1 //===-- llvm-mc.cpp - Machine Code Hacking Driver ---------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This utility is a simple driver that allows command line hacking on machine 11 // code. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "Disassembler.h" 16 #include "llvm/MC/MCAsmBackend.h" 17 #include "llvm/MC/MCAsmInfo.h" 18 #include "llvm/MC/MCContext.h" 19 #include "llvm/MC/MCInstPrinter.h" 20 #include "llvm/MC/MCInstrInfo.h" 21 #include "llvm/MC/MCObjectFileInfo.h" 22 #include "llvm/MC/MCParser/AsmLexer.h" 23 #include "llvm/MC/MCParser/MCTargetAsmParser.h" 24 #include "llvm/MC/MCRegisterInfo.h" 25 #include "llvm/MC/MCSectionMachO.h" 26 #include "llvm/MC/MCStreamer.h" 27 #include "llvm/MC/MCSubtargetInfo.h" 28 #include "llvm/MC/MCTargetOptionsCommandFlags.h" 29 #include "llvm/Support/CommandLine.h" 30 #include "llvm/Support/Compression.h" 31 #include "llvm/Support/FileUtilities.h" 32 #include "llvm/Support/FormattedStream.h" 33 #include "llvm/Support/Host.h" 34 #include "llvm/Support/ManagedStatic.h" 35 #include "llvm/Support/MemoryBuffer.h" 36 #include "llvm/Support/PrettyStackTrace.h" 37 #include "llvm/Support/Signals.h" 38 #include "llvm/Support/SourceMgr.h" 39 #include "llvm/Support/TargetRegistry.h" 40 #include "llvm/Support/TargetSelect.h" 41 #include "llvm/Support/ToolOutputFile.h" 42 43 using namespace llvm; 44 45 static cl::opt<std::string> 46 InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-")); 47 48 static cl::opt<std::string> 49 OutputFilename("o", cl::desc("Output filename"), 50 cl::value_desc("filename")); 51 52 static cl::opt<bool> 53 ShowEncoding("show-encoding", cl::desc("Show instruction encodings")); 54 55 static cl::opt<bool> RelaxELFRel( 56 "relax-relocations", cl::init(true), 57 cl::desc("Emit R_X86_64_GOTPCRELX instead of R_X86_64_GOTPCREL")); 58 59 static cl::opt<DebugCompressionType> 60 CompressDebugSections("compress-debug-sections", cl::ValueOptional, 61 cl::init(DebugCompressionType::DCT_None), 62 cl::desc("Choose DWARF debug sections compression:"), 63 cl::values( 64 clEnumValN(DebugCompressionType::DCT_None, "none", 65 "No compression"), 66 clEnumValN(DebugCompressionType::DCT_Zlib, "zlib", 67 "Use zlib compression"), 68 clEnumValN(DebugCompressionType::DCT_ZlibGnu, "zlib-gnu", 69 "Use zlib-gnu compression (depricated)"), 70 clEnumValEnd)); 71 72 static cl::opt<bool> 73 ShowInst("show-inst", cl::desc("Show internal instruction representation")); 74 75 static cl::opt<bool> 76 ShowInstOperands("show-inst-operands", 77 cl::desc("Show instructions operands as parsed")); 78 79 static cl::opt<unsigned> 80 OutputAsmVariant("output-asm-variant", 81 cl::desc("Syntax variant to use for output printing")); 82 83 static cl::opt<bool> 84 PrintImmHex("print-imm-hex", cl::init(false), 85 cl::desc("Prefer hex format for immediate values")); 86 87 static cl::list<std::string> 88 DefineSymbol("defsym", cl::desc("Defines a symbol to be an integer constant")); 89 90 static cl::opt<bool> 91 PreserveComments("preserve-comments", 92 cl::desc("Preserve Comments in outputted assembly")); 93 94 enum OutputFileType { 95 OFT_Null, 96 