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) 1995-1998,2000-2006,2008,2009,2011,2012
   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, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef _LIBC_SYMBOLS_H
  22 #define _LIBC_SYMBOLS_H 1
  23
  24 /* This file's macros are included implicitly in the compilation of every
  25    file in the C library by -imacros.
  26
  27    We include config.h which is generated by configure.
  28    It should define for us the following symbols:
  29
  30    * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'.
  31    * ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'.
  32    * ASM_TYPE_DIRECTIVE_PREFIX with `@' or `#' or whatever for .type,
  33      or leave it undefined if there is no .type directive.
  34    * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'.
  35    * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'.
  36
  37    */
  38
  39 /* This is defined for the compilation of all C library code.  features.h
  40    tests this to avoid inclusion of stubs.h while compiling the library,
  41    before stubs.h has been generated.  Some library code that is shared
  42    with other packages also tests this symbol to see if it is being
  43    compiled as part of the C library.  We must define this before including
  44    config.h, because it makes some definitions conditional on whether libc
  45    itself is being compiled, or just some generator program.  */
  46 #define _LIBC   1
  47
  48 /* Enable declarations of GNU extensions, since we are compiling them.  */
  49 #define _GNU_SOURCE     1
  50 /* And we also need the data for the reentrant functions.  */
  51 #define _REENTRANT      1
  52
  53 #include <config.h>
  54
  55 /* The symbols in all the user (non-_) macros are C symbols.  */
  56
  57 #if !defined HAVE_ASM_WEAK_DIRECTIVE && !defined HAVE_ASM_WEAKEXT_DIRECTIVE
  58 # error "weak symbol support needed"
  59 #endif
  60
  61 #ifndef __SYMBOL_PREFIX
  62 # define __SYMBOL_PREFIX
  63 #endif
  64
  65 #ifndef C_SYMBOL_NAME
  66 # define C_SYMBOL_NAME(name) name
  67 #endif
  68
  69 #ifndef ASM_LINE_SEP
  70 # define ASM_LINE_SEP ;
  71 #endif
  72
  73 #ifdef HAVE_ASM_GLOBAL_DOT_NAME
  74 # ifndef C_SYMBOL_DOT_NAME
  75 #  if defined __GNUC__ && defined __GNUC_MINOR__ \
  76       && (__GNUC__ << 16) + __GNUC_MINOR__ >= (3 << 16) + 1
  77 #   define C_SYMBOL_DOT_NAME(name) .name
  78 #  else
  79 #   define C_SYMBOL_DOT_NAME(name) .##name
  80 #  endif
  81 # endif
  82 #endif
  83
  84 #ifndef __ASSEMBLER__
  85 /* GCC understands weak symbols and aliases; use its interface where
  86    possible, instead of embedded assembly language.  */
  87
  88 /* Define ALIASNAME as a strong alias for NAME.  */
  89 # define strong_alias(name, aliasname) _strong_alias(name, aliasname)
  90 # define _strong_alias(name, aliasname) \
  91   extern __typeof (name) aliasname __attribute__ ((alias (#name)));
  92
  93 /* This comes between the return type and function name in
  94    a function definition to make that definition weak.  */
  95 # define weak_function __attribute__ ((weak))
  96 # define weak_const_function __attribute__ ((weak, __const__))
  97
  98 /* Define ALIASNAME as a weak alias for NAME.
