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