OFT_AssemblyFile, 97 OFT_ObjectFile 98 }; 99 static cl::opt<OutputFileType> 100 FileType("filetype", cl::init(OFT_AssemblyFile), 101 cl::desc("Choose an output file type:"), 102 cl::values( 103 clEnumValN(OFT_AssemblyFile, "asm", 104 "Emit an assembly ('.s') file"), 105 clEnumValN(OFT_Null, "null", 106 "Don't emit anything (for timing purposes)"), 107 clEnumValN(OFT_ObjectFile, "obj", 108 "Emit a native object ('.o') file"), 109 clEnumValEnd)); 110 111 static cl::list<std::string> 112 IncludeDirs("I", cl::desc("Directory of include files"), 113 cl::value_desc("directory"), cl::Prefix); 114 115 static cl::opt<std::string> 116 ArchName("arch", cl::desc("Target arch to assemble for, " 117 "see -version for available targets")); 118 119 static cl::opt<std::string> 120 TripleName("triple", cl::desc("Target triple to assemble for, " 121 "see -version for available targets")); 122 123 static cl::opt<std::string> 124 MCPU("mcpu", 125 cl::desc("Target a specific cpu type (-mcpu=help for details)"), 126 cl::value_desc("cpu-name"), 127 cl::init("")); 128 129 static cl::list<std::string> 130 MAttrs("mattr", 131 cl::CommaSeparated, 132 cl::desc("Target specific attributes (-mattr=help for details)"), 133 cl::value_desc("a1,+a2,-a3,...")); 134 135 static cl::opt<bool> PIC("position-independent", 136 cl::desc("Position independent"), cl::init(false)); 137 138 static cl::opt<llvm::CodeModel::Model> 139 CMModel("code-model", 140 cl::desc("Choose code model"), 141 cl::init(CodeModel::Default), 142 cl::values(clEnumValN(CodeModel::Default, "default", 143 "Target default code model"), 144 clEnumValN(CodeModel::Small, "small", 145 "Small code model"), 146 clEnumValN(CodeModel::Kernel, "kernel", 147 "Kernel code model"), 148 clEnumValN(CodeModel::Medium, "medium", 149 "Medium code model"), 150 clEnumValN(CodeModel::Large, "large", 151 "Large code model"), 152 clEnumValEnd)); 153 154 static cl::opt<bool> 155 NoInitialTextSection("n", cl::desc("Don't assume assembly file starts " 156 "in the text section")); 157 158 static cl::opt<bool> 159 GenDwarfForAssembly("g", cl::desc("Generate dwarf debugging info for assembly " 160 "source files")); 161 162 static cl::opt<std::string> 163 DebugCompilationDir("fdebug-compilation-dir", 164 cl::desc("Specifies the debug info's compilation dir")); 165 166 static cl::opt<std::string> 167 MainFileName("main-file-name", 168 cl::desc("Specifies the name we should consider the input file")); 169 170 static cl::opt<bool> SaveTempLabels("save-temp-labels", 171 cl::desc("Don't discard temporary labels")); 172 173 static cl::opt<bool> NoExecStack("no-exec-stack", 174 cl::desc("File doesn't need an exec stack")); 175 176 enum ActionType { 177 AC_AsLex, 178 AC_Assemble, 179 AC_Disassemble, 180 AC_MDisassemble, 181 }; 182 183 static cl::opt<ActionType> 184 Action(cl::desc("Action to perform:"), 185 cl::init(AC_Assemble), 186 cl::values(clEnumValN(AC_AsLex, "as-lex", 187 "Lex tokens from a .s file"), 188 clEnumValN(AC_Assemble, "assemble", 189 "Assemble a .s file (default)"), 190 clEnumValN(AC_Disassemble, "disassemble", 191 "Disassemble strings of hex bytes"), 192 clEnumValN(AC_MDisassemble, "mdis", 193 "Marked up disassembly of strings of hex bytes"), 194 clEnumValEnd)); 195 196 static const Target *GetTarget(const char *ProgName) { 197 // Figure out the target triple. 