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) 1995-2015 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 #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 #  define strong_alias(original, alias)                         \
 135   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 136   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 137 #  define strong_data_alias(original, alias) strong_alias(original, alias)
 138 # else
 139 #  define strong_alias(original, alias)                         \
 140   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP             \
 141   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 142 #  define strong_data_alias(original, alias) strong_alias(original, alias)
 143 # endif
 144
 145 # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
 146 #  define weak_alias(original, alias)                                   \
 147   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
 148 #  define weak_extern(symbol)                                           \
 149   .weakext C_SYMBOL_NAME (symbol)
 150
 151 # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 152
 153 #  define weak_alias(original, alias)                                   \
 154   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP                              \
 155   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 156
 157 #  define weak_extern(symbol)                                           \
 158   .weak C_SYMBOL_NAME (symbol)
 159
 160 # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 161
 162 #endif /* __ASSEMBLER__ */
 163
 164 /* On some platforms we can make internal function calls (i.e., calls of
 165    functions not exported) a bit faster by using a different calling
 166    convention.  */
 167 #ifndef internal_function
 168 # define internal_function      /* empty */
 169 #endif
 170
 171 /* Determine the return address.  */
 172 #define RETURN_ADDRESS(nr) \
 173   __builtin_extract_return_addr (__builtin_return_address (nr))
 174
 175 /* When a reference to SYMBOL is encountered, the linker will emit a
 176    warning message MSG.  */
 177 /* We want the .gnu.warning.SYMBOL section to be unallocated.  */
 178 #ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
 179 # define __make_section_unallocated(section_string)     \
 180   asm (".section " section_string "\n\t.previous");
 181 #elif defined HAVE_ASM_POPSECTION_DIRECTIVE
 182 # define __make_section_unallocated(section_string)     \
 183   asm (".pushsection " section_string "\n\t.popsection");
 184 #else
 185 # define __make_section_unallocated(section_string)
 186 #endif
 187
 188 /* Tacking on "\n\t#" to the section name makes gcc put it's bogus
 189    section attributes on what looks like a comment to the assembler.  */
 190 #ifdef HAVE_SECTION_QUOTES
 191 # define __sec_comment "\"\n\t#\""
 192 #else
 193 # define __sec_comment "\n\t#"
 194 #endif
 195 #define link_warning(symbol, msg) \
 196   __make_section_unallocated (".gnu.warning." #symbol) \
 197   static const char __evoke_link_warning_##symbol[]     \
 198     __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
 199     = msg;
 200 #define libc_freeres_ptr(decl) \
 201   __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
 202   decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
 203 #define __libc_freeres_fn_section \
 204   __attribute__ ((section ("__libc_freeres_fn")))
 205
 206 #define libc_freeres_fn(name)   \
 207   static void name (void) __attribute_used__ __libc_freeres_fn_section; \
 208   text_set_element (__libc_subfreeres, name);                           \
 209   static void name (void)
 210
 211 /* A canned warning for sysdeps/stub functions.  */
 212 #define stub_warning(name) \
 213   __make_section_unallocated (".gnu.glibc-stub." #name) \
 214   link_warning (name, #name " is not implemented and will always fail")
 215
 216 /* Warning for linking functions calling dlopen into static binaries.  */
 217 #ifdef SHARED
 218 #define static_link_warning(name)
 219 #else
 220 #define static_link_warning(name) static_link_warning1(name)
 221 #define static_link_warning1(name) \
 222   link_warning(name, "Using '" #name "' in statically linked applications \
 223 requires at runtime the shared libraries from the glibc version used \
 224 for linking")
 225 #endif
 226
 227 /* Declare SYMBOL to be TYPE (`function' or `object') of SIZE bytes
 228    alias to ORIGINAL, when the assembler supports such declarations
 229    (such as in ELF).
