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/DiagnosticInfo.h"
19 #include "llvm/IR/DiagnosticPrinter.h"
20 #include "llvm/IR/LLVMContext.h"
21 #include "llvm/LTO/LTOCodeGenerator.h"
22 #include "llvm/LTO/LTOModule.h"
23 #include "llvm/Support/MemoryBuffer.h"
24 #include "llvm/Support/Signals.h"
25 #include "llvm/Support/TargetSelect.h"
26
27 // extra command-line flags needed for LTOCodeGenerator
28 static cl::opt<char>
29 OptLevel("O",
30 cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
31 "(default = '-O2')"),
32 cl::Prefix,
33 cl::ZeroOrMore,
34 cl::init('2'));
35
36 static cl::opt<bool>
37 DisableInline("disable-inlining", cl::init(false),
38 cl::desc("Do not run the inliner pass"));
39
40 static cl::opt<bool>
41 DisableGVNLoadPRE("disable-gvn-loadpre", cl::init(false),
42 cl::desc("Do not run the GVN load PRE pass"));
43
44 static cl::opt<bool>
45 DisableLTOVectorization("disable-lto-vectorization", cl::init(false),
46 cl::desc("Do not run loop or slp vectorization during LTO"));
47
48 #ifdef NDEBUG
49 static bool VerifyByDefault = false;
50 #else
51 static bool VerifyByDefault = true;
52 #endif
53
54 static cl::opt<bool> DisableVerify(
55 "disable-llvm-verifier", cl::init(!VerifyByDefault),
56 cl::desc("Don't run the LLVM verifier during the optimization pipeline"));
57
58 // Holds most recent error string.
59 // *** Not thread safe ***
60 static std::string sLastErrorString;
61
62 // Holds the initialization state of the LTO module.
63 // *** Not thread safe ***
64 static bool initialized = false;
65
66 // Holds the command-line option parsing state of the LTO module.
67 static bool parsedOptions = false;
68
69 static LLVMContext *LTOContext = nullptr;
70
diagnosticHandler(const DiagnosticInfo & DI,void * Context)71 static void diagnosticHandler(const DiagnosticInfo &DI, void *Context) {
72 if (DI.getSeverity() != DS_Error) {
73 DiagnosticPrinterRawOStream DP(errs());
74 DI.print(DP);
75 errs() << '\n';
76 return;
77 }
78 sLastErrorString = "";
79 {
80 raw_string_ostream Stream(sLastErrorString);
81 DiagnosticPrinterRawOStream DP(Stream);
82 DI.print(DP);
83 }
84 sLastErrorString += '\n';
85 }
86
87 // Initialize the configured targets if they have not been initialized.
lto_initialize()88 static void lto_initialize() {
89 if (!initialized) {
90 #ifdef LLVM_ON_WIN32
91 // Dialog box on crash disabling doesn't work across DLL boundaries, so do
92 // it here.
93 llvm::sys::DisableSystemDialogsOnCrash();
94 #endif
95
96 InitializeAllTargetInfos();
97 InitializeAllTargets();
98 InitializeAllTargetMCs();
99 InitializeAllAsmParsers();
100 InitializeAllAsmPrinters();
101 InitializeAllDisassemblers();
102
103 LTOContext = &getGlobalContext();
104 LTOContext->setDiagnosticHandler(diagnosticHandler, nullptr, true);
105 initialized = true;
106 }
107 }
108
109 namespace {
110
handleLibLTODiagnostic(lto_codegen_diagnostic_severity_t Severity,const char * Msg,void *)111 static void handleLibLTODiagnostic(lto_codegen_diagnostic_severity_t Severity,
112 const char *Msg, void *) {
113 sLastErrorString = Msg;
114 sLastErrorString += "\n";
115 }
116
117 // This derived class owns the native object file. This helps implement the
118 // libLTO API semantics, which require that the code generator owns the object
119 // file.
