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 /* 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 /* Define this for the benefit of portable GNU code that wants to check it.
  52    Code that checks with #if will not #include <config.h> again, since we've
  53    already done it (and this file is implicitly included in every compile,
  54    via -include).  Code that checks with #ifdef will #include <config.h>,
  55    but that file should always be idempotent (i.e., it's just #define/#undef
  56    and nothing else anywhere should be changing the macro state it touches),
  57    so it's harmless.  */
  58 #define HAVE_CONFIG_H   0
  59
  60 /* Define these macros for the benefit of portable GNU code that wants to check
  61    them.  Of course, STDC_HEADERS is never false when building libc!  */
  62 #define STDC_HEADERS    1
  63 #define HAVE_MBSTATE_T  1
  64 #define HAVE_MBSRTOWCS  1
  65 #define HAVE_LIBINTL_H  1
  66 #define HAVE_WCTYPE_H   1
  67 #define HAVE_ISWCTYPE   1
  68 #define ENABLE_NLS      1
  69
  70 /* The symbols in all the user (non-_) macros are C symbols.  */
  71
  72 #if !defined HAVE_ASM_WEAK_DIRECTIVE && !defined HAVE_ASM_WEAKEXT_DIRECTIVE
  73 # error "weak symbol support needed"
  74 #endif
  75
  76 #ifndef __SYMBOL_PREFIX
  77 # define __SYMBOL_PREFIX
  78 #endif
  79
  80 #ifndef C_SYMBOL_NAME
  81 # define C_SYMBOL_NAME(name) name
  82 #endif
  83
  84 #ifndef ASM_LINE_SEP
  85 # define ASM_LINE_SEP ;
  86 #endif
  87
  88 #ifdef HAVE_ASM_GLOBAL_DOT_NAME
  89 # ifndef C_SYMBOL_DOT_NAME
  90 #  if defined __GNUC__ && defined __GNUC_MINOR__ \
  91       && (__GNUC__ << 16) + __GNUC_MINOR__ >= (3 << 16) + 1
  92 #   define C_SYMBOL_DOT_NAME(name) .name
  93 #  else
  94 #   define C_SYMBOL_DOT_NAME(name) .##name
  95 #  endif
  96 # endif
  97 #endif
  98
  99 #ifndef __ASSEMBLER__
 100 /* GCC understands weak symbols and aliases; use its interface where
 101    possible, instead of embedded assembly language.  */
 102
 103 /* Define ALIASNAME as a strong alias for NAME.  */
 104 # define strong_alias(name, aliasname) _strong_alias(name, aliasname)
 105 # define _strong_alias(name, aliasname) \
 106   extern __typeof (name) aliasname __attribute__ ((alias (#name)));
 107
 108 /* This comes between the return type and function name in
 109    a function definition to make that definition weak.  */
 110 # define weak_function __attribute__ ((weak))
 111 # define weak_const_function __attribute__ ((weak, __const__))
 112
 113 /* Define ALIASNAME as a weak alias for NAME.
 114    If weak aliases are not available, this defines a strong alias.  */
 115 # define weak_alias(name, aliasname) _weak_alias (name, aliasname)
 116 # define _weak_alias(name, aliasname) \
 117   extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
 118
 119 /* Same as WEAK_ALIAS, but mark symbol as hidden.  */
 120 # define weak_hidden_alias(name, aliasname) \
 121   _weak_hidden_alias (name, aliasname)
 122 # define _weak_hidden_alias(name, aliasname) \
 123   extern __typeof (name) aliasname \
 124     __attribute__ ((weak, alias (#name), __visibility__ ("hidden")));
 125
 126 /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined).  */
 127 # define weak_extern(symbol) _weak_extern (weak symbol)
 128 # define _weak_extern(expr) _Pragma (#expr)
 129
 130
 131 #else /* __ASSEMBLER__ */
 132
 133 # ifdef HAVE_ASM_SET_DIRECTIVE
 134 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 135 #   define strong_alias(original, alias)                                \
 136   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 137   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP      \
 138   .globl C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP         \
 139   .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original)
 140 #   define strong_data_alias(original, alias)                           \
 141   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 142   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 143 #  else
 144 #   define strong_alias(original, alias)                                \
 145   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 146   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 147 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 148 #  endif
 149 # else
 150 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 151 #   define strong_alias(original, alias)                                \
 152   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 153   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 154   .globl C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP         \
 155   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 156 #   define strong_data_alias(original, alias)                           \
