llc.cpp revision 4b3d57228cae1cba0897b80a73fddd4b8a61894a
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/Bitcode/ReaderWriter.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> 46using 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// 52static cl::opt<std::string> 53InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-")); 54 55static cl::opt<std::string> 56OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename")); 57 58static cl::opt<bool> Force("f", cl::desc("Overwrite output files")); 59 60// Determine optimization level. 61static cl::opt<char> 62OptLevel("O", 63 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] " 64 "(default = '-O2')"), 65 cl::Prefix, 66 cl::ZeroOrMore, 67 cl::init(' ')); 68 69static cl::opt<std::string> 70TargetTriple("mtriple", cl::desc("Override target triple for module")); 71 72static cl::opt<std::string> 73MArch("march", cl::desc("Architecture to generate code for (see --version)")); 74 75static cl::opt<std::string> 76MCPU("mcpu", 77 cl::desc("Target a specific cpu type (-mcpu=help for details)"), 78 cl::value_desc("cpu-name"), 79 cl::init("")); 80 81static cl::list<std::string> 82MAttrs("mattr", 83 cl::CommaSeparated, 84 cl::desc("Target specific attributes (-mattr=help for details)"), 85 cl::value_desc("a1,+a2,-a3,...")); 86 87cl::opt<TargetMachine::CodeGenFileType> 88FileType("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 100cl::opt<bool> NoVerify("disable-verify", cl::Hidden, 101 cl::desc("Do not verify input module")); 102 103 104static cl::opt<bool> 105DisableRedZone("disable-red-zone", 106 cl::desc("Do not emit code that uses the red zone."), 107 cl::init(false)); 108 109static cl::opt<bool> 110NoImplicitFloats("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. 115static inline std::string 116GetFileNameRoot(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 129static formatted_raw_ostream *GetOutputStream(const char *TargetName, 130 const char *ProgName) { 131 if (OutputFilename != "") { 132 if (OutputFilename == "-") 133 return &fouts(); 134 135 // Make sure that the Out file gets unlinked from the disk if we get a 136 // SIGINT 137 sys::RemoveFileOnSignal(sys::Path(OutputFilename)); 138 139 std::string error; 140 raw_fd_ostream *FDOut = new raw_fd_ostream(OutputFilename.c_str(), 141 /*Binary=*/true, Force, error); 142 if (!error.empty()) { 143 errs() << error << '\n'; 144 if (!Force) 145 errs() << "Use -f command line argument to force output\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 raw_fd_ostream *FDOut = new raw_fd_ostream(OutputFilename.c_str(), 191 Binary, Force, error); 192 if (!error.empty()) { 193 errs() << error << '\n'; 194 if (!Force) 195 errs() << "Use -f command line argument to force output\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// 208int 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. 215 InitializeAllTargets(); 216 InitializeAllAsmPrinters(); 217 218 cl::ParseCommandLineOptions(argc, argv, "llvm system compiler\n"); 219 220 // Load the module to be compiled... 221 std::string ErrorMessage; 222 std::auto_ptr<Module> M; 223 224 std::auto_ptr<MemoryBuffer> Buffer( 225 MemoryBuffer::getFileOrSTDIN(InputFilename, &ErrorMessage)); 226 if (Buffer.get()) 227 M.reset(ParseBitcodeFile(Buffer.get(), Context, &ErrorMessage)); 228 if (M.get() == 0) { 229 errs() << argv[0] << ": bitcode didn't read correctly.\n"; 230 errs() << "Reason: " << ErrorMessage << "\n"; 231 return 1; 232 } 233 Module &mod = *M.get(); 234 235 // If we are supposed to override the target triple, do so now. 236 if (!TargetTriple.empty()) 237 mod.setTargetTriple(TargetTriple); 238 239 Triple TheTriple(mod.getTargetTriple()); 240 if (TheTriple.getTriple().empty()) 241 TheTriple.setTriple(sys::getHostTriple()); 242 243 // Allocate target machine. First, check whether the user has explicitly 244 // specified an architecture to compile for. If so we have to look it up by 245 // name, because it might be a backend that has no mapping to a target triple. 246 const Target *TheTarget = 0; 247 if (!MArch.empty()) { 248 for (TargetRegistry::iterator it = TargetRegistry::begin(), 249 ie = TargetRegistry::end(); it != ie; ++it) { 250 if (MArch == it->getName()) { 251 TheTarget = &*it; 252 break; 253 } 254 } 255 256 if (!TheTarget) { 257 errs() << argv[0] << ": error: invalid target '" << MArch << "'.\n"; 258 return 1; 259 } 260 261 // Adjust the triple to match (if known), otherwise stick with the 262 // module/host triple. 