  99    If weak aliases are not available, this defines a strong alias.  */
 100 # define weak_alias(name, aliasname) _weak_alias (name, aliasname)
 101 # define _weak_alias(name, aliasname) \
 102   extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
 103
 104 /* Same as WEAK_ALIAS, but mark symbol as hidden.  */
 105 # define weak_hidden_alias(name, aliasname) \
 106   _weak_hidden_alias (name, aliasname)
 107 # define _weak_hidden_alias(name, aliasname) \
 108   extern __typeof (name) aliasname \
 109     __attribute__ ((weak, alias (#name), __visibility__ ("hidden")));
 110
 111 /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined).  */
 112 # define weak_extern(symbol) _weak_extern (weak symbol)
 113 # define _weak_extern(expr) _Pragma (#expr)
 114
 115
 116 #else /* __ASSEMBLER__ */
 117
 118 # ifdef HAVE_ASM_SET_DIRECTIVE
 119 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 120 #   define strong_alias(original, alias)                                \
 121   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 122   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP      \
 123   ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP           \
 124   .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original)
 125 #   define strong_data_alias(original, alias)                           \
 126   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 127   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 128 #  else
 129 #   define strong_alias(original, alias)                                \
 130   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 131   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 132 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 133 #  endif
 134 # else
 135 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 136 #   define strong_alias(original, alias)                                \
 137   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 138   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 139   ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP           \
 140   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 141 #   define strong_data_alias(original, alias)                           \
 142   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 143   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 144 #  else
 145 #   define strong_alias(original, alias)                                \
 146   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP               \
 147   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 148 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 149 #  endif
 150 # endif
 151
 152 # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
 153 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 154 #   define weak_alias(original, alias)                                  \
 155   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \
 156   .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
 157 #  else
 158 #   define weak_alias(original, alias)                                  \
 159   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
 160 #  endif
 161 #  define weak_extern(symbol)                                           \
 162   .weakext C_SYMBOL_NAME (symbol)
 163
 164 # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 165
 166 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 167 #   define weak_alias(original, alias)                                  \
 168   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 169   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 170   .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP                          \
 171   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 172 #  else
 173 #   define weak_alias(original, alias)                                  \
 174   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 175   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 176 #  endif
 177
 178 #  define weak_extern(symbol)                                           \
 179   .weak C_SYMBOL_NAME (symbol)
 180
 181 # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 182
 183 #endif /* __ASSEMBLER__ */
 184
 185 /* On some platforms we can make internal function calls (i.e., calls of
 186    functions not exported) a bit faster by using a different calling
 187    convention.  */
 188 #ifndef internal_function
 189 # define internal_function      /* empty */
 190 #endif
 191
 192 /* Determine the return address.  */
 193 #define RETURN_ADDRESS(nr) \
 194   __builtin_extract_return_addr (__builtin_return_address (nr))
 195
 196 /* When a reference to SYMBOL is encountered, the linker will emit a
 197    warning message MSG.  */
 198 /* We want the .gnu.warning.SYMBOL section to be unallocated.  */
 199 #ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
 200 # define __make_section_unallocated(section_string)     \
 201   asm (".section " section_string "\n\t.previous");
 202 #elif defined HAVE_ASM_POPSECTION_DIRECTIVE
 203 # define __make_section_unallocated(section_string)     \
 204   asm (".pushsection " section_string "\n\t.popsection");
 205 #else
 206 # define __make_section_unallocated(section_string)
 207 #endif
 208
 209 /* Tacking on "\n\t#" to the section name makes gcc put it's bogus
 210    section attributes on what looks like a comment to the assembler.  */
 211 #ifdef HAVE_SECTION_QUOTES
 212 # define __sec_comment "\"\n\t#\""
 213 #else
 214 # define __sec_comment "\n\t#"
 215 #endif
 216 #define link_warning(symbol, msg) \
 217   __make_section_unallocated (".gnu.warning." #symbol) \
 218   static const char __evoke_link_warning_##symbol[]     \
 219     __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
 220     = msg;
 221 #define libc_freeres_ptr(decl) \
 222   __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
 223   decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
 224 #define __libc_freeres_fn_section \
 225   __attribute__ ((section ("__libc_freeres_fn")))
 226
 227 #define libc_freeres_fn(name)   \
 228   static void name (void) __attribute_used__ __libc_freeres_fn_section; \
 229   text_set_element (__libc_subfreeres, name);                           \
 230   static void name (void)
 231
 232 /* A canned warning for sysdeps/stub functions.  */
 233 #define stub_warning(name) \
 234   __make_section_unallocated (".gnu.glibc-stub." #name) \
 235   link_warning (name, \
 236                 "warning: " #name " is not implemented and will always fail")
 237
 238 /* Warning for linking functions calling dlopen into static binaries.  */
 239 #ifdef SHARED
 240 #define static_link_warning(name)
 241 #else
 242 #define static_link_warning(name) static_link_warning1(name)
 243 #define static_link_warning1(name) \
 244   link_warning(name, "Using '" #name "' in statically linked applications \
 245 requires at runtime the shared libraries from the glibc version used \
 246 for linking")
 247 #endif
 248
 249 /* Declare SYMBOL to be TYPE (`function' or `object') of SIZE bytes
 250    alias to ORIGINAL, when the assembler supports such declarations
 251    (such as in ELF).
