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) 1995-2013 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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _LIBC_SYMBOLS_H
  21 #define _LIBC_SYMBOLS_H 1
  22
  23 /* This file's macros are included implicitly in the compilation of every
  24    file in the C library by -imacros.
  25
  26    We include config.h which is generated by configure.
  27    It should define for us the following symbols:
  28
  29    * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'.
  30    * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'.
  31    * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'.
  32
  33    */
  34
  35 /* This is defined for the compilation of all C library code.  features.h
  36    tests this to avoid inclusion of stubs.h while compiling the library,
  37    before stubs.h has been generated.  Some library code that is shared
  38    with other packages also tests this symbol to see if it is being
  39    compiled as part of the C library.  We must define this before including
  40    config.h, because it makes some definitions conditional on whether libc
  41    itself is being compiled, or just some generator program.  */
  42 #define _LIBC   1
  43
  44 /* Enable declarations of GNU extensions, since we are compiling them.  */
  45 #define _GNU_SOURCE     1
  46 /* And we also need the data for the reentrant functions.  */
  47 #define _REENTRANT      1
  48
  49 #include <config.h>
  50
  51 /* The symbols in all the user (non-_) macros are C symbols.  */
  52
  53 #if !defined HAVE_ASM_WEAK_DIRECTIVE && !defined HAVE_ASM_WEAKEXT_DIRECTIVE
  54 # error "weak symbol support needed"
  55 #endif
  56
  57 #ifndef __SYMBOL_PREFIX
  58 # define __SYMBOL_PREFIX
  59 #endif
  60
  61 #ifndef C_SYMBOL_NAME
  62 # define C_SYMBOL_NAME(name) name
  63 #endif
  64
  65 #ifndef ASM_LINE_SEP
  66 # define ASM_LINE_SEP ;
  67 #endif
  68
  69 #ifdef HAVE_ASM_GLOBAL_DOT_NAME
  70 # ifndef C_SYMBOL_DOT_NAME
  71 #  if defined __GNUC__ && defined __GNUC_MINOR__ \
  72       && (__GNUC__ << 16) + __GNUC_MINOR__ >= (3 << 16) + 1
  73 #   define C_SYMBOL_DOT_NAME(name) .name
  74 #  else
  75 #   define C_SYMBOL_DOT_NAME(name) .##name
  76 #  endif
  77 # endif
  78 #endif
  79
  80 #ifndef __ASSEMBLER__
  81 /* GCC understands weak symbols and aliases; use its interface where
  82    possible, instead of embedded assembly language.  */
  83
  84 /* Define ALIASNAME as a strong alias for NAME.  */
  85 # define strong_alias(name, aliasname) _strong_alias(name, aliasname)
  86 # define _strong_alias(name, aliasname) \
  87   extern __typeof (name) aliasname __attribute__ ((alias (#name)));
  88
  89 /* This comes between the return type and function name in
  90    a function definition to make that definition weak.  */
  91 # define weak_function __attribute__ ((weak))
  92 # define weak_const_function __attribute__ ((weak, __const__))
  93
  94 /* Define ALIASNAME as a weak alias for NAME.
