lto.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338
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-c/Core.h" 17#include "llvm-c/Target.h" 18#include "llvm/CodeGen/CommandFlags.h" 19#include "llvm/LTO/LTOCodeGenerator.h" 20#include "llvm/LTO/LTOModule.h" 21 22// extra command-line flags needed for LTOCodeGenerator 23static cl::opt<bool> 24DisableOpt("disable-opt", cl::init(false), 25 cl::desc("Do not run any optimization passes")); 26 27static cl::opt<bool> 28DisableInline("disable-inlining", cl::init(false), 29 cl::desc("Do not run the inliner pass")); 30 31static cl::opt<bool> 32DisableGVNLoadPRE("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 *** 37static std::string sLastErrorString; 38 39// Holds the initialization state of the LTO module. 40// *** Not thread safe *** 41static bool initialized = false; 42 43// Holds the command-line option parsing state of the LTO module. 44static bool parsedOptions = false; 45 46// Initialize the configured targets if they have not been initialized. 47static 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/// lto_get_version - Returns a printable string. 60extern const char* lto_get_version() { 61 return LTOCodeGenerator::getVersionString(); 62} 63 64/// lto_get_error_message - Returns the last error string or NULL if last 65/// operation was successful. 66const char* lto_get_error_message() { 67 return sLastErrorString.c_str(); 68} 69 70/// lto_module_is_object_file - Validates if a file is a loadable object file. 71bool lto_module_is_object_file(const char* path) { 72 return LTOModule::isBitcodeFile(path); 73} 74 75/// lto_module_is_object_file_for_target - Validates if a file is a loadable 76/// object file compilable for requested target. 77bool lto_module_is_object_file_for_target(const char* path, 78 const char* target_triplet_prefix) { 79 return LTOModule::isBitcodeFileForTarget(path, target_triplet_prefix); 80} 81 82/// lto_module_is_object_file_in_memory - Validates if a buffer is a loadable 83/// object file. 84bool lto_module_is_object_file_in_memory(const void* mem, size_t length) { 85 return LTOModule::isBitcodeFile(mem, length); 86} 87 88/// lto_module_is_object_file_in_memory_for_target - Validates if a buffer is a 89/// loadable object file compilable for the target. 90bool 91lto_module_is_object_file_in_memory_for_target(const void* mem, 92 size_t length, 93 const char* target_triplet_prefix) { 94 return LTOModule::isBitcodeFileForTarget(mem, length, target_triplet_prefix); 95} 96 97/// lto_module_create - Loads an object file from disk. Returns NULL on error 98/// (check lto_get_error_message() for details). 99lto_module_t lto_module_create(const char* path) { 100 lto_initialize(); 101 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); 102 return LTOModule::makeLTOModule(path, Options, sLastErrorString); 103} 104 105/// lto_module_create_from_fd - Loads an object file from disk. Returns NULL on 106/// error (check lto_get_error_message() for details). 107lto_module_t lto_module_create_from_fd(int fd, const char *path, size_t size) { 108 lto_initialize(); 109 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); 110 return LTOModule::makeLTOModule(fd, path, size, Options, sLastErrorString); 111} 112 113/// lto_module_create_from_fd_at_offset - Loads an object file from disk. 114/// Returns NULL on error (check lto_get_error_message() for details). 115lto_module_t lto_module_create_from_fd_at_offset(int fd, const char *path, 116 size_t file_size, 117 size_t map_size, 118 off_t offset) { 119 lto_initialize(); 120 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); 121 return LTOModule::makeLTOModule(fd, path, map_size, offset, Options, 122 sLastErrorString); 123} 124 125/// lto_module_create_from_memory - Loads an object file from memory. Returns 126/// NULL on error (check lto_get_error_message() for details). 127lto_module_t lto_module_create_from_memory(const void* mem, size_t length) { 128 lto_initialize(); 129 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); 130 return LTOModule::makeLTOModule(mem, length, Options, sLastErrorString); 131} 132 133/// Loads an object file from memory with an extra path argument. 134/// Returns NULL on error (check lto_get_error_message() for details). 135lto_module_t lto_module_create_from_memory_with_path(const void* mem, 136 size_t length, 137 const char *path) { 138 lto_initialize(); 139 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); 140 return LTOModule::makeLTOModule(mem, length, Options, sLastErrorString, path); 141} 142 143/// lto_module_dispose - Frees all memory for a module. Upon return the 144/// lto_module_t is no longer valid. 145void lto_module_dispose(lto_module_t mod) { 146 delete mod; 147} 148 149/// lto_module_get_target_triple - Returns triplet string which the object 150/// module was compiled under. 151const char* lto_module_get_target_triple(lto_module_t mod) { 152 return mod->getTargetTriple(); 153} 154 155/// lto_module_set_target_triple - Sets triple string with which the object will 156/// be codegened. 157void lto_module_set_target_triple(lto_module_t mod, const char *triple) { 158 return mod->setTargetTriple(triple); 159} 160 161/// lto_module_get_num_symbols - Returns the number of symbols in the object 162/// module. 163unsigned int lto_module_get_num_symbols(lto_module_t mod) { 164 return mod->getSymbolCount(); 165} 166 167/// lto_module_get_symbol_name - Returns the name of the ith symbol in the 168/// object module. 169const char* lto_module_get_symbol_name(lto_module_t mod, unsigned int index) { 170 return mod->getSymbolName(index); 171} 172 173/// lto_module_get_symbol_attribute - Returns the attributes of the ith symbol 174/// in the object module. 