 157   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 158   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 159 #  else
 160 #   define strong_alias(original, alias)                                \
 161   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 162   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 163 #   define strong_data_alias(original, alias) strong_alias(original, alias)
 164 #  endif
 165 # endif
 166
 167 # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
 168 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 169 #   define weak_alias(original, alias)                                  \
 170   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \
 171   .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
 172 #  else
 173 #   define weak_alias(original, alias)                                  \
 174   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
 175 #  endif
 176 #  define weak_extern(symbol)                                           \
 177   .weakext C_SYMBOL_NAME (symbol)
 178
 179 # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 180
 181 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 182 #   define weak_alias(original, alias)                                  \
 183   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 184   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP         \
 185   .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP                          \
 186   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 187 #  else
 188 #   define weak_alias(original, alias)                                  \
 189   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 190   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 191 #  endif
 192
 193 #  define weak_extern(symbol)                                           \
 194   .weak C_SYMBOL_NAME (symbol)
 195
 196 # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 197
 198 #endif /* __ASSEMBLER__ */
 199
 200 /* On some platforms we can make internal function calls (i.e., calls of
 201    functions not exported) a bit faster by using a different calling
 202    convention.  */
 203 #ifndef internal_function
 204 # define internal_function      /* empty */
 205 #endif
 206
 207 /* Determine the return address.  */
 208 #define RETURN_ADDRESS(nr) \
 209   __builtin_extract_return_addr (__builtin_return_address (nr))
 210
 211 /* When a reference to SYMBOL is encountered, the linker will emit a
 212    warning message MSG.  */
 213 /* We want the .gnu.warning.SYMBOL section to be unallocated.  */
 214 #ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
 215 # define __make_section_unallocated(section_string)     \
 216   asm (".section " section_string "\n\t.previous");
 217 #elif defined HAVE_ASM_POPSECTION_DIRECTIVE
 218 # define __make_section_unallocated(section_string)     \
 219   asm (".pushsection " section_string "\n\t.popsection");
 220 #else
 221 # define __make_section_unallocated(section_string)
 222 #endif
 223
 224 /* Tacking on "\n\t#" to the section name makes gcc put it's bogus
 225    section attributes on what looks like a comment to the assembler.  */
 226 #ifdef HAVE_SECTION_QUOTES
 227 # define __sec_comment "\"\n\t#\""
 228 #else
 229 # define __sec_comment "\n\t#"
 230 #endif
 231 #define link_warning(symbol, msg) \
 232   __make_section_unallocated (".gnu.warning." #symbol) \
 233   static const char __evoke_link_warning_##symbol[]     \
 234     __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
 235     = msg;
 236 #define libc_freeres_ptr(decl) \
 237   __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
 238   decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
 239 #define __libc_freeres_fn_section \
 240   __attribute__ ((section ("__libc_freeres_fn")))
 241
 242 #define libc_freeres_fn(name)   \
 243   static void name (void) __attribute_used__ __libc_freeres_fn_section; \
 244   text_set_element (__libc_subfreeres, name);                           \
 245   static void name (void)
 246
 247 /* A canned warning for sysdeps/stub functions.  */
 248 #define stub_warning(name) \
 249   __make_section_unallocated (".gnu.glibc-stub." #name) \
 250   link_warning (name, #name " is not implemented and will always fail")
 251
 252 /* Warning for linking functions calling dlopen into static binaries.  */
 253 #ifdef SHARED
 254 #define static_link_warning(name)
 255 #else
 256 #define static_link_warning(name) static_link_warning1(name)
 257 #define static_link_warning1(name) \
 258   link_warning(name, "Using '" #name "' in statically linked applications \
 259 requires at runtime the shared libraries from the glibc version used \
 260 for linking")
 261 #endif
 262
 263 /* Declare SYMBOL to be TYPE (`function' or `object') of SIZE bytes
 264    alias to ORIGINAL, when the assembler supports such declarations
 265    (such as in ELF).
