xref: /freebsd/contrib/llvm-project/clang/tools/driver/cc1as_main.cpp (revision b64c5a0ace59af62eff52bfe110a521dc73c937b) 
1 //===-- cc1as_main.cpp - Clang Assembler  ---------------------------------===//
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 is the entry point to the clang -cc1as functionality, which implements
10 // the direct interface to the LLVM MC based assembler.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Basic/Diagnostic.h"
15 #include "clang/Basic/DiagnosticOptions.h"
16 #include "clang/Driver/DriverDiagnostic.h"
17 #include "clang/Driver/Options.h"
18 #include "clang/Frontend/FrontendDiagnostic.h"
19 #include "clang/Frontend/TextDiagnosticPrinter.h"
20 #include "clang/Frontend/Utils.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/StringSwitch.h"
24 #include "llvm/IR/DataLayout.h"
25 #include "llvm/MC/MCAsmBackend.h"
26 #include "llvm/MC/MCAsmInfo.h"
27 #include "llvm/MC/MCCodeEmitter.h"
28 #include "llvm/MC/MCContext.h"
29 #include "llvm/MC/MCInstrInfo.h"
30 #include "llvm/MC/MCObjectFileInfo.h"
31 #include "llvm/MC/MCObjectWriter.h"
32 #include "llvm/MC/MCParser/MCAsmParser.h"
33 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
34 #include "llvm/MC/MCRegisterInfo.h"
35 #include "llvm/MC/MCSectionMachO.h"
36 #include "llvm/MC/MCStreamer.h"
37 #include "llvm/MC/MCSubtargetInfo.h"
38 #include "llvm/MC/MCTargetOptions.h"
39 #include "llvm/MC/TargetRegistry.h"
40 #include "llvm/Option/Arg.h"
41 #include "llvm/Option/ArgList.h"
42 #include "llvm/Option/OptTable.h"
43 #include "llvm/Support/CommandLine.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/FileSystem.h"
46 #include "llvm/Support/FormattedStream.h"
47 #include "llvm/Support/MemoryBuffer.h"
48 #include "llvm/Support/Path.h"
49 #include "llvm/Support/Process.h"
50 #include "llvm/Support/Signals.h"
51 #include "llvm/Support/SourceMgr.h"
52 #include "llvm/Support/TargetSelect.h"
53 #include "llvm/Support/Timer.h"
54 #include "llvm/Support/raw_ostream.h"
55 #include "llvm/TargetParser/Host.h"
56 #include "llvm/TargetParser/Triple.h"
57 #include <memory>
58 #include <optional>
59 #include <system_error>
60 using namespace clang;
61 using namespace clang::driver;
62 using namespace clang::driver::options;
63 using namespace llvm;
64 using namespace llvm::opt;
65 
66 namespace {
67 
68 /// Helper class for representing a single invocation of the assembler.
69 struct AssemblerInvocation {
70   /// @name Target Options
71   /// @{
72 
73   /// The name of the target triple to assemble for.
74   std::string Triple;
75 
76   /// If given, the name of the target CPU to determine which instructions
77   /// are legal.
78   std::string CPU;
79 
80   /// The list of target specific features to enable or disable -- this should
81   /// be a list of strings starting with '+' or '-'.
82   std::vector<std::string> Features;
83 
84   /// The list of symbol definitions.
