include/llvm-c/lto.h

   1 /*===-- llvm-c/lto.h - LTO Public C Interface ---------------------*- C -*-===*\
   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 header provides public interface to an abstract link time optimization*|
  11 |* library.  LLVM provides an implementation of this interface for use with   *|
  12 |* llvm bitcode files.                                                        *|
  13 |*                                                                            *|
  14 \*===----------------------------------------------------------------------===*/
  15
  16 #ifndef LLVM_C_LTO_H
  17 #define LLVM_C_LTO_H
  18
  19 #ifdef __cplusplus
  20 #include <cstddef>
  21 #else
  22 #include <stddef.h>
  23 #endif
  24 #include <sys/types.h>
  25
  26 #ifndef __cplusplus
  27 #if !defined(_MSC_VER)
  28 #include <stdbool.h>
  29 typedef bool lto_bool_t;
  30 #else
  31 /* MSVC in particular does not have anything like _Bool or bool in C, but we can
  32    at least make sure the type is the same size.  The implementation side will
  33    use C++ bool. */
  34 typedef unsigned char lto_bool_t;
  35 #endif
  36 #else
  37 typedef bool lto_bool_t;
  38 #endif
  39
  40 /**
  41  * @defgroup LLVMCLTO LTO
  42  * @ingroup LLVMC
  43  *
  44  * @{
  45  */
  46
  47 #define LTO_API_VERSION 21
  48
  49 /**
  50  * \since prior to LTO_API_VERSION=3
  51  */
  52 typedef enum {
  53     LTO_SYMBOL_ALIGNMENT_MASK              = 0x0000001F, /* log2 of alignment */
  54     LTO_SYMBOL_PERMISSIONS_MASK            = 0x000000E0,
  55     LTO_SYMBOL_PERMISSIONS_CODE            = 0x000000A0,
  56     LTO_SYMBOL_PERMISSIONS_DATA            = 0x000000C0,
  57     LTO_SYMBOL_PERMISSIONS_RODATA          = 0x00000080,
  58     LTO_SYMBOL_DEFINITION_MASK             = 0x00000700,
  59     LTO_SYMBOL_DEFINITION_REGULAR          = 0x00000100,
  60     LTO_SYMBOL_DEFINITION_TENTATIVE        = 0x00000200,
  61     LTO_SYMBOL_DEFINITION_WEAK             = 0x00000300,
  62     LTO_SYMBOL_DEFINITION_UNDEFINED        = 0x00000400,
  63     LTO_SYMBOL_DEFINITION_WEAKUNDEF        = 0x00000500,
  64     LTO_SYMBOL_SCOPE_MASK                  = 0x00003800,
  65     LTO_SYMBOL_SCOPE_INTERNAL              = 0x00000800,
  66     LTO_SYMBOL_SCOPE_HIDDEN                = 0x00001000,
  67     LTO_SYMBOL_SCOPE_PROTECTED             = 0x00002000,
  68     LTO_SYMBOL_SCOPE_DEFAULT               = 0x00001800,
  69     LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN = 0x00002800,
  70     LTO_SYMBOL_COMDAT                      = 0x00004000,
  71     LTO_SYMBOL_ALIAS                       = 0x00008000
  72 } lto_symbol_attributes;
  73
  74 /**
  75  * \since prior to LTO_API_VERSION=3
  76  */
  77 typedef enum {
  78     LTO_DEBUG_MODEL_NONE         = 0,
  79     LTO_DEBUG_MODEL_DWARF        = 1
  80 } lto_debug_model;
  81
  82 /**
  83  * \since prior to LTO_API_VERSION=3
  84  */
  85 typedef enum {
  86     LTO_CODEGEN_PIC_MODEL_STATIC         = 0,
  87     LTO_CODEGEN_PIC_MODEL_DYNAMIC        = 1,
  88     LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC = 2,
  89     LTO_CODEGEN_PIC_MODEL_DEFAULT        = 3
  90 } lto_codegen_model;
  91
  92 /** opaque reference to a loaded object module */
  93 typedef struct LLVMOpaqueLTOModule *lto_module_t;
  94
  95 /** opaque reference to a code generator */
  96 typedef struct LLVMOpaqueLTOCodeGenerator *lto_code_gen_t;
  97
  98 /** opaque reference to a thin code generator */
  99 typedef struct LLVMOpaqueThinLTOCodeGenerator *thinlto_code_gen_t;
 100
 101 #ifdef __cplusplus
 102 extern "C" {
 103 #endif
 104
 105 /**
 106  * Returns a printable string.
