diff options
Diffstat (limited to 'include/libc-symbols.h')
| -rw-r--r-- | include/libc-symbols.h | 132 |
1 files changed, 44 insertions, 88 deletions
diff --git a/include/libc-symbols.h b/include/libc-symbols.h index dd573b32a8..8073fca575 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -76,121 +76,77 @@ # endif #endif +#ifndef __ASSEMBLER__ +/* GCC understands weak symbols and aliases; use its interface where + possible, instead of embedded assembly language. */ -/* Define ALIAS as a strong alias for ORIGINAL. */ -#ifdef HAVE_ASM_SET_DIRECTIVE -# define strong_alias_asm(original, alias) \ +/* Define ALIASNAME as a strong alias for NAME. */ +# 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__)) + +# 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) \ + extern __typeof (name) aliasname __attribute__ ((weak, alias (#name))); + +/* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined). */ +# ifdef HAVE_ASM_WEAKEXT_DIRECTIVE +# define weak_extern(symbol) asm (".weakext " __SYMBOL_PREFIX #symbol); +# else +# define weak_extern(symbol) asm (".weak " __SYMBOL_PREFIX #symbol); +# endif + +# else + +# define weak_alias(name, aliasname) strong_alias(name, aliasname) +# define weak_extern(symbol) /* Nothing. */ + +# endif + +#else /* __ASSEMBLER__ */ + +# ifdef HAVE_ASM_SET_DIRECTIVE +# define strong_alias(original, alias) \ ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias); \ .set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original) -# ifdef __ASSEMBLER__ -# define strong_alias(original, alias) strong_alias_asm (original, alias) # else -# define strong_alias(original, alias) \ - asm (__string_1 (ASM_GLOBAL_DIRECTIVE) " " __SYMBOL_PREFIX #alias "\n" \ - ".set " __SYMBOL_PREFIX #alias "," __SYMBOL_PREFIX #original); -# endif -#else -# define strong_alias_asm(original, alias) \ +# define strong_alias(original, alias) \ ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias); \ C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) -# ifdef __ASSEMBLER__ -# define strong_alias(original, alias) strong_alias_asm (original, alias) -# else -# define strong_alias(original, alias) \ - asm (__string_1 (ASM_GLOBAL_DIRECTIVE) " " __SYMBOL_PREFIX #alias "\n" \ - __SYMBOL_PREFIX #alias " = " __SYMBOL_PREFIX #original); # endif -#endif - -/* Helper macros used above. */ -#define __string_1(x) __string_0(x) -#define __string_0(x) #x - - -#ifdef HAVE_WEAK_SYMBOLS - -# ifdef __ASSEMBLER__ +# ifdef HAVE_WEAK_SYMBOLS # ifdef HAVE_ASM_WEAKEXT_DIRECTIVE - -/* Define ALIAS as a weak alias for ORIGINAL. - If weak aliases are not available, this defines a strong alias. */ # define weak_alias(original, alias) \ .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original) - -/* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined). */ # define weak_extern(symbol) \ .weakext C_SYMBOL_NAME (symbol) # else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ -/* Define ALIAS as a weak alias for ORIGINAL. - If weak aliases are not available, this defines a strong alias. */ # define weak_alias(original, alias) \ .weak C_SYMBOL_NAME (alias); \ C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original) - -/* Declare SYMBOL as weak undefined symbol (resolved to 0 if not defined). */ # define weak_extern(symbol) \ .weak C_SYMBOL_NAME (symbol) # endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ -# else /* ! __ASSEMBLER__ */ - -# ifdef HAVE_ASM_WEAKEXT_DIRECTIVE -# define weak_extern_asm(symbol) asm (".weakext " __SYMBOL_PREFIX #symbol); -# define weak_alias_asm(original, alias) \ - asm (".weakext " __SYMBOL_PREFIX #alias ", " __SYMBOL_PREFIX #original); -# else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ -# define weak_extern_asm(symbol) asm (".weak " __SYMBOL_PREFIX #symbol); -# define weak