85   std::vector<std::string> SymbolDefs;
86 
87   /// @}
88   /// @name Language Options
89   /// @{
90 
91   std::vector<std::string> IncludePaths;
92   LLVM_PREFERRED_TYPE(bool)
93   unsigned NoInitialTextSection : 1;
94   LLVM_PREFERRED_TYPE(bool)
95   unsigned SaveTemporaryLabels : 1;
96   LLVM_PREFERRED_TYPE(bool)
97   unsigned GenDwarfForAssembly : 1;
98   LLVM_PREFERRED_TYPE(bool)
99   unsigned RelaxELFRelocations : 1;
100   LLVM_PREFERRED_TYPE(bool)
101   unsigned SSE2AVX : 1;
102   LLVM_PREFERRED_TYPE(bool)
103   unsigned Dwarf64 : 1;
104   unsigned DwarfVersion;
105   std::string DwarfDebugFlags;
106   std::string DwarfDebugProducer;
107   std::string DebugCompilationDir;
108   llvm::SmallVector<std::pair<std::string, std::string>, 0> DebugPrefixMap;
109   llvm::DebugCompressionType CompressDebugSections =
110       llvm::DebugCompressionType::None;
111   std::string MainFileName;
112   std::string SplitDwarfOutput;
113 
114   /// @}
115   /// @name Frontend Options
116   /// @{
117 
118   std::string InputFile;
119   std::vector<std::string> LLVMArgs;
120   std::string OutputPath;
121   enum FileType {
122     FT_Asm,  ///< Assembly (.s) output, transliterate mode.
123     FT_Null, ///< No output, for timing purposes.
124     FT_Obj   ///< Object file output.
125   };
126   FileType OutputType;
127   LLVM_PREFERRED_TYPE(bool)
128   unsigned ShowHelp : 1;
129   LLVM_PREFERRED_TYPE(bool)
130   unsigned ShowVersion : 1;
131 
132   /// @}
133   /// @name Transliterate Options
134   /// @{
135 
136   unsigned OutputAsmVariant;
137   LLVM_PREFERRED_TYPE(bool)
138   unsigned ShowEncoding : 1;
139   LLVM_PREFERRED_TYPE(bool)
140   unsigned ShowInst : 1;
141 
142   /// @}
143   /// @name Assembler Options
144   /// @{
145 
146   LLVM_PREFERRED_TYPE(bool)
147   unsigned RelaxAll : 1;
148   LLVM_PREFERRED_TYPE(bool)
149   unsigned NoExecStack : 1;
150   LLVM_PREFERRED_TYPE(bool)
151   unsigned FatalWarnings : 1;
152   LLVM_PREFERRED_TYPE(bool)
153   unsigned NoWarn : 1;
154   LLVM_PREFERRED_TYPE(bool)
155   unsigned NoTypeCheck : 1;
156   LLVM_PREFERRED_TYPE(bool)
157   unsigned IncrementalLinkerCompatible : 1;
158   LLVM_PREFERRED_TYPE(bool)
159   unsigned EmbedBitcode : 1;
160 
161   /// Whether to emit DWARF unwind info.
162   EmitDwarfUnwindType EmitDwarfUnwind;
163 
164   // Whether to emit compact-unwind for non-canonical entries.
165   // Note: maybe overriden by other constraints.
166   LLVM_PREFERRED_TYPE(bool)
167   unsigned EmitCompactUnwindNonCanonical : 1;
168 
169   LLVM_PREFERRED_TYPE(bool)
170   unsigned Crel : 1;
171 
172   /// The name of the relocation model to use.
173   std::string RelocationModel;
174 
175   /// The ABI targeted by the backend. Specified using -target-abi. Empty
176   /// otherwise.
177   std::string TargetABI;
178 
179   /// Darwin target variant triple, the variant of the deployment target
180   /// for which the code is being compiled.
181   std::optional<llvm::Triple> DarwinTargetVariantTriple;
182 
183   /// The version of the darwin target variant SDK which was used during the
184   /// compilation
185   llvm::VersionTuple DarwinTargetVariantSDKVersion;
186 
187   /// The name of a file to use with \c .secure_log_unique directives.
