tools/llc/llc.cpp

   1 //===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===//
   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 llc code generator driver. It provides a convenient
  11 // command-line interface for generating native assembly-language code
  12 // or C code, given LLVM bitcode.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/LLVMContext.h"
  17 #include "llvm/Module.h"
  18 #include "llvm/ModuleProvider.h"
  19 #include "llvm/PassManager.h"
  20 #include "llvm/Pass.h"
  21 #include "llvm/ADT/Triple.h"
  22 #include "llvm/Analysis/Verifier.h"
  23 #include "llvm/Support/IRReader.h"
  24 #include "llvm/CodeGen/FileWriters.h"
  25 #include "llvm/CodeGen/LinkAllAsmWriterComponents.h"
  26 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
  27 #include "llvm/CodeGen/ObjectCodeEmitter.h"
  28 #include "llvm/Config/config.h"
  29 #include "llvm/LinkAllVMCore.h"
  30 #include "llvm/Support/CommandLine.h"
  31 #include "llvm/Support/FileUtilities.h"
  32 #include "llvm/Support/FormattedStream.h"
  33 #include "llvm/Support/ManagedStatic.h"
  34 #include "llvm/Support/MemoryBuffer.h"
  35 #include "llvm/Support/PluginLoader.h"
  36 #include "llvm/Support/PrettyStackTrace.h"
  37 #include "llvm/System/Host.h"
  38 #include "llvm/System/Signals.h"
  39 #include "llvm/Target/SubtargetFeature.h"
  40 #include "llvm/Target/TargetData.h"
  41 #include "llvm/Target/TargetMachine.h"
  42 #include "llvm/Target/TargetRegistry.h"
  43 #include "llvm/Target/TargetSelect.h"
  44 #include "llvm/Transforms/Scalar.h"
  45 #include <memory>
  46 using namespace llvm;
  47
  48 // General options for llc.  Other pass-specific options are specified
  49 // within the corresponding llc passes, and target-specific options
  50 // and back-end code generation options are specified with the target machine.
  51 //
  52 static cl::opt<std::string>
  53 InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
  54
  55 static cl::opt<std::string>
  56 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
  57
  58 static cl::opt<bool>
  59 Force("f", cl::desc("Enable binary output on terminals"));
  60
  61 // Determine optimization level.
  62 static cl::opt<char>
  63 OptLevel("O",
  64          cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
  65                   "(default = '-O2')"),
  66          cl::Prefix,
  67          cl::ZeroOrMore,
  68          cl::init(' '));
  69
  70 static cl::opt<std::string>
  71 TargetTriple("mtriple", cl::desc("Override target triple for module"));
  72
  73 static cl::opt<std::string>
  74 MArch("march", cl::desc("Architecture to generate code for (see --version)"));
  75
  76 static cl::opt<std::string>
  77 MCPU("mcpu",
  78   cl::desc("Target a specific cpu type (-mcpu=help for details)"),
  79   cl::value_desc("cpu-name"),
  80   cl::init(""));
  81
  82 static cl::list<std::string>
  83 MAttrs("mattr",
  84   cl::CommaSeparated,
  85   cl::desc("Target specific attributes (-mattr=help for details)"),
  86   cl::value_desc("a1,+a2,-a3,..."));
  87
  88 cl::opt<TargetMachine::CodeGenFileType>
  89 FileType("filetype", cl::init(TargetMachine::AssemblyFile),
  90   cl::desc("Choose a file type (not all types are supported by all targets):"),
  91   cl::values(
  92        clEnumValN(TargetMachine::AssemblyFile, "asm",
  93                   "Emit an assembly ('.s') file"),
  94        clEnumValN(TargetMachine::ObjectFile, "obj",
  95                   "Emit a native object ('.o') file [experimental]"),
  96        clEnumValN(TargetMachine::DynamicLibrary, "dynlib",
  97                   "Emit a native dynamic library ('.so') file"
  98                   " [experimental]"),
  99        clEnumValEnd));
 100
 101 cl::opt<bool> NoVerify("disable-verify", cl::Hidden,
 102                        cl::desc("Do not verify input module"));
 103
 104
 105 static cl::opt<bool>
 106 DisableRedZone("disable-red-zone",
 107   cl::desc("Do not emit code that uses the red zone."),
 108   cl::init(false));
 109
 110 static cl::opt<bool>
 111 NoImplicitFloats("no-implicit-float",
 112   cl::desc("Don't generate implicit floating point instructions (x86-only)"),
 113   cl::init(false));
 114
 115 // GetFileNameRoot - Helper function to get the basename of a filename.