 266    This is only necessary when defining something in assembly, or playing
 267    funny alias games where the size should be other than what the compiler
 268    thinks it is.  */
 269 #define declare_symbol_alias(symbol, original, type, size) \
 270   declare_symbol_alias_1 (symbol, original, type, size)
 271 #ifdef __ASSEMBLER__
 272 # define declare_symbol_alias_1(symbol, original, type, size) \
 273    strong_alias (original, symbol); \
 274    .type C_SYMBOL_NAME (symbol), %##type; \
 275    .size C_SYMBOL_NAME (symbol), size
 276 #else /* Not __ASSEMBLER__.  */
 277 # define declare_symbol_alias_1(symbol, original, type, size) \
 278    asm (".globl " __SYMBOL_PREFIX #symbol \
 279         "\n\t" declare_symbol_alias_1_alias (symbol, original) \
 280         "\n\t.type " __SYMBOL_PREFIX #symbol ", " \
 281         "%" #type \
 282         "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size);
 283 # ifdef HAVE_ASM_SET_DIRECTIVE
 284 #  define declare_symbol_alias_1_alias(symbol, original) \
 285      ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX #original
 286 # else
 287 #  define declare_symbol_alias_1_alias(symbol, original) \
 288      __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX #original
 289 # endif /* HAVE_ASM_SET_DIRECTIVE */
 290 #endif /* __ASSEMBLER__ */
 291
 292
 293 /*
 294 \f
 295 */
 296
 297 /* Symbol set support macros.  */
 298
 299 /* Make SYMBOL, which is in the text segment, an element of SET.  */
 300 #define text_set_element(set, symbol)   _elf_set_element(set, symbol)
 301 /* Make SYMBOL, which is in the data segment, an element of SET.  */
 302 #define data_set_element(set, symbol)   _elf_set_element(set, symbol)
 303 /* Make SYMBOL, which is in the bss segment, an element of SET.  */
 304 #define bss_set_element(set, symbol)    _elf_set_element(set, symbol)
 305
 306 /* These are all done the same way in ELF.
 307    There is a new section created for each set.  */
 308 #ifdef SHARED
 309 /* When building a shared library, make the set section writable,
 310    because it will need to be relocated at run time anyway.  */
 311 # define _elf_set_element(set, symbol) \
 312   static const void *__elf_set_##set##_element_##symbol##__ \
 313     __attribute__ ((used, section (#set))) = &(symbol)
 314 #else
 315 # define _elf_set_element(set, symbol) \
 316   static const void *const __elf_set_##set##_element_##symbol##__ \
 317     __attribute__ ((used, section (#set))) = &(symbol)
 318 #endif
 319
 320 /* Define SET as a symbol set.  This may be required (it is in a.out) to
 321    be able to use the set's contents.  */
 322 #define symbol_set_define(set)  symbol_set_declare(set)
 323
 324 /* Declare SET for use in this module, if defined in another module.
 325    In a shared library, this is always local to that shared object.
 326    For static linking, the set might be wholly absent and so we use
 327    weak references.  */
 328 #define symbol_set_declare(set) \
 329   extern char const __start_##set[] __symbol_set_attribute; \
 330   extern char const __stop_##set[] __symbol_set_attribute;
 331 #ifdef SHARED
 332 # define __symbol_set_attribute attribute_hidden
 333 #else
 334 # define __symbol_set_attribute __attribute__ ((weak))
 335 #endif
 336
 337 /* Return a pointer (void *const *) to the first element of SET.  */
 338 #define symbol_set_first_element(set)   ((void *const *) (&__start_##set))
 339
 340 /* Return true iff PTR (a void *const *) has been incremented
 341    past the last element in SET.  */
 342 #define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
 343
 344 #ifdef SHARED
 345 # define symbol_version(real, name, version) \
 346      _symbol_version(real, name, version)
 347 # define default_symbol_version(real, name, version) \
 348      _default_symbol_version(real, name, version)
 349 # ifdef __ASSEMBLER__
 350 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 351 #   define _symbol_version(real, name, version) \
 352      .symver real, name##@##version ASM_LINE_SEP                        \
 353      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##version)
 354 #   define _default_symbol_version(real, name, version) \
