1 /* Support macros for making weak and strong aliases for symbols, 2 and for using symbol sets and linker warnings with GNU ld. 3 Copyright (C) 1995-1998,2000,2001,2002,2003 Free Software Foundation, Inc. 4 This file is part of the GNU C Library. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. */ 20 21 #ifndef _LIBC_SYMBOLS_H 22 #define _LIBC_SYMBOLS_H 1 23 24 /* This file's macros are included implicitly in the compilation of every 25 file in the C library by -imacros. 26 27 We include config.h which is generated by configure. 28 It should define for us the following symbols: 29 30 * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'. 31 * ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'. 32 * ASM_TYPE_DIRECTIVE_PREFIX with `@' or `#' or whatever for .type, 33 or leave it undefined if there is no .type directive. 34 * HAVE_GNU_LD if using GNU ld, with support for weak symbols in a.out, 35 and for symbol set and warning messages extensions in a.out and ELF. 36 * HAVE_ELF if using ELF, which supports weak symbols using `.weak'. 37 * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'. 38 * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'. 39 40 */ 41 42 /* This is defined for the compilation of all C library code. features.h 43 tests this to avoid inclusion of stubs.h while compiling the library, 44 before stubs.h has been generated. Some library code that is shared 45 with other packages also tests this symbol to see if it is being 46 compiled as part of the C library. We must define this before including 47 config.h, because it makes some definitions conditional on whether libc 48 itself is being compiled, or just some generator program. */ 49 #define _LIBC 1 50 51 /* Enable declarations of GNU extensions, since we are compiling them. */ 52 #define _GNU_SOURCE 1 53 /* And we also need the data for the reentrant functions. */ 54 #define _REENTRANT 1 55 56 #include <config.h> 57 58 /* The symbols in all the user (non-_) macros are C symbols. 59 HAVE_GNU_LD without HAVE_ELF implies a.out. */ 60 61 #if defined HAVE_ASM_WEAK_DIRECTIVE || defined HAVE_ASM_WEAKEXT_DIRECTIVE 62 # define HAVE_WEAK_SYMBOLS 63 #endif 64 65 #ifndef __SYMBOL_PREFIX 66 # ifdef NO_UNDERSCORES 67 # define __SYMBOL_PREFIX 68 # else 69 # define __SYMBOL_PREFIX "_" 70 # endif 71 #endif 72 73 #ifndef C_SYMBOL_NAME 74 # ifdef NO_UNDERSCORES 75 # define C_SYMBOL_NAME(name) name 76 # else 77 # define C_SYMBOL_NAME(name) _##name 78 # endif 79 #endif 80 81 #ifndef ASM_LINE_SEP 82 # define ASM_LINE_SEP ; 83 #endif 84 85 #ifdef HAVE_ASM_GLOBAL_DOT_NAME 86 # ifndef C_SYMBOL_DOT_NAME 87 # if defined __GNUC__ && defined __GNUC_MINOR__ \ 88 && (__GNUC__ << 16) + __GNUC_MINOR__ >= (3 << 16) + 1 89 # define C_SYMBOL_DOT_NAME(name) .name 90 # else 91 # define C_SYMBOL_DOT_NAME(name) .##name 92 # endif 93 # endif 94 #endif 95 96 #ifndef __ASSEMBLER__ 97 /* GCC understands weak symbols and aliases; use its interface where 98 possible, instead of embedded assembly language. */ 99 100 /* Define ALIASNAME as a strong alias for NAME. */ 101 # define strong_alias(name, aliasname) _strong_alias(name, aliasname) 102 # define _strong_alias(name, aliasname) \ 103 extern __typeof (name) aliasname __attribute__ ((alias (#name))); 104 105 /* This comes between the return type and function name in 106 a function definition to make that definition weak. */ 107 # define weak_function __attribute__ ((weak)) 108 # define weak_const_function __attribute__ ((weak, __const__)) 109 110 # ifdef HAVE_WEAK_SYMBOLS 111 112 /* Define ALIASNAME as a weak alias for NAME. 113 If weak aliases are not available, this defines a strong alias. */ 114 # define weak_alias(name, aliasname) _weak_alias (name, aliasname) 115 # define _weak_alias(name, aliasname) \ 116 extern __typeof (name) aliasname __attribute__ ((weak, alias (#name))); 117 118 /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined). */ 119 # define weak_extern(symbol) _weak_extern (weak symbol) 120 # define _weak_extern(expr) _Pragma (#expr) 121 122 # else 123 124 # define weak_alias(name, aliasname) strong_alias(name, aliasname) 125 # define weak_extern(symbol) /* Nothing. */ 126 127 # endif 128 129 #else /* __ASSEMBLER__ */ 130 131 # ifdef HAVE_ASM_SET_DIRECTIVE 132 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 133 # define strong_alias(original, alias) \ 134 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 135 .