/* Support macros for making weak and strong aliases for symbols,
and for using symbol sets and linker warnings with GNU ld.
- Copyright (C) 1995-1998,2000-2003,2004 Free Software Foundation, Inc.
+ Copyright (C) 1995-2019 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
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, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
+ License along with the GNU C Library; if not, see
+ <https://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.
+/* This file is included implicitly in the compilation of every source file,
+ using -include. It includes config.h. */
- We include config.h which is generated by configure.
- It should define for us the following symbols:
+/* Enable declarations of GNU extensions, since we are compiling them. */
+#define _GNU_SOURCE 1
+
+#ifdef MODULE_NAME
+
+/* Use `#if IS_IN (module)` to detect what component is being compiled. */
+#define PASTE_NAME1(a,b) a##b
+#define PASTE_NAME(a,b) PASTE_NAME1 (a,b)
+#define IN_MODULE PASTE_NAME (MODULE_, MODULE_NAME)
+#define IS_IN(lib) (IN_MODULE == MODULE_##lib)
+
+/* True if the current module is a versioned library. Versioned
+ library names culled from shlib-versions files are assigned a
+ MODULE_* value greater than MODULE_LIBS_BEGIN. */
+#define IS_IN_LIB (IN_MODULE > MODULE_LIBS_BEGIN)
+
+/* The testsuite, and some other ancillary code, should be compiled against
+ as close an approximation to the installed headers as possible.
+ Defining this symbol disables most internal-use-only declarations
+ provided by this header, and all those provided by other internal
+ wrapper headers. */
+#if IS_IN (testsuite) || defined IS_IN_build || defined __cplusplus
+# define _ISOMAC 1
+#endif
- * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'.
- * ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'.
- * ASM_TYPE_DIRECTIVE_PREFIX with `@' or `#' or whatever for .type,
- or leave it undefined if there is no .type directive.
- * HAVE_GNU_LD if using GNU ld, with support for weak symbols in a.out,
- and for symbol set and warning messages extensions in a.out and ELF.
- * HAVE_ELF if using ELF, which supports weak symbols using `.weak'.
- * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'.
- * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'.
+#else
+/* The generation process for a few files created very early in the
+ build (notably libc-modules.h itself) involves preprocessing this
+ header without defining MODULE_NAME. Under these conditions,
+ internal declarations (especially from config.h) must be visible,
+ but IS_IN should always evaluate as false. */
+# define IS_IN(lib) 0
+# define IS_IN_LIB 0
+# define IN_MODULE (-1)
+#endif
- */
+#ifndef _ISOMAC
/* 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,
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
+/* Some files must be compiled with optimization on. */
+#if !defined __ASSEMBLER__ && !defined __OPTIMIZE__
+# error "glibc cannot be compiled without optimization"
+#endif
-#include <config.h>
+/* -ffast-math cannot be applied to the C library, as it alters the ABI.
+ Some test components that use -ffast-math are currently not part of
+ IS_IN (testsuite) for technical reasons, so we have a secondary override. */
+#if defined __FAST_MATH__ && !defined TEST_FAST_MATH
+# error "glibc must not be compiled with -ffast-math"
+#endif
-/* The symbols in all the user (non-_) macros are C symbols.
- HAVE_GNU_LD without HAVE_ELF implies a.out. */
+#include <config.h>
-#if defined HAVE_ASM_WEAK_DIRECTIVE || defined HAVE_ASM_WEAKEXT_DIRECTIVE
-# define HAVE_WEAK_SYMBOLS
+/* When PIC is defined and SHARED isn't defined, we are building PIE
+ by default. */
+#if defined PIC && !defined SHARED
+# define BUILD_PIE_DEFAULT 1
+#else
+# define BUILD_PIE_DEFAULT 0
#endif
+/* Define this for the benefit of portable GNU code that wants to check it.