 355      .symver real, name##@##@##version ASM_LINE_SEP                     \
 356      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##@##version)
 357 #  else
 358 #   define _symbol_version(real, name, version) \
 359      .symver real, name##@##version
 360 #   define _default_symbol_version(real, name, version) \
 361      .symver real, name##@##@##version
 362 #  endif
 363 # else
 364 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 365 #   define _symbol_version(real, name, version) \
 366      __asm__ (".symver " #real "," #name "@" #version "\n\t"    \
 367               ".symver ." #real ",." #name "@" #version)
 368 #   define _default_symbol_version(real, name, version) \
 369      __asm__ (".symver " #real "," #name "@@" #version "\n\t"   \
 370               ".symver ." #real ",." #name "@@" #version)
 371 #  else
 372 #   define _symbol_version(real, name, version) \
 373      __asm__ (".symver " #real "," #name "@" #version)
 374 #   define _default_symbol_version(real, name, version) \
 375      __asm__ (".symver " #real "," #name "@@" #version)
 376 #  endif
 377 # endif
 378 #else
 379 # define symbol_version(real, name, version)
 380 # define default_symbol_version(real, name, version) \
 381   strong_alias(real, name)
 382 #endif
 383
 384 #if defined SHARED || defined LIBC_NONSHARED
 385 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 386 #else
 387 # define attribute_hidden
 388 #endif
 389
 390 #define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
 391
 392 #define attribute_relro __attribute__ ((section (".data.rel.ro")))
 393
 394 /* Handling on non-exported internal names.  We have to do this only
 395    for shared code.  */
 396 #ifdef SHARED
 397 # define INTUSE(name) name##_internal
 398 # define INTDEF(name) strong_alias (name, name##_internal)
 399 # define INTVARDEF(name) \
 400   _INTVARDEF (name, name##_internal)
 401 # define _INTVARDEF(name, aliasname) \
 402   extern __typeof (name) aliasname __attribute__ ((alias (#name), \
 403                                                    visibility ("hidden")));
 404 # define INTDEF2(name, newname) strong_alias (name, newname##_internal)
 405 # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal)
 406 #else
 407 # define INTUSE(name) name
 408 # define INTDEF(name)
 409 # define INTVARDEF(name)
 410 # define INTDEF2(name, newname)
 411 # define INTVARDEF2(name, newname)
 412 #endif
 413
 414 /* The following macros are used for PLT bypassing within libc.so
 415    (and if needed other libraries similarly).
 416    First of all, you need to have the function prototyped somewhere,
 417    say in foo/foo.h:
 418
 419    int foo (int __bar);
 420
 421    If calls to foo within libc.so should always go to foo defined in libc.so,
 422    then in include/foo.h you add:
 423
 424    libc_hidden_proto (foo)
 425
 426    line and after the foo function definition:
 427
 428    int foo (int __bar)
 429    {
 430      return __bar;
 431    }
 432    libc_hidden_def (foo)
 433
 434    or
 435
 436    int foo (int __bar)
 437    {
 438      return __bar;
 439    }
 440    libc_hidden_weak (foo)
 441
 442    Similarly for global data.  If references to foo within libc.so should
 443    always go to foo defined in libc.so, then in include/foo.h you add:
 444
 445    libc_hidden_proto (foo)
 446
 447    line and after foo's definition:
 448
 449    int foo = INITIAL_FOO_VALUE;
 450    libc_hidden_data_def (foo)
 451
 452    or
 453
 454    int foo = INITIAL_FOO_VALUE;
 455    libc_hidden_data_weak (foo)
 456
 457    If foo is normally just an alias (strong or weak) to some other function,
 458    you should use the normal strong_alias first, then add libc_hidden_def
 459    or libc_hidden_weak:
 460
 461    int baz (int __bar)
 462    {
 463      return __bar;
 464    }
 465    strong_alias (baz, foo)
 466    libc_hidden_weak (foo)
 467
 468    If the function should be internal to multiple objects, say ld.so and
 469    libc.so, the best way is to use:
 470
 471    #if !defined NOT_IN_libc || defined IS_IN_rtld
 472    hidden_proto (foo)
 473    #endif
 474
 475    in include/foo.h and the normal macros at all function definitions
 476    depending on what DSO they belong to.
