1 //===-- llvm-mc.cpp - Machine Code Hacking Driver ---------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This utility is a simple driver that allows command line hacking on machine
12 //===----------------------------------------------------------------------===//
14 #include "Disassembler.h"
15 #include "llvm/MC/MCAsmBackend.h"
16 #include "llvm/MC/MCAsmInfo.h"
17 #include "llvm/MC/MCCodeEmitter.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/MCObjectWriter.h"
23 #include "llvm/MC/MCParser/AsmLexer.h"
24 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
25 #include "llvm/MC/MCRegisterInfo.h"
26 #include "llvm/MC/MCStreamer.h"
27 #include "llvm/MC/MCSubtargetInfo.h"
28 #include "llvm/MC/MCTargetOptionsCommandFlags.inc"
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/InitLLVM.h"
35 #include "llvm/Support/MemoryBuffer.h"
36 #include "llvm/Support/SourceMgr.h"
37 #include "llvm/Support/TargetRegistry.h"
38 #include "llvm/Support/TargetSelect.h"
39 #include "llvm/Support/ToolOutputFile.h"
40 #include "llvm/Support/WithColor.h"
44 static cl::opt<std::string>
45 InputFilename(cl::Positional, cl::desc("<input file>"), cl::init("-"));
47 static cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
48 cl::value_desc("filename"),
51 static cl::opt<std::string> SplitDwarfFile("split-dwarf-file",
52 cl::desc("DWO output filename"),
53 cl::value_desc("filename"));
56 ShowEncoding("show-encoding", cl::desc("Show instruction encodings"));
58 static cl::opt<bool> RelaxELFRel(
59 "relax-relocations", cl::init(true),
60 cl::desc("Emit R_X86_64_GOTPCRELX instead of R_X86_64_GOTPCREL"));
62 static cl::opt<DebugCompressionType> CompressDebugSections(
63 "compress-debug-sections", cl::ValueOptional,
64 cl::init(DebugCompressionType::None),
65 cl::desc("Choose DWARF debug sections compression:"),
66 cl::values(clEnumValN(DebugCompressionType::None, "none", "No compression"),
67 clEnumValN(DebugCompressionType::Z, "zlib",
68 "Use zlib compression"),
69 clEnumValN(DebugCompressionType::GNU, "zlib-gnu",
70 "Use zlib-gnu compression (deprecated)")));
73 ShowInst("show-inst", cl::desc("Show internal instruction representation"));
76 ShowInstOperands("show-inst-operands",
77 cl::desc("Show instructions operands as parsed"));
79 static cl::opt<unsigned>
80 OutputAsmVariant("output-asm-variant",
81 cl::desc("Syntax variant to use for output printing"));
84 PrintImmHex("print-imm-hex", cl::init(false),
85 cl::desc("Prefer hex format for immediate values"));
87 static cl::list<std::string>
88 DefineSymbol("defsym", cl::desc("Defines a symbol to be an integer constant"));
91 PreserveComments("preserve-comments",
92 cl::desc("Preserve Comments in outputted assembly"));
99 static cl::opt<OutputFileType>
100 FileType("filetype", cl::init(OFT_AssemblyFile),
101 cl::desc("Choose an output file type:"),
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")));
110 static cl::list<std::string>
111 IncludeDirs("I", cl::desc("Directory of include files"),
112 cl::value_desc("directory"), cl::Prefix);
114 static cl::opt<std::string>
115 ArchName("arch", cl::desc("Target arch to assemble for, "
116 "see -version for available targets"));
118 static cl::opt<std::string>
119 TripleName("triple", cl::desc("Target triple to assemble for, "
120 "see -version for available targets"));
122 static cl::opt<std::string>
124 cl::desc("Target a specific cpu type (-mcpu=help for details)"),
125 cl::value_desc("cpu-name"),
128 static cl::list<std::string>
131 cl::desc("Target specific attributes (-mattr=help for details)"),
132 cl::value_desc("a1,+a2,-a3,..."));
134 static cl::opt<bool> PIC("position-independent",
135 cl::desc("Position independent"), cl::init(false));
138 LargeCodeModel("large-code-model",
139 cl::desc("Create cfi directives that assume the code might "
140 "be more than 2gb away"));
143 NoInitialTextSection("n", cl::desc("Don't assume assembly file starts "
144 "in the text section"));
147 GenDwarfForAssembly("g", cl::desc("Generate dwarf debugging info for assembly "
