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) 1995-2014 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 #define IN_MODULE PASTE_NAME (MODULE_, MODULE_NAME)
  24 #define IS_IN(lib) (IN_MODULE == MODULE_##lib)
  25
  26 /* Returns true if the current module is a versioned library.  Versioned
  27    library names culled from shlib-versions files are assigned a MODULE_*
  28    value lower than MODULE_LIBS_BEGIN.  */
  29 #define IS_IN_LIB (IN_MODULE > MODULE_LIBS_BEGIN)
  30
  31 #define PASTE_NAME(a,b)      PASTE_NAME1 (a,b)
  32 #define PASTE_NAME1(a,b)     a##b
  33
  34 /* This file's macros are included implicitly in the compilation of every
  35    file in the C library by -imacros.
  36
  37    We include config.h which is generated by configure.
  38    It should define for us the following symbols:
  39
  40    * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'.
  41    * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'.
  42    * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'.
  43
  44    */
  45
  46 /* This is defined for the compilation of all C library code.  features.h
  47    tests this to avoid inclusion of stubs.h while compiling the library,
  48    before stubs.h has been generated.  Some library code that is shared
  49    with other packages also tests this symbol to see if it is being
  50    compiled as part of the C library.  We must define this before including
  51    config.h, because it makes some definitions conditional on whether libc
  52    itself is being compiled, or just some generator program.  */
  53 #define _LIBC   1
  54
  55 /* Enable declarations of GNU extensions, since we are compiling them.  */
  56 #define _GNU_SOURCE     1
  57 /* And we also need the data for the reentrant functions.  */
  58 #define _REENTRANT      1
  59
  60 #include <config.h>
  61
  62 /* Define this for the benefit of portable GNU code that wants to check it.
  63    Code that checks with #if will not #include <config.h> again, since we've
  64    already done it (and this file is implicitly included in every compile,
  65    via -include).  Code that checks with #ifdef will #include <config.h>,
  66    but that file should always be idempotent (i.e., it's just #define/#undef
  67    and nothing else anywhere should be changing the macro state it touches),
  68    so it's harmless.  */
  69 #define HAVE_CONFIG_H   0
  70
  71 /* Define these macros for the benefit of portable GNU code that wants to check
  72    them.  Of course, STDC_HEADERS is never false when building libc!  */
  73 #define STDC_HEADERS    1
  74 #define HAVE_MBSTATE_T  1
  75 #define HAVE_MBSRTOWCS  1
  76 #define HAVE_LIBINTL_H  1
  77 #define HAVE_WCTYPE_H   1
  78 #define HAVE_ISWCTYPE   1
  79 #define ENABLE_NLS      1
  80
  81 /* The symbols in all the user (non-_) macros are C symbols.  */
  82
  83 #if !defined HAVE_ASM_WEAK_DIRECTIVE && !defined HAVE_ASM_WEAKEXT_DIRECTIVE
  84 # error "weak symbol support needed"
  85 #endif
  86
  87 #ifndef __SYMBOL_PREFIX
  88 # define __SYMBOL_PREFIX
  89 #endif
  90
  91 #ifndef C_SYMBOL_NAME
  92 # define C_SYMBOL_NAME(name) name
  93 #endif
  94
  95 #ifndef ASM_LINE_SEP
  96 # define ASM_LINE_SEP ;
  97 #endif
  98
  99 #ifdef HAVE_ASM_GLOBAL_DOT_NAME
 100 # ifndef C_SYMBOL_DOT_NAME
 101 #  if defined __GNUC__ && defined __GNUC_MINOR__ \
 102       && (__GNUC__ << 16) + __GNUC_MINOR__ >= (3 << 16) + 1
 103 #   define C_SYMBOL_DOT_NAME(name) .name
 104 #  else
 105 #   define C_SYMBOL_DOT_NAME(name) .##name
 106 #  endif
 107 # endif
 108 #endif
 109
 110 #ifndef __ASSEMBLER__
 111 /* GCC understands weak symbols and aliases; use its interface where
 112    possible, instead of embedded assembly language.  */
 113
 114 /* Define ALIASNAME as a strong alias for NAME.  */
 115 # define strong_alias(name, aliasname) _strong_alias(name, aliasname)
 116 # define _strong_alias(name, aliasname) \
 117   extern __typeof (name) aliasname __attribute__ ((alias (#name)));
 118
 119 /* This comes between the return type and function name in
 120    a function definition to make that definition weak.  */
 121 # define weak_function __attribute__ ((weak))
 122 # define weak_const_function __attribute__ ((weak, __const__))
 123
 124 /* Define ALIASNAME as a weak alias for NAME.