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP \ 136 ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ 137 .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original) 138 # define strong_data_alias(original, alias) \ 139 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 140 .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) 141 # else 142 # define strong_alias(original, alias) \ 143 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 144 .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) 145 # define strong_data_alias(original, alias) strong_alias(original, alias) 146 # endif 147 # else 148 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 149 # define strong_alias(original, alias) \ 150 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 151 C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ 152 ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ 153 C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) 154 # define strong_data_alias(original, alias) \ 155 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 156 C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) 157 # else 158 # define strong_alias(original, alias) \ 159 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 160 C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) 161 # define strong_data_alias(original, alias) strong_alias(original, alias) 162 # endif 163 # endif 164 165 # ifdef HAVE_WEAK_SYMBOLS 166 # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE 167 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 168 # define weak_alias(original, alias) \ 169 .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \ 170 .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) 171 # else 172 # define weak_alias(original, alias) \ 173 .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) 174 # endif 175 # define weak_extern(symbol) \ 176 .weakext C_SYMBOL_NAME (symbol) 177 178 # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ 179 180 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 181 # define weak_alias(original, alias) \ 182 .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 183 C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \ 184 .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ 185 C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) 186 # else 187 # define weak_alias(original, alias) \ 188 .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 189 C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) 190 # endif 191 192 # define weak_extern(symbol) \ 193 .weak C_SYMBOL_NAME (symbol) 194 195 # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ 196 197 # else /* ! HAVE_WEAK_SYMBOLS */ 198 199 # define weak_alias(original, alias) strong_alias(original, alias) 200 # define weak_extern(symbol) /* Nothing */ 201 # endif /* ! HAVE_WEAK_SYMBOLS */ 202 203 #endif /* __ASSEMBLER__ */ 204 205 /* On some platforms we can make internal function calls (i.e., calls of 206 functions not exported) a bit faster by using a different calling 207 convention. */ 208 #ifndef internal_function 209 # define internal_function /* empty */ 210 #endif 211 212 /* Prepare for the case that `__builtin_expect' is not available. */ 213 #ifndef HAVE_BUILTIN_EXPECT 214 # define __builtin_expect(expr, val) (expr) 215 #endif 216 217 /* Determine the return address. */ 218 #define RETURN_ADDRESS(nr) \ 219 __builtin_extract_return_addr (__builtin_return_address (nr)) 220 221 /* When a reference to SYMBOL is encountered, the linker will emit a 222 warning message MSG. */ 223 #ifdef HAVE_GNU_LD 224 # ifdef HAVE_ELF 225 226 /* We want the .gnu.warning.SYMBOL section to be unallocated. */ 227 # ifdef HAVE_ASM_PREVIOUS_DIRECTIVE 228 # define __make_section_unallocated(section_string) \ 229 asm (".section " section_string "\n\t.previous"); 230 # elif defined HAVE_ASM_POPSECTION_DIRECTIVE 231 # define __make_section_unallocated(section_string) \ 232 asm (".pushsection " section_string "\n\t.popsection"); 233 # else 234 # define __make_section_unallocated(section_string) 235 # endif 236 237 /* Tacking on "\n\t#" to the section name makes gcc put it's bogus 238 section attributes on what looks like a comment to the assembler. */ 239 # ifdef HAVE_SECTION_QUOTES 240 # define __sec_comment "\"\n\t#\"" 241 # else 242 # define __sec_comment "\n\t#" 243 # endif 244 # define link_warning(symbol, msg) \ 245 __make_section_unallocated (".gnu.warning." #symbol) \ 246 static const char __evoke_link_warning_##symbol[] \ 247 __attribute__ ((unused, section (".gnu.warning." #symbol __sec_comment))) \ 248 = msg; 249 # define libc_freeres_ptr(decl) \ 250 __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \ 251 decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment))) 252 # define __libc_freeres_fn_section \ 253 __attribute__ ((section ("__libc_freeres_fn"))) 254 # else /* Not ELF: a.out */ 255 # ifdef HAVE_XCOFF 256 /* XCOFF does not support .stabs. 257 The native aix linker will remove the .stab and .stabstr sections 258 The gnu linker will have a fatal error if there is a relocation for 259 symbol in the .stab section. Silently disable this macro. */ 260 # define link_warning(symbol, msg) 261 # else 262 # define link_warning(symbol, msg) \ 263 asm (".stabs \"" msg "\",30,0,0,0\n\t" \ 264 ".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n"); 265 # endif /* XCOFF */ 266 # define libc_freeres_ptr(decl) decl 267 # define __libc_freeres_fn_section 268 # endif 269 #else 270 /* We will never be heard; they will all die horribly. */ 271 # define link_warning(symbol, msg) 272 # define libc_freeres_ptr(decl) decl 273 # define __libc_freeres_fn_section 274 #endif 275 #define libc_freeres_fn(name) \ 276 static void name (void) __attribute_used__ __libc_freeres_fn_section; \ 277 text_set_element (__libc_subfreeres, name); \ 278 static void name (void) 279 280 /* A canned warning for sysdeps/stub functions. */ 281 #define stub_warning(name) \ 282 link_warning (name, \ 283 "warning: " #name " is not implemented and will always fail") 284 285 286 /* Declare SYMBOL to be TYPE (`function' or `object') and of SIZE bytes, 287 when the assembler supports such declarations (such as in ELF). 288 This is only necessary when defining something in assembly, or playing 289 funny alias games where the size should be other than what the compiler 290 thinks it is. */ 291 #define declare_symbol(symbol, type, size) \ 292 declare_symbol_1 (symbol, type, size) 293 #ifdef ASM_TYPE_DIRECTIVE_PREFIX 294 # ifdef __ASSEMBLER__ 295 # define declare_symbol_1(symbol, type, size) \ 296 .type C_SYMBOL_NAME (symbol), \ 297 declare_symbol_1_paste (ASM_TYPE_DIRECTIVE_PREFIX, type), size 298 # define declare_symbol_1_paste(a, b) declare_symbol_1_paste_1 (a,b) 299 # define declare_symbol_1_paste_1(a,b) a##b 300 # else /* Not __ASSEMBLER__. */ 301 # define declare_symbol_1(symbol, type, size) \ 302 asm (".type " __SYMBOL_PREFIX #symbol ", " \ 303 declare_symbol_1_stringify (ASM_TYPE_DIRECTIVE_PREFIX) #type \ 304 "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size); 305 # define declare_symbol_1_stringify(x) declare_symbol_1_stringify_1 (x) 306 # define declare_symbol_1_stringify_1(x) #x 307 # endif /* __ASSEMBLER__ */ 308 #else 309 # define declare_symbol_1(symbol, type, size) /* Nothing. */ 310 #endif 311 312 313 /* 314 315 */ 316 317 #ifdef HAVE_GNU_LD 318 319 /* Symbol set support macros. */ 320 321 # ifdef HAVE_ELF 322 323 /* Make SYMBOL, which is in the text segment, an element of SET. */ 324 # define