llvm/include/llvm-c/lto.h
Rafael Espindola 7e667c56cf Use LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN instead of the "dso list".
There are two ways one could implement hiding of linkonce_odr symbols in LTO:
* LLVM tells the linker which symbols can be hidden if not used from native
  files.
* The linker tells LLVM which symbols are not used from other object files,
  but will be put in the dso symbol table if present.

GOLD's API is the second option. It was implemented almost 1:1 in llvm by
passing the list down to internalize.

LLVM already had partial support for the first option. It is also very similar
to how ld64 handles hiding these symbols when *not* doing LTO.

This patch then
* removes the APIs for the DSO list.
* marks LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN all linkonce_odr unnamed_addr
  global values and other linkonce_odr whose address is not used.
* makes the gold plugin responsible for handling the API mismatch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193800 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-31 20:51:58 +00:00

322 lines
8.9 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
#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 5
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_attributes;
typedef enum {
LTO_DEBUG_MODEL_NONE = 0,
LTO_DEBUG_MODEL_DWARF = 1
} lto_debug_model;
typedef enum {
LTO_CODEGEN_PIC_MODEL_STATIC = 0,
LTO_CODEGEN_PIC_MODEL_DYNAMIC = 1,
LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC = 2
} lto_codegen_model;
/** opaque reference to a loaded object module */
typedef struct LTOModule* lto_module_t;
/** opaque reference to a code generator */
typedef struct LTOCodeGenerator* lto_code_gen_t;
#ifdef __cplusplus
extern "C" {
#endif
/**
* Returns a printable string.
*/
extern const char*
lto_get_version(void);
/**
* Returns the last error string or NULL if last operation was successful.
*/
extern const char*
lto_get_error_message(void);
/**
* Checks if a file is a loadable object file.
*/
extern lto_bool_t
lto_module_is_object_file(const char* path);
/**
* Checks if a file is a loadable object compiled for requested target.
*/
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.
*/
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.
*/
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).
*/
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).
*/
extern lto_module_t
lto_module_create_from_memory(const void* mem, size_t length);
/**
* 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).
*/
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).
*/
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.
*/
extern void
lto_module_dispose(lto_module_t mod);
/**
* Returns triple string which the object module was compiled under.
*/
extern const char*
lto_module_get_target_triple(lto_module_t mod);
/**
* Sets triple string with which the object will be codegened.
*/
extern void
lto_module_set_target_triple(lto_module_t mod, const char *triple);
/**
* Returns the number of symbols in the object module.
*/
extern unsigned int
lto_module_get_num_symbols(lto_module_t mod);
/**
* Returns the name of the ith symbol in the object module.
*/
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.
*/
extern lto_symbol_attributes
lto_module_get_symbol_attribute(lto_module_t mod, unsigned int index);
/**
* Instantiates a code generator.
* Returns NULL on error (check lto_get_error_message() for details).
*/
extern lto_code_gen_t
lto_codegen_create(void);
/**
* Frees all code generator and all memory it internally allocated.
* Upon return the lto_code_gen_t is no longer valid.
*/
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).
*/
extern lto_bool_t
lto_codegen_add_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).
*/
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).
*/
extern lto_bool_t
lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model);
/**
* Sets the cpu to generate code for.
*/
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.
*/
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.
*/
extern void
lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args,
int nargs);
/**
* Tells LTO optimization passes that this symbol must be preserved
* because it is referenced by native code or a command line option.
*/
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).
*/
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.
* 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).
*/
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.
* The name of the file is written to name. Returns true on error.
*/
extern lto_bool_t
lto_codegen_compile_to_file(lto_code_gen_t cg, const char** name);
/**
* Sets options to help debug codegen bugs.
*/
extern void
lto_codegen_debug_options(lto_code_gen_t cg, const char *);
/**
* Initializes LLVM disassemblers.
* FIXME: This doesn't really belong here.
*/
extern void
lto_initialize_disassembler(void);
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif