1 //===-- llvm-mc.cpp - Machine Code Hacking Driver ---------------*- C++ -*-===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This utility is a simple driver that allows command line hacking on machine
10 // code.
11 //
12 //===----------------------------------------------------------------------===//
13 
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.h"
29 #include "llvm/MC/TargetRegistry.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/Compression.h"
32 #include "llvm/Support/FileUtilities.h"
33 #include "llvm/Support/FormattedStream.h"
34 #include "llvm/Support/InitLLVM.h"
35 #include "llvm/Support/MemoryBuffer.h"
36 #include "llvm/Support/SourceMgr.h"
37 #include "llvm/Support/TargetSelect.h"
38 #include "llvm/Support/ToolOutputFile.h"
39 #include "llvm/Support/WithColor.h"
40 #include "llvm/TargetParser/Host.h"
41 
42 using namespace llvm;
43 
44 static mc::RegisterMCTargetOptionsFlags MOF;
45 
46 static cl::OptionCategory MCCategory("MC Options");
47 
48 static cl::opt<std::string> InputFilename(cl::Positional,
49                                           cl::desc("<input file>"),
50                                           cl::init("-"), cl::cat(MCCategory));
51 
52 static cl::list<std::string>
53     DisassemblerOptions("M", cl::desc("Disassembler options"),
54                         cl::cat(MCCategory));
55 
56 static cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
57                                            cl::value_desc("filename"),
58                                            cl::init("-"), cl::cat(MCCategory));
59 
60 static cl::opt<std::string> SplitDwarfFile("split-dwarf-file",
61                                            cl::desc("DWO output filename"),
62                                            cl::value_desc("filename"),
63                                            cl::cat(MCCategory));
64 
65 static cl::opt<bool> ShowEncoding("show-encoding",
66                                   cl::desc("Show instruction encodings"),
67                                   cl::cat(MCCategory));
68 
69 static cl::opt<bool> RelaxELFRel(
70     "relax-relocations", cl::init(true),
71     cl::desc("Emit R_X86_64_GOTPCRELX instead of R_X86_64_GOTPCREL"),
72     cl::cat(MCCategory));
73 
74 static cl::opt<DebugCompressionType> CompressDebugSections(
75     "compress-debug-sections", cl::ValueOptional,
76     cl::init(DebugCompressionType::None),
77     cl::desc("Choose DWARF debug sections compression:"),
78     cl::values(clEnumValN(DebugCompressionType::None, "none", "No compression"),
79                clEnumValN(DebugCompressionType::Zlib, "zlib", "Use zlib"),
80                clEnumValN(DebugCompressionType::Zstd, "zstd", "Use zstd")),
81     cl::cat(MCCategory));
82 
83 static cl::opt<bool>
84     ShowInst("show-inst", cl::desc("Show internal instruction representation"),
85              cl::cat(MCCategory));
86 
87 static cl::opt<bool>
88     ShowInstOperands("show-inst-operands",
89                      cl::desc("Show instructions operands as parsed"),
90                      cl::cat(MCCategory));
91 
92 static cl::opt<unsigned>
93     OutputAsmVariant("output-asm-variant",
94                      cl::desc("Syntax variant to use for output printing"),
95                      cl::cat(MCCategory));
96 
97 static cl::opt<bool>
98     PrintImmHex("print-imm-hex", cl::init(false),
99                 cl::desc("Prefer hex format for immediate values"),
100                 cl::cat(MCCategory));
101 
102 static cl::list<std::string>
103     DefineSymbol("defsym",
104                  cl::desc("Defines a symbol to be an integer constant"),
105                  cl::cat(MCCategory));
106 
107 static cl::opt<bool>
108     PreserveComments("preserve-comments",
109                      cl::desc("Preserve Comments in outputted assembly"),
110                      cl::cat(MCCategory));
111 
112 enum OutputFileType {
113   OFT_Null,
114   OFT_AssemblyFile,
115   OFT_ObjectFile
116 };
117 static cl::opt<OutputFileType>
118     FileType("filetype", cl::init(OFT_AssemblyFile),
119              cl::desc("Choose an output file type:"),
120              cl::values(clEnumValN(OFT_AssemblyFile, "asm",
121                                    "Emit an assembly ('.s') file"),
122                         clEnumValN(OFT_Null, "null",
123                                    "Don't emit anything (for timing purposes)"),
124                         clEnumValN(OFT_ObjectFile, "obj",
125                                    "Emit a native object ('.o') file")),
126              cl::cat(MCCategory));
127 
128 static cl::list<std::string> IncludeDirs("I",
