1 //===-- cc1as_main.cpp - Clang Assembler ---------------------------------===//
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 is the entry point to the clang -cc1as functionality, which implements
11 // the direct interface to the LLVM MC based assembler.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "clang/Basic/Diagnostic.h"
16 #include "clang/Basic/DiagnosticOptions.h"
17 #include "clang/Driver/DriverDiagnostic.h"
18 #include "clang/Driver/Options.h"
19 #include "clang/Frontend/FrontendDiagnostic.h"
20 #include "clang/Frontend/TextDiagnosticPrinter.h"
21 #include "clang/Frontend/Utils.h"
22 #include "llvm/ADT/STLExtras.h"
23 #include "llvm/ADT/StringSwitch.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/MC/MCAsmBackend.h"
27 #include "llvm/MC/MCAsmInfo.h"
28 #include "llvm/MC/MCCodeEmitter.h"
29 #include "llvm/MC/MCContext.h"
30 #include "llvm/MC/MCInstrInfo.h"
31 #include "llvm/MC/MCObjectFileInfo.h"
32 #include "llvm/MC/MCParser/MCAsmParser.h"
33 #include "llvm/MC/MCRegisterInfo.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSubtargetInfo.h"
36 #include "llvm/MC/MCTargetAsmParser.h"
37 #include "llvm/MC/MCTargetOptions.h"
38 #include "llvm/Option/Arg.h"
39 #include "llvm/Option/ArgList.h"
40 #include "llvm/Option/OptTable.h"
41 #include "llvm/Support/CommandLine.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/FileSystem.h"
44 #include "llvm/Support/FormattedStream.h"
45 #include "llvm/Support/Host.h"
46 #include "llvm/Support/ManagedStatic.h"
47 #include "llvm/Support/MemoryBuffer.h"
48 #include "llvm/Support/Path.h"
49 #include "llvm/Support/PrettyStackTrace.h"
50 #include "llvm/Support/Signals.h"
51 #include "llvm/Support/SourceMgr.h"
52 #include "llvm/Support/TargetRegistry.h"
53 #include "llvm/Support/TargetSelect.h"
54 #include "llvm/Support/Timer.h"
55 #include "llvm/Support/raw_ostream.h"
56 #include <memory>
57 #include <system_error>
58 using namespace clang;
59 using namespace clang::driver;
60 using namespace clang::driver::options;
61 using namespace llvm;
62 using namespace llvm::opt;
63
64 namespace {
65
66 /// \brief Helper class for representing a single invocation of the assembler.
67 struct AssemblerInvocation {
68 /// @name Target Options
69 /// @{
70
71 /// The name of the target triple to assemble for.
72 std::string Triple;
73
74 /// If given, the name of the target CPU to determine which instructions
75 /// are legal.
76 std::string CPU;
77
78 /// The list of target specific features to enable or disable -- this should
79 /// be a list of strings starting with '+' or '-'.
80 std::vector<std::string> Features;
81
82 /// @}
83 /// @name Language Options
84 /// @{
85
86 std::vector<std::string> IncludePaths;
87 unsigned NoInitialTextSection : 1;
88 unsigned SaveTemporaryLabels : 1;
89 unsigned GenDwarfForAssembly : 1;
90 unsigned CompressDebugSections : 1;
91 unsigned DwarfVersion;
92 std::string DwarfDebugFlags;
93 std::string DwarfDebugProducer;
94 std::string DebugCompilationDir;
95 std::string MainFileName;
96
97 /// @}
98 /// @name Frontend Options
99 /// @{
100
101 std::string InputFile;
102 std::vector<std::string> LLVMArgs;
103 std::string OutputPath;
