| /* plugin-api.h -- External linker plugin API. */ |
| |
| /* Copyright (C) 2009-2020 Free Software Foundation, Inc. |
| Written by Cary Coutant <ccoutant@google.com>. |
| |
| This file is part of binutils. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| MA 02110-1301, USA. */ |
| |
| /* This file defines the interface for writing a linker plugin, which is |
| described at < http://gcc.gnu.org/wiki/whopr/driver >. */ |
| |
| #ifndef PLUGIN_API_H |
| #define PLUGIN_API_H |
| |
| #ifdef HAVE_STDINT_H |
| #include <stdint.h> |
| #elif defined(HAVE_INTTYPES_H) |
| #include <inttypes.h> |
| #endif |
| #include <sys/types.h> |
| #if !defined(HAVE_STDINT_H) && !defined(HAVE_INTTYPES_H) && \ |
| !defined(UINT64_MAX) && !defined(uint64_t) |
| #error cannot find uint64_t type |
| #endif |
| |
| /* Detect endianess based on __BYTE_ORDER__ macro. */ |
| #if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \ |
| defined(__ORDER_LITTLE_ENDIAN__) && defined(__ORDER_PDP_ENDIAN__) |
| #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
| #define PLUGIN_LITTLE_ENDIAN 1 |
| #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
| #define PLUGIN_BIG_ENDIAN 1 |
| #elif __BYTE_ORDER__ == __ORDER_PDP_ENDIAN__ |
| #define PLUGIN_PDP_ENDIAN 1 |
| #endif |
| #else |
| /* Older GCC releases (<4.6.0) can make detection from glibc macros. */ |
| #if defined(__GLIBC__) || defined(__GNU_LIBRARY__) || defined(__ANDROID__) |
| #include <endian.h> |
| #ifdef __BYTE_ORDER |
| #if __BYTE_ORDER == __LITTLE_ENDIAN |
| #define PLUGIN_LITTLE_ENDIAN 1 |
| #elif __BYTE_ORDER == __BIG_ENDIAN |
| #define PLUGIN_BIG_ENDIAN 1 |
| #endif |
| #endif |
| #endif |
| /* Include all necessary header files based on target. */ |
| #if defined(__SVR4) && defined(__sun) |
| #include <sys/byteorder.h> |
| #endif |
| #if defined(__FreeBSD__) || defined(__NetBSD__) || \ |
| defined(__DragonFly__) || defined(__minix) |
| #include <sys/endian.h> |
| #endif |
| #if defined(__OpenBSD__) |
| #include <machine/endian.h> |
| #endif |
| /* Detect endianess based on _BYTE_ORDER. */ |
| #ifdef _BYTE_ORDER |
| #if _BYTE_ORDER == _LITTLE_ENDIAN |
| #define PLUGIN_LITTLE_ENDIAN 1 |
| #elif _BYTE_ORDER == _BIG_ENDIAN |
| #define PLUGIN_BIG_ENDIAN 1 |
| #endif |
| #endif |
| /* Detect based on _WIN32. */ |
| #if defined(_WIN32) |
| #define PLUGIN_LITTLE_ENDIAN 1 |
| #endif |
| /* Detect based on __BIG_ENDIAN__ and __LITTLE_ENDIAN__ */ |
| #ifdef __LITTLE_ENDIAN__ |
| #define PLUGIN_LITTLE_ENDIAN 1 |
| #endif |
| #ifdef __BIG_ENDIAN__ |
| #define PLUGIN_BIG_ENDIAN 1 |
| #endif |
| #endif |
| |
| #ifdef __cplusplus |
| extern "C" |
| { |
| #endif |
| |
| /* Status code returned by most API routines. */ |
| |
| enum ld_plugin_status |
| { |
| LDPS_OK = 0, |
| LDPS_NO_SYMS, /* Attempt to get symbols that haven't been added. */ |
| LDPS_BAD_HANDLE, /* No claimed object associated with given handle. */ |
| LDPS_ERR |
| /* Additional Error codes TBD. */ |
| }; |
| |
| /* The version of the API specification. */ |
| |
| enum ld_plugin_api_version |
| { |
| LD_PLUGIN_API_VERSION = 1 |
| }; |
| |
| /* The type of output file being generated by the linker. */ |
| |
| enum ld_plugin_output_file_type |
| { |
| LDPO_REL, |
| LDPO_EXEC, |
| LDPO_DYN, |
| LDPO_PIE |
| }; |
| |
| /* An input file managed by the plugin library. */ |
| |
| struct ld_plugin_input_file |
| { |
| const char *name; |
| int fd; |
| off_t offset; |
| off_t filesize; |
| void *handle; |
| }; |
| |
| /* A symbol belonging to an input file managed by the plugin library. */ |
| |
| struct ld_plugin_symbol |
| { |
| char *name; |
| char *version; |
| /* This is for compatibility with older ABIs. The older ABI defined |
| only 'def' field. */ |
| #if PLUGIN_BIG_ENDIAN == 1 |
| char unused; |
| char section_kind; |
| char symbol_type; |
| char def; |
| #elif PLUGIN_LITTLE_ENDIAN == 1 |
| char def; |
| char symbol_type; |
| char section_kind; |
| char unused; |
| #elif PLUGIN_PDP_ENDIAN == 1 |
| char symbol_type; |
| char def; |
| char unused; |
| char section_kind; |
| #else |
| #error "Could not detect architecture endianess" |
| #endif |
| int visibility; |
| uint64_t size; |
| char *comdat_key; |
| int resolution; |
| }; |
| |
| /* An object's section. */ |
| |
| struct ld_plugin_section |
| { |
| const void* handle; |
| unsigned int shndx; |
| }; |
| |
| /* Whether the symbol is a definition, reference, or common, weak or not. */ |
