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			787 lines
		
	
	
		
			30 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			787 lines
		
	
	
		
			30 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Support macros for making weak and strong aliases for symbols,
 | ||
|    and for using symbol sets and linker warnings with GNU ld.
 | ||
|    Copyright (C) 1995-2012 Free Software Foundation, Inc.
 | ||
|    This file is part of the GNU C Library.
 | ||
| 
 | ||
|    The GNU C Library is free software; you can redistribute it and/or
 | ||
|    modify it under the terms of the GNU Lesser General Public
 | ||
|    License as published by the Free Software Foundation; either
 | ||
|    version 2.1 of the License, or (at your option) any later version.
 | ||
| 
 | ||
|    The GNU C Library is distributed in the hope that it will be useful,
 | ||
|    but WITHOUT ANY WARRANTY; without even the implied warranty of
 | ||
|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 | ||
|    Lesser General Public License for more details.
 | ||
| 
 | ||
|    You should have received a copy of the GNU Lesser General Public
 | ||
|    License along with the GNU C Library; if not, see
 | ||
|    <http://www.gnu.org/licenses/>.  */
 | ||
| 
 | ||
| #ifndef _LIBC_SYMBOLS_H
 | ||
| #define _LIBC_SYMBOLS_H	1
 | ||
| 
 | ||
| /* This file's macros are included implicitly in the compilation of every
 | ||
|    file in the C library by -imacros.
 | ||
| 
 | ||
|    We include config.h which is generated by configure.
 | ||
|    It should define for us the following symbols:
 | ||
| 
 | ||
|    * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'.
 | ||
|    * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'.
 | ||
|    * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'.
 | ||
| 
 | ||
|    */
 | ||
| 
 | ||
| /* This is defined for the compilation of all C library code.  features.h
 | ||
|    tests this to avoid inclusion of stubs.h while compiling the library,
 | ||
|    before stubs.h has been generated.  Some library code that is shared
 | ||
|    with other packages also tests this symbol to see if it is being
 | ||
|    compiled as part of the C library.  We must define this before including
 | ||
|    config.h, because it makes some definitions conditional on whether libc
 | ||
|    itself is being compiled, or just some generator program.  */
 | ||
| #define _LIBC	1
 | ||
| 
 | ||
| /* Enable declarations of GNU extensions, since we are compiling them.  */
 | ||
| #define _GNU_SOURCE	1
 | ||
| /* And we also need the data for the reentrant functions.  */
 | ||
| #define _REENTRANT	1
 | ||
| 
 | ||
| #include <config.h>
 | ||
| 
 | ||
| /* The symbols in all the user (non-_) macros are C symbols.  */
 | ||
| 
 | ||
| #if !defined HAVE_ASM_WEAK_DIRECTIVE && !defined HAVE_ASM_WEAKEXT_DIRECTIVE
 | ||
| # error "weak symbol support needed"
 | ||
| #endif
 | ||
| 
 | ||
| #ifndef __SYMBOL_PREFIX
 | ||
| # define __SYMBOL_PREFIX
 | ||
| #endif
 | ||
| 
 | ||
| #ifndef C_SYMBOL_NAME
 | ||
| # define C_SYMBOL_NAME(name) name
 | ||
| #endif
 | ||
| 
 | ||
| #ifndef ASM_LINE_SEP
 | ||
| # define ASM_LINE_SEP ;
 | ||
| #endif
 | ||
| 
 | ||
| #ifdef HAVE_ASM_GLOBAL_DOT_NAME
 | ||
| # ifndef C_SYMBOL_DOT_NAME
 | ||
| #  if defined __GNUC__ && defined __GNUC_MINOR__ \
 | ||
|       && (__GNUC__ << 16) + __GNUC_MINOR__ >= (3 << 16) + 1
 | ||
| #   define C_SYMBOL_DOT_NAME(name) .name
 | ||
| #  else
 | ||
| #   define C_SYMBOL_DOT_NAME(name) .##name
 | ||
| #  endif
 | ||
| # endif
 | ||
| #endif
 | ||
| 
 | ||
| #ifndef __ASSEMBLER__
 | ||
| /* GCC understands weak symbols and aliases; use its interface where
 | ||
|    possible, instead of embedded assembly language.  */
 | ||
| 
 | ||
| /* Define ALIASNAME as a strong alias for NAME.  */
 | ||
| # define strong_alias(name, aliasname) _strong_alias(name, aliasname)
 | ||
| # define _strong_alias(name, aliasname) \
 | ||
|   extern __typeof (name) aliasname __attribute__ ((alias (#name)));
 | ||
| 
 | ||
| /* This comes between the return type and function name in
 | ||
|    a function definition to make that definition weak.  */
 | ||
| # define weak_function __attribute__ ((weak))
 | ||
| # define weak_const_function __attribute__ ((weak, __const__))
 | ||
| 
 | ||
| /* Define ALIASNAME as a weak alias for NAME.