 107  *
 108  * \since prior to LTO_API_VERSION=3
 109  */
 110 extern const char*
 111 lto_get_version(void);
 112
 113 /**
 114  * Returns the last error string or NULL if last operation was successful.
 115  *
 116  * \since prior to LTO_API_VERSION=3
 117  */
 118 extern const char*
 119 lto_get_error_message(void);
 120
 121 /**
 122  * Checks if a file is a loadable object file.
 123  *
 124  * \since prior to LTO_API_VERSION=3
 125  */
 126 extern lto_bool_t
 127 lto_module_is_object_file(const char* path);
 128
 129 /**
 130  * Checks if a file is a loadable object compiled for requested target.
 131  *
 132  * \since prior to LTO_API_VERSION=3
 133  */
 134 extern lto_bool_t
 135 lto_module_is_object_file_for_target(const char* path,
 136                                      const char* target_triple_prefix);
 137
 138 /**
 139  * Return true if \p Buffer contains a bitcode file with ObjC code (category
 140  * or class) in it.
 141  *
 142  * \since LTO_API_VERSION=20
 143  */
 144 extern lto_bool_t
 145 lto_module_has_objc_category(const void *mem, size_t length);
 146
 147 /**
 148  * Checks if a buffer is a loadable object file.
 149  *
 150  * \since prior to LTO_API_VERSION=3
 151  */
 152 extern lto_bool_t lto_module_is_object_file_in_memory(const void *mem,
 153                                                       size_t length);
 154
 155 /**
 156  * Checks if a buffer is a loadable object compiled for requested target.
 157  *
 158  * \since prior to LTO_API_VERSION=3
 159  */
 160 extern lto_bool_t
 161 lto_module_is_object_file_in_memory_for_target(const void* mem, size_t length,
 162                                               const char* target_triple_prefix);
 163
 164 /**
 165  * Loads an object file from disk.
 166  * Returns NULL on error (check lto_get_error_message() for details).
 167  *
 168  * \since prior to LTO_API_VERSION=3
 169  */
 170 extern lto_module_t
 171 lto_module_create(const char* path);
 172
 173 /**
 174  * Loads an object file from memory.
 175  * Returns NULL on error (check lto_get_error_message() for details).
 176  *
 177  * \since prior to LTO_API_VERSION=3
 178  */
 179 extern lto_module_t
 180 lto_module_create_from_memory(const void* mem, size_t length);
 181
 182 /**
 183  * Loads an object file from memory with an extra path argument.
 184  * Returns NULL on error (check lto_get_error_message() for details).
 185  *
 186  * \since LTO_API_VERSION=9
 187  */
 188 extern lto_module_t
 189 lto_module_create_from_memory_with_path(const void* mem, size_t length,
 190                                         const char *path);
 191
 192 /**
 193  * \brief Loads an object file in its own context.
 194  *
 195  * Loads an object file in its own LLVMContext.  This function call is
 196  * thread-safe.  However, modules created this way should not be merged into an
 197  * lto_code_gen_t using \a lto_codegen_add_module().
 198  *
 199  * Returns NULL on error (check lto_get_error_message() for details).
