include/libc-symbols.h

   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) 1995-1998,2000-2003,2004,2005,2006
   4         Free Software Foundation, Inc.
   5    This file is part of the GNU C Library.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, write to the Free
  19    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20    02111-1307 USA.  */
  21
  22 #ifndef _LIBC_SYMBOLS_H
  23 #define _LIBC_SYMBOLS_H 1
  24
  25 /* This file's macros are included implicitly in the compilation of every
  26    file in the C library by -imacros.
  27
  28    We include config.h which is generated by configure.
  29    It should define for us the following symbols:
  30
  31    * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'.
  32    * ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'.
  33    * ASM_TYPE_DIRECTIVE_PREFIX with `@' or `#' or whatever for .type,
  34      or leave it undefined if there is no .type directive.
  35    * HAVE_ELF if using ELF, which supports weak symbols using `.weak'.
  36    * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'.
  37    * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'.
  38
  39    */
  40
  41 /* This is defined for the compilation of all C library code.  features.h
  42    tests this to avoid inclusion of stubs.h while compiling the library,
  43    before stubs.h has been generated.  Some library code that is shared
  44    with other packages also tests this symbol to see if it is being
  45    compiled as part of the C library.  We must define this before including
  46    config.h, because it makes some definitions conditional on whether libc
  47    itself is being compiled, or just some generator program.  */
  48 #define _LIBC   1
  49
  50 /* Enable declarations of GNU extensions, since we are compiling them.  */
  51 #define _GNU_SOURCE     1
  52 /* And we also need the data for the reentrant functions.  */
  53 #define _REENTRANT      1
  54
  55 #include <config.h>
  56
  57 /* The symbols in all the user (non-_) macros are C symbols.
  58    NO HAVE_ELF implies a.out.  */
  59
  60 #if defined HAVE_ASM_WEAK_DIRECTIVE || defined HAVE_ASM_WEAKEXT_DIRECTIVE
  61 # define HAVE_WEAK_SYMBOLS
  62 #endif
  63
  64 #ifndef __SYMBOL_PREFIX
  65 # ifdef NO_UNDERSCORES
  66 #  define __SYMBOL_PREFIX
  67 # else
  68 #  define __SYMBOL_PREFIX "_"
  69 # endif
  70 #endif
  71
  72 #ifndef C_SYMBOL_NAME
  73 # ifdef NO_UNDERSCORES
  74 #  define C_SYMBOL_NAME(name) name
  75 # else
  76 #  define C_SYMBOL_NAME(name) _##name
  77 # endif
  78 #endif
  79
  80 #ifndef ASM_LINE_SEP
  81 # define ASM_LINE_SEP ;
  82 #endif
  83
  84 #ifdef HAVE_ASM_GLOBAL_DOT_NAME
  85 # ifndef C_SYMBOL_DOT_NAME
  86 #  if defined __GNUC__ && defined __GNUC_MINOR__ \
  87       && (__GNUC__ << 16) + __GNUC_MINOR__ >= (3 << 16) + 1
  88 #   define C_SYMBOL_DOT_NAME(name) .name
  89 #  else
  90 #   define C_SYMBOL_DOT_NAME(name) .##name
  91 #  endif
  92 # endif
  93 #endif
  94
  95 #ifndef __ASSEMBLER__
  96 /* GCC understands weak symbols and aliases; use its interface where
  97    possible, instead of embedded assembly language.  */
  98
  99 /* Define ALIASNAME as a strong alias for NAME.  */
 100 # define strong_alias(name, aliasname) _strong_alias(name, aliasname)
 101 # define _strong_alias(name, aliasname) \
 102   extern __typeof (name) aliasname __attribute__ ((alias (#name)));
 103
 104 /* This comes between the return type and function name in
 105    a function definition to make that definition weak.  */
 106 # define weak_function __attribute__ ((weak))
 107 # define weak_const_function __attribute__ ((weak, __const__))
 108
 109 # ifdef HAVE_WEAK_SYMBOLS
 110
 111 /* Define ALIASNAME as a weak alias for NAME.