 125    If weak aliases are not available, this defines a strong alias.  */
 126 # define weak_alias(name, aliasname) _weak_alias (name, aliasname)
 127 # define _weak_alias(name, aliasname) \
 128   extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
 129
 130 /* Same as WEAK_ALIAS, but mark symbol as hidden.  */
 131 # define weak_hidden_alias(name, aliasname) \
 132   _weak_hidden_alias (name, aliasname)
 133 # define _weak_hidden_alias(name, aliasname) \
 134   extern __typeof (name) aliasname \
 135     __attribute__ ((weak, alias (#name), __visibility__ ("hidden")));
 136
 137 /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined).  */
 138 # define weak_extern(symbol) _weak_extern (weak symbol)
 139 # define _weak_extern(expr) _Pragma (#expr)
 140
 141
 142 #else /* __ASSEMBLER__ */
 143
 144 # ifdef HAVE_ASM_SET_DIRECTIVE
 145 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 146 #   define strong_alias(original, alias)                                \
 147   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 148   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP      \
 149   .globl C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP         \
 150   .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original)
 151 #   define strong_data_alias(original, alias)                           \
 152   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 153   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 154 #  else
 155 #   define strong_alias(original, alias)                                \
 156   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 157   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 158 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 159 #  endif
 160 # else
 161 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 162 #   define strong_alias(original, alias)                                \
 163   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 164   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 165   .globl C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP         \
 166   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 167 #   define strong_data_alias(original, alias)                           \
 168   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 169   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 170 #  else
 171 #   define strong_alias(original, alias)                                \
 172   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 173   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 174 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 175 #  endif
 176 # endif
 177
 178 # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
 179 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 180 #   define weak_alias(original, alias)                                  \
 181   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \
 182   .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
 183 #  else
 184 #   define weak_alias(original, alias)                                  \
 185   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
 186 #  endif
 187 #  define weak_extern(symbol)                                           \
 188   .weakext C_SYMBOL_NAME (symbol)
 189
 190 # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 191
 192 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 193 #   define weak_alias(original, alias)                                  \
 194   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 195   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 196   .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP                          \
 197   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 198 #  else
 199 #   define weak_alias(original, alias)                                  \
 200   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 201   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 202 #  endif
 203
 204 #  define weak_extern(symbol)                                           \
 205   .weak C_SYMBOL_NAME (symbol)
 206
 207 # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 208
 209 #endif /* __ASSEMBLER__ */
 210
 211 /* On some platforms we can make internal function calls (i.e., calls of
 212    functions not exported) a bit faster by using a different calling
 213    convention.  */
 214 #ifndef internal_function
 215 # define internal_function      /* empty */
 216 #endif
 217
 218 /* Determine the return address.  */
 219 #define RETURN_ADDRESS(nr) \
 220   __builtin_extract_return_addr (__builtin_return_address (nr))
 221
 222 /* When a reference to SYMBOL is encountered, the linker will emit a
 223    warning message MSG.  */
 224 /* We want the .gnu.warning.SYMBOL section to be unallocated.  */
 225 #ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
 226 # define __make_section_unallocated(section_string)     \
 227   asm (".section " section_string "\n\t.previous");
 228 #elif defined HAVE_ASM_POPSECTION_DIRECTIVE
 229 # define __make_section_unallocated(section_string)     \
 230   asm (".pushsection " section_string "\n\t.popsection");
 231 #else
 232 # define __make_section_unallocated(section_string)
 233 #endif
 234
 235 /* Tacking on "\n\t#" to the section name makes gcc put it's bogus
 236    section attributes on what looks like a comment to the assembler.  */
 237 #ifdef HAVE_SECTION_QUOTES
 238 # define __sec_comment "\"\n\t#\""
 239 #else
 240 # define __sec_comment "\n\t#"
 241 #endif
 242 #define link_warning(symbol, msg) \
 243   __make_section_unallocated (".gnu.warning." #symbol) \
 244   static const char __evoke_link_warning_##symbol[]     \
 245     __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
 246     = msg;
 247 #define libc_freeres_ptr(decl) \
 248   __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
 249   decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
 250 #define __libc_freeres_fn_section \
 251   __attribute__ ((section ("__libc_freeres_fn")))
 252
 253 #define libc_freeres_fn(name)   \
 254   static void name (void) __attribute_used__ __libc_freeres_fn_section; \
 255   text_set_element (__libc_subfreeres, name);                           \
 256   static void name (void)
 257
 258 /* A canned warning for sysdeps/stub functions.  */
 259 #define stub_warning(name) \
 260   __make_section_unallocated (".gnu.glibc-stub." #name) \
 261   link_warning (name, #name " is not implemented and will always fail")
 262
 263 /* Warning for linking functions calling dlopen into static binaries.  */
 264 #ifdef SHARED
 265 #define static_link_warning(name)
 266 #else
 267 #define static_link_warning(name) static_link_warning1(name)
 268 #define static_link_warning1(name) \
 269   link_warning(name, "Using '" #name "' in statically linked applications \
 270 requires at runtime the shared libraries from the glibc version used \
 271 for linking")
 272 #endif
 273
 274 /* Declare SYMBOL to be TYPE (`function' or `object') of SIZE bytes
 275    alias to ORIGINAL, when the assembler supports such declarations
 276    (such as in ELF).