 200  *
 201  * \since LTO_API_VERSION=11
 202  */
 203 extern lto_module_t
 204 lto_module_create_in_local_context(const void *mem, size_t length,
 205                                    const char *path);
 206
 207 /**
 208  * \brief Loads an object file in the codegen context.
 209  *
 210  * Loads an object file into the same context as \c cg.  The module is safe to
 211  * add using \a lto_codegen_add_module().
 212  *
 213  * Returns NULL on error (check lto_get_error_message() for details).
 214  *
 215  * \since LTO_API_VERSION=11
 216  */
 217 extern lto_module_t
 218 lto_module_create_in_codegen_context(const void *mem, size_t length,
 219                                      const char *path, lto_code_gen_t cg);
 220
 221 /**
 222  * Loads an object file from disk. The seek point of fd is not preserved.
 223  * Returns NULL on error (check lto_get_error_message() for details).
 224  *
 225  * \since LTO_API_VERSION=5
 226  */
 227 extern lto_module_t
 228 lto_module_create_from_fd(int fd, const char *path, size_t file_size);
 229
 230 /**
 231  * Loads an object file from disk. The seek point of fd is not preserved.
 232  * Returns NULL on error (check lto_get_error_message() for details).
 233  *
 234  * \since LTO_API_VERSION=5
 235  */
 236 extern lto_module_t
 237 lto_module_create_from_fd_at_offset(int fd, const char *path, size_t file_size,
 238                                     size_t map_size, off_t offset);
 239
 240 /**
 241  * Frees all memory internally allocated by the module.
 242  * Upon return the lto_module_t is no longer valid.
 243  *
 244  * \since prior to LTO_API_VERSION=3
 245  */
 246 extern void
 247 lto_module_dispose(lto_module_t mod);
 248
 249 /**
 250  * Returns triple string which the object module was compiled under.
 251  *
 252  * \since prior to LTO_API_VERSION=3
 253  */
 254 extern const char*
 255 lto_module_get_target_triple(lto_module_t mod);
 256
 257 /**
 258  * Sets triple string with which the object will be codegened.
 259  *
 260  * \since LTO_API_VERSION=4
 261  */
 262 extern void
 263 lto_module_set_target_triple(lto_module_t mod, const char *triple);
 264
 265 /**
 266  * Returns the number of symbols in the object module.
 267  *
 268  * \since prior to LTO_API_VERSION=3
 269  */
 270 extern unsigned int
 271 lto_module_get_num_symbols(lto_module_t mod);
 272
 273 /**
 274  * Returns the name of the ith symbol in the object module.
 275  *
 276  * \since prior to LTO_API_VERSION=3
 277  */
 278 extern const char*
 279 lto_module_get_symbol_name(lto_module_t mod, unsigned int index);
 280
 281 /**
 282  * Returns the attributes of the ith symbol in the object module.
 283  *
 284  * \since prior to LTO_API_VERSION=3
 285  */
 286 extern lto_symbol_attributes
 287 lto_module_get_symbol_attribute(lto_module_t mod, unsigned int index);
 288
 289 /**
 290  * Returns the module's linker options.
 291  *
 292  * The linker options may consist of multiple flags. It is the linker's
 293  * responsibility to split the flags using a platform-specific mechanism.
 294  *
 295  * \since LTO_API_VERSION=16
 296  */
 297 extern const char*
 298 lto_module_get_linkeropts(lto_module_t mod);
 299
 300 /**
 301  * Diagnostic severity.
 302  *
 303  * \since LTO_API_VERSION=7
 304  */
 305 typedef enum {
 306   LTO_DS_ERROR = 0,
 307   LTO_DS_WARNING = 1,
 308   LTO_DS_REMARK = 3, // Added in LTO_API_VERSION=10.
 309   LTO_DS_NOTE = 2
 310 } lto_codegen_diagnostic_severity_t;
 311
 312 /**
 313  * Diagnostic handler type.
 314  * \p severity defines the severity.