150 static cl::opt<std::string>
151 DebugCompilationDir("fdebug-compilation-dir",
152 cl::desc("Specifies the debug info's compilation dir"));
154 static cl::list<std::string>
155 DebugPrefixMap("fdebug-prefix-map",
156 cl::desc("Map file source paths in debug info"),
157 cl::value_desc("= separated key-value pairs"));
159 static cl::opt<std::string>
160 MainFileName("main-file-name",
161 cl::desc("Specifies the name we should consider the input file"));
163 static cl::opt<bool> SaveTempLabels("save-temp-labels",
164 cl::desc("Don't discard temporary labels"));
166 static cl::opt<bool> LexMasmIntegers(
168 cl::desc("Enable binary and hex masm integers (0b110 and 0ABCh)"));
170 static cl::opt<bool> NoExecStack("no-exec-stack",
171 cl::desc("File doesn't need an exec stack"));
180 static cl::opt<ActionType>
181 Action(cl::desc("Action to perform:"),
182 cl::init(AC_Assemble),
183 cl::values(clEnumValN(AC_AsLex, "as-lex",
184 "Lex tokens from a .s file"),
185 clEnumValN(AC_Assemble, "assemble",
186 "Assemble a .s file (default)"),
187 clEnumValN(AC_Disassemble, "disassemble",
188 "Disassemble strings of hex bytes"),
189 clEnumValN(AC_MDisassemble, "mdis",
190 "Marked up disassembly of strings of hex bytes")));
192 static const Target *GetTarget(const char *ProgName) {
193 // Figure out the target triple.
194 if (TripleName.empty())
195 TripleName = sys::getDefaultTargetTriple();
196 Triple TheTriple(Triple::normalize(TripleName));
198 // Get the target specific parser.
200 const Target *TheTarget = TargetRegistry::lookupTarget(ArchName, TheTriple,
203 WithColor::error(errs(), ProgName) << Error;
207 // Update the triple name and return the found target.
208 TripleName = TheTriple.getTriple();
212 static std::unique_ptr<ToolOutputFile> GetOutputStream(StringRef Path,
213 sys::fs::OpenFlags Flags) {
215 auto Out = std::make_unique<ToolOutputFile>(Path, EC, Flags);
217 WithColor::error() << EC.message() << '\n';
224 static std::string DwarfDebugFlags;
225 static void setDwarfDebugFlags(int argc, char **argv) {
226 if (!getenv("RC_DEBUG_OPTIONS"))
228 for (int i = 0; i < argc; i++) {
229 DwarfDebugFlags += argv[i];
231 DwarfDebugFlags += " ";
235 static std::string DwarfDebugProducer;
236 static void setDwarfDebugProducer() {
237 if(!getenv("DEBUG_PRODUCER"))
239 DwarfDebugProducer += getenv("DEBUG_PRODUCER");
242 static int AsLexInput(SourceMgr &SrcMgr, MCAsmInfo &MAI,
246 Lexer.setBuffer(SrcMgr.getMemoryBuffer(SrcMgr.getMainFileID())->getBuffer());
249 while (Lexer.Lex().isNot(AsmToken::Eof)) {
250 Lexer.getTok().dump(OS);
252 if (Lexer.getTok().getKind() == AsmToken::Error)
259 static int fillCommandLineSymbols(MCAsmParser &Parser) {
260 for (auto &I: DefineSymbol) {
261 auto Pair = StringRef(I).split('=');
262 auto Sym = Pair.first;
263 auto Val = Pair.second;
265 if (Sym.empty() || Val.empty()) {
266 WithColor::error() << "defsym must be of the form: sym=value: " << I
271 if (Val.getAsInteger(0, Value)) {
272 WithColor::error() << "value is not an integer: " << Val << "\n";
275 Parser.getContext().setSymbolValue(Parser.getStreamer(), Sym, Value);
280 static int AssembleInput(const char *ProgName, const Target *TheTarget,
281 SourceMgr &SrcMgr, MCContext &Ctx, MCStreamer &Str,
282 MCAsmInfo &MAI, MCSubtargetInfo &STI,
283 MCInstrInfo &MCII, MCTargetOptions const &MCOptions) {
284 std::unique_ptr<MCAsmParser> Parser(
285 createMCAsmParser(SrcMgr, Ctx, Str, MAI));
286 std::unique_ptr<MCTargetAsmParser> TAP(
287 TheTarget->createMCAsmParser(STI, *Parser, MCII, MCOptions));
290 WithColor::error(errs(), ProgName)
291 << "this target does not support assembly parsing.\n";
295 int SymbolResult = fillCommandLineSymbols(*Parser);
298 Parser->setShowParsedOperands(ShowInstOperands);
299 Parser->setTargetParser(*TAP);
300 Parser->getLexer().setLexMasmIntegers(LexMasmIntegers);
302 int Res = Parser->Run(NoInitialTextSection);
307 int main(int argc, char **argv) {
308 InitLLVM X(argc, argv);
310 // Initialize targets and assembly printers/parsers.