 112    If weak aliases are not available, this defines a strong alias.  */
 113 #  define weak_alias(name, aliasname) _weak_alias (name, aliasname)
 114 #  define _weak_alias(name, aliasname) \
 115   extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
 116
 117 /* Same as WEAK_ALIAS, but mark symbol as hidden.  */
 118 #  define weak_hidden_alias(name, aliasname) \
 119   _weak_hidden_alias (name, aliasname)
 120 #  define _weak_hidden_alias(name, aliasname) \
 121   extern __typeof (name) aliasname \
 122     __attribute__ ((weak, alias (#name), __visibility__ ("hidden")));
 123
 124 /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined).  */
 125 #  define weak_extern(symbol) _weak_extern (weak symbol)
 126 #  define _weak_extern(expr) _Pragma (#expr)
 127
 128 # else
 129
 130 #  define weak_alias(name, aliasname) strong_alias(name, aliasname)
 131 #  define weak_hidden_alias(name, aliasname) strong_alias(name, aliasname)
 132 #  define weak_extern(symbol) /* Nothing. */
 133
 134 # endif
 135
 136 #else /* __ASSEMBLER__ */
 137
 138 # ifdef HAVE_ASM_SET_DIRECTIVE
 139 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 140 #   define strong_alias(original, alias)                                \
 141   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 142   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP      \
 143   ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP           \
 144   .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original)
 145 #   define strong_data_alias(original, alias)                           \
 146   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 147   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 148 #  else
 149 #   define strong_alias(original, alias)                                \
 150   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 151   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 152 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 153 #  endif
 154 # else
 155 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 156 #   define strong_alias(original, alias)                                \
 157   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 158   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 159   ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP           \
 160   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 161 #   define strong_data_alias(original, alias)                           \
 162   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 163   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 164 #  else
 165 #   define strong_alias(original, alias)                                \
 166   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 167   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 168 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 169 #  endif
 170 # endif
 171
 172 # ifdef HAVE_WEAK_SYMBOLS
 173 #  ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
 174 #   ifdef HAVE_ASM_GLOBAL_DOT_NAME
 175 #    define weak_alias(original, alias)                                 \
 176   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \
 177   .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
 178 #   else
 179 #    define weak_alias(original, alias)                                 \
 180   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
 181 #   endif
 182 #   define weak_extern(symbol)                                          \
 183   .weakext C_SYMBOL_NAME (symbol)
 184
 185 #  else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 186
 187 #   ifdef HAVE_ASM_GLOBAL_DOT_NAME
 188 #    define weak_alias(original, alias)                                 \
 189   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 190   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 191   .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP                          \
 192   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 193 #   else
 194 #    define weak_alias(original, alias)                                 \
 195   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 196   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 197 #   endif
 198
 199 #   define weak_extern(symbol)                                          \
 200   .weak C_SYMBOL_NAME (symbol)
 201
 202 #  endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 203
 204 # else /* ! HAVE_WEAK_SYMBOLS */
 205
 206 #  define weak_alias(original, alias) strong_alias(original, alias)
 207 #  define weak_extern(symbol) /* Nothing */
 208 # endif /* ! HAVE_WEAK_SYMBOLS */
 209
 210 #endif /* __ASSEMBLER__ */
 211
 212 /* On some platforms we can make internal function calls (i.e., calls of
 213    functions not exported) a bit faster by using a different calling
 214    convention.  */
 215 #ifndef internal_function
 216 # define internal_function      /* empty */
 217 #endif
 218
 219 /* Prepare for the case that `__builtin_expect' is not available.  */
 220 #ifndef HAVE_BUILTIN_EXPECT
 221 # define __builtin_expect(expr, val) (expr)
 222 #endif
 223
 224 /* Determine the return address.  */
 225 #define RETURN_ADDRESS(nr) \
 226   __builtin_extract_return_addr (__builtin_return_address (nr))
 227
 228 /* When a reference to SYMBOL is encountered, the linker will emit a
 229    warning message MSG.  */
 230 #ifdef HAVE_ELF
 231
 232 /* We want the .gnu.warning.SYMBOL section to be unallocated.  */
 233 # ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
 234 #  define __make_section_unallocated(section_string)    \
 235   asm (".section " section_string "\n\t.previous");
 236 # elif defined HAVE_ASM_POPSECTION_DIRECTIVE
 237 #  define __make_section_unallocated(section_string)    \
 238   asm (".pushsection " section_string "\n\t.popsection");
 239 # else
 240 #  define __make_section_unallocated(section_string)
 241 # endif
 242
 243 /* Tacking on "\n\t#" to the section name makes gcc put it's bogus
 244    section attributes on what looks like a comment to the assembler.  */
 245 # ifdef HAVE_SECTION_QUOTES
 246 #  define __sec_comment "\"\n\t#\""
 247 # else
 248 #  define __sec_comment "\n\t#"
 249 # endif
 250 # define link_warning(symbol, msg) \
 251   __make_section_unallocated (".gnu.warning." #symbol) \
 252   static const char __evoke_link_warning_##symbol[]     \
 253     __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
 254     = msg;
 255 # define libc_freeres_ptr(decl) \
 256   __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
 257   decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
 258 # define __libc_freeres_fn_section \
 259   __attribute__ ((section ("__libc_freeres_fn")))
 260 #else /* Not ELF: a.out */
 261 # ifdef HAVE_XCOFF
 262 /* XCOFF does not support .stabs.