 116 static inline std::string
 117 GetFileNameRoot(const std::string &InputFilename) {
 118   std::string IFN = InputFilename;
 119   std::string outputFilename;
 120   int Len = IFN.length();
 121   if ((Len > 2) &&
 122       IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
 123     outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
 124   } else {
 125     outputFilename = IFN;
 126   }
 127   return outputFilename;
 128 }
 129
 130 static formatted_raw_ostream *GetOutputStream(const char *TargetName,
 131                                               const char *ProgName) {
 132   if (OutputFilename != "") {
 133     if (OutputFilename == "-")
 134       return &fouts();
 135
 136     // Make sure that the Out file gets unlinked from the disk if we get a
 137     // SIGINT
 138     sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 139
 140     std::string error;
 141     raw_fd_ostream *FDOut =
 142       new raw_fd_ostream(OutputFilename.c_str(), error,
 143                          raw_fd_ostream::F_Binary);
 144     if (!error.empty()) {
 145       errs() << error << '\n';
 146       delete FDOut;
 147       return 0;
 148     }
 149     formatted_raw_ostream *Out =
 150       new formatted_raw_ostream(*FDOut, formatted_raw_ostream::DELETE_STREAM);
 151
 152     return Out;
 153   }
 154
 155   if (InputFilename == "-") {
 156     OutputFilename = "-";
 157     return &fouts();
 158   }
 159
 160   OutputFilename = GetFileNameRoot(InputFilename);
 161
 162   bool Binary = false;
 163   switch (FileType) {
 164   case TargetMachine::AssemblyFile:
 165     if (TargetName[0] == 'c') {
 166       if (TargetName[1] == 0)
 167         OutputFilename += ".cbe.c";
 168       else if (TargetName[1] == 'p' && TargetName[2] == 'p')
 169         OutputFilename += ".cpp";
 170       else
 171         OutputFilename += ".s";
 172     } else
 173       OutputFilename += ".s";
 174     break;
 175   case TargetMachine::ObjectFile:
 176     OutputFilename += ".o";
 177     Binary = true;
 178     break;
 179   case TargetMachine::DynamicLibrary:
 180     OutputFilename += LTDL_SHLIB_EXT;
 181     Binary = true;
 182     break;
 183   }
 184
 185   // Make sure that the Out file gets unlinked from the disk if we get a
 186   // SIGINT
 187   sys::RemoveFileOnSignal(sys::Path(OutputFilename));
 188
 189   std::string error;
 190   unsigned OpenFlags = 0;
 191   if (Binary) OpenFlags |= raw_fd_ostream::F_Binary;
 192   raw_fd_ostream *FDOut = new raw_fd_ostream(OutputFilename.c_str(), error,
 193                                              OpenFlags);
 194   if (!error.empty()) {
 195     errs() << error << '\n';
 196     delete FDOut;
 197     return 0;
 198   }
 199
 200   formatted_raw_ostream *Out =
 201     new formatted_raw_ostream(*FDOut, formatted_raw_ostream::DELETE_STREAM);
 202
 203   return Out;
 204 }
 205
 206 // main - Entry point for the llc compiler.
 207 //
 208 int main(int argc, char **argv) {
 209   sys::PrintStackTraceOnErrorSignal();
 210   PrettyStackTraceProgram X(argc, argv);
 211   LLVMContext &Context = getGlobalContext();
 212   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 213
 214   // Initialize targets first, so that --version shows registered targets.
 215   InitializeAllTargets();
 216   InitializeAllAsmPrinters();
 217
 218   cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n");
 219
 220   // Load the module to be compiled...
 221   SMDiagnostic Err;
 222   std::auto_ptr<Module> M;
 223
 224   M.reset(ParseIRFile(InputFilename, Err, Context));
 225   if (M.get() == 0) {
 226     Err.Print(argv[0], errs());
 227     return 1;
 228   }
 229   Module &mod = *M.get();
 230
 231   // If we are supposed to override the target triple, do so now.
 232   if (!TargetTriple.empty())
 233     mod.setTargetTriple(TargetTriple);
 234
 235   Triple TheTriple(mod.getTargetTriple());
 236   if (TheTriple.getTriple().empty())
 237     TheTriple.setTriple(sys::getHostTriple());
 238
 239   // Allocate target machine.  First, check whether the user has explicitly
 240   // specified an architecture to compile for. If so we have to look it up by
 241   // name, because it might be a backend that has no mapping to a target triple.
 242   const Target *TheTarget = 0;
 243   if (!MArch.empty()) {
 244     for (TargetRegistry::iterator it = TargetRegistry::begin(),
 245            ie = TargetRegistry::end(); it != ie; ++it) {
 246       if (MArch == it->getName()) {
 247         TheTarget = &*it;
 248         break;
 249       }
 250     }
 251
 252     if (!TheTarget) {
 253       errs() << argv[0] << ": error: invalid target '" << MArch << "'.\n";
 254       return 1;
 255     }
 256
 257     // Adjust the triple to match (if known), otherwise stick with the
 258     // module/host triple.