 230    This is only necessary when defining something in assembly, or playing
 231    funny alias games where the size should be other than what the compiler
 232    thinks it is.  */
 233 #define declare_symbol_alias(symbol, original, type, size) \
 234   declare_symbol_alias_1 (symbol, original, type, size)
 235 #ifdef __ASSEMBLER__
 236 # define declare_symbol_alias_1(symbol, original, type, size) \
 237    strong_alias (original, symbol); \
 238    .type C_SYMBOL_NAME (symbol), %##type; \
 239    .size C_SYMBOL_NAME (symbol), size
 240 #else /* Not __ASSEMBLER__.  */
 241 # define declare_symbol_alias_1(symbol, original, type, size) \
 242    asm (".globl " __SYMBOL_PREFIX #symbol \
 243         "\n\t" declare_symbol_alias_1_alias (symbol, original) \
 244         "\n\t.type " __SYMBOL_PREFIX #symbol ", " \
 245         "%" #type \
 246         "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size);
 247 # ifdef HAVE_ASM_SET_DIRECTIVE
 248 #  define declare_symbol_alias_1_alias(symbol, original) \
 249      ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX #original
 250 # else
 251 #  define declare_symbol_alias_1_alias(symbol, original) \
 252      __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX #original
 253 # endif /* HAVE_ASM_SET_DIRECTIVE */
 254 #endif /* __ASSEMBLER__ */
 255
 256
 257 /*
 258 \f
 259 */
 260
 261 /* Symbol set support macros.  */
 262
 263 /* Make SYMBOL, which is in the text segment, an element of SET.  */
 264 #define text_set_element(set, symbol)   _elf_set_element(set, symbol)
 265 /* Make SYMBOL, which is in the data segment, an element of SET.  */
 266 #define data_set_element(set, symbol)   _elf_set_element(set, symbol)
 267 /* Make SYMBOL, which is in the bss segment, an element of SET.  */
 268 #define bss_set_element(set, symbol)    _elf_set_element(set, symbol)
 269
 270 /* These are all done the same way in ELF.
 271    There is a new section created for each set.  */
 272 #ifdef SHARED
 273 /* When building a shared library, make the set section writable,
 274    because it will need to be relocated at run time anyway.  */
 275 # define _elf_set_element(set, symbol) \
 276   static const void *__elf_set_##set##_element_##symbol##__ \
 277     __attribute__ ((used, section (#set))) = &(symbol)
 278 #else
 279 # define _elf_set_element(set, symbol) \
 280   static const void *const __elf_set_##set##_element_##symbol##__ \
 281     __attribute__ ((used, section (#set))) = &(symbol)
 282 #endif
 283
 284 /* Define SET as a symbol set.  This may be required (it is in a.out) to
 285    be able to use the set's contents.  */
 286 #define symbol_set_define(set)  symbol_set_declare(set)
 287
 288 /* Declare SET for use in this module, if defined in another module.
 289    In a shared library, this is always local to that shared object.
 290    For static linking, the set might be wholly absent and so we use
 291    weak references.  */
 292 #define symbol_set_declare(set) \
 293   extern char const __start_##set[] __symbol_set_attribute; \
 294   extern char const __stop_##set[] __symbol_set_attribute;
 295 #ifdef SHARED
 296 # define __symbol_set_attribute attribute_hidden
 297 #else
 298 # define __symbol_set_attribute __attribute__ ((weak))
 299 #endif
 300
 301 /* Return a pointer (void *const *) to the first element of SET.  */
 302 #define symbol_set_first_element(set)   ((void *const *) (&__start_##set))
 303
 304 /* Return true iff PTR (a void *const *) has been incremented
 305    past the last element in SET.  */
 306 #define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
 307
 308 #ifdef SHARED
 309 # define symbol_version(real, name, version) \
 310      _symbol_version(real, name, version)
 311 # define default_symbol_version(real, name, version) \
 312      _default_symbol_version(real, name, version)
 313 # ifdef __ASSEMBLER__
 314 #  define _symbol_version(real, name, version) \
 315      .symver real, name##@##version
 316 #  define _default_symbol_version(real, name, version) \
 317      .symver real, name##@##@##version
 318 # else
 319 #  define _symbol_version(real, name, version) \
 320      __asm__ (".symver " #real "," #name "@" #version)
 321 #  define _default_symbol_version(real, name, version) \
 322      __asm__ (".symver " #real "," #name "@@" #version)
 323 # endif
 324 #else
 325 # define symbol_version(real, name, version)
 326 # define default_symbol_version(real, name, version) \
 327   strong_alias(real, name)
 328 #endif
 329
 330 #if defined SHARED || defined LIBC_NONSHARED
 331 # define attribute_hidden __attribute__ ((visibility ("hidden")))
 332 #else
 333 # define attribute_hidden
 334 #endif
 335
 336 #define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
 337
 338 #define attribute_relro __attribute__ ((section (".data.rel.ro")))
 339
 340 /* The following macros are used for PLT bypassing within libc.so
 341    (and if needed other libraries similarly).