 277    This is only necessary when defining something in assembly, or playing
 278    funny alias games where the size should be other than what the compiler
 279    thinks it is.  */
 280 #define declare_symbol_alias(symbol, original, type, size) \
 281   declare_symbol_alias_1 (symbol, original, type, size)
 282 #ifdef __ASSEMBLER__
 283 # define declare_symbol_alias_1(symbol, original, type, size) \
 284    strong_alias (original, symbol); \
 285    .type C_SYMBOL_NAME (symbol), %##type; \
 286    .size C_SYMBOL_NAME (symbol), size
 287 #else /* Not __ASSEMBLER__.  */
 288 # define declare_symbol_alias_1(symbol, original, type, size) \
 289    asm (".globl " __SYMBOL_PREFIX #symbol \
 290         "\n\t" declare_symbol_alias_1_alias (symbol, original) \
 291         "\n\t.type " __SYMBOL_PREFIX #symbol ", " \
 292         "%" #type \
 293         "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size);
 294 # ifdef HAVE_ASM_SET_DIRECTIVE
 295 #  define declare_symbol_alias_1_alias(symbol, original) \
 296      ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX #original
 297 # else
 298 #  define declare_symbol_alias_1_alias(symbol, original) \
 299      __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX #original
 300 # endif /* HAVE_ASM_SET_DIRECTIVE */
 301 #endif /* __ASSEMBLER__ */
 302
 303
 304 /*
 305 \f
 306 */
 307
 308 /* Symbol set support macros.  */
 309
 310 /* Make SYMBOL, which is in the text segment, an element of SET.  */
 311 #define text_set_element(set, symbol)   _elf_set_element(set, symbol)
 312 /* Make SYMBOL, which is in the data segment, an element of SET.  */
 313 #define data_set_element(set, symbol)   _elf_set_element(set, symbol)
 314 /* Make SYMBOL, which is in the bss segment, an element of SET.  */
 315 #define bss_set_element(set, symbol)    _elf_set_element(set, symbol)
 316
 317 /* These are all done the same way in ELF.
 318    There is a new section created for each set.  */
 319 #ifdef SHARED
 320 /* When building a shared library, make the set section writable,
 321    because it will need to be relocated at run time anyway.  */
 322 # define _elf_set_element(set, symbol) \
 323   static const void *__elf_set_##set##_element_##symbol##__ \
 324     __attribute__ ((used, section (#set))) = &(symbol)
 325 #else
 326 # define _elf_set_element(set, symbol) \
 327   static const void *const __elf_set_##set##_element_##symbol##__ \
 328     __attribute__ ((used, section (#set))) = &(symbol)
 329 #endif
 330
 331 /* Define SET as a symbol set.  This may be required (it is in a.out) to
 332    be able to use the set's contents.  */
 333 #define symbol_set_define(set)  symbol_set_declare(set)
 334
 335 /* Declare SET for use in this module, if defined in another module.