129                                          cl::desc("Directory of include files"),
130                                          cl::value_desc("directory"),
131                                          cl::Prefix, cl::cat(MCCategory));
132 
133 static cl::opt<std::string>
134     ArchName("arch",
135              cl::desc("Target arch to assemble for, "
136                       "see -version for available targets"),
137              cl::cat(MCCategory));
138 
139 static cl::opt<std::string>
140     TripleName("triple",
141                cl::desc("Target triple to assemble for, "
142                         "see -version for available targets"),
143                cl::cat(MCCategory));
144 
145 static cl::opt<std::string>
146     MCPU("mcpu",
147          cl::desc("Target a specific cpu type (-mcpu=help for details)"),
148          cl::value_desc("cpu-name"), cl::init(""), cl::cat(MCCategory));
149 
150 static cl::list<std::string>
151     MAttrs("mattr", cl::CommaSeparated,
152            cl::desc("Target specific attributes (-mattr=help for details)"),
153            cl::value_desc("a1,+a2,-a3,..."), cl::cat(MCCategory));
154 
155 static cl::opt<bool> PIC("position-independent",
156                          cl::desc("Position independent"), cl::init(false),
157                          cl::cat(MCCategory));
158 
159 static cl::opt<bool>
160     LargeCodeModel("large-code-model",
161                    cl::desc("Create cfi directives that assume the code might "
162                             "be more than 2gb away"),
163                    cl::cat(MCCategory));
164 
165 static cl::opt<bool>
166     NoInitialTextSection("n",
167                          cl::desc("Don't assume assembly file starts "
168                                   "in the text section"),
169                          cl::cat(MCCategory));
170 
171 static cl::opt<bool>
172     GenDwarfForAssembly("g",
173                         cl::desc("Generate dwarf debugging info for assembly "
174                                  "source files"),
175                         cl::cat(MCCategory));
176 
177 static cl::opt<std::string>
178     DebugCompilationDir("fdebug-compilation-dir",
179                         cl::desc("Specifies the debug info's compilation dir"),
180                         cl::cat(MCCategory));
181 
182 static cl::list<std::string> DebugPrefixMap(
183     "fdebug-prefix-map", cl::desc("Map file source paths in debug info"),
184     cl::value_desc("= separated key-value pairs"), cl::cat(MCCategory));
185 
186 static cl::opt<std::string> MainFileName(
187     "main-file-name",
188     cl::desc("Specifies the name we should consider the input file"),
189     cl::cat(MCCategory));
190 
191 static cl::opt<bool> SaveTempLabels("save-temp-labels",
192                                     cl::desc("Don't discard temporary labels"),
193                                     cl::cat(MCCategory));
194 
195 static cl::opt<bool> LexMasmIntegers(
196     "masm-integers",
197     cl::desc("Enable binary and hex masm integers (0b110 and 0ABCh)"),
198     cl::cat(MCCategory));
199 
200 static cl::opt<bool> LexMasmHexFloats(
201     "masm-hexfloats",
202     cl::desc("Enable MASM-style hex float initializers (3F800000r)"),
203     cl::cat(MCCategory));
204 
205 static cl::opt<bool> LexMotorolaIntegers(
206     "motorola-integers",
207     cl::desc("Enable binary and hex Motorola integers (%110 and $ABC)"),
208     cl::cat(MCCategory));
209 
210 static cl::opt<bool> NoExecStack("no-exec-stack",
211                                  cl::desc("File doesn't need an exec stack"),
212                                  cl::cat(MCCategory));
213 
214 enum ActionType {
215   AC_AsLex,
216   AC_Assemble,
217   AC_Disassemble,
218   AC_MDisassemble,
219   AC_CDisassemble,
220 };
221 
222 static cl::opt<ActionType> Action(
223     cl::desc("Action to perform:"), cl::init(AC_Assemble),
224     cl::values(clEnumValN(AC_AsLex, "as-lex", "Lex tokens from a .s file"),
225                clEnumValN(AC_Assemble, "assemble",
226                           "Assemble a .s file (default)"),
227                clEnumValN(AC_Disassemble, "disassemble",
228                           "Disassemble strings of hex bytes"),
229                clEnumValN(AC_MDisassemble, "mdis",
230                           "Marked up disassembly of strings of hex bytes"),
231                clEnumValN(AC_CDisassemble, "cdis",
232                           "Colored disassembly of strings of hex bytes")),
233     cl::cat(MCCategory));
234 
235 static const Target *GetTarget(const char *ProgName) {
236   // Figure out the target triple.