 252    This is only necessary when defining something in assembly, or playing
 253    funny alias games where the size should be other than what the compiler
 254    thinks it is.  */
 255 #define declare_symbol_alias(symbol, original, type, size) \
 256   declare_symbol_alias_1 (symbol, original, type, size)
 257 #ifdef ASM_TYPE_DIRECTIVE_PREFIX
 258 # ifdef __ASSEMBLER__
 259 #  define declare_symbol_alias_1(symbol, original, type, size) \
 260     strong_alias (original, symbol); \
 261     .type C_SYMBOL_NAME (symbol), \
 262           declare_symbol_alias_1_paste (ASM_TYPE_DIRECTIVE_PREFIX, type); \
 263     .size C_SYMBOL_NAME (symbol), size
 264 #  define declare_symbol_alias_1_paste(a, b) \
 265   declare_symbol_alias_1_paste_1 (a,b)
 266 #  define declare_symbol_alias_1_paste_1(a,b)   a##b
 267 # else /* Not __ASSEMBLER__.  */
 268 #  define declare_symbol_alias_1(symbol, original, type, size) \
 269     asm (declare_symbol_alias_1_stringify (ASM_GLOBAL_DIRECTIVE) \
 270          " " __SYMBOL_PREFIX #symbol \
 271          "\n\t" declare_symbol_alias_1_alias (symbol, original) \
 272          "\n\t.type " __SYMBOL_PREFIX #symbol ", " \
 273          declare_symbol_alias_1_stringify (ASM_TYPE_DIRECTIVE_PREFIX) #type \
 274          "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size);
 275 #  define declare_symbol_alias_1_stringify(x) \
 276   declare_symbol_alias_1_stringify_1 (x)
 277 #  define declare_symbol_alias_1_stringify_1(x) #x
 278 #  ifdef HAVE_ASM_SET_DIRECTIVE
 279 #   define declare_symbol_alias_1_alias(symbol, original) \
 280          ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX #original
 281 #  else
 282 #   define declare_symbol_alias_1_alias(symbol, original) \
 283          __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX #original
 284 #  endif /* HAVE_ASM_SET_DIRECTIVE */
 285 # endif /* __ASSEMBLER__ */
 286 #else
 287 # define declare_symbol_1(symbol, type, size) /* Nothing.  */
 288 #endif
 289
 290
 291 /*
 292 \f
 293 */
 294
 295 /* Symbol set support macros.  */
 296
 297 /* Make SYMBOL, which is in the text segment, an element of SET.  */
 298 #define text_set_element(set, symbol)   _elf_set_element(set, symbol)
 299 /* Make SYMBOL, which is in the data segment, an element of SET.  */
 300 #define data_set_element(set, symbol)   _elf_set_element(set, symbol)
 301 /* Make SYMBOL, which is in the bss segment, an element of SET.  */
 302 #define bss_set_element(set, symbol)    _elf_set_element(set, symbol)
 303
 304 /* These are all done the same way in ELF.
 305    There is a new section created for each set.  */
 306 #ifdef SHARED
 307 /* When building a shared library, make the set section writable,
 308    because it will need to be relocated at run time anyway.  */
 309 # define _elf_set_element(set, symbol) \
 310   static const void *__elf_set_##set##_element_##symbol##__ \
 311     __attribute__ ((used, section (#set))) = &(symbol)
 312 #else
 313 # define _elf_set_element(set, symbol) \
 314   static const void *const __elf_set_##set##_element_##symbol##__ \
 315     __attribute__ ((used, section (#set))) = &(symbol)
 316 #endif
 317
 318 /* Define SET as a symbol set.  This may be required (it is in a.out) to
 319    be able to use the set's contents.  */
 320 #define symbol_set_define(set)  symbol_set_declare(set)
 321
 322 /* Declare SET for use in this module, if defined in another module.