 336    In a shared library, this is always local to that shared object.
 337    For static linking, the set might be wholly absent and so we use
 338    weak references.  */
 339 #define symbol_set_declare(set) \
 340   extern char const __start_##set[] __symbol_set_attribute; \
 341   extern char const __stop_##set[] __symbol_set_attribute;
 342 #ifdef SHARED
 343 # define __symbol_set_attribute attribute_hidden
 344 #else
 345 # define __symbol_set_attribute __attribute__ ((weak))
 346 #endif
 347
 348 /* Return a pointer (void *const *) to the first element of SET.  */
 349 #define symbol_set_first_element(set)   ((void *const *) (&__start_##set))
 350
 351 /* Return true iff PTR (a void *const *) has been incremented
 352    past the last element in SET.  */
 353 #define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
 354
 355 #ifdef SHARED
 356 # define symbol_version(real, name, version) \
 357      _symbol_version(real, name, version)
 358 # define default_symbol_version(real, name, version) \
 359      _default_symbol_version(real, name, version)
 360 # ifdef __ASSEMBLER__
 361 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 362 #   define _symbol_version(real, name, version) \
 363      .symver real, name##@##version ASM_LINE_SEP                        \
 364      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##version)
 365 #   define _default_symbol_version(real, name, version) \
 366      .symver real, name##@##@##version ASM_LINE_SEP                     \
 367      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##@##version)
 368 #  else
 369 #   define _symbol_version(real, name, version) \
 370      .symver real, name##@##version
 371 #   define _default_symbol_version(real, name, version) \
 372      .symver real, name##@##@##version
 373 #  endif
 374 # else
 375 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 376 #   define _symbol_version(real, name, version) \
 377      __asm__ (".symver " #real "," #name "@" #version "\n\t"    \
 378               ".symver ." #real ",." #name "@" #version)
 379 #   define _default_symbol_version(real, name, version) \
 380      __asm__ (".symver " #real "," #name "@@" #version "\n\t"   \
 381               ".symver ." #real ",." #name "@@" #version)
 382 #  else
 383 #   define _symbol_version(real, name, version) \
 384      __asm__ (".symver " #real "," #name "@" #version)
 385 #   define _default_symbol_version(real, name, version) \
 386      __asm__ (".symver " #real "," #name "@@" #version)
 387 #  endif
 388 # endif
 389 #else
 390 # define symbol_version(real, name, version)
 391 # define default_symbol_version(real, name, version) \
 392   strong_alias(real, name)
 393 #endif
 394
 395 #if defined SHARED || defined LIBC_NONSHARED
 396 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 397 #else
 398 # define attribute_hidden
 399 #endif
 400
 401 #define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
 402
 403 #define attribute_relro __attribute__ ((section (".data.rel.ro")))
 404
 405 /* The following macros are used for PLT bypassing within libc.so
 406    (and if needed other libraries similarly).
 407    First of all, you need to have the function prototyped somewhere,
 408    say in foo/foo.h:
 409
 410    int foo (int __bar);
 411
 412    If calls to foo within libc.so should always go to foo defined in libc.so,
 413    then in include/foo.h you add:
 414
 415    libc_hidden_proto (foo)
 416
 417    line and after the foo function definition:
 418
 419    int foo (int __bar)
 420    {
 421      return __bar;
 422    }
 423    libc_hidden_def (foo)
 424
 425    or
 426
 427    int foo (int __bar)
 428    {
 429      return __bar;
 430    }
 431    libc_hidden_weak (foo)
 432
 433    Similarly for global data.  If references to foo within libc.so should
 434    always go to foo defined in libc.so, then in include/foo.h you add:
 435
 436    libc_hidden_proto (foo)
 437
 438    line and after foo's definition:
 439
 440    int foo = INITIAL_FOO_VALUE;
 441    libc_hidden_data_def (foo)
 442
 443    or
 444
 445    int foo = INITIAL_FOO_VALUE;
 446    libc_hidden_data_weak (foo)
 447
 448    If foo is normally just an alias (strong or weak) to some other function,
 449    you should use the normal strong_alias first, then add libc_hidden_def
 450    or libc_hidden_weak:
 451
 452    int baz (int __bar)
 453    {
 454      return __bar;
 455    }
 456    strong_alias (baz, foo)
 457    libc_hidden_weak (foo)
 458
 459    If the function should be internal to multiple objects, say ld.so and
 460    libc.so, the best way is to use:
 461
 462    #if IS_IN (libc) || IS_IN (rtld)
 463    hidden_proto (foo)
 464    #endif
 465
 466    in include/foo.h and the normal macros at all function definitions
 467    depending on what DSO they belong to.