text_set_element(set, symbol) _elf_set_element(set, symbol) 325 /* Make SYMBOL, which is in the data segment, an element of SET. */ 326 # define data_set_element(set, symbol) _elf_set_element(set, symbol) 327 /* Make SYMBOL, which is in the bss segment, an element of SET. */ 328 # define bss_set_element(set, symbol) _elf_set_element(set, symbol) 329 330 /* These are all done the same way in ELF. 331 There is a new section created for each set. */ 332 # ifdef SHARED 333 /* When building a shared library, make the set section writable, 334 because it will need to be relocated at run time anyway. */ 335 # define _elf_set_element(set, symbol) \ 336 static const void *__elf_set_##set##_element_##symbol##__ \ 337 __attribute__ ((unused, section (#set))) = &(symbol) 338 # else 339 # define _elf_set_element(set, symbol) \ 340 static const void *const __elf_set_##set##_element_##symbol##__ \ 341 __attribute__ ((unused, section (#set))) = &(symbol) 342 # endif 343 344 /* Define SET as a symbol set. This may be required (it is in a.out) to 345 be able to use the set's contents. */ 346 # define symbol_set_define(set) symbol_set_declare(set) 347 348 /* Declare SET for use in this module, if defined in another module. */ 349 # define symbol_set_declare(set) \ 350 extern void *const __start_##set __attribute__ ((__weak__)); \ 351 extern void *const __stop_##set __attribute__ ((__weak__)); \ 352 weak_extern (__start_##set) weak_extern (__stop_##set) 353 354 /* Return a pointer (void *const *) to the first element of SET. */ 355 # define symbol_set_first_element(set) (&__start_##set) 356 357 /* Return true iff PTR (a void *const *) has been incremented 358 past the last element in SET. */ 359 # define symbol_set_end_p(set, ptr) ((ptr) >= &__stop_##set) 360 361 # else /* Not ELF: a.out. */ 362 363 # ifdef HAVE_XCOFF 364 /* XCOFF does not support .stabs. 365 The native aix linker will remove the .stab and .stabstr sections 366 The gnu linker will have a fatal error if there is a relocation for 367 symbol in the .stab section. Silently disable these macros. */ 368 # define text_set_element(set, symbol) 369 # define data_set_element(set, symbol) 370 # define bss_set_element(set, symbol) 371 # else 372 # define text_set_element(set, symbol) \ 373 asm (".stabs \"" __SYMBOL_PREFIX #set "\",23,0,0," __SYMBOL_PREFIX #symbol) 374 # define data_set_element(set, symbol) \ 375 asm (".stabs \"" __SYMBOL_PREFIX #set "\",25,0,0," __SYMBOL_PREFIX #symbol) 376 # define bss_set_element(set, symbol) ?error Must use initialized data. 377 # endif /* XCOFF */ 378 # define symbol_set_define(set) void *const (set)[1]; 379 # define symbol_set_declare(set) extern void *const (set)[1]; 380 381 # define symbol_set_first_element(set) &(set)[1] 382 # define symbol_set_end_p(set, ptr) (*(ptr) == 0) 383 384 # endif /* ELF. */ 385 #else 386 /* We cannot do anything in generial. */ 387 # define text_set_element(set, symbol) asm ("") 388 # define data_set_element(set, symbol) asm ("") 389 # define bss_set_element(set, symbol) asm ("") 390 # define symbol_set_define(set) void *const (set)[1]; 391 # define symbol_set_declare(set) extern void *const (set)[1]; 392 393 # define symbol_set_first_element(set) &(set)[1] 394 # define symbol_set_end_p(set, ptr) (*(ptr) == 0) 395 #endif /* Have GNU ld. */ 396 397 #if DO_VERSIONING 398 # define symbol_version(real, name, version) \ 399 _symbol_version(real, name, version) 400 # define default_symbol_version(real, name, version) \ 401 _default_symbol_version(real, name, version) 402 # ifdef __ASSEMBLER__ 403 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 404 # define _symbol_version(real, name, version) \ 405 .symver real, name##@##version ASM_LINE_SEP \ 406 .symver .##real, .##name##@##version 407 # define _default_symbol_version(real, name, version) \ 408 .symver real, name##@##@##version ASM_LINE_SEP \ 409 .symver .##real, .