include/plugin-api.h

   1 /* plugin-api.h -- External linker plugin API.  */
   2
   3 /* Copyright 2009 Free Software Foundation, Inc.
   4    Written by Cary Coutant <ccoutant@google.com>.
   5
   6    This file is part of binutils.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21    MA 02110-1301, USA.  */
  22
  23 /* This file defines the interface for writing a linker plugin, which is
  24    described at < http://gcc.gnu.org/wiki/whopr/driver >.  */
  25
  26 #ifndef PLUGIN_API_H
  27 #define PLUGIN_API_H
  28
  29 #include <stdint.h>
  30 #include <sys/types.h>
  31
  32 #ifdef __cplusplus
  33 extern "C"
  34 {
  35 #endif
  36
  37 /* Status code returned by most API routines.  */
  38
  39 enum ld_plugin_status
  40 {
  41   LDPS_OK = 0,
  42   LDPS_NO_SYMS,         /* Attempt to get symbols that haven't been added. */
  43   LDPS_BAD_HANDLE,      /* No claimed object associated with given handle. */
  44   LDPS_ERR
  45   /* Additional Error codes TBD.  */
  46 };
  47
  48 /* The version of the API specification.  */
  49
  50 enum ld_plugin_api_version
  51 {
  52   LD_PLUGIN_API_VERSION = 1
  53 };
  54
  55 /* The type of output file being generated by the linker.  */
  56
  57 enum ld_plugin_output_file_type
  58 {
  59   LDPO_REL,
  60   LDPO_EXEC,
  61   LDPO_DYN
  62 };
  63
  64 /* An input file managed by the plugin library.  */
  65
  66 struct ld_plugin_input_file
  67 {
  68   const char *name;
  69   int fd;
  70   off_t offset;
  71   off_t filesize;
  72   void *handle;
  73 };
  74
  75 /* A symbol belonging to an input file managed by the plugin library.  */
  76
  77 struct ld_plugin_symbol
  78 {
  79   char *name;
  80   char *version;
  81   int def;
  82   int visibility;
  83   uint64_t size;
  84   char *comdat_key;
  85   int resolution;
  86 };
  87
  88 /* Whether the symbol is a definition, reference, or common, weak or not.  */
  89
  90 enum ld_plugin_symbol_kind
  91 {
  92   LDPK_DEF,
  93   LDPK_WEAKDEF,
  94   LDPK_UNDEF,
  95   LDPK_WEAKUNDEF,
  96   LDPK_COMMON
  97 };
  98
  99 /* The visibility of the symbol.  */
 100
 101 enum ld_plugin_symbol_visibility
 102 {
 103   LDPV_DEFAULT,
 104   LDPV_PROTECTED,
 105   LDPV_INTERNAL,
 106   LDPV_HIDDEN
 107 };
 108
 109 /* How a symbol is resolved.  */
 110
 111 enum ld_plugin_symbol_resolution
 112 {
 113   LDPR_UNKNOWN = 0,
 114
 115   /* Symbol is still undefined at this point.  */
 116   LDPR_UNDEF,
 117
 118   /* This is the prevailing definition of the symbol, with references from
 119      regular object code.  */
 120   LDPR_PREVAILING_DEF,
 121
 122   /* This is the prevailing definition of the symbol, with no
 123      references from regular objects.  It is only referenced from IR
 124      code.  */
 125   LDPR_PREVAILING_DEF_IRONLY,
 126
 127   /* This definition was pre-empted by a definition in a regular
 128      object file.  */
 129   LDPR_PREEMPTED_REG,
 130
 131   /* This definition was pre-empted by a definition in another IR file.  */
 132   LDPR_PREEMPTED_IR,
 133
 134   /* This symbol was resolved by a definition in another IR file.  */
 135   LDPR_RESOLVED_IR,
 136
 137   /* This symbol was resolved by a definition in a regular object
 138      linked into the main executable.  */
 139   LDPR_RESOLVED_EXEC,
 140
 141   /* This symbol was resolved by a definition in a shared object.  */
 142   LDPR_RESOLVED_DYN
 143 };
 144
 145 /* The plugin library's "claim file" handler.  */
 146
 147 typedef
 148 enum ld_plugin_status
 149 (*ld_plugin_claim_file_handler) (
 150   const struct ld_plugin_input_file *file, int *claimed);
 151
 152 /* The plugin library's "all symbols read" handler.  */
 153
 154 typedef
 155 enum ld_plugin_status
 156 (*ld_plugin_all_symbols_read_handler) (void);
 157
 158 /* The plugin library's cleanup handler.  */
 159
 160 typedef
 161 enum ld_plugin_status