104 enum FileType {
105 FT_Asm, ///< Assembly (.s) output, transliterate mode.
106 FT_Null, ///< No output, for timing purposes.
107 FT_Obj ///< Object file output.
108 };
109 FileType OutputType;
110 unsigned ShowHelp : 1;
111 unsigned ShowVersion : 1;
112
113 /// @}
114 /// @name Transliterate Options
115 /// @{
116
117 unsigned OutputAsmVariant;
118 unsigned ShowEncoding : 1;
119 unsigned ShowInst : 1;
120
121 /// @}
122 /// @name Assembler Options
123 /// @{
124
125 unsigned RelaxAll : 1;
126 unsigned NoExecStack : 1;
127 unsigned FatalWarnings : 1;
128
129 /// @}
130
131 public:
AssemblerInvocation__anon638d67800111::AssemblerInvocation132 AssemblerInvocation() {
133 Triple = "";
134 NoInitialTextSection = 0;
135 InputFile = "-";
136 OutputPath = "-";
137 OutputType = FT_Asm;
138 OutputAsmVariant = 0;
139 ShowInst = 0;
140 ShowEncoding = 0;
141 RelaxAll = 0;
142 NoExecStack = 0;
143 FatalWarnings = 0;
144 DwarfVersion = 3;
145 }
146
147 static bool CreateFromArgs(AssemblerInvocation &Res,
148 ArrayRef<const char *> Argv,
149 DiagnosticsEngine &Diags);
150 };
151
152 }
153
CreateFromArgs(AssemblerInvocation & Opts,ArrayRef<const char * > Argv,DiagnosticsEngine & Diags)154 bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
155 ArrayRef<const char *> Argv,
156 DiagnosticsEngine &Diags) {
157 bool Success = true;
158
159 // Parse the arguments.
160 std::unique_ptr<OptTable> OptTbl(createDriverOptTable());
161
162 const unsigned IncludedFlagsBitmask = options::CC1AsOption;
163 unsigned MissingArgIndex, MissingArgCount;
164 std::unique_ptr<InputArgList> Args(
165 OptTbl->ParseArgs(Argv.begin(), Argv.end(), MissingArgIndex, MissingArgCount,
166 IncludedFlagsBitmask));
167
168 // Check for missing argument error.
169 if (MissingArgCount) {
170 Diags.Report(diag::err_drv_missing_argument)
171 << Args->getArgString(MissingArgIndex) << MissingArgCount;
172 Success = false;
173 }
174
175 // Issue errors on unknown arguments.
176 for (arg_iterator it = Args->filtered_begin(OPT_UNKNOWN),
177 ie = Args->filtered_end();
178 it != ie; ++it) {
179 Diags.Report(diag::err_drv_unknown_argument) << (*it)->getAsString(*Args);
180 Success = false;
181 }
182
183 // Construct the invocation.
184
185 // Target Options
186 Opts.Triple = llvm::Triple::normalize(Args->getLastArgValue(OPT_triple));
187 Opts.CPU = Args->getLastArgValue(OPT_target_cpu);
188 Opts.Features = Args->getAllArgValues(OPT_target_feature);
189
190 // Use the default target triple if unspecified.
191 if (Opts.Triple.empty())
192 Opts.Triple = llvm::sys::getDefaultTargetTriple();
193
194 // Language Options
195 Opts.IncludePaths = Args->getAllArgValues(OPT_I);
196 Opts.NoInitialTextSection = Args->hasArg(OPT_n);
197 Opts.SaveTemporaryLabels = Args->hasArg(OPT_msave_temp_labels);
198 Opts.GenDwarfForAssembly = Args->hasArg(OPT_g_Flag);
199 Opts.CompressDebugSections = Args->hasArg(OPT_compress_debug_sections);
200 if (Args->hasArg(OPT_gdwarf_2))
201 Opts.DwarfVersion = 2;
202 if (Args->hasArg(OPT_gdwarf_3))
203 Opts.DwarfVersion = 3;
204 if (Args->hasArg(OPT_gdwarf_4))
205 Opts.DwarfVersion = 4;
206 Opts.DwarfDebugFlags = Args->getLastArgValue(OPT_dwarf_debug_flags);
207 Opts.DwarfDebugProducer = Args->getLastArgValue(OPT_dwarf_debug_producer);
208 Opts.DebugCompilationDir = Args->getLastArgValue(OPT_fdebug_compilation_dir);
209 Opts.MainFileName = Args->getLastArgValue(OPT_main_file_name);
210
211 // Frontend Options
212 if (Args->hasArg(OPT_INPUT)) {
213 bool First = true;
214 for (arg_iterator it = Args->filtered_begin(OPT_INPUT),