188   std::string AsSecureLogFile;
189   /// @}
190 
191 public:
192   AssemblerInvocation() {
193     Triple = "";
194     NoInitialTextSection = 0;
195     InputFile = "-";
196     OutputPath = "-";
197     OutputType = FT_Asm;
198     OutputAsmVariant = 0;
199     ShowInst = 0;
200     ShowEncoding = 0;
201     RelaxAll = 0;
202     SSE2AVX = 0;
203     NoExecStack = 0;
204     FatalWarnings = 0;
205     NoWarn = 0;
206     NoTypeCheck = 0;
207     IncrementalLinkerCompatible = 0;
208     Dwarf64 = 0;
209     DwarfVersion = 0;
210     EmbedBitcode = 0;
211     EmitDwarfUnwind = EmitDwarfUnwindType::Default;
212     EmitCompactUnwindNonCanonical = false;
213     Crel = false;
214   }
215 
216   static bool CreateFromArgs(AssemblerInvocation &Res,
217                              ArrayRef<const char *> Argv,
218                              DiagnosticsEngine &Diags);
219 };
220 
221 }
222 
223 bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
224                                          ArrayRef<const char *> Argv,
225                                          DiagnosticsEngine &Diags) {
226   bool Success = true;
227 
228   // Parse the arguments.
229   const OptTable &OptTbl = getDriverOptTable();
230 
231   llvm::opt::Visibility VisibilityMask(options::CC1AsOption);
232   unsigned MissingArgIndex, MissingArgCount;
233   InputArgList Args =
234       OptTbl.ParseArgs(Argv, MissingArgIndex, MissingArgCount, VisibilityMask);
235 
236   // Check for missing argument error.
237   if (MissingArgCount) {
238     Diags.Report(diag::err_drv_missing_argument)
239         << Args.getArgString(MissingArgIndex) << MissingArgCount;
240     Success = false;
241   }
242 
243   // Issue errors on unknown arguments.
244   for (const Arg *A : Args.filtered(OPT_UNKNOWN)) {
245     auto ArgString = A->getAsString(Args);
246     std::string Nearest;
247     if (OptTbl.findNearest(ArgString, Nearest, VisibilityMask) > 1)
248       Diags.Report(diag::err_drv_unknown_argument) << ArgString;
249     else
250       Diags.Report(diag::err_drv_unknown_argument_with_suggestion)
251           << ArgString << Nearest;
252     Success = false;
253   }
254 
255   // Construct the invocation.
256 
257   // Target Options
258   Opts.Triple = llvm::Triple::normalize(Args.getLastArgValue(OPT_triple));
259   if (Arg *A = Args.getLastArg(options::OPT_darwin_target_variant_triple))
260     Opts.DarwinTargetVariantTriple = llvm::Triple(A->getValue());
261   if (Arg *A = Args.getLastArg(OPT_darwin_target_variant_sdk_version_EQ)) {
262     VersionTuple Version;
263     if (Version.tryParse(A->getValue()))
264       Diags.Report(diag::err_drv_invalid_value)
265           << A->getAsString(Args) << A->getValue();
266     else
267       Opts.DarwinTargetVariantSDKVersion = Version;
268   }
269 
270   Opts.CPU = std::string(Args.getLastArgValue(OPT_target_cpu));
271   Opts.Features = Args.getAllArgValues(OPT_target_feature);
272 
273   // Use the default target triple if unspecified.
274   if (Opts.Triple.empty())
275     Opts.Triple = llvm::sys::getDefaultTargetTriple();
276 
277   // Language Options
278   Opts.IncludePaths = Args.getAllArgValues(OPT_I);
279   Opts.NoInitialTextSection = Args.hasArg(OPT_n);
280   Opts.SaveTemporaryLabels = Args.hasArg(OPT_msave_temp_labels);
281   // Any DebugInfoKind implies GenDwarfForAssembly.