120 struct LibLTOCodeGenerator : LTOCodeGenerator {
LibLTOCodeGenerator__anon34e247e50111::LibLTOCodeGenerator121 LibLTOCodeGenerator() : LTOCodeGenerator(*LTOContext) {
122 setDiagnosticHandler(handleLibLTODiagnostic, nullptr); }
LibLTOCodeGenerator__anon34e247e50111::LibLTOCodeGenerator123 LibLTOCodeGenerator(std::unique_ptr<LLVMContext> Context)
124 : LTOCodeGenerator(*Context), OwnedContext(std::move(Context)) {
125 setDiagnosticHandler(handleLibLTODiagnostic, nullptr); }
126
127 // Reset the module first in case MergedModule is created in OwnedContext.
128 // Module must be destructed before its context gets destructed.
~LibLTOCodeGenerator__anon34e247e50111::LibLTOCodeGenerator129 ~LibLTOCodeGenerator() { resetMergedModule(); }
130
131 std::unique_ptr<MemoryBuffer> NativeObjectFile;
132 std::unique_ptr<LLVMContext> OwnedContext;
133 };
134
135 }
136
DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LibLTOCodeGenerator,lto_code_gen_t)137 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LibLTOCodeGenerator, lto_code_gen_t)
138 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LTOModule, lto_module_t)
139
140 // Convert the subtarget features into a string to pass to LTOCodeGenerator.
141 static void lto_add_attrs(lto_code_gen_t cg) {
142 LTOCodeGenerator *CG = unwrap(cg);
143 if (MAttrs.size()) {
144 std::string attrs;
145 for (unsigned i = 0; i < MAttrs.size(); ++i) {
146 if (i > 0)
147 attrs.append(",");
148 attrs.append(MAttrs[i]);
149 }
150
151 CG->setAttr(attrs.c_str());
152 }
153
154 if (OptLevel < '0' || OptLevel > '3')
155 report_fatal_error("Optimization level must be between 0 and 3");
156 CG->setOptLevel(OptLevel - '0');
157 }
158
lto_get_version()159 extern const char* lto_get_version() {
160 return LTOCodeGenerator::getVersionString();
161 }
162
lto_get_error_message()163 const char* lto_get_error_message() {
164 return sLastErrorString.c_str();
165 }
166
lto_module_is_object_file(const char * path)167 bool lto_module_is_object_file(const char* path) {
168 return LTOModule::isBitcodeFile(path);
169 }
170
lto_module_is_object_file_for_target(const char * path,const char * target_triplet_prefix)171 bool lto_module_is_object_file_for_target(const char* path,
172 const char* target_triplet_prefix) {
173 ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer = MemoryBuffer::getFile(path);
174 if (!Buffer)
175 return false;
176 return LTOModule::isBitcodeForTarget(Buffer->get(), target_triplet_prefix);
177 }
178
lto_module_is_object_file_in_memory(const void * mem,size_t length)179 bool lto_module_is_object_file_in_memory(const void* mem, size_t length) {
180 return LTOModule::isBitcodeFile(mem, length);
181 }
182
183 bool
lto_module_is_object_file_in_memory_for_target(const void * mem,size_t length,const char * target_triplet_prefix)184 lto_module_is_object_file_in_memory_for_target(const void* mem,
185 size_t length,
186 const char* target_triplet_prefix) {
187 std::unique_ptr<MemoryBuffer> buffer(LTOModule::makeBuffer(mem, length));
188 if (!buffer)
189 return false;
190 return LTOModule::isBitcodeForTarget(buffer.get(), target_triplet_prefix);
191 }
192
lto_module_create(const char * path)193 lto_module_t lto_module_create(const char* path) {
194 lto_initialize();
195 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
196 ErrorOr<std::unique_ptr<LTOModule>> M =
197 LTOModule::createFromFile(*LTOContext, path, Options);
198 if (!M)