 315  * \p diag is the actual diagnostic.
 316  * The diagnostic is not prefixed by any of severity keyword, e.g., 'error: '.
 317  * \p ctxt is used to pass the context set with the diagnostic handler.
 318  *
 319  * \since LTO_API_VERSION=7
 320  */
 321 typedef void (*lto_diagnostic_handler_t)(
 322     lto_codegen_diagnostic_severity_t severity, const char *diag, void *ctxt);
 323
 324 /**
 325  * Set a diagnostic handler and the related context (void *).
 326  * This is more general than lto_get_error_message, as the diagnostic handler
 327  * can be called at anytime within lto.
 328  *
 329  * \since LTO_API_VERSION=7
 330  */
 331 extern void lto_codegen_set_diagnostic_handler(lto_code_gen_t,
 332                                                lto_diagnostic_handler_t,
 333                                                void *);
 334
 335 /**
 336  * Instantiates a code generator.
 337  * Returns NULL on error (check lto_get_error_message() for details).
 338  *
 339  * All modules added using \a lto_codegen_add_module() must have been created
 340  * in the same context as the codegen.
 341  *
 342  * \since prior to LTO_API_VERSION=3
 343  */
 344 extern lto_code_gen_t
 345 lto_codegen_create(void);
 346
 347 /**
 348  * \brief Instantiate a code generator in its own context.
 349  *
 350  * Instantiates a code generator in its own context.  Modules added via \a
 351  * lto_codegen_add_module() must have all been created in the same context,
 352  * using \a lto_module_create_in_codegen_context().
 353  *
 354  * \since LTO_API_VERSION=11
 355  */
 356 extern lto_code_gen_t
 357 lto_codegen_create_in_local_context(void);
 358
 359 /**
 360  * Frees all code generator and all memory it internally allocated.
 361  * Upon return the lto_code_gen_t is no longer valid.
 362  *
 363  * \since prior to LTO_API_VERSION=3
 364  */
 365 extern void
 366 lto_codegen_dispose(lto_code_gen_t);
 367
 368 /**
 369  * Add an object module to the set of modules for which code will be generated.
 370  * Returns true on error (check lto_get_error_message() for details).
 371  *
 372  * \c cg and \c mod must both be in the same context.  See \a
 373  * lto_codegen_create_in_local_context() and \a
 374  * lto_module_create_in_codegen_context().
 375  *
 376  * \since prior to LTO_API_VERSION=3
 377  */
 378 extern lto_bool_t
 379 lto_codegen_add_module(lto_code_gen_t cg, lto_module_t mod);
 380
 381 /**
 382  * Sets the object module for code generation. This will transfer the ownership
 383  * of the module to the code generator.
 384  *
 385  * \c cg and \c mod must both be in the same context.
 386  *
 387  * \since LTO_API_VERSION=13
 388  */
 389 extern void
 390 lto_codegen_set_module(lto_code_gen_t cg, lto_module_t mod);
 391
 392 /**
 393  * Sets if debug info should be generated.
 394  * Returns true on error (check lto_get_error_message() for details).
 395  *
 396  * \since prior to LTO_API_VERSION=3
 397  */
 398 extern lto_bool_t
 399 lto_codegen_set_debug_model(lto_code_gen_t cg, lto_debug_model);
 400
 401 /**
 402  * Sets which PIC code model to generated.
 403  * Returns true on error (check lto_get_error_message() for details).
 404  *
 405  * \since prior to LTO_API_VERSION=3
 406  */
 407 extern lto_bool_t
 408 lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model);
 409
 410 /**
 411  * Sets the cpu to generate code for.
 412  *
 413  * \since LTO_API_VERSION=4
 414  */
 415 extern void
 416 lto_codegen_set_cpu(lto_code_gen_t cg, const char *cpu);
 417
 418 /**
 419  * Sets the location of the assembler tool to run. If not set, libLTO
 420  * will use gcc to invoke the assembler.