 323    In a shared library, this is always local to that shared object.
 324    For static linking, the set might be wholly absent and so we use
 325    weak references.  */
 326 #define symbol_set_declare(set) \
 327   extern char const __start_##set[] __symbol_set_attribute; \
 328   extern char const __stop_##set[] __symbol_set_attribute;
 329 #ifdef SHARED
 330 # define __symbol_set_attribute attribute_hidden
 331 #else
 332 # define __symbol_set_attribute __attribute__ ((weak))
 333 #endif
 334
 335 /* Return a pointer (void *const *) to the first element of SET.  */
 336 #define symbol_set_first_element(set)   ((void *const *) (&__start_##set))
 337
 338 /* Return true iff PTR (a void *const *) has been incremented
 339    past the last element in SET.  */
 340 #define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
 341
 342 #if DO_VERSIONING
 343 # define symbol_version(real, name, version) \
 344      _symbol_version(real, name, version)
 345 # define default_symbol_version(real, name, version) \
 346      _default_symbol_version(real, name, version)
 347 # ifdef __ASSEMBLER__
 348 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 349 #   define _symbol_version(real, name, version) \
 350      .symver real, name##@##version ASM_LINE_SEP                        \
 351      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##version)
 352 #   define _default_symbol_version(real, name, version) \
 353      .symver real, name##@##@##version ASM_LINE_SEP                     \
 354      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##@##version)
 355 #  else
 356 #   define _symbol_version(real, name, version) \
 357      .symver real, name##@##version
 358 #   define _default_symbol_version(real, name, version) \
 359      .symver real, name##@##@##version
 360 #  endif
 361 # else
 362 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 363 #   define _symbol_version(real, name, version) \
 364      __asm__ (".symver " #real "," #name "@" #version "\n\t"    \
 365               ".symver ." #real ",." #name "@" #version)
 366 #   define _default_symbol_version(real, name, version) \
 367      __asm__ (".symver " #real "," #name "@@" #version "\n\t"   \
 368               ".symver ." #real ",." #name "@@" #version)
 369 #  else
 370 #   define _symbol_version(real, name, version) \
 371      __asm__ (".symver " #real "," #name "@" #version)
 372 #   define _default_symbol_version(real, name, version) \
 373      __asm__ (".symver " #real "," #name "@@" #version)
 374 #  endif
 375 # endif
 376 #else
 377 # define symbol_version(real, name, version)
 378 # define default_symbol_version(real, name, version) \
 379   strong_alias(real, name)
 380 #endif
 381
 382 #if defined SHARED || defined LIBC_NONSHARED
 383 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 384 #else
 385 # define attribute_hidden
 386 #endif
 387
 388 #define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
 389
 390 #define attribute_relro __attribute__ ((section (".data.rel.ro")))
 391
 392 /* Handling on non-exported internal names.  We have to do this only
 393    for shared code.  */
 394 #ifdef SHARED
 395 # define INTUSE(name) name##_internal
 396 # define INTDEF(name) strong_alias (name, name##_internal)
 397 # define INTVARDEF(name) \
 398   _INTVARDEF (name, name##_internal)
 399 # define _INTVARDEF(name, aliasname) \
 400   extern __typeof (name) aliasname __attribute__ ((alias (#name), \
 401                                                    visibility ("hidden")));
 402 # define INTDEF2(name, newname) strong_alias (name, newname##_internal)
 403 # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal)
 404 #else
 405 # define INTUSE(name) name
 406 # define INTDEF(name)
 407 # define INTVARDEF(name)
 408 # define INTDEF2(name, newname)
 409 # define INTVARDEF2(name, newname)
 410 #endif
 411
 412 /* The following macros are used for PLT bypassing within libc.so
 413    (and if needed other libraries similarly).
 414    First of all, you need to have the function prototyped somewhere,
 415    say in foo/foo.h:
 416
 417    int foo (int __bar);
 418
 419    If calls to foo within libc.so should always go to foo defined in libc.so,
 420    then in include/foo.h you add:
 421
 422    libc_hidden_proto (foo)
 423
 424    line and after the foo function definition:
 425
 426    int foo (int __bar)
 427    {
 428      return __bar;
 429    }
 430    libc_hidden_def (foo)
 431
 432    or
 433
 434    int foo (int __bar)
 435    {
 436      return __bar;
 437    }
 438    libc_hidden_weak (foo)
 439
 440    Similarly for global data.  If references to foo within libc.so should
 441    always go to foo defined in libc.so, then in include/foo.h you add:
 442
 443    libc_hidden_proto (foo)
 444
 445    line and after foo's definition:
 446
 447    int foo = INITIAL_FOO_VALUE;
 448    libc_hidden_data_def (foo)
 449
 450    or
 451
 452    int foo = INITIAL_FOO_VALUE;
 453    libc_hidden_data_weak (foo)
 454
 455    If foo is normally just an alias (strong or weak) to some other function,
 456    you should use the normal strong_alias first, then add libc_hidden_def
 457    or libc_hidden_weak:
 458
 459    int baz (int __bar)
 460    {
 461      return __bar;
 462    }
 463    strong_alias (baz, foo)
 464    libc_hidden_weak (foo)
 465
 466    If the function should be internal to multiple objects, say ld.so and
 467    libc.so, the best way is to use:
 468
 469    #if !defined NOT_IN_libc || defined IS_IN_rtld
 470    hidden_proto (foo)
 471    #endif
 472
 473    in include/foo.h and the normal macros at all function definitions
 474    depending on what DSO they belong to.