 | ||
|    If weak aliases are not available, this defines a strong alias.  */
 | ||
| # define weak_alias(name, aliasname) _weak_alias (name, aliasname)
 | ||
| # define _weak_alias(name, aliasname) \
 | ||
|   extern __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
 | ||
| 
 | ||
| /* Same as WEAK_ALIAS, but mark symbol as hidden.  */
 | ||
| # define weak_hidden_alias(name, aliasname) \
 | ||
|   _weak_hidden_alias (name, aliasname)
 | ||
| # define _weak_hidden_alias(name, aliasname) \
 | ||
|   extern __typeof (name) aliasname \
 | ||
|     __attribute__ ((weak, alias (#name), __visibility__ ("hidden")));
 | ||
| 
 | ||
| /* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined).  */
 | ||
| # define weak_extern(symbol) _weak_extern (weak symbol)
 | ||
| # define _weak_extern(expr) _Pragma (#expr)
 | ||
| 
 | ||
| 
 | ||
| #else /* __ASSEMBLER__ */
 | ||
| 
 | ||
| # ifdef HAVE_ASM_SET_DIRECTIVE
 | ||
| #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 | ||
| #   define strong_alias(original, alias)				\
 | ||
|   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP		\
 | ||
|   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP	\
 | ||
|   .globl C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP		\
 | ||
|   .set C_SYMBOL_DOT_NAME (alias),C_SYMBOL_DOT_NAME (original)
 | ||
| #   define strong_data_alias(original, alias)				\
 | ||
|   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP		\
 | ||
|   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 | ||
| #  else
 | ||
| #   define strong_alias(original, alias)				\
 | ||
|   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP		\
 | ||
|   .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
 | ||
| #   define strong_data_alias(original, alias) strong_alias(original, alias)
 | ||
| #  endif
 | ||
| # else
 | ||
| #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 | ||
| #   define strong_alias(original, alias)				\
 | ||
|   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP		\
 | ||
|   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP		\
 | ||
|   .globl C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP		\
 | ||
|   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 | ||
| #   define strong_data_alias(original, alias)				\
 | ||
|   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP		\
 | ||
|   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 | ||
| #  else
 | ||
| #   define strong_alias(original, alias)				\
 | ||
|   .globl C_SYMBOL_NAME (alias) ASM_LINE_SEP		\
 | ||
|   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 | ||
| #   define strong_data_alias(original, alias) strong_alias(original, alias)
 | ||
| #  endif
 | ||
| # endif
 | ||
| 
 | ||
| # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
 | ||
| #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 | ||
| #   define weak_alias(original, alias)					\
 | ||
|   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) ASM_LINE_SEP \
 | ||
|   .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
 | ||
| #  else
 | ||
| #   define weak_alias(original, alias)					\
 | ||
|   .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
 | ||
| #  endif
 | ||
| #  define weak_extern(symbol)						\
 | ||
|   .weakext C_SYMBOL_NAME (symbol)
 | ||
| 
 | ||
| # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 | ||
| 
 | ||
| #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 | ||
| #   define weak_alias(original, alias)					\
 | ||
|   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP				\
 | ||
|   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP		\
 | ||
|   .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP				\
 | ||
|   C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
 | ||
| #  else
 | ||
| #   define weak_alias(original, alias)					\
 | ||
|   .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP				\
 | ||
|   C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
 | ||
| #  endif
 | ||
| 
 | ||
| #  define weak_extern(symbol)						\
 | ||
|   .weak C_SYMBOL_NAME (symbol)
 | ||
| 
 | ||
| # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
 | ||
| 
 | ||
| #endif /* __ASSEMBLER__ */
 | ||
| 
 | ||
| /* On some platforms we can make internal function calls (i.e., calls of
 | ||
|    functions not exported) a bit faster by using a different calling
 | ||
|    convention.  */
 | ||
| #ifndef internal_function
 | ||
| # define internal_function	/* empty */
 | ||
| #endif
 | ||
| 
 | ||
| /* Determine the return address.  */
 | ||
| #define RETURN_ADDRESS(nr) \
 | ||
|   __builtin_extract_return_addr (__builtin_return_address (nr))
 | ||
| 
 | ||
