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/Driver/Arg.h"
17 #include "clang/Driver/ArgList.h"
18 #include "clang/Driver/DriverDiagnostic.h"
19 #include "clang/Driver/CC1AsOptions.h"
20 #include "clang/Driver/OptTable.h"
21 #include "clang/Driver/Options.h"
22 #include "clang/Frontend/DiagnosticOptions.h"
23 #include "clang/Frontend/FrontendDiagnostic.h"
24 #include "clang/Frontend/TextDiagnosticPrinter.h"
25 #include "llvm/ADT/OwningPtr.h"
26 #include "llvm/ADT/StringSwitch.h"
27 #include "llvm/ADT/Triple.h"
28 #include "llvm/MC/MCParser/MCAsmParser.h"
29 #include "llvm/MC/MCAsmInfo.h"
30 #include "llvm/MC/MCCodeEmitter.h"
31 #include "llvm/MC/MCContext.h"
32 #include "llvm/MC/MCInstrInfo.h"
33 #include "llvm/MC/MCObjectFileInfo.h"
34 #include "llvm/MC/MCRegisterInfo.h"
35 #include "llvm/MC/MCStreamer.h"
36 #include "llvm/MC/MCSubtargetInfo.h"
37 #include "llvm/MC/MCAsmBackend.h"
38 #include "llvm/MC/MCTargetAsmParser.h"
39 #include "llvm/Support/CommandLine.h"
40 #include "llvm/Support/FormattedStream.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/ManagedStatic.h"
43 #include "llvm/Support/MemoryBuffer.h"
44 #include "llvm/Support/PrettyStackTrace.h"
45 #include "llvm/Support/SourceMgr.h"
46 #include "llvm/Support/Host.h"
47 #include "llvm/Support/Path.h"
48 #include "llvm/Support/Signals.h"
49 #include "llvm/Support/TargetRegistry.h"
50 #include "llvm/Support/TargetSelect.h"
51 #include "llvm/Support/Timer.h"
52 #include "llvm/Support/raw_ostream.h"
53 #include "llvm/Support/system_error.h"
54 #include "llvm/Target/TargetData.h"
55 using namespace clang;
56 using namespace clang::driver;
57 using namespace llvm;
58 
59 namespace {
60 
61 /// \brief Helper class for representing a single invocation of the assembler.
62 struct AssemblerInvocation {
63   /// @name Target Options
64   /// @{
65 
66   std::string Triple;
67 
68   /// @}
69   /// @name Language Options
70   /// @{
71 
72   std::vector<std::string> IncludePaths;
73   unsigned NoInitialTextSection : 1;
74   unsigned SaveTemporaryLabels : 1;
75 
76   /// @}
77   /// @name Frontend Options
78   /// @{
79 
80   std::string InputFile;
81   std::vector<std::string> LLVMArgs;
82   std::string OutputPath;
83   enum FileType {
84     FT_Asm,  ///< Assembly (.s) output, transliterate mode.
85     FT_Null, ///< No output, for timing purposes.
86     FT_Obj   ///< Object file output.
87   };
88   FileType OutputType;
89   unsigned ShowHelp : 1;
90   unsigned ShowVersion : 1;
91 
92   /// @}
93   /// @name Transliterate Options
94   /// @{
95 
96   unsigned OutputAsmVariant;
97   unsigned ShowEncoding : 1;
98   unsigned ShowInst : 1;
99 
100   /// @}
101   /// @name Assembler Options
102   /// @{
103 
104   unsigned RelaxAll : 1;
105   unsigned NoExecStack : 1;
106 
107   /// @}
108 
109 public:
110   AssemblerInvocation() {
111     Triple = "";
112     NoInitialTextSection = 0;
113     InputFile = "-";
114     OutputPath = "-";
115     OutputType = FT_Asm;
116     OutputAsmVariant = 0;
117     ShowInst = 0;
118     ShowEncoding = 0;
119     RelaxAll = 0;
120     NoExecStack = 0;
121   }
122 
123   static void CreateFromArgs(AssemblerInvocation &Res, const char **ArgBegin,
124                              const char **ArgEnd, DiagnosticsEngine &Diags);
125 };
126 
127 }
128 
129 void AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
130                                          const char **ArgBegin,
131                                          const char **ArgEnd,
132                                          DiagnosticsEngine &Diags) {
133   using namespace clang::driver::cc1asoptions;
134   // Parse the arguments.