311 llvm::InitializeAllTargetInfos();
312 llvm::InitializeAllTargetMCs();
313 llvm::InitializeAllAsmParsers();
314 llvm::InitializeAllDisassemblers();
316 // Register the target printer for --version.
317 cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
319 cl::ParseCommandLineOptions(argc, argv, "llvm machine code playground\n");
320 const MCTargetOptions MCOptions = InitMCTargetOptionsFromFlags();
321 setDwarfDebugFlags(argc, argv);
323 setDwarfDebugProducer();
325 const char *ProgName = argv[0];
326 const Target *TheTarget = GetTarget(ProgName);
329 // Now that GetTarget() has (potentially) replaced TripleName, it's safe to
330 // construct the Triple object.
331 Triple TheTriple(TripleName);
333 ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr =
334 MemoryBuffer::getFileOrSTDIN(InputFilename);
335 if (std::error_code EC = BufferPtr.getError()) {
336 WithColor::error(errs(), ProgName)
337 << InputFilename << ": " << EC.message() << '\n';
340 MemoryBuffer *Buffer = BufferPtr->get();
344 // Tell SrcMgr about this buffer, which is what the parser will pick up.
345 SrcMgr.AddNewSourceBuffer(std::move(*BufferPtr), SMLoc());
347 // Record the location of the include directories so that the lexer can find
349 SrcMgr.setIncludeDirs(IncludeDirs);
351 std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
352 assert(MRI && "Unable to create target register info!");
354 std::unique_ptr<MCAsmInfo> MAI(
355 TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
356 assert(MAI && "Unable to create target asm info!");
358 MAI->setRelaxELFRelocations(RelaxELFRel);
360 if (CompressDebugSections != DebugCompressionType::None) {
361 if (!zlib::isAvailable()) {
362 WithColor::error(errs(), ProgName)
363 << "build tools with zlib to enable -compress-debug-sections";
366 MAI->setCompressDebugSections(CompressDebugSections);
368 MAI->setPreserveAsmComments(PreserveComments);
370 // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
371 // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
372 MCObjectFileInfo MOFI;
373 MCContext Ctx(MAI.get(), MRI.get(), &MOFI, &SrcMgr, &MCOptions);
374 MOFI.InitMCObjectFileInfo(TheTriple, PIC, Ctx, LargeCodeModel);
377 Ctx.setAllowTemporaryLabels(false);
379 Ctx.setGenDwarfForAssembly(GenDwarfForAssembly);
380 // Default to 4 for dwarf version.
381 unsigned DwarfVersion = MCOptions.DwarfVersion ? MCOptions.DwarfVersion : 4;
382 if (DwarfVersion < 2 || DwarfVersion > 5) {
383 errs() << ProgName << ": Dwarf version " << DwarfVersion
384 << " is not supported." << '\n';
387 Ctx.setDwarfVersion(DwarfVersion);
388 if (!DwarfDebugFlags.empty())
389 Ctx.setDwarfDebugFlags(StringRef(DwarfDebugFlags));
390 if (!DwarfDebugProducer.empty())
391 Ctx.setDwarfDebugProducer(StringRef(DwarfDebugProducer));
392 if (!DebugCompilationDir.empty())
393 Ctx.setCompilationDir(DebugCompilationDir);
395 // If no compilation dir is set, try to use the current directory.