| /* When a reference to SYMBOL is encountered, the linker will emit a
 | ||
|    warning message MSG.  */
 | ||
| /* We want the .gnu.warning.SYMBOL section to be unallocated.  */
 | ||
| #ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
 | ||
| # define __make_section_unallocated(section_string)	\
 | ||
|   asm (".section " section_string "\n\t.previous");
 | ||
| #elif defined HAVE_ASM_POPSECTION_DIRECTIVE
 | ||
| # define __make_section_unallocated(section_string)	\
 | ||
|   asm (".pushsection " section_string "\n\t.popsection");
 | ||
| #else
 | ||
| # define __make_section_unallocated(section_string)
 | ||
| #endif
 | ||
| 
 | ||
| /* Tacking on "\n\t#" to the section name makes gcc put it's bogus
 | ||
|    section attributes on what looks like a comment to the assembler.  */
 | ||
| #ifdef HAVE_SECTION_QUOTES
 | ||
| # define __sec_comment "\"\n\t#\""
 | ||
| #else
 | ||
| # define __sec_comment "\n\t#"
 | ||
| #endif
 | ||
| #define link_warning(symbol, msg) \
 | ||
|   __make_section_unallocated (".gnu.warning." #symbol) \
 | ||
|   static const char __evoke_link_warning_##symbol[]	\
 | ||
|     __attribute__ ((used, section (".gnu.warning." #symbol __sec_comment))) \
 | ||
|     = msg;
 | ||
| #define libc_freeres_ptr(decl) \
 | ||
|   __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
 | ||
|   decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
 | ||
| #define __libc_freeres_fn_section \
 | ||
|   __attribute__ ((section ("__libc_freeres_fn")))
 | ||
| 
 | ||
| #define libc_freeres_fn(name)	\
 | ||
|   static void name (void) __attribute_used__ __libc_freeres_fn_section;	\
 | ||
|   text_set_element (__libc_subfreeres, name);				\
 | ||
|   static void name (void)
 | ||
| 
 | ||
| /* A canned warning for sysdeps/stub functions.  */
 | ||
| #define	stub_warning(name) \
 | ||
|   __make_section_unallocated (".gnu.glibc-stub." #name) \
 | ||
|   link_warning (name, \
 | ||
| 		"warning: " #name " is not implemented and will always fail")
 | ||
| 
 | ||
| /* Warning for linking functions calling dlopen into static binaries.  */
 | ||
| #ifdef SHARED
 | ||
| #define static_link_warning(name)
 | ||
| #else
 | ||
| #define static_link_warning(name) static_link_warning1(name)
 | ||
| #define static_link_warning1(name) \
 | ||
|   link_warning(name, "Using '" #name "' in statically linked applications \
 | ||
| requires at runtime the shared libraries from the glibc version used \
 | ||
| for linking")
 | ||
| #endif
 | ||
| 
 | ||
| /* Declare SYMBOL to be TYPE (`function' or `object') of SIZE bytes
 | ||
|    alias to ORIGINAL, when the assembler supports such declarations
 | ||
|    (such as in ELF).
 | ||
|    This is only necessary when defining something in assembly, or playing
 | ||
|    funny alias games where the size should be other than what the compiler
 | ||
|    thinks it is.  */
 | ||
| #define declare_symbol_alias(symbol, original, type, size) \
 | ||
|   declare_symbol_alias_1 (symbol, original, type, size)
 | ||
| #ifdef __ASSEMBLER__
 | ||
| # define declare_symbol_alias_1(symbol, original, type, size) \
 | ||
|    strong_alias (original, symbol); \
 | ||
|    .type C_SYMBOL_NAME (symbol), %##type; \
 | ||
|    .size C_SYMBOL_NAME (symbol), size
 | ||
| #else /* Not __ASSEMBLER__.  */
 | ||
| # define declare_symbol_alias_1(symbol, original, type, size) \
 | ||
|    asm (".globl " __SYMBOL_PREFIX #symbol \
 | ||
| 	"\n\t" declare_symbol_alias_1_alias (symbol, original) \
 | ||
| 	"\n\t.type " __SYMBOL_PREFIX #symbol ", " \
 | ||
| 	"%" #type \
 | ||
| 	"\n\t.size " __SYMBOL_PREFIX #symbol ", " #size);
 | ||
| # ifdef HAVE_ASM_SET_DIRECTIVE
 | ||
| #  define declare_symbol_alias_1_alias(symbol, original) \
 | ||
|      ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX #original
 | ||
| # else
 | ||
| #  define declare_symbol_alias_1_alias(symbol, original) \
 | ||
|      __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX #original
 | ||
| # endif /* HAVE_ASM_SET_DIRECTIVE */
 | ||
| #endif /* __ASSEMBLER__ */
 | ||
| 
 | ||
| 
 | ||
| /*
 | ||
| 
 | ||
| */
 | ||
| 
 | ||
| /* Symbol set support macros.  */
 | ||
| 
 | ||
| /* Make SYMBOL, which is in the text segment, an element of SET.  */
 | ||
| #define text_set_element(set, symbol)	_elf_set_element(set, symbol)
 | ||
| /* Make SYMBOL, which is in the data segment, an element of SET.  */
 | ||
| #define data_set_element(set, symbol)	_elf_set_element(set, symbol)
 | ||
| /* Make SYMBOL, which is in the bss segment, an element of SET.  */
 | ||
| #define bss_set_element(set, symbol)	_elf_set_element(set, symbol)
 | ||
| 
 | ||
| /* These are all done the same way in ELF.