198 if (TripleName.empty()) 199 TripleName = sys::getDefaultTargetTriple(); 200 Triple TheTriple(Triple::normalize(TripleName)); 201 202 // Get the target specific parser. 203 std::string Error; 204 const Target *TheTarget = TargetRegistry::lookupTarget(ArchName, TheTriple, 205 Error); 206 if (!TheTarget) { 207 errs() << ProgName << ": " << Error; 208 return nullptr; 209 } 210 211 // Update the triple name and return the found target. 212 TripleName = TheTriple.getTriple(); 213 return TheTarget; 214 } 215 216 static std::unique_ptr<tool_output_file> GetOutputStream() { 217 if (OutputFilename == "") 218 OutputFilename = "-"; 219 220 std::error_code EC; 221 auto Out = llvm::make_unique<tool_output_file>(OutputFilename, EC, 222 sys::fs::F_None); 223 if (EC) { 224 errs() << EC.message() << '\n'; 225 return nullptr; 226 } 227 228 return Out; 229 } 230 231 static std::string DwarfDebugFlags; 232 static void setDwarfDebugFlags(int argc, char **argv) { 233 if (!getenv("RC_DEBUG_OPTIONS")) 234 return; 235 for (int i = 0; i < argc; i++) { 236 DwarfDebugFlags += argv[i]; 237 if (i + 1 < argc) 238 DwarfDebugFlags += " "; 239 } 240 } 241 242 static std::string DwarfDebugProducer; 243 static void setDwarfDebugProducer() { 244 if(!getenv("DEBUG_PRODUCER")) 245 return; 246 DwarfDebugProducer += getenv("DEBUG_PRODUCER"); 247 } 248 249 static int AsLexInput(SourceMgr &SrcMgr, MCAsmInfo &MAI, 250 raw_ostream &OS) { 251 252 AsmLexer Lexer(MAI); 253 Lexer.setBuffer(SrcMgr.getMemoryBuffer(SrcMgr.getMainFileID())->getBuffer()); 254 255 bool Error = false; 256 while (Lexer.Lex().isNot(AsmToken::Eof)) { 257 const AsmToken &Tok = Lexer.getTok(); 258 259 switch (Tok.getKind()) { 260 default: 261 SrcMgr.PrintMessage(Lexer.getLoc(), SourceMgr::DK_Warning, 262 "unknown token"); 263 Error = true; 264 break; 265 case AsmToken::Error: 266 Error = true; // error already printed. 267 break; 268 case AsmToken::Identifier: 269 OS << "identifier: " << Lexer.getTok().getString(); 270 break; 271 case AsmToken::Integer: 272 OS << "int: " << Lexer.getTok().getString(); 273 break; 274 case AsmToken::Real: 275 OS << "real: " << Lexer.getTok().getString(); 276 break; 277 case AsmToken::String: 278 OS << "string: " << Lexer.getTok().getString(); 279 break; 280 281 case AsmToken::Amp: OS << "Amp"; break; 282 case AsmToken::AmpAmp: OS << "AmpAmp"; break; 283 case AsmToken::At: OS << "At"; break; 284 case AsmToken::Caret: OS << "Caret"; break; 285 case AsmToken::Colon: OS << "Colon"; break; 286 case AsmToken::Comma: OS << "Comma"; break; 287 case AsmToken::Dollar: OS << "Dollar"; break; 288 case AsmToken::Dot: OS << "Dot"; break; 289 case AsmToken::EndOfStatement: OS << "EndOfStatement"; break; 290 case AsmToken::Eof: OS << "Eof"; break; 291 case AsmToken::Equal: OS << "Equal"; break; 292 case AsmToken::EqualEqual: OS << "EqualEqual"; break; 293 case AsmToken::Exclaim: OS << "Exclaim"; break; 294 case