  95    If weak aliases are not available, this defines a strong alias.  */
  96 # define weak_alias(name, aliasname) _weak_alias (name, aliasname)
  97 # define _weak_alias(name, aliasname) \
  98   extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
  99
 100 /* Same as WEAK_ALIAS, but mark symbol as hidden.  */
 101 # define weak_hidden_alias(name, aliasname) \
 102   _weak_hidden_alias (name, aliasname)
 103 # define _weak_hidden_alias(name, aliasname) \
 104   extern __typeof (name) aliasname \
 105     __attribute__ ((weak, alias (#name), __visibility__ ("hidden")));
 106
 107 /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined).  */
 108 # define weak_extern(symbol) _weak_extern (weak symbol)
 109 # define _weak_extern(expr) _Pragma (#expr)
 110
 111
 112 #else /* __ASSEMBLER__ */
 113
 114 # ifdef HAVE_ASM_SET_DIRECTIVE
 115 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 116 #   define strong_alias(original, alias)                                \
 117   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 118   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP      \
 119   .globl C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP         \
 120   .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original)
 121 #   define strong_data_alias(original, alias)                           \
 122   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 123   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 124 #  else
 125 #   define strong_alias(original, alias)                                \
 126   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 127   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 128 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 129 #  endif
 130 # else
 131 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 132 #   define strong_alias(original, alias)                                \
 133   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 134   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 135   .globl C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP         \
 136   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 137 #   define strong_data_alias(original, alias)                           \
 138   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 139   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 140 #  else
 141 #   define strong_alias(original, alias)                                \
 142   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 143   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 144 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 145 #  endif
 146 # endif
 147
 148 # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
 149 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 150 #   define weak_alias(original, alias)                                  \
 151   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \
 152   .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
 153 #  else
 154 #   define weak_alias(original, alias)                                  \
 155   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
 156 #  endif
 157 #  define weak_extern(symbol)                                           \
 158   .weakext C_SYMBOL_NAME (symbol)
 159
 160 # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 161
 162 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 163 #   define weak_alias(original, alias)                                  \
 164   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 165   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 166   .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP                          \
 167   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 168 #  else
 169 #   define weak_alias(original, alias)                                  \
 170   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 171   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 172 #  endif
 173
 174 #  define weak_extern(symbol)                                           \
 175   .weak C_SYMBOL_NAME (symbol)
 176
 177 # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 178
 179 #endif /* __ASSEMBLER__ */
 180
 181 /* On some platforms we can make internal function calls (i.e., calls of
 182    functions not exported) a bit faster by using a different calling
 183    convention.  */
 184 #ifndef internal_function
 185 # define internal_function      /* empty */
 186 #endif
 187
 188 /* Determine the return address.  */
 189 #define RETURN_ADDRESS(nr) \
 190   __builtin_extract_return_addr (__builtin_return_address (nr))
 191
 192 /* When a reference to SYMBOL is encountered, the linker will emit a
 193    warning message MSG.  */
 194 /* We want the .gnu.warning.SYMBOL section to be unallocated.  */
 195 #ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
 196 # define __make_section_unallocated(section_string)     \
 197   asm (".section " section_string "\n\t.previous");
 198 #elif defined HAVE_ASM_POPSECTION_DIRECTIVE
 199 # define __make_section_unallocated(section_string)     \
 200   asm (".pushsection " section_string "\n\t.popsection");
 201 #else
 202 # define __make_section_unallocated(section_string)
 203 #endif
 204
 205 /* Tacking on "\n\t#" to the section name makes gcc put it's bogus
 206    section attributes on what looks like a comment to the assembler.  */
 207 #ifdef HAVE_SECTION_QUOTES
 208 # define __sec_comment "\"\n\t#\""
 209 #else
 210 # define __sec_comment "\n\t#"
 211 #endif
 212 #define link_warning(symbol, msg) \
 213   __make_section_unallocated (".gnu.warning." #symbol) \
 214   static const char __evoke_link_warning_##symbol[]     \
 215     __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
 216     = msg;
 217 #define libc_freeres_ptr(decl) \
 218   __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
 219   decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
 220 #define __libc_freeres_fn_section \
 221   __attribute__ ((section ("__libc_freeres_fn")))
 222
 223 #define libc_freeres_fn(name)   \
 224   static void name (void) __attribute_used__ __libc_freeres_fn_section; \
 225   text_set_element (__libc_subfreeres, name);                           \
 226   static void name (void)
 227
 228 /* A canned warning for sysdeps/stub functions.  */
 229 #define stub_warning(name) \
 230   __make_section_unallocated (".gnu.glibc-stub." #name) \
 231   link_warning (name, #name " is not implemented and will always fail")
 232
 233 /* Warning for linking functions calling dlopen into static binaries.  */
 234 #ifdef SHARED
 235 #define static_link_warning(name)
 236 #else
 237 #define static_link_warning(name) static_link_warning1(name)
 238 #define static_link_warning1(name) \
 239   link_warning(name, "Using '" #name "' in statically linked applications \
 240 requires at runtime the shared libraries from the glibc version used \
 241 for linking")
 242 #endif
 243
 244 /* Declare SYMBOL to be TYPE (`function' or `object') of SIZE bytes
 245    alias to ORIGINAL, when the assembler supports such declarations
 246    (such as in ELF).
