llvm/include/llvm-c/lto.h

/*===-- llvm-c/lto.h - LTO Public C Interface ---------------------*- C -*-===*\
|*                                                                            *|
|*                     The LLVM Compiler Infrastructure                       *|
|*                                                                            *|
|* This file is distributed under the University of Illinois Open Source      *|
|* License. See LICENSE.TXT for details.                                      *|
|*                                                                            *|
|*===----------------------------------------------------------------------===*|
|*                                                                            *|
|* This header provides public interface to an abstract link time optimization*|
|* library.  LLVM provides an implementation of this interface for use with   *|
|* llvm bitcode files.                                                        *|
|*                                                                            *|
\*===----------------------------------------------------------------------===*/

#ifndef LLVM_C_LTO_H
#define LLVM_C_LTO_H

#include <stddef.h>
#include <sys/types.h>

#ifndef __cplusplus
#if !defined(_MSC_VER)
#include <stdbool.h>
typedef bool lto_bool_t;
#else
/* MSVC in particular does not have anything like _Bool or bool in C, but we can
   at least make sure the type is the same size.  The implementation side will
   use C++ bool. */
typedef unsigned char lto_bool_t;
#endif
#else
typedef bool lto_bool_t;
#endif

/**
 * @defgroup LLVMCLTO LTO
 * @ingroup LLVMC
 *
 * @{
 */

#define LTO_API_VERSION 17

/**
 * \since prior to LTO_API_VERSION=3
 */
typedef enum {
    LTO_SYMBOL_ALIGNMENT_MASK              = 0x0000001F, /* log2 of alignment */
    LTO_SYMBOL_PERMISSIONS_MASK            = 0x000000E0,
    LTO_SYMBOL_PERMISSIONS_CODE            = 0x000000A0,
    LTO_SYMBOL_PERMISSIONS_DATA            = 0x000000C0,
    LTO_SYMBOL_PERMISSIONS_RODATA          = 0x00000080,
    LTO_SYMBOL_DEFINITION_MASK             = 0x00000700,
    LTO_SYMBOL_DEFINITION_REGULAR          = 0x00000100,
    LTO_SYMBOL_DEFINITION_TENTATIVE        = 0x00000200,
    LTO_SYMBOL_DEFINITION_WEAK             = 0x00000300,
    LTO_SYMBOL_DEFINITION_UNDEFINED        = 0x00000400,
    LTO_SYMBOL_DEFINITION_WEAKUNDEF        = 0x00000500,
    LTO_SYMBOL_SCOPE_MASK                  = 0x00003800,
    LTO_SYMBOL_SCOPE_INTERNAL              = 0x00000800,
    LTO_SYMBOL_SCOPE_HIDDEN                = 0x00001000,
    LTO_SYMBOL_SCOPE_PROTECTED             = 0x00002000,
    LTO_SYMBOL_SCOPE_DEFAULT               = 0x00001800,
    LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN = 0x00002800,
    LTO_SYMBOL_COMDAT                      = 0x00004000,
    LTO_SYMBOL_ALIAS                       = 0x00008000
} lto_symbol_attributes;

/**
 * \since prior to LTO_API_VERSION=3
 */
typedef enum {
    LTO_DEBUG_MODEL_NONE         = 0,
    LTO_DEBUG_MODEL_DWARF        = 1
} lto_debug_model;

/**
 * \since prior to LTO_API_VERSION=3
 */
typedef enum {
    LTO_CODEGEN_PIC_MODEL_STATIC         = 0,
    LTO_CODEGEN_PIC_MODEL_DYNAMIC        = 1,
    LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC = 2,
    LTO_CODEGEN_PIC_MODEL_DEFAULT        = 3
} lto_codegen_model;

/** opaque reference to a loaded object module */
typedef struct LLVMOpaqueLTOModule *lto_module_t;

/** opaque reference to a code generator */
typedef struct LLVMOpaqueLTOCodeGenerator *lto_code_gen_t;