 | ||
|    There is a new section created for each set.  */
 | ||
| #ifdef SHARED
 | ||
| /* When building a shared library, make the set section writable,
 | ||
|    because it will need to be relocated at run time anyway.  */
 | ||
| # define _elf_set_element(set, symbol) \
 | ||
|   static const void *__elf_set_##set##_element_##symbol##__ \
 | ||
|     __attribute__ ((used, section (#set))) = &(symbol)
 | ||
| #else
 | ||
| # define _elf_set_element(set, symbol) \
 | ||
|   static const void *const __elf_set_##set##_element_##symbol##__ \
 | ||
|     __attribute__ ((used, section (#set))) = &(symbol)
 | ||
| #endif
 | ||
| 
 | ||
| /* Define SET as a symbol set.  This may be required (it is in a.out) to
 | ||
|    be able to use the set's contents.  */
 | ||
| #define symbol_set_define(set)	symbol_set_declare(set)
 | ||
| 
 | ||
| /* Declare SET for use in this module, if defined in another module.
 | ||
|    In a shared library, this is always local to that shared object.
 | ||
|    For static linking, the set might be wholly absent and so we use
 | ||
|    weak references.  */
 | ||
| #define symbol_set_declare(set) \
 | ||
|   extern char const __start_##set[] __symbol_set_attribute; \
 | ||
|   extern char const __stop_##set[] __symbol_set_attribute;
 | ||
| #ifdef SHARED
 | ||
| # define __symbol_set_attribute attribute_hidden
 | ||
| #else
 | ||
| # define __symbol_set_attribute __attribute__ ((weak))
 | ||
| #endif
 | ||
| 
 | ||
| /* Return a pointer (void *const *) to the first element of SET.  */
 | ||
| #define symbol_set_first_element(set)	((void *const *) (&__start_##set))
 | ||
| 
 | ||
| /* Return true iff PTR (a void *const *) has been incremented
 | ||
|    past the last element in SET.  */
 | ||
| #define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
 | ||
| 
 | ||
| #if DO_VERSIONING
 | ||
| # define symbol_version(real, name, version) \
 | ||
|      _symbol_version(real, name, version)
 | ||
| # define default_symbol_version(real, name, version) \
 | ||
|      _default_symbol_version(real, name, version)
 | ||
| # ifdef __ASSEMBLER__
 | ||
| #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 | ||
| #   define _symbol_version(real, name, version) \
 | ||
|      .symver real, name##@##version ASM_LINE_SEP			\
 | ||
|      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##version)
 | ||
| #   define _default_symbol_version(real, name, version) \
 | ||
|      .symver real, name##@##@##version ASM_LINE_SEP			\
 | ||
|      .symver C_SYMBOL_DOT_NAME(real), C_SYMBOL_DOT_NAME(name##@##@##version)
 | ||
| #  else
 | ||
| #   define _symbol_version(real, name, version) \
 | ||
|      .symver real, name##@##version
 | ||
| #   define _default_symbol_version(real, name, version) \
 | ||
|      .symver real, name##@##@##version
 | ||
| #  endif
 | ||
| # else
 | ||
| #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 | ||
| #   define _symbol_version(real, name, version) \
 | ||
|      __asm__ (".symver " #real "," #name "@" #version "\n\t"	\
 | ||
| 	      ".symver ." #real ",." #name "@" #version)
 | ||
| #   define _default_symbol_version(real, name, version) \
 | ||
|      __asm__ (".symver " #real "," #name "@@" #version "\n\t"	\
 | ||
| 	      ".symver ." #real ",." #name "@@" #version)
 | ||
| #  else
 | ||
| #   define _symbol_version(real, name, version) \
 | ||
|      __asm__ (".symver " #real "," #name "@" #version)
 | ||
| #   define _default_symbol_version(real, name, version) \
 | ||
|      __asm__ (".symver " #real "," #name "@@" #version)
 | ||
| #  endif
 | ||
| # endif
 | ||
| #else
 | ||
| # define symbol_version(real, name, version)
 | ||
| # define default_symbol_version(real, name, version) \
 | ||
|   strong_alias(real, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined SHARED || defined LIBC_NONSHARED
 | ||
| # define attribute_hidden __attribute__ ((visibility ("hidden")))
 | ||
| #else
 | ||
| # define attribute_hidden
 | ||
| #endif
 | ||
| 
 | ||
| #define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
 | ||
| 
 | ||
| #define attribute_relro __attribute__ ((section (".data.rel.ro")))
 | ||
| 
 | ||
| /* Handling on non-exported internal names.  We have to do this only
 | ||
|    for shared code.  */
 | ||
| #ifdef SHARED
 | ||
| # define INTUSE(name) name##_internal
 | ||
| # define INTDEF(name) strong_alias (name, name##_internal)
 | ||
| # define INTVARDEF(name) \
 | ||
|   _INTVARDEF (name, name##_internal)
 | ||
| # define _INTVARDEF(name, aliasname) \
 | ||
|   extern __typeof (name) aliasname __attribute__ ((alias (#name), \
 | ||
| 						   visibility ("hidden")));
 | ||
| # define INTDEF2(name, newname) strong_alias (name, newname##_internal)
 | ||
| # define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal)
 | ||
| #else
 | ||
| # define INTUSE(name) name
 | ||
| # define INTDEF(name)
 | ||
| # define INTVARDEF(name)
 | ||
| # define INTDEF2(name, newname)
 | ||
| # define INTVARDEF2(name, newname)
 | ||
| #endif
 | ||
| 
 | ||
| /* The following macros are used for PLT bypassing within libc.so
 | ||
|    (and if needed other libraries similarly).