+ Code that checks with #if will not #include <config.h> again, since we've
+ already done it (and this file is implicitly included in every compile,
+ via -include). Code that checks with #ifdef will #include <config.h>,
+ but that file should always be idempotent (i.e., it's just #define/#undef
+ and nothing else anywhere should be changing the macro state it touches),
+ so it's harmless. */
+#define HAVE_CONFIG_H 0
+
+/* Define these macros for the benefit of portable GNU code that wants to check
+ them. Of course, STDC_HEADERS is never false when building libc! */
+#define STDC_HEADERS 1
+#define HAVE_MBSTATE_T 1
+#define HAVE_MBSRTOWCS 1
+#define HAVE_LIBINTL_H 1
+#define HAVE_WCTYPE_H 1
+#define HAVE_ISWCTYPE 1
+#define ENABLE_NLS 1
+
+/* The symbols in all the user (non-_) macros are C symbols. */
+
#ifndef __SYMBOL_PREFIX
-# ifdef NO_UNDERSCORES
-# define __SYMBOL_PREFIX
-# else
-# define __SYMBOL_PREFIX "_"
-# endif
+# define __SYMBOL_PREFIX
#endif
#ifndef C_SYMBOL_NAME
-# ifdef NO_UNDERSCORES
-# define C_SYMBOL_NAME(name) name
-# else
-# define C_SYMBOL_NAME(name) _##name
-# endif
+# 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
+#ifndef __attribute_copy__
+/* Provide an empty definition when cdefs.h is not included. */
+# define __attribute_copy__(arg)
#endif
#ifndef __ASSEMBLER__
/* 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)));
+ extern __typeof (name) aliasname __attribute__ ((alias (#name))) \
+ __attribute_copy__ (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__))
-# ifdef HAVE_WEAK_SYMBOLS
-
/* 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)));
+# define weak_alias(name, aliasname) _weak_alias (name, aliasname)
+# define _weak_alias(name, aliasname) \
+ extern __typeof (name) aliasname __attribute__ ((weak, alias (#name))) \
+ __attribute_copy__ (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"))) \
+ __attribute_copy__ (name);
/* 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
-
-# define weak_alias(name, aliasname) strong_alias(name, aliasname)
-# define weak_extern(symbol) /* Nothing. */
-
+# define weak_extern(symbol) _weak_extern (weak symbol)
+# define _weak_extern(expr) _Pragma (#expr)
+
+/* In shared builds, the expression call_function_static_weak
+ (FUNCTION-SYMBOL, ARGUMENTS) invokes FUNCTION-SYMBOL (an
+ identifier) unconditionally, with the (potentially empty) argument
+ list ARGUMENTS. In static builds, if FUNCTION-SYMBOL has a
+ definition, the function is invoked as before; if FUNCTION-SYMBOL
+ is NULL, no call is performed. */
+# ifdef SHARED
+# define call_function_static_weak(func, ...) func (__VA_ARGS__)
+# else /* !SHARED */
+# define call_function_static_weak(func, ...) \
+ ({ \
+ extern __typeof__ (func) func weak_function; \
+ (func != NULL ? func (__VA_ARGS__) : (void)0); \
+ })
# endif
#else /* __ASSEMBLER__ */
# ifdef HAVE_ASM_SET_DIRECTIVE
-# ifdef HAVE_ASM_GLOBAL_DOT_NAME
-# define strong_alias(original, alias) \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
- .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) ASM_LINE_SEP \
- ASM_GLOBAL_DIRECTIVE 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) \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
- .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
-# else
-# define strong_alias(original, alias) \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
+# 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
+# define strong_data_alias(original, alias) strong_alias(original, alias)
# else
-# ifdef HAVE_ASM_GLOBAL_DOT_NAME
-# define strong_alias(original, alias) \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
- C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) ASM_LINE_SEP \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \
- C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
-# define strong_data_alias(original, alias) \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
+# define strong_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) \
- ASM_GLOBAL_DIRECTIVE 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
+# define strong_data_alias(original, alias) strong_alias(original, alias)
# endif
-# ifdef HAVE_WEAK_SYMBOLS
-# 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) \
+# 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) \
+# define weak_extern(symbol) \
.weak C_SYMBOL_NAME (symbol)
-# endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
-
-# else /* ! HAVE_WEAK_SYMBOLS */
-
-# define weak_alias(original, alias) strong_alias(original, alias)
-# define weak_extern(symbol) /* Nothing */
-# endif /* ! HAVE_WEAK_SYMBOLS */
-
#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
-
-/* Prepare for the case that `__builtin_expect' is not available. */
-#ifndef HAVE_BUILTIN_EXPECT
-# define __builtin_expect(expr, val) (expr)
-#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. */
-#ifdef HAVE_GNU_LD
-# ifdef HAVE_ELF
-
/* We want the .gnu.warning.SYMBOL section to be unallocated. */
-# ifdef HAVE_ASM_PREVIOUS_DIRECTIVE
-# define __make_section_unallocated(section_string) \
+#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) \
+#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")))
-# else /* Not ELF: a.out */
-# ifdef HAVE_XCOFF
-/* XCOFF does not support .stabs.