 477
 478    If versioned_symbol macro is used to define foo,
 479    libc_hidden_ver macro should be used, as in:
 480
 481    int __real_foo (int __bar)
 482    {
 483      return __bar;
 484    }
 485    versioned_symbol (libc, __real_foo, foo, GLIBC_2_1);
 486    libc_hidden_ver (__real_foo, foo)  */
 487
 488 #if defined SHARED && !defined NO_HIDDEN
 489 # ifndef __ASSEMBLER__
 490 #  define __hidden_proto_hiddenattr(attrs...) \
 491   __attribute__ ((visibility ("hidden"), ##attrs))
 492 #  define hidden_proto(name, attrs...) \
 493   __hidden_proto (name, , __GI_##name, ##attrs)
 494 #  define hidden_tls_proto(name, attrs...) \
 495   __hidden_proto (name, __thread, __GI_##name, ##attrs)
 496 #  define __hidden_proto(name, thread, internal, attrs...)           \
 497   extern thread __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
 498   __hidden_proto_hiddenattr (attrs);
 499 #  define __hidden_asmname(name) \
 500   __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
 501 #  define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
 502 #  define __hidden_asmname2(prefix, name) #prefix name
 503 #  define __hidden_ver1(local, internal, name) \
 504   extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
 505   extern __typeof (name) __EI_##name \
 506         __attribute__((alias (__hidden_asmname (#local))))
 507 #  define hidden_ver(local, name)       __hidden_ver1(local, __GI_##name, name);
 508 #  define hidden_data_ver(local, name)  hidden_ver(local, name)
 509 #  define hidden_def(name)              __hidden_ver1(__GI_##name, name, name);
 510 #  define hidden_data_def(name)         hidden_def(name)
 511 #  define hidden_weak(name) \
 512         __hidden_ver1(__GI_##name, name, name) __attribute__((weak));
 513 #  define hidden_data_weak(name)        hidden_weak(name)
 514 #  define hidden_nolink(name, lib, version) \
 515   __hidden_nolink1 (__GI_##name, __EI_##name, name, VERSION_##lib##_##version)
 516 #  define __hidden_nolink1(local, internal, name, version) \
 517   __hidden_nolink2 (local, internal, name, version)
 518 #  define __hidden_nolink2(local, internal, name, version) \
 519   extern __typeof (name) internal __attribute__ ((alias (#local))); \
 520   __hidden_nolink3 (local, internal, #name "@" #version)
 521 #  define __hidden_nolink3(local, internal, vername) \
 522   __asm__ (".symver " #internal ", " vername);
 523 # else
 524 /* For assembly, we need to do the opposite of what we do in C:
 525    in assembly gcc __REDIRECT stuff is not in place, so functions
 526    are defined by its normal name and we need to create the
 527    __GI_* alias to it, in C __REDIRECT causes the function definition
 528    to use __GI_* name and we need to add alias to the real name.
 529    There is no reason to use hidden_weak over hidden_def in assembly,
 530    but we provide it for consistency with the C usage.
 531    hidden_proto doesn't make sense for assembly but the equivalent
 532    is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET.  */
 533 #  define hidden_def(name)      strong_alias (name, __GI_##name)
 534 #  define hidden_weak(name)     hidden_def (name)
 535 #  define hidden_ver(local, name) strong_alias (local, __GI_##name)
 536 #  define hidden_data_def(name) strong_data_alias (name, __GI_##name)
 537 #  define hidden_data_weak(name)        hidden_data_def (name)
 538 #  define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
 539 #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 540 #   define HIDDEN_JUMPTARGET(name) .__GI_##name
 541 #  else
 542 #   define HIDDEN_JUMPTARGET(name) __GI_##name
 543 #  endif
 544 # endif
 545 #else
 546 # ifndef __ASSEMBLER__
 547 #  define hidden_proto(name, attrs...)
 548 #  define hidden_tls_proto(name, attrs...)
 549 # else
 550 #  define HIDDEN_JUMPTARGET(name) JUMPTARGET(name)
 551 # endif /* Not  __ASSEMBLER__ */
 552 # define hidden_weak(name)
 553 # define hidden_def(name)
 554 # define hidden_ver(local, name)
 555 # define hidden_data_weak(name)
 556 # define hidden_data_def(name)
 557 # define hidden_data_ver(local, name)
 558 # define hidden_nolink(name, lib, version)
 559 #endif
 560
 561 #if !defined NOT_IN_libc
 562 # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 563 # define libc_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 564 # define libc_hidden_def(name) hidden_def (name)
 565 # define libc_hidden_weak(name) hidden_weak (name)
 566 # ifdef LINK_OBSOLETE_RPC
 567    /* libc_hidden_nolink_sunrpc should only get used in sunrpc code.  */
 568 #  define libc_hidden_nolink_sunrpc(name, version) hidden_def (name)
 569 # else
 570 #  define libc_hidden_nolink_sunrpc(name, version) hidden_nolink (name, libc, version)
 571 # endif
 572 # define libc_hidden_ver(local, name) hidden_ver (local, name)
 573 # define libc_hidden_data_def(name) hidden_data_def (name)
 574 # define libc_hidden_data_weak(name) hidden_data_weak (name)
 575 # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
 576 #else
 577 # define libc_hidden_proto(name, attrs...)
 578 # define libc_hidden_tls_proto(name, attrs...)
 579 # define libc_hidden_def(name)
 580 # define libc_hidden_weak(name)
 581 # define libc_hidden_ver(local, name)
 582 # define libc_hidden_data_def(name)
 583 # define libc_hidden_data_weak(name)
 584 # define libc_hidden_data_ver(local, name)
 585 #endif
 586
 587 #ifdef IS_IN_rtld
 588 # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 589 # define rtld_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 590 # define rtld_hidden_def(name) hidden_def (name)
 591 # define rtld_hidden_weak(name) hidden_weak (name)
 592 # define rtld_hidden_ver(local, name) hidden_ver (local, name)
 593 # define rtld_hidden_data_def(name) hidden_data_def (name)
 594 # define rtld_hidden_data_weak(name) hidden_data_weak (name)
 595 # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name)
 596 #else
 597 # define rtld_hidden_proto(name, attrs...)
 598 # define rtld_hidden_tls_proto(name, attrs...)
 599 # define rtld_hidden_def(name)
 600 # define rtld_hidden_weak(name)
 601 # define rtld_hidden_ver(local, name)
 602 # define rtld_hidden_data_def(name)
 603 # define rtld_hidden_data_weak(name)
 604 # define rtld_hidden_data_ver(local, name)
 605 #endif
 606
 607 #ifdef IS_IN_libm
 608 # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 609 # define libm_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 610 # define libm_hidden_def(name) hidden_def (name)
 611 # define libm_hidden_weak(name) hidden_weak (name)
 612 # define libm_hidden_ver(local, name) hidden_ver (local, name)
 613 # define libm_hidden_data_def(name) hidden_data_def (name)
 614 # define libm_hidden_data_weak(name) hidden_data_weak (name)
 615 # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name)
 616 #else
 617 # define libm_hidden_proto(name, attrs...)
 618 # define libm_hidden_tls_proto(name, attrs...)
 619 # define libm_hidden_def(name)
 620 # define libm_hidden_weak(name)
 621 # define libm_hidden_ver(local, name)
 622 # define libm_hidden_data_def(name)
 623 # define libm_hidden_data_weak(name)
 624 # define libm_hidden_data_ver(local, name)
 625 #endif
 626
 627 #ifdef IS_IN_libresolv
 628 # define libresolv_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 629 # define libresolv_hidden_tls_proto(name, attrs...) \
 630   hidden_tls_proto (name, ##attrs)
 631 # define libresolv_hidden_def(name) hidden_def (name)
 632 # define libresolv_hidden_weak(name) hidden_weak (name)
 633 # define libresolv_hidden_ver(local, name) hidden_ver (local, name)
 634 # define libresolv_hidden_data_def(name) hidden_data_def (name)
 635 # define libresolv_hidden_data_weak(name) hidden_data_weak (name)
 636 # define libresolv_hidden_data_ver(local, name) hidden_data_ver (local, name)
 637 #else
 638 # define libresolv_hidden_proto(name, attrs...)
 639 # define libresolv_hidden_tls_proto(name, attrs...)
 640 # define libresolv_hidden_def(name)
 641 # define libresolv_hidden_weak(name)
 642 # define libresolv_hidden_ver(local, name)
 643 # define libresolv_hidden_data_def(name)
 644 # define libresolv_hidden_data_weak(name)
 645 # define libresolv_hidden_data_ver(local, name)
 646 #endif
 647
 648 #ifdef IS_IN_librt
 649 # define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 650 # define librt_hidden_tls_proto(name, attrs...) \
 651   hidden_tls_proto (name, ##attrs)
 652 # define librt_hidden_def(name) hidden_def (name)
 653 # define librt_hidden_weak(name) hidden_weak (name)
 654 # define librt_hidden_ver(local, name) hidden_ver (local, name)
 655 # define librt_hidden_data_def(name) hidden_data_def (name)
 656 # define librt_hidden_data_weak(name) hidden_data_weak (name)
 657 # define librt_hidden_data_ver(local, name) hidden_data_ver (local, name)
 658 #else
 659 # define librt_hidden_proto(name, attrs...)
 660 # define librt_hidden_tls_proto(name, attrs...)
 661 # define librt_hidden_def(name)
 662 # define librt_hidden_weak(name)
 663 # define librt_hidden_ver(local, name)
 664 # define librt_hidden_data_def(name)
 665 # define librt_hidden_data_weak(name)
 666 # define librt_hidden_data_ver(local, name)
 667 #endif
 668
 669 #ifdef IS_IN_libdl
 670 # define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 671 # define libdl_hidden_tls_proto(name, attrs...) \
 672   hidden_tls_proto (name, ##attrs)
 673 # define libdl_hidden_def(name) hidden_def (name)
 674 # define libdl_hidden_weak(name) hidden_weak (name)
 675 # define libdl_hidden_ver(local, name) hidden_ver (local, name)
 676 # define libdl_hidden_data_def(name) hidden_data_def (name)
 677 # define libdl_hidden_data_weak(name) hidden_data_weak (name)
 678 # define libdl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 679 #else
 680 # define libdl_hidden_proto(name, attrs...)