 162 (*ld_plugin_cleanup_handler) (void);
 163
 164 /* The linker's interface for registering the "claim file" handler.  */
 165
 166 typedef
 167 enum ld_plugin_status
 168 (*ld_plugin_register_claim_file) (ld_plugin_claim_file_handler handler);
 169
 170 /* The linker's interface for registering the "all symbols read" handler.  */
 171
 172 typedef
 173 enum ld_plugin_status
 174 (*ld_plugin_register_all_symbols_read) (
 175   ld_plugin_all_symbols_read_handler handler);
 176
 177 /* The linker's interface for registering the cleanup handler.  */
 178
 179 typedef
 180 enum ld_plugin_status
 181 (*ld_plugin_register_cleanup) (ld_plugin_cleanup_handler handler);
 182
 183 /* The linker's interface for adding symbols from a claimed input file.  */
 184
 185 typedef
 186 enum ld_plugin_status
 187 (*ld_plugin_add_symbols) (void *handle, int nsyms,
 188                           const struct ld_plugin_symbol *syms);
 189
 190 /* The linker's interface for getting the input file information with
 191    an open (possibly re-opened) file descriptor.  */
 192
 193 typedef
 194 enum ld_plugin_status
 195 (*ld_plugin_get_input_file) (const void *handle,
 196                              struct ld_plugin_input_file *file);
 197
 198 /* The linker's interface for releasing the input file.  */
 199
 200 typedef
 201 enum ld_plugin_status
 202 (*ld_plugin_release_input_file) (const void *handle);
 203
 204 /* The linker's interface for retrieving symbol resolution information.  */
 205
 206 typedef
 207 enum ld_plugin_status
 208 (*ld_plugin_get_symbols) (const void *handle, int nsyms,
 209                           struct ld_plugin_symbol *syms);
 210
 211 /* The linker's interface for adding a compiled input file.  */
 212
 213 typedef
 214 enum ld_plugin_status
 215 (*ld_plugin_add_input_file) (char *pathname);
 216
 217 /* The linker's interface for adding a library that should be searched.  */
 218
 219 typedef
 220 enum ld_plugin_status
 221 (*ld_plugin_add_input_library) (char *pathname);
 222
 223 /* The linker's interface for issuing a warning or error message.  */
 224
 225 typedef
 226 enum ld_plugin_status
 227 (*ld_plugin_message) (int level, const char *format, ...);
 228
 229 enum ld_plugin_level
 230 {
 231   LDPL_INFO,
 232   LDPL_WARNING,
 233   LDPL_ERROR,
 234   LDPL_FATAL
 235 };
 236
 237 /* Values for the tv_tag field of the transfer vector.  */
 238
 239 enum ld_plugin_tag
 240 {
 241   LDPT_NULL = 0,
 242   LDPT_API_VERSION,
 243   LDPT_GOLD_VERSION,
 244   LDPT_LINKER_OUTPUT,
 245   LDPT_OPTION,
 246   LDPT_REGISTER_CLAIM_FILE_HOOK,
 247   LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK,
 248   LDPT_REGISTER_CLEANUP_HOOK,
 249   LDPT_ADD_SYMBOLS,
 250   LDPT_GET_SYMBOLS,
 251   LDPT_ADD_INPUT_FILE,
 252   LDPT_MESSAGE,
 253   LDPT_GET_INPUT_FILE,
 254   LDPT_RELEASE_INPUT_FILE,
 255   LDPT_ADD_INPUT_LIBRARY
 256 };
 257
 258 /* The plugin transfer vector.  */
 259
 260 struct ld_plugin_tv
 261 {
 262   enum ld_plugin_tag tv_tag;
 263   union
 264   {
 265     int tv_val;
 266     const char *tv_string;
 267     ld_plugin_register_claim_file tv_register_claim_file;
 268     ld_plugin_register_all_symbols_read tv_register_all_symbols_read;
 269     ld_plugin_register_cleanup tv_register_cleanup;
 270     ld_plugin_add_symbols tv_add_symbols;
 271     ld_plugin_get_symbols tv_get_symbols;
 272     ld_plugin_add_input_file tv_add_input_file;
 273     ld_plugin_message tv_message;
 274     ld_plugin_get_input_file tv_get_input_file;
 275     ld_plugin_release_input_file tv_release_input_file;
 276     ld_plugin_add_input_library tv_add_input_library;
 277   } tv_u;
 278 };
 279
 280 /* The plugin library's "onload" entry point.  */
 281
 282 typedef
 283 enum ld_plugin_status
 284 (*ld_plugin_onload) (struct ld_plugin_tv *tv);
 285
 286 #ifdef __cplusplus
 287 }
 288 #endif
 289
 290 #endif /* !defined(PLUGIN_API_H) */