- The native aix linker will remove the .stab and .stabstr sections
- The gnu linker will have a fatal error if there is a relocation for
- symbol in the .stab section. Silently disable this macro. */
-# define link_warning(symbol, msg)
-# else
-# define link_warning(symbol, msg) \
- asm (".stabs \"" msg "\",30,0,0,0\n\t" \
- ".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n");
-# endif /* XCOFF */
-# define libc_freeres_ptr(decl) decl
-# define __libc_freeres_fn_section
-# endif
-#else
-/* We will never be heard; they will all die horribly. */
-# define link_warning(symbol, msg)
-# define libc_freeres_ptr(decl) decl
-# define __libc_freeres_fn_section
-#endif
-#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) \
- link_warning (name, \
- "warning: " #name " is not implemented and will always fail")
+ __make_section_unallocated (".gnu.glibc-stub." #name) \
+ link_warning (name, #name " is not implemented and will always fail")
/* Warning for linking functions calling dlopen into static binaries. */
#ifdef SHARED
for linking")
#endif
-/* Declare SYMBOL to be TYPE (`function' or `object') and of SIZE bytes,
- when the assembler supports such declarations (such as in ELF).
+/* Resource Freeing Hooks:
+
+ Normally a process exits and the OS cleans up any allocated
+ memory. However, when tooling like mtrace or valgrind is monitoring
+ the process we need to free all resources that are part of the
+ process in order to provide the consistency required to track
+ memory leaks.
+
+ A single public API exists and is __libc_freeres(), and this is used
+ by applications like valgrind to freee resouces.
+
+ There are 3 cases:
+
+ (a) __libc_freeres
+
+ In this case all you need to do is define the freeing routine:
+
+ foo.c:
+ libfoo_freeres_fn (foo_freeres)
+ {
+ complex_free (mem);
+ }
+
+ This ensures the function is called at the right point to free
+ resources.
+
+ (b) __libc_freeres_ptr
+
+ The framework for (a) iterates over the list of pointers-to-free
+ in (b) and frees them.
+
+ foo.c:
+ libc_freeres_ptr (static char *foo_buffer);
+
+ Freeing these resources alaways happens last and is equivalent
+ to registering a function that does 'free (foo_buffer)'.
+
+ (c) Explicit lists of free routines to call or objects to free.
+
+ It is the intended goal to remove (a) and (b) which have some
+ non-determinism based on link order, and instead use explicit
+ lists of functions and frees to resolve cleanup ordering issues
+ and make it easy to debug and maintain.
+
+ As of today the following subsystems use (c):
+
+ Per-thread cleanup:
+ * malloc/thread-freeres.c
+
+ libdl cleanup:
+ * dlfcn/dlfreeres.c
+
+ libpthread cleanup:
+ * nptl/nptlfreeres.c
+
+ So if you need any shutdown routines to run you should add them
+ directly to the appropriate subsystem's shutdown list. */
+
+/* Resource pointers to free in libc.so. */
+#define libc_freeres_ptr(decl) \
+ __make_section_unallocated ("__libc_freeres_ptrs, \"aw\", %nobits") \
+ decl __attribute__ ((section ("__libc_freeres_ptrs" __sec_comment)))
+
+/* Resource freeing functions from libc.so go in this section. */
+#define __libc_freeres_fn_section \
+ __attribute__ ((section ("__libc_freeres_fn")))
+
+/* Resource freeing functions for libc.so. */
+#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)
+
+/* 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(symbol, type, size) \
- declare_symbol_1 (symbol, type, size)
-#ifdef ASM_TYPE_DIRECTIVE_PREFIX
-# ifdef __ASSEMBLER__
-# define declare_symbol_1(symbol, type, size) \
- .type C_SYMBOL_NAME (symbol), \
- declare_symbol_1_paste (ASM_TYPE_DIRECTIVE_PREFIX, type), size
-# define declare_symbol_1_paste(a, b) declare_symbol_1_paste_1 (a,b)
-# define declare_symbol_1_paste_1(a,b) a##b
-# else /* Not __ASSEMBLER__. */
-# define declare_symbol_1(symbol, type, size) \
- asm (".type " __SYMBOL_PREFIX #symbol ", " \
- declare_symbol_1_stringify (ASM_TYPE_DIRECTIVE_PREFIX) #type \
- "\n\t.size " __SYMBOL_PREFIX #symbol ", " #size);
-# define declare_symbol_1_stringify(x) declare_symbol_1_stringify_1 (x)
-# define declare_symbol_1_stringify_1(x) #x
-# endif /* __ASSEMBLER__ */
-#else
-# define declare_symbol_1(symbol, type, size) /* Nothing. */
-#endif
+#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__ */
/*
\f
*/
-#ifdef HAVE_GNU_LD
-
/* Symbol set support macros. */
-# ifdef HAVE_ELF
-
/* Make SYMBOL, which is in the text segment, an element of SET. */
-# define text_set_element(set, symbol) _elf_set_element(set, symbol)
+#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)
+#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)
+#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
+#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) \
+# 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) \
+#else
+# define _elf_set_element(set, symbol) \
static const void *const __elf_set_##set##_element_##symbol##__ \
__attribute__ ((used, section (#set))) = &(symbol)
-# endif
+#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)
+#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) \
+#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
+#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))
+#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)
-
-# else /* Not ELF: a.out. */
-
-# ifdef HAVE_XCOFF
-/* XCOFF does not support .stabs.