 247    This is only necessary when defining something in assembly, or playing
 248    funny alias games where the size should be other than what the compiler
 249    thinks it is.  */
 250 #define declare_symbol_alias(symbol, original, type, size) \
 251   declare_symbol_alias_1 (symbol, original, type, size)
 252 #ifdef __ASSEMBLER__
 253 # define declare_symbol_alias_1(symbol, original, type, size) \
 254    strong_alias (original, symbol); \
 255    .type C_SYMBOL_NAME (symbol), %##type; \
 256    .size C_SYMBOL_NAME (symbol), size
 257 #else /* Not __ASSEMBLER__.  */
 258 # define declare_symbol_alias_1(symbol, original, type, size) \
 259    asm (".globl " __SYMBOL_PREFIX #symbol \
 260         "\n\t" declare_symbol_alias_1_alias (symbol, original) \
 261         "\n\t.type " __SYMBOL_PREFIX #symbol ", " \
 262         "%" #type \
 263         "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size);
 264 # ifdef HAVE_ASM_SET_DIRECTIVE
 265 #  define declare_symbol_alias_1_alias(symbol, original) \
 266      ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX #original
 267 # else
 268 #  define declare_symbol_alias_1_alias(symbol, original) \
 269      __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX #original
 270 # endif /* HAVE_ASM_SET_DIRECTIVE */
 271 #endif /* __ASSEMBLER__ */
 272
 273
 274 /*
 275 \f
 276 */
 277
 278 /* Symbol set support macros.  */
 279
 280 /* Make SYMBOL, which is in the text segment, an element of SET.  */
 281 #define text_set_element(set, symbol)   _elf_set_element(set, symbol)
 282 /* Make SYMBOL, which is in the data segment, an element of SET.  */
 283 #define data_set_element(set, symbol)   _elf_set_element(set, symbol)
 284 /* Make SYMBOL, which is in the bss segment, an element of SET.  */
 285 #define bss_set_element(set, symbol)    _elf_set_element(set, symbol)
 286
 287 /* These are all done the same way in ELF.
 288    There is a new section created for each set.  */
 289 #ifdef SHARED
 290 /* When building a shared library, make the set section writable,
 291    because it will need to be relocated at run time anyway.  */
 292 # define _elf_set_element(set, symbol) \
 293   static const void *__elf_set_##set##_element_##symbol##__ \
 294     __attribute__ ((used, section (#set))) = &(symbol)
 295 #else
 296 # define _elf_set_element(set, symbol) \
 297   static const void *const __elf_set_##set##_element_##symbol##__ \
 298     __attribute__ ((used, section (#set))) = &(symbol)
 299 #endif
 300
 301 /* Define SET as a symbol set.  This may be required (it is in a.out) to
 302    be able to use the set's contents.  */
 303 #define symbol_set_define(set)  symbol_set_declare(set)
 304
 305 /* Declare SET for use in this module, if defined in another module.
 306    In a shared library, this is always local to that shared object.
 307    For static linking, the set might be wholly absent and so we use
 308    weak references.  */
 309 #define symbol_set_declare(set) \
 310   extern char const __start_##set[] __symbol_set_attribute; \
 311   extern char const __stop_##set[] __symbol_set_attribute;
 312 #ifdef SHARED
 313 # define __symbol_set_attribute attribute_hidden
 314 #else
 315 # define __symbol_set_attribute __attribute__ ((weak))
 316 #endif
 317
 318 /* Return a pointer (void *const *) to the first element of SET.  */
 319 #define symbol_set_first_element(set)   ((void *const *) (&__start_##set))
 320
 321 /* Return true iff PTR (a void *const *) has been incremented
 322    past the last element in SET.  */
 323 #define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
 324
 325 #ifdef SHARED
 326 # define symbol_version(real, name, version) \
 327      _symbol_version(real, name, version)
 328 # define default_symbol_version(real, name, version) \
 329      _default_symbol_version(real, name, version)
 330 # ifdef __ASSEMBLER__
 331 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 332 #   define _symbol_version(real, name, version) \
 333      .symver real, name##@##version ASM_LINE_SEP                        \
 334      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##version)
 335 #   define _default_symbol_version(real, name, version) \