 | ||
|    First of all, you need to have the function prototyped somewhere,
 | ||
|    say in foo/foo.h:
 | ||
| 
 | ||
|    int foo (int __bar);
 | ||
| 
 | ||
|    If calls to foo within libc.so should always go to foo defined in libc.so,
 | ||
|    then in include/foo.h you add:
 | ||
| 
 | ||
|    libc_hidden_proto (foo)
 | ||
| 
 | ||
|    line and after the foo function definition:
 | ||
| 
 | ||
|    int foo (int __bar)
 | ||
|    {
 | ||
|      return __bar;
 | ||
|    }
 | ||
|    libc_hidden_def (foo)
 | ||
| 
 | ||
|    or
 | ||
| 
 | ||
|    int foo (int __bar)
 | ||
|    {
 | ||
|      return __bar;
 | ||
|    }
 | ||
|    libc_hidden_weak (foo)
 | ||
| 
 | ||
|    Similarly for global data.  If references to foo within libc.so should
 | ||
|    always go to foo defined in libc.so, then in include/foo.h you add:
 | ||
| 
 | ||
|    libc_hidden_proto (foo)
 | ||
| 
 | ||
|    line and after foo's definition:
 | ||
| 
 | ||
|    int foo = INITIAL_FOO_VALUE;
 | ||
|    libc_hidden_data_def (foo)
 | ||
| 
 | ||
|    or
 | ||
| 
 | ||
|    int foo = INITIAL_FOO_VALUE;
 | ||
|    libc_hidden_data_weak (foo)
 | ||
| 
 | ||
|    If foo is normally just an alias (strong or weak) to some other function,
 | ||
|    you should use the normal strong_alias first, then add libc_hidden_def
 | ||
|    or libc_hidden_weak:
 | ||
| 
 | ||
|    int baz (int __bar)
 | ||
|    {
 | ||
|      return __bar;
 | ||
|    }
 | ||
|    strong_alias (baz, foo)
 | ||
|    libc_hidden_weak (foo)
 | ||
| 
 | ||
|    If the function should be internal to multiple objects, say ld.so and
 | ||
|    libc.so, the best way is to use:
 | ||
| 
 | ||
|    #if !defined NOT_IN_libc || defined IS_IN_rtld
 | ||
|    hidden_proto (foo)
 | ||
|    #endif
 | ||
| 
 | ||
|    in include/foo.h and the normal macros at all function definitions
 | ||
|    depending on what DSO they belong to.
 | ||
| 
 | ||
|    If versioned_symbol macro is used to define foo,
 | ||
|    libc_hidden_ver macro should be used, as in:
 | ||
| 
 | ||
|    int __real_foo (int __bar)
 | ||
|    {
 | ||
|      return __bar;
 | ||
|    }
 | ||
|    versioned_symbol (libc, __real_foo, foo, GLIBC_2_1);
 | ||
|    libc_hidden_ver (__real_foo, foo)  */
 | ||
| 
 | ||
| #if defined SHARED && defined DO_VERSIONING && !defined NO_HIDDEN
 | ||
| # ifndef __ASSEMBLER__
 | ||
| #  define __hidden_proto_hiddenattr(attrs...) \
 | ||
|   __attribute__ ((visibility ("hidden"), ##attrs))
 | ||
| #  define hidden_proto(name, attrs...) \
 | ||
|   __hidden_proto (name, __GI_##name, ##attrs)
 | ||
| #  define __hidden_proto(name, internal, attrs...) \
 | ||
|   extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
 | ||
|   __hidden_proto_hiddenattr (attrs);
 | ||
| #  define __hidden_asmname(name) \
 | ||
|   __hidden_asmname1 (__USER_LABEL_PREFIX__, name)
 | ||
| #  define __hidden_asmname1(prefix, name) __hidden_asmname2(prefix, name)
 | ||
| #  define __hidden_asmname2(prefix, name) #prefix name
 | ||
| #  define __hidden_ver1(local, internal, name) \
 | ||
|   extern __typeof (name) __EI_##name __asm__(__hidden_asmname (#internal)); \
 | ||
|   extern __typeof (name) __EI_##name \
 | ||
| 	__attribute__((alias (__hidden_asmname (#local))))
 | ||
| #  define hidden_ver(local, name)	__hidden_ver1(local, __GI_##name, name);
 | ||
| #  define hidden_data_ver(local, name)	hidden_ver(local, name)
 | ||
| #  define hidden_def(name)		__hidden_ver1(__GI_##name, name, name);
 | ||
| #  define hidden_data_def(name)		hidden_def(name)
 | ||
| #  define hidden_weak(name) \
 | ||
| 	__hidden_ver1(__GI_##name, name, name) __attribute__((weak));
 | ||
| #  define hidden_data_weak(name)	hidden_weak(name)
 | ||
| #  define hidden_nolink(name, lib, version) \
 | ||
|   __hidden_nolink1 (__GI_##name, __EI_##name, name, VERSION_##lib##_##version)
 | ||