| |
| enum ld_plugin_symbol_kind |
| { |
| LDPK_DEF, |
| LDPK_WEAKDEF, |
| LDPK_UNDEF, |
| LDPK_WEAKUNDEF, |
| LDPK_COMMON |
| }; |
| |
| /* The visibility of the symbol. */ |
| |
| enum ld_plugin_symbol_visibility |
| { |
| LDPV_DEFAULT, |
| LDPV_PROTECTED, |
| LDPV_INTERNAL, |
| LDPV_HIDDEN |
| }; |
| |
| /* The type of the symbol. */ |
| |
| enum ld_plugin_symbol_type |
| { |
| LDST_UNKNOWN, |
| LDST_FUNCTION, |
| LDST_VARIABLE |
| }; |
| |
| enum ld_plugin_symbol_section_kind |
| { |
| LDSSK_DEFAULT, |
| LDSSK_BSS |
| }; |
| |
| /* How a symbol is resolved. */ |
| |
| enum ld_plugin_symbol_resolution |
| { |
| LDPR_UNKNOWN = 0, |
| |
| /* Symbol is still undefined at this point. */ |
| LDPR_UNDEF, |
| |
| /* This is the prevailing definition of the symbol, with references from |
| regular object code. */ |
| LDPR_PREVAILING_DEF, |
| |
| /* This is the prevailing definition of the symbol, with no |
| references from regular objects. It is only referenced from IR |
| code. */ |
| LDPR_PREVAILING_DEF_IRONLY, |
| |
| /* This definition was pre-empted by a definition in a regular |
| object file. */ |
| LDPR_PREEMPTED_REG, |
| |
| /* This definition was pre-empted by a definition in another IR file. */ |
| LDPR_PREEMPTED_IR, |
| |
| /* This symbol was resolved by a definition in another IR file. */ |
| LDPR_RESOLVED_IR, |
| |
| /* This symbol was resolved by a definition in a regular object |
| linked into the main executable. */ |
| LDPR_RESOLVED_EXEC, |
| |
| /* This symbol was resolved by a definition in a shared object. */ |
| LDPR_RESOLVED_DYN, |
| |
| /* This is the prevailing definition of the symbol, with no |
| references from regular objects. It is only referenced from IR |
| code, but the symbol is exported and may be referenced from |
| a dynamic object (not seen at link time). */ |
| LDPR_PREVAILING_DEF_IRONLY_EXP |
| }; |
| |
| /* The plugin library's "claim file" handler. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_claim_file_handler) ( |
| const struct ld_plugin_input_file *file, int *claimed); |
| |
| /* The plugin library's "all symbols read" handler. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_all_symbols_read_handler) (void); |
| |
| /* The plugin library's cleanup handler. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_cleanup_handler) (void); |
| |
| /* The linker's interface for registering the "claim file" handler. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_register_claim_file) (ld_plugin_claim_file_handler handler); |
| |
| /* The linker's interface for registering the "all symbols read" handler. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_register_all_symbols_read) ( |
| ld_plugin_all_symbols_read_handler handler); |
| |
| /* The linker's interface for registering the cleanup handler. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_register_cleanup) (ld_plugin_cleanup_handler handler); |
| |
| /* The linker's interface for adding symbols from a claimed input file. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_add_symbols) (void *handle, int nsyms, |
| const struct ld_plugin_symbol *syms); |
| |
| /* The linker's interface for getting the input file information with |
| an open (possibly re-opened) file descriptor. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_input_file) (const void *handle, |
| struct ld_plugin_input_file *file); |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_view) (const void *handle, const void **viewp); |
| |
| /* The linker's interface for releasing the input file. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_release_input_file) (const void *handle); |
| |
| /* The linker's interface for retrieving symbol resolution information. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_symbols) (const void *handle, int nsyms, |
| struct ld_plugin_symbol *syms); |
| |
| /* The linker's interface for adding a compiled input file. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_add_input_file) (const char *pathname); |
| |
| /* The linker's interface for adding a library that should be searched. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_add_input_library) (const char *libname); |
| |
| /* The linker's interface for adding a library path that should be searched. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_set_extra_library_path) (const char *path); |