 263    The native aix linker will remove the .stab and .stabstr sections
 264    The gnu linker will have a fatal error if there is a relocation for
 265    symbol in the .stab section.  Silently disable this macro.  */
 266 #  define link_warning(symbol, msg)
 267 # else
 268 #  define link_warning(symbol, msg)             \
 269      asm (".stabs \"" msg "\",30,0,0,0\n\t"     \
 270           ".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n");
 271 # endif /* XCOFF */
 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   __make_section_unallocated (".gnu.glibc-stub." #name) \
 283   link_warning (name, \
 284                 "warning: " #name " is not implemented and will always fail")
 285
 286 /* Warning for linking functions calling dlopen into static binaries.  */
 287 #ifdef SHARED
 288 #define static_link_warning(name)
 289 #else
 290 #define static_link_warning(name) static_link_warning1(name)
 291 #define static_link_warning1(name) \
 292   link_warning(name, "Using '" #name "' in statically linked applications \
 293 requires at runtime the shared libraries from the glibc version used \
 294 for linking")
 295 #endif
 296
 297 /* Declare SYMBOL to be TYPE (`function' or `object') of SIZE bytes
 298    alias to ORIGINAL, when the assembler supports such declarations
 299    (such as in ELF).
 300    This is only necessary when defining something in assembly, or playing
 301    funny alias games where the size should be other than what the compiler
 302    thinks it is.  */
 303 #define declare_symbol_alias(symbol, original, type, size) \
 304   declare_symbol_alias_1 (symbol, original, type, size)
 305 #ifdef ASM_TYPE_DIRECTIVE_PREFIX
 306 # ifdef __ASSEMBLER__
 307 #  define declare_symbol_alias_1(symbol, original, type, size) \
 308     strong_alias (original, symbol); \
 309     .type C_SYMBOL_NAME (symbol), \
 310           declare_symbol_alias_1_paste (ASM_TYPE_DIRECTIVE_PREFIX, type); \
 311     .size C_SYMBOL_NAME (symbol), size
 312 #  define declare_symbol_alias_1_paste(a, b) \
 313   declare_symbol_alias_1_paste_1 (a,b)
 314 #  define declare_symbol_alias_1_paste_1(a,b)   a##b
 315 # else /* Not __ASSEMBLER__.  */
 316 #  define declare_symbol_alias_1(symbol, original, type, size) \
 317     asm (declare_symbol_alias_1_stringify (ASM_GLOBAL_DIRECTIVE) \
 318          " " __SYMBOL_PREFIX #symbol \
 319          "\n\t" declare_symbol_alias_1_alias (symbol, original) \
 320          "\n\t.type " __SYMBOL_PREFIX #symbol ", " \
 321          declare_symbol_alias_1_stringify (ASM_TYPE_DIRECTIVE_PREFIX) #type \
 322          "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size);
 323 #  define declare_symbol_alias_1_stringify(x) \
 324   declare_symbol_alias_1_stringify_1 (x)
 325 #  define declare_symbol_alias_1_stringify_1(x) #x
 326 #  ifdef HAVE_ASM_SET_DIRECTIVE
 327 #   define declare_symbol_alias_1_alias(symbol, original) \
 328          ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX #original
 329 #  else
 330 #   define declare_symbol_alias_1_alias(symbol, original) \
 331          __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX #original
 332 #  endif /* HAVE_ASM_SET_DIRECTIVE */
 333 # endif /* __ASSEMBLER__ */
 334 #else
 335 # define declare_symbol_1(symbol, type, size) /* Nothing.  */
 336 #endif
 337
 338
 339 /*
 340 \f
 341 */
 342
 343 /* Symbol set support macros.  */
 344
 345 #ifdef HAVE_ELF
 346
 347 /* Make SYMBOL, which is in the text segment, an element of SET.  */
 348 # define text_set_element(set, symbol)  _elf_set_element(set, symbol)
 349 /* Make SYMBOL, which is in the data segment, an element of SET.  */
 350 # define data_set_element(set, symbol)  _elf_set_element(set, symbol)
 351 /* Make SYMBOL, which is in the bss segment, an element of SET.  */
 352 # define bss_set_element(set, symbol)   _elf_set_element(set, symbol)
 353
 354 /* These are all done the same way in ELF.