199 return nullptr;
200 return wrap(M->release());
201 }
202
lto_module_create_from_fd(int fd,const char * path,size_t size)203 lto_module_t lto_module_create_from_fd(int fd, const char *path, size_t size) {
204 lto_initialize();
205 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
206 ErrorOr<std::unique_ptr<LTOModule>> M =
207 LTOModule::createFromOpenFile(*LTOContext, fd, path, size, Options);
208 if (!M)
209 return nullptr;
210 return wrap(M->release());
211 }
212
lto_module_create_from_fd_at_offset(int fd,const char * path,size_t file_size,size_t map_size,off_t offset)213 lto_module_t lto_module_create_from_fd_at_offset(int fd, const char *path,
214 size_t file_size,
215 size_t map_size,
216 off_t offset) {
217 lto_initialize();
218 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
219 ErrorOr<std::unique_ptr<LTOModule>> M = LTOModule::createFromOpenFileSlice(
220 *LTOContext, fd, path, map_size, offset, Options);
221 if (!M)
222 return nullptr;
223 return wrap(M->release());
224 }
225
lto_module_create_from_memory(const void * mem,size_t length)226 lto_module_t lto_module_create_from_memory(const void* mem, size_t length) {
227 lto_initialize();
228 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
229 ErrorOr<std::unique_ptr<LTOModule>> M =
230 LTOModule::createFromBuffer(*LTOContext, mem, length, Options);
231 if (!M)
232 return nullptr;
233 return wrap(M->release());
234 }
235
lto_module_create_from_memory_with_path(const void * mem,size_t length,const char * path)236 lto_module_t lto_module_create_from_memory_with_path(const void* mem,
237 size_t length,
238 const char *path) {
239 lto_initialize();
240 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
241 ErrorOr<std::unique_ptr<LTOModule>> M =
242 LTOModule::createFromBuffer(*LTOContext, mem, length, Options, path);
243 if (!M)
244 return nullptr;
245 return wrap(M->release());
246 }
247
lto_module_create_in_local_context(const void * mem,size_t length,const char * path)248 lto_module_t lto_module_create_in_local_context(const void *mem, size_t length,
249 const char *path) {
250 lto_initialize();
251 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
252 ErrorOr<std::unique_ptr<LTOModule>> M =
253 LTOModule::createInLocalContext(mem, length, Options, path);
254 if (!M)
255 return nullptr;
256 return wrap(M->release());
257 }
258
lto_module_create_in_codegen_context(const void * mem,size_t length,const char * path,lto_code_gen_t cg)259 lto_module_t lto_module_create_in_codegen_context(const void *mem,
260 size_t length,
261 const char *path,
262 lto_code_gen_t cg) {
263 lto_initialize();
264 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
265 ErrorOr<std::unique_ptr<LTOModule>> M = LTOModule::createInContext(
266 mem, length, Options, path, &unwrap(cg)->getContext());
267 return wrap(M->release());
268 }
269
lto_module_dispose(lto_module_t mod)270 void lto_module_dispose(lto_module_t mod) { delete unwrap(mod); }
271
lto_module_get_target_triple(lto_module_t mod)272 const char* lto_module_get_target_triple(lto_module_t mod) {
273 return unwrap(mod)->getTargetTriple().c_str();
274 }
275
lto_module_set_target_triple(lto_module_t mod,const char * triple)276 void lto_module_set_target_triple(lto_module_t mod, const char *triple) {
277 return unwrap(mod)->setTargetTriple(triple);
278 }
279
lto_module_get_num_symbols(lto_module_t mod)280 unsigned int lto_module_get_num_symbols(lto_module_t mod) {
