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