 355    There is a new section created for each set.  */
 356 # ifdef SHARED
 357 /* When building a shared library, make the set section writable,
 358    because it will need to be relocated at run time anyway.  */
 359 #  define _elf_set_element(set, symbol) \
 360   static const void *__elf_set_##set##_element_##symbol##__ \
 361     __attribute__ ((used, section (#set))) = &(symbol)
 362 # else
 363 #  define _elf_set_element(set, symbol) \
 364   static const void *const __elf_set_##set##_element_##symbol##__ \
 365     __attribute__ ((used, section (#set))) = &(symbol)
 366 # endif
 367
 368 /* Define SET as a symbol set.  This may be required (it is in a.out) to
 369    be able to use the set's contents.  */
 370 # define symbol_set_define(set) symbol_set_declare(set)
 371
 372 /* Declare SET for use in this module, if defined in another module.
 373    In a shared library, this is always local to that shared object.
 374    For static linking, the set might be wholly absent and so we use
 375    weak references.  */
 376 # define symbol_set_declare(set) \
 377   extern char const __start_##set[] __symbol_set_attribute; \
 378   extern char const __stop_##set[] __symbol_set_attribute;
 379 # ifdef SHARED
 380 #  define __symbol_set_attribute attribute_hidden
 381 # else
 382 #  define __symbol_set_attribute __attribute__ ((weak))
 383 # endif
 384
 385 /* Return a pointer (void *const *) to the first element of SET.  */
 386 # define symbol_set_first_element(set)  ((void *const *) (&__start_##set))
 387
 388 /* Return true iff PTR (a void *const *) has been incremented
 389    past the last element in SET.  */
 390 # define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
 391
 392 #else   /* Not ELF: a.out.  */
 393
 394 # ifdef HAVE_XCOFF
 395 /* XCOFF does not support .stabs.
 396    The native aix linker will remove the .stab and .stabstr sections
 397    The gnu linker will have a fatal error if there is a relocation for
 398    symbol in the .stab section.  Silently disable these macros.  */
 399 #  define text_set_element(set, symbol)
 400 #  define data_set_element(set, symbol)
 401 #  define bss_set_element(set, symbol)
 402 # else
 403 #  define text_set_element(set, symbol) \
 404     asm (".stabs \"" __SYMBOL_PREFIX #set "\",23,0,0," __SYMBOL_PREFIX #symbol)
 405 #  define data_set_element(set, symbol) \
 406     asm (".stabs \"" __SYMBOL_PREFIX #set "\",25,0,0," __SYMBOL_PREFIX #symbol)
 407 #  define bss_set_element(set, symbol)  ?error Must use initialized data.
 408 # endif /* XCOFF */
 409 # define symbol_set_define(set) void *const (set)[1];
 410 # define symbol_set_declare(set)        extern void *const (set)[1];
 411
 412 # define symbol_set_first_element(set)  &(set)[1]
 413 # define symbol_set_end_p(set, ptr)     (*(ptr) == 0)
 414
 415 #endif  /* ELF.  */
 416
 417 #if DO_VERSIONING
 418 # define symbol_version(real, name, version) \
 419      _symbol_version(real, name, version)
 420 # define default_symbol_version(real, name, version) \
 421      _default_symbol_version(real, name, version)
 422 # ifdef __ASSEMBLER__
 423 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 424 #   define _symbol_version(real, name, version) \
 425      .symver real, name##@##version ASM_LINE_SEP                        \
 426      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##version)
 427 #   define _default_symbol_version(real, name, version) \
 428      .symver real, name##@##@##version ASM_LINE_SEP                     \
 429      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##@##version)
 430 #  else
 431 #   define _symbol_version(real, name, version) \
 432      .symver real, name##@##version
 433 #   define _default_symbol_version(real, name, version) \
 434      .symver real, name##@##@##version
 435 #  endif
 436 # else
 437 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 438 #   define _symbol_version(real, name, version) \
 439      __asm__ (".symver " #real "," #name "@" #version "\n\t"    \
 440               ".symver ." #real ",." #name "@" #version)
 441 #   define _default_symbol_version(real, name, version) \
 442      __asm__ (".symver " #real "," #name "@@" #version "\n\t"   \
 443               ".symver ." #real ",." #name "@@" #version)
 444 #  else
 445 #   define _symbol_version(real, name, version) \
 446      __asm__ (".symver " #real "," #name "@" #version)
 447 #   define _default_symbol_version(real, name, version) \
 448      __asm__ (".symver " #real "," #name "@@" #version)
 449 #  endif
 450 # endif
 451 #else
 452 # define symbol_version(real, name, version)
 453 # define default_symbol_version(real, name, version) \
 454   strong_alias(real, name)
 455 #endif
 456
 457 #if defined SHARED || defined LIBC_NONSHARED
 458 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 459 #else
 460 # define attribute_hidden
 461 #endif
 462
 463 #ifdef HAVE_TLS_MODEL_ATTRIBUTE