 342    First of all, you need to have the function prototyped somewhere,
 343    say in foo/foo.h:
 344
 345    int foo (int __bar);
 346
 347    If calls to foo within libc.so should always go to foo defined in libc.so,
 348    then in include/foo.h you add:
 349
 350    libc_hidden_proto (foo)
 351
 352    line and after the foo function definition:
 353
 354    int foo (int __bar)
 355    {
 356      return __bar;
 357    }
 358    libc_hidden_def (foo)
 359
 360    or
 361
 362    int foo (int __bar)
 363    {
 364      return __bar;
 365    }
 366    libc_hidden_weak (foo)
 367
 368    Similarly for global data.  If references to foo within libc.so should
 369    always go to foo defined in libc.so, then in include/foo.h you add:
 370
 371    libc_hidden_proto (foo)
 372
 373    line and after foo's definition:
 374
 375    int foo = INITIAL_FOO_VALUE;
 376    libc_hidden_data_def (foo)
 377
 378    or
 379
 380    int foo = INITIAL_FOO_VALUE;
 381    libc_hidden_data_weak (foo)
 382
 383    If foo is normally just an alias (strong or weak) to some other function,
 384    you should use the normal strong_alias first, then add libc_hidden_def
 385    or libc_hidden_weak:
 386
 387    int baz (int __bar)
 388    {
 389      return __bar;
 390    }
 391    strong_alias (baz, foo)
 392    libc_hidden_weak (foo)
 393
 394    If the function should be internal to multiple objects, say ld.so and
 395    libc.so, the best way is to use:
 396
 397    #if IS_IN (libc) || IS_IN (rtld)
 398    hidden_proto (foo)
 399    #endif
 400
 401    in include/foo.h and the normal macros at all function definitions
 402    depending on what DSO they belong to.
 403
 404    If versioned_symbol macro is used to define foo,
 405    libc_hidden_ver macro should be used, as in:
 406
 407    int __real_foo (int __bar)
 408    {
 409      return __bar;
 410    }
 411    versioned_symbol (libc, __real_foo, foo, GLIBC_2_1);
 412    libc_hidden_ver (__real_foo, foo)  */
 413
 414 #if defined SHARED && !defined NO_HIDDEN
 415 # ifndef __ASSEMBLER__
 416 #  define __hidden_proto_hiddenattr(attrs...) \
 417   __attribute__ ((visibility ("hidden"), ##attrs))
 418 #  define hidden_proto(name, attrs...) \
 419   __hidden_proto (name, , __GI_##name, ##attrs)
 420 #  define hidden_tls_proto(name, attrs...) \
 421   __hidden_proto (name, __thread, __GI_##name, ##attrs)
 422 #  define __hidden_proto(name, thread, internal, attrs...)           \
 423   extern thread __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
 424   __hidden_proto_hiddenattr (attrs);
 425 #  define __hidden_asmname(name) \
 426   __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
 427 #  define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
 428 #  define __hidden_asmname2(prefix, name) #prefix name
 429 #  define __hidden_ver1(local, internal, name) \
 430   extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
 431   extern __typeof (name) __EI_##name \
 432         __attribute__((alias (__hidden_asmname (#local))))
 433 #  define hidden_ver(local, name)       __hidden_ver1(local, __GI_##name, name);
 434 #  define hidden_data_ver(local, name)  hidden_ver(local, name)
 435 #  define hidden_def(name)              __hidden_ver1(__GI_##name, name, name);
 436 #  define hidden_data_def(name)         hidden_def(name)
 437 #  define hidden_weak(name) \
 438         __hidden_ver1(__GI_##name, name, name) __attribute__((weak));
 439 #  define hidden_data_weak(name)        hidden_weak(name)
 440 #  define hidden_nolink(name, lib, version) \
 441   __hidden_nolink1 (__GI_##name, __EI_##name, name, VERSION_##lib##_##version)
 442 #  define __hidden_nolink1(local, internal, name, version) \
 443   __hidden_nolink2 (local, internal, name, version)
 444 #  define __hidden_nolink2(local, internal, name, version) \
 445   extern __typeof (name) internal __attribute__ ((alias (#local))); \
 446   __hidden_nolink3 (local, internal, #name "@" #version)
 447 #  define __hidden_nolink3(local, internal, vername) \
 448   __asm__ (".symver " #internal ", " vername);
 449 # else
 450 /* For assembly, we need to do the opposite of what we do in C:
 451    in assembly gcc __REDIRECT stuff is not in place, so functions
 452    are defined by its normal name and we need to create the
 453    __GI_* alias to it, in C __REDIRECT causes the function definition
 454    to use __GI_* name and we need to add alias to the real name.