AsmToken::ExclaimEqual: OS << "ExclaimEqual"; break; 295 case AsmToken::Greater: OS << "Greater"; break; 296 case AsmToken::GreaterEqual: OS << "GreaterEqual"; break; 297 case AsmToken::GreaterGreater: OS << "GreaterGreater"; break; 298 case AsmToken::Hash: OS << "Hash"; break; 299 case AsmToken::LBrac: OS << "LBrac"; break; 300 case AsmToken::LCurly: OS << "LCurly"; break; 301 case AsmToken::LParen: OS << "LParen"; break; 302 case AsmToken::Less: OS << "Less"; break; 303 case AsmToken::LessEqual: OS << "LessEqual"; break; 304 case AsmToken::LessGreater: OS << "LessGreater"; break; 305 case AsmToken::LessLess: OS << "LessLess"; break; 306 case AsmToken::Minus: OS << "Minus"; break; 307 case AsmToken::Percent: OS << "Percent"; break; 308 case AsmToken::Pipe: OS << "Pipe"; break; 309 case AsmToken::PipePipe: OS << "PipePipe"; break; 310 case AsmToken::Plus: OS << "Plus"; break; 311 case AsmToken::RBrac: OS << "RBrac"; break; 312 case AsmToken::RCurly: OS << "RCurly"; break; 313 case AsmToken::RParen: OS << "RParen"; break; 314 case AsmToken::Slash: OS << "Slash"; break; 315 case AsmToken::Star: OS << "Star"; break; 316 case AsmToken::Tilde: OS << "Tilde"; break; 317 } 318 319 // Print the token string. 320 OS << " (\""; 321 OS.write_escaped(Tok.getString()); 322 OS << "\")\n"; 323 } 324 325 return Error; 326 } 327 328 static int fillCommandLineSymbols(MCAsmParser &Parser){ 329 for(auto &I: DefineSymbol){ 330 auto Pair = StringRef(I).split('='); 331 if(Pair.second.empty()){ 332 errs() << "error: defsym must be of the form: sym=value: " << I; 333 return 1; 334 } 335 int64_t Value; 336 if(Pair.second.getAsInteger(0, Value)){ 337 errs() << "error: Value is not an integer: " << Pair.second; 338 return 1; 339 } 340 auto &Context = Parser.getContext(); 341 auto Symbol = Context.getOrCreateSymbol(Pair.first); 342 Parser.getStreamer().EmitAssignment(Symbol, 343 MCConstantExpr::create(Value, Context)); 344 } 345 return 0; 346 } 347 348 static int AssembleInput(const char *ProgName, const Target *TheTarget, 349 SourceMgr &SrcMgr, MCContext &Ctx, MCStreamer &Str, 350 MCAsmInfo &MAI, MCSubtargetInfo &STI, 351 MCInstrInfo &MCII, MCTargetOptions &MCOptions) { 352 std::unique_ptr<MCAsmParser> Parser( 353 createMCAsmParser(SrcMgr, Ctx, Str, MAI)); 354 std::unique_ptr<MCTargetAsmParser> TAP( 355 TheTarget->createMCAsmParser(STI, *Parser, MCII, MCOptions)); 356 357 if (!TAP) { 358 errs() << ProgName 359 << ": error: this target does not support assembly parsing.\n"; 360 return 1; 361 } 362 363 int SymbolResult = fillCommandLineSymbols(*Parser); 364 if(SymbolResult) 365 return SymbolResult; 366 Parser->setShowParsedOperands(ShowInstOperands); 367 Parser->setTargetParser(*TAP); 368 369 int Res = Parser->Run(NoInitialTextSection); 370 371 return Res; 372 } 373 374 int main(int argc, char **argv) { 375 // Print a stack trace if we signal out. 376 sys::PrintStackTraceOnErrorSignal(argv[0]); 377 PrettyStackTraceProgram X(argc, argv); 378 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit. 379 380 // Initialize targets and assembly printers/parsers. 