| #  define __hidden_nolink1(local, internal, name, version) \
 | ||
|   __hidden_nolink2 (local, internal, name, version)
 | ||
| #  define __hidden_nolink2(local, internal, name, version) \
 | ||
|   extern __typeof (name) internal __attribute__ ((alias (#local))); \
 | ||
|   __hidden_nolink3 (local, internal, #name "@" #version)
 | ||
| #  define __hidden_nolink3(local, internal, vername) \
 | ||
|   __asm__ (".symver " #internal ", " vername);
 | ||
| # else
 | ||
| /* For assembly, we need to do the opposite of what we do in C:
 | ||
|    in assembly gcc __REDIRECT stuff is not in place, so functions
 | ||
|    are defined by its normal name and we need to create the
 | ||
|    __GI_* alias to it, in C __REDIRECT causes the function definition
 | ||
|    to use __GI_* name and we need to add alias to the real name.
 | ||
|    There is no reason to use hidden_weak over hidden_def in assembly,
 | ||
|    but we provide it for consistency with the C usage.
 | ||
|    hidden_proto doesn't make sense for assembly but the equivalent
 | ||
|    is to call via the HIDDEN_JUMPTARGET macro instead of JUMPTARGET.  */
 | ||
| #  define hidden_def(name)	strong_alias (name, __GI_##name)
 | ||
| #  define hidden_weak(name)	hidden_def (name)
 | ||
| #  define hidden_ver(local, name) strong_alias (local, __GI_##name)
 | ||
| #  define hidden_data_def(name)	strong_data_alias (name, __GI_##name)
 | ||
| #  define hidden_data_weak(name)	hidden_data_def (name)
 | ||
| #  define hidden_data_ver(local, name) strong_data_alias (local, __GI_##name)
 | ||
| #  ifdef HAVE_ASM_GLOBAL_DOT_NAME
 | ||
| #   define HIDDEN_JUMPTARGET(name) .__GI_##name
 | ||
| #  else
 | ||
| #   define HIDDEN_JUMPTARGET(name) __GI_##name
 | ||
| #  endif
 | ||
| # endif
 | ||
| #else
 | ||
| # ifndef __ASSEMBLER__
 | ||
| #  define hidden_proto(name, attrs...)
 | ||
| # else
 | ||
| #  define HIDDEN_JUMPTARGET(name) JUMPTARGET(name)
 | ||
| # endif /* Not  __ASSEMBLER__ */
 | ||
| # define hidden_weak(name)
 | ||
| # define hidden_def(name)
 | ||
| # define hidden_ver(local, name)
 | ||
| # define hidden_data_weak(name)
 | ||
| # define hidden_data_def(name)
 | ||
| # define hidden_data_ver(local, name)
 | ||
| # define hidden_nolink(name, lib, version)
 | ||
| #endif
 | ||
| 
 | ||
| #if !defined NOT_IN_libc
 | ||
| # define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define libc_hidden_def(name) hidden_def (name)
 | ||
| # define libc_hidden_weak(name) hidden_weak (name)
 | ||
| # ifdef LINK_OBSOLETE_RPC
 | ||
|    /* libc_hidden_nolink_sunrpc should only get used in sunrpc code.  */
 | ||
| #  define libc_hidden_nolink_sunrpc(name, version) hidden_def (name)
 | ||
| # else
 | ||
| #  define libc_hidden_nolink_sunrpc(name, version) hidden_nolink (name, libc, version)
 | ||
| # endif
 | ||
| # define libc_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define libc_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define libc_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define libc_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define libc_hidden_proto(name, attrs...)
 | ||
| # define libc_hidden_def(name)
 | ||
| # define libc_hidden_weak(name)
 | ||
| # define libc_hidden_ver(local, name)
 | ||
| # define libc_hidden_data_def(name)
 | ||
| # define libc_hidden_data_weak(name)
 | ||
| # define libc_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_rtld
 | ||
| # define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define rtld_hidden_def(name) hidden_def (name)
 | ||
| # define rtld_hidden_weak(name) hidden_weak (name)
 | ||
| # define rtld_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define rtld_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define rtld_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define rtld_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define rtld_hidden_proto(name, attrs...)