237   if (TripleName.empty())
238     TripleName = sys::getDefaultTargetTriple();
239   Triple TheTriple(Triple::normalize(TripleName));
240 
241   // Get the target specific parser.
242   std::string Error;
243   const Target *TheTarget = TargetRegistry::lookupTarget(ArchName, TheTriple,
244                                                          Error);
245   if (!TheTarget) {
246     WithColor::error(errs(), ProgName) << Error;
247     return nullptr;
248   }
249 
250   // Update the triple name and return the found target.
251   TripleName = TheTriple.getTriple();
252   return TheTarget;
253 }
254 
255 static std::unique_ptr<ToolOutputFile> GetOutputStream(StringRef Path,
256     sys::fs::OpenFlags Flags) {
257   std::error_code EC;
258   auto Out = std::make_unique<ToolOutputFile>(Path, EC, Flags);
259   if (EC) {
260     WithColor::error() << EC.message() << '\n';
261     return nullptr;
262   }
263 
264   return Out;
265 }
266 
267 static std::string DwarfDebugFlags;
268 static void setDwarfDebugFlags(int argc, char **argv) {
269   if (!getenv("RC_DEBUG_OPTIONS"))
270     return;
271   for (int i = 0; i < argc; i++) {
272     DwarfDebugFlags += argv[i];
273     if (i + 1 < argc)
274       DwarfDebugFlags += " ";
275   }
276 }
277 
278 static std::string DwarfDebugProducer;
279 static void setDwarfDebugProducer() {
280   if(!getenv("DEBUG_PRODUCER"))
281     return;
282   DwarfDebugProducer += getenv("DEBUG_PRODUCER");
283 }
284 
285 static int AsLexInput(SourceMgr &SrcMgr, MCAsmInfo &MAI,
286                       raw_ostream &OS) {
287 
288   AsmLexer Lexer(MAI);
289   Lexer.setBuffer(SrcMgr.getMemoryBuffer(SrcMgr.getMainFileID())->getBuffer());
290 
291   bool Error = false;
292   while (Lexer.Lex().isNot(AsmToken::Eof)) {
293     Lexer.getTok().dump(OS);
294     OS << "\n";
295     if (Lexer.getTok().getKind() == AsmToken::Error)
296       Error = true;
297   }
298 
299   return Error;
300 }
301 
302 static int fillCommandLineSymbols(MCAsmParser &Parser) {
303   for (auto &I: DefineSymbol) {
304     auto Pair = StringRef(I).split('=');
305     auto Sym = Pair.first;
306     auto Val = Pair.second;
307 
308     if (Sym.empty() || Val.empty()) {
309       WithColor::error() << "defsym must be of the form: sym=value: " << I
310                          << "\n";
311       return 1;
312     }
313     int64_t Value;
314     if (Val.getAsInteger(0, Value)) {
315       WithColor::error() << "value is not an integer: " << Val << "\n";
316       return 1;
317     }
318     Parser.getContext().setSymbolValue(Parser.getStreamer(), Sym, Value);
319   }
320   return 0;
321 }
322 
323 static int AssembleInput(const char *ProgName, const Target *TheTarget,
324                          SourceMgr &SrcMgr, MCContext &Ctx, MCStreamer &Str,
325                          MCAsmInfo &MAI, MCSubtargetInfo &STI,
326                          MCInstrInfo &MCII, MCTargetOptions const &MCOptions) {
327   std::unique_ptr<MCAsmParser> Parser(
328       createMCAsmParser(SrcMgr, Ctx, Str, MAI));
329   std::unique_ptr<MCTargetAsmParser> TAP(
330       TheTarget->createMCAsmParser(STI, *Parser, MCII, MCOptions));
331 
332   if (!TAP) {
333     WithColor::error(errs(), ProgName)
334         << "this target does not support assembly parsing.\n";
335     return 1;
336   }
337 
338   int SymbolResult = fillCommandLineSymbols(*Parser);
339   if(SymbolResult)
340     return SymbolResult;
341   Parser->setShowParsedOperands(ShowInstOperands);
342   Parser->setTargetParser(*TAP);
343   Parser->getLexer().setLexMasmIntegers(LexMasmIntegers);
344   Parser->getLexer().setLexMasmHexFloats(LexMasmHexFloats);
345   Parser->getLexer().setLexMotorolaIntegers(LexMotorolaIntegers);
346 
347   int Res = Parser->Run(NoInitialTextSection);
