1 //===-lto.cpp - LLVM Link Time Optimizer ----------------------------------===// 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 file implements the Link Time Optimization library. This library is 11 // intended to be used by linker to optimize code at link time. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm-c/lto.h" 16 #include "llvm/CodeGen/CommandFlags.h" 17 #include "llvm/LTO/LTOCodeGenerator.h" 18 #include "llvm/LTO/LTOModule.h" 19 #include "llvm-c/Core.h" 20 #include "llvm-c/Target.h" 21 22 // extra command-line flags needed for LTOCodeGenerator 23 static cl::opt<bool> 24 DisableOpt("disable-opt", cl::init(false), 25 cl::desc("Do not run any optimization passes")); 26 27 static cl::opt<bool> 28 DisableInline("disable-inlining", cl::init(false), 29 cl::desc("Do not run the inliner pass")); 30 31 static cl::opt<bool> 32 DisableGVNLoadPRE("disable-gvn-loadpre", cl::init(false), 33 cl::desc("Do not run the GVN load PRE pass")); 34 35 // Holds most recent error string. 36 // *** Not thread safe *** 37 static std::string sLastErrorString; 38 39 // Holds the initialization state of the LTO module. 40 // *** Not thread safe *** 41 static bool initialized = false; 42 43 // Holds the command-line option parsing state of the LTO module. 44 static bool parsedOptions = false; 45 46 // Initialize the configured targets if they have not been initialized. 47 static void lto_initialize() { 48 if (!initialized) { 49 LLVMInitializeAllTargetInfos(); 50 LLVMInitializeAllTargets(); 51 LLVMInitializeAllTargetMCs(); 52 LLVMInitializeAllAsmParsers(); 53 LLVMInitializeAllAsmPrinters(); 54 LLVMInitializeAllDisassemblers(); 55 initialized = true; 56 } 57 } 58 59 static void lto_set_target_options(llvm::TargetOptions &Options) { 60 Options.LessPreciseFPMADOption = EnableFPMAD; 61 Options.NoFramePointerElim = DisableFPElim; 62 Options.AllowFPOpFusion = FuseFPOps; 63 Options.UnsafeFPMath = EnableUnsafeFPMath; 64 Options.NoInfsFPMath = EnableNoInfsFPMath; 65 Options.NoNaNsFPMath = EnableNoNaNsFPMath; 66 Options.HonorSignDependentRoundingFPMathOption = 67 EnableHonorSignDependentRoundingFPMath; 68 Options.UseSoftFloat = GenerateSoftFloatCalls; 69 if (FloatABIForCalls != llvm::FloatABI::Default) 70 Options.FloatABIType = FloatABIForCalls; 71 Options.NoZerosInBSS = DontPlaceZerosInBSS; 72 Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt; 73 Options.DisableTailCalls = DisableTailCalls; 74 Options.StackAlignmentOverride = OverrideStackAlignment; 75 Options.TrapFuncName = TrapFuncName; 76 Options.PositionIndependentExecutable = EnablePIE; 77 Options.EnableSegmentedStacks = SegmentedStacks; 78 Options.UseInitArray = UseInitArray; 79 } 80 81 /// lto_get_version - Returns a printable string. 82 extern const char* lto_get_version() { 83 return LTOCodeGenerator::getVersionString(); 84 } 85 86 /// lto_get_error_message - Returns the last error string or NULL if last 87 /// operation was successful. 88 const char* lto_get_error_message() { 89 return sLastErrorString.c_str(); 90 } 91 92 /// lto_module_is_object_file - Validates if a file is a loadable object file. 93 bool lto_module_is_object_file(const char* path) { 94 return LTOModule::isBitcodeFile(path); 95 } 96 97 /// lto_module_is_object_file_for_target - Validates if a file is a loadable 98 /// object file compilable for requested target. 99 bool lto_module_is_object_file_for_target(const char* path, 100 const char* target_triplet_prefix) { 101 return LTOModule::isBitcodeFileForTarget(path, target_triplet_prefix); 102 } 103 104 /// lto_module_is_object_file_in_memory - Validates if a buffer is a loadable 105 /// object file. 106 bool lto_module_is_object_file_in_memory(const void* mem, size_t length) { 107 return LTOModule::isBitcodeFile(mem, length); 108 } 109 110 /// lto_module_is_object_file_in_memory_for_target - Validates if a buffer is a 111 /// loadable object file compilable for the target. 