 455    There is no reason to use hidden_weak over hidden_def in assembly,
 456    but we provide it for consistency with the C usage.
 457    hidden_proto doesn't make sense for assembly but the equivalent
 458    is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET.  */
 459 #  define hidden_def(name)      strong_alias (name, __GI_##name)
 460 #  define hidden_weak(name)     hidden_def (name)
 461 #  define hidden_ver(local, name) strong_alias (local, __GI_##name)
 462 #  define hidden_data_def(name) strong_data_alias (name, __GI_##name)
 463 #  define hidden_data_weak(name)        hidden_data_def (name)
 464 #  define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
 465 #  define HIDDEN_JUMPTARGET(name) __GI_##name
 466 # endif
 467 #else
 468 # ifndef __ASSEMBLER__
 469 #  define hidden_proto(name, attrs...)
 470 #  define hidden_tls_proto(name, attrs...)
 471 # else
 472 #  define HIDDEN_JUMPTARGET(name) JUMPTARGET(name)
 473 # endif /* Not  __ASSEMBLER__ */
 474 # define hidden_weak(name)
 475 # define hidden_def(name)
 476 # define hidden_ver(local, name)
 477 # define hidden_data_weak(name)
 478 # define hidden_data_def(name)
 479 # define hidden_data_ver(local, name)
 480 # define hidden_nolink(name, lib, version)
 481 #endif
 482
 483 #if IS_IN (libc)
 484 # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 485 # define libc_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 486 # define libc_hidden_def(name) hidden_def (name)
 487 # define libc_hidden_weak(name) hidden_weak (name)
 488 # ifdef LINK_OBSOLETE_RPC
 489    /* libc_hidden_nolink_sunrpc should only get used in sunrpc code.  */
 490 #  define libc_hidden_nolink_sunrpc(name, version) hidden_def (name)
 491 # else
 492 #  define libc_hidden_nolink_sunrpc(name, version) hidden_nolink (name, libc, version)
 493 # endif
 494 # define libc_hidden_ver(local, name) hidden_ver (local, name)
 495 # define libc_hidden_data_def(name) hidden_data_def (name)
 496 # define libc_hidden_data_weak(name) hidden_data_weak (name)
 497 # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
 498 #else
 499 # define libc_hidden_proto(name, attrs...)
 500 # define libc_hidden_tls_proto(name, attrs...)
 501 # define libc_hidden_def(name)
 502 # define libc_hidden_weak(name)
 503 # define libc_hidden_ver(local, name)
 504 # define libc_hidden_data_def(name)
 505 # define libc_hidden_data_weak(name)
 506 # define libc_hidden_data_ver(local, name)
 507 #endif
 508
 509 #if IS_IN (rtld)
 510 # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 511 # define rtld_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 512 # define rtld_hidden_def(name) hidden_def (name)
 513 # define rtld_hidden_weak(name) hidden_weak (name)
 514 # define rtld_hidden_ver(local, name) hidden_ver (local, name)
 515 # define rtld_hidden_data_def(name) hidden_data_def (name)
 516 # define rtld_hidden_data_weak(name) hidden_data_weak (name)
 517 # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name)
 518 #else
 519 # define rtld_hidden_proto(name, attrs...)
 520 # define rtld_hidden_tls_proto(name, attrs...)