 336      .symver real, name##@##@##version ASM_LINE_SEP                     \
 337      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##@##version)
 338 #  else
 339 #   define _symbol_version(real, name, version) \
 340      .symver real, name##@##version
 341 #   define _default_symbol_version(real, name, version) \
 342      .symver real, name##@##@##version
 343 #  endif
 344 # else
 345 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 346 #   define _symbol_version(real, name, version) \
 347      __asm__ (".symver " #real "," #name "@" #version "\n\t"    \
 348               ".symver ." #real ",." #name "@" #version)
 349 #   define _default_symbol_version(real, name, version) \
 350      __asm__ (".symver " #real "," #name "@@" #version "\n\t"   \
 351               ".symver ." #real ",." #name "@@" #version)
 352 #  else
 353 #   define _symbol_version(real, name, version) \
 354      __asm__ (".symver " #real "," #name "@" #version)
 355 #   define _default_symbol_version(real, name, version) \
 356      __asm__ (".symver " #real "," #name "@@" #version)
 357 #  endif
 358 # endif
 359 #else
 360 # define symbol_version(real, name, version)
 361 # define default_symbol_version(real, name, version) \
 362   strong_alias(real, name)
 363 #endif
 364
 365 #if defined SHARED || defined LIBC_NONSHARED
 366 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 367 #else
 368 # define attribute_hidden
 369 #endif
 370
 371 #define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
 372
 373 #define attribute_relro __attribute__ ((section (".data.rel.ro")))
 374
 375 /* Handling on non-exported internal names.  We have to do this only
 376    for shared code.  */
 377 #ifdef SHARED
 378 # define INTUSE(name) name##_internal
 379 # define INTDEF(name) strong_alias (name, name##_internal)
 380 # define INTVARDEF(name) \
 381   _INTVARDEF (name, name##_internal)
 382 # define _INTVARDEF(name, aliasname) \
 383   extern __typeof (name) aliasname __attribute__ ((alias (#name), \
 384                                                    visibility ("hidden")));
 385 # define INTDEF2(name, newname) strong_alias (name, newname##_internal)
 386 # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal)
 387 #else
 388 # define INTUSE(name) name
 389 # define INTDEF(name)
 390 # define INTVARDEF(name)
 391 # define INTDEF2(name, newname)
 392 # define INTVARDEF2(name, newname)
 393 #endif
 394
 395 /* The following macros are used for PLT bypassing within libc.so
 396    (and if needed other libraries similarly).
 397    First of all, you need to have the function prototyped somewhere,
 398    say in foo/foo.h:
 399
 400    int foo (int __bar);
 401
 402    If calls to foo within libc.so should always go to foo defined in libc.so,
 403    then in include/foo.h you add:
 404
 405    libc_hidden_proto (foo)
 406
 407    line and after the foo function definition:
 408
 409    int foo (int __bar)
 410    {
 411      return __bar;
 412    }
 413    libc_hidden_def (foo)
 414
 415    or
 416
 417    int foo (int __bar)
 418    {
 419      return __bar;
 420    }
 421    libc_hidden_weak (foo)
 422
 423    Similarly for global data.  If references to foo within libc.so should
 424    always go to foo defined in libc.so, then in include/foo.h you add:
 425
 426    libc_hidden_proto (foo)
 427
 428    line and after foo's definition:
 429
 430    int foo = INITIAL_FOO_VALUE;
 431    libc_hidden_data_def (foo)
 432
 433    or
 434
 435    int foo = INITIAL_FOO_VALUE;
 436    libc_hidden_data_weak (foo)
 437
 438    If foo is normally just an alias (strong or weak) to some other function,
 439    you should use the normal strong_alias first, then add libc_hidden_def
 440    or libc_hidden_weak:
 441
 442    int baz (int __bar)
 443    {
 444      return __bar;
 445    }
 446    strong_alias (baz, foo)
 447    libc_hidden_weak (foo)
 448
 449    If the function should be internal to multiple objects, say ld.so and
 450    libc.so, the best way is to use:
 451
 452    #if !defined NOT_IN_libc || defined IS_IN_rtld
 453    hidden_proto (foo)
 454    #endif
 455
 456    in include/foo.h and the normal macros at all function definitions
 457    depending on what DSO they belong to.