348 
349   return Res;
350 }
351 
352 int main(int argc, char **argv) {
353   InitLLVM X(argc, argv);
354 
355   // Initialize targets and assembly printers/parsers.
356   llvm::InitializeAllTargetInfos();
357   llvm::InitializeAllTargetMCs();
358   llvm::InitializeAllAsmParsers();
359   llvm::InitializeAllDisassemblers();
360 
361   // Register the target printer for --version.
362   cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);
363 
364   cl::HideUnrelatedOptions({&MCCategory, &getColorCategory()});
365   cl::ParseCommandLineOptions(argc, argv, "llvm machine code playground\n");
366   const MCTargetOptions MCOptions = mc::InitMCTargetOptionsFromFlags();
367   setDwarfDebugFlags(argc, argv);
368 
369   setDwarfDebugProducer();
370 
371   const char *ProgName = argv[0];
372   const Target *TheTarget = GetTarget(ProgName);
373   if (!TheTarget)
374     return 1;
375   // Now that GetTarget() has (potentially) replaced TripleName, it's safe to
376   // construct the Triple object.
377   Triple TheTriple(TripleName);
378 
379   ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr =
380       MemoryBuffer::getFileOrSTDIN(InputFilename, /*IsText=*/true);
381   if (std::error_code EC = BufferPtr.getError()) {
382     WithColor::error(errs(), ProgName)
383         << InputFilename << ": " << EC.message() << '\n';
384     return 1;
385   }
386   MemoryBuffer *Buffer = BufferPtr->get();
387 
388   SourceMgr SrcMgr;
389 
390   // Tell SrcMgr about this buffer, which is what the parser will pick up.
391   SrcMgr.AddNewSourceBuffer(std::move(*BufferPtr), SMLoc());
392 
393   // Record the location of the include directories so that the lexer can find
394   // it later.
395   SrcMgr.setIncludeDirs(IncludeDirs);
396 
397   std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
398   assert(MRI && "Unable to create target register info!");
399 
400   std::unique_ptr<MCAsmInfo> MAI(
401       TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
402   assert(MAI && "Unable to create target asm info!");
403 
404   MAI->setRelaxELFRelocations(RelaxELFRel);
405   if (CompressDebugSections != DebugCompressionType::None) {
406     if (const char *Reason = compression::getReasonIfUnsupported(
407             compression::formatFor(CompressDebugSections))) {
408       WithColor::error(errs(), ProgName)
409           << "--compress-debug-sections: " << Reason;
410       return 1;
411     }
412   }
413   MAI->setCompressDebugSections(CompressDebugSections);
414   MAI->setPreserveAsmComments(PreserveComments);
415 
416   // Package up features to be passed to target/subtarget
417   std::string FeaturesStr;
418   if (MAttrs.size()) {
419     SubtargetFeatures Features;
420     for (unsigned i = 0; i != MAttrs.size(); ++i)
421       Features.AddFeature(MAttrs[i]);
422     FeaturesStr = Features.getString();
423   }
424 
425   std::unique_ptr<MCSubtargetInfo> STI(
426       TheTarget->createMCSubtargetInfo(TripleName, MCPU, FeaturesStr));
427   assert(STI && "Unable to create subtarget info!");
428 
429   // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
430   // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
431   MCContext Ctx(TheTriple, MAI.get(), MRI.get(), STI.get(), &SrcMgr,
432                 &MCOptions);
433   std::unique_ptr<MCObjectFileInfo> MOFI(
434       TheTarget->createMCObjectFileInfo(Ctx, PIC, LargeCodeModel));
435   Ctx.setObjectFileInfo(MOFI.get());
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 > 5) {
444     errs() << ProgName << ": Dwarf version " << DwarfVersion
445            << " is not supported." << '\n';
446     return 1;
447   }
448   Ctx.setDwarfVersion(DwarfVersion);
449   if (MCOptions.Dwarf64) {
450     // The 64-bit DWARF format was introduced in DWARFv3.