282   Opts.GenDwarfForAssembly = Args.hasArg(OPT_debug_info_kind_EQ);
283 
284   if (const Arg *A = Args.getLastArg(OPT_compress_debug_sections_EQ)) {
285     Opts.CompressDebugSections =
286         llvm::StringSwitch<llvm::DebugCompressionType>(A->getValue())
287             .Case("none", llvm::DebugCompressionType::None)
288             .Case("zlib", llvm::DebugCompressionType::Zlib)
289             .Case("zstd", llvm::DebugCompressionType::Zstd)
290             .Default(llvm::DebugCompressionType::None);
291   }
292 
293   Opts.RelaxELFRelocations = !Args.hasArg(OPT_mrelax_relocations_no);
294   Opts.SSE2AVX = Args.hasArg(OPT_msse2avx);
295   if (auto *DwarfFormatArg = Args.getLastArg(OPT_gdwarf64, OPT_gdwarf32))
296     Opts.Dwarf64 = DwarfFormatArg->getOption().matches(OPT_gdwarf64);
297   Opts.DwarfVersion = getLastArgIntValue(Args, OPT_dwarf_version_EQ, 2, Diags);
298   Opts.DwarfDebugFlags =
299       std::string(Args.getLastArgValue(OPT_dwarf_debug_flags));
300   Opts.DwarfDebugProducer =
301       std::string(Args.getLastArgValue(OPT_dwarf_debug_producer));
302   if (const Arg *A = Args.getLastArg(options::OPT_ffile_compilation_dir_EQ,
303                                      options::OPT_fdebug_compilation_dir_EQ))
304     Opts.DebugCompilationDir = A->getValue();
305   Opts.MainFileName = std::string(Args.getLastArgValue(OPT_main_file_name));
306 
307   for (const auto &Arg : Args.getAllArgValues(OPT_fdebug_prefix_map_EQ)) {
308     auto Split = StringRef(Arg).split('=');
309     Opts.DebugPrefixMap.emplace_back(Split.first, Split.second);
310   }
311 
312   // Frontend Options
313   if (Args.hasArg(OPT_INPUT)) {
314     bool First = true;
315     for (const Arg *A : Args.filtered(OPT_INPUT)) {
316       if (First) {
317         Opts.InputFile = A->getValue();
318         First = false;
319       } else {
320         Diags.Report(diag::err_drv_unknown_argument) << A->getAsString(Args);
321         Success = false;
322       }
323     }
324   }
325   Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
326   Opts.OutputPath = std::string(Args.getLastArgValue(OPT_o));
327   Opts.SplitDwarfOutput =
328       std::string(Args.getLastArgValue(OPT_split_dwarf_output));
329   if (Arg *A = Args.getLastArg(OPT_filetype)) {
330     StringRef Name = A->getValue();
331     unsigned OutputType = StringSwitch<unsigned>(Name)
332       .Case("asm", FT_Asm)
333       .Case("null", FT_Null)
334       .Case("obj", FT_Obj)
335       .Default(~0U);
336     if (OutputType == ~0U) {
337       Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Name;
338       Success = false;
339     } else
340       Opts.OutputType = FileType(OutputType);
341   }
342   Opts.ShowHelp = Args.hasArg(OPT_help);
343   Opts.ShowVersion = Args.hasArg(OPT_version);
344 
345   // Transliterate Options
346   Opts.OutputAsmVariant =
347       getLastArgIntValue(Args, OPT_output_asm_variant, 0, Diags);
348   Opts.ShowEncoding = Args.hasArg(OPT_show_encoding);
349   Opts.ShowInst = Args.hasArg(OPT_show_inst);
350 
351   // Assemble Options
352   Opts.RelaxAll = Args.hasArg(OPT_mrelax_all);
353   Opts.NoExecStack = Args.hasArg(OPT_mno_exec_stack);
354   Opts.FatalWarnings = Args.hasArg(OPT_massembler_fatal_warnings);
355   Opts.NoWarn = Args.hasArg(OPT_massembler_no_warn);
356   Opts.NoTypeCheck = Args.hasArg(OPT_mno_type_check);
357   Opts.RelocationModel =
358       std::string(Args.getLastArgValue(OPT_mrelocation_model, "pic"));
359   Opts.TargetABI = std::string(Args.getLastArgValue(OPT_target_abi));
360   Opts.IncrementalLinkerCompatible =
361       Args.hasArg(OPT_mincremental_linker_compatible);
362   Opts.SymbolDefs = Args.getAllArgValues(OPT_defsym);
363 
364   // EmbedBitcode Option. If -fembed-bitcode is enabled, set the flag.