 421  *
 422  * \since LTO_API_VERSION=3
 423  */
 424 extern void
 425 lto_codegen_set_assembler_path(lto_code_gen_t cg, const char* path);
 426
 427 /**
 428  * Sets extra arguments that libLTO should pass to the assembler.
 429  *
 430  * \since LTO_API_VERSION=4
 431  */
 432 extern void
 433 lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args,
 434                                int nargs);
 435
 436 /**
 437  * Adds to a list of all global symbols that must exist in the final generated
 438  * code. If a function is not listed there, it might be inlined into every usage
 439  * and optimized away.
 440  *
 441  * \since prior to LTO_API_VERSION=3
 442  */
 443 extern void
 444 lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg, const char* symbol);
 445
 446 /**
 447  * Writes a new object file at the specified path that contains the
 448  * merged contents of all modules added so far.
 449  * Returns true on error (check lto_get_error_message() for details).
 450  *
 451  * \since LTO_API_VERSION=5
 452  */
 453 extern lto_bool_t
 454 lto_codegen_write_merged_modules(lto_code_gen_t cg, const char* path);
 455
 456 /**
 457  * Generates code for all added modules into one native object file.
 458  * This calls lto_codegen_optimize then lto_codegen_compile_optimized.
 459  *
 460  * On success returns a pointer to a generated mach-o/ELF buffer and
 461  * length set to the buffer size.  The buffer is owned by the
 462  * lto_code_gen_t and will be freed when lto_codegen_dispose()
 463  * is called, or lto_codegen_compile() is called again.
 464  * On failure, returns NULL (check lto_get_error_message() for details).
 465  *
 466  * \since prior to LTO_API_VERSION=3
 467  */
 468 extern const void*
 469 lto_codegen_compile(lto_code_gen_t cg, size_t* length);
 470
 471 /**
 472  * Generates code for all added modules into one native object file.
 473  * This calls lto_codegen_optimize then lto_codegen_compile_optimized (instead
 474  * of returning a generated mach-o/ELF buffer, it writes to a file).
 475  *
 476  * The name of the file is written to name. Returns true on error.
 477  *
 478  * \since LTO_API_VERSION=5
 479  */
 480 extern lto_bool_t
 481 lto_codegen_compile_to_file(lto_code_gen_t cg, const char** name);
 482
 483 /**
 484  * Runs optimization for the merged module. Returns true on error.
 485  *
 486  * \since LTO_API_VERSION=12
 487  */
 488 extern lto_bool_t
 489 lto_codegen_optimize(lto_code_gen_t cg);
 490
 491 /**
 492  * Generates code for the optimized merged module into one native object file.
 493  * It will not run any IR optimizations on the merged module.
 494  *
 495  * On success returns a pointer to a generated mach-o/ELF buffer and length set
 496  * to the buffer size.  The buffer is owned by the lto_code_gen_t and will be
 497  * freed when lto_codegen_dispose() is called, or
 498  * lto_codegen_compile_optimized() is called again. On failure, returns NULL
 499  * (check lto_get_error_message() for details).
 500  *
 501  * \since LTO_API_VERSION=12
 502  */
 503 extern const void*
 504 lto_codegen_compile_optimized(lto_code_gen_t cg, size_t* length);
 505
 506 /**
 507  * Returns the runtime API version.
 508  *
 509  * \since LTO_API_VERSION=12
 510  */
 511 extern unsigned int
 512 lto_api_version(void);
 513
 514 /**
 515  * Sets options to help debug codegen bugs.
 516  *
 517  * \since prior to LTO_API_VERSION=3
 518  */
 519 extern void
 520 lto_codegen_debug_options(lto_code_gen_t cg, const char *);
 521
 522 /**
 523  * Initializes LLVM disassemblers.
 524  * FIXME: This doesn't really belong here.