175lto_symbol_attributes lto_module_get_symbol_attribute(lto_module_t mod, 176 unsigned int index) { 177 return mod->getSymbolAttributes(index); 178} 179 180/// lto_module_get_num_deplibs - Returns the number of dependent libraries in 181/// the object module. 182unsigned int lto_module_get_num_deplibs(lto_module_t mod) { 183 return mod->getDependentLibraryCount(); 184} 185 186/// lto_module_get_deplib - Returns the ith dependent library in the module. 187const char* lto_module_get_deplib(lto_module_t mod, unsigned int index) { 188 return mod->getDependentLibrary(index); 189} 190 191/// lto_module_get_num_linkeropts - Returns the number of linker options in the 192/// object module. 193unsigned int lto_module_get_num_linkeropts(lto_module_t mod) { 194 return mod->getLinkerOptCount(); 195} 196 197/// lto_module_get_linkeropt - Returns the ith linker option in the module. 198const char* lto_module_get_linkeropt(lto_module_t mod, unsigned int index) { 199 return mod->getLinkerOpt(index); 200} 201 202/// Set a diagnostic handler. 203void lto_codegen_set_diagnostic_handler(lto_code_gen_t cg, 204 lto_diagnostic_handler_t diag_handler, 205 void *ctxt) { 206 cg->setDiagnosticHandler(diag_handler, ctxt); 207} 208 209/// lto_codegen_create - Instantiates a code generator. Returns NULL if there 210/// is an error. 211lto_code_gen_t lto_codegen_create(void) { 212 lto_initialize(); 213 214 TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); 215 216 LTOCodeGenerator *CodeGen = new LTOCodeGenerator(); 217 if (CodeGen) 218 CodeGen->setTargetOptions(Options); 219 return CodeGen; 220} 221 222/// lto_codegen_dispose - Frees all memory for a code generator. Upon return the 223/// lto_code_gen_t is no longer valid. 224void lto_codegen_dispose(lto_code_gen_t cg) { 225 delete cg; 226} 227 228/// lto_codegen_add_module - Add an object module to the set of modules for 229/// which code will be generated. Returns true on error (check 230/// lto_get_error_message() for details). 231bool lto_codegen_add_module(lto_code_gen_t cg, lto_module_t mod) { 232 return !cg->addModule(mod, sLastErrorString); 233} 234 235/// lto_codegen_set_debug_model - Sets what if any format of debug info should 236/// be generated. Returns true on error (check lto_get_error_message() for 237/// details). 238bool lto_codegen_set_debug_model(lto_code_gen_t cg, lto_debug_model debug) { 239 cg->setDebugInfo(debug); 240 return false; 241} 242 243/// lto_codegen_set_pic_model - Sets what code model to generated. Returns true 244/// on error (check lto_get_error_message() for details). 245bool lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model model) { 246 cg->setCodePICModel(model); 247 return false; 248} 249 250/// lto_codegen_set_cpu - Sets the cpu to generate code for. 251void lto_codegen_set_cpu(lto_code_gen_t cg, const char *cpu) { 252 return cg->setCpu(cpu); 253} 254 255/// lto_codegen_set_assembler_path - Sets the path to the assembler tool. 256void lto_codegen_set_assembler_path(lto_code_gen_t cg, const char *path) { 257 // In here only for backwards compatibility. We use MC now. 258} 259 260/// lto_codegen_set_assembler_args - Sets extra arguments that libLTO should 261/// pass to the assembler. 262void lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args, 263 int nargs) { 264 // In here only for backwards compatibility. We use MC now. 265} 266 267/// lto_codegen_add_must_preserve_symbol - Adds to a list of all global symbols 268/// that must exist in the final generated code. If a function is not listed 269/// there, it might be inlined into every usage and optimized away. 270void lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg, 271 const char *symbol) { 272 cg->addMustPreserveSymbol(symbol); 273} 274 275/// lto_codegen_write_merged_modules - Writes a new file at the specified path 276/// that contains the merged contents of all modules added so far. Returns true 277/// on error (check lto_get_error_message() for details). 278bool lto_codegen_write_merged_modules(lto_code_gen_t cg, const char *path) { 279 if (!parsedOptions) { 280 cg->parseCodeGenDebugOptions(); 281 parsedOptions = true; 282 } 283 return !cg->writeMergedModules(path, sLastErrorString); 284} 285 286/// lto_codegen_compile - Generates code for all added modules into one native 287/// object file. On success returns a pointer to a generated mach-o/ELF buffer 288/// and length set to the buffer size. The buffer is owned by the lto_code_gen_t 289/// object and will be freed when lto_codegen_dispose() is called, or 290/// lto_codegen_compile() is called again. On failure, returns NULL (check 291/// lto_get_error_message() for details). 292const void *lto_codegen_compile(lto_code_gen_t cg, size_t *length) { 293 if (!parsedOptions) { 294 cg->parseCodeGenDebugOptions(); 295 parsedOptions = true; 296 } 297 return cg->compile(length, DisableOpt, DisableInline, DisableGVNLoadPRE, 298 sLastErrorString); 299} 300 301/// lto_codegen_compile_to_file - Generates code for all added modules into one 302/// native object file. The name of the file is written to name. Returns true on 303/// error. 304bool lto_codegen_compile_to_file(lto_code_gen_t cg, const char **name) { 305 if (!parsedOptions) { 306 cg->parseCodeGenDebugOptions(); 307 parsedOptions = true; 308 } 309 return !cg->compile_to_file(name, DisableOpt, DisableInline, DisableGVNLoadPRE, 310 sLastErrorString); 311} 312 313/// lto_codegen_debug_options - Used to pass extra options to the code 314/// generator. 315void lto_codegen_debug_options(lto_code_gen_t cg, const char *opt) { 316 cg->setCodeGenDebugOptions(opt); 317} 318