396 SmallString<128> CWD;
397 if (!sys::fs::current_path(CWD))
398 Ctx.setCompilationDir(CWD);
400 for (const auto &Arg : DebugPrefixMap) {
401 const auto &KV = StringRef(Arg).split('=');
402 Ctx.addDebugPrefixMapEntry(KV.first, KV.second);
404 if (!MainFileName.empty())
405 Ctx.setMainFileName(MainFileName);
406 if (GenDwarfForAssembly)
407 Ctx.setGenDwarfRootFile(InputFilename, Buffer->getBuffer());
409 // Package up features to be passed to target/subtarget
410 std::string FeaturesStr;
412 SubtargetFeatures Features;
413 for (unsigned i = 0; i != MAttrs.size(); ++i)
414 Features.AddFeature(MAttrs[i]);
415 FeaturesStr = Features.getString();
418 sys::fs::OpenFlags Flags = (FileType == OFT_AssemblyFile) ? sys::fs::OF_Text
420 std::unique_ptr<ToolOutputFile> Out = GetOutputStream(OutputFilename, Flags);
424 std::unique_ptr<ToolOutputFile> DwoOut;
425 if (!SplitDwarfFile.empty()) {
426 if (FileType != OFT_ObjectFile) {
427 WithColor::error() << "dwo output only supported with object files\n";
430 DwoOut = GetOutputStream(SplitDwarfFile, sys::fs::OF_None);
435 std::unique_ptr<buffer_ostream> BOS;
436 raw_pwrite_stream *OS = &Out->os();
437 std::unique_ptr<MCStreamer> Str;
439 std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
440 std::unique_ptr<MCSubtargetInfo> STI(
441 TheTarget->createMCSubtargetInfo(TripleName, MCPU, FeaturesStr));
443 MCInstPrinter *IP = nullptr;
444 if (FileType == OFT_AssemblyFile) {
445 IP = TheTarget->createMCInstPrinter(Triple(TripleName), OutputAsmVariant,
450 << "unable to create instruction printer for target triple '"
451 << TheTriple.normalize() << "' with assembly variant "
452 << OutputAsmVariant << ".\n";
456 // Set the display preference for hex vs. decimal immediates.
457 IP->setPrintImmHex(PrintImmHex);
459 // Set up the AsmStreamer.
460 std::unique_ptr<MCCodeEmitter> CE;
462 CE.reset(TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx));
464 std::unique_ptr<MCAsmBackend> MAB(
465 TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
466 auto FOut = std::make_unique<formatted_raw_ostream>(*OS);
468 TheTarget->createAsmStreamer(Ctx, std::move(FOut), /*asmverbose*/ true,
469 /*useDwarfDirectory*/ true, IP,
470 std::move(CE), std::move(MAB), ShowInst));
472 } else if (FileType == OFT_Null) {
473 Str.reset(TheTarget->createNullStreamer(Ctx));
475 assert(FileType == OFT_ObjectFile && "Invalid file type!");
477 // Don't waste memory on names of temp labels.
478 Ctx.setUseNamesOnTempLabels(false);
480 if (!Out->os().supportsSeeking()) {
481 BOS = std::make_unique<buffer_ostream>(Out->os());
485 MCCodeEmitter *CE = TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx);
486 MCAsmBackend *MAB = TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions);
487 Str.reset(TheTarget->createMCObjectStreamer(
488 TheTriple, Ctx, std::unique_ptr<MCAsmBackend>(MAB),
489 DwoOut ? MAB->createDwoObjectWriter(*OS, DwoOut->os())
490 : MAB->createObjectWriter(*OS),
491 std::unique_ptr<MCCodeEmitter>(CE), *STI, MCOptions.MCRelaxAll,
492 MCOptions.MCIncrementalLinkerCompatible,
493 /*DWARFMustBeAtTheEnd*/ false));
495 Str->InitSections(true);
498 // Use Assembler information for parsing.
499 Str->setUseAssemblerInfoForParsing(true);
502 bool disassemble = false;
505 Res = AsLexInput(SrcMgr, *MAI, Out->os());
508 Res = AssembleInput(ProgName, TheTarget, SrcMgr, Ctx, *Str, *MAI, *STI,
511 case AC_MDisassemble:
512 assert(IP && "Expected assembly output");
513 IP->setUseMarkup(true);
521 Res = Disassembler::disassemble(*TheTarget, TripleName, *STI, *Str, *Buffer,
522 SrcMgr, Ctx, Out->os(), MCOptions);
524 // Keep output if no errors.