365   // EmbedBitcode behaves the same for all embed options for assembly files.
366   if (auto *A = Args.getLastArg(OPT_fembed_bitcode_EQ)) {
367     Opts.EmbedBitcode = llvm::StringSwitch<unsigned>(A->getValue())
368                             .Case("all", 1)
369                             .Case("bitcode", 1)
370                             .Case("marker", 1)
371                             .Default(0);
372   }
373 
374   if (auto *A = Args.getLastArg(OPT_femit_dwarf_unwind_EQ)) {
375     Opts.EmitDwarfUnwind =
376         llvm::StringSwitch<EmitDwarfUnwindType>(A->getValue())
377             .Case("always", EmitDwarfUnwindType::Always)
378             .Case("no-compact-unwind", EmitDwarfUnwindType::NoCompactUnwind)
379             .Case("default", EmitDwarfUnwindType::Default);
380   }
381 
382   Opts.EmitCompactUnwindNonCanonical =
383       Args.hasArg(OPT_femit_compact_unwind_non_canonical);
384   Opts.Crel = Args.hasArg(OPT_crel);
385 
386   Opts.AsSecureLogFile = Args.getLastArgValue(OPT_as_secure_log_file);
387 
388   return Success;
389 }
390 
391 static std::unique_ptr<raw_fd_ostream>
392 getOutputStream(StringRef Path, DiagnosticsEngine &Diags, bool Binary) {
393   // Make sure that the Out file gets unlinked from the disk if we get a
394   // SIGINT.
395   if (Path != "-")
396     sys::RemoveFileOnSignal(Path);
397 
398   std::error_code EC;
399   auto Out = std::make_unique<raw_fd_ostream>(
400       Path, EC, (Binary ? sys::fs::OF_None : sys::fs::OF_TextWithCRLF));
401   if (EC) {
402     Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
403     return nullptr;
404   }
405 
406   return Out;
407 }
408 
409 static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
410                                  DiagnosticsEngine &Diags) {
411   // Get the target specific parser.
412   std::string Error;
413   const Target *TheTarget = TargetRegistry::lookupTarget(Opts.Triple, Error);
414   if (!TheTarget)
415     return Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
416 
417   ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer =
418       MemoryBuffer::getFileOrSTDIN(Opts.InputFile, /*IsText=*/true);
419 
420   if (std::error_code EC = Buffer.getError()) {
421     return Diags.Report(diag::err_fe_error_reading)
422            << Opts.InputFile << EC.message();
423   }
424 
425   SourceMgr SrcMgr;
426 
427   // Tell SrcMgr about this buffer, which is what the parser will pick up.
428   unsigned BufferIndex = SrcMgr.AddNewSourceBuffer(std::move(*Buffer), SMLoc());
429 
430   // Record the location of the include directories so that the lexer can find
431   // it later.
432   SrcMgr.setIncludeDirs(Opts.IncludePaths);
433 
434   std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(Opts.Triple));
435   assert(MRI && "Unable to create target register info!");
436 
437   MCTargetOptions MCOptions;
438   MCOptions.MCRelaxAll = Opts.RelaxAll;
439   MCOptions.EmitDwarfUnwind = Opts.EmitDwarfUnwind;
440   MCOptions.EmitCompactUnwindNonCanonical = Opts.EmitCompactUnwindNonCanonical;
441   MCOptions.MCSaveTempLabels = Opts.SaveTemporaryLabels;
442   MCOptions.Crel = Opts.Crel;
443   MCOptions.X86RelaxRelocations = Opts.RelaxELFRelocations;
444   MCOptions.X86Sse2Avx = Opts.SSE2AVX;
445   MCOptions.CompressDebugSections = Opts.CompressDebugSections;
446   MCOptions.AsSecureLogFile = Opts.AsSecureLogFile;
447 
448   std::unique_ptr<MCAsmInfo> MAI(
449       TheTarget->createMCAsmInfo(*MRI, Opts.Triple, MCOptions));
450   assert(MAI && "Unable to create target asm info!");
451 
452   // Ensure MCAsmInfo initialization occurs before any use, otherwise sections
453   // may be created with a combination of default and explicit settings.