 475
 476    If versioned_symbol macro is used to define foo,
 477    libc_hidden_ver macro should be used, as in:
 478
 479    int __real_foo (int __bar)
 480    {
 481      return __bar;
 482    }
 483    versioned_symbol (libc, __real_foo, foo, GLIBC_2_1);
 484    libc_hidden_ver (__real_foo, foo)  */
 485
 486 #if defined SHARED && defined DO_VERSIONING && !defined NO_HIDDEN
 487 # ifndef __ASSEMBLER__
 488 #  define __hidden_proto_hiddenattr(attrs...) \
 489   __attribute__ ((visibility ("hidden"), ##attrs))
 490 #  define hidden_proto(name, attrs...) \
 491   __hidden_proto (name, __GI_##name, ##attrs)
 492 #  define __hidden_proto(name, internal, attrs...) \
 493   extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
 494   __hidden_proto_hiddenattr (attrs);
 495 #  define __hidden_asmname(name) \
 496   __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
 497 #  define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
 498 #  define __hidden_asmname2(prefix, name) #prefix name
 499 #  define __hidden_ver1(local, internal, name) \
 500   extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
 501   extern __typeof (name) __EI_##name \
 502         __attribute__((alias (__hidden_asmname (#local))))
 503 #  define hidden_ver(local, name)       __hidden_ver1(local, __GI_##name, name);
 504 #  define hidden_data_ver(local, name)  hidden_ver(local, name)
 505 #  define hidden_def(name)              __hidden_ver1(__GI_##name, name, name);
 506 #  define hidden_data_def(name)         hidden_def(name)
 507 #  define hidden_weak(name) \
 508         __hidden_ver1(__GI_##name, name, name) __attribute__((weak));
 509 #  define hidden_data_weak(name)        hidden_weak(name)
 510 #  define hidden_nolink(name, lib, version) \
 511   __hidden_nolink1 (__GI_##name, __EI_##name, name, VERSION_##lib##_##version)
 512 #  define __hidden_nolink1(local, internal, name, version) \
 513   __hidden_nolink2 (local, internal, name, version)
 514 #  define __hidden_nolink2(local, internal, name, version) \
 515   extern __typeof (name) internal __attribute__ ((alias (#local))); \
 516   __hidden_nolink3 (local, internal, #name "@" #version)
 517 #  define __hidden_nolink3(local, internal, vername) \
 518   __asm__ (".symver " #internal ", " vername);
 519 # else
 520 /* For assembly, we need to do the opposite of what we do in C:
 521    in assembly gcc __REDIRECT stuff is not in place, so functions
 522    are defined by its normal name and we need to create the
 523    __GI_* alias to it, in C __REDIRECT causes the function definition
 524    to use __GI_* name and we need to add alias to the real name.
 525    There is no reason to use hidden_weak over hidden_def in assembly,
 526    but we provide it for consistency with the C usage.
 527    hidden_proto doesn't make sense for assembly but the equivalent
 528    is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET.  */
 529 #  define hidden_def(name)      strong_alias (name, __GI_##name)
 530 #  define hidden_weak(name)     hidden_def (name)
 531 #  define hidden_ver(local, name) strong_alias (local, __GI_##name)
 532 #  define hidden_data_def(name) strong_data_alias (name, __GI_##name)
 533 #  define hidden_data_weak(name)        hidden_data_def (name)
 534 #  define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
 535 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 536 #   define HIDDEN_JUMPTARGET(name) .__GI_##name
 537 #  else
 538 #   define HIDDEN_JUMPTARGET(name) __GI_##name
 539 #  endif
 540 # endif
 541 #else
 542 # ifndef __ASSEMBLER__
 543 #  define hidden_proto(name, attrs...)
