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/ADT/STLExtras.h"
17 #include "llvm/CodeGen/CommandFlags.h"
18 #include "llvm/IR/LLVMContext.h"
19 #include "llvm/LTO/LTOCodeGenerator.h"
20 #include "llvm/LTO/LTOModule.h"
21 #include "llvm/Support/MemoryBuffer.h"
22 #include "llvm/Support/Signals.h"
23 #include "llvm/Support/TargetSelect.h"
24 
25 // extra command-line flags needed for LTOCodeGenerator
26 static cl::opt<char>
27 OptLevel("O",
28          cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
29                   "(default = '-O2')"),
30          cl::Prefix,
31          cl::ZeroOrMore,
32          cl::init('2'));
33 
34 static cl::opt<bool>
35 DisableInline("disable-inlining", cl::init(false),
36   cl::desc("Do not run the inliner pass"));
37 
38 static cl::opt<bool>
39 DisableGVNLoadPRE("disable-gvn-loadpre", cl::init(false),
40   cl::desc("Do not run the GVN load PRE pass"));
41 
42 static cl::opt<bool>
43 DisableLTOVectorization("disable-lto-vectorization", cl::init(false),
44   cl::desc("Do not run loop or slp vectorization during LTO"));
45 
46 // Holds most recent error string.
47 // *** Not thread safe ***
48 static std::string sLastErrorString;
49 
50 // Holds the initialization state of the LTO module.
51 // *** Not thread safe ***
52 static bool initialized = false;
53 
54 // Holds the command-line option parsing state of the LTO module.
55 static bool parsedOptions = false;
56 
57 // Initialize the configured targets if they have not been initialized.
lto_initialize()58 static void lto_initialize() {
59   if (!initialized) {
60 #ifdef LLVM_ON_WIN32
61     // Dialog box on crash disabling doesn't work across DLL boundaries, so do
62     // it here.
63     llvm::sys::DisableSystemDialogsOnCrash();
64 #endif
65 
66     InitializeAllTargetInfos();
67     InitializeAllTargets();
68     InitializeAllTargetMCs();
69     InitializeAllAsmParsers();
70     InitializeAllAsmPrinters();
71     InitializeAllDisassemblers();
72     initialized = true;
73   }
74 }
75 
DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LTOCodeGenerator,lto_code_gen_t)76 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LTOCodeGenerator, lto_code_gen_t)
77 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LTOModule, lto_module_t)
78 
79 // Convert the subtarget features into a string to pass to LTOCodeGenerator.
80 static void lto_add_attrs(lto_code_gen_t cg) {
81   LTOCodeGenerator *CG = unwrap(cg);
82   if (MAttrs.size()) {
83     std::string attrs;
84     for (unsigned i = 0; i < MAttrs.size(); ++i) {
85       if (i > 0)
86         attrs.append(",");
87       attrs.append(MAttrs[i]);
88     }
89 
90     CG->setAttr(attrs.c_str());
91   }
92 
93   if (OptLevel < '0' || OptLevel > '3')
94     report_fatal_error("Optimization level must be between 0 and 3");
95   CG->setOptLevel(OptLevel - '0');
96 }
97 
lto_get_version()98 extern const char* lto_get_version() {
99   return LTOCodeGenerator::getVersionString();
100 }
101 
lto_get_error_message()102 const char* lto_get_error_message() {
103   return sLastErrorString.c_str();
104 }
105 
lto_module_is_object_file(const char * path)106 bool lto_module_is_object_file(const char* path) {
107   return LTOModule::isBitcodeFile(path);
108 }
109 
lto_module_is_object_file_for_target(const char * path,const char * target_triplet_prefix)110 bool lto_module_is_object_file_for_target(const char* path,
111                                           const char* target_triplet_prefix) {
112   ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer = MemoryBuffer::getFile(path);
113   if (!Buffer)
114     return false;
115   return LTOModule::isBitcodeForTarget(Buffer->get(), target_triplet_prefix);
116 }
117 
lto_module_is_object_file_in_memory(const void * mem,size_t length)118 bool lto_module_is_object_file_in_memory(const void* mem, size_t length) {
119   return LTOModule::isBitcodeFile(mem, length);
120 }
121 
122 bool
lto_module_is_object_file_in_memory_for_target(const void * mem,size_t length,const char * target_triplet_prefix)123 lto_module_is_object_file_in_memory_for_target(const void* mem,
124                                             size_t length,
125                                             const char* target_triplet_prefix) {
126   std::unique_ptr<MemoryBuffer> buffer(LTOModule::makeBuffer(mem, length));
127   if (!buffer)
128     return false;
129   return LTOModule::isBitcodeForTarget(buffer.get(), target_triplet_prefix);
130 }
131 
lto_module_create(const char * path)132 lto_module_t lto_module_create(const char* path) {
133   lto_initialize();
134   llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
135   return wrap(LTOModule::createFromFile(path, Options, sLastErrorString));
136 }
137 
lto_module_create_from_fd(int fd,const char * path,size_t size)138 lto_module_t lto_module_create_from_fd(int fd, const char *path, size_t size) {