451     if (DwarfVersion < 3) {
452       errs() << ProgName
453              << ": the 64-bit DWARF format is not supported for DWARF versions "
454                 "prior to 3\n";
455       return 1;
456     }
457     // 32-bit targets don't support DWARF64, which requires 64-bit relocations.
458     if (MAI->getCodePointerSize() < 8) {
459       errs() << ProgName
460              << ": the 64-bit DWARF format is only supported for 64-bit "
461                 "targets\n";
462       return 1;
463     }
464     // If needsDwarfSectionOffsetDirective is true, we would eventually call
465     // MCStreamer::emitSymbolValue() with IsSectionRelative = true, but that
466     // is supported only for 4-byte long references.
467     if (MAI->needsDwarfSectionOffsetDirective()) {
468       errs() << ProgName << ": the 64-bit DWARF format is not supported for "
469              << TheTriple.normalize() << "\n";
470       return 1;
471     }
472     Ctx.setDwarfFormat(dwarf::DWARF64);
473   }
474   if (!DwarfDebugFlags.empty())
475     Ctx.setDwarfDebugFlags(StringRef(DwarfDebugFlags));
476   if (!DwarfDebugProducer.empty())
477     Ctx.setDwarfDebugProducer(StringRef(DwarfDebugProducer));
478   if (!DebugCompilationDir.empty())
479     Ctx.setCompilationDir(DebugCompilationDir);
480   else {
481     // If no compilation dir is set, try to use the current directory.
482     SmallString<128> CWD;
483     if (!sys::fs::current_path(CWD))
484       Ctx.setCompilationDir(CWD);
485   }
486   for (const auto &Arg : DebugPrefixMap) {
487     const auto &KV = StringRef(Arg).split('=');
488     Ctx.addDebugPrefixMapEntry(std::string(KV.first), std::string(KV.second));
489   }
490   if (!MainFileName.empty())
491     Ctx.setMainFileName(MainFileName);
492   if (GenDwarfForAssembly)
493     Ctx.setGenDwarfRootFile(InputFilename, Buffer->getBuffer());
494 
495   sys::fs::OpenFlags Flags = (FileType == OFT_AssemblyFile)
496                                  ? sys::fs::OF_TextWithCRLF
497                                  : sys::fs::OF_None;
498   std::unique_ptr<ToolOutputFile> Out = GetOutputStream(OutputFilename, Flags);
499   if (!Out)
500     return 1;
501 
502   std::unique_ptr<ToolOutputFile> DwoOut;
503   if (!SplitDwarfFile.empty()) {
504     if (FileType != OFT_ObjectFile) {
505       WithColor::error() << "dwo output only supported with object files\n";
506       return 1;
507     }
508     DwoOut = GetOutputStream(SplitDwarfFile, sys::fs::OF_None);
509     if (!DwoOut)
510       return 1;
511   }
512 
513   std::unique_ptr<buffer_ostream> BOS;
514   raw_pwrite_stream *OS = &Out->os();
515   std::unique_ptr<MCStreamer> Str;
516 
517   std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
518   assert(MCII && "Unable to create instruction info!");
519 
520   MCInstPrinter *IP = nullptr;
521   if (FileType == OFT_AssemblyFile) {
522     IP = TheTarget->createMCInstPrinter(Triple(TripleName), OutputAsmVariant,
523                                         *MAI, *MCII, *MRI);
524 
525     if (!IP) {
526       WithColor::error()
527           << "unable to create instruction printer for target triple '"
528           << TheTriple.normalize() << "' with assembly variant "
529           << OutputAsmVariant << ".\n";
530       return 1;
531     }
532 
533     for (StringRef Opt : DisassemblerOptions)
534       if (!IP->applyTargetSpecificCLOption(Opt)) {
535         WithColor::error() << "invalid disassembler option '" << Opt << "'\n";
536         return 1;
537       }
538 
539     // Set the display preference for hex vs. decimal immediates.