 458
 459    If versioned_symbol macro is used to define foo,
 460    libc_hidden_ver macro should be used, as in:
 461
 462    int __real_foo (int __bar)
 463    {
 464      return __bar;
 465    }
 466    versioned_symbol (libc, __real_foo, foo, GLIBC_2_1);
 467    libc_hidden_ver (__real_foo, foo)  */
 468
 469 #if defined SHARED && !defined NO_HIDDEN
 470 # ifndef __ASSEMBLER__
 471 #  define __hidden_proto_hiddenattr(attrs...) \
 472   __attribute__ ((visibility ("hidden"), ##attrs))
 473 #  define hidden_proto(name, attrs...) \
 474   __hidden_proto (name, __GI_##name, ##attrs)
 475 #  define __hidden_proto(name, internal, attrs...) \
 476   extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
 477   __hidden_proto_hiddenattr (attrs);
 478 #  define __hidden_asmname(name) \
 479   __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
 480 #  define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
 481 #  define __hidden_asmname2(prefix, name) #prefix name
 482 #  define __hidden_ver1(local, internal, name) \
 483   extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
 484   extern __typeof (name) __EI_##name \
 485         __attribute__((alias (__hidden_asmname (#local))))
 486 #  define hidden_ver(local, name)       __hidden_ver1(local, __GI_##name, name);
 487 #  define hidden_data_ver(local, name)  hidden_ver(local, name)
 488 #  define hidden_def(name)              __hidden_ver1(__GI_##name, name, name);
 489 #  define hidden_data_def(name)         hidden_def(name)
 490 #  define hidden_weak(name) \
 491         __hidden_ver1(__GI_##name, name, name) __attribute__((weak));
 492 #  define hidden_data_weak(name)        hidden_weak(name)
 493 #  define hidden_nolink(name, lib, version) \
 494   __hidden_nolink1 (__GI_##name, __EI_##name, name, VERSION_##lib##_##version)
 495 #  define __hidden_nolink1(local, internal, name, version) \
 496   __hidden_nolink2 (local, internal, name, version)
 497 #  define __hidden_nolink2(local, internal, name, version) \
 498   extern __typeof (name) internal __attribute__ ((alias (#local))); \
 499   __hidden_nolink3 (local, internal, #name "@" #version)
 500 #  define __hidden_nolink3(local, internal, vername) \
 501   __asm__ (".symver " #internal ", " vername);
 502 # else
 503 /* For assembly, we need to do the opposite of what we do in C:
 504    in assembly gcc __REDIRECT stuff is not in place, so functions
 505    are defined by its normal name and we need to create the
 506    __GI_* alias to it, in C __REDIRECT causes the function definition
 507    to use __GI_* name and we need to add alias to the real name.
 508    There is no reason to use hidden_weak over hidden_def in assembly,
 509    but we provide it for consistency with the C usage.
 510    hidden_proto doesn't make sense for assembly but the equivalent
 511    is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET.  */
 512 #  define hidden_def(name)      strong_alias (name, __GI_##name)
 513 #  define hidden_weak(name)     hidden_def (name)
 514 #  define hidden_ver(local, name) strong_alias (local, __GI_##name)
 515 #  define hidden_data_def(name) strong_data_alias (name, __GI_##name)
 516 #  define hidden_data_weak(name)        hidden_data_def (name)
 517 #  define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
 518 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 519 #   define HIDDEN_JUMPTARGET(name) .__GI_##name
 520 #  else
 521 #   define HIDDEN_JUMPTARGET(name) __GI_##name
 522 #  endif
 523 # endif
 524 #else
 525 # ifndef __ASSEMBLER__
 526 #  define hidden_proto(name, attrs...)
 527 # else
 528 #  define HIDDEN_JUMPTARGET(name) JUMPTARGET(name)
 529 # endif /* Not  __ASSEMBLER__ */
 530 # define hidden_weak(name)
 531 # define hidden_def(name)
 532 # define hidden_ver(local, name)
 533 # define hidden_data_weak(name)
 534 # define hidden_data_def(name)
 535 # define hidden_data_ver(local, name)
 536 # define hidden_nolink(name, lib, version)
 537 #endif
 538
 539 #if !defined NOT_IN_libc
 540 # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 541 # define libc_hidden_def(name) hidden_def (name)
 542 # define libc_hidden_weak(name) hidden_weak (name)
 543 # ifdef LINK_OBSOLETE_RPC
 544    /* libc_hidden_nolink_sunrpc should only get used in sunrpc code.  */
 545 #  define libc_hidden_nolink_sunrpc(name, version) hidden_def (name)
 546 # else
 547 #  define libc_hidden_nolink_sunrpc(name, version) hidden_nolink (name, libc, version)
 548 # endif
 549 # define libc_hidden_ver(local, name) hidden_ver (local, name)
 550 # define libc_hidden_data_def(name) hidden_data_def (name)
 551 # define libc_hidden_data_weak(name) hidden_data_weak (name)
 552 # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
 553 #else
 554 # define libc_hidden_proto(name, attrs...)