215 ie = Args->filtered_end(); it != ie; ++it, First=false) {
216 const Arg *A = it;
217 if (First)
218 Opts.InputFile = A->getValue();
219 else {
220 Diags.Report(diag::err_drv_unknown_argument) << A->getAsString(*Args);
221 Success = false;
222 }
223 }
224 }
225 Opts.LLVMArgs = Args->getAllArgValues(OPT_mllvm);
226 Opts.OutputPath = Args->getLastArgValue(OPT_o);
227 if (Arg *A = Args->getLastArg(OPT_filetype)) {
228 StringRef Name = A->getValue();
229 unsigned OutputType = StringSwitch<unsigned>(Name)
230 .Case("asm", FT_Asm)
231 .Case("null", FT_Null)
232 .Case("obj", FT_Obj)
233 .Default(~0U);
234 if (OutputType == ~0U) {
235 Diags.Report(diag::err_drv_invalid_value)
236 << A->getAsString(*Args) << Name;
237 Success = false;
238 } else
239 Opts.OutputType = FileType(OutputType);
240 }
241 Opts.ShowHelp = Args->hasArg(OPT_help);
242 Opts.ShowVersion = Args->hasArg(OPT_version);
243
244 // Transliterate Options
245 Opts.OutputAsmVariant =
246 getLastArgIntValue(*Args.get(), OPT_output_asm_variant, 0, Diags);
247 Opts.ShowEncoding = Args->hasArg(OPT_show_encoding);
248 Opts.ShowInst = Args->hasArg(OPT_show_inst);
249
250 // Assemble Options
251 Opts.RelaxAll = Args->hasArg(OPT_mrelax_all);
252 Opts.NoExecStack = Args->hasArg(OPT_mno_exec_stack);
253 Opts.FatalWarnings = Args->hasArg(OPT_massembler_fatal_warnings);
254
255 return Success;
256 }
257
258 static std::unique_ptr<raw_fd_ostream>
getOutputStream(AssemblerInvocation & Opts,DiagnosticsEngine & Diags,bool Binary)259 getOutputStream(AssemblerInvocation &Opts, DiagnosticsEngine &Diags,
260 bool Binary) {
261 if (Opts.OutputPath.empty())
262 Opts.OutputPath = "-";
263
264 // Make sure that the Out file gets unlinked from the disk if we get a
265 // SIGINT.
266 if (Opts.OutputPath != "-")
267 sys::RemoveFileOnSignal(Opts.OutputPath);
268
269 std::error_code EC;
270 auto Out = llvm::make_unique<raw_fd_ostream>(
271 Opts.OutputPath, EC, (Binary ? sys::fs::F_None : sys::fs::F_Text));
272 if (EC) {
273 Diags.Report(diag::err_fe_unable_to_open_output) << Opts.OutputPath
274 << EC.message();
275 return nullptr;
276 }
277
278 return Out;
279 }
280
ExecuteAssembler(AssemblerInvocation & Opts,DiagnosticsEngine & Diags)281 static bool ExecuteAssembler(AssemblerInvocation &Opts,
282 DiagnosticsEngine &Diags) {
283 // Get the target specific parser.
284 std::string Error;
285 const Target *TheTarget = TargetRegistry::lookupTarget(Opts.Triple, Error);
286 if (!TheTarget)
287 return Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
288
289 ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer =
290 MemoryBuffer::getFileOrSTDIN(Opts.InputFile);
291
292 if (std::error_code EC = Buffer.getError()) {
293 Error = EC.message();
294 return Diags.Report(diag::err_fe_error_reading) << Opts.InputFile;
295 }
296
297 SourceMgr SrcMgr;
298
299 // Tell SrcMgr about this buffer, which is what the parser will pick up.
300 SrcMgr.AddNewSourceBuffer(std::move(*Buffer), SMLoc());
301
302 // Record the location of the include directories so that the lexer can find
303 // it later.
304 SrcMgr.setIncludeDirs(Opts.IncludePaths);
305
306 std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(Opts.Triple));
307 assert(MRI && "Unable to create target register info!");
308
309 std::unique_ptr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, Opts.Triple));
310 assert(MAI && "Unable to create target asm info!");
311
312 // Ensure MCAsmInfo initialization occurs before any use, otherwise sections
313 // may be created with a combination of default and explicit settings.