 521 # define rtld_hidden_def(name)
 522 # define rtld_hidden_weak(name)
 523 # define rtld_hidden_ver(local, name)
 524 # define rtld_hidden_data_def(name)
 525 # define rtld_hidden_data_weak(name)
 526 # define rtld_hidden_data_ver(local, name)
 527 #endif
 528
 529 #if IS_IN (libm)
 530 # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 531 # define libm_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
 532 # define libm_hidden_def(name) hidden_def (name)
 533 # define libm_hidden_weak(name) hidden_weak (name)
 534 # define libm_hidden_ver(local, name) hidden_ver (local, name)
 535 # define libm_hidden_data_def(name) hidden_data_def (name)
 536 # define libm_hidden_data_weak(name) hidden_data_weak (name)
 537 # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name)
 538 #else
 539 # define libm_hidden_proto(name, attrs...)
 540 # define libm_hidden_tls_proto(name, attrs...)
 541 # define libm_hidden_def(name)
 542 # define libm_hidden_weak(name)
 543 # define libm_hidden_ver(local, name)
 544 # define libm_hidden_data_def(name)
 545 # define libm_hidden_data_weak(name)
 546 # define libm_hidden_data_ver(local, name)
 547 #endif
 548
 549 #if IS_IN (libresolv)
 550 # define libresolv_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 551 # define libresolv_hidden_tls_proto(name, attrs...) \
 552   hidden_tls_proto (name, ##attrs)
 553 # define libresolv_hidden_def(name) hidden_def (name)
 554 # define libresolv_hidden_weak(name) hidden_weak (name)
 555 # define libresolv_hidden_ver(local, name) hidden_ver (local, name)
 556 # define libresolv_hidden_data_def(name) hidden_data_def (name)
 557 # define libresolv_hidden_data_weak(name) hidden_data_weak (name)
 558 # define libresolv_hidden_data_ver(local, name) hidden_data_ver (local, name)
 559 #else
 560 # define libresolv_hidden_proto(name, attrs...)
 561 # define libresolv_hidden_tls_proto(name, attrs...)
 562 # define libresolv_hidden_def(name)
 563 # define libresolv_hidden_weak(name)
 564 # define libresolv_hidden_ver(local, name)
 565 # define libresolv_hidden_data_def(name)
 566 # define libresolv_hidden_data_weak(name)
 567 # define libresolv_hidden_data_ver(local, name)
 568 #endif
 569
 570 #if IS_IN (librt)
 571 # define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 572 # define librt_hidden_tls_proto(name, attrs...) \
 573   hidden_tls_proto (name, ##attrs)
 574 # define librt_hidden_def(name) hidden_def (name)
 575 # define librt_hidden_weak(name) hidden_weak (name)
 576 # define librt_hidden_ver(local, name) hidden_ver (local, name)
 577 # define librt_hidden_data_def(name) hidden_data_def (name)
 578 # define librt_hidden_data_weak(name) hidden_data_weak (name)
 579 # define librt_hidden_data_ver(local, name) hidden_data_ver (local, name)
 580 #else
 581 # define librt_hidden_proto(name, attrs...)
 582 # define librt_hidden_tls_proto(name, attrs...)
 583 # define librt_hidden_def(name)
 584 # define librt_hidden_weak(name)
 585 # define librt_hidden_ver(local, name)
 586 # define librt_hidden_data_def(name)
 587 # define librt_hidden_data_weak(name)
 588 # define librt_hidden_data_ver(local, name)
 589 #endif
 590
 591 #if IS_IN (libdl)
 592 # define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 593 # define libdl_hidden_tls_proto(name, attrs...) \
 594   hidden_tls_proto (name, ##attrs)
 595 # define libdl_hidden_def(name) hidden_def (name)
 596 # define libdl_hidden_weak(name) hidden_weak (name)
 597 # define libdl_hidden_ver(local, name) hidden_ver (local, name)
 598 # define libdl_hidden_data_def(name) hidden_data_def (name)
 599 # define libdl_hidden_data_weak(name) hidden_data_weak (name)
 600 # define libdl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 601 #else
 602 # define libdl_hidden_proto(name, attrs...)
 603 # define libdl_hidden_tls_proto(name, attrs...)
