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