139   lto_initialize();
140   llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
141   return wrap(
142       LTOModule::createFromOpenFile(fd, path, size, Options, sLastErrorString));
143 }
144 
lto_module_create_from_fd_at_offset(int fd,const char * path,size_t file_size,size_t map_size,off_t offset)145 lto_module_t lto_module_create_from_fd_at_offset(int fd, const char *path,
146                                                  size_t file_size,
147                                                  size_t map_size,
148                                                  off_t offset) {
149   lto_initialize();
150   llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
151   return wrap(LTOModule::createFromOpenFileSlice(fd, path, map_size, offset,
152                                                  Options, sLastErrorString));
153 }
154 
lto_module_create_from_memory(const void * mem,size_t length)155 lto_module_t lto_module_create_from_memory(const void* mem, size_t length) {
156   lto_initialize();
157   llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
158   return wrap(LTOModule::createFromBuffer(mem, length, Options, sLastErrorString));
159 }
160 
lto_module_create_from_memory_with_path(const void * mem,size_t length,const char * path)161 lto_module_t lto_module_create_from_memory_with_path(const void* mem,
162                                                      size_t length,
163                                                      const char *path) {
164   lto_initialize();
165   llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
166   return wrap(
167       LTOModule::createFromBuffer(mem, length, Options, sLastErrorString, path));
168 }
169 
lto_module_create_in_local_context(const void * mem,size_t length,const char * path)170 lto_module_t lto_module_create_in_local_context(const void *mem, size_t length,
171                                                 const char *path) {
172   lto_initialize();
173   llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
174   return wrap(LTOModule::createInLocalContext(mem, length, Options,
175                                               sLastErrorString, path));
176 }
177 
lto_module_create_in_codegen_context(const void * mem,size_t length,const char * path,lto_code_gen_t cg)178 lto_module_t lto_module_create_in_codegen_context(const void *mem,
179                                                   size_t length,
180                                                   const char *path,
181                                                   lto_code_gen_t cg) {
182   lto_initialize();
183   llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
184   return wrap(LTOModule::createInContext(mem, length, Options, sLastErrorString,
185                                          path, &unwrap(cg)->getContext()));
186 }
187 
lto_module_dispose(lto_module_t mod)188 void lto_module_dispose(lto_module_t mod) { delete unwrap(mod); }
189 
lto_module_get_target_triple(lto_module_t mod)190 const char* lto_module_get_target_triple(lto_module_t mod) {
191   return unwrap(mod)->getTargetTriple().c_str();
192 }
193 
lto_module_set_target_triple(lto_module_t mod,const char * triple)194 void lto_module_set_target_triple(lto_module_t mod, const char *triple) {
195   return unwrap(mod)->setTargetTriple(triple);
196 }
197 
lto_module_get_num_symbols(lto_module_t mod)198 unsigned int lto_module_get_num_symbols(lto_module_t mod) {
199   return unwrap(mod)->getSymbolCount();
200 }
201 
lto_module_get_symbol_name(lto_module_t mod,unsigned int index)202 const char* lto_module_get_symbol_name(lto_module_t mod, unsigned int index) {
203   return unwrap(mod)->getSymbolName(index);
204 }
205 
lto_module_get_symbol_attribute(lto_module_t mod,unsigned int index)206 lto_symbol_attributes lto_module_get_symbol_attribute(lto_module_t mod,
207                                                       unsigned int index) {
208   return unwrap(mod)->getSymbolAttributes(index);
209 }
210 
lto_module_get_num_deplibs(lto_module_t mod)211 unsigned int lto_module_get_num_deplibs(lto_module_t mod) {
212   return unwrap(mod)->getDependentLibraryCount();
213 }
214 
lto_module_get_deplib(lto_module_t mod,unsigned int index)215 const char* lto_module_get_deplib(lto_module_t mod, unsigned int index) {
216   return unwrap(mod)->getDependentLibrary(index);
217 }
218 
lto_module_get_num_linkeropts(lto_module_t mod)219 unsigned int lto_module_get_num_linkeropts(lto_module_t mod) {
220   return unwrap(mod)->getLinkerOptCount();
221 }
222 
lto_module_get_linkeropt(lto_module_t mod,unsigned int index)223 const char* lto_module_get_linkeropt(lto_module_t mod, unsigned int index) {
224   return unwrap(mod)->getLinkerOpt(index);
225 }
226 
lto_codegen_set_diagnostic_handler(lto_code_gen_t cg,lto_diagnostic_handler_t diag_handler,void * ctxt)227 void lto_codegen_set_diagnostic_handler(lto_code_gen_t cg,