 468
 469    If versioned_symbol macro is used to define foo,
 470    libc_hidden_ver macro should be used, as in:
 471
 472    int __real_foo (int __bar)
 473    {
 474      return __bar;
 475    }
 476    versioned_symbol (libc, __real_foo, foo, GLIBC_2_1);
 477    libc_hidden_ver (__real_foo, foo)  */
 478
 479 #if defined SHARED && !defined NO_HIDDEN
 480 # ifndef __ASSEMBLER__
 481 #  define __hidden_proto_hiddenattr(attrs...) \
 482   __attribute__ ((visibility ("hidden"), ##attrs))
 483 #  define hidden_proto(name, attrs...) \
 484   __hidden_proto (name, , __GI_##name, ##attrs)
 485 #  define hidden_tls_proto(name, attrs...) \
 486   __hidden_proto (name, __thread, __GI_##name, ##attrs)
 487 #  define __hidden_proto(name, thread, internal, attrs...)           \
 488   extern thread __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
 489   __hidden_proto_hiddenattr (attrs);
 490 #  define __hidden_asmname(name) \
 491   __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
 492 #  define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
 493 #  define __hidden_asmname2(prefix, name) #prefix name
 494 #  define __hidden_ver1(local, internal, name) \
 495   extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
 496   extern __typeof (name) __EI_##name \
 497         __attribute__((alias (__hidden_asmname (#local))))
 498 #  define hidden_ver(local, name)       __hidden_ver1(local, __GI_##name, name);
 499 #  define hidden_data_ver(local, name)  hidden_ver(local, name)
 500 #  define hidden_def(name)              __hidden_ver1(__GI_##name, name, name);
 501 #  define hidden_data_def(name)         hidden_def(name)
 502 #  define hidden_weak(name) \
 503         __hidden_ver1(__GI_##name, name, name) __attribute__((weak));
 504 #  define hidden_data_weak(name)        hidden_weak(name)
 505 #  define hidden_nolink(name, lib, version) \
 506   __hidden_nolink1 (__GI_##name, __EI_##name, name, VERSION_##lib##_##version)
 507 #  define __hidden_nolink1(local, internal, name, version) \
 508   __hidden_nolink2 (local, internal, name, version)
 509 #  define __hidden_nolink2(local, internal, name, version) \
 510   extern __typeof (name) internal __attribute__ ((alias (#local))); \
 511   __hidden_nolink3 (local, internal, #name "@" #version)
 512 #  define __hidden_nolink3(local, internal, vername) \
 513   __asm__ (".symver " #internal ", " vername);
 514 # else
 515 /* For assembly, we need to do the opposite of what we do in C:
 516    in assembly gcc __REDIRECT stuff is not in place, so functions
 517    are defined by its normal name and we need to create the
 518    __GI_* alias to it, in C __REDIRECT causes the function definition
 519    to use __GI_* name and we need to add alias to the real name.
 520    There is no reason to use hidden_weak over hidden_def in assembly,
 521    but we provide it for consistency with the C usage.
 522    hidden_proto doesn't make sense for assembly but the equivalent
 523    is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET.  */
 524 #  define hidden_def(name)      strong_alias (name, __GI_##name)
 525 #  define hidden_weak(name)     hidden_def (name)
 526 #  define hidden_ver(local, name) strong_alias (local, __GI_##name)
 527 #  define hidden_data_def(name) strong_data_alias (name, __GI_##name)
 528 #  define hidden_data_weak(name)        hidden_data_def (name)
 529 #  define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
 530 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 531 #   define HIDDEN_JUMPTARGET(name) .__GI_##name
 532 #  else
 533 #   define HIDDEN_JUMPTARGET(name) __GI_##name
 534 #  endif
 535 # endif
 536 #else
 537 # ifndef __ASSEMBLER__
 538 #  define hidden_proto(name, attrs...)
 539 #  define hidden_tls_proto(name, attrs...)
 540 # else
 541 #  define HIDDEN_JUMPTARGET(name) JUMPTARGET(name)
 542 # endif /* Not  __ASSEMBLER__ */
 543 # define hidden_weak(name)
 544 # define hidden_def(name)
 545 # define hidden_ver(local, name)
 546 # define hidden_data_weak(name)
 547 # define hidden_data_def(name)
 548 # define hidden_data_ver(local, name)
 549 # define hidden_nolink(name, lib, version)
 550 #endif
 551
 552 #if IS_IN (libc)
 553 # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 554 # define libc_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 555 # define libc_hidden_def(name) hidden_def (name)
 556 # define libc_hidden_weak(name) hidden_weak (name)
 557 # ifdef LINK_OBSOLETE_RPC
 558    /* libc_hidden_nolink_sunrpc should only get used in sunrpc code.  */
 559 #  define libc_hidden_nolink_sunrpc(name, version) hidden_def (name)
 560 # else
 561 #  define libc_hidden_nolink_sunrpc(name, version) hidden_nolink (name, libc, version)
 562 # endif
 563 # define libc_hidden_ver(local, name) hidden_ver (local, name)
 564 # define libc_hidden_data_def(name) hidden_data_def (name)
 565 # define libc_hidden_data_weak(name) hidden_data_weak (name)
 566 # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
 567 #else
 568 # define libc_hidden_proto(name, attrs...)