 681 # define libdl_hidden_tls_proto(name, attrs...)
 682 # define libdl_hidden_def(name)
 683 # define libdl_hidden_weak(name)
 684 # define libdl_hidden_ver(local, name)
 685 # define libdl_hidden_data_def(name)
 686 # define libdl_hidden_data_weak(name)
 687 # define libdl_hidden_data_ver(local, name)
 688 #endif
 689
 690 #ifdef IS_IN_libnss_files
 691 # define libnss_files_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 692 # define libnss_files_hidden_tls_proto(name, attrs...) \
 693   hidden_tls_proto (name, ##attrs)
 694 # define libnss_files_hidden_def(name) hidden_def (name)
 695 # define libnss_files_hidden_weak(name) hidden_weak (name)
 696 # define libnss_files_hidden_ver(local, name) hidden_ver (local, name)
 697 # define libnss_files_hidden_data_def(name) hidden_data_def (name)
 698 # define libnss_files_hidden_data_weak(name) hidden_data_weak (name)
 699 # define libnss_files_hidden_data_ver(local, name) hidden_data_ver(local, name)
 700 #else
 701 # define libnss_files_hidden_proto(name, attrs...)
 702 # define libnss_files_hidden_tls_proto(name, attrs...)
 703 # define libnss_files_hidden_def(name)
 704 # define libnss_files_hidden_weak(name)
 705 # define libnss_files_hidden_ver(local, name)
 706 # define libnss_files_hidden_data_def(name)
 707 # define libnss_files_hidden_data_weak(name)
 708 # define libnss_files_hidden_data_ver(local, name)
 709 #endif
 710
 711 #ifdef IS_IN_libnsl
 712 # define libnsl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 713 # define libnsl_hidden_tls_proto(name, attrs...) \
 714   hidden_tls_proto (name, ##attrs)
 715 # define libnsl_hidden_def(name) hidden_def (name)
 716 # define libnsl_hidden_weak(name) hidden_weak (name)
 717 # define libnsl_hidden_ver(local, name) hidden_ver (local, name)
 718 # define libnsl_hidden_data_def(name) hidden_data_def (name)
 719 # define libnsl_hidden_data_weak(name) hidden_data_weak (name)
 720 # define libnsl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 721 #else
 722 # define libnsl_hidden_proto(name, attrs...)
 723 # define libnsl_hidden_tls_proto(name, attrs...)
 724 # define libnsl_hidden_def(name)
 725 # define libnsl_hidden_weak(name)
 726 # define libnsl_hidden_ver(local, name)
 727 # define libnsl_hidden_data_def(name)
 728 # define libnsl_hidden_data_weak(name)
 729 # define libnsl_hidden_data_ver(local, name)
 730 #endif
 731
 732 #ifdef IS_IN_libnss_nisplus
 733 # define libnss_nisplus_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 734 # define libnss_nisplus_hidden_tls_proto(name, attrs...) \
 735   hidden_tls_proto (name, ##attrs)
 736 # define libnss_nisplus_hidden_def(name) hidden_def (name)
 737 # define libnss_nisplus_hidden_weak(name) hidden_weak (name)
 738 # define libnss_nisplus_hidden_ver(local, name) hidden_ver (local, name)
 739 # define libnss_nisplus_hidden_data_def(name) hidden_data_def (name)
 740 # define libnss_nisplus_hidden_data_weak(name) hidden_data_weak (name)
 741 # define libnss_nisplus_hidden_data_ver(local, name) hidden_data_ver (local, name)
 742 #else
 743 # define libnss_nisplus_hidden_proto(name, attrs...)
 744 # define libnss_nisplus_hidden_tls_proto(name, attrs...)