 259     Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch);
 260     if (Type != Triple::UnknownArch)
 261       TheTriple.setArch(Type);
 262   } else {
 263     std::string Err;
 264     TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Err);
 265     if (TheTarget == 0) {
 266       errs() << argv[0] << ": error auto-selecting target for module '"
 267              << Err << "'.  Please use the -march option to explicitly "
 268              << "pick a target.\n";
 269       return 1;
 270     }
 271   }
 272
 273   // Package up features to be passed to target/subtarget
 274   std::string FeaturesStr;
 275   if (MCPU.size() || MAttrs.size()) {
 276     SubtargetFeatures Features;
 277     Features.setCPU(MCPU);
 278     for (unsigned i = 0; i != MAttrs.size(); ++i)
 279       Features.AddFeature(MAttrs[i]);
 280     FeaturesStr = Features.getString();
 281   }
 282
 283   std::auto_ptr<TargetMachine>
 284     target(TheTarget->createTargetMachine(TheTriple.getTriple(), FeaturesStr));
 285   assert(target.get() && "Could not allocate target machine!");
 286   TargetMachine &Target = *target.get();
 287
 288   // Figure out where we are going to send the output...
 289   formatted_raw_ostream *Out = GetOutputStream(TheTarget->getName(), argv[0]);
 290   if (Out == 0) return 1;
 291
 292   CodeGenOpt::Level OLvl = CodeGenOpt::Default;
 293   switch (OptLevel) {
 294   default:
 295     errs() << argv[0] << ": invalid optimization level.\n";
 296     return 1;
 297   case ' ': break;
 298   case '0': OLvl = CodeGenOpt::None; break;
 299   case '1':
 300   case '2': OLvl = CodeGenOpt::Default; break;
 301   case '3': OLvl = CodeGenOpt::Aggressive; break;
 302   }
 303
 304   // If this target requires addPassesToEmitWholeFile, do it now.  This is
 305   // used by strange things like the C backend.
 306   if (Target.WantsWholeFile()) {
 307     PassManager PM;
 308
 309     // Add the target data from the target machine, if it exists, or the module.
 310     if (const TargetData *TD = Target.getTargetData())
 311       PM.add(new TargetData(*TD));
 312     else
 313       PM.add(new TargetData(&mod));
 314
 315     if (!NoVerify)
 316       PM.add(createVerifierPass());
 317
 318     // Ask the target to add backend passes as necessary.
 319     if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, OLvl)) {
 320       errs() << argv[0] << ": target does not support generation of this"
 321              << " file type!\n";
 322       if (Out != &fouts()) delete Out;
 323       // And the Out file is empty and useless, so remove it now.
 324       sys::Path(OutputFilename).eraseFromDisk();
 325       return 1;
 326     }
 327     PM.run(mod);
 328   } else {
 329     // Build up all of the passes that we want to do to the module.
 330     ExistingModuleProvider Provider(M.release());
 331     FunctionPassManager Passes(&Provider);
 332
 333     // Add the target data from the target machine, if it exists, or the module.
 334     if (const TargetData *TD = Target.getTargetData())
 335       Passes.add(new TargetData(*TD));
 336     else
 337       Passes.add(new TargetData(&mod));
 338
 339 #ifndef NDEBUG
 340     if (!NoVerify)
 341       Passes.add(createVerifierPass());
 342 #endif
 343
 344     // Ask the target to add backend passes as necessary.
 345     ObjectCodeEmitter *OCE = 0;
 346
 347     // Override default to generate verbose assembly.
 348     Target.setAsmVerbosityDefault(true);
 349
 350     switch (Target.addPassesToEmitFile(Passes, *Out, FileType, OLvl)) {
 351     default:
 352       assert(0 && "Invalid file model!");
 353       return 1;
 354     case FileModel::Error:
 355       errs() << argv[0] << ": target does not support generation of this"
 356              << " file type!\n";
 357       if (Out != &fouts()) delete Out;
 358       // And the Out file is empty and useless, so remove it now.
 359       sys::Path(OutputFilename).eraseFromDisk();
 360       return 1;
 361     case FileModel::AsmFile:
 362       break;
 363     case FileModel::MachOFile:
 364       OCE = AddMachOWriter(Passes, *Out, Target);
 365       break;
 366     case FileModel::ElfFile:
 367       OCE = AddELFWriter(Passes, *Out, Target);
 368       break;
 369     }
 370
 371     if (Target.addPassesToEmitFileFinish(Passes, OCE, OLvl)) {
 372       errs() << argv[0] << ": target does not support generation of this"
 373              << " file type!\n";
 374       if (Out != &fouts()) delete Out;
 375       // And the Out file is empty and useless, so remove it now.
 376       sys::Path(OutputFilename).eraseFromDisk();
 377       return 1;
 378     }
 379
 380     Passes.doInitialization();
 381
 382     // Run our queue of passes all at once now, efficiently.
 383     // TODO: this could lazily stream functions out of the module.
 384     for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I)
 385       if (!I->isDeclaration()) {
 386         if (DisableRedZone)
 387           I->addFnAttr(Attribute::NoRedZone);
 388         if (NoImplicitFloats)
 389           I->addFnAttr(Attribute::NoImplicitFloat);
 390         Passes.run(*I);
 391       }
 392
 393     Passes.doFinalization();
 394   }
 395
 396   // Delete the ostream if it's not a stdout stream
 397   if (Out != &fouts()) delete Out;
 398
 399   return 0;
 400 }