540     IP->setPrintImmHex(PrintImmHex);
541 
542     // Set up the AsmStreamer.
543     std::unique_ptr<MCCodeEmitter> CE;
544     if (ShowEncoding)
545       CE.reset(TheTarget->createMCCodeEmitter(*MCII, Ctx));
546 
547     std::unique_ptr<MCAsmBackend> MAB(
548         TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
549     auto FOut = std::make_unique<formatted_raw_ostream>(*OS);
550     // FIXME: Workaround for bug in formatted_raw_ostream. Color escape codes
551     // are (incorrectly) written directly to the unbuffered raw_ostream wrapped
552     // by the formatted_raw_ostream.
553     if (Action == AC_CDisassemble)
554       FOut->SetUnbuffered();
555     Str.reset(
556         TheTarget->createAsmStreamer(Ctx, std::move(FOut), /*asmverbose*/ true,
557                                      /*useDwarfDirectory*/ true, IP,
558                                      std::move(CE), std::move(MAB), ShowInst));
559 
560   } else if (FileType == OFT_Null) {
561     Str.reset(TheTarget->createNullStreamer(Ctx));
562   } else {
563     assert(FileType == OFT_ObjectFile && "Invalid file type!");
564 
565     if (!Out->os().supportsSeeking()) {
566       BOS = std::make_unique<buffer_ostream>(Out->os());
567       OS = BOS.get();
568     }
569 
570     MCCodeEmitter *CE = TheTarget->createMCCodeEmitter(*MCII, Ctx);
571     MCAsmBackend *MAB = TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions);
572     Str.reset(TheTarget->createMCObjectStreamer(
573         TheTriple, Ctx, std::unique_ptr<MCAsmBackend>(MAB),
574         DwoOut ? MAB->createDwoObjectWriter(*OS, DwoOut->os())
575                : MAB->createObjectWriter(*OS),
576         std::unique_ptr<MCCodeEmitter>(CE), *STI, MCOptions.MCRelaxAll,
577         MCOptions.MCIncrementalLinkerCompatible,
578         /*DWARFMustBeAtTheEnd*/ false));
579     if (NoExecStack)
580       Str->initSections(true, *STI);
581   }
582 
583   // Use Assembler information for parsing.
584   Str->setUseAssemblerInfoForParsing(true);
585 
586   int Res = 1;
587   bool disassemble = false;
588   switch (Action) {
589   case AC_AsLex:
590     Res = AsLexInput(SrcMgr, *MAI, Out->os());
591     break;
592   case AC_Assemble:
593     Res = AssembleInput(ProgName, TheTarget, SrcMgr, Ctx, *Str, *MAI, *STI,
594                         *MCII, MCOptions);
595     break;
596   case AC_MDisassemble:
597     IP->setUseMarkup(true);
598     disassemble = true;
599     break;
600   case AC_CDisassemble:
601     IP->setUseColor(true);
602     disassemble = true;
603     break;
604   case AC_Disassemble:
605     disassemble = true;
606     break;
607   }
608   if (disassemble)
609     Res = Disassembler::disassemble(*TheTarget, TripleName, *STI, *Str, *Buffer,
610                                     SrcMgr, Ctx, MCOptions);
611 
612   // Keep output if no errors.
613   if (Res == 0) {
614     Out->keep();
615     if (DwoOut)
616       DwoOut->keep();
617   }
618   return Res;
619 }
620