 525  *
 526  * \since LTO_API_VERSION=5
 527  */
 528 extern void
 529 lto_initialize_disassembler(void);
 530
 531 /**
 532  * Sets if we should run internalize pass during optimization and code
 533  * generation.
 534  *
 535  * \since LTO_API_VERSION=14
 536  */
 537 extern void
 538 lto_codegen_set_should_internalize(lto_code_gen_t cg,
 539                                    lto_bool_t ShouldInternalize);
 540
 541 /**
 542  * \brief Set whether to embed uselists in bitcode.
 543  *
 544  * Sets whether \a lto_codegen_write_merged_modules() should embed uselists in
 545  * output bitcode.  This should be turned on for all -save-temps output.
 546  *
 547  * \since LTO_API_VERSION=15
 548  */
 549 extern void
 550 lto_codegen_set_should_embed_uselists(lto_code_gen_t cg,
 551                                       lto_bool_t ShouldEmbedUselists);
 552
 553 /**
 554  * @} // endgoup LLVMCLTO
 555  * @defgroup LLVMCTLTO ThinLTO
 556  * @ingroup LLVMC
 557  *
 558  * @{
 559  */
 560
 561 /**
 562  * Type to wrap a single object returned by ThinLTO.
 563  *
 564  * \since LTO_API_VERSION=18
 565  */
 566 typedef struct {
 567   const char *Buffer;
 568   size_t Size;
 569 } LTOObjectBuffer;
 570
 571 /**
 572  * Instantiates a ThinLTO code generator.
 573  * Returns NULL on error (check lto_get_error_message() for details).
 574  *
 575  *
 576  * The ThinLTOCodeGenerator is not intended to be reuse for multiple
 577  * compilation: the model is that the client adds modules to the generator and
 578  * ask to perform the ThinLTO optimizations / codegen, and finally destroys the
 579  * codegenerator.
 580  *
 581  * \since LTO_API_VERSION=18
 582  */
 583 extern thinlto_code_gen_t thinlto_create_codegen(void);
 584
 585 /**
 586  * Frees the generator and all memory it internally allocated.
 587  * Upon return the thinlto_code_gen_t is no longer valid.
 588  *
 589  * \since LTO_API_VERSION=18
 590  */
 591 extern void thinlto_codegen_dispose(thinlto_code_gen_t cg);
 592
 593 /**
 594  * Add a module to a ThinLTO code generator. Identifier has to be unique among
 595  * all the modules in a code generator. The data buffer stays owned by the
 596  * client, and is expected to be available for the entire lifetime of the
 597  * thinlto_code_gen_t it is added to.
 598  *
 599  * On failure, returns NULL (check lto_get_error_message() for details).
 600  *
 601  *
 602  * \since LTO_API_VERSION=18
 603  */
 604 extern void thinlto_codegen_add_module(thinlto_code_gen_t cg,
 605                                        const char *identifier, const char *data,
 606                                        int length);
 607
 608 /**
 609  * Optimize and codegen all the modules added to the codegenerator using
 610  * ThinLTO. Resulting objects are accessible using thinlto_module_get_object().
 611  *
 612  * \since LTO_API_VERSION=18
 613  */
 614 extern void thinlto_codegen_process(thinlto_code_gen_t cg);
 615
 616 /**
 617  * Returns the number of object files produced by the ThinLTO CodeGenerator.
 618  *
 619  * It usually matches the number of input files, but this is not a guarantee of
 620  * the API and may change in future implementation, so the client should not
 621  * assume it.
 622  *
 623  * \since LTO_API_VERSION=18
 624  */
 625 extern unsigned int thinlto_module_get_num_objects(thinlto_code_gen_t cg);
 626
 627 /**
 628  * Returns a reference to the ith object file produced by the ThinLTO
 629  * CodeGenerator.
 630  *
 631  * Client should use \p thinlto_module_get_num_objects() to get the number of
 632  * available objects.