#ifdef __cplusplus
extern "C" {
#endif

/**
 * Returns a printable string.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern const char*
lto_get_version(void);


/**
 * Returns the last error string or NULL if last operation was successful.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern const char*
lto_get_error_message(void);

/**
 * Checks if a file is a loadable object file.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_bool_t
lto_module_is_object_file(const char* path);


/**
 * Checks if a file is a loadable object compiled for requested target.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_bool_t
lto_module_is_object_file_for_target(const char* path,
                                     const char* target_triple_prefix);


/**
 * Checks if a buffer is a loadable object file.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_bool_t
lto_module_is_object_file_in_memory(const void* mem, size_t length);


/**
 * Checks if a buffer is a loadable object compiled for requested target.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_bool_t
lto_module_is_object_file_in_memory_for_target(const void* mem, size_t length,
                                              const char* target_triple_prefix);


/**
 * Loads an object file from disk.
 * Returns NULL on error (check lto_get_error_message() for details).
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_module_t
lto_module_create(const char* path);


/**
 * Loads an object file from memory.
 * Returns NULL on error (check lto_get_error_message() for details).
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_module_t
lto_module_create_from_memory(const void* mem, size_t length);

/**
 * Loads an object file from memory with an extra path argument.
 * Returns NULL on error (check lto_get_error_message() for details).
 *
 * \since LTO_API_VERSION=9
 */
extern lto_module_t
lto_module_create_from_memory_with_path(const void* mem, size_t length,
                                        const char *path);

/**
 * \brief Loads an object file in its own context.
 *
 * Loads an object file in its own LLVMContext.  This function call is
 * thread-safe.  However, modules created this way should not be merged into an
 * lto_code_gen_t using \a lto_codegen_add_module().
 *
 * Returns NULL on error (check lto_get_error_message() for details).
 *
 * \since LTO_API_VERSION=11
 */
extern lto_module_t
lto_module_create_in_local_context(const void *mem, size_t length,
                                   const char *path);

/**
 * \brief Loads an object file in the codegen context.
 *
 * Loads an object file into the same context as \c cg.  The module is safe to
 * add using \a lto_codegen_add_module().
 *
 * Returns NULL on error (check lto_get_error_message() for details).
 *
 * \since LTO_API_VERSION=11
 */
extern lto_module_t
lto_module_create_in_codegen_context(const void *mem, size_t length,
                                     const char *path, lto_code_gen_t cg);

/**
 * Loads an object file from disk. The seek point of fd is not preserved.
 * Returns NULL on error (check lto_get_error_message() for details).
 *
 * \since LTO_API_VERSION=5
 */
extern lto_module_t
lto_module_create_from_fd(int fd, const char *path, size_t file_size);

/**
 * Loads an object file from disk. The seek point of fd is not preserved.
 * Returns NULL on error (check lto_get_error_message() for details).
 *
 * \since LTO_API_VERSION=5
 */
extern lto_module_t
lto_module_create_from_fd_at_offset(int fd, const char *path, size_t file_size,
                                    size_t map_size, off_t offset);

/**
 * Frees all memory internally allocated by the module.
 * Upon return the lto_module_t is no longer valid.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern void
lto_module_dispose(lto_module_t mod);

/**
 * Returns triple string which the object module was compiled under.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern const char*
lto_module_get_target_triple(lto_module_t mod);

/**
 * Sets triple string with which the object will be codegened.
 *
 * \since LTO_API_VERSION=4
 */
extern void
lto_module_set_target_triple(lto_module_t mod, const char *triple);


/**
 * Returns the number of symbols in the object module.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern unsigned int
lto_module_get_num_symbols(lto_module_t mod);


/**
 * Returns the name of the ith symbol in the object module.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern const char*
lto_module_get_symbol_name(lto_module_t mod, unsigned int index);