228                                         lto_diagnostic_handler_t diag_handler,
229                                         void *ctxt) {
230   unwrap(cg)->setDiagnosticHandler(diag_handler, ctxt);
231 }
232 
createCodeGen(bool InLocalContext)233 static lto_code_gen_t createCodeGen(bool InLocalContext) {
234   lto_initialize();
235 
236   TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
237 
238   LTOCodeGenerator *CodeGen =
239       InLocalContext ? new LTOCodeGenerator(make_unique<LLVMContext>())
240                      : new LTOCodeGenerator();
241   if (CodeGen)
242     CodeGen->setTargetOptions(Options);
243   return wrap(CodeGen);
244 }
245 
lto_codegen_create(void)246 lto_code_gen_t lto_codegen_create(void) {
247   return createCodeGen(/* InLocalContext */ false);
248 }
249 
lto_codegen_create_in_local_context(void)250 lto_code_gen_t lto_codegen_create_in_local_context(void) {
251   return createCodeGen(/* InLocalContext */ true);
252 }
253 
lto_codegen_dispose(lto_code_gen_t cg)254 void lto_codegen_dispose(lto_code_gen_t cg) { delete unwrap(cg); }
255 
lto_codegen_add_module(lto_code_gen_t cg,lto_module_t mod)256 bool lto_codegen_add_module(lto_code_gen_t cg, lto_module_t mod) {
257   return !unwrap(cg)->addModule(unwrap(mod));
258 }
259 
lto_codegen_set_module(lto_code_gen_t cg,lto_module_t mod)260 void lto_codegen_set_module(lto_code_gen_t cg, lto_module_t mod) {
261   unwrap(cg)->setModule(unwrap(mod));
262 }
263 
lto_codegen_set_debug_model(lto_code_gen_t cg,lto_debug_model debug)264 bool lto_codegen_set_debug_model(lto_code_gen_t cg, lto_debug_model debug) {
265   unwrap(cg)->setDebugInfo(debug);
266   return false;
267 }
268 
lto_codegen_set_pic_model(lto_code_gen_t cg,lto_codegen_model model)269 bool lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model model) {
270   unwrap(cg)->setCodePICModel(model);
271   return false;
272 }
273 
lto_codegen_set_cpu(lto_code_gen_t cg,const char * cpu)274 void lto_codegen_set_cpu(lto_code_gen_t cg, const char *cpu) {
275   return unwrap(cg)->setCpu(cpu);
276 }
277 
lto_codegen_set_assembler_path(lto_code_gen_t cg,const char * path)278 void lto_codegen_set_assembler_path(lto_code_gen_t cg, const char *path) {
279   // In here only for backwards compatibility. We use MC now.
280 }
281 
lto_codegen_set_assembler_args(lto_code_gen_t cg,const char ** args,int nargs)282 void lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args,
283                                     int nargs) {
284   // In here only for backwards compatibility. We use MC now.
285 }
286 
lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg,const char * symbol)287 void lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg,
288                                           const char *symbol) {
289   unwrap(cg)->addMustPreserveSymbol(symbol);
290 }
291 
maybeParseOptions(lto_code_gen_t cg)292 static void maybeParseOptions(lto_code_gen_t cg) {
293   if (!parsedOptions) {
294     unwrap(cg)->parseCodeGenDebugOptions();
295     lto_add_attrs(cg);
296     parsedOptions = true;
297   }
298 }
299 
lto_codegen_write_merged_modules(lto_code_gen_t cg,const char * path)300 bool lto_codegen_write_merged_modules(lto_code_gen_t cg, const char *path) {
301   maybeParseOptions(cg);
302   return !unwrap(cg)->writeMergedModules(path, sLastErrorString);
303 }
304 
lto_codegen_compile(lto_code_gen_t cg,size_t * length)305 const void *lto_codegen_compile(lto_code_gen_t cg, size_t *length) {
306   maybeParseOptions(cg);
307   return unwrap(cg)->compile(length, DisableInline,
308                              DisableGVNLoadPRE, DisableLTOVectorization,
309                              sLastErrorString);
310 }
311 
lto_codegen_optimize(lto_code_gen_t cg)312 bool lto_codegen_optimize(lto_code_gen_t cg) {
313   maybeParseOptions(cg);
314   return !unwrap(cg)->optimize(DisableInline,
315                                DisableGVNLoadPRE, DisableLTOVectorization,
316                                sLastErrorString);
317 }
318 
lto_codegen_compile_optimized(lto_code_gen_t cg,size_t * length)319 const void *lto_codegen_compile_optimized(lto_code_gen_t cg, size_t *length) {
320   maybeParseOptions(cg);
321   return unwrap(cg)->compileOptimized(length, sLastErrorString);
322 }
323 
lto_codegen_compile_to_file(lto_code_gen_t cg,const char ** name)324 bool lto_codegen_compile_to_file(lto_code_gen_t cg, const char **name) {
325   maybeParseOptions(cg);
326   return !unwrap(cg)->compile_to_file(
327       name, DisableInline, DisableGVNLoadPRE,
328       DisableLTOVectorization, sLastErrorString);
329 }
330 
lto_codegen_debug_options(lto_code_gen_t cg,const char * opt)331 void lto_codegen_debug_options(lto_code_gen_t cg, const char *opt) {
332   unwrap(cg)->setCodeGenDebugOptions(opt);
333 }
334 
lto_api_version()335 unsigned int lto_api_version() { return LTO_API_VERSION; }
336