 633  *
 634  * \since LTO_API_VERSION=18
 635  */
 636 extern LTOObjectBuffer thinlto_module_get_object(thinlto_code_gen_t cg,
 637                                                  unsigned int index);
 638
 639 /**
 640  * Returns the number of object files produced by the ThinLTO CodeGenerator.
 641  *
 642  * It usually matches the number of input files, but this is not a guarantee of
 643  * the API and may change in future implementation, so the client should not
 644  * assume it.
 645  *
 646  * \since LTO_API_VERSION=21
 647  */
 648 unsigned int thinlto_module_get_num_object_files(thinlto_code_gen_t cg);
 649
 650 /**
 651  * Returns the path to the ith object file produced by the ThinLTO
 652  * CodeGenerator.
 653  *
 654  * Client should use \p thinlto_module_get_num_object_files() to get the number
 655  * of available objects.
 656  *
 657  * \since LTO_API_VERSION=21
 658  */
 659 const char *thinlto_module_get_object_file(thinlto_code_gen_t cg,
 660                                            unsigned int index);
 661
 662 /**
 663  * Sets which PIC code model to generate.
 664  * Returns true on error (check lto_get_error_message() for details).
 665  *
 666  * \since LTO_API_VERSION=18
 667  */
 668 extern lto_bool_t thinlto_codegen_set_pic_model(thinlto_code_gen_t cg,
 669                                                 lto_codegen_model);
 670
 671 /**
 672  * Sets the path to a directory to use as a storage for temporary bitcode files.
 673  * The intention is to make the bitcode files available for debugging at various
 674  * stage of the pipeline.
 675  *
 676  * \since LTO_API_VERSION=18
 677  */
 678 extern void thinlto_codegen_set_savetemps_dir(thinlto_code_gen_t cg,
 679                                               const char *save_temps_dir);
 680
 681 /**
 682  * Set the path to a directory where to save generated object files. This
 683  * path can be used by a linker to request on-disk files instead of in-memory
 684  * buffers. When set, results are available through
 685  * thinlto_module_get_object_file() instead of thinlto_module_get_object().
 686  *
 687  * \since LTO_API_VERSION=21
 688  */
 689 void thinlto_set_generated_objects_dir(thinlto_code_gen_t cg,
 690                                        const char *save_temps_dir);
 691
 692 /**
 693  * Sets the cpu to generate code for.
 694  *
 695  * \since LTO_API_VERSION=18
 696  */
 697 extern void thinlto_codegen_set_cpu(thinlto_code_gen_t cg, const char *cpu);
 698
 699 /**
 700  * Disable CodeGen, only run the stages till codegen and stop. The output will
 701  * be bitcode.
 702  *
 703  * \since LTO_API_VERSION=19
 704  */
 705 extern void thinlto_codegen_disable_codegen(thinlto_code_gen_t cg,
 706                                             lto_bool_t disable);
 707
 708 /**
 709  * Perform CodeGen only: disable all other stages.
 710  *
 711  * \since LTO_API_VERSION=19
 712  */
 713 extern void thinlto_codegen_set_codegen_only(thinlto_code_gen_t cg,
 714                                              lto_bool_t codegen_only);
 715
 716 /**
 717  * Parse -mllvm style debug options.
 718  *
 719  * \since LTO_API_VERSION=18
 720  */
 721 extern void thinlto_debug_options(const char *const *options, int number);
 722
 723 /**
 724  * Test if a module has support for ThinLTO linking.
 725  *
 726  * \since LTO_API_VERSION=18
 727  */
 728 extern lto_bool_t lto_module_is_thinlto(lto_module_t mod);
 729
 730 /**
 731  * Adds a symbol to the list of global symbols that must exist in the final
 732  * generated code. If a function is not listed there, it might be inlined into
 733  * every usage and optimized away. For every single module, the functions
 734  * referenced from code outside of the ThinLTO modules need to be added here.