263 Triple::ArchType Type = Triple::getArchTypeForLLVMName(MArch); 264 if (Type != Triple::UnknownArch) 265 TheTriple.setArch(Type); 266 } else { 267 std::string Err; 268 TheTarget = TargetRegistry::lookupTarget(TheTriple.getTriple(), Err); 269 if (TheTarget == 0) { 270 errs() << argv[0] << ": error auto-selecting target for module '" 271 << Err << "'. Please use the -march option to explicitly " 272 << "pick a target.\n"; 273 return 1; 274 } 275 } 276 277 // Package up features to be passed to target/subtarget 278 std::string FeaturesStr; 279 if (MCPU.size() || MAttrs.size()) { 280 SubtargetFeatures Features; 281 Features.setCPU(MCPU); 282 for (unsigned i = 0; i != MAttrs.size(); ++i) 283 Features.AddFeature(MAttrs[i]); 284 FeaturesStr = Features.getString(); 285 } 286 287 std::auto_ptr<TargetMachine> 288 target(TheTarget->createTargetMachine(TheTriple.getTriple(), FeaturesStr)); 289 assert(target.get() && "Could not allocate target machine!"); 290 TargetMachine &Target = *target.get(); 291 292 // Figure out where we are going to send the output... 293 formatted_raw_ostream *Out = GetOutputStream(TheTarget->getName(), argv[0]); 294 if (Out == 0) return 1; 295 296 CodeGenOpt::Level OLvl = CodeGenOpt::Default; 297 switch (OptLevel) { 298 default: 299 errs() << argv[0] << ": invalid optimization level.\n"; 300 return 1; 301 case ' ': break; 302 case '0': OLvl = CodeGenOpt::None; break; 303 case '1': 304 case '2': OLvl = CodeGenOpt::Default; break; 305 case '3': OLvl = CodeGenOpt::Aggressive; break; 306 } 307 308 // If this target requires addPassesToEmitWholeFile, do it now. This is 309 // used by strange things like the C backend. 310 if (Target.WantsWholeFile()) { 311 PassManager PM; 312 313 // Add the target data from the target machine, if it exists, or the module. 314 if (const TargetData *TD = Target.getTargetData()) 315 PM.add(new TargetData(*TD)); 316 else 317 PM.add(new TargetData(&mod)); 318 319 if (!NoVerify) 320 PM.add(createVerifierPass()); 321 322 // Ask the target to add backend passes as necessary. 323 if (Target.addPassesToEmitWholeFile(PM, *Out, FileType, OLvl)) { 324 errs() << argv[0] << ": target does not support generation of this" 325 << " file type!\n"; 326 if (Out != &fouts()) delete Out; 327 // And the Out file is empty and useless, so remove it now. 328 sys::Path(OutputFilename).eraseFromDisk(); 329 return 1; 330 } 331 PM.run(mod); 332 } else { 333 // Build up all of the passes that we want to do to the module. 334 ExistingModuleProvider Provider(M.release()); 335 FunctionPassManager Passes(&Provider); 336 337 // Add the target data from the target machine, if it exists, or the module. 338 if (const TargetData *TD = Target.getTargetData()) 339 Passes.add(new TargetData(*TD)); 340 else 341 Passes.add(new TargetData(&mod)); 342 343#ifndef NDEBUG 344 if (!NoVerify) 345 Passes.add(createVerifierPass()); 346#endif 347 348 // Ask the target to add backend passes as necessary. 349 ObjectCodeEmitter *OCE = 0; 350 351 // Override default to generate verbose assembly. 352 Target.setAsmVerbosityDefault(true); 353 354 switch (Target.addPassesToEmitFile(Passes, *Out, FileType, OLvl)) { 355 default: 356 assert(0 && "Invalid file model!"); 357 return 1; 358 case FileModel::Error: 359 errs() << argv[0] << ": target does not support generation of this" 360 << " file type!\n"; 361 if (Out != &fouts()) delete Out; 362 // And the Out file is empty and useless, so remove it now. 363 sys::Path(OutputFilename).eraseFromDisk(); 364 return 1; 365 case FileModel::AsmFile: 366 break; 367 case FileModel::MachOFile: 368 OCE = AddMachOWriter(Passes, *Out, Target); 369 break; 370 case FileModel::ElfFile: 371 OCE = AddELFWriter(Passes, *Out, Target); 372 break; 373 } 374 375 if (Target.addPassesToEmitFileFinish(Passes, OCE, OLvl)) { 376 errs() << argv[0] << ": target does not support generation of this" 377 << " file type!\n"; 378 if (Out != &fouts()) delete Out; 379 // And the Out file is empty and useless, so remove it now. 380 sys::Path(OutputFilename).eraseFromDisk(); 381 return 1; 382 } 383 384 Passes.doInitialization(); 385 386 // Run our queue of passes all at once now, efficiently. 387 // TODO: this could lazily stream functions out of the module. 388 for (Module::iterator I = mod.begin(), E = mod.end(); I != E; ++I) 389 if (!I->isDeclaration()) { 390 if (DisableRedZone) 391 I->addFnAttr(Attribute::NoRedZone); 392 if (NoImplicitFloats) 393 I->addFnAttr(Attribute::NoImplicitFloat); 394 Passes.run(*I); 395 } 396 397 Passes.doFinalization(); 398 } 399 400 Out->flush(); 401 402 // Delete the ostream if it's not a stdout stream 403 if (Out != &fouts()) delete Out; 404 405 return 0; 406} 407