 604 # define libdl_hidden_def(name)
 605 # define libdl_hidden_weak(name)
 606 # define libdl_hidden_ver(local, name)
 607 # define libdl_hidden_data_def(name)
 608 # define libdl_hidden_data_weak(name)
 609 # define libdl_hidden_data_ver(local, name)
 610 #endif
 611
 612 #if IS_IN (libnss_files)
 613 # define libnss_files_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 614 # define libnss_files_hidden_tls_proto(name, attrs...) \
 615   hidden_tls_proto (name, ##attrs)
 616 # define libnss_files_hidden_def(name) hidden_def (name)
 617 # define libnss_files_hidden_weak(name) hidden_weak (name)
 618 # define libnss_files_hidden_ver(local, name) hidden_ver (local, name)
 619 # define libnss_files_hidden_data_def(name) hidden_data_def (name)
 620 # define libnss_files_hidden_data_weak(name) hidden_data_weak (name)
 621 # define libnss_files_hidden_data_ver(local, name) hidden_data_ver(local, name)
 622 #else
 623 # define libnss_files_hidden_proto(name, attrs...)
 624 # define libnss_files_hidden_tls_proto(name, attrs...)
 625 # define libnss_files_hidden_def(name)
 626 # define libnss_files_hidden_weak(name)
 627 # define libnss_files_hidden_ver(local, name)
 628 # define libnss_files_hidden_data_def(name)
 629 # define libnss_files_hidden_data_weak(name)
 630 # define libnss_files_hidden_data_ver(local, name)
 631 #endif
 632
 633 #if IS_IN (libnsl)
 634 # define libnsl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 635 # define libnsl_hidden_tls_proto(name, attrs...) \
 636   hidden_tls_proto (name, ##attrs)
 637 # define libnsl_hidden_def(name) hidden_def (name)
 638 # define libnsl_hidden_weak(name) hidden_weak (name)
 639 # define libnsl_hidden_ver(local, name) hidden_ver (local, name)
 640 # define libnsl_hidden_data_def(name) hidden_data_def (name)
 641 # define libnsl_hidden_data_weak(name) hidden_data_weak (name)
 642 # define libnsl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 643 #else
 644 # define libnsl_hidden_proto(name, attrs...)
 645 # define libnsl_hidden_tls_proto(name, attrs...)
 646 # define libnsl_hidden_def(name)
 647 # define libnsl_hidden_weak(name)
 648 # define libnsl_hidden_ver(local, name)
 649 # define libnsl_hidden_data_def(name)
 650 # define libnsl_hidden_data_weak(name)
 651 # define libnsl_hidden_data_ver(local, name)
 652 #endif
 653
 654 #if IS_IN (libnss_nisplus)
 655 # define libnss_nisplus_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 656 # define libnss_nisplus_hidden_tls_proto(name, attrs...) \
 657   hidden_tls_proto (name, ##attrs)
 658 # define libnss_nisplus_hidden_def(name) hidden_def (name)
 659 # define libnss_nisplus_hidden_weak(name) hidden_weak (name)
 660 # define libnss_nisplus_hidden_ver(local, name) hidden_ver (local, name)
 661 # define libnss_nisplus_hidden_data_def(name) hidden_data_def (name)
 662 # define libnss_nisplus_hidden_data_weak(name) hidden_data_weak (name)
 663 # define libnss_nisplus_hidden_data_ver(local, name) hidden_data_ver (local, name)
 664 #else
 665 # define libnss_nisplus_hidden_proto(name, attrs...)
 666 # define libnss_nisplus_hidden_tls_proto(name, attrs...)