##name##@##@##version 410 # else 411 # define _symbol_version(real, name, version) \ 412 .symver real, name##@##version 413 # define _default_symbol_version(real, name, version) \ 414 .symver real, name##@##@##version 415 # endif 416 # else 417 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 418 # define _symbol_version(real, name, version) \ 419 __asm__ (".symver " #real "," #name "@" #version "\n\t" \ 420 ".symver ." #real ",." #name "@" #version) 421 # define _default_symbol_version(real, name, version) \ 422 __asm__ (".symver " #real "," #name "@@" #version "\n\t" \ 423 ".symver ." #real ",." #name "@@" #version) 424 # else 425 # define _symbol_version(real, name, version) \ 426 __asm__ (".symver " #real "," #name "@" #version) 427 # define _default_symbol_version(real, name, version) \ 428 __asm__ (".symver " #real "," #name "@@" #version) 429 # endif 430 # endif 431 #else 432 # define symbol_version(real, name, version) 433 # define default_symbol_version(real, name, version) \ 434 strong_alias(real, name) 435 #endif 436 437 #if defined HAVE_VISIBILITY_ATTRIBUTE && defined SHARED 438 # define attribute_hidden __attribute__ ((visibility ("hidden"))) 439 #else 440 # define attribute_hidden 441 #endif 442 443 #if defined HAVE_TLS_MODEL_ATTRIBUTE 444 # define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec"))) 445 #else 446 # define attribute_tls_model_ie 447 #endif 448 449 /* Handling on non-exported internal names. We have to do this only 450 for shared code. */ 451 #ifdef SHARED 452 # define INTUSE(name) name##_internal 453 # define INTDEF(name) strong_alias (name, name##_internal) 454 # define INTVARDEF(name) \ 455 _INTVARDEF (name, name##_internal) 456 # if defined HAVE_VISIBILITY_ATTRIBUTE 457 # define _INTVARDEF(name, aliasname) \ 458 extern __typeof (name) aliasname __attribute__ ((alias (#name), \ 459 visibility ("hidden"))); 460 # else 461 # define _INTVARDEF(name, aliasname) \ 462 extern __typeof (name) aliasname __attribute__ ((alias (#name))); 463 # endif 464 # define INTDEF2(name, newname) strong_alias (name, newname##_internal) 465 # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal) 466 #else 467 # define INTUSE(name) name 468 # define INTDEF(name) 469 # define INTVARDEF(name) 470 # define INTDEF2(name, newname) 471 # define INTVARDEF2(name, newname) 472 #endif 473 474 /* The following macros are used for PLT bypassing within libc.so 475 (and if needed other libraries similarly). 476 First of all, you need to have the function prototyped somewhere, 477 say in foo/foo.h: 478 479 int foo (int __bar); 480 481 If calls to foo within libc.so should always go to foo defined in libc.so, 482 then in include/foo.h you add: 483 484 libc_hidden_proto (foo) 485 486 line and after the foo function definition: 487 488 int foo (int __bar) 489 { 490 return __bar; 491 } 492 libc_hidden_def (foo) 493 494 or 495 496 int foo (int __bar) 497 { 498 return __bar; 499 } 500 libc_hidden_weak (foo) 501 502 Simularly for global data. If references to foo within libc.so should 503 always go to foo defined in libc.so, then in include/foo.h you add: 504 505 libc_hidden_proto (foo) 506 507 line and after foo's definition: 508 509 int foo = INITIAL_FOO_VALUE; 510 libc_hidden_data_def (foo) 511 512 or 513 514 int foo = INITIAL_FOO_VALUE; 515 libc_hidden_data_weak (foo) 516 517 If foo is normally just an alias (strong or weak) of some other function, 518 you should use the normal strong_alias first, then add libc_hidden_def 519 or libc_hidden_weak: 520 521 int baz (int __bar) 522 { 523 return __bar; 524 } 525 strong_alias (baz, foo) 526 libc_hidden_weak (foo) 527 528 If the function should be internal to multiple objects, say ld.so and 529 libc.so, the best way is to use: 530 531 #if !defined NOT_IN_libc || defined IS_IN_rtld 532 hidden_proto (foo) 533 #endif 534 535 in include/foo.h and the normal macros at all function definitions 536 depending on what DSO they belong to. 537 538 If versioned_symbol macro is used to define foo, 539 libc_hidden_ver macro should be used, as in: 540 541 int __real_foo (int __bar) 542 { 543 return __bar; 544 } 545 versioned_symbol (libc, __real_foo, foo, GLIBC_2_1); 546 libc_hidden_ver (__real_foo, foo) */ 547 548 #if defined SHARED && defined DO_VERSIONING \ 549 && !defined HAVE_BROKEN_ALIAS_ATTRIBUTE && !defined NO_HIDDEN 550 # ifndef __ASSEMBLER__ 551 # if !defined HAVE_VISIBILITY_ATTRIBUTE \ 552 || defined HAVE_BROKEN_VISIBILITY_ATTRIBUTE 553 # define __hidden_proto_hiddenattr(attrs...) 