 745 # define libnss_nisplus_hidden_def(name)
 746 # define libnss_nisplus_hidden_weak(name)
 747 # define libnss_nisplus_hidden_ver(local, name)
 748 # define libnss_nisplus_hidden_data_def(name)
 749 # define libnss_nisplus_hidden_data_weak(name)
 750 # define libnss_nisplus_hidden_data_ver(local, name)
 751 #endif
 752
 753 #define libc_hidden_builtin_proto(name, attrs...) libc_hidden_proto (name, ##attrs)
 754 #define libc_hidden_builtin_def(name) libc_hidden_def (name)
 755 #define libc_hidden_builtin_weak(name) libc_hidden_weak (name)
 756 #define libc_hidden_builtin_ver(local, name) libc_hidden_ver (local, name)
 757 #ifdef __ASSEMBLER__
 758 # define HIDDEN_BUILTIN_JUMPTARGET(name) HIDDEN_JUMPTARGET(name)
 759 #endif
 760
 761 #ifdef IS_IN_libutil
 762 # define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 763 # define libutil_hidden_tls_proto(name, attrs...) \
 764   hidden_tls_proto (name, ##attrs)
 765 # define libutil_hidden_def(name) hidden_def (name)
 766 # define libutil_hidden_weak(name) hidden_weak (name)
 767 # define libutil_hidden_ver(local, name) hidden_ver (local, name)
 768 # define libutil_hidden_data_def(name) hidden_data_def (name)
 769 # define libutil_hidden_data_weak(name) hidden_data_weak (name)
 770 # define libutil_hidden_data_ver(local, name) hidden_data_ver (local, name)
 771 #else
 772 # define libutil_hidden_proto(name, attrs...)
 773 # define libutil_hidden_tls_proto(name, attrs...)
 774 # define libutil_hidden_def(name)
 775 # define libutil_hidden_weak(name)
 776 # define libutil_hidden_ver(local, name)
 777 # define libutil_hidden_data_def(name)
 778 # define libutil_hidden_data_weak(name)
 779 # define libutil_hidden_data_ver(local, name)
 780 #endif
 781
 782 /* Get some dirty hacks.  */
 783 #include <symbol-hacks.h>
 784
 785 /* Move compatibility symbols out of the way by placing them all in a
 786    special section.  */
 787 #ifndef __ASSEMBLER__
 788 # define attribute_compat_text_section \
 789     __attribute__ ((section (".text.compat")))
 790 # define attribute_compat_data_section \
 791     __attribute__ ((section (".data.compat")))
 792 #else
 793 # define compat_text_section .section ".text.compat", "ax";
 794 # define compat_data_section .section ".data.compat", "aw";
 795 #endif
 796
 797 /* Marker used for indirection function symbols.  */
 798 #define libc_ifunc(name, expr)                                          \
 799   extern void *name##_ifunc (void) __asm__ (#name);                     \
 800   void *name##_ifunc (void)                                             \
 801   {                                                                     \
 802     INIT_ARCH ();                                                       \
 803     __typeof (name) *res = expr;                                        \
 804     return res;                                                         \
 805   }                                                                     \
 806   __asm__ (".type " #name ", %gnu_indirect_function");
 807
 808 /* The body of the function is supposed to use __get_cpu_features
 809    which will, if necessary, initialize the data first.  */
 810 #define libm_ifunc(name, expr)                                          \
 811   extern void *name##_ifunc (void) __asm__ (#name);                     \
 812   void *name##_ifunc (void)                                             \
 813   {                                                                     \
 814     __typeof (name) *res = expr;                                        \
 815     return res;                                                         \
 816   }                                                                     \
 817   __asm__ (".type " #name ", %gnu_indirect_function");
 818
 819 #ifdef HAVE_ASM_SET_DIRECTIVE
 820 # define libc_ifunc_hidden_def1(local, name)                            \
 821     __asm__ (".globl " #local "\n\t"                                    \
 822              ".hidden " #local "\n\t"                                   \
 823              ".set " #local ", " #name);
 824 #else
 825 # define libc_ifunc_hidden_def1(local, name)                            \
 826     __asm__ (".globl " #local "\n\t"                                    \
 827              ".hidden " #local "\n\t"                                   \
 828              #local " = " #name);
 829 #endif
 830
 831 #define libc_ifunc_hidden_def(name) \
 832   libc_ifunc_hidden_def1 (__GI_##name, name)
 833
 834 /* Add the compiler optimization to inhibit loop transformation to library
 835    calls.  This is used to avoid recursive calls in memset and memmove
 836    default implementations.  */
 837 #ifdef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
 838 # define inhibit_loop_to_libcall \
 839     __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
 840 #else
 841 # define inhibit_loop_to_libcall
 842 #endif
 843
 844 #endif /* libc-symbols.h */