llvm.org GIT mirror llvm / 4f89709
libLTO: Allow linker to choose context of modules and codegen Add API for specifying which `LLVMContext` each `lto_module_t` and `lto_code_gen_t` is in. In particular, this enables the following flow: for (auto &File : Files) { lto_module_t M = lto_module_create_in_local_context(File...); querySymbols(M); lto_module_dispose(M); } lto_code_gen_t CG = lto_codegen_create_in_local_context(); for (auto &File : FilesToLink) { lto_module_t M = lto_module_create_in_codegen_context(File..., CG); lto_codegen_add_module(CG, M); lto_module_dispose(M); } lto_codegen_compile(CG); lto_codegen_write_merged_modules(CG, ...); lto_codegen_dispose(CG); This flow has a few benefits. - Only one module (two if you count the combined module in the code generator) is in memory at a time. - Metadata (and constants) from files that are parsed to query symbols but not linked into the code generator don't pollute the global context. - The first for loop can be parallelized, since each module is in its own context. - When the code generator is disposed, the memory from LTO gets freed. rdar://problem/18767512 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221733 91177308-0d34-0410-b5e6-96231b3b80d8 Duncan P. N. Exon Smith 4 years ago
2 changed file(s) with 67 addition(s) and 1 deletion(s). Raw diff Collapse all Expand all
3939 * @{
4040 */
4141
42 #define LTO_API_VERSION 10
42 #define LTO_API_VERSION 11
4343
4444 /**
4545 * \since prior to LTO_API_VERSION=3
177177 const char *path);
178178
179179 /**
180 * \brief Loads an object file in its own context.
181 *
182 * Loads an object file in its own LLVMContext. This function call is
183 * thread-safe. However, modules created this way should not be merged into an
184 * lto_code_gen_t using \a lto_codegen_add_module().
185 *
186 * Returns NULL on error (check lto_get_error_message() for details).
187 *
188 * \since LTO_API_VERSION=11
189 */
190 extern lto_module_t
191 lto_module_create_in_local_context(const void *mem, size_t length,
192 const char *path);
193
194 /**
195 * \brief Loads an object file in the codegen context.
196 *
197 * Loads an object file into the same context as \c cg. The module is safe to
198 * add using \a lto_codegen_add_module().
199 *
200 * Returns NULL on error (check lto_get_error_message() for details).
201 *
202 * \since LTO_API_VERSION=11
203 */
204 extern lto_module_t
205 lto_module_create_in_codegen_context(const void *mem, size_t length,
206 const char *path, lto_code_gen_t cg);
207
208 /**
180209 * Loads an object file from disk. The seek point of fd is not preserved.
181210 * Returns NULL on error (check lto_get_error_message() for details).
182211 *
323352 * Instantiates a code generator.
324353 * Returns NULL on error (check lto_get_error_message() for details).
325354 *
355 * All modules added using \a lto_codegen_add_module() must have been created
356 * in the same context as the codegen.
357 *
326358 * \since prior to LTO_API_VERSION=3
327359 */
328360 extern lto_code_gen_t
329361 lto_codegen_create(void);
330362
331363 /**
364 * \brief Instantiate a code generator in its own context.
365 *
366 * Instantiates a code generator in its own context. Modules added via \a
367 * lto_codegen_add_module() must have all been created in the same context,
368 * using \a lto_module_create_in_codegen_context().
369 *
370 * \since LTO_API_VERSION=11
371 */
372 extern lto_code_gen_t
373 lto_codegen_create_in_local_context(void);
374
375 /**
332376 * Frees all code generator and all memory it internally allocated.
333377 * Upon return the lto_code_gen_t is no longer valid.
334378 *
340384 /**
341385 * Add an object module to the set of modules for which code will be generated.
342386 * Returns true on error (check lto_get_error_message() for details).
387 *
388 * \c cg and \c mod must both be in the same context. See \a
389 * lto_codegen_create_in_local_context() and \a
390 * lto_module_create_in_codegen_context().
343391 *
344392 * \since prior to LTO_API_VERSION=3
345393 */
149149 LTOModule::createFromBuffer(mem, length, Options, sLastErrorString, path));
150150 }
151151
152 lto_module_t lto_module_create_in_local_context(const void *mem, size_t length,
153 const char *path) {
154 lto_initialize();
155 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
156 return wrap(LTOModule::createInLocalContext(mem, length, Options,
157 sLastErrorString, path));
158 }
159
160 lto_module_t lto_module_create_in_codegen_context(const void *mem,
161 size_t length,
162 const char *path,
163 lto_code_gen_t cg) {
164 lto_initialize();
165 llvm::TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
166 return wrap(LTOModule::createInContext(mem, length, Options, sLastErrorString,
167 path, &unwrap(cg)->getContext()));
168 }
169
152170 void lto_module_dispose(lto_module_t mod) { delete unwrap(mod); }
153171
154172 const char* lto_module_get_target_triple(lto_module_t mod) {