554 # else 555 # define __hidden_proto_hiddenattr(attrs...) \ 556 __attribute__ ((visibility ("hidden"), ##attrs)) 557 # endif 558 # define hidden_proto(name, attrs...) \ 559 __hidden_proto (name, __GI_##name, ##attrs) 560 # define __hidden_proto(name, internal, attrs...) \ 561 extern __typeof (name) internal; \ 562 extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \ 563 __hidden_proto_hiddenattr (attrs); 564 # define __hidden_asmname(name) \ 565 __hidden_asmname1 (__USER_LABEL_PREFIX__, name) 566 # define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name) 567 # define __hidden_asmname2(prefix, name) #prefix name 568 # ifdef HAVE_ASM_SET_DIRECTIVE 569 # define __hidden_def1(original, alias) \ 570 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 571 .set C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) 572 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 573 # define __hidden_dot_def1(original, alias) ASM_LINE_SEP \ 574 ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ 575 .set C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) 576 # else 577 # define __hidden_dot_def1(original, alias) 578 # endif 579 # else 580 # define __hidden_def1(original, alias) \ 581 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 582 C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) 583 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 584 # define __hidden_dot_def1(original, alias) ASM_LINE_SEP \ 585 ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ 586 C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) 587 # else 588 # define __hidden_dot_def1(original, alias) 589 # endif 590 # endif 591 # define __hidden_def2(...) #__VA_ARGS__ 592 # define __hidden_def3(...) __hidden_def2 (__VA_ARGS__) 593 # define hidden_def(name) \ 594 __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name) \ 595 __hidden_dot_def1 (__GI_##name, name))); 596 # define hidden_data_def(name) \ 597 __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name))); 598 # define hidden_ver(local, name) \ 599 __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name) \ 600 __hidden_dot_def1 (local, __GI_##name))); 601 # define hidden_data_ver(local, name) \ 602 __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name))); 603 # ifdef HAVE_WEAK_SYMBOLS 604 # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE 605 # define __hidden_weak1(original, alias) \ 606 .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) 607 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 608 # define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \ 609 .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original) 610 # else 611 # define __hidden_dot_weak1(original, alias) 612 # endif 613 # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ 614 # define __hidden_weak1(original, alias) \ 615 .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \ 616 C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) 617 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 618 # define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \ 619 .