112 bool 113 lto_module_is_object_file_in_memory_for_target(const void* mem, 114 size_t length, 115 const char* target_triplet_prefix) { 116 return LTOModule::isBitcodeFileForTarget(mem, length, target_triplet_prefix); 117 } 118 119 /// lto_module_create - Loads an object file from disk. Returns NULL on error 120 /// (check lto_get_error_message() for details). 121 lto_module_t lto_module_create(const char* path) { 122 lto_initialize(); 123 llvm::TargetOptions Options; 124 lto_set_target_options(Options); 125 return LTOModule::makeLTOModule(path, Options, sLastErrorString); 126 } 127 128 /// lto_module_create_from_fd - Loads an object file from disk. Returns NULL on 129 /// error (check lto_get_error_message() for details). 130 lto_module_t lto_module_create_from_fd(int fd, const char *path, size_t size) { 131 lto_initialize(); 132 llvm::TargetOptions Options; 133 lto_set_target_options(Options); 134 return LTOModule::makeLTOModule(fd, path, size, Options, sLastErrorString); 135 } 136 137 /// lto_module_create_from_fd_at_offset - Loads an object file from disk. 138 /// Returns NULL on error (check lto_get_error_message() for details). 139 lto_module_t lto_module_create_from_fd_at_offset(int fd, const char *path, 140 size_t file_size, 141 size_t map_size, 142 off_t offset) { 143 lto_initialize(); 144 llvm::TargetOptions Options; 145 lto_set_target_options(Options); 146 return LTOModule::makeLTOModule(fd, path, map_size, offset, Options, 147 sLastErrorString); 148 } 149 150 /// lto_module_create_from_memory - Loads an object file from memory. Returns 151 /// NULL on error (check lto_get_error_message() for details). 152 lto_module_t lto_module_create_from_memory(const void* mem, size_t length) { 153 lto_initialize(); 154 llvm::TargetOptions Options; 155 lto_set_target_options(Options); 156 return LTOModule::makeLTOModule(mem, length, Options, sLastErrorString); 157 } 158 159 /// lto_module_dispose - Frees all memory for a module. Upon return the 160 /// lto_module_t is no longer valid. 161 void lto_module_dispose(lto_module_t mod) { 162 delete mod; 163 } 164 165 /// lto_module_get_target_triple - Returns triplet string which the object 166 /// module was compiled under. 167 const char* lto_module_get_target_triple(lto_module_t mod) { 168 return mod->getTargetTriple(); 169 } 170 171 /// lto_module_set_target_triple - Sets triple string with which the object will 172 /// be codegened. 173 void lto_module_set_target_triple(lto_module_t mod, const char *triple) { 174 return mod->setTargetTriple(triple); 175 } 176 177 /// lto_module_get_num_symbols - Returns the number of symbols in the object 178 /// module. 179 unsigned int lto_module_get_num_symbols(lto_module_t mod) { 180 return mod->getSymbolCount(); 181 } 182 183 /// lto_module_get_symbol_name - Returns the name of the ith symbol in the 184 /// object module. 185 const char* lto_module_get_symbol_name(lto_module_t mod, unsigned int index) { 186 return mod->getSymbolName(index); 187 } 188 189 /// lto_module_get_symbol_attribute - Returns the attributes of the ith symbol 190 /// in the object module. 191 lto_symbol_attributes lto_module_get_symbol_attribute(lto_module_t mod, 192 unsigned int index) { 193 return mod->getSymbolAttributes(index); 194 } 195 196 /// lto_codegen_create - Instantiates a code generator. Returns NULL if there 197 /// is an error. 198 lto_code_gen_t lto_codegen_create(void) { 199 lto_initialize(); 200 201 TargetOptions Options; 202 lto_set_target_options(Options); 203 204 LTOCodeGenerator *CodeGen = new LTOCodeGenerator(); 205 if (CodeGen) 206 CodeGen->setTargetOptions(Options); 207 return CodeGen; 208 } 209 210 /// lto_codegen_dispose - Frees all memory for a code generator. Upon return the 211 /// lto_code_gen_t is no longer valid. 