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