381 llvm::InitializeAllTargetInfos(); 382 llvm::InitializeAllTargetMCs(); 383 llvm::InitializeAllAsmParsers(); 384 llvm::InitializeAllDisassemblers(); 385 386 // Register the target printer for --version. 387 cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion); 388 389 cl::ParseCommandLineOptions(argc, argv, "llvm machine code playground\n"); 390 MCTargetOptions MCOptions = InitMCTargetOptionsFromFlags(); 391 TripleName = Triple::normalize(TripleName); 392 setDwarfDebugFlags(argc, argv); 393 394 setDwarfDebugProducer(); 395 396 const char *ProgName = argv[0]; 397 const Target *TheTarget = GetTarget(ProgName); 398 if (!TheTarget) 399 return 1; 400 // Now that GetTarget() has (potentially) replaced TripleName, it's safe to 401 // construct the Triple object. 402 Triple TheTriple(TripleName); 403 404 ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr = 405 MemoryBuffer::getFileOrSTDIN(InputFilename); 406 if (std::error_code EC = BufferPtr.getError()) { 407 errs() << InputFilename << ": " << EC.message() << '\n'; 408 return 1; 409 } 410 MemoryBuffer *Buffer = BufferPtr->get(); 411 412 SourceMgr SrcMgr; 413 414 // Tell SrcMgr about this buffer, which is what the parser will pick up. 415 SrcMgr.AddNewSourceBuffer(std::move(*BufferPtr), SMLoc()); 416 417 // Record the location of the include directories so that the lexer can find 418 // it later. 419 SrcMgr.setIncludeDirs(IncludeDirs); 420 421 std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName)); 422 assert(MRI && "Unable to create target register info!"); 423 424 std::unique_ptr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, TripleName)); 425 assert(MAI && "Unable to create target asm info!"); 426 427 MAI->setRelaxELFRelocations(RelaxELFRel); 428 429 if (CompressDebugSections != DebugCompressionType::DCT_None) { 430 if (!zlib::isAvailable()) { 431 errs() << ProgName 432 << ": build tools with zlib to enable -compress-debug-sections"; 433 return 1; 434 } 435 MAI->setCompressDebugSections(CompressDebugSections); 436 } 437 MAI->setPreserveAsmComments(PreserveComments); 438 439 // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and 440 // MCObjectFileInfo needs a MCContext reference in order to initialize itself. 441 MCObjectFileInfo MOFI; 442 MCContext Ctx(MAI.get(), MRI.get(), &MOFI, &SrcMgr); 443 MOFI.InitMCObjectFileInfo(TheTriple, PIC, CMModel, Ctx); 444 445 if (SaveTempLabels) 446 Ctx.setAllowTemporaryLabels(false); 447 448 Ctx.setGenDwarfForAssembly(GenDwarfForAssembly); 449 // Default to 4 for dwarf version. 450 unsigned DwarfVersion = MCOptions.DwarfVersion ? MCOptions.DwarfVersion : 4; 451 if (DwarfVersion < 2 || DwarfVersion > 4) { 452 errs() << ProgName << ": Dwarf version " << DwarfVersion 453 << " is not supported." << '\n'; 454 return 1; 455 } 456 Ctx.setDwarfVersion(DwarfVersion); 457 if (!DwarfDebugFlags.empty()) 458 Ctx.setDwarfDebugFlags(StringRef(DwarfDebugFlags)); 459 if (!DwarfDebugProducer.empty()) 460 Ctx.setDwarfDebugProducer(StringRef(DwarfDebugProducer)); 461 if (!DebugCompilationDir.empty()) 462 Ctx.setCompilationDir(DebugCompilationDir); 463 else { 464 // If no compilation dir is set, try to use the current directory. 