 544 # else
 545 #  define HIDDEN_JUMPTARGET(name) JUMPTARGET(name)
 546 # endif /* Not  __ASSEMBLER__ */
 547 # define hidden_weak(name)
 548 # define hidden_def(name)
 549 # define hidden_ver(local, name)
 550 # define hidden_data_weak(name)
 551 # define hidden_data_def(name)
 552 # define hidden_data_ver(local, name)
 553 #endif
 554
 555 #if !defined NOT_IN_libc
 556 # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 557 # define libc_hidden_def(name) hidden_def (name)
 558 # define libc_hidden_weak(name) hidden_weak (name)
 559 # define libc_hidden_nolink(name, version) hidden_nolink (name, libc, version)
 560 # define libc_hidden_ver(local, name) hidden_ver (local, name)
 561 # define libc_hidden_data_def(name) hidden_data_def (name)
 562 # define libc_hidden_data_weak(name) hidden_data_weak (name)
 563 # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
 564 #else
 565 # define libc_hidden_proto(name, attrs...)
 566 # define libc_hidden_def(name)
 567 # define libc_hidden_weak(name)
 568 # define libc_hidden_ver(local, name)
 569 # define libc_hidden_data_def(name)
 570 # define libc_hidden_data_weak(name)
 571 # define libc_hidden_data_ver(local, name)
 572 #endif
 573
 574 #if defined NOT_IN_libc && defined IS_IN_rtld
 575 # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 576 # define rtld_hidden_def(name) hidden_def (name)
 577 # define rtld_hidden_weak(name) hidden_weak (name)
 578 # define rtld_hidden_ver(local, name) hidden_ver (local, name)
 579 # define rtld_hidden_data_def(name) hidden_data_def (name)
 580 # define rtld_hidden_data_weak(name) hidden_data_weak (name)
 581 # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name)
 582 #else
 583 # define rtld_hidden_proto(name, attrs...)
 584 # define rtld_hidden_def(name)
 585 # define rtld_hidden_weak(name)
 586 # define rtld_hidden_ver(local, name)
 587 # define rtld_hidden_data_def(name)
 588 # define rtld_hidden_data_weak(name)
 589 # define rtld_hidden_data_ver(local, name)
 590 #endif
 591
 592 #if defined NOT_IN_libc && defined IS_IN_libm
 593 # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 594 # define libm_hidden_def(name) hidden_def (name)
 595 # define libm_hidden_weak(name) hidden_weak (name)
 596 # define libm_hidden_ver(local, name) hidden_ver (local, name)
 597 # define libm_hidden_data_def(name) hidden_data_def (name)
 598 # define libm_hidden_data_weak(name) hidden_data_weak (name)
 599 # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name)
 600 #else
 601 # define libm_hidden_proto(name, attrs...)
 602 # define libm_hidden_def(name)
 603 # define libm_hidden_weak(name)
 604 # define libm_hidden_ver(local, name)
 605 # define libm_hidden_data_def(name)
 606 # define libm_hidden_data_weak(name)
 607 # define libm_hidden_data_ver(local, name)
 608 #endif
 609
 610 #if defined NOT_IN_libc && defined IS_IN_libresolv
 611 # define libresolv_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 612 # define libresolv_hidden_def(name) hidden_def (name)
 613 # define libresolv_hidden_weak(name) hidden_weak (name)
 614 # define libresolv_hidden_ver(local, name) hidden_ver (local, name)
 615 # define libresolv_hidden_data_def(name) hidden_data_def (name)
 616 # define libresolv_hidden_data_weak(name) hidden_data_weak (name)
 617 # define libresolv_hidden_data_ver(local, name) hidden_data_ver (local, name)
 618 #else
 619 # define libresolv_hidden_proto(name, attrs...)
 620 # define libresolv_hidden_def(name)
 621 # define libresolv_hidden_weak(name)
 622 # define libresolv_hidden_ver(local, name)
 623 # define libresolv_hidden_data_def(name)
 624 # define libresolv_hidden_data_weak(name)
 625 # define libresolv_hidden_data_ver(local, name)
 626 #endif
 627
 628 #if defined NOT_IN_libc && defined IS_IN_librt
 629 # define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 630 # define librt_hidden_def(name) hidden_def (name)
 631 # define librt_hidden_weak(name) hidden_weak (name)
 632 # define librt_hidden_ver(local, name) hidden_ver (local, name)
 633 # define librt_hidden_data_def(name) hidden_data_def (name)
 634 # define librt_hidden_data_weak(name) hidden_data_weak (name)
 635 # define librt_hidden_data_ver(local, name) hidden_data_ver (local, name)
 636 #else
 637 # define librt_hidden_proto(name, attrs...)