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \ 620 C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original) 621 # else 622 # define __hidden_dot_weak1(original, alias) 623 # endif 624 # endif 625 # define hidden_weak(name) \ 626 __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name) \ 627 __hidden_dot_weak1 (__GI_##name, name))); 628 # define hidden_data_weak(name) \ 629 __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name))); 630 # else 631 # define hidden_weak(name) hidden_def (name) 632 # endif 633 # else 634 /* For assembly, we need to do the opposite of what we do in C: 635 in assembly gcc __REDIRECT stuff is not in place, so functions 636 are defined by its normal name and we need to create the 637 __GI_* alias to it, in C __REDIRECT causes the function definition 638 to use __GI_* name and we need to add alias to the real name. 639 There is no reason to use hidden_weak over hidden_def in assembly, 640 but we provide it for consistency with the C usage. 641 hidden_proto doesn't make sense for assembly but the equivalent 642 is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET. */ 643 # define hidden_def(name) strong_alias (name, __GI_##name) 644 # define hidden_weak(name) hidden_def (name) 645 # define hidden_ver(local, name) strong_alias (local, __GI_##name) 646 # define hidden_data_def(name) strong_data_alias (name, __GI_##name) 647 # define hidden_data_weak(name) hidden_data_def (name) 648 # define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name) 649 # ifdef HAVE_ASM_GLOBAL_DOT_NAME 650 # define HIDDEN_JUMPTARGET(name) .__GI_##name 651 # else 652 # define HIDDEN_JUMPTARGET(name) __GI_##name 653 # endif 654 # endif 655 #else 656 # ifndef __ASSEMBLER__ 657 # define hidden_proto(name, attrs...) 658 # else 659 # define HIDDEN_JUMPTARGET(name) JUMPTARGET(name) 660 # endif /* Not __ASSEMBLER__ */ 661 # define hidden_weak(name) 662 # define hidden_def(name) 663 # define hidden_ver(local, name) 664 # define hidden_data_weak(name) 665 # define hidden_data_def(name) 666 # define hidden_data_ver(local, name) 667 #endif 668 669 #if !defined NOT_IN_libc 670 # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) 671 # define libc_hidden_def(name) hidden_def (name) 672 # define libc_hidden_weak(name) hidden_weak (name) 673 # define libc_hidden_ver(local, name) hidden_ver (local, name) 674 # define libc_hidden_data_def(name) hidden_data_def (name) 675 # define libc_hidden_data_weak(name) hidden_data_weak (name) 676 # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name) 677 #else 678 # define libc_hidden_proto(name, attrs...) 679 # define libc_hidden_def(name) 680 # define libc_hidden_weak(name) 681 # define libc_hidden_ver(local, name) 682 # define libc_hidden_data_def(name) 683 # define libc_hidden_data_weak(name) 684 # define libc_hidden_data_ver(local, name) 685 #endif 686 687 #if defined NOT_IN_libc && defined IS_IN_rtld 688 # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) 689 # define rtld_hidden_def(name) hidden_def (name) 690 # define rtld_hidden_weak(name) hidden_weak (name) 691 # define rtld_hidden_ver(local, name) hidden_ver (local, name) 692 # define rtld_hidden_data_def(name) hidden_data_def (name) 693 # define rtld_hidden_data_weak(name) hidden_data_weak (name) 694 # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name) 695 #else 696 # define rtld_hidden_proto(name, attrs...) 697 # define rtld_hidden_def(name) 698 # define rtld_hidden_weak(name) 699 # define rtld_hidden_ver(local, name) 700 # define rtld_hidden_data_def(name) 701 # define rtld_hidden_data_weak(name) 702 # define rtld_hidden_data_ver(local, name) 703 #endif 704 705 #if defined NOT_IN_libc && defined IS_IN_libm 706 # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) 707 # define libm_hidden_def(name) hidden_def (name) 708 # define libm_hidden_weak(name) hidden_weak (name) 709 # define libm_hidden_ver(local, name) hidden_ver (local, name) 710 # define libm_hidden_data_def(name) hidden_data_def (name) 711 # define libm_hidden_data_weak(name) hidden_data_weak (name) 712 # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name) 713 #else 714 # define libm_hidden_proto(name, attrs...) 715 # define libm_hidden_def(name) 716 # define libm_hidden_weak(name) 717 # define libm_hidden_ver(local, name) 718 # define libm_hidden_data_def(name) 719 # define libm_hidden_data_weak(name) 720 # define libm_hidden_data_ver(local, name) 721 #endif 722 723 #endif /* libc-symbols.h */ 724