 735  *
 736  * \since LTO_API_VERSION=18
 737  */
 738 extern void thinlto_codegen_add_must_preserve_symbol(thinlto_code_gen_t cg,
 739                                                      const char *name,
 740                                                      int length);
 741
 742 /**
 743  * Adds a symbol to the list of global symbols that are cross-referenced between
 744  * ThinLTO files. If the ThinLTO CodeGenerator can ensure that every
 745  * references from a ThinLTO module to this symbol is optimized away, then
 746  * the symbol can be discarded.
 747  *
 748  * \since LTO_API_VERSION=18
 749  */
 750 extern void thinlto_codegen_add_cross_referenced_symbol(thinlto_code_gen_t cg,
 751                                                         const char *name,
 752                                                         int length);
 753
 754 /**
 755  * @} // endgoup LLVMCTLTO
 756  * @defgroup LLVMCTLTO_CACHING ThinLTO Cache Control
 757  * @ingroup LLVMCTLTO
 758  *
 759  * These entry points control the ThinLTO cache. The cache is intended to
 760  * support incremental build, and thus needs to be persistent accross build.
 761  * The client enabled the cache by supplying a path to an existing directory.
 762  * The code generator will use this to store objects files that may be reused
 763  * during a subsequent build.
 764  * To avoid filling the disk space, a few knobs are provided:
 765  *  - The pruning interval limit the frequency at which the garbage collector
 766  *    will try to scan the cache directory to prune it from expired entries.
 767  *    Setting to -1 disable the pruning (default).
 768  *  - The pruning expiration time indicates to the garbage collector how old an
 769  *    entry needs to be to be removed.
 770  *  - Finally, the garbage collector can be instructed to prune the cache till
 771  *    the occupied space goes below a threshold.
 772  * @{
 773  */
 774
 775 /**
 776  * Sets the path to a directory to use as a cache storage for incremental build.
 777  * Setting this activates caching.
 778  *
 779  * \since LTO_API_VERSION=18
 780  */
 781 extern void thinlto_codegen_set_cache_dir(thinlto_code_gen_t cg,
 782                                           const char *cache_dir);
 783
 784 /**
 785  * Sets the cache pruning interval (in seconds). A negative value disable the
 786  * pruning. An unspecified default value will be applied, and a value of 0 will
 787  * be ignored.
 788  *
 789  * \since LTO_API_VERSION=18
 790  */
 791 extern void thinlto_codegen_set_cache_pruning_interval(thinlto_code_gen_t cg,
 792                                                        int interval);
 793
 794 /**
 795  * Sets the maximum cache size that can be persistent across build, in terms of
 796  * percentage of the available space on the the disk. Set to 100 to indicate
 797  * no limit, 50 to indicate that the cache size will not be left over half the
 798  * available space. A value over 100 will be reduced to 100, a value of 0 will
 799  * be ignored. An unspecified default value will be applied.
 800  *
 801  * The formula looks like:
 802  *  AvailableSpace = FreeSpace + ExistingCacheSize
 803  *  NewCacheSize = AvailableSpace * P/100
 804  *
 805  * \since LTO_API_VERSION=18
 806  */
 807 extern void thinlto_codegen_set_final_cache_size_relative_to_available_space(
 808     thinlto_code_gen_t cg, unsigned percentage);
 809
 810 /**
 811  * Sets the expiration (in seconds) for an entry in the cache. An unspecified
 812  * default value will be applied. A value of 0 will be ignored.
 813  *
 814  * \since LTO_API_VERSION=18
 815  */
 816 extern void thinlto_codegen_set_cache_entry_expiration(thinlto_code_gen_t cg,
 817                                                        unsigned expiration);
 818
 819 /**
 820  * @} // endgroup LLVMCTLTO_CACHING
 821  */
 822
 823 #ifdef __cplusplus
 824 }
 825 #endif
 826
 827 #endif /* LLVM_C_LTO_H */