135   OwningPtr<OptTable> OptTbl(createCC1AsOptTable());
136   unsigned MissingArgIndex, MissingArgCount;
137   OwningPtr<InputArgList> Args(
138     OptTbl->ParseArgs(ArgBegin, ArgEnd,MissingArgIndex, MissingArgCount));
139 
140   // Check for missing argument error.
141   if (MissingArgCount)
142     Diags.Report(diag::err_drv_missing_argument)
143       << Args->getArgString(MissingArgIndex) << MissingArgCount;
144 
145   // Issue errors on unknown arguments.
146   for (arg_iterator it = Args->filtered_begin(cc1asoptions::OPT_UNKNOWN),
147          ie = Args->filtered_end(); it != ie; ++it)
148     Diags.Report(diag::err_drv_unknown_argument) << (*it) ->getAsString(*Args);
149 
150   // Construct the invocation.
151 
152   // Target Options
153   Opts.Triple = Triple::normalize(Args->getLastArgValue(OPT_triple));
154   if (Opts.Triple.empty()) // Use the default target triple if unspecified.
155     Opts.Triple = sys::getDefaultTargetTriple();
156 
157   // Language Options
158   Opts.IncludePaths = Args->getAllArgValues(OPT_I);
159   Opts.NoInitialTextSection = Args->hasArg(OPT_n);
160   Opts.SaveTemporaryLabels = Args->hasArg(OPT_L);
161 
162   // Frontend Options
163   if (Args->hasArg(OPT_INPUT)) {
164     bool First = true;
165     for (arg_iterator it = Args->filtered_begin(OPT_INPUT),
166            ie = Args->filtered_end(); it != ie; ++it, First=false) {
167       const Arg *A = it;
168       if (First)
169         Opts.InputFile = A->getValue(*Args);
170       else
171         Diags.Report(diag::err_drv_unknown_argument) << A->getAsString(*Args);
172     }
173   }
174   Opts.LLVMArgs = Args->getAllArgValues(OPT_mllvm);
175   if (Args->hasArg(OPT_fatal_warnings))
176     Opts.LLVMArgs.push_back("-fatal-assembler-warnings");
177   Opts.OutputPath = Args->getLastArgValue(OPT_o);
178   if (Arg *A = Args->getLastArg(OPT_filetype)) {
179     StringRef Name = A->getValue(*Args);
180     unsigned OutputType = StringSwitch<unsigned>(Name)
181       .Case("asm", FT_Asm)
182       .Case("null", FT_Null)
183       .Case("obj", FT_Obj)
184       .Default(~0U);
185     if (OutputType == ~0U)
186       Diags.Report(diag::err_drv_invalid_value)
187         << A->getAsString(*Args) << Name;
188     else
189       Opts.OutputType = FileType(OutputType);
190   }
191   Opts.ShowHelp = Args->hasArg(OPT_help);
192   Opts.ShowVersion = Args->hasArg(OPT_version);
193 
194   // Transliterate Options
195   Opts.OutputAsmVariant = Args->getLastArgIntValue(OPT_output_asm_variant,
196                                                    0, Diags);
197   Opts.ShowEncoding = Args->hasArg(OPT_show_encoding);
198   Opts.ShowInst = Args->hasArg(OPT_show_inst);
199 
200   // Assemble Options
201   Opts.RelaxAll = Args->hasArg(OPT_relax_all);
202   Opts.NoExecStack =  Args->hasArg(OPT_no_exec_stack);
203 }
204 
205 static formatted_raw_ostream *GetOutputStream(AssemblerInvocation &Opts,
206                                               DiagnosticsEngine &Diags,
207                                               bool Binary) {
208   if (Opts.OutputPath.empty())
209     Opts.OutputPath = "-";
210 
211   // Make sure that the Out file gets unlinked from the disk if we get a
212   // SIGINT.