 569 # define libc_hidden_tls_proto(name, attrs...)
 570 # define libc_hidden_def(name)
 571 # define libc_hidden_weak(name)
 572 # define libc_hidden_ver(local, name)
 573 # define libc_hidden_data_def(name)
 574 # define libc_hidden_data_weak(name)
 575 # define libc_hidden_data_ver(local, name)
 576 #endif
 577
 578 #if IS_IN (rtld)
 579 # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 580 # define rtld_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 581 # define rtld_hidden_def(name) hidden_def (name)
 582 # define rtld_hidden_weak(name) hidden_weak (name)
 583 # define rtld_hidden_ver(local, name) hidden_ver (local, name)
 584 # define rtld_hidden_data_def(name) hidden_data_def (name)
 585 # define rtld_hidden_data_weak(name) hidden_data_weak (name)
 586 # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name)
 587 #else
 588 # define rtld_hidden_proto(name, attrs...)
 589 # define rtld_hidden_tls_proto(name, attrs...)
 590 # define rtld_hidden_def(name)
 591 # define rtld_hidden_weak(name)
 592 # define rtld_hidden_ver(local, name)
 593 # define rtld_hidden_data_def(name)
 594 # define rtld_hidden_data_weak(name)
 595 # define rtld_hidden_data_ver(local, name)
 596 #endif
 597
 598 #if IS_IN (libm)
 599 # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 600 # define libm_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 601 # define libm_hidden_def(name) hidden_def (name)
 602 # define libm_hidden_weak(name) hidden_weak (name)
 603 # define libm_hidden_ver(local, name) hidden_ver (local, name)
 604 # define libm_hidden_data_def(name) hidden_data_def (name)
 605 # define libm_hidden_data_weak(name) hidden_data_weak (name)
 606 # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name)
 607 #else
 608 # define libm_hidden_proto(name, attrs...)
 609 # define libm_hidden_tls_proto(name, attrs...)
 610 # define libm_hidden_def(name)
 611 # define libm_hidden_weak(name)
 612 # define libm_hidden_ver(local, name)
 613 # define libm_hidden_data_def(name)
 614 # define libm_hidden_data_weak(name)
 615 # define libm_hidden_data_ver(local, name)
 616 #endif
 617
 618 #if IS_IN (libresolv)
 619 # define libresolv_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 620 # define libresolv_hidden_tls_proto(name, attrs...) \
 621   hidden_tls_proto (name, ##attrs)
 622 # define libresolv_hidden_def(name) hidden_def (name)
 623 # define libresolv_hidden_weak(name) hidden_weak (name)
 624 # define libresolv_hidden_ver(local, name) hidden_ver (local, name)
 625 # define libresolv_hidden_data_def(name) hidden_data_def (name)
 626 # define libresolv_hidden_data_weak(name) hidden_data_weak (name)
 627 # define libresolv_hidden_data_ver(local, name) hidden_data_ver (local, name)
 628 #else
 629 # define libresolv_hidden_proto(name, attrs...)
 630 # define libresolv_hidden_tls_proto(name, attrs...)
 631 # define libresolv_hidden_def(name)
 632 # define libresolv_hidden_weak(name)
 633 # define libresolv_hidden_ver(local, name)
 634 # define libresolv_hidden_data_def(name)
 635 # define libresolv_hidden_data_weak(name)
 636 # define libresolv_hidden_data_ver(local, name)
 637 #endif
 638
 639 #if IS_IN (librt)
 640 # define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 641 # define librt_hidden_tls_proto(name, attrs...) \
 642   hidden_tls_proto (name, ##attrs)
 643 # define librt_hidden_def(name) hidden_def (name)
 644 # define librt_hidden_weak(name) hidden_weak (name)
 645 # define librt_hidden_ver(local, name) hidden_ver (local, name)
 646 # define librt_hidden_data_def(name) hidden_data_def (name)
 647 # define librt_hidden_data_weak(name) hidden_data_weak (name)
 648 # define librt_hidden_data_ver(local, name) hidden_data_ver (local, name)
 649 #else
 650 # define librt_hidden_proto(name, attrs...)
 651 # define librt_hidden_tls_proto(name, attrs...)