- The native aix linker will remove the .stab and .stabstr sections
- The gnu linker will have a fatal error if there is a relocation for
- symbol in the .stab section. Silently disable these macros. */
-# define text_set_element(set, symbol)
-# define data_set_element(set, symbol)
-# define bss_set_element(set, symbol)
-# else
-# define text_set_element(set, symbol) \
- asm (".stabs \"" __SYMBOL_PREFIX #set "\",23,0,0," __SYMBOL_PREFIX #symbol)
-# define data_set_element(set, symbol) \
- asm (".stabs \"" __SYMBOL_PREFIX #set "\",25,0,0," __SYMBOL_PREFIX #symbol)
-# define bss_set_element(set, symbol) ?error Must use initialized data.
-# endif /* XCOFF */
-# define symbol_set_define(set) void *const (set)[1];
-# define symbol_set_declare(set) extern void *const (set)[1];
-
-# define symbol_set_first_element(set) &(set)[1]
-# define symbol_set_end_p(set, ptr) (*(ptr) == 0)
-
-# endif /* ELF. */
-#else
-/* We cannot do anything in generial. */
-# define text_set_element(set, symbol) asm ("")
-# define data_set_element(set, symbol) asm ("")
-# define bss_set_element(set, symbol) asm ("")
-# define symbol_set_define(set) void *const (set)[1];
-# define symbol_set_declare(set) extern void *const (set)[1];
-
-# define symbol_set_first_element(set) &(set)[1]
-# define symbol_set_end_p(set, ptr) (*(ptr) == 0)
-#endif /* Have GNU ld. */
-
-#if DO_VERSIONING
+#define symbol_set_end_p(set, ptr) ((ptr) >= (void *const *) &__stop_##set)
+
+/* Use symbol_version_reference to specify the version a symbol
+ reference should link to. Use symbol_version or
+ default_symbol_version for the definition of a versioned symbol.
+ The difference is that the latter is a no-op in non-shared
+ builds. */
+#ifdef __ASSEMBLER__
+# define symbol_version_reference(real, name, version) \
+ .symver real, name##@##version
+#else /* !__ASSEMBLER__ */
+# define symbol_version_reference(real, name, version) \
+ __asm__ (".symver " #real "," #name "@" #version)
+#endif
+
+#ifdef SHARED
# define symbol_version(real, name, version) \
- _symbol_version(real, name, version)
+ symbol_version_reference(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) \
+# 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) \
+# define _default_symbol_version(real, name, version) \
__asm__ (".symver " #real "," #name "@@" #version)
-# endif
# endif
#else
# define symbol_version(real, name, version)
strong_alias(real, name)
#endif
-#if defined HAVE_VISIBILITY_ATTRIBUTE \
- && (defined SHARED || defined LIBC_NONSHARED)
+#if defined SHARED || defined LIBC_NONSHARED \
+ || (BUILD_PIE_DEFAULT && IS_IN (libc))
# define attribute_hidden __attribute__ ((visibility ("hidden")))
#else
# define attribute_hidden
#endif
-#ifdef HAVE_TLS_MODEL_ATTRIBUTE
-# define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
-#else
-# define attribute_tls_model_ie
-#endif
+#define attribute_tls_model_ie __attribute__ ((tls_model ("initial-exec")))
-#ifdef HAVE_Z_RELRO
-# define attribute_relro __attribute__ ((section (".data.rel.ro")))
-#else
-# define attribute_relro
-#endif
+#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)
-# if defined HAVE_VISIBILITY_ATTRIBUTE
-# define _INTVARDEF(name, aliasname) \
- extern __typeof (name) aliasname __attribute__ ((alias (#name), \
- visibility ("hidden")));
-# else
-# define _INTVARDEF(name, aliasname) \
- extern __typeof (name) aliasname __attribute__ ((alias (#name)));
-# endif
-# define INTDEF2(name, newname) strong_alias (name, newname##_internal)
-# define INTVARDEF2(name, newname) _INTVARDEF (name, newname##_internal)
+
+/* Used to disable stack protection in sensitive places, like ifunc
+ resolvers and early static TLS init. */
+#ifdef HAVE_CC_NO_STACK_PROTECTOR
+# define inhibit_stack_protector \
+ __attribute__ ((__optimize__ ("-fno-stack-protector")))
#else
-# define INTUSE(name) name
-# define INTDEF(name)
-# define INTVARDEF(name)
-# define INTDEF2(name, newname)
-# define INTVARDEF2(name, newname)
+# define inhibit_stack_protector
#endif
/* The following macros are used for PLT bypassing within libc.so
}
libc_hidden_weak (foo)
- Simularly for global data. If references to foo within libc.so should
+ 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)
int foo = INITIAL_FOO_VALUE;
libc_hidden_data_weak (foo)
- If foo is normally just an alias (strong or weak) of some other function,
+ 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:
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
+ #if IS_IN (libc) || IS_IN (rtld)
hidden_proto (foo)
#endif
versioned_symbol (libc, __real_foo, foo, GLIBC_2_1);
libc_hidden_ver (__real_foo, foo) */
-#if defined SHARED && defined DO_VERSIONING \
- && !defined HAVE_BROKEN_ALIAS_ATTRIBUTE && !defined NO_HIDDEN
+#if defined SHARED && !defined NO_HIDDEN
# ifndef __ASSEMBLER__
-# if !defined HAVE_VISIBILITY_ATTRIBUTE \
- || defined HAVE_BROKEN_VISIBILITY_ATTRIBUTE
-# define __hidden_proto_hiddenattr(attrs...)