 464 # define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
 465 #else
 466 # define attribute_tls_model_ie
 467 #endif
 468
 469 #define attribute_relro __attribute__ ((section (".data.rel.ro")))
 470
 471 /* Handling on non-exported internal names.  We have to do this only
 472    for shared code.  */
 473 #ifdef SHARED
 474 # define INTUSE(name) name##_internal
 475 # define INTDEF(name) strong_alias (name, name##_internal)
 476 # define INTVARDEF(name) \
 477   _INTVARDEF (name, name##_internal)
 478 # define _INTVARDEF(name, aliasname) \
 479   extern __typeof (name) aliasname __attribute__ ((alias (#name), \
 480                                                    visibility ("hidden")));
 481 # define INTDEF2(name, newname) strong_alias (name, newname##_internal)
 482 # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal)
 483 #else
 484 # define INTUSE(name) name
 485 # define INTDEF(name)
 486 # define INTVARDEF(name)
 487 # define INTDEF2(name, newname)
 488 # define INTVARDEF2(name, newname)
 489 #endif
 490
 491 /* The following macros are used for PLT bypassing within libc.so
 492    (and if needed other libraries similarly).
 493    First of all, you need to have the function prototyped somewhere,
 494    say in foo/foo.h:
 495
 496    int foo (int __bar);
 497
 498    If calls to foo within libc.so should always go to foo defined in libc.so,
 499    then in include/foo.h you add:
 500
 501    libc_hidden_proto (foo)
 502
 503    line and after the foo function definition:
 504
 505    int foo (int __bar)
 506    {
 507      return __bar;
 508    }
 509    libc_hidden_def (foo)
 510
 511    or
 512
 513    int foo (int __bar)
 514    {
 515      return __bar;
 516    }
 517    libc_hidden_weak (foo)
 518
 519    Similarly for global data.  If references to foo within libc.so should
 520    always go to foo defined in libc.so, then in include/foo.h you add:
 521
 522    libc_hidden_proto (foo)
 523
 524    line and after foo's definition:
 525
 526    int foo = INITIAL_FOO_VALUE;
 527    libc_hidden_data_def (foo)
 528
 529    or
 530
 531    int foo = INITIAL_FOO_VALUE;
 532    libc_hidden_data_weak (foo)
 533
 534    If foo is normally just an alias (strong or weak) to some other function,
 535    you should use the normal strong_alias first, then add libc_hidden_def
 536    or libc_hidden_weak:
 537
 538    int baz (int __bar)
 539    {
 540      return __bar;
 541    }
 542    strong_alias (baz, foo)
 543    libc_hidden_weak (foo)
 544
 545    If the function should be internal to multiple objects, say ld.so and
 546    libc.so, the best way is to use:
 547
 548    #if !defined NOT_IN_libc || defined IS_IN_rtld
 549    hidden_proto (foo)
 550    #endif
 551
 552    in include/foo.h and the normal macros at all function definitions
 553    depending on what DSO they belong to.
 554
 555    If versioned_symbol macro is used to define foo,
 556    libc_hidden_ver macro should be used, as in:
 557
 558    int __real_foo (int __bar)
 559    {
 560      return __bar;
 561    }
 562    versioned_symbol (libc, __real_foo, foo, GLIBC_2_1);
 563    libc_hidden_ver (__real_foo, foo)  */
 564
 565 #if defined SHARED && defined DO_VERSIONING && !defined NO_HIDDEN
 566 # ifndef __ASSEMBLER__
 567 #  define __hidden_proto_hiddenattr(attrs...) \
 568   __attribute__ ((visibility ("hidden"), ##attrs))
 569 #  define hidden_proto(name, attrs...) \
 570   __hidden_proto (name, __GI_##name, ##attrs)
 571 #  define __hidden_proto(name, internal, attrs...) \
 572   extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
 573   __hidden_proto_hiddenattr (attrs);
 574 #  define __hidden_asmname(name) \
 575   __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
 576 #  define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
 577 #  define __hidden_asmname2(prefix, name) #prefix name
 578 #  define __hidden_ver1(local, internal, name) \
 579   extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
 580   extern __typeof (name) __EI_##name \
 581         __attribute__((alias (__hidden_asmname (#local))))
 582 #  define hidden_ver(local, name)       __hidden_ver1(local, __GI_##name, name);
 583 #  define hidden_data_ver(local, name)  hidden_ver(local, name)
 584 #  define hidden_def(name)              __hidden_ver1(__GI_##name, name, name);
 585 #  define hidden_data_def(name)         hidden_def(name)
 586 #  define hidden_weak(name) \
 587         __hidden_ver1(__GI_##name, name, name) __attribute__((weak));
 588 #  define hidden_data_weak(name)        hidden_weak(name)
 589 # else
 590 /* For assembly, we need to do the opposite of what we do in C:
 591    in assembly gcc __REDIRECT stuff is not in place, so functions
 592    are defined by its normal name and we need to create the
 593    __GI_* alias to it, in C __REDIRECT causes the function definition
 594    to use __GI_* name and we need to add alias to the real name.