314 if (Opts.CompressDebugSections)
315 MAI->setCompressDebugSections(true);
316
317 bool IsBinary = Opts.OutputType == AssemblerInvocation::FT_Obj;
318 std::unique_ptr<raw_fd_ostream> FDOS = getOutputStream(Opts, Diags, IsBinary);
319 if (!FDOS)
320 return true;
321
322 // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
323 // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
324 std::unique_ptr<MCObjectFileInfo> MOFI(new MCObjectFileInfo());
325
326 MCContext Ctx(MAI.get(), MRI.get(), MOFI.get(), &SrcMgr);
327 // FIXME: Assembler behavior can change with -static.
328 MOFI->InitMCObjectFileInfo(Opts.Triple,
329 Reloc::Default, CodeModel::Default, Ctx);
330 if (Opts.SaveTemporaryLabels)
331 Ctx.setAllowTemporaryLabels(false);
332 if (Opts.GenDwarfForAssembly)
333 Ctx.setGenDwarfForAssembly(true);
334 if (!Opts.DwarfDebugFlags.empty())
335 Ctx.setDwarfDebugFlags(StringRef(Opts.DwarfDebugFlags));
336 if (!Opts.DwarfDebugProducer.empty())
337 Ctx.setDwarfDebugProducer(StringRef(Opts.DwarfDebugProducer));
338 if (!Opts.DebugCompilationDir.empty())
339 Ctx.setCompilationDir(Opts.DebugCompilationDir);
340 if (!Opts.MainFileName.empty())
341 Ctx.setMainFileName(StringRef(Opts.MainFileName));
342 Ctx.setDwarfVersion(Opts.DwarfVersion);
343
344 // Build up the feature string from the target feature list.
345 std::string FS;
346 if (!Opts.Features.empty()) {
347 FS = Opts.Features[0];
348 for (unsigned i = 1, e = Opts.Features.size(); i != e; ++i)
349 FS += "," + Opts.Features[i];
350 }
351
352 std::unique_ptr<MCStreamer> Str;
353
354 std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
355 std::unique_ptr<MCSubtargetInfo> STI(
356 TheTarget->createMCSubtargetInfo(Opts.Triple, Opts.CPU, FS));
357
358 raw_pwrite_stream *Out = FDOS.get();
359 std::unique_ptr<buffer_ostream> BOS;
360
361 // FIXME: There is a bit of code duplication with addPassesToEmitFile.
362 if (Opts.OutputType == AssemblerInvocation::FT_Asm) {
363 MCInstPrinter *IP = TheTarget->createMCInstPrinter(
364 llvm::Triple(Opts.Triple), Opts.OutputAsmVariant, *MAI, *MCII, *MRI);
365 MCCodeEmitter *CE = nullptr;
366 MCAsmBackend *MAB = nullptr;
367 if (Opts.ShowEncoding) {
368 CE = TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx);
369 MAB = TheTarget->createMCAsmBackend(*MRI, Opts.Triple, Opts.CPU);
370 }
371 auto FOut = llvm::make_unique<formatted_raw_ostream>(*Out);
372 Str.reset(TheTarget->createAsmStreamer(
373 Ctx, std::move(FOut), /*asmverbose*/ true,
374 /*useDwarfDirectory*/ true, IP, CE, MAB, Opts.ShowInst));
375 } else if (Opts.OutputType == AssemblerInvocation::FT_Null) {
376 Str.reset(createNullStreamer(Ctx));
377 } else {
378 assert(Opts.OutputType == AssemblerInvocation::FT_Obj &&
379 "Invalid file type!");
380 if (!FDOS->supportsSeeking()) {
381 BOS = make_unique<buffer_ostream>(*FDOS);
382 Out = BOS.get();
383 }
384
385 MCCodeEmitter *CE = TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx);
386 MCAsmBackend *MAB = TheTarget->createMCAsmBackend(*MRI, Opts.Triple,
387 Opts.CPU);
388 Triple T(Opts.Triple);
389 Str.reset(TheTarget->createMCObjectStreamer(T, Ctx, *MAB, *Out, CE, *STI,
390 Opts.RelaxAll,
391 /*DWARFMustBeAtTheEnd*/ true));
392 Str.get()->InitSections(Opts.NoExecStack);
393 }
394
395 bool Failed = false;
396
397 std::unique_ptr<MCAsmParser> Parser(
398 createMCAsmParser(SrcMgr, Ctx, *Str.get(), *MAI));
399
400 // FIXME: init MCTargetOptions from sanitizer flags here.