465 SmallString<128> CWD; 466 if (!sys::fs::current_path(CWD)) 467 Ctx.setCompilationDir(CWD); 468 } 469 if (!MainFileName.empty()) 470 Ctx.setMainFileName(MainFileName); 471 472 // Package up features to be passed to target/subtarget 473 std::string FeaturesStr; 474 if (MAttrs.size()) { 475 SubtargetFeatures Features; 476 for (unsigned i = 0; i != MAttrs.size(); ++i) 477 Features.AddFeature(MAttrs[i]); 478 FeaturesStr = Features.getString(); 479 } 480 481 std::unique_ptr<tool_output_file> Out = GetOutputStream(); 482 if (!Out) 483 return 1; 484 485 std::unique_ptr<buffer_ostream> BOS; 486 raw_pwrite_stream *OS = &Out->os(); 487 std::unique_ptr<MCStreamer> Str; 488 489 std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo()); 490 std::unique_ptr<MCSubtargetInfo> STI( 491 TheTarget->createMCSubtargetInfo(TripleName, MCPU, FeaturesStr)); 492 493 MCInstPrinter *IP = nullptr; 494 if (FileType == OFT_AssemblyFile) { 495 IP = TheTarget->createMCInstPrinter(Triple(TripleName), OutputAsmVariant, 496 *MAI, *MCII, *MRI); 497 498 // Set the display preference for hex vs. decimal immediates. 499 IP->setPrintImmHex(PrintImmHex); 500 501 // Set up the AsmStreamer. 502 MCCodeEmitter *CE = nullptr; 503 MCAsmBackend *MAB = nullptr; 504 if (ShowEncoding) { 505 CE = TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx); 506 MAB = TheTarget->createMCAsmBackend(*MRI, TripleName, MCPU); 507 } 508 auto FOut = llvm::make_unique<formatted_raw_ostream>(*OS); 509 Str.reset(TheTarget->createAsmStreamer( 510 Ctx, std::move(FOut), /*asmverbose*/ true, 511 /*useDwarfDirectory*/ true, IP, CE, MAB, ShowInst)); 512 513 } else if (FileType == OFT_Null) { 514 Str.reset(TheTarget->createNullStreamer(Ctx)); 515 } else { 516 assert(FileType == OFT_ObjectFile && "Invalid file type!"); 517 518 // Don't waste memory on names of temp labels. 519 Ctx.setUseNamesOnTempLabels(false); 520 521 if (!Out->os().supportsSeeking()) { 522 BOS = make_unique<buffer_ostream>(Out->os()); 523 OS = BOS.get(); 524 } 525 526 MCCodeEmitter *CE = TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx); 527 MCAsmBackend *MAB = TheTarget->createMCAsmBackend(*MRI, TripleName, MCPU); 528 Str.reset(TheTarget->createMCObjectStreamer( 529 TheTriple, Ctx, *MAB, *OS, CE, *STI, MCOptions.MCRelaxAll, 530 MCOptions.MCIncrementalLinkerCompatible, 531 /*DWARFMustBeAtTheEnd*/ false)); 532 if (NoExecStack) 533 Str->InitSections(true); 534 } 535 536 int Res = 1; 537 bool disassemble = false; 538 switch (Action) { 539 case AC_AsLex: 540 Res = AsLexInput(SrcMgr, *MAI, Out->os()); 541 break; 542 case AC_Assemble: 543 Res = AssembleInput(ProgName, TheTarget, SrcMgr, Ctx, *Str, *MAI, *STI, 544 *MCII, MCOptions); 545 break; 546 case AC_MDisassemble: 547 assert(IP && "Expected assembly output"); 548 IP->setUseMarkup(1); 549 disassemble = true; 550 break; 551 case AC_Disassemble: 552 disassemble = true; 553 break; 554 } 555 if (disassemble) 556 Res = Disassembler::disassemble(*TheTarget, TripleName, *STI, *Str, 557 *Buffer, SrcMgr, Out->os()); 558 559 // Keep output if no errors. 560 if (Res == 0) Out->keep(); 561 return Res; 562 } 563