-# else
-# define __hidden_proto_hiddenattr(attrs...) \
+# define __hidden_proto_hiddenattr(attrs...) \
__attribute__ ((visibility ("hidden"), ##attrs))
-# endif
# define hidden_proto(name, attrs...) \
- __hidden_proto (name, __GI_##name, ##attrs)
-# define __hidden_proto(name, internal, attrs...) \
- extern __typeof (name) internal; \
- extern __typeof (name) name __asm__ (__hidden_asmname (#internal)) \
+ __hidden_proto (name, , __GI_##name, ##attrs)
+# define hidden_tls_proto(name, attrs...) \
+ __hidden_proto (name, __thread, __GI_##name, ##attrs)
+# define __hidden_proto(name, thread, internal, attrs...) \
+ extern thread __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
-# ifdef HAVE_ASM_SET_DIRECTIVE
-# define __hidden_def1(original, alias) \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
- .set C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
-# ifdef HAVE_ASM_GLOBAL_DOT_NAME
-# define __hidden_dot_def1(original, alias) ASM_LINE_SEP \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \
- .set C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
-# else
-# define __hidden_dot_def1(original, alias)
-# endif
-# else
-# define __hidden_def1(original, alias) \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias) ASM_LINE_SEP \
- C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
-# ifdef HAVE_ASM_GLOBAL_DOT_NAME
-# define __hidden_dot_def1(original, alias) ASM_LINE_SEP \
- ASM_GLOBAL_DIRECTIVE C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \
- C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
-# else
-# define __hidden_dot_def1(original, alias)
-# endif
-# endif
-# define __hidden_def2(...) #__VA_ARGS__
-# define __hidden_def3(...) __hidden_def2 (__VA_ARGS__)
-# define hidden_def(name) \
- __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name) \
- __hidden_dot_def1 (__GI_##name, name)));
-# define hidden_data_def(name) \
- __asm__ (__hidden_def3 (__hidden_def1 (__GI_##name, name)));
-# define hidden_ver(local, name) \
- __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name) \
- __hidden_dot_def1 (local, __GI_##name)));
-# define hidden_data_ver(local, name) \
- __asm__ (__hidden_def3 (__hidden_def1 (local, __GI_##name)));
-# ifdef HAVE_WEAK_SYMBOLS
-# ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
-# define __hidden_weak1(original, alias) \
- .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
-# ifdef HAVE_ASM_GLOBAL_DOT_NAME
-# define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \
- .weakext C_SYMBOL_DOT_NAME (alias), C_SYMBOL_DOT_NAME (original)
-# else
-# define __hidden_dot_weak1(original, alias)
-# endif
-# else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
-# define __hidden_weak1(original, alias) \
- .weak C_SYMBOL_NAME (alias) ASM_LINE_SEP \
- C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
-# ifdef HAVE_ASM_GLOBAL_DOT_NAME
-# define __hidden_dot_weak1(original, alias) ASM_LINE_SEP \
- .weak C_SYMBOL_DOT_NAME (alias) ASM_LINE_SEP \
- C_SYMBOL_DOT_NAME (alias) = C_SYMBOL_DOT_NAME (original)
-# else
-# define __hidden_dot_weak1(original, alias)
-# endif
-# endif
-# define hidden_weak(name) \
- __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name) \
- __hidden_dot_weak1 (__GI_##name, name)));
-# define hidden_data_weak(name) \
- __asm__ (__hidden_def3 (__hidden_weak1 (__GI_##name, name)));
-# else
-# define hidden_weak(name) hidden_def (name)
-# endif
+# define __hidden_ver1(local, internal, name) \
+ __hidden_ver2 (, local, internal, name)
+# define __hidden_ver2(thread, local, internal, name) \
+ extern thread __typeof (name) __EI_##name \
+ __asm__(__hidden_asmname (#internal)); \
+ extern thread __typeof (name) __EI_##name \
+ __attribute__((alias (__hidden_asmname (#local)))) \
+ __attribute_copy__ (name)
+# 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_tls_def(name) \
+ __hidden_ver2 (__thread, __GI_##name, name, 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))) \
+ __attribute_copy__ (name); \
+ __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
# 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_tls_def(name) hidden_data_def (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
+# define HIDDEN_JUMPTARGET(name) __GI_##name
# endif
#else
# ifndef __ASSEMBLER__
-# define hidden_proto(name, attrs...)