 595    There is no reason to use hidden_weak over hidden_def in assembly,
 596    but we provide it for consistency with the C usage.
 597    hidden_proto doesn't make sense for assembly but the equivalent
 598    is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET.  */
 599 #  define hidden_def(name)      strong_alias (name, __GI_##name)
 600 #  define hidden_weak(name)     hidden_def (name)
 601 #  define hidden_ver(local, name) strong_alias (local, __GI_##name)
 602 #  define hidden_data_def(name) strong_data_alias (name, __GI_##name)
 603 #  define hidden_data_weak(name)        hidden_data_def (name)
 604 #  define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
 605 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 606 #   define HIDDEN_JUMPTARGET(name) .__GI_##name
 607 #  else
 608 #   define HIDDEN_JUMPTARGET(name) __GI_##name
 609 #  endif
 610 # endif
 611 #else
 612 # ifndef __ASSEMBLER__
 613 #  define hidden_proto(name, attrs...)
 614 # else
 615 #  define HIDDEN_JUMPTARGET(name) JUMPTARGET(name)
 616 # endif /* Not  __ASSEMBLER__ */
 617 # define hidden_weak(name)
 618 # define hidden_def(name)
 619 # define hidden_ver(local, name)
 620 # define hidden_data_weak(name)
 621 # define hidden_data_def(name)
 622 # define hidden_data_ver(local, name)
 623 #endif
 624
 625 #if !defined NOT_IN_libc
 626 # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 627 # define libc_hidden_def(name) hidden_def (name)
 628 # define libc_hidden_weak(name) hidden_weak (name)
 629 # define libc_hidden_ver(local, name) hidden_ver (local, name)
 630 # define libc_hidden_data_def(name) hidden_data_def (name)
 631 # define libc_hidden_data_weak(name) hidden_data_weak (name)
 632 # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
 633 #else
 634 # define libc_hidden_proto(name, attrs...)
 635 # define libc_hidden_def(name)
 636 # define libc_hidden_weak(name)
 637 # define libc_hidden_ver(local, name)
 638 # define libc_hidden_data_def(name)
 639 # define libc_hidden_data_weak(name)
 640 # define libc_hidden_data_ver(local, name)
 641 #endif
 642
 643 #if defined NOT_IN_libc && defined IS_IN_rtld
 644 # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 645 # define rtld_hidden_def(name) hidden_def (name)
 646 # define rtld_hidden_weak(name) hidden_weak (name)
 647 # define rtld_hidden_ver(local, name) hidden_ver (local, name)
 648 # define rtld_hidden_data_def(name) hidden_data_def (name)
 649 # define rtld_hidden_data_weak(name) hidden_data_weak (name)
 650 # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name)
 651 #else
 652 # define rtld_hidden_proto(name, attrs...)
 653 # define rtld_hidden_def(name)
 654 # define rtld_hidden_weak(name)
 655 # define rtld_hidden_ver(local, name)
 656 # define rtld_hidden_data_def(name)
 657 # define rtld_hidden_data_weak(name)
 658 # define rtld_hidden_data_ver(local, name)
 659 #endif
 660
 661 #if defined NOT_IN_libc && defined IS_IN_libm
 662 # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 663 # define libm_hidden_def(name) hidden_def (name)
 664 # define libm_hidden_weak(name) hidden_weak (name)
 665 # define libm_hidden_ver(local, name) hidden_ver (local, name)
 666 # define libm_hidden_data_def(name) hidden_data_def (name)
 667 # define libm_hidden_data_weak(name) hidden_data_weak (name)
 668 # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name)
 669 #else
 670 # define libm_hidden_proto(name, attrs...)