 555 # define libc_hidden_def(name)
 556 # define libc_hidden_weak(name)
 557 # define libc_hidden_ver(local, name)
 558 # define libc_hidden_data_def(name)
 559 # define libc_hidden_data_weak(name)
 560 # define libc_hidden_data_ver(local, name)
 561 #endif
 562
 563 #if defined NOT_IN_libc && defined IS_IN_rtld
 564 # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 565 # define rtld_hidden_def(name) hidden_def (name)
 566 # define rtld_hidden_weak(name) hidden_weak (name)
 567 # define rtld_hidden_ver(local, name) hidden_ver (local, name)
 568 # define rtld_hidden_data_def(name) hidden_data_def (name)
 569 # define rtld_hidden_data_weak(name) hidden_data_weak (name)
 570 # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name)
 571 #else
 572 # define rtld_hidden_proto(name, attrs...)
 573 # define rtld_hidden_def(name)
 574 # define rtld_hidden_weak(name)
 575 # define rtld_hidden_ver(local, name)
 576 # define rtld_hidden_data_def(name)
 577 # define rtld_hidden_data_weak(name)
 578 # define rtld_hidden_data_ver(local, name)
 579 #endif
 580
 581 #if defined NOT_IN_libc && defined IS_IN_libm
 582 # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 583 # define libm_hidden_def(name) hidden_def (name)
 584 # define libm_hidden_weak(name) hidden_weak (name)
 585 # define libm_hidden_ver(local, name) hidden_ver (local, name)
 586 # define libm_hidden_data_def(name) hidden_data_def (name)
 587 # define libm_hidden_data_weak(name) hidden_data_weak (name)
 588 # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name)
 589 #else
 590 # define libm_hidden_proto(name, attrs...)
 591 # define libm_hidden_def(name)
 592 # define libm_hidden_weak(name)
 593 # define libm_hidden_ver(local, name)
 594 # define libm_hidden_data_def(name)
 595 # define libm_hidden_data_weak(name)
 596 # define libm_hidden_data_ver(local, name)
 597 #endif
 598
 599 #if defined NOT_IN_libc && defined IS_IN_libresolv
 600 # define libresolv_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 601 # define libresolv_hidden_def(name) hidden_def (name)
 602 # define libresolv_hidden_weak(name) hidden_weak (name)
 603 # define libresolv_hidden_ver(local, name) hidden_ver (local, name)
 604 # define libresolv_hidden_data_def(name) hidden_data_def (name)
 605 # define libresolv_hidden_data_weak(name) hidden_data_weak (name)
 606 # define libresolv_hidden_data_ver(local, name) hidden_data_ver (local, name)
 607 #else
 608 # define libresolv_hidden_proto(name, attrs...)
 609 # define libresolv_hidden_def(name)
 610 # define libresolv_hidden_weak(name)
 611 # define libresolv_hidden_ver(local, name)
 612 # define libresolv_hidden_data_def(name)
 613 # define libresolv_hidden_data_weak(name)
 614 # define libresolv_hidden_data_ver(local, name)
 615 #endif
 616
 617 #if defined NOT_IN_libc && defined IS_IN_librt
 618 # define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 619 # define librt_hidden_def(name) hidden_def (name)
 620 # define librt_hidden_weak(name) hidden_weak (name)
 621 # define librt_hidden_ver(local, name) hidden_ver (local, name)
 622 # define librt_hidden_data_def(name) hidden_data_def (name)
 623 # define librt_hidden_data_weak(name) hidden_data_weak (name)
 624 # define librt_hidden_data_ver(local, name) hidden_data_ver (local, name)
 625 #else
 626 # define librt_hidden_proto(name, attrs...)