+# if !defined SHARED && IS_IN (libc) && !defined LIBC_NONSHARED \
+ && (!defined PIC || !defined NO_HIDDEN_EXTERN_FUNC_IN_PIE) \
+ && !defined NO_HIDDEN
+# define __hidden_proto_hiddenattr(attrs...) \
+ __attribute__ ((visibility ("hidden"), ##attrs))
+# define hidden_proto(name, attrs...) \
+ __hidden_proto (name, , name, ##attrs)
+# define hidden_tls_proto(name, attrs...) \
+ __hidden_proto (name, __thread, name, ##attrs)
+# define __hidden_proto(name, thread, internal, attrs...) \
+ extern thread __typeof (name) name __hidden_proto_hiddenattr (attrs);
+# else
+# define hidden_proto(name, attrs...)
+# define hidden_tls_proto(name, attrs...)
+# endif
# else
# define HIDDEN_JUMPTARGET(name) JUMPTARGET(name)
# endif /* Not __ASSEMBLER__ */
# define hidden_ver(local, name)
# define hidden_data_weak(name)
# define hidden_data_def(name)
+# define hidden_tls_def(name)
# define hidden_data_ver(local, name)
+# define hidden_nolink(name, lib, version)
#endif
-#if !defined NOT_IN_libc
+#if IS_IN (libc)
# define libc_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libc_hidden_tls_proto(name, attrs...) hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_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
+#if IS_IN (rtld) && !defined NO_RTLD_HIDDEN
# define rtld_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define rtld_hidden_tls_proto(name, attrs...) hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_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
+#if IS_IN (libm)
# define libm_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libm_hidden_tls_proto(name, attrs...) hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_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
+#if IS_IN (libmvec)
+# define libmvec_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libmvec_hidden_tls_proto(name, attrs...) hidden_tls_proto (name, ##attrs)
+# define libmvec_hidden_def(name) hidden_def (name)
+# define libmvec_hidden_weak(name) hidden_weak (name)
+# define libmvec_hidden_ver(local, name) hidden_ver (local, name)
+# define libmvec_hidden_data_def(name) hidden_data_def (name)
+# define libmvec_hidden_tls_def(name) hidden_tls_def (name)
+# define libmvec_hidden_data_weak(name) hidden_data_weak (name)
+# define libmvec_hidden_data_ver(local, name) hidden_data_ver (local, name)
+#else
+# define libmvec_hidden_proto(name, attrs...)
+# define libmvec_hidden_tls_proto(name, attrs...)
+# define libmvec_hidden_def(name)
+# define libmvec_hidden_weak(name)
+# define libmvec_hidden_ver(local, name)
+# define libmvec_hidden_data_def(name)
+# define libmvec_hidden_tls_def(name)
+# define libmvec_hidden_data_weak(name)
+# define libmvec_hidden_data_ver(local, name)
+#endif
+
+#if IS_IN (libresolv)
# define libresolv_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libresolv_hidden_tls_proto(name, attrs...) \
+ hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_def(name)
# define libresolv_hidden_data_weak(name)
# define libresolv_hidden_data_ver(local, name)
#endif
-#if defined NOT_IN_libc && defined IS_IN_libdl
+#if IS_IN (librt)
+# define librt_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define librt_hidden_tls_proto(name, attrs...) \
+ hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_def(name)
+# define librt_hidden_data_weak(name)
+# define librt_hidden_data_ver(local, name)
+#endif
+
+#if IS_IN (libdl)
# define libdl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libdl_hidden_tls_proto(name, attrs...) \
+ hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_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
+#if IS_IN (libnss_files)
# define libnss_files_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libnss_files_hidden_tls_proto(name, attrs...) \
+ hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_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
+#if IS_IN (libnsl)
# define libnsl_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libnsl_hidden_tls_proto(name, attrs...) \
+ hidden_tls_proto (name, ##attrs)
+# ifdef LINK_OBSOLETE_NSL
+ /* libnsl_hidden_nolink should only get used in libnsl code. */
+# define libnsl_hidden_nolink_def(name, version) libnsl_hidden_def (name)
+# else
+# define libnsl_hidden_nolink_def(name, version) hidden_nolink (name, libnsl, version)
+# endif
# 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_tls_def(name) hidden_tls_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_tls_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_tls_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
+#if IS_IN (libnss_nisplus)
# define libnss_nisplus_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libnss_nisplus_hidden_tls_proto(name, attrs...) \
+ hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_def(name)
# define libnss_nisplus_hidden_data_weak(name)
# define libnss_nisplus_hidden_data_ver(local, name)
#endif
-#ifdef HAVE_BUILTIN_REDIRECTION
-# 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
-#else
-# define libc_hidden_builtin_proto(name, attrs...)