212 void lto_codegen_dispose(lto_code_gen_t cg) { 213 delete cg; 214 } 215 216 /// lto_codegen_add_module - Add an object module to the set of modules for 217 /// which code will be generated. Returns true on error (check 218 /// lto_get_error_message() for details). 219 bool lto_codegen_add_module(lto_code_gen_t cg, lto_module_t mod) { 220 return !cg->addModule(mod, sLastErrorString); 221 } 222 223 /// lto_codegen_set_debug_model - Sets what if any format of debug info should 224 /// be generated. Returns true on error (check lto_get_error_message() for 225 /// details). 226 bool lto_codegen_set_debug_model(lto_code_gen_t cg, lto_debug_model debug) { 227 cg->setDebugInfo(debug); 228 return false; 229 } 230 231 /// lto_codegen_set_pic_model - Sets what code model to generated. Returns true 232 /// on error (check lto_get_error_message() for details). 233 bool lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model model) { 234 cg->setCodePICModel(model); 235 return false; 236 } 237 238 /// lto_codegen_set_cpu - Sets the cpu to generate code for. 239 void lto_codegen_set_cpu(lto_code_gen_t cg, const char *cpu) { 240 return cg->setCpu(cpu); 241 } 242 243 /// lto_codegen_set_assembler_path - Sets the path to the assembler tool. 244 void lto_codegen_set_assembler_path(lto_code_gen_t cg, const char *path) { 245 // In here only for backwards compatibility. We use MC now. 246 } 247 248 /// lto_codegen_set_assembler_args - Sets extra arguments that libLTO should 249 /// pass to the assembler. 250 void lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args, 251 int nargs) { 252 // In here only for backwards compatibility. We use MC now. 253 } 254 255 /// lto_codegen_add_must_preserve_symbol - Adds to a list of all global symbols 256 /// that must exist in the final generated code. If a function is not listed 257 /// there, it might be inlined into every usage and optimized away. 258 void lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg, 259 const char *symbol) { 260 cg->addMustPreserveSymbol(symbol); 261 } 262 263 /// lto_codegen_write_merged_modules - Writes a new file at the specified path 264 /// that contains the merged contents of all modules added so far. Returns true 265 /// on error (check lto_get_error_message() for details). 266 bool lto_codegen_write_merged_modules(lto_code_gen_t cg, const char *path) { 267 if (!parsedOptions) { 268 cg->parseCodeGenDebugOptions(); 269 parsedOptions = true; 270 } 271 return !cg->writeMergedModules(path, sLastErrorString); 272 } 273 274 /// lto_codegen_compile - Generates code for all added modules into one native 275 /// object file. On success returns a pointer to a generated mach-o/ELF buffer 276 /// and length set to the buffer size. The buffer is owned by the lto_code_gen_t 277 /// object and will be freed when lto_codegen_dispose() is called, or 278 /// lto_codegen_compile() is called again. On failure, returns NULL (check 279 /// lto_get_error_message() for details). 280 const void *lto_codegen_compile(lto_code_gen_t cg, size_t *length) { 281 if (!parsedOptions) { 282 cg->parseCodeGenDebugOptions(); 283 parsedOptions = true; 284 } 285 return cg->compile(length, DisableOpt, DisableInline, DisableGVNLoadPRE, 286 sLastErrorString); 287 } 288 289 /// lto_codegen_compile_to_file - Generates code for all added modules into one 290 /// native object file. The name of the file is written to name. Returns true on 291 /// error. 292 bool lto_codegen_compile_to_file(lto_code_gen_t cg, const char **name) { 293 if (!parsedOptions) { 294 cg->parseCodeGenDebugOptions(); 295 parsedOptions = true; 296 } 297 return !cg->compile_to_file(name, DisableOpt, DisableInline, DisableGVNLoadPRE, 298 sLastErrorString); 299 } 300 301 /// lto_codegen_debug_options - Used to pass extra options to the code 302 /// generator. 303 void lto_codegen_debug_options(lto_code_gen_t cg, const char *opt) { 304 cg->setCodeGenDebugOptions(opt); 305 } 306