 627 # define librt_hidden_def(name)
 628 # define librt_hidden_weak(name)
 629 # define librt_hidden_ver(local, name)
 630 # define librt_hidden_data_def(name)
 631 # define librt_hidden_data_weak(name)
 632 # define librt_hidden_data_ver(local, name)
 633 #endif
 634
 635 #if defined NOT_IN_libc && defined IS_IN_libdl
 636 # define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 637 # define libdl_hidden_def(name) hidden_def (name)
 638 # define libdl_hidden_weak(name) hidden_weak (name)
 639 # define libdl_hidden_ver(local, name) hidden_ver (local, name)
 640 # define libdl_hidden_data_def(name) hidden_data_def (name)
 641 # define libdl_hidden_data_weak(name) hidden_data_weak (name)
 642 # define libdl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 643 #else
 644 # define libdl_hidden_proto(name, attrs...)
 645 # define libdl_hidden_def(name)
 646 # define libdl_hidden_weak(name)
 647 # define libdl_hidden_ver(local, name)
 648 # define libdl_hidden_data_def(name)
 649 # define libdl_hidden_data_weak(name)
 650 # define libdl_hidden_data_ver(local, name)
 651 #endif
 652
 653 #if defined NOT_IN_libc && defined IS_IN_libnss_files
 654 # define libnss_files_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 655 # define libnss_files_hidden_def(name) hidden_def (name)
 656 # define libnss_files_hidden_weak(name) hidden_weak (name)
 657 # define libnss_files_hidden_ver(local, name) hidden_ver (local, name)
 658 # define libnss_files_hidden_data_def(name) hidden_data_def (name)
 659 # define libnss_files_hidden_data_weak(name) hidden_data_weak (name)
 660 # define libnss_files_hidden_data_ver(local, name) hidden_data_ver(local, name)
 661 #else
 662 # define libnss_files_hidden_proto(name, attrs...)
 663 # define libnss_files_hidden_def(name)
 664 # define libnss_files_hidden_weak(name)
 665 # define libnss_files_hidden_ver(local, name)
 666 # define libnss_files_hidden_data_def(name)
 667 # define libnss_files_hidden_data_weak(name)
 668 # define libnss_files_hidden_data_ver(local, name)
 669 #endif
 670
 671 #if defined NOT_IN_libc && defined IS_IN_libnsl
 672 # define libnsl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 673 # define libnsl_hidden_def(name) hidden_def (name)
 674 # define libnsl_hidden_weak(name) hidden_weak (name)
 675 # define libnsl_hidden_ver(local, name) hidden_ver (local, name)
 676 # define libnsl_hidden_data_def(name) hidden_data_def (name)
 677 # define libnsl_hidden_data_weak(name) hidden_data_weak (name)
 678 # define libnsl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 679 #else
 680 # define libnsl_hidden_proto(name, attrs...)
 681 # define libnsl_hidden_def(name)
 682 # define libnsl_hidden_weak(name)
 683 # define libnsl_hidden_ver(local, name)
 684 # define libnsl_hidden_data_def(name)
 685 # define libnsl_hidden_data_weak(name)
 686 # define libnsl_hidden_data_ver(local, name)
 687 #endif
 688
 689 #if defined NOT_IN_libc && defined IS_IN_libnss_nisplus
 690 # define libnss_nisplus_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 691 # define libnss_nisplus_hidden_def(name) hidden_def (name)
 692 # define libnss_nisplus_hidden_weak(name) hidden_weak (name)
 693 # define libnss_nisplus_hidden_ver(local, name) hidden_ver (local, name)
 694 # define libnss_nisplus_hidden_data_def(name) hidden_data_def (name)
 695 # define libnss_nisplus_hidden_data_weak(name) hidden_data_weak (name)
 696 # define libnss_nisplus_hidden_data_ver(local, name) hidden_data_ver (local, name)
 697 #else
 698 # define libnss_nisplus_hidden_proto(name, attrs...)