| |
| /* The linker's interface for issuing a warning or error message. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_message) (int level, const char *format, ...); |
| |
| /* The linker's interface for retrieving the number of sections in an object. |
| The handle is obtained in the claim_file handler. This interface should |
| only be invoked in the claim_file handler. This function sets *COUNT to |
| the number of sections in the object. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_input_section_count) (const void* handle, unsigned int *count); |
| |
| /* The linker's interface for retrieving the section type of a specific |
| section in an object. This interface should only be invoked in the |
| claim_file handler. This function sets *TYPE to an ELF SHT_xxx value. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_input_section_type) (const struct ld_plugin_section section, |
| unsigned int *type); |
| |
| /* The linker's interface for retrieving the name of a specific section in |
| an object. This interface should only be invoked in the claim_file handler. |
| This function sets *SECTION_NAME_PTR to a null-terminated buffer allocated |
| by malloc. The plugin must free *SECTION_NAME_PTR. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_input_section_name) (const struct ld_plugin_section section, |
| char **section_name_ptr); |
| |
| /* The linker's interface for retrieving the contents of a specific section |
| in an object. This interface should only be invoked in the claim_file |
| handler. This function sets *SECTION_CONTENTS to point to a buffer that is |
| valid until clam_file handler returns. It sets *LEN to the size of the |
| buffer. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_input_section_contents) (const struct ld_plugin_section section, |
| const unsigned char **section_contents, |
| size_t* len); |
| |
| /* The linker's interface for specifying the desired order of sections. |
| The sections should be specifed using the array SECTION_LIST in the |
| order in which they should appear in the final layout. NUM_SECTIONS |
| specifies the number of entries in each array. This should be invoked |
| in the all_symbols_read handler. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_update_section_order) (const struct ld_plugin_section *section_list, |
| unsigned int num_sections); |
| |
| /* The linker's interface for specifying that reordering of sections is |
| desired so that the linker can prepare for it. This should be invoked |
| before update_section_order, preferably in the claim_file handler. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_allow_section_ordering) (void); |
| |
| /* The linker's interface for specifying that a subset of sections is |
| to be mapped to a unique segment. If the plugin wants to call |
| unique_segment_for_sections, it must call this function from a |
| claim_file_handler or when it is first loaded. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_allow_unique_segment_for_sections) (void); |
| |
| /* The linker's interface for specifying that a specific set of sections |
| must be mapped to a unique segment. ELF segments do not have names |
| and the NAME is used as the name of the newly created output section |
| that is then placed in the unique PT_LOAD segment. FLAGS is used to |
| specify if any additional segment flags need to be set. For instance, |
| a specific segment flag can be set to identify this segment. Unsetting |
| segment flags that would be set by default is not possible. The |
| parameter SEGMENT_ALIGNMENT when non-zero will override the default. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_unique_segment_for_sections) ( |
| const char* segment_name, |
| uint64_t segment_flags, |
| uint64_t segment_alignment, |
| const struct ld_plugin_section * section_list, |
| unsigned int num_sections); |
| |
| /* The linker's interface for retrieving the section alignment requirement |
| of a specific section in an object. This interface should only be invoked in the |
| claim_file handler. This function sets *ADDRALIGN to the ELF sh_addralign |
| value of the input section. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_input_section_alignment) (const struct ld_plugin_section section, |
| unsigned int *addralign); |
| |
| /* The linker's interface for retrieving the section size of a specific section |