/**
 * Returns the attributes of the ith symbol in the object module.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_symbol_attributes
lto_module_get_symbol_attribute(lto_module_t mod, unsigned int index);


/**
 * Returns the module's linker options.
 *
 * The linker options may consist of multiple flags. It is the linker's
 * responsibility to split the flags using a platform-specific mechanism.
 *
 * \since LTO_API_VERSION=16
 */
extern const char*
lto_module_get_linkeropts(lto_module_t mod);


/**
 * Diagnostic severity.
 *
 * \since LTO_API_VERSION=7
 */
typedef enum {
  LTO_DS_ERROR = 0,
  LTO_DS_WARNING = 1,
  LTO_DS_REMARK = 3, // Added in LTO_API_VERSION=10.
  LTO_DS_NOTE = 2
} lto_codegen_diagnostic_severity_t;

/**
 * Diagnostic handler type.
 * \p severity defines the severity.
 * \p diag is the actual diagnostic.
 * The diagnostic is not prefixed by any of severity keyword, e.g., 'error: '.
 * \p ctxt is used to pass the context set with the diagnostic handler.
 *
 * \since LTO_API_VERSION=7
 */
typedef void (*lto_diagnostic_handler_t)(
    lto_codegen_diagnostic_severity_t severity, const char *diag, void *ctxt);

/**
 * Set a diagnostic handler and the related context (void *).
 * This is more general than lto_get_error_message, as the diagnostic handler
 * can be called at anytime within lto.
 *
 * \since LTO_API_VERSION=7
 */
extern void lto_codegen_set_diagnostic_handler(lto_code_gen_t,
                                               lto_diagnostic_handler_t,
                                               void *);

/**
 * Instantiates a code generator.
 * Returns NULL on error (check lto_get_error_message() for details).
 *
 * All modules added using \a lto_codegen_add_module() must have been created
 * in the same context as the codegen.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_code_gen_t
lto_codegen_create(void);

/**
 * \brief Instantiate a code generator in its own context.
 *
 * Instantiates a code generator in its own context.  Modules added via \a
 * lto_codegen_add_module() must have all been created in the same context,
 * using \a lto_module_create_in_codegen_context().
 *
 * \since LTO_API_VERSION=11
 */
extern lto_code_gen_t
lto_codegen_create_in_local_context(void);

/**
 * Frees all code generator and all memory it internally allocated.
 * Upon return the lto_code_gen_t is no longer valid.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern void
lto_codegen_dispose(lto_code_gen_t);

/**
 * Add an object module to the set of modules for which code will be generated.
 * Returns true on error (check lto_get_error_message() for details).
 *
 * \c cg and \c mod must both be in the same context.  See \a
 * lto_codegen_create_in_local_context() and \a
 * lto_module_create_in_codegen_context().
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_bool_t
lto_codegen_add_module(lto_code_gen_t cg, lto_module_t mod);

/**
 * Sets the object module for code generation. This will transfer the ownship of
 * the module to code generator.
 *
 * \c cg and \c mod must both be in the same context.
 *
 * \since LTO_API_VERSION=13
 */
extern void
lto_codegen_set_module(lto_code_gen_t cg, lto_module_t mod);

/**
 * Sets if debug info should be generated.
 * Returns true on error (check lto_get_error_message() for details).
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_bool_t
lto_codegen_set_debug_model(lto_code_gen_t cg, lto_debug_model);


/**
 * Sets which PIC code model to generated.
 * Returns true on error (check lto_get_error_message() for details).
 *
 * \since prior to LTO_API_VERSION=3
 */
extern lto_bool_t
lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model);


/**
 * Sets the cpu to generate code for.
 *
 * \since LTO_API_VERSION=4
 */
extern void
lto_codegen_set_cpu(lto_code_gen_t cg, const char *cpu);


/**
 * Sets the location of the assembler tool to run. If not set, libLTO
 * will use gcc to invoke the assembler.
 *
 * \since LTO_API_VERSION=3
 */
extern void
lto_codegen_set_assembler_path(lto_code_gen_t cg, const char* path);