401 MCTargetOptions Options;
402 std::unique_ptr<MCTargetAsmParser> TAP(
403 TheTarget->createMCAsmParser(*STI, *Parser, *MCII, Options));
404 if (!TAP)
405 Failed = Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
406
407 if (!Failed) {
408 Parser->setTargetParser(*TAP.get());
409 Failed = Parser->Run(Opts.NoInitialTextSection);
410 }
411
412 // Close the output stream early.
413 BOS.reset();
414 FDOS.reset();
415
416 // Delete output file if there were errors.
417 if (Failed && Opts.OutputPath != "-")
418 sys::fs::remove(Opts.OutputPath);
419
420 return Failed;
421 }
422
LLVMErrorHandler(void * UserData,const std::string & Message,bool GenCrashDiag)423 static void LLVMErrorHandler(void *UserData, const std::string &Message,
424 bool GenCrashDiag) {
425 DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
426
427 Diags.Report(diag::err_fe_error_backend) << Message;
428
429 // We cannot recover from llvm errors.
430 exit(1);
431 }
432
cc1as_main(ArrayRef<const char * > Argv,const char * Argv0,void * MainAddr)433 int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
434 // Print a stack trace if we signal out.
435 sys::PrintStackTraceOnErrorSignal();
436 PrettyStackTraceProgram X(Argv.size(), Argv.data());
437 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
438
439 // Initialize targets and assembly printers/parsers.
440 InitializeAllTargetInfos();
441 InitializeAllTargetMCs();
442 InitializeAllAsmParsers();
443
444 // Construct our diagnostic client.
445 IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
446 TextDiagnosticPrinter *DiagClient
447 = new TextDiagnosticPrinter(errs(), &*DiagOpts);
448 DiagClient->setPrefix("clang -cc1as");
449 IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
450 DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
451
452 // Set an error handler, so that any LLVM backend diagnostics go through our
453 // error handler.
454 ScopedFatalErrorHandler FatalErrorHandler
455 (LLVMErrorHandler, static_cast<void*>(&Diags));
456
457 // Parse the arguments.
458 AssemblerInvocation Asm;
459 if (!AssemblerInvocation::CreateFromArgs(Asm, Argv, Diags))
460 return 1;
461
462 if (Asm.ShowHelp) {
463 std::unique_ptr<OptTable> Opts(driver::createDriverOptTable());
464 Opts->PrintHelp(llvm::outs(), "clang -cc1as", "Clang Integrated Assembler",
465 /*Include=*/driver::options::CC1AsOption, /*Exclude=*/0);
466 return 0;
467 }
468
469 // Honor -version.
470 //
471 // FIXME: Use a better -version message?
472 if (Asm.ShowVersion) {
473 llvm::cl::PrintVersionMessage();
474 return 0;
475 }
476
477 // Honor -mllvm.
478 //
479 // FIXME: Remove this, one day.
480 if (!Asm.LLVMArgs.empty()) {
481 unsigned NumArgs = Asm.LLVMArgs.size();
482 const char **Args = new const char*[NumArgs + 2];
483 Args[0] = "clang (LLVM option parsing)";
484 for (unsigned i = 0; i != NumArgs; ++i)
485 Args[i + 1] = Asm.LLVMArgs[i].c_str();
486 Args[NumArgs + 1] = nullptr;
487 llvm::cl::ParseCommandLineOptions(NumArgs + 1, Args);
488 }
489
490 // Execute the invocation, unless there were parsing errors.
491 bool Failed = Diags.hasErrorOccurred() || ExecuteAssembler(Asm, Diags);
492
493 // If any timers were active but haven't been destroyed yet, print their
494 // results now.
495 TimerGroup::printAll(errs());
496
497 return !!Failed;
498 }
499
500