281 return unwrap(mod)->getSymbolCount();
282 }
283
lto_module_get_symbol_name(lto_module_t mod,unsigned int index)284 const char* lto_module_get_symbol_name(lto_module_t mod, unsigned int index) {
285 return unwrap(mod)->getSymbolName(index);
286 }
287
lto_module_get_symbol_attribute(lto_module_t mod,unsigned int index)288 lto_symbol_attributes lto_module_get_symbol_attribute(lto_module_t mod,
289 unsigned int index) {
290 return unwrap(mod)->getSymbolAttributes(index);
291 }
292
lto_module_get_linkeropts(lto_module_t mod)293 const char* lto_module_get_linkeropts(lto_module_t mod) {
294 return unwrap(mod)->getLinkerOpts();
295 }
296
lto_codegen_set_diagnostic_handler(lto_code_gen_t cg,lto_diagnostic_handler_t diag_handler,void * ctxt)297 void lto_codegen_set_diagnostic_handler(lto_code_gen_t cg,
298 lto_diagnostic_handler_t diag_handler,
299 void *ctxt) {
300 unwrap(cg)->setDiagnosticHandler(diag_handler, ctxt);
301 }
302
createCodeGen(bool InLocalContext)303 static lto_code_gen_t createCodeGen(bool InLocalContext) {
304 lto_initialize();
305
306 TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
307
308 LibLTOCodeGenerator *CodeGen =
309 InLocalContext ? new LibLTOCodeGenerator(make_unique<LLVMContext>())
310 : new LibLTOCodeGenerator();
311 CodeGen->setTargetOptions(Options);
312 return wrap(CodeGen);
313 }
314
lto_codegen_create(void)315 lto_code_gen_t lto_codegen_create(void) {
316 return createCodeGen(/* InLocalContext */ false);
317 }
318
lto_codegen_create_in_local_context(void)319 lto_code_gen_t lto_codegen_create_in_local_context(void) {
320 return createCodeGen(/* InLocalContext */ true);
321 }
322
lto_codegen_dispose(lto_code_gen_t cg)323 void lto_codegen_dispose(lto_code_gen_t cg) { delete unwrap(cg); }
324
lto_codegen_add_module(lto_code_gen_t cg,lto_module_t mod)325 bool lto_codegen_add_module(lto_code_gen_t cg, lto_module_t mod) {
326 return !unwrap(cg)->addModule(unwrap(mod));
327 }
328
lto_codegen_set_module(lto_code_gen_t cg,lto_module_t mod)329 void lto_codegen_set_module(lto_code_gen_t cg, lto_module_t mod) {
330 unwrap(cg)->setModule(std::unique_ptr<LTOModule>(unwrap(mod)));
331 }
332
lto_codegen_set_debug_model(lto_code_gen_t cg,lto_debug_model debug)333 bool lto_codegen_set_debug_model(lto_code_gen_t cg, lto_debug_model debug) {
334 unwrap(cg)->setDebugInfo(debug);
335 return false;
336 }
337
lto_codegen_set_pic_model(lto_code_gen_t cg,lto_codegen_model model)338 bool lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model model) {
339 switch (model) {
340 case LTO_CODEGEN_PIC_MODEL_STATIC:
341 unwrap(cg)->setCodePICModel(Reloc::Static);
342 return false;
343 case LTO_CODEGEN_PIC_MODEL_DYNAMIC:
344 unwrap(cg)->setCodePICModel(Reloc::PIC_);
345 return false;
346 case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC:
347 unwrap(cg)->setCodePICModel(Reloc::DynamicNoPIC);
348 return false;
349 case LTO_CODEGEN_PIC_MODEL_DEFAULT:
350 unwrap(cg)->setCodePICModel(Reloc::Default);
351 return false;
352 }
353 sLastErrorString = "Unknown PIC model";
354 return true;
355 }
356
lto_codegen_set_cpu(lto_code_gen_t cg,const char * cpu)357 void lto_codegen_set_cpu(lto_code_gen_t cg, const char *cpu) {
358 return unwrap(cg)->setCpu(cpu);
359 }
360
lto_codegen_set_assembler_path(lto_code_gen_t cg,const char * path)361 void lto_codegen_set_assembler_path(lto_code_gen_t cg, const char *path) {
362 // In here only for backwards compatibility. We use MC now.
