include/llvm-c/lto.h

   1 /*===-- llvm-c/lto.h - LTO Public C Interface ---------------------*- C -*-===*\
   2 |*                                                                            *|
   3 |* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
   4 |* Exceptions.                                                                *|
   5 |* See https://llvm.org/LICENSE.txt for license information.                  *|
   6 |* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
   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 25
  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  * 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  * 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  * 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  * 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 /** Opaque reference to an LTO input file */
 554 typedef struct LLVMOpaqueLTOInput *lto_input_t;
 555
 556 /**
 557   * Creates an LTO input file from a buffer. The path
 558   * argument is used for diagnotics as this function
 559   * otherwise does not know which file the given buffer
 560   * is associated with.
 561   *
 562   * \since LTO_API_VERSION=24
 563   */
 564 extern lto_input_t lto_input_create(const void *buffer,
 565                                     size_t buffer_size,
 566                                     const char *path);
 567
 568 /**
 569   * Frees all memory internally allocated by the LTO input file.
 570   * Upon return the lto_module_t is no longer valid.
 571   *
 572   * \since LTO_API_VERSION=24
 573   */
 574 extern void lto_input_dispose(lto_input_t input);
 575
 576 /**
 577   * Returns the number of dependent library specifiers
 578   * for the given LTO input file.
 579   *
 580   * \since LTO_API_VERSION=24
 581   */
 582 extern unsigned lto_input_get_num_dependent_libraries(lto_input_t input);
 583
 584 /**
 585   * Returns the ith dependent library specifier
 586   * for the given LTO input file. The returned
 587   * string is not null-terminated.
 588   *
 589   * \since LTO_API_VERSION=24
 590   */
 591 extern const char * lto_input_get_dependent_library(lto_input_t input,
 592                                                     size_t index,
 593                                                     size_t *size);
 594
 595 /**
 596  * Returns the list of libcall symbols that can be generated by LTO
 597  * that might not be visible from the symbol table of bitcode files.
 598  *
 599  * \since prior to LTO_API_VERSION=25
 600  */
 601 extern const char *const *lto_runtime_lib_symbols_list(size_t *size);
 602
 603 /**
 604  * @} // endgoup LLVMCLTO
 605  * @defgroup LLVMCTLTO ThinLTO
 606  * @ingroup LLVMC
 607  *
 608  * @{
 609  */
 610
 611 /**
 612  * Type to wrap a single object returned by ThinLTO.
 613  *
 614  * \since LTO_API_VERSION=18
 615  */
 616 typedef struct {
 617   const char *Buffer;
 618   size_t Size;
 619 } LTOObjectBuffer;
 620
 621 /**
 622  * Instantiates a ThinLTO code generator.
 623  * Returns NULL on error (check lto_get_error_message() for details).
 624  *
 625  *
 626  * The ThinLTOCodeGenerator is not intended to be reuse for multiple
 627  * compilation: the model is that the client adds modules to the generator and
 628  * ask to perform the ThinLTO optimizations / codegen, and finally destroys the
 629  * codegenerator.
 630  *
 631  * \since LTO_API_VERSION=18
 632  */
 633 extern thinlto_code_gen_t thinlto_create_codegen(void);
 634
 635 /**
 636  * Frees the generator and all memory it internally allocated.
 637  * Upon return the thinlto_code_gen_t is no longer valid.
 638  *
 639  * \since LTO_API_VERSION=18
 640  */
 641 extern void thinlto_codegen_dispose(thinlto_code_gen_t cg);
 642
 643 /**
 644  * Add a module to a ThinLTO code generator. Identifier has to be unique among
 645  * all the modules in a code generator. The data buffer stays owned by the
 646  * client, and is expected to be available for the entire lifetime of the
 647  * thinlto_code_gen_t it is added to.
 648  *
 649  * On failure, returns NULL (check lto_get_error_message() for details).
 650  *
 651  *
 652  * \since LTO_API_VERSION=18
 653  */
 654 extern void thinlto_codegen_add_module(thinlto_code_gen_t cg,
 655                                        const char *identifier, const char *data,
 656                                        int length);
 657
 658 /**
 659  * Optimize and codegen all the modules added to the codegenerator using
 660  * ThinLTO. Resulting objects are accessible using thinlto_module_get_object().
 661  *
 662  * \since LTO_API_VERSION=18
 663  */
 664 extern void thinlto_codegen_process(thinlto_code_gen_t cg);
 665
 666 /**
 667  * Returns the number of object files produced by the ThinLTO CodeGenerator.
 668  *
 669  * It usually matches the number of input files, but this is not a guarantee of
 670  * the API and may change in future implementation, so the client should not
 671  * assume it.