 | ||
| # define rtld_hidden_def(name)
 | ||
| # define rtld_hidden_weak(name)
 | ||
| # define rtld_hidden_ver(local, name)
 | ||
| # define rtld_hidden_data_def(name)
 | ||
| # define rtld_hidden_data_weak(name)
 | ||
| # define rtld_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_libm
 | ||
| # define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define libm_hidden_def(name) hidden_def (name)
 | ||
| # define libm_hidden_weak(name) hidden_weak (name)
 | ||
| # define libm_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define libm_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define libm_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define libm_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define libm_hidden_proto(name, attrs...)
 | ||
| # define libm_hidden_def(name)
 | ||
| # define libm_hidden_weak(name)
 | ||
| # define libm_hidden_ver(local, name)
 | ||
| # define libm_hidden_data_def(name)
 | ||
| # define libm_hidden_data_weak(name)
 | ||
| # define libm_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_libresolv
 | ||
| # define libresolv_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define libresolv_hidden_def(name) hidden_def (name)
 | ||
| # define libresolv_hidden_weak(name) hidden_weak (name)
 | ||
| # define libresolv_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define libresolv_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define libresolv_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define libresolv_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define libresolv_hidden_proto(name, attrs...)
 | ||
| # define libresolv_hidden_def(name)
 | ||
| # define libresolv_hidden_weak(name)
 | ||
| # define libresolv_hidden_ver(local, name)
 | ||
| # define libresolv_hidden_data_def(name)
 | ||
| # define libresolv_hidden_data_weak(name)
 | ||
| # define libresolv_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_librt
 | ||
| # define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define librt_hidden_def(name) hidden_def (name)
 | ||
| # define librt_hidden_weak(name) hidden_weak (name)
 | ||
| # define librt_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define librt_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define librt_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define librt_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define librt_hidden_proto(name, attrs...)
 | ||
| # define librt_hidden_def(name)
 | ||
| # define librt_hidden_weak(name)
 | ||
| # define librt_hidden_ver(local, name)
 | ||
| # define librt_hidden_data_def(name)
 | ||
| # define librt_hidden_data_weak(name)
 | ||
| # define librt_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_libdl
 | ||
| # define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define libdl_hidden_def(name) hidden_def (name)
 | ||
| # define libdl_hidden_weak(name) hidden_weak (name)
 | ||
| # define libdl_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define libdl_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define libdl_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define libdl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define libdl_hidden_proto(name, attrs...)
 | ||
| # define libdl_hidden_def(name)
 | ||
| # define libdl_hidden_weak(name)
 | ||
| # define libdl_hidden_ver(local, name)
 | ||
| # define libdl_hidden_data_def(name)
 | ||
| # define libdl_hidden_data_weak(name)
 | ||
| # define libdl_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_libnss_files
 | ||
| # define libnss_files_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define libnss_files_hidden_def(name) hidden_def (name)
 | ||
| # define libnss_files_hidden_weak(name) hidden_weak (name)
 | ||
| # define libnss_files_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define libnss_files_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define libnss_files_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define libnss_files_hidden_data_ver(local, name) hidden_data_ver(local, name)
 | ||
| #else
 | ||
| # define libnss_files_hidden_proto(name, attrs...)
 | ||
| # define libnss_files_hidden_def(name)
 | ||
| # define libnss_files_hidden_weak(name)
 | ||
| # define libnss_files_hidden_ver(local, name)
 | ||
| # define libnss_files_hidden_data_def(name)
 | ||
| # define libnss_files_hidden_data_weak(name)
 | ||
| # define libnss_files_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_libnsl
 | ||
| # define libnsl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define libnsl_hidden_def(name) hidden_def (name)
 | ||
| # define libnsl_hidden_weak(name) hidden_weak (name)
 | ||
| # define libnsl_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define libnsl_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define libnsl_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define libnsl_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define libnsl_hidden_proto(name, attrs...)
 | ||
| # define libnsl_hidden_def(name)
 | ||
| # define libnsl_hidden_weak(name)
 | ||
| # define libnsl_hidden_ver(local, name)
 | ||
| # define libnsl_hidden_data_def(name)
 | ||
| # define libnsl_hidden_data_weak(name)
 | ||
| # define libnsl_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_libnss_nisplus
 | ||
| # define libnss_nisplus_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define libnss_nisplus_hidden_def(name) hidden_def (name)
 | ||
| # define libnss_nisplus_hidden_weak(name) hidden_weak (name)
 | ||
| # define libnss_nisplus_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define libnss_nisplus_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define libnss_nisplus_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define libnss_nisplus_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define libnss_nisplus_hidden_proto(name, attrs...)
