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
GetTarget(const char * ProgName)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
GetOutputStream()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;
setDwarfDebugFlags(int argc,char ** argv)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;
setDwarfDebugProducer()238 static void setDwarfDebugProducer() {
239 if(!getenv("DEBUG_PRODUCER"))
240 return;
241 DwarfDebugProducer += getenv("DEBUG_PRODUCER");
242 }
243
AsLexInput(SourceMgr & SrcMgr,MCAsmInfo & MAI,raw_ostream & OS)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
fillCommandLineSymbols(MCAsmParser & Parser)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
AssembleInput(const char * ProgName,const Target * TheTarget,SourceMgr & SrcMgr,MCContext & Ctx,MCStreamer & Str,MCAsmInfo & MAI,MCSubtargetInfo & STI,MCInstrInfo & MCII,MCTargetOptions & MCOptions)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
main(int argc,char ** argv)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