454 
455 
456   bool IsBinary = Opts.OutputType == AssemblerInvocation::FT_Obj;
457   if (Opts.OutputPath.empty())
458     Opts.OutputPath = "-";
459   std::unique_ptr<raw_fd_ostream> FDOS =
460       getOutputStream(Opts.OutputPath, Diags, IsBinary);
461   if (!FDOS)
462     return true;
463   std::unique_ptr<raw_fd_ostream> DwoOS;
464   if (!Opts.SplitDwarfOutput.empty())
465     DwoOS = getOutputStream(Opts.SplitDwarfOutput, Diags, IsBinary);
466 
467   // Build up the feature string from the target feature list.
468   std::string FS = llvm::join(Opts.Features, ",");
469 
470   std::unique_ptr<MCSubtargetInfo> STI(
471       TheTarget->createMCSubtargetInfo(Opts.Triple, Opts.CPU, FS));
472   assert(STI && "Unable to create subtarget info!");
473 
474   MCContext Ctx(Triple(Opts.Triple), MAI.get(), MRI.get(), STI.get(), &SrcMgr,
475                 &MCOptions);
476 
477   bool PIC = false;
478   if (Opts.RelocationModel == "static") {
479     PIC = false;
480   } else if (Opts.RelocationModel == "pic") {
481     PIC = true;
482   } else {
483     assert(Opts.RelocationModel == "dynamic-no-pic" &&
484            "Invalid PIC model!");
485     PIC = false;
486   }
487 
488   // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
489   // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
490   std::unique_ptr<MCObjectFileInfo> MOFI(
491       TheTarget->createMCObjectFileInfo(Ctx, PIC));
492   if (Opts.DarwinTargetVariantTriple)
493     MOFI->setDarwinTargetVariantTriple(*Opts.DarwinTargetVariantTriple);
494   if (!Opts.DarwinTargetVariantSDKVersion.empty())
495     MOFI->setDarwinTargetVariantSDKVersion(Opts.DarwinTargetVariantSDKVersion);
496   Ctx.setObjectFileInfo(MOFI.get());
497 
498   if (Opts.GenDwarfForAssembly)
499     Ctx.setGenDwarfForAssembly(true);
500   if (!Opts.DwarfDebugFlags.empty())
501     Ctx.setDwarfDebugFlags(StringRef(Opts.DwarfDebugFlags));
502   if (!Opts.DwarfDebugProducer.empty())
503     Ctx.setDwarfDebugProducer(StringRef(Opts.DwarfDebugProducer));
504   if (!Opts.DebugCompilationDir.empty())
505     Ctx.setCompilationDir(Opts.DebugCompilationDir);
506   else {
507     // If no compilation dir is set, try to use the current directory.
508     SmallString<128> CWD;
509     if (!sys::fs::current_path(CWD))
510       Ctx.setCompilationDir(CWD);
511   }
512   if (!Opts.DebugPrefixMap.empty())
513     for (const auto &KV : Opts.DebugPrefixMap)
514       Ctx.addDebugPrefixMapEntry(KV.first, KV.second);
515   if (!Opts.MainFileName.empty())
516     Ctx.setMainFileName(StringRef(Opts.MainFileName));
517   Ctx.setDwarfFormat(Opts.Dwarf64 ? dwarf::DWARF64 : dwarf::DWARF32);
518   Ctx.setDwarfVersion(Opts.DwarfVersion);
519   if (Opts.GenDwarfForAssembly)
520     Ctx.setGenDwarfRootFile(Opts.InputFile,
521                             SrcMgr.getMemoryBuffer(BufferIndex)->getBuffer());
522 
523   std::unique_ptr<MCStreamer> Str;
524 
525   std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
526   assert(MCII && "Unable to create instruction info!");
527 
528   raw_pwrite_stream *Out = FDOS.get();
529   std::unique_ptr<buffer_ostream> BOS;
530 
531   MCOptions.MCNoWarn = Opts.NoWarn;
532   MCOptions.MCFatalWarnings = Opts.FatalWarnings;
533   MCOptions.MCNoTypeCheck = Opts.NoTypeCheck;
534   MCOptions.ShowMCInst = Opts.ShowInst;
535   MCOptions.AsmVerbose = true;
536   MCOptions.MCUseDwarfDirectory = MCTargetOptions::EnableDwarfDirectory;
537   MCOptions.ABIName = Opts.TargetABI;
538 
539   // FIXME: There is a bit of code duplication with addPassesToEmitFile.