 638 # define librt_hidden_def(name)
 639 # define librt_hidden_weak(name)
 640 # define librt_hidden_ver(local, name)
 641 # define librt_hidden_data_def(name)
 642 # define librt_hidden_data_weak(name)
 643 # define librt_hidden_data_ver(local, name)
 644 #endif
 645
 646 #if defined NOT_IN_libc && defined IS_IN_libdl
 647 # define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 648 # define libdl_hidden_def(name) hidden_def (name)
 649 # define libdl_hidden_weak(name) hidden_weak (name)
 650 # define libdl_hidden_ver(local, name) hidden_ver (local, name)
 651 # define libdl_hidden_data_def(name) hidden_data_def (name)
 652 # define libdl_hidden_data_weak(name) hidden_data_weak (name)
 653 # define libdl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 654 #else
 655 # define libdl_hidden_proto(name, attrs...)
 656 # define libdl_hidden_def(name)
 657 # define libdl_hidden_weak(name)
 658 # define libdl_hidden_ver(local, name)
 659 # define libdl_hidden_data_def(name)
 660 # define libdl_hidden_data_weak(name)
 661 # define libdl_hidden_data_ver(local, name)
 662 #endif
 663
 664 #if defined NOT_IN_libc && defined IS_IN_libnss_files
 665 # define libnss_files_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 666 # define libnss_files_hidden_def(name) hidden_def (name)
 667 # define libnss_files_hidden_weak(name) hidden_weak (name)
 668 # define libnss_files_hidden_ver(local, name) hidden_ver (local, name)
 669 # define libnss_files_hidden_data_def(name) hidden_data_def (name)
 670 # define libnss_files_hidden_data_weak(name) hidden_data_weak (name)
 671 # define libnss_files_hidden_data_ver(local, name) hidden_data_ver(local, name)
 672 #else
 673 # define libnss_files_hidden_proto(name, attrs...)
 674 # define libnss_files_hidden_def(name)
 675 # define libnss_files_hidden_weak(name)
 676 # define libnss_files_hidden_ver(local, name)
 677 # define libnss_files_hidden_data_def(name)
 678 # define libnss_files_hidden_data_weak(name)
 679 # define libnss_files_hidden_data_ver(local, name)
 680 #endif
 681
 682 #if defined NOT_IN_libc && defined IS_IN_libnsl
 683 # define libnsl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 684 # define libnsl_hidden_def(name) hidden_def (name)
 685 # define libnsl_hidden_weak(name) hidden_weak (name)
 686 # define libnsl_hidden_ver(local, name) hidden_ver (local, name)
 687 # define libnsl_hidden_data_def(name) hidden_data_def (name)
 688 # define libnsl_hidden_data_weak(name) hidden_data_weak (name)
 689 # define libnsl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 690 #else
 691 # define libnsl_hidden_proto(name, attrs...)
 692 # define libnsl_hidden_def(name)
 693 # define libnsl_hidden_weak(name)
 694 # define libnsl_hidden_ver(local, name)
 695 # define libnsl_hidden_data_def(name)
 696 # define libnsl_hidden_data_weak(name)
 697 # define libnsl_hidden_data_ver(local, name)
 698 #endif
 699
 700 #if defined NOT_IN_libc && defined IS_IN_libnss_nisplus
 701 # define libnss_nisplus_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 702 # define libnss_nisplus_hidden_def(name) hidden_def (name)
 703 # define libnss_nisplus_hidden_weak(name) hidden_weak (name)
 704 # define libnss_nisplus_hidden_ver(local, name) hidden_ver (local, name)
 705 # define libnss_nisplus_hidden_data_def(name) hidden_data_def (name)
 706 # define libnss_nisplus_hidden_data_weak(name) hidden_data_weak (name)
 707 # define libnss_nisplus_hidden_data_ver(local, name) hidden_data_ver (local, name)
 708 #else
 709 # define libnss_nisplus_hidden_proto(name, attrs...)
