly")); |
| |
| enum OutputFileType { |
| OFT_Null, |
| OFT_AssemblyFile, |
| OFT_ObjectFile |
| }; |
| static cl::opt<OutputFileType> |
| FileType("filetype", cl::init(OFT_AssemblyFile), |
| cl::desc("Choose an output file type:"), |
| cl::values( |
| clEnumValN(OFT_AssemblyFile, "asm", |
| "Emit an assembly ('.s') file"), |
| clEnumValN(OFT_Null, "null", |
| "Don't emit anything (for timing purposes)"), |
| clEnumValN(OFT_ObjectFile, "obj", |
| "Emit a native object ('.o') file"))); |
| |
| static cl::list<std::string> |
| IncludeDirs("I", cl::desc("Directory of include files"), |
| cl::value_desc("directory"), cl::Prefix); |
| |
| static cl::opt<std::string> |
| ArchName("arch", cl::desc("Target arch to assemble for, " |
| "see -version for available targets")); |
| |
| static cl::opt<std::string> |
| TripleName("triple", cl::desc("Target triple to assemble for, " |
| "see -version for available targets")); |
| |
| static cl::opt<std::string> |
| MCPU("mcpu", |
| cl::desc("Target a specific cpu type (-mcpu=help for details)"), |
| cl::value_desc("cpu-name"), |
| cl::init("")); |
| |
| static cl::list<std::string> |
| MAttrs("mattr", |
| cl::CommaSeparated, |
| cl::desc("Target specific attributes (-mattr=help for details)"), |
| cl::value_desc("a1,+a2,-a3,...")); |
| |
| static cl::opt<bool> PIC("position-independent", |
| cl::desc("Position independent"), cl::init(false)); |
| |
| static cl::opt<bool> |
| LargeCodeModel("large-code-model", |
| cl::desc("Create cfi directives that assume the code might " |
| "be more than 2gb away")); |
| |
| static cl::opt<bool> |
| NoInitialTextSection("n", cl::desc("Don't assume assembly file starts " |
| "in the text section")); |
| |
| static cl::opt<bool> |
| GenDwarfForAssembly("g", cl::desc("Generate dwarf debugging info for assembly " |
| "source files")); |
| |
| static cl::opt<std::string> |
| DebugCompilationDir("fdebug-compilation-dir", |
| cl::desc("Specifies the debug info's compilation dir")); |
| |
| static cl::list<std::string> |
| DebugPrefixMap("fdebug-prefix-map", |
| cl::desc("Map file source paths in debug info"), |
| cl::value_desc("= separated key-value pairs")); |
| |
| static cl::opt<std::string> |
| MainFileName("main-file-name", |
| cl::desc("Specifies the name we should consider the input file")); |
| |
| static cl::opt<bool> SaveTempLabels("save-temp-labels", |
| cl::desc("Don't discard temporary labels")); |
| |
| static cl::opt<bool> LexMasmIntegers( |
| "masm-integers", |
| cl::desc("Enable binary and hex masm integers (0b110 and 0ABCh)")); |
| |
| static cl::opt<bool> LexMasmHexFloats( |
| "masm-hexfloats", |
| cl::desc("Enable MASM-style hex float initializers (3F800000r)")); |
| |
| static cl::opt<bool> NoExecStack("no-exec-stack", |
| cl::desc("File doesn't need an exec stack")); |
| |
| enum ActionType { |
| AC_AsLex, |
| AC_Assemble, |
| AC_Disassemble, |
| AC_MDisassemble, |
| }; |
| |
| static cl::opt<ActionType> |
| Action(cl::desc("Action to perform:"), |
| cl::init(AC_Assemble), |
| cl::values(clEnumValN(AC_AsLex, "as-lex", |
| "Lex tokens from a .s file"), |