 667 # define libnss_nisplus_hidden_def(name)
 668 # define libnss_nisplus_hidden_weak(name)
 669 # define libnss_nisplus_hidden_ver(local, name)
 670 # define libnss_nisplus_hidden_data_def(name)
 671 # define libnss_nisplus_hidden_data_weak(name)
 672 # define libnss_nisplus_hidden_data_ver(local, name)
 673 #endif
 674
 675 #define libc_hidden_builtin_proto(name, attrs...) libc_hidden_proto (name, ##attrs)
 676 #define libc_hidden_builtin_def(name) libc_hidden_def (name)
 677 #define libc_hidden_builtin_weak(name) libc_hidden_weak (name)
 678 #define libc_hidden_builtin_ver(local, name) libc_hidden_ver (local, name)
 679 #ifdef __ASSEMBLER__
 680 # define HIDDEN_BUILTIN_JUMPTARGET(name) HIDDEN_JUMPTARGET(name)
 681 #endif
 682
 683 #if IS_IN (libutil)
 684 # define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 685 # define libutil_hidden_tls_proto(name, attrs...) \
 686   hidden_tls_proto (name, ##attrs)
 687 # define libutil_hidden_def(name) hidden_def (name)
 688 # define libutil_hidden_weak(name) hidden_weak (name)
 689 # define libutil_hidden_ver(local, name) hidden_ver (local, name)
 690 # define libutil_hidden_data_def(name) hidden_data_def (name)
 691 # define libutil_hidden_data_weak(name) hidden_data_weak (name)
 692 # define libutil_hidden_data_ver(local, name) hidden_data_ver (local, name)
 693 #else
 694 # define libutil_hidden_proto(name, attrs...)
 695 # define libutil_hidden_tls_proto(name, attrs...)
 696 # define libutil_hidden_def(name)
 697 # define libutil_hidden_weak(name)
 698 # define libutil_hidden_ver(local, name)
 699 # define libutil_hidden_data_def(name)
 700 # define libutil_hidden_data_weak(name)
 701 # define libutil_hidden_data_ver(local, name)
 702 #endif
 703
 704 /* Get some dirty hacks.  */
 705 #include <symbol-hacks.h>
 706
 707 /* Move compatibility symbols out of the way by placing them all in a
 708    special section.  */
 709 #ifndef __ASSEMBLER__
 710 # define attribute_compat_text_section \
 711     __attribute__ ((section (".text.compat")))
 712 # define attribute_compat_data_section \
 713     __attribute__ ((section (".data.compat")))
 714 #else
 715 # define compat_text_section .section ".text.compat", "ax";
 716 # define compat_data_section .section ".data.compat", "aw";
 717 #endif
 718
 719 /* Marker used for indirection function symbols.  */
 720 #define libc_ifunc(name, expr)                                          \
 721   extern void *name##_ifunc (void) __asm__ (#name);                     \
 722   void *name##_ifunc (void)                                             \
 723   {                                                                     \
 724     INIT_ARCH ();                                                       \
 725     __typeof (name) *res = expr;                                        \
 726     return res;                                                         \
 727   }                                                                     \
 728   __asm__ (".type " #name ", %gnu_indirect_function");
 729
 730 /* The body of the function is supposed to use __get_cpu_features
 731    which will, if necessary, initialize the data first.  */
 732 #define libm_ifunc(name, expr)                                          \
 733   extern void *name##_ifunc (void) __asm__ (#name);                     \
 734   void *name##_ifunc (void)                                             \
 735   {                                                                     \
 736     __typeof (name) *res = expr;                                        \
 737     return res;                                                         \
 738   }                                                                     \
 739   __asm__ (".type " #name ", %gnu_indirect_function");
 740
 741 #ifdef HAVE_ASM_SET_DIRECTIVE
 742 # define libc_ifunc_hidden_def1(local, name)                            \
 743     __asm__ (".globl " #local "\n\t"                                    \
 744              ".hidden " #local "\n\t"                                   \
 745              ".set " #local ", " #name);
 746 #else
 747 # define libc_ifunc_hidden_def1(local, name)                            \
 748     __asm__ (".globl " #local "\n\t"                                    \
 749              ".hidden " #local "\n\t"                                   \
 750              #local " = " #name);
 751 #endif
 752
 753 #define libc_ifunc_hidden_def(name) \
 754   libc_ifunc_hidden_def1 (__GI_##name, name)
 755
 756 /* Add the compiler optimization to inhibit loop transformation to library
 757    calls.  This is used to avoid recursive calls in memset and memmove
 758    default implementations.  */
 759 #ifdef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
 760 # define inhibit_loop_to_libcall \
 761     __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
 762 #else
 763 # define inhibit_loop_to_libcall
 764 #endif
 765
 766 #endif /* libc-symbols.h */