 671 # define libm_hidden_def(name)
 672 # define libm_hidden_weak(name)
 673 # define libm_hidden_ver(local, name)
 674 # define libm_hidden_data_def(name)
 675 # define libm_hidden_data_weak(name)
 676 # define libm_hidden_data_ver(local, name)
 677 #endif
 678
 679 #if defined NOT_IN_libc && defined IS_IN_libresolv
 680 # define libresolv_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 681 # define libresolv_hidden_def(name) hidden_def (name)
 682 # define libresolv_hidden_weak(name) hidden_weak (name)
 683 # define libresolv_hidden_ver(local, name) hidden_ver (local, name)
 684 # define libresolv_hidden_data_def(name) hidden_data_def (name)
 685 # define libresolv_hidden_data_weak(name) hidden_data_weak (name)
 686 # define libresolv_hidden_data_ver(local, name) hidden_data_ver (local, name)
 687 #else
 688 # define libresolv_hidden_proto(name, attrs...)
 689 # define libresolv_hidden_def(name)
 690 # define libresolv_hidden_weak(name)
 691 # define libresolv_hidden_ver(local, name)
 692 # define libresolv_hidden_data_def(name)
 693 # define libresolv_hidden_data_weak(name)
 694 # define libresolv_hidden_data_ver(local, name)
 695 #endif
 696
 697 #if defined NOT_IN_libc && defined IS_IN_librt
 698 # define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 699 # define librt_hidden_def(name) hidden_def (name)
 700 # define librt_hidden_weak(name) hidden_weak (name)
 701 # define librt_hidden_ver(local, name) hidden_ver (local, name)
 702 # define librt_hidden_data_def(name) hidden_data_def (name)
 703 # define librt_hidden_data_weak(name) hidden_data_weak (name)
 704 # define librt_hidden_data_ver(local, name) hidden_data_ver (local, name)
 705 #else
 706 # define librt_hidden_proto(name, attrs...)
 707 # define librt_hidden_def(name)
 708 # define librt_hidden_weak(name)
 709 # define librt_hidden_ver(local, name)
 710 # define librt_hidden_data_def(name)
 711 # define librt_hidden_data_weak(name)
 712 # define librt_hidden_data_ver(local, name)
 713 #endif
 714
 715 #if defined NOT_IN_libc && defined IS_IN_libdl
 716 # define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 717 # define libdl_hidden_def(name) hidden_def (name)
 718 # define libdl_hidden_weak(name) hidden_weak (name)
 719 # define libdl_hidden_ver(local, name) hidden_ver (local, name)
 720 # define libdl_hidden_data_def(name) hidden_data_def (name)
 721 # define libdl_hidden_data_weak(name) hidden_data_weak (name)
 722 # define libdl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 723 #else
 724 # define libdl_hidden_proto(name, attrs...)
 725 # define libdl_hidden_def(name)
 726 # define libdl_hidden_weak(name)
 727 # define libdl_hidden_ver(local, name)
 728 # define libdl_hidden_data_def(name)
 729 # define libdl_hidden_data_weak(name)
 730 # define libdl_hidden_data_ver(local, name)
 731 #endif
 732
 733 #if defined NOT_IN_libc && defined IS_IN_libnss_files
 734 # define libnss_files_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 735 # define libnss_files_hidden_def(name) hidden_def (name)
 736 # define libnss_files_hidden_weak(name) hidden_weak (name)
 737 # define libnss_files_hidden_ver(local, name) hidden_ver (local, name)
 738 # define libnss_files_hidden_data_def(name) hidden_data_def (name)
 739 # define libnss_files_hidden_data_weak(name) hidden_data_weak (name)
 740 # define libnss_files_hidden_data_ver(local, name) hidden_data_ver(local, name)
 741 #else
 742 # define libnss_files_hidden_proto(name, attrs...)
 743 # define libnss_files_hidden_def(name)
 744 # define libnss_files_hidden_weak(name)
 745 # define libnss_files_hidden_ver(local, name)
 746 # define libnss_files_hidden_data_def(name)
 747 # define libnss_files_hidden_data_weak(name)
 748 # define libnss_files_hidden_data_ver(local, name)
 749 #endif
 750
 751 #if defined NOT_IN_libc && defined IS_IN_libnsl
 752 # define libnsl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 753 # define libnsl_hidden_def(name) hidden_def (name)
 754 # define libnsl_hidden_weak(name) hidden_weak (name)
 755 # define libnsl_hidden_ver(local, name) hidden_ver (local, name)
 756 # define libnsl_hidden_data_def(name) hidden_data_def (name)
 757 # define libnsl_hidden_data_weak(name) hidden_data_weak (name)
 758 # define libnsl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 759 #else
 760 # define libnsl_hidden_proto(name, attrs...)
