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