| clEnumValN(AC_Assemble, "assemble", |
| "Assemble a .s file (default)"), |
| clEnumValN(AC_Disassemble, "disassemble", |
| "Disassemble strings of hex bytes"), |
| clEnumValN(AC_MDisassemble, "mdis", |
| "Marked up disassembly of strings of hex bytes"))); |
| |
| static const Target *GetTarget(const char *ProgName) { |
| // Figure out the target triple. |
| if (TripleName.empty()) |
| TripleName = sys::getDefaultTargetTriple(); |
| Triple TheTriple(Triple::normalize(TripleName)); |
| |
| // Get the target specific parser. |
| std::string Error; |
| const Target *TheTarget = TargetRegistry::lookupTarget(ArchName, TheTriple, |
| Error); |
| if (!TheTarget) { |
| WithColor::error(errs(), ProgName) << Error; |
| return nullptr; |
| } |
| |
| // Update the triple name and return the found target. |
| TripleName = TheTriple.getTriple(); |
| return TheTarget; |
| } |
| |
| static std::unique_ptr<ToolOutputFile> GetOutputStream(StringRef Path, |
| sys::fs::OpenFlags Flags) { |
| std::error_code EC; |
| auto Out = std::make_unique<ToolOutputFile>(Path, EC, Flags); |
| if (EC) { |
| WithColor::error() << EC.message() << '\n'; |
| return nullptr; |
| } |
| |
| return Out; |
| } |
| |
| static std::string DwarfDebugFlags; |
| static void setDwarfDebugFlags(int argc, char **argv) { |
| if (!getenv("RC_DEBUG_OPTIONS")) |
| return; |
| for (int i = 0; i < argc; i++) { |
| DwarfDebugFlags += argv[i]; |
| if (i + 1 < argc) |
| DwarfDebugFlags += " "; |
| } |
| } |
| |
| static std::string DwarfDebugProducer; |
| static void setDwarfDebugProducer() { |
| if(!getenv("DEBUG_PRODUCER")) |
| return; |
| DwarfDebugProducer += getenv("DEBUG_PRODUCER"); |
| } |
| |
| static int AsLexInput(SourceMgr &SrcMgr, MCAsmInfo &MAI, |
| raw_ostream &OS) { |
| |
| AsmLexer Lexer(MAI); |
| Lexer.setBuffer(SrcMgr.getMemoryBuffer(SrcMgr.getMainFileID())->getBuffer()); |
| |
| bool Error = false; |
| while (Lexer.Lex().isNot(AsmToken::Eof)) { |
| Lexer.getTok().dump(OS); |
| OS << "\n"; |
| if (Lexer.getTok().getKind() == AsmToken::Error) |
| Error = true; |
| } |
| |
| return Error; |
| } |
| |
| static int fillCommandLineSymbols(MCAsmParser &Parser) { |
| for (auto &I: DefineSymbol) { |
| auto Pair = StringRef(I).split('='); |
| auto Sym = Pair.first; |
| auto Val = Pair.second; |
| |
| if (Sym.empty() || Val.empty()) { |
| WithColor::error() << "defsym must be of the form: sym=value: " << I |
| << "\n"; |
| return 1; |
| } |
| int64_t Value; |
| if (Val.getAsInteger(0, Value)) { |
| WithColor::error() << "value is not an integer: " << Val << "\n"; |
| return 1; |
| } |
| Parser.getContext().setSymbolValue(Parser.getStreamer(), Sym, Value); |
| } |
| return 0; |
| } |
| |
| static int AssembleInput(const char *ProgName, const Target *TheTarget, |
| SourceMgr &SrcMgr, MCContext &Ctx, MCStreamer &Str, |
| MCAsmInfo &MAI, MCSubtargetInfo &STI, |
| MCInstrInfo &MCII, MCTargetOptions const &MCOptions) { |
| std::unique_ptr<MCAsmParser> Parser( |
| createMCAsmParser(SrcMgr, Ctx, Str, MAI)); |
| std::unique_ptr<MCTargetAsmParser> TAP( |
| TheTarget->createMCAsmParser(STI, *Parser, MCII, MCOptions)); |