 710 # define libnss_nisplus_hidden_def(name)
 711 # define libnss_nisplus_hidden_weak(name)
 712 # define libnss_nisplus_hidden_ver(local, name)
 713 # define libnss_nisplus_hidden_data_def(name)
 714 # define libnss_nisplus_hidden_data_weak(name)
 715 # define libnss_nisplus_hidden_data_ver(local, name)
 716 #endif
 717
 718 #define libc_hidden_builtin_proto(name, attrs...) libc_hidden_proto (name, ##attrs)
 719 #define libc_hidden_builtin_def(name) libc_hidden_def (name)
 720 #define libc_hidden_builtin_weak(name) libc_hidden_weak (name)
 721 #define libc_hidden_builtin_ver(local, name) libc_hidden_ver (local, name)
 722 #ifdef __ASSEMBLER__
 723 # define HIDDEN_BUILTIN_JUMPTARGET(name) HIDDEN_JUMPTARGET(name)
 724 #endif
 725
 726 #if defined NOT_IN_libc && defined IS_IN_libutil
 727 # define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 728 # define libutil_hidden_def(name) hidden_def (name)
 729 # define libutil_hidden_weak(name) hidden_weak (name)
 730 # define libutil_hidden_ver(local, name) hidden_ver (local, name)
 731 # define libutil_hidden_data_def(name) hidden_data_def (name)
 732 # define libutil_hidden_data_weak(name) hidden_data_weak (name)
 733 # define libutil_hidden_data_ver(local, name) hidden_data_ver (local, name)
 734 #else
 735 # define libutil_hidden_proto(name, attrs...)
 736 # define libutil_hidden_def(name)
 737 # define libutil_hidden_weak(name)
 738 # define libutil_hidden_ver(local, name)
 739 # define libutil_hidden_data_def(name)
 740 # define libutil_hidden_data_weak(name)
 741 # define libutil_hidden_data_ver(local, name)
 742 #endif
 743
 744 /* Get some dirty hacks.  */
 745 #include <symbol-hacks.h>
 746
 747 /* Move compatibility symbols out of the way by placing them all in a
 748    special section.  */
 749 #ifndef __ASSEMBLER__
 750 # define attribute_compat_text_section \
 751     __attribute__ ((section (".text.compat")))
 752 # define attribute_compat_data_section \
 753     __attribute__ ((section (".data.compat")))
 754 #else
 755 # define compat_text_section .section ".text.compat", "ax";
 756 # define compat_data_section .section ".data.compat", "aw";
 757 #endif
 758
 759 /* Marker used for indirection function symbols.  */
 760 #define libc_ifunc(name, expr)                                          \
 761   extern void *name##_ifunc (void) __asm__ (#name);                     \
 762   void *name##_ifunc (void)                                             \
 763   {                                                                     \
 764     INIT_ARCH ();                                                       \
 765     __typeof (name) *res = expr;                                        \
 766     return res;                                                         \
 767   }                                                                     \
 768   __asm__ (".type " #name ", %gnu_indirect_function");
 769
 770 /* The body of the function is supposed to use __get_cpu_features
 771    which will, if necessary, initialize the data first.  */
 772 #define libm_ifunc(name, expr)                                          \
 773   extern void *name##_ifunc (void) __asm__ (#name);                     \
 774   void *name##_ifunc (void)                                             \
 775   {                                                                     \
 776     __typeof (name) *res = expr;                                        \
 777     return res;                                                         \
 778   }                                                                     \
 779   __asm__ (".type " #name ", %gnu_indirect_function");
 780
 781 #ifdef HAVE_ASM_SET_DIRECTIVE
 782 # define libc_ifunc_hidden_def1(local, name)                            \
 783     __asm__ (declare_symbol_alias_1_stringify (ASM_GLOBAL_DIRECTIVE)    \
 784              " " #local "\n\t"                                          \
 785              ".hidden " #local "\n\t"                                   \
 786              ".set " #local ", " #name);
 787 #else
 788 # define libc_ifunc_hidden_def1(local, name)                            \
 789     __asm__ (declare_symbol_alias_1_stringify (ASM_GLOBAL_DIRECTIVE)    \
 790              " " #local "\n\t"                                          \
 791              ".hidden " #local "\n\t"                                   \
 792              #local " = " #name);
 793 #endif
 794
 795 #define libc_ifunc_hidden_def(name) \
 796   libc_ifunc_hidden_def1 (__GI_##name, name)
 797
 798 #endif /* libc-symbols.h */