540   if (Opts.OutputType == AssemblerInvocation::FT_Asm) {
541     MCInstPrinter *IP = TheTarget->createMCInstPrinter(
542         llvm::Triple(Opts.Triple), Opts.OutputAsmVariant, *MAI, *MCII, *MRI);
543 
544     std::unique_ptr<MCCodeEmitter> CE;
545     if (Opts.ShowEncoding)
546       CE.reset(TheTarget->createMCCodeEmitter(*MCII, Ctx));
547     std::unique_ptr<MCAsmBackend> MAB(
548         TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
549 
550     auto FOut = std::make_unique<formatted_raw_ostream>(*Out);
551     Str.reset(TheTarget->createAsmStreamer(Ctx, std::move(FOut), IP,
552                                            std::move(CE), std::move(MAB)));
553   } else if (Opts.OutputType == AssemblerInvocation::FT_Null) {
554     Str.reset(createNullStreamer(Ctx));
555   } else {
556     assert(Opts.OutputType == AssemblerInvocation::FT_Obj &&
557            "Invalid file type!");
558     if (!FDOS->supportsSeeking()) {
559       BOS = std::make_unique<buffer_ostream>(*FDOS);
560       Out = BOS.get();
561     }
562 
563     std::unique_ptr<MCCodeEmitter> CE(
564         TheTarget->createMCCodeEmitter(*MCII, Ctx));
565     std::unique_ptr<MCAsmBackend> MAB(
566         TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
567     assert(MAB && "Unable to create asm backend!");
568 
569     std::unique_ptr<MCObjectWriter> OW =
570         DwoOS ? MAB->createDwoObjectWriter(*Out, *DwoOS)
571               : MAB->createObjectWriter(*Out);
572 
573     Triple T(Opts.Triple);
574     Str.reset(TheTarget->createMCObjectStreamer(
575         T, Ctx, std::move(MAB), std::move(OW), std::move(CE), *STI));
576     Str.get()->initSections(Opts.NoExecStack, *STI);
577   }
578 
579   // When -fembed-bitcode is passed to clang_as, a 1-byte marker
580   // is emitted in __LLVM,__asm section if the object file is MachO format.
581   if (Opts.EmbedBitcode && Ctx.getObjectFileType() == MCContext::IsMachO) {
582     MCSection *AsmLabel = Ctx.getMachOSection(
583         "__LLVM", "__asm", MachO::S_REGULAR, 4, SectionKind::getReadOnly());
584     Str.get()->switchSection(AsmLabel);
585     Str.get()->emitZeros(1);
586   }
587 
588   bool Failed = false;
589 
590   std::unique_ptr<MCAsmParser> Parser(
591       createMCAsmParser(SrcMgr, Ctx, *Str.get(), *MAI));
592 
593   // FIXME: init MCTargetOptions from sanitizer flags here.
594   std::unique_ptr<MCTargetAsmParser> TAP(
595       TheTarget->createMCAsmParser(*STI, *Parser, *MCII, MCOptions));
596   if (!TAP)
597     Failed = Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
598 
599   // Set values for symbols, if any.