 761 # define libnsl_hidden_def(name)
 762 # define libnsl_hidden_weak(name)
 763 # define libnsl_hidden_ver(local, name)
 764 # define libnsl_hidden_data_def(name)
 765 # define libnsl_hidden_data_weak(name)
 766 # define libnsl_hidden_data_ver(local, name)
 767 #endif
 768
 769 #if defined NOT_IN_libc && defined IS_IN_libnss_nisplus
 770 # define libnss_nisplus_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 771 # define libnss_nisplus_hidden_def(name) hidden_def (name)
 772 # define libnss_nisplus_hidden_weak(name) hidden_weak (name)
 773 # define libnss_nisplus_hidden_ver(local, name) hidden_ver (local, name)
 774 # define libnss_nisplus_hidden_data_def(name) hidden_data_def (name)
 775 # define libnss_nisplus_hidden_data_weak(name) hidden_data_weak (name)
 776 # define libnss_nisplus_hidden_data_ver(local, name) hidden_data_ver (local, name)
 777 #else
 778 # define libnss_nisplus_hidden_proto(name, attrs...)
 779 # define libnss_nisplus_hidden_def(name)
 780 # define libnss_nisplus_hidden_weak(name)
 781 # define libnss_nisplus_hidden_ver(local, name)
 782 # define libnss_nisplus_hidden_data_def(name)
 783 # define libnss_nisplus_hidden_data_weak(name)
 784 # define libnss_nisplus_hidden_data_ver(local, name)
 785 #endif
 786
 787 #ifdef HAVE_BUILTIN_REDIRECTION
 788 # define libc_hidden_builtin_proto(name, attrs...) libc_hidden_proto (name, ##attrs)
 789 # define libc_hidden_builtin_def(name) libc_hidden_def (name)
 790 # define libc_hidden_builtin_weak(name) libc_hidden_weak (name)
 791 # define libc_hidden_builtin_ver(local, name) libc_hidden_ver (local, name)
 792 # ifdef __ASSEMBLER__
 793 #  define HIDDEN_BUILTIN_JUMPTARGET(name) HIDDEN_JUMPTARGET(name)
 794 # endif
 795 #else
 796 # define libc_hidden_builtin_proto(name, attrs...)
 797 # define libc_hidden_builtin_def(name)
 798 # define libc_hidden_builtin_weak(name)
 799 # define libc_hidden_builtin_ver(local, name)
 800 # ifdef __ASSEMBLER__
 801 #  define HIDDEN_BUILTIN_JUMPTARGET(name) JUMPTARGET(name)
 802 # endif
 803 #endif
 804
 805 #if defined NOT_IN_libc && defined IS_IN_libutil
 806 # define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 807 # define libutil_hidden_def(name) hidden_def (name)
 808 # define libutil_hidden_weak(name) hidden_weak (name)
 809 # define libutil_hidden_ver(local, name) hidden_ver (local, name)
 810 # define libutil_hidden_data_def(name) hidden_data_def (name)
 811 # define libutil_hidden_data_weak(name) hidden_data_weak (name)
 812 # define libutil_hidden_data_ver(local, name) hidden_data_ver (local, name)
 813 #else
 814 # define libutil_hidden_proto(name, attrs...)
 815 # define libutil_hidden_def(name)
 816 # define libutil_hidden_weak(name)
 817 # define libutil_hidden_ver(local, name)
 818 # define libutil_hidden_data_def(name)
 819 # define libutil_hidden_data_weak(name)
 820 # define libutil_hidden_data_ver(local, name)
 821 #endif
 822
 823 /* Get some dirty hacks.  */
 824 #include <symbol-hacks.h>
 825
 826 /* Move compatibility symbols out of the way by placing them all in a
 827    special section.  */
 828 #ifndef __ASSEMBLER__
 829 # define attribute_compat_text_section \
 830     __attribute__ ((section (".text.compat")))
 831 # define attribute_compat_data_section \
 832     __attribute__ ((section (".data.compat")))
 833 #else
 834 # define compat_text_section .section ".text.compat", "ax";
 835 # define compat_data_section .section ".data.compat", "aw";
 836 #endif
 837
 838 #endif /* libc-symbols.h */