-# define libc_hidden_builtin_def(name)
-# define libc_hidden_builtin_weak(name)
-# define libc_hidden_builtin_ver(local, name)
-# ifdef __ASSEMBLER__
-# define HIDDEN_BUILTIN_JUMPTARGET(name) JUMPTARGET(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
+#if IS_IN (libutil)
# define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs)
+# define libutil_hidden_tls_proto(name, attrs...) \
+ hidden_tls_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_tls_def(name) hidden_tls_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_tls_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_tls_def(name)
# define libutil_hidden_data_weak(name)
# define libutil_hidden_data_ver(local, name)
#endif
# define compat_data_section .section ".data.compat", "aw";
#endif
+/* Helper / base macros for indirect function symbols. */
+#define __ifunc_resolver(type_name, name, expr, arg, init, classifier) \
+ classifier inhibit_stack_protector \
+ __typeof (type_name) *name##_ifunc (arg) \
+ { \
+ init (); \
+ __typeof (type_name) *res = expr; \
+ return res; \
+ }
+
+#ifdef HAVE_GCC_IFUNC
+# define __ifunc(type_name, name, expr, arg, init) \
+ extern __typeof (type_name) name __attribute__ \
+ ((ifunc (#name "_ifunc"))); \
+ __ifunc_resolver (type_name, name, expr, arg, init, static)
+
+# define __ifunc_hidden(type_name, name, expr, arg, init) \
+ __ifunc (type_name, name, expr, arg, init)
+#else
+/* Gcc does not support __attribute__ ((ifunc (...))). Use the old behaviour
+ as fallback. But keep in mind that the debug information for the ifunc
+ resolver functions is not correct. It contains the ifunc'ed function as
+ DW_AT_linkage_name. E.g. lldb uses this field and an inferior function
+ call of the ifunc'ed function will fail due to "no matching function for
+ call to ..." because the ifunc'ed function and the resolver function have
+ different signatures. (Gcc support is disabled at least on a ppc64le
+ Ubuntu 14.04 system.) */
+
+# define __ifunc(type_name, name, expr, arg, init) \
+ extern __typeof (type_name) name; \
+ __typeof (type_name) *name##_ifunc (arg) __asm__ (#name); \
+ __ifunc_resolver (type_name, name, expr, arg, init,) \
+ __asm__ (".type " #name ", %gnu_indirect_function");
+
+# define __ifunc_hidden(type_name, name, expr, arg, init) \
+ extern __typeof (type_name) __libc_##name; \
+ __ifunc (type_name, __libc_##name, expr, arg, init) \
+ strong_alias (__libc_##name, name);
+#endif /* !HAVE_GCC_IFUNC */
+
+/* The following macros are used for indirect function symbols in libc.so.
+ First of all, you need to have the function prototyped somewhere,
+ say in foo.h:
+
+ int foo (int __bar);
+
+ If you have an implementation for foo which e.g. uses a special hardware
+ feature which isn't available on all machines where this libc.so will be
+ used but decideable if available at runtime e.g. via hwcaps, you can provide
+ two or multiple implementations of foo:
+
+ int __foo_default (int __bar)
+ {
+ return __bar;
+ }
+
+ int __foo_special (int __bar)
+ {
+ return __bar;
+ }
+
+ If your function foo has no libc_hidden_proto (foo) defined for PLT
+ bypassing, you can use:
+
+ #define INIT_ARCH() unsigned long int hwcap = __GLRO(dl_hwcap);
+
+ libc_ifunc (foo, (hwcap & HWCAP_SPECIAL) ? __foo_special : __foo_default);
+
+ This will define a resolver function for foo which returns __foo_special or
+ __foo_default depending on your specified expression. Please note that you
+ have to define a macro function INIT_ARCH before using libc_ifunc macro as
+ it is called by the resolver function before evaluating the specified
+ expression. In this example it is used to prepare the hwcap variable.