 672  *
 673  * \since LTO_API_VERSION=18
 674  */
 675 extern unsigned int thinlto_module_get_num_objects(thinlto_code_gen_t cg);
 676
 677 /**
 678  * Returns a reference to the ith object file produced by the ThinLTO
 679  * CodeGenerator.
 680  *
 681  * Client should use \p thinlto_module_get_num_objects() to get the number of
 682  * available objects.
 683  *
 684  * \since LTO_API_VERSION=18
 685  */
 686 extern LTOObjectBuffer thinlto_module_get_object(thinlto_code_gen_t cg,
 687                                                  unsigned int index);
 688
 689 /**
 690  * Returns the number of object files produced by the ThinLTO CodeGenerator.
 691  *
 692  * It usually matches the number of input files, but this is not a guarantee of
 693  * the API and may change in future implementation, so the client should not
 694  * assume it.
 695  *
 696  * \since LTO_API_VERSION=21
 697  */
 698 unsigned int thinlto_module_get_num_object_files(thinlto_code_gen_t cg);
 699
 700 /**
 701  * Returns the path to the ith object file produced by the ThinLTO
 702  * CodeGenerator.
 703  *
 704  * Client should use \p thinlto_module_get_num_object_files() to get the number
 705  * of available objects.
 706  *
 707  * \since LTO_API_VERSION=21
 708  */
 709 const char *thinlto_module_get_object_file(thinlto_code_gen_t cg,
 710                                            unsigned int index);
 711
 712 /**
 713  * Sets which PIC code model to generate.
 714  * Returns true on error (check lto_get_error_message() for details).
 715  *
 716  * \since LTO_API_VERSION=18
 717  */
 718 extern lto_bool_t thinlto_codegen_set_pic_model(thinlto_code_gen_t cg,
 719                                                 lto_codegen_model);
 720
 721 /**
 722  * Sets the path to a directory to use as a storage for temporary bitcode files.
 723  * The intention is to make the bitcode files available for debugging at various
 724  * stage of the pipeline.
 725  *
 726  * \since LTO_API_VERSION=18
 727  */
 728 extern void thinlto_codegen_set_savetemps_dir(thinlto_code_gen_t cg,
 729                                               const char *save_temps_dir);
 730
 731 /**
 732  * Set the path to a directory where to save generated object files. This
 733  * path can be used by a linker to request on-disk files instead of in-memory
 734  * buffers. When set, results are available through
 735  * thinlto_module_get_object_file() instead of thinlto_module_get_object().
 736  *
 737  * \since LTO_API_VERSION=21
 738  */
 739 void thinlto_set_generated_objects_dir(thinlto_code_gen_t cg,
 740                                        const char *save_temps_dir);
 741
 742 /**
 743  * Sets the cpu to generate code for.
 744  *
 745  * \since LTO_API_VERSION=18
 746  */
 747 extern void thinlto_codegen_set_cpu(thinlto_code_gen_t cg, const char *cpu);
 748
 749 /**
 750  * Disable CodeGen, only run the stages till codegen and stop. The output will
 751  * be bitcode.
 752  *
 753  * \since LTO_API_VERSION=19
 754  */
 755 extern void thinlto_codegen_disable_codegen(thinlto_code_gen_t cg,
 756                                             lto_bool_t disable);
 757
 758 /**
 759  * Perform CodeGen only: disable all other stages.
 760  *
 761  * \since LTO_API_VERSION=19
 762  */
 763 extern void thinlto_codegen_set_codegen_only(thinlto_code_gen_t cg,
 764                                              lto_bool_t codegen_only);
 765
 766 /**
 767  * Parse -mllvm style debug options.
 768  *
 769  * \since LTO_API_VERSION=18
 770  */
 771 extern void thinlto_debug_options(const char *const *options, int number);
 772
 773 /**
 774  * Test if a module has support for ThinLTO linking.
 775  *
 776  * \since LTO_API_VERSION=18
 777  */
 778 extern lto_bool_t lto_module_is_thinlto(lto_module_t mod);
 779
 780 /**
 781  * Adds a symbol to the list of global symbols that must exist in the final
 782  * generated code. If a function is not listed there, it might be inlined into
 783  * every usage and optimized away. For every single module, the functions
 784  * referenced from code outside of the ThinLTO modules need to be added here.
 785  *
 786  * \since LTO_API_VERSION=18
 787  */
 788 extern void thinlto_codegen_add_must_preserve_symbol(thinlto_code_gen_t cg,
 789                                                      const char *name,
 790                                                      int length);
 791
 792 /**
 793  * Adds a symbol to the list of global symbols that are cross-referenced between
 794  * ThinLTO files. If the ThinLTO CodeGenerator can ensure that every
 795  * references from a ThinLTO module to this symbol is optimized away, then
 796  * the symbol can be discarded.