| |
| if (!TAP) { |
| WithColor::error(errs(), ProgName) |
| << "this target does not support assembly parsing.\n"; |
| return 1; |
| } |
| |
| int SymbolResult = fillCommandLineSymbols(*Parser); |
| if(SymbolResult) |
| return SymbolResult; |
| Parser->setShowParsedOperands(ShowInstOperands); |
| Parser->setTargetParser(*TAP); |
| Parser->getLexer().setLexMasmIntegers(LexMasmIntegers); |
| Parser->getLexer().setLexMasmHexFloats(LexMasmHexFloats); |
| |
| int Res = Parser->Run(NoInitialTextSection); |
| |
| return Res; |
| } |
| |
| int main(int argc, char **argv) { |
| InitLLVM X(argc, argv); |
| |
| // Initialize targets and assembly printers/parsers. |
| llvm::InitializeAllTargetInfos(); |
| llvm::InitializeAllTargetMCs(); |
| llvm::InitializeAllAsmParsers(); |
| llvm::InitializeAllDisassemblers(); |
| |
| // Register the target printer for --version. |
| cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion); |
| |
| cl::ParseCommandLineOptions(argc, argv, "llvm machine code playground\n"); |
| const MCTargetOptions MCOptions = mc::InitMCTargetOptionsFromFlags(); |
| setDwarfDebugFlags(argc, argv); |
| |
| setDwarfDebugProducer(); |
| |
| const char *ProgName = argv[0]; |
| const Target *TheTarget = GetTarget(ProgName); |
| if (!TheTarget) |
| return 1; |
| // Now that GetTarget() has (potentially) replaced TripleName, it's safe to |
| // construct the Triple object. |
| Triple TheTriple(TripleName); |
| |
| ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr = |
| MemoryBuffer::getFileOrSTDIN(InputFilename); |
| if (std::error_code EC = BufferPtr.getError()) { |
| WithColor::error(errs(), ProgName) |
| << InputFilename << ": " << EC.message() << '\n'; |
| return 1; |
| } |
| MemoryBuffer *Buffer = BufferPtr->get(); |
| |
| SourceMgr SrcMgr; |
| |
| // Tell SrcMgr about this buffer, which is what the parser will pick up. |
| SrcMgr.AddNewSourceBuffer(std::move(*BufferPtr), SMLoc()); |
| |
| // Record the location of the include directories so that the lexer can find |
| // it later. |
| SrcMgr.setIncludeDirs(IncludeDirs); |
| |
| std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName)); |
| assert(MRI && "Unable to create target register info!"); |
| |
| std::unique_ptr<MCAsmInfo> MAI( |
| TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions)); |
| assert(MAI && "Unable to create target asm info!"); |
| |
| MAI->setRelaxELFRelocations(RelaxELFRel); |
| |
| if (CompressDebugSections != DebugCompressionType::None) { |
| if (!zlib::isAvailable()) { |
| WithColor::error(errs(), ProgName) |
| << "build tools with zlib to enable -compress-debug-sections"; |
| return 1; |
| } |
| MAI->setCompressDebugSections(CompressDebugSections); |
| } |
| MAI->setPreserveAsmComments(PreserveComments); |
| |
| // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and |
| // MCObjectFileInfo needs a MCContext reference in order to initialize itself. |
| MCObjectFileInfo MOFI; |
| MCContext Ctx(MAI.get(), MRI.get(), &MOFI, &SrcMgr, &MCOptions); |
| MOFI.InitMCObjectFileInfo(TheTriple, PIC, Ctx, LargeCodeModel); |