 699 # define libnss_nisplus_hidden_def(name)
 700 # define libnss_nisplus_hidden_weak(name)
 701 # define libnss_nisplus_hidden_ver(local, name)
 702 # define libnss_nisplus_hidden_data_def(name)
 703 # define libnss_nisplus_hidden_data_weak(name)
 704 # define libnss_nisplus_hidden_data_ver(local, name)
 705 #endif
 706
 707 #define libc_hidden_builtin_proto(name, attrs...) libc_hidden_proto (name, ##attrs)
 708 #define libc_hidden_builtin_def(name) libc_hidden_def (name)
 709 #define libc_hidden_builtin_weak(name) libc_hidden_weak (name)
 710 #define libc_hidden_builtin_ver(local, name) libc_hidden_ver (local, name)
 711 #ifdef __ASSEMBLER__
 712 # define HIDDEN_BUILTIN_JUMPTARGET(name) HIDDEN_JUMPTARGET(name)
 713 #endif
 714
 715 #if defined NOT_IN_libc && defined IS_IN_libutil
 716 # define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 717 # define libutil_hidden_def(name) hidden_def (name)
 718 # define libutil_hidden_weak(name) hidden_weak (name)
 719 # define libutil_hidden_ver(local, name) hidden_ver (local, name)
 720 # define libutil_hidden_data_def(name) hidden_data_def (name)
 721 # define libutil_hidden_data_weak(name) hidden_data_weak (name)
 722 # define libutil_hidden_data_ver(local, name) hidden_data_ver (local, name)
 723 #else
 724 # define libutil_hidden_proto(name, attrs...)
 725 # define libutil_hidden_def(name)
 726 # define libutil_hidden_weak(name)
 727 # define libutil_hidden_ver(local, name)
 728 # define libutil_hidden_data_def(name)
 729 # define libutil_hidden_data_weak(name)
 730 # define libutil_hidden_data_ver(local, name)
 731 #endif
 732
 733 /* Get some dirty hacks.  */
 734 #include <symbol-hacks.h>
 735
 736 /* Move compatibility symbols out of the way by placing them all in a
 737    special section.  */
 738 #ifndef __ASSEMBLER__
 739 # define attribute_compat_text_section \
 740     __attribute__ ((section (".text.compat")))
 741 # define attribute_compat_data_section \
 742     __attribute__ ((section (".data.compat")))
 743 #else
 744 # define compat_text_section .section ".text.compat", "ax";
 745 # define compat_data_section .section ".data.compat", "aw";
 746 #endif
 747
 748 /* Marker used for indirection function symbols.  */
 749 #define libc_ifunc(name, expr)                                          \
 750   extern void *name##_ifunc (void) __asm__ (#name);                     \
 751   void *name##_ifunc (void)                                             \
 752   {                                                                     \
 753     INIT_ARCH ();                                                       \
 754     __typeof (name) *res = expr;                                        \
 755     return res;                                                         \
 756   }                                                                     \
 757   __asm__ (".type " #name ", %gnu_indirect_function");
 758
 759 /* The body of the function is supposed to use __get_cpu_features
 760    which will, if necessary, initialize the data first.  */
 761 #define libm_ifunc(name, expr)                                          \
 762   extern void *name##_ifunc (void) __asm__ (#name);                     \
 763   void *name##_ifunc (void)                                             \
 764   {                                                                     \
 765     __typeof (name) *res = expr;                                        \
 766     return res;                                                         \
 767   }                                                                     \
 768   __asm__ (".type " #name ", %gnu_indirect_function");
 769
 770 #ifdef HAVE_ASM_SET_DIRECTIVE
 771 # define libc_ifunc_hidden_def1(local, name)                            \
 772     __asm__ (".globl " #local "\n\t"                                    \
 773              ".hidden " #local "\n\t"                                   \
 774              ".set " #local ", " #name);
 775 #else
 776 # define libc_ifunc_hidden_def1(local, name)                            \
 777     __asm__ (".globl " #local "\n\t"                                    \
 778              ".hidden " #local "\n\t"                                   \
 779              #local " = " #name);
 780 #endif
 781
 782 #define libc_ifunc_hidden_def(name) \
 783   libc_ifunc_hidden_def1 (__GI_##name, name)
 784
 785 /* Add the compiler optimization to inhibit loop transformation to library
 786    calls.  This is used to avoid recursive calls in memset and memmove
 787    default implementations.  */
 788 #ifdef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
 789 # define inhibit_loop_to_libcall \
 790     __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
 791 #else
 792 # define inhibit_loop_to_libcall
 793 #endif
 794
 795 #endif /* libc-symbols.h */