 797  *
 798  * \since LTO_API_VERSION=18
 799  */
 800 extern void thinlto_codegen_add_cross_referenced_symbol(thinlto_code_gen_t cg,
 801                                                         const char *name,
 802                                                         int length);
 803
 804 /**
 805  * @} // endgoup LLVMCTLTO
 806  * @defgroup LLVMCTLTO_CACHING ThinLTO Cache Control
 807  * @ingroup LLVMCTLTO
 808  *
 809  * These entry points control the ThinLTO cache. The cache is intended to
 810  * support incremental builds, and thus needs to be persistent across builds.
 811  * The client enables the cache by supplying a path to an existing directory.
 812  * The code generator will use this to store objects files that may be reused
 813  * during a subsequent build.
 814  * To avoid filling the disk space, a few knobs are provided:
 815  *  - The pruning interval limits the frequency at which the garbage collector
 816  *    will try to scan the cache directory to prune expired entries.
 817  *    Setting to a negative number disables the pruning.
 818  *  - The pruning expiration time indicates to the garbage collector how old an
 819  *    entry needs to be to be removed.
 820  *  - Finally, the garbage collector can be instructed to prune the cache until
 821  *    the occupied space goes below a threshold.
 822  * @{
 823  */
 824
 825 /**
 826  * Sets the path to a directory to use as a cache storage for incremental build.
 827  * Setting this activates caching.
 828  *
 829  * \since LTO_API_VERSION=18
 830  */
 831 extern void thinlto_codegen_set_cache_dir(thinlto_code_gen_t cg,
 832                                           const char *cache_dir);
 833
 834 /**
 835  * Sets the cache pruning interval (in seconds). A negative value disables the
 836  * pruning. An unspecified default value will be applied, and a value of 0 will
 837  * force prunning to occur.
 838  *
 839  * \since LTO_API_VERSION=18
 840  */
 841 extern void thinlto_codegen_set_cache_pruning_interval(thinlto_code_gen_t cg,
 842                                                        int interval);
 843
 844 /**
 845  * Sets the maximum cache size that can be persistent across build, in terms of
 846  * percentage of the available space on the disk. Set to 100 to indicate
 847  * no limit, 50 to indicate that the cache size will not be left over half the
 848  * available space. A value over 100 will be reduced to 100, a value of 0 will
 849  * be ignored. An unspecified default value will be applied.
 850  *
 851  * The formula looks like:
 852  *  AvailableSpace = FreeSpace + ExistingCacheSize
 853  *  NewCacheSize = AvailableSpace * P/100
 854  *
 855  * \since LTO_API_VERSION=18
 856  */
 857 extern void thinlto_codegen_set_final_cache_size_relative_to_available_space(
 858     thinlto_code_gen_t cg, unsigned percentage);
 859
 860 /**
 861  * Sets the expiration (in seconds) for an entry in the cache. An unspecified
 862  * default value will be applied. A value of 0 will be ignored.
 863  *
 864  * \since LTO_API_VERSION=18
 865  */
 866 extern void thinlto_codegen_set_cache_entry_expiration(thinlto_code_gen_t cg,
 867                                                        unsigned expiration);
 868
 869 /**
 870  * Sets the maximum size of the cache directory (in bytes). A value over the
 871  * amount of available space on the disk will be reduced to the amount of
 872  * available space. An unspecified default value will be applied. A value of 0
 873  * will be ignored.
 874  *
 875  * \since LTO_API_VERSION=22
 876  */
 877 extern void thinlto_codegen_set_cache_size_bytes(thinlto_code_gen_t cg,
 878                                                  unsigned max_size_bytes);
 879
 880 /**
 881  * Same as thinlto_codegen_set_cache_size_bytes, except the maximum size is in
 882  * megabytes (2^20 bytes).
 883  *
 884  * \since LTO_API_VERSION=23
 885  */
 886 extern void
 887 thinlto_codegen_set_cache_size_megabytes(thinlto_code_gen_t cg,
 888                                          unsigned max_size_megabytes);
 889
 890 /**
 891  * Sets the maximum number of files in the cache directory. An unspecified
 892  * default value will be applied. A value of 0 will be ignored.
 893  *
 894  * \since LTO_API_VERSION=22
 895  */
 896 extern void thinlto_codegen_set_cache_size_files(thinlto_code_gen_t cg,
 897                                                  unsigned max_size_files);
 898
 899 /**
 900  * @} // endgroup LLVMCTLTO_CACHING
 901  */
 902
 903 #ifdef __cplusplus
 904 }
 905 #endif
 906
 907 #endif /* LLVM_C_LTO_H */