| |
| if (SaveTempLabels) |
| Ctx.setAllowTemporaryLabels(false); |
| |
| Ctx.setGenDwarfForAssembly(GenDwarfForAssembly); |
| // Default to 4 for dwarf version. |
| unsigned DwarfVersion = MCOptions.DwarfVersion ? MCOptions.DwarfVersion : 4; |
| if (DwarfVersion < 2 || DwarfVersion > 5) { |
| errs() << ProgName << ": Dwarf version " << DwarfVersion |
| << " is not supported." << '\n'; |
| return 1; |
| } |
| Ctx.setDwarfVersion(DwarfVersion); |
| if (MCOptions.Dwarf64) { |
| // The 64-bit DWARF format was introduced in DWARFv3. |
| if (DwarfVersion < 3) { |
| errs() << ProgName |
| << ": the 64-bit DWARF format is not supported for DWARF versions " |
| "prior to 3\n"; |
| return 1; |
| } |
| // 32-bit targets don't support DWARF64, which requires 64-bit relocations. |
| if (MAI->getCodePointerSize() < 8) { |
| errs() << ProgName |
| << ": the 64-bit DWARF format is only supported for 64-bit " |
| "targets\n"; |
| return 1; |
| } |
| // If needsDwarfSectionOffsetDirective is true, we would eventually call |
| // MCStreamer::emitSymbolValue() with IsSectionRelative = true, but that |
| // is supported only for 4-byte long references. |
| if (MAI->needsDwarfSectionOffsetDirective()) { |
| errs() << ProgName << ": the 64-bit DWARF format is not supported for " |
| << TheTriple.normalize() << "\n"; |
| return 1; |
| } |
| Ctx.setDwarfFormat(dwarf::DWARF64); |
| } |
| if (!DwarfDebugFlags.empty()) |
| Ctx.setDwarfDebugFlags(StringRef(DwarfDebugFlags)); |
| if (!DwarfDebugProducer.empty()) |
| Ctx.setDwarfDebugProducer(StringRef(DwarfDebugProducer)); |
| if (!DebugCompilationDir.empty()) |
| Ctx.setCompilationDir(DebugCompilationDir); |
| else { |
| // If no compilation dir is set, try to use the current directory. |
| SmallString<128> CWD; |
| if (!sys::fs::current_path(CWD)) |
| Ctx.setCompilationDir(CWD); |
| } |
| for (const auto &Arg : DebugPrefixMap) { |
| const auto &KV = StringRef(Arg).split('='); |
| Ctx.addDebugPrefixMapEntry(std::string(KV.first), std::string(KV.second)); |
| } |
| if (!MainFileName.empty()) |
| Ctx.setMainFileName(MainFileName); |
| if (GenDwarfForAssembly) |
| Ctx.setGenDwarfRootFile(InputFilename, Buffer->getBuffer()); |
| |
| // Package up features to be passed to target/subtarget |
| std::string FeaturesStr; |
| if (MAttrs.size()) { |
| SubtargetFeatures Features; |
| for (unsigned i = 0; i != MAttrs.size(); ++i) |
| Features.AddFeature(MAttrs[i]); |
| FeaturesStr = Features.getString(); |
| } |
| |
| sys::fs::OpenFlags Flags = (FileType == OFT_AssemblyFile) ? sys::fs::OF_Text |
| : sys::fs::OF_None; |
| std::unique_ptr<ToolOutputFile> Out = GetOutputStream(OutputFilename, Flags); |
| if (!Out) |
| return 1; |
| |
| std::unique_ptr<ToolOutputFile> DwoOut; |
| if (!SplitDwarfFile.empty()) { |
| if (FileType != OFT_ObjectFile) { |
| WithColor::error() << "dwo output only supported with object files\n"; |
| return 1; |
| } |
| DwoOut = GetOutputStream(SplitDwarfFile, sys::fs::OF_None); |
| if (!DwoOut) |
| return 1; |
| } |
| |
| std::unique_ptr<buffer_ostream> BOS; |
| raw_pwrite_stream *OS = &Out->os(); |