/**
 * Sets extra arguments that libLTO should pass to the assembler.
 *
 * \since LTO_API_VERSION=4
 */
extern void
lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args,
                               int nargs);

/**
 * Adds to a list of all global symbols that must exist in the final generated
 * code. If a function is not listed there, it might be inlined into every usage
 * and optimized away.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern void
lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg, const char* symbol);

/**
 * Writes a new object file at the specified path that contains the
 * merged contents of all modules added so far.
 * Returns true on error (check lto_get_error_message() for details).
 *
 * \since LTO_API_VERSION=5
 */
extern lto_bool_t
lto_codegen_write_merged_modules(lto_code_gen_t cg, const char* path);

/**
 * Generates code for all added modules into one native object file.
 * This calls lto_codegen_optimize then lto_codegen_compile_optimized.
 *
 * On success returns a pointer to a generated mach-o/ELF buffer and
 * length set to the buffer size.  The buffer is owned by the
 * lto_code_gen_t and will be freed when lto_codegen_dispose()
 * is called, or lto_codegen_compile() is called again.
 * On failure, returns NULL (check lto_get_error_message() for details).
 *
 * \since prior to LTO_API_VERSION=3
 */
extern const void*
lto_codegen_compile(lto_code_gen_t cg, size_t* length);

/**
 * Generates code for all added modules into one native object file.
 * This calls lto_codegen_optimize then lto_codegen_compile_optimized (instead
 * of returning a generated mach-o/ELF buffer, it writes to a file).
 *
 * The name of the file is written to name. Returns true on error.
 *
 * \since LTO_API_VERSION=5
 */
extern lto_bool_t
lto_codegen_compile_to_file(lto_code_gen_t cg, const char** name);

/**
 * Runs optimization for the merged module. Returns true on error.
 *
 * \since LTO_API_VERSION=12
 */
extern lto_bool_t
lto_codegen_optimize(lto_code_gen_t cg);

/**
 * Generates code for the optimized merged module into one native object file.
 * It will not run any IR optimizations on the merged module.
 *
 * On success returns a pointer to a generated mach-o/ELF buffer and length set
 * to the buffer size.  The buffer is owned by the lto_code_gen_t and will be
 * freed when lto_codegen_dispose() is called, or
 * lto_codegen_compile_optimized() is called again. On failure, returns NULL
 * (check lto_get_error_message() for details).
 *
 * \since LTO_API_VERSION=12
 */
extern const void*
lto_codegen_compile_optimized(lto_code_gen_t cg, size_t* length);

/**
 * Returns the runtime API version.
 *
 * \since LTO_API_VERSION=12
 */
extern unsigned int
lto_api_version(void);

/**
 * Sets options to help debug codegen bugs.
 *
 * \since prior to LTO_API_VERSION=3
 */
extern void
lto_codegen_debug_options(lto_code_gen_t cg, const char *);

/**
 * Initializes LLVM disassemblers.
 * FIXME: This doesn't really belong here.
 *
 * \since LTO_API_VERSION=5
 */
extern void
lto_initialize_disassembler(void);

/**
 * Sets if we should run internalize pass during optimization and code
 * generation.
 *
 * \since LTO_API_VERSION=14
 */
extern void
lto_codegen_set_should_internalize(lto_code_gen_t cg,
                                   lto_bool_t ShouldInternalize);

/**
 * \brief Set whether to embed uselists in bitcode.
 *
 * Sets whether \a lto_codegen_write_merged_modules() should embed uselists in
 * output bitcode.  This should be turned on for all -save-temps output.
 *
 * \since LTO_API_VERSION=15
 */
extern void
lto_codegen_set_should_embed_uselists(lto_code_gen_t cg,
                                      lto_bool_t ShouldEmbedUselists);

#ifdef __cplusplus
}
#endif

/**
 * @}
 */

#endif