 | ||
| # define libnss_nisplus_hidden_def(name)
 | ||
| # define libnss_nisplus_hidden_weak(name)
 | ||
| # define libnss_nisplus_hidden_ver(local, name)
 | ||
| # define libnss_nisplus_hidden_data_def(name)
 | ||
| # define libnss_nisplus_hidden_data_weak(name)
 | ||
| # define libnss_nisplus_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| #define libc_hidden_builtin_proto(name, attrs...) libc_hidden_proto (name, ##attrs)
 | ||
| #define libc_hidden_builtin_def(name) libc_hidden_def (name)
 | ||
| #define libc_hidden_builtin_weak(name) libc_hidden_weak (name)
 | ||
| #define libc_hidden_builtin_ver(local, name) libc_hidden_ver (local, name)
 | ||
| #ifdef __ASSEMBLER__
 | ||
| # define HIDDEN_BUILTIN_JUMPTARGET(name) HIDDEN_JUMPTARGET(name)
 | ||
| #endif
 | ||
| 
 | ||
| #if defined NOT_IN_libc && defined IS_IN_libutil
 | ||
| # define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
 | ||
| # define libutil_hidden_def(name) hidden_def (name)
 | ||
| # define libutil_hidden_weak(name) hidden_weak (name)
 | ||
| # define libutil_hidden_ver(local, name) hidden_ver (local, name)
 | ||
| # define libutil_hidden_data_def(name) hidden_data_def (name)
 | ||
| # define libutil_hidden_data_weak(name) hidden_data_weak (name)
 | ||
| # define libutil_hidden_data_ver(local, name) hidden_data_ver (local, name)
 | ||
| #else
 | ||
| # define libutil_hidden_proto(name, attrs...)
 | ||
| # define libutil_hidden_def(name)
 | ||
| # define libutil_hidden_weak(name)
 | ||
| # define libutil_hidden_ver(local, name)
 | ||
| # define libutil_hidden_data_def(name)
 | ||
| # define libutil_hidden_data_weak(name)
 | ||
| # define libutil_hidden_data_ver(local, name)
 | ||
| #endif
 | ||
| 
 | ||
| /* Get some dirty hacks.  */
 | ||
| #include <symbol-hacks.h>
 | ||
| 
 | ||
| /* Move compatibility symbols out of the way by placing them all in a
 | ||
|    special section.  */
 | ||
| #ifndef __ASSEMBLER__
 | ||
| # define attribute_compat_text_section \
 | ||
|     __attribute__ ((section (".text.compat")))
 | ||
| # define attribute_compat_data_section \
 | ||
|     __attribute__ ((section (".data.compat")))
 | ||
| #else
 | ||
| # define compat_text_section .section ".text.compat", "ax";
 | ||
| # define compat_data_section .section ".data.compat", "aw";
 | ||
| #endif
 | ||
| 
 | ||
| /* Marker used for indirection function symbols.  */
 | ||
| #define libc_ifunc(name, expr)						\
 | ||
|   extern void *name##_ifunc (void) __asm__ (#name);			\
 | ||
|   void *name##_ifunc (void)						\
 | ||
|   {									\
 | ||
|     INIT_ARCH ();							\
 | ||
|     __typeof (name) *res = expr;					\
 | ||
|     return res;								\
 | ||
|   }									\
 | ||
|   __asm__ (".type " #name ", %gnu_indirect_function");
 | ||
| 
 | ||
| /* The body of the function is supposed to use __get_cpu_features
 | ||
|    which will, if necessary, initialize the data first.  */
 | ||
| #define libm_ifunc(name, expr)						\
 | ||
|   extern void *name##_ifunc (void) __asm__ (#name);			\
 | ||
|   void *name##_ifunc (void)						\
 | ||
|   {									\
 | ||
|     __typeof (name) *res = expr;					\
 | ||
|     return res;								\
 | ||
|   }									\
 | ||
|   __asm__ (".type " #name ", %gnu_indirect_function");
 | ||
| 
 | ||
| #ifdef HAVE_ASM_SET_DIRECTIVE
 | ||
| # define libc_ifunc_hidden_def1(local, name)				\
 | ||
|     __asm__ (".globl " #local "\n\t"					\
 | ||
| 	     ".hidden " #local "\n\t"					\
 | ||
| 	     ".set " #local ", " #name);
 | ||
| #else
 | ||
| # define libc_ifunc_hidden_def1(local, name)				\
 | ||
|     __asm__ (".globl " #local "\n\t"					\
 | ||
| 	     ".hidden " #local "\n\t"					\
 | ||
| 	     #local " = " #name);
 | ||
| #endif
 | ||
| 
 | ||
| #define libc_ifunc_hidden_def(name) \
 | ||
|   libc_ifunc_hidden_def1 (__GI_##name, name)
 | ||
| 
 | ||
| #endif /* libc-symbols.h */
 |