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