 652 # define librt_hidden_def(name)
 653 # define librt_hidden_weak(name)
 654 # define librt_hidden_ver(local, name)
 655 # define librt_hidden_data_def(name)
 656 # define librt_hidden_data_weak(name)
 657 # define librt_hidden_data_ver(local, name)
 658 #endif
 659
 660 #if IS_IN (libdl)
 661 # define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 662 # define libdl_hidden_tls_proto(name, attrs...) \
 663   hidden_tls_proto (name, ##attrs)
 664 # define libdl_hidden_def(name) hidden_def (name)
 665 # define libdl_hidden_weak(name) hidden_weak (name)
 666 # define libdl_hidden_ver(local, name) hidden_ver (local, name)
 667 # define libdl_hidden_data_def(name) hidden_data_def (name)
 668 # define libdl_hidden_data_weak(name) hidden_data_weak (name)
 669 # define libdl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 670 #else
 671 # define libdl_hidden_proto(name, attrs...)
 672 # define libdl_hidden_tls_proto(name, attrs...)
 673 # define libdl_hidden_def(name)
 674 # define libdl_hidden_weak(name)
 675 # define libdl_hidden_ver(local, name)
 676 # define libdl_hidden_data_def(name)
 677 # define libdl_hidden_data_weak(name)
 678 # define libdl_hidden_data_ver(local, name)
 679 #endif
 680
 681 #if IS_IN (libnss_files)
 682 # define libnss_files_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 683 # define libnss_files_hidden_tls_proto(name, attrs...) \
 684   hidden_tls_proto (name, ##attrs)
 685 # define libnss_files_hidden_def(name) hidden_def (name)
 686 # define libnss_files_hidden_weak(name) hidden_weak (name)
 687 # define libnss_files_hidden_ver(local, name) hidden_ver (local, name)
 688 # define libnss_files_hidden_data_def(name) hidden_data_def (name)
 689 # define libnss_files_hidden_data_weak(name) hidden_data_weak (name)
 690 # define libnss_files_hidden_data_ver(local, name) hidden_data_ver(local, name)
 691 #else
 692 # define libnss_files_hidden_proto(name, attrs...)
 693 # define libnss_files_hidden_tls_proto(name, attrs...)
 694 # define libnss_files_hidden_def(name)
 695 # define libnss_files_hidden_weak(name)
 696 # define libnss_files_hidden_ver(local, name)
 697 # define libnss_files_hidden_data_def(name)
 698 # define libnss_files_hidden_data_weak(name)
 699 # define libnss_files_hidden_data_ver(local, name)
 700 #endif
 701
 702 #if IS_IN (libnsl)
 703 # define libnsl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 704 # define libnsl_hidden_tls_proto(name, attrs...) \
 705   hidden_tls_proto (name, ##attrs)
 706 # define libnsl_hidden_def(name) hidden_def (name)
 707 # define libnsl_hidden_weak(name) hidden_weak (name)
 708 # define libnsl_hidden_ver(local, name) hidden_ver (local, name)
 709 # define libnsl_hidden_data_def(name) hidden_data_def (name)
 710 # define libnsl_hidden_data_weak(name) hidden_data_weak (name)
 711 # define libnsl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 712 #else
 713 # define libnsl_hidden_proto(name, attrs...)
 714 # define libnsl_hidden_tls_proto(name, attrs...)
 715 # define libnsl_hidden_def(name)
 716 # define libnsl_hidden_weak(name)
 717 # define libnsl_hidden_ver(local, name)
 718 # define libnsl_hidden_data_def(name)
 719 # define libnsl_hidden_data_weak(name)
 720 # define libnsl_hidden_data_ver(local, name)
 721 #endif
 722
 723 #if IS_IN (libnss_nisplus)
 724 # define libnss_nisplus_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 725 # define libnss_nisplus_hidden_tls_proto(name, attrs...) \
 726   hidden_tls_proto (name, ##attrs)
 727 # define libnss_nisplus_hidden_def(name) hidden_def (name)
 728 # define libnss_nisplus_hidden_weak(name) hidden_weak (name)
 729 # define libnss_nisplus_hidden_ver(local, name) hidden_ver (local, name)
 730 # define libnss_nisplus_hidden_data_def(name) hidden_data_def (name)
 731 # define libnss_nisplus_hidden_data_weak(name) hidden_data_weak (name)
 732 # define libnss_nisplus_hidden_data_ver(local, name) hidden_data_ver (local, name)
 733 #else
 734 # define libnss_nisplus_hidden_proto(name, attrs...)
 735 # define libnss_nisplus_hidden_tls_proto(name, attrs...)