213   if (Opts.OutputPath != "-")
214     sys::RemoveFileOnSignal(sys::Path(Opts.OutputPath));
215 
216   std::string Error;
217   raw_fd_ostream *Out =
218     new raw_fd_ostream(Opts.OutputPath.c_str(), Error,
219                        (Binary ? raw_fd_ostream::F_Binary : 0));
220   if (!Error.empty()) {
221     Diags.Report(diag::err_fe_unable_to_open_output)
222       << Opts.OutputPath << Error;
223     return 0;
224   }
225 
226   return new formatted_raw_ostream(*Out, formatted_raw_ostream::DELETE_STREAM);
227 }
228 
229 static bool ExecuteAssembler(AssemblerInvocation &Opts,
230                              DiagnosticsEngine &Diags) {
231   // Get the target specific parser.
232   std::string Error;
233   const Target *TheTarget(TargetRegistry::lookupTarget(Opts.Triple, Error));
234   if (!TheTarget) {
235     Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
236     return false;
237   }
238 
239   OwningPtr<MemoryBuffer> BufferPtr;
240   if (error_code ec = MemoryBuffer::getFileOrSTDIN(Opts.InputFile, BufferPtr)) {
241     Error = ec.message();
242     Diags.Report(diag::err_fe_error_reading) << Opts.InputFile;
243     return false;
244   }
245   MemoryBuffer *Buffer = BufferPtr.take();
246 
247   SourceMgr SrcMgr;
248 
249   // Tell SrcMgr about this buffer, which is what the parser will pick up.
250   SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());
251 
252   // Record the location of the include directories so that the lexer can find
253   // it later.
254   SrcMgr.setIncludeDirs(Opts.IncludePaths);
255 
256   OwningPtr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(Opts.Triple));
257   assert(MAI && "Unable to create target asm info!");
258 
259   OwningPtr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(Opts.Triple));
260   assert(MRI && "Unable to create target register info!");
261 
262   bool IsBinary = Opts.OutputType == AssemblerInvocation::FT_Obj;
263   formatted_raw_ostream *Out = GetOutputStream(Opts, Diags, IsBinary);
264   if (!Out)
265     return false;
266 
267   // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
268   // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
269   OwningPtr<MCObjectFileInfo> MOFI(new MCObjectFileInfo());
270   MCContext Ctx(*MAI, *MRI, MOFI.get());
271   // FIXME: Assembler behavior can change with -static.
272   MOFI->InitMCObjectFileInfo(Opts.Triple,
273                              Reloc::Default, CodeModel::Default, Ctx);
274   if (Opts.SaveTemporaryLabels)
275     Ctx.setAllowTemporaryLabels(false);
276 
277   OwningPtr<MCStreamer> Str;
278 
279   OwningPtr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
280   OwningPtr<MCSubtargetInfo>
281     STI(TheTarget->createMCSubtargetInfo(Opts.Triple, "", ""));
282 
283   // FIXME: There is a bit of code duplication with addPassesToEmitFile.
284   if (Opts.OutputType == AssemblerInvocation::FT_Asm) {
285     MCInstPrinter *IP =
286       TheTarget->createMCInstPrinter(Opts.OutputAsmVariant, *MAI, *STI);
287     MCCodeEmitter *CE = 0;
288     MCAsmBackend *MAB = 0;
289     if (Opts.ShowEncoding) {
290       CE = TheTarget->createMCCodeEmitter(*MCII, *STI, Ctx);
291       MAB = TheTarget->createMCAsmBackend(Opts.Triple);
292     }
293     Str.reset(TheTarget->createAsmStreamer(Ctx, *Out, /*asmverbose*/true,
294                                            /*useLoc*/ true,
295                                            /*useCFI*/ true,
296                                            /*useDwarfDirectory*/ true,
297                                            IP, CE, MAB,
298                                            Opts.ShowInst));
299   } else if (Opts.OutputType == AssemblerInvocation::FT_Null) {
300     Str.reset(createNullStreamer(Ctx));
301   } else {
302     assert(Opts.OutputType == AssemblerInvocation::FT_Obj &&
303            "Invalid file type!");
304     MCCodeEmitter *CE = TheTarget->createMCCodeEmitter(*MCII, *STI, Ctx);
305     MCAsmBackend *MAB = TheTarget->createMCAsmBackend(Opts.Triple);
306     Str.reset(TheTarget->createMCObjectStreamer(Opts.Triple, Ctx, *MAB, *Out,
307                                                 CE, Opts.RelaxAll,
308                                                 Opts.NoExecStack));
309     Str.get()->InitSections();
310   }
311 
312   OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr, Ctx,
313                                                   *Str.get(), *MAI));
314   OwningPtr<MCTargetAsmParser> TAP(TheTarget->createMCAsmParser(*STI, *Parser));
315   if (!TAP) {
316     Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
317     return false;
318   }
319 
320   Parser->setTargetParser(*TAP.get());
321 
322   bool Success = !Parser->Run(Opts.NoInitialTextSection);
323 
324   // Close the output.