600   for (auto &S : Opts.SymbolDefs) {
601     auto Pair = StringRef(S).split('=');
602     auto Sym = Pair.first;
603     auto Val = Pair.second;
604     int64_t Value;
605     // We have already error checked this in the driver.
606     Val.getAsInteger(0, Value);
607     Ctx.setSymbolValue(Parser->getStreamer(), Sym, Value);
608   }
609 
610   if (!Failed) {
611     Parser->setTargetParser(*TAP.get());
612     Failed = Parser->Run(Opts.NoInitialTextSection);
613   }
614 
615   return Failed;
616 }
617 
618 static bool ExecuteAssembler(AssemblerInvocation &Opts,
619                              DiagnosticsEngine &Diags) {
620   bool Failed = ExecuteAssemblerImpl(Opts, Diags);
621 
622   // Delete output file if there were errors.
623   if (Failed) {
624     if (Opts.OutputPath != "-")
625       sys::fs::remove(Opts.OutputPath);
626     if (!Opts.SplitDwarfOutput.empty() && Opts.SplitDwarfOutput != "-")
627       sys::fs::remove(Opts.SplitDwarfOutput);
628   }
629 
630   return Failed;
631 }
632 
633 static void LLVMErrorHandler(void *UserData, const char *Message,
634                              bool GenCrashDiag) {
635   DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
636 
637   Diags.Report(diag::err_fe_error_backend) << Message;
638 
639   // We cannot recover from llvm errors.
640   sys::Process::Exit(1);
641 }
642 
643 int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
644   // Initialize targets and assembly printers/parsers.
645   InitializeAllTargetInfos();
646   InitializeAllTargetMCs();
647   InitializeAllAsmParsers();
648 
649   // Construct our diagnostic client.
650   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
651   TextDiagnosticPrinter *DiagClient
652     = new TextDiagnosticPrinter(errs(), &*DiagOpts);
653   DiagClient->setPrefix("clang -cc1as");
654   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
655   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
656 
657   // Set an error handler, so that any LLVM backend diagnostics go through our
658   // error handler.
659   ScopedFatalErrorHandler FatalErrorHandler
660     (LLVMErrorHandler, static_cast<void*>(&Diags));
661 
662   // Parse the arguments.
663   AssemblerInvocation Asm;
664   if (!AssemblerInvocation::CreateFromArgs(Asm, Argv, Diags))
665     return 1;
666 
667   if (Asm.ShowHelp) {
668     getDriverOptTable().printHelp(
669         llvm::outs(), "clang -cc1as [options] file...",
670         "Clang Integrated Assembler", /*ShowHidden=*/false,
671         /*ShowAllAliases=*/false,
672         llvm::opt::Visibility(driver::options::CC1AsOption));
673 
674     return 0;
675   }
676 
677   // Honor -version.
678   //
679   // FIXME: Use a better -version message?
680   if (Asm.ShowVersion) {
681     llvm::cl::PrintVersionMessage();
682     return 0;
683   }
684 
685   // Honor -mllvm.
686   //
687   // FIXME: Remove this, one day.
688   if (!Asm.LLVMArgs.empty()) {
689     unsigned NumArgs = Asm.LLVMArgs.size();
690     auto Args = std::make_unique<const char*[]>(NumArgs + 2);
691     Args[0] = "clang (LLVM option parsing)";
692     for (unsigned i = 0; i != NumArgs; ++i)
693       Args[i + 1] = Asm.LLVMArgs[i].c_str();
694     Args[NumArgs + 1] = nullptr;
695     llvm::cl::ParseCommandLineOptions(NumArgs + 1, Args.get());
696   }
697 
698   // Execute the invocation, unless there were parsing errors.
699   bool Failed = Diags.hasErrorOccurred() || ExecuteAssembler(Asm, Diags);
700 
701   // If any timers were active but haven't been destroyed yet, print their
702   // results now.
703   TimerGroup::printAll(errs());
704   TimerGroup::clearAll();
705 
706   return !!Failed;
707 }
708