| std::unique_ptr<MCStreamer> Str; |
| |
| std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo()); |
| assert(MCII && "Unable to create instruction info!"); |
| |
| std::unique_ptr<MCSubtargetInfo> STI( |
| TheTarget->createMCSubtargetInfo(TripleName, MCPU, FeaturesStr)); |
| assert(STI && "Unable to create subtarget info!"); |
| |
| MCInstPrinter *IP = nullptr; |
| if (FileType == OFT_AssemblyFile) { |
| IP = TheTarget->createMCInstPrinter(Triple(TripleName), OutputAsmVariant, |
| *MAI, *MCII, *MRI); |
| |
| if (!IP) { |
| WithColor::error() |
| << "unable to create instruction printer for target triple '" |
| << TheTriple.normalize() << "' with assembly variant " |
| << OutputAsmVariant << ".\n"; |
| return 1; |
| } |
| |
| // Set the display preference for hex vs. decimal immediates. |
| IP->setPrintImmHex(PrintImmHex); |
| |
| // Set up the AsmStreamer. |
| std::unique_ptr<MCCodeEmitter> CE; |
| if (ShowEncoding) |
| CE.reset(TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx)); |
| |
| std::unique_ptr<MCAsmBackend> MAB( |
| TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions)); |
| auto FOut = std::make_unique<formatted_raw_ostream>(*OS); |
| Str.reset( |
| TheTarget->createAsmStreamer(Ctx, std::move(FOut), /*asmverbose*/ true, |
| /*useDwarfDirectory*/ true, IP, |
| std::move(CE), std::move(MAB), ShowInst)); |
| |
| } else if (FileType == OFT_Null) { |
| Str.reset(TheTarget->createNullStreamer(Ctx)); |
| } else { |
| assert(FileType == OFT_ObjectFile && "Invalid file type!"); |
| |
| if (!Out->os().supportsSeeking()) { |
| BOS = std::make_unique<buffer_ostream>(Out->os()); |
| OS = BOS.get(); |
| } |
| |
| MCCodeEmitter *CE = TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx); |
| MCAsmBackend *MAB = TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions); |
| Str.reset(TheTarget->createMCObjectStreamer( |
| TheTriple, Ctx, std::unique_ptr<MCAsmBackend>(MAB), |
| DwoOut ? MAB->createDwoObjectWriter(*OS, DwoOut->os()) |
| : MAB->createObjectWriter(*OS), |
| std::unique_ptr<MCCodeEmitter>(CE), *STI, MCOptions.MCRelaxAll, |
| MCOptions.MCIncrementalLinkerCompatible, |
| /*DWARFMustBeAtTheEnd*/ false)); |
| if (NoExecStack) |
| Str->InitSections(true); |
| } |
| |
| // Use Assembler information for parsing. |
| Str->setUseAssemblerInfoForParsing(true); |
| |
| int Res = 1; |
| bool disassemble = false; |
| switch (Action) { |
| case AC_AsLex: |
| Res = AsLexInput(SrcMgr, *MAI, Out->os()); |
| break; |
| case AC_Assemble: |
| Res = AssembleInput(ProgName, TheTarget, SrcMgr, Ctx, *Str, *MAI, *STI, |
| *MCII, MCOptions); |
| break; |
| case AC_MDisassemble: |
| assert(IP && "Expected assembly output"); |
| IP->setUseMarkup(true); |
| disassemble = true; |
| break; |
| case AC_Disassemble: |
| disassemble = true; |
| break; |
| } |
| if (disassemble) |
| Res = Disassembler::disassemble(*TheTarget, TripleName, *STI, *Str, *Buffer, |
| SrcMgr, Ctx, Out->os(), MCOptions); |
| |
| // Keep output if no errors. |
| if (Res == 0) { |
| Out->keep(); |
| if (DwoOut) |
| DwoOut->keep(); |
| } |
| return Res; |
| } |