363 }
364
lto_codegen_set_assembler_args(lto_code_gen_t cg,const char ** args,int nargs)365 void lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args,
366 int nargs) {
367 // In here only for backwards compatibility. We use MC now.
368 }
369
lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg,const char * symbol)370 void lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg,
371 const char *symbol) {
372 unwrap(cg)->addMustPreserveSymbol(symbol);
373 }
374
maybeParseOptions(lto_code_gen_t cg)375 static void maybeParseOptions(lto_code_gen_t cg) {
376 if (!parsedOptions) {
377 unwrap(cg)->parseCodeGenDebugOptions();
378 lto_add_attrs(cg);
379 parsedOptions = true;
380 }
381 }
382
lto_codegen_write_merged_modules(lto_code_gen_t cg,const char * path)383 bool lto_codegen_write_merged_modules(lto_code_gen_t cg, const char *path) {
384 maybeParseOptions(cg);
385 return !unwrap(cg)->writeMergedModules(path);
386 }
387
lto_codegen_compile(lto_code_gen_t cg,size_t * length)388 const void *lto_codegen_compile(lto_code_gen_t cg, size_t *length) {
389 maybeParseOptions(cg);
390 LibLTOCodeGenerator *CG = unwrap(cg);
391 CG->NativeObjectFile =
392 CG->compile(DisableVerify, DisableInline, DisableGVNLoadPRE,
393 DisableLTOVectorization);
394 if (!CG->NativeObjectFile)
395 return nullptr;
396 *length = CG->NativeObjectFile->getBufferSize();
397 return CG->NativeObjectFile->getBufferStart();
398 }
399
lto_codegen_optimize(lto_code_gen_t cg)400 bool lto_codegen_optimize(lto_code_gen_t cg) {
401 maybeParseOptions(cg);
402 return !unwrap(cg)->optimize(DisableVerify, DisableInline, DisableGVNLoadPRE,
403 DisableLTOVectorization);
404 }
405
lto_codegen_compile_optimized(lto_code_gen_t cg,size_t * length)406 const void *lto_codegen_compile_optimized(lto_code_gen_t cg, size_t *length) {
407 maybeParseOptions(cg);
408 LibLTOCodeGenerator *CG = unwrap(cg);
409 CG->NativeObjectFile = CG->compileOptimized();
410 if (!CG->NativeObjectFile)
411 return nullptr;
412 *length = CG->NativeObjectFile->getBufferSize();
413 return CG->NativeObjectFile->getBufferStart();
414 }
415
lto_codegen_compile_to_file(lto_code_gen_t cg,const char ** name)416 bool lto_codegen_compile_to_file(lto_code_gen_t cg, const char **name) {
417 maybeParseOptions(cg);
418 return !unwrap(cg)->compile_to_file(
419 name, DisableVerify, DisableInline, DisableGVNLoadPRE,
420 DisableLTOVectorization);
421 }
422
lto_codegen_debug_options(lto_code_gen_t cg,const char * opt)423 void lto_codegen_debug_options(lto_code_gen_t cg, const char *opt) {
424 unwrap(cg)->setCodeGenDebugOptions(opt);
425 }
426
lto_api_version()427 unsigned int lto_api_version() { return LTO_API_VERSION; }
428
lto_codegen_set_should_internalize(lto_code_gen_t cg,bool ShouldInternalize)429 void lto_codegen_set_should_internalize(lto_code_gen_t cg,
430 bool ShouldInternalize) {
431 unwrap(cg)->setShouldInternalize(ShouldInternalize);
432 }
433
lto_codegen_set_should_embed_uselists(lto_code_gen_t cg,lto_bool_t ShouldEmbedUselists)434 void lto_codegen_set_should_embed_uselists(lto_code_gen_t cg,
435 lto_bool_t ShouldEmbedUselists) {
436 unwrap(cg)->setShouldEmbedUselists(ShouldEmbedUselists);
437 }
438