llvm/include/llvm-c/lto.h
Mehdi Amini 51f5548e2a Add a libLTO API to stop/restart ThinLTO between optimizations and CodeGen
This allows the linker to instruct ThinLTO to perform only the
optimization part or only the codegen part of the process.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265113 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-01 06:47:02 +00:00

785 lines
23 KiB
C

/*===-- 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
#ifdef __cplusplus
#include <cstddef>
#else
#include <stddef.h>
#endif
#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 19
/**
* \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;
/** opaque reference to a thin code generator */
typedef struct LLVMOpaqueThinLTOCodeGenerator *thinlto_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 ownership
* of the module to the 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);
/**
* @}
* @defgroup LLVMCTLTO ThinLTO
* @ingroup LLVMC
*
* @{
*/
/**
* Type to wrap a single object returned by ThinLTO.
*
* \since LTO_API_VERSION=18
*/
typedef struct {
const char *Buffer;
size_t Size;
} LTOObjectBuffer;
/**
* Instantiates a ThinLTO code generator.
* Returns NULL on error (check lto_get_error_message() for details).
*
*
* The ThinLTOCodeGenerator is not intended to be reuse for multiple
* compilation: the model is that the client adds modules to the generator and
* ask to perform the ThinLTO optimizations / codegen, and finally destroys the
* codegenerator.
*
* \since LTO_API_VERSION=18
*/
extern thinlto_code_gen_t thinlto_create_codegen(void);
/**
* Frees the generator and all memory it internally allocated.
* Upon return the thinlto_code_gen_t is no longer valid.
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_dispose(thinlto_code_gen_t cg);
/**
* Add a module to a ThinLTO code generator. Identifier has to be unique among
* all the modules in a code generator. The data buffer stays owned by the
* client, and is expected to be available for the entire lifetime of the
* thinlto_code_gen_t it is added to.
*
* On failure, returns NULL (check lto_get_error_message() for details).
*
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_add_module(thinlto_code_gen_t cg,
const char *identifier, const char *data,
int length);
/**
* Optimize and codegen all the modules added to the codegenerator using
* ThinLTO. Resulting objects are accessible using thinlto_module_get_object().
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_process(thinlto_code_gen_t cg);
/**
* Returns the number of object files produced by the ThinLTO CodeGenerator.
*
* It usually matches the number of input files, but this is not a guarantee of
* the API and may change in future implementation, so the client should not
* assume it.
*
* \since LTO_API_VERSION=18
*/
extern unsigned int thinlto_module_get_num_objects(thinlto_code_gen_t cg);
/**
* Returns a reference to the ith object file produced by the ThinLTO
* CodeGenerator.
*
* Client should use \p thinlto_module_get_num_objects() to get the number of
* available objects.
*
* \since LTO_API_VERSION=18
*/
extern LTOObjectBuffer thinlto_module_get_object(thinlto_code_gen_t cg,
unsigned int index);
/**
* Sets which PIC code model to generate.
* Returns true on error (check lto_get_error_message() for details).
*
* \since LTO_API_VERSION=18
*/
extern lto_bool_t thinlto_codegen_set_pic_model(thinlto_code_gen_t cg,
lto_codegen_model);
/**
* @}
* @defgroup LLVMCTLTO_CACHING ThinLTO Cache Control
* @ingroup LLVMCTLTO
*
* These entry points control the ThinLTO cache. The cache is intended to
* support incremental build, and thus needs to be persistent accross build.
* The client enabled the cache by supplying a path to an existing directory.
* The code generator will use this to store objects files that may be reused
* during a subsequent build.
* To avoid filling the disk space, a few knobs are provided:
* - The pruning interval limit the frequency at which the garbage collector
* will try to scan the cache directory to prune it from expired entries.
* Setting to -1 disable the pruning (default).
* - The pruning expiration time indicates to the garbage collector how old an
* entry needs to be to be removed.
* - Finally, the garbage collector can be instructed to prune the cache till
* the occupied space goes below a threshold.
* @{
*/
/**
* Sets the path to a directory to use as a cache storage for incremental build.
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_set_cache_dir(thinlto_code_gen_t cg,
const char *cache_dir);
/**
* Sets the cache pruning interval (in seconds). A negative value disable the
* pruning (default).
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_set_cache_pruning_interval(thinlto_code_gen_t cg,
int interval);
/**
* Sets the maximum cache size that can be persistent across build, in terms of
* percentage of the available space on the the disk. Set to 100 to indicate
* no limit, 50 to indicate that the cache size will not be left over half the
* available space. A value over 100 will be reduced to 100.
*
* The formula looks like:
* AvailableSpace = FreeSpace + ExistingCacheSize
* NewCacheSize = AvailableSpace * P/100
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_set_final_cache_size_relative_to_available_space(
thinlto_code_gen_t cg, unsigned percentage);
/**
* Sets the expiration (in seconds) for an entry in the cache.
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_set_cache_entry_expiration(thinlto_code_gen_t cg,
unsigned expiration);
/**
* @}
*/
/**
* Sets the path to a directory to use as a storage for temporary bitcode files.
* The intention is to make the bitcode files available for debugging at various
* stage of the pipeline.
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_set_savetemps_dir(thinlto_code_gen_t cg,
const char *save_temps_dir);
/**
* Sets the cpu to generate code for.
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_set_cpu(thinlto_code_gen_t cg, const char *cpu);
/**
* Disable CodeGen, only run the stages till codegen and stop. The output will
* be bitcode.
*
* \since LTO_API_VERSION=19
*/
extern void thinlto_codegen_disable_codegen(thinlto_code_gen_t cg,
lto_bool_t disable);
/**
* Perform CodeGen only: disable all other stages.
*
* \since LTO_API_VERSION=19
*/
extern void thinlto_codegen_set_codegen_only(thinlto_code_gen_t cg,
lto_bool_t codegen_only);
/**
* Parse -mllvm style debug options.
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_debug_options(const char *const *options, int number);
/**
* Test if a module has support for ThinLTO linking.
*
* \since LTO_API_VERSION=18
*/
extern lto_bool_t lto_module_is_thinlto(lto_module_t mod);
/**
* Adds a symbol to the list of 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. For every single module, the functions
* referenced from code outside of the ThinLTO modules need to be added here.
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_add_must_preserve_symbol(thinlto_code_gen_t cg,
const char *name,
int length);
/**
* Adds a symbol to the list of global symbols that are cross-referenced between
* ThinLTO files. If the ThinLTO CodeGenerator can ensure that every
* references from a ThinLTO module to this symbol is optimized away, then
* the symbol can be discarded.
*
* \since LTO_API_VERSION=18
*/
extern void thinlto_codegen_add_cross_referenced_symbol(thinlto_code_gen_t cg,
const char *name,
int length);
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* LLVM_C_LTO_H */