 736 # define libnss_nisplus_hidden_def(name)
 737 # define libnss_nisplus_hidden_weak(name)
 738 # define libnss_nisplus_hidden_ver(local, name)
 739 # define libnss_nisplus_hidden_data_def(name)
 740 # define libnss_nisplus_hidden_data_weak(name)
 741 # define libnss_nisplus_hidden_data_ver(local, name)
 742 #endif
 743
 744 #define libc_hidden_builtin_proto(name, attrs...) libc_hidden_proto (name, ##attrs)
 745 #define libc_hidden_builtin_def(name) libc_hidden_def (name)
 746 #define libc_hidden_builtin_weak(name) libc_hidden_weak (name)
 747 #define libc_hidden_builtin_ver(local, name) libc_hidden_ver (local, name)
 748 #ifdef __ASSEMBLER__
 749 # define HIDDEN_BUILTIN_JUMPTARGET(name) HIDDEN_JUMPTARGET(name)
 750 #endif
 751
 752 #if IS_IN (libutil)
 753 # define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 754 # define libutil_hidden_tls_proto(name, attrs...) \
 755   hidden_tls_proto (name, ##attrs)
 756 # define libutil_hidden_def(name) hidden_def (name)
 757 # define libutil_hidden_weak(name) hidden_weak (name)
 758 # define libutil_hidden_ver(local, name) hidden_ver (local, name)
 759 # define libutil_hidden_data_def(name) hidden_data_def (name)
 760 # define libutil_hidden_data_weak(name) hidden_data_weak (name)
 761 # define libutil_hidden_data_ver(local, name) hidden_data_ver (local, name)
 762 #else
 763 # define libutil_hidden_proto(name, attrs...)
 764 # define libutil_hidden_tls_proto(name, attrs...)
 765 # define libutil_hidden_def(name)
 766 # define libutil_hidden_weak(name)
 767 # define libutil_hidden_ver(local, name)
 768 # define libutil_hidden_data_def(name)
 769 # define libutil_hidden_data_weak(name)
 770 # define libutil_hidden_data_ver(local, name)
 771 #endif
 772
 773 /* Get some dirty hacks.  */
 774 #include <symbol-hacks.h>
 775
 776 /* Move compatibility symbols out of the way by placing them all in a
 777    special section.  */
 778 #ifndef __ASSEMBLER__
 779 # define attribute_compat_text_section \
 780     __attribute__ ((section (".text.compat")))
 781 # define attribute_compat_data_section \
 782     __attribute__ ((section (".data.compat")))
 783 #else
 784 # define compat_text_section .section ".text.compat", "ax";
 785 # define compat_data_section .section ".data.compat", "aw";
 786 #endif
 787
 788 /* Marker used for indirection function symbols.  */
 789 #define libc_ifunc(name, expr)                                          \
 790   extern void *name##_ifunc (void) __asm__ (#name);                     \
 791   void *name##_ifunc (void)                                             \
 792   {                                                                     \
 793     INIT_ARCH ();                                                       \
 794     __typeof (name) *res = expr;                                        \
 795     return res;                                                         \
 796   }                                                                     \
 797   __asm__ (".type " #name ", %gnu_indirect_function");
 798
 799 /* The body of the function is supposed to use __get_cpu_features
 800    which will, if necessary, initialize the data first.  */
 801 #define libm_ifunc(name, expr)                                          \
 802   extern void *name##_ifunc (void) __asm__ (#name);                     \
 803   void *name##_ifunc (void)                                             \
 804   {                                                                     \
 805     __typeof (name) *res = expr;                                        \
 806     return res;                                                         \
 807   }                                                                     \
 808   __asm__ (".type " #name ", %gnu_indirect_function");
 809
 810 #ifdef HAVE_ASM_SET_DIRECTIVE
 811 # define libc_ifunc_hidden_def1(local, name)                            \
 812     __asm__ (".globl " #local "\n\t"                                    \
 813              ".hidden " #local "\n\t"                                   \
 814              ".set " #local ", " #name);
 815 #else
 816 # define libc_ifunc_hidden_def1(local, name)                            \
 817     __asm__ (".globl " #local "\n\t"                                    \
 818              ".hidden " #local "\n\t"                                   \
 819              #local " = " #name);
 820 #endif
 821
 822 #define libc_ifunc_hidden_def(name) \
 823   libc_ifunc_hidden_def1 (__GI_##name, name)
 824
 825 /* Add the compiler optimization to inhibit loop transformation to library
 826    calls.  This is used to avoid recursive calls in memset and memmove
 827    default implementations.  */
 828 #ifdef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
 829 # define inhibit_loop_to_libcall \
 830     __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
 831 #else
 832 # define inhibit_loop_to_libcall
 833 #endif
 834
 835 #endif /* libc-symbols.h */