325   delete Out;
326 
327   // Delete output on errors.
328   if (!Success && Opts.OutputPath != "-")
329     sys::Path(Opts.OutputPath).eraseFromDisk();
330 
331   return Success;
332 }
333 
334 static void LLVMErrorHandler(void *UserData, const std::string &Message) {
335   DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
336 
337   Diags.Report(diag::err_fe_error_backend) << Message;
338 
339   // We cannot recover from llvm errors.
340   exit(1);
341 }
342 
343 int cc1as_main(const char **ArgBegin, const char **ArgEnd,
344                const char *Argv0, void *MainAddr) {
345   // Print a stack trace if we signal out.
346   sys::PrintStackTraceOnErrorSignal();
347   PrettyStackTraceProgram X(ArgEnd - ArgBegin, ArgBegin);
348   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
349 
350   // Initialize targets and assembly printers/parsers.
351   InitializeAllTargetInfos();
352   InitializeAllTargetMCs();
353   InitializeAllAsmParsers();
354 
355   // Construct our diagnostic client.
356   TextDiagnosticPrinter *DiagClient
357     = new TextDiagnosticPrinter(errs(), DiagnosticOptions());
358   DiagClient->setPrefix("clang -cc1as");
359   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
360   DiagnosticsEngine Diags(DiagID, DiagClient);
361 
362   // Set an error handler, so that any LLVM backend diagnostics go through our
363   // error handler.
364   ScopedFatalErrorHandler FatalErrorHandler
365     (LLVMErrorHandler, static_cast<void*>(&Diags));
366 
367   // Parse the arguments.
368   AssemblerInvocation Asm;
369   AssemblerInvocation::CreateFromArgs(Asm, ArgBegin, ArgEnd, Diags);
370 
371   // Honor -help.
372   if (Asm.ShowHelp) {
373     llvm::OwningPtr<driver::OptTable> Opts(driver::createCC1AsOptTable());
374     Opts->PrintHelp(llvm::outs(), "clang -cc1as", "Clang Integrated Assembler");
375     return 0;
376   }
377 
378   // Honor -version.
379   //
380   // FIXME: Use a better -version message?
381   if (Asm.ShowVersion) {
382     llvm::cl::PrintVersionMessage();
383     return 0;
384   }
385 
386   // Honor -mllvm.
387   //
388   // FIXME: Remove this, one day.
389   if (!Asm.LLVMArgs.empty()) {
390     unsigned NumArgs = Asm.LLVMArgs.size();
391     const char **Args = new const char*[NumArgs + 2];
392     Args[0] = "clang (LLVM option parsing)";
393     for (unsigned i = 0; i != NumArgs; ++i)
394       Args[i + 1] = Asm.LLVMArgs[i].c_str();
395     Args[NumArgs + 1] = 0;
396     llvm::cl::ParseCommandLineOptions(NumArgs + 1, const_cast<char **>(Args));
397   }
398 
399   // Execute the invocation, unless there were parsing errors.
400   bool Success = false;
401   if (!Diags.hasErrorOccurred())
402     Success = ExecuteAssembler(Asm, Diags);
403 
404   // If any timers were active but haven't been destroyed yet, print their
405   // results now.
406   TimerGroup::printAll(errs());
407 
408   return !Success;
409 }
410