+ The resolver function is assigned to an ifunc'ed symbol foo. Calls to foo
+ from inside or outside of libc.so will be indirected by a PLT call.
+
+ If your function foo has a libc_hidden_proto (foo) defined for PLT bypassing
+ and calls to foo within libc.so should always go to one specific
+ implementation of foo e.g. __foo_default then you have to add:
+
+ __hidden_ver1 (__foo_default, __GI_foo, __foo_default);
+
+ or a tweaked definition of libc_hidden_def macro after the __foo_default
+ function definition. Calls to foo within libc.so will always go directly to
+ __foo_default. Calls to foo from outside libc.so will be indirected by a
+ PLT call to ifunc'ed symbol foo which you have to define in a separate
+ compile unit:
+
+ #define foo __redirect_foo
+ #include <foo.h>
+ #undef foo
+
+ extern __typeof (__redirect_foo) __foo_default attribute_hidden;
+ extern __typeof (__redirect_foo) __foo_special attribute_hidden;
+
+ libc_ifunc_redirected (__redirect_foo, foo,
+ (hwcap & HWCAP_SPECIAL)
+ ? __foo_special
+ : __foo_default);
+
+ This will define the ifunc'ed symbol foo like above. The redirection of foo
+ in header file is needed to omit an additional defintion of __GI_foo which
+ would end in a linker error while linking libc.so. You have to specify
+ __redirect_foo as first parameter which is used within libc_ifunc_redirected
+ macro in conjunction with typeof to define the ifunc'ed symbol foo.
+
+ If your function foo has a libc_hidden_proto (foo) defined and calls to foo
+ within or from outside libc.so should go via ifunc'ed symbol, then you have
+ to use:
+
+ libc_ifunc_hidden (foo, foo,
+ (hwcap & HWCAP_SPECIAL)
+ ? __foo_special
+ : __foo_default);
+ libc_hidden_def (foo)
+
+ The first parameter foo of libc_ifunc_hidden macro is used in the same way
+ as for libc_ifunc_redirected macro. */
+
+#define libc_ifunc(name, expr) __ifunc (name, name, expr, void, INIT_ARCH)
+
+#define libc_ifunc_redirected(redirected_name, name, expr) \
+ __ifunc (redirected_name, name, expr, void, INIT_ARCH)
+
+#define libc_ifunc_hidden(redirected_name, name, expr) \
+ __ifunc_hidden (redirected_name, name, expr, void, INIT_ARCH)
+
+/* The body of the function is supposed to use __get_cpu_features
+ which will, if necessary, initialize the data first. */
+#define libm_ifunc_init()
+#define libm_ifunc(name, expr) \
+ __ifunc (name, name, expr, void, libm_ifunc_init)
+
+/* Add the compiler optimization to inhibit loop transformation to library
+ calls. This is used to avoid recursive calls in memset and memmove
+ default implementations. */
+#ifdef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
+# define inhibit_loop_to_libcall \
+ __attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
+#else
+# define inhibit_loop_to_libcall
+#endif
+\f
+/* These macros facilitate sharing source files with gnulib.
+
+ They are here instead of sys/cdefs.h because they should not be
+ used in public header files.
+
+ Their definitions should be kept consistent with the definitions in
+ gnulib-common.m4, but it is not necessary to cater to old non-GCC
+ compilers, since they will only be used while building glibc itself.
+ (Note that _GNUC_PREREQ cannot be used in this file.) */
+
+/* Define as a marker that can be attached to declarations that might not
+ be used. This helps to reduce warnings, such as from
+ GCC -Wunused-parameter. */
+#if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
+# define _GL_UNUSED __attribute__ ((__unused__))
+#else
+# define _GL_UNUSED
+#endif
+
+/* gcc supports the "unused" attribute on possibly unused labels, and
+ g++ has since version 4.5. Note to support C++ as well as C,
+ _GL_UNUSED_LABEL should be used with a trailing ; */
+#if !defined __cplusplus || __GNUC__ > 4 \
+ || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+# define _GL_UNUSED_LABEL _GL_UNUSED
+#else
+# define _GL_UNUSED_LABEL
+#endif
+
+/* The __pure__ attribute was added in gcc 2.96. */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE /* empty */
+#endif
+
+/* The __const__ attribute was added in gcc 2.95. */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
+# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
+#else
+# define _GL_ATTRIBUTE_CONST /* empty */
+#endif
+
+#endif /* !_ISOMAC */
#endif /* libc-symbols.h */
projects / thirdparty / glibc.git / blobdiff