| in an object. This interface should only be invoked in the claim_file handler. |
| This function sets *SECSIZE to the ELF sh_size |
| value of the input section. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_input_section_size) (const struct ld_plugin_section section, |
| uint64_t *secsize); |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_new_input_handler) (const struct ld_plugin_input_file *file); |
| |
| /* The linker's interface for registering the "new_input" handler. This handler |
| will be notified when a new input file has been added after the |
| all_symbols_read event, allowing the plugin to, for example, set a unique |
| segment for sections in plugin-generated input files. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_register_new_input) (ld_plugin_new_input_handler handler); |
| |
| /* The linker's interface for getting the list of wrapped symbols using the |
| --wrap option. This sets *NUM_SYMBOLS to number of wrapped symbols and |
| *WRAP_SYMBOL_LIST to the list of wrapped symbols. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_get_wrap_symbols) (uint64_t *num_symbols, |
| const char ***wrap_symbol_list); |
| |
| enum ld_plugin_level |
| { |
| LDPL_INFO, |
| LDPL_WARNING, |
| LDPL_ERROR, |
| LDPL_FATAL |
| }; |
| |
| /* Values for the tv_tag field of the transfer vector. */ |
| |
| enum ld_plugin_tag |
| { |
| LDPT_NULL = 0, |
| LDPT_API_VERSION = 1, |
| LDPT_GOLD_VERSION = 2, |
| LDPT_LINKER_OUTPUT = 3, |
| LDPT_OPTION = 4, |
| LDPT_REGISTER_CLAIM_FILE_HOOK = 5, |
| LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK = 6, |
| LDPT_REGISTER_CLEANUP_HOOK = 7, |
| LDPT_ADD_SYMBOLS = 8, |
| LDPT_GET_SYMBOLS = 9, |
| LDPT_ADD_INPUT_FILE = 10, |
| LDPT_MESSAGE = 11, |
| LDPT_GET_INPUT_FILE = 12, |
| LDPT_RELEASE_INPUT_FILE = 13, |
| LDPT_ADD_INPUT_LIBRARY = 14, |
| LDPT_OUTPUT_NAME = 15, |
| LDPT_SET_EXTRA_LIBRARY_PATH = 16, |
| LDPT_GNU_LD_VERSION = 17, |
| LDPT_GET_VIEW = 18, |
| LDPT_GET_INPUT_SECTION_COUNT = 19, |
| LDPT_GET_INPUT_SECTION_TYPE = 20, |
| LDPT_GET_INPUT_SECTION_NAME = 21, |
| LDPT_GET_INPUT_SECTION_CONTENTS = 22, |
| LDPT_UPDATE_SECTION_ORDER = 23, |
| LDPT_ALLOW_SECTION_ORDERING = 24, |
| LDPT_GET_SYMBOLS_V2 = 25, |
| LDPT_ALLOW_UNIQUE_SEGMENT_FOR_SECTIONS = 26, |
| LDPT_UNIQUE_SEGMENT_FOR_SECTIONS = 27, |
| LDPT_GET_SYMBOLS_V3 = 28, |
| LDPT_GET_INPUT_SECTION_ALIGNMENT = 29, |
| LDPT_GET_INPUT_SECTION_SIZE = 30, |
| LDPT_REGISTER_NEW_INPUT_HOOK = 31, |
| LDPT_GET_WRAP_SYMBOLS = 32, |
| LDPT_ADD_SYMBOLS_V2 = 33 |
| }; |
| |
| /* The plugin transfer vector. */ |
| |
| struct ld_plugin_tv |
| { |
| enum ld_plugin_tag tv_tag; |
| union |
| { |
| int tv_val; |
| const char *tv_string; |
| ld_plugin_register_claim_file tv_register_claim_file; |
| ld_plugin_register_all_symbols_read tv_register_all_symbols_read; |
| ld_plugin_register_cleanup tv_register_cleanup; |
| ld_plugin_add_symbols tv_add_symbols; |
| ld_plugin_get_symbols tv_get_symbols; |
| ld_plugin_add_input_file tv_add_input_file; |
| ld_plugin_message tv_message; |
| ld_plugin_get_input_file tv_get_input_file; |
| ld_plugin_get_view tv_get_view; |
| ld_plugin_release_input_file tv_release_input_file; |
| ld_plugin_add_input_library tv_add_input_library; |
| ld_plugin_set_extra_library_path tv_set_extra_library_path; |
| ld_plugin_get_input_section_count tv_get_input_section_count; |
| ld_plugin_get_input_section_type tv_get_input_section_type; |
| ld_plugin_get_input_section_name tv_get_input_section_name; |
| ld_plugin_get_input_section_contents tv_get_input_section_contents; |
| ld_plugin_update_section_order tv_update_section_order; |
| ld_plugin_allow_section_ordering tv_allow_section_ordering; |
| ld_plugin_allow_unique_segment_for_sections tv_allow_unique_segment_for_sections; |
| ld_plugin_unique_segment_for_sections tv_unique_segment_for_sections; |
| ld_plugin_get_input_section_alignment tv_get_input_section_alignment; |
| ld_plugin_get_input_section_size tv_get_input_section_size; |
| ld_plugin_register_new_input tv_register_new_input; |
| ld_plugin_get_wrap_symbols tv_get_wrap_symbols; |
| } tv_u; |
| }; |
| |
| /* The plugin library's "onload" entry point. */ |
| |
| typedef |
| enum ld_plugin_status |
| (*ld_plugin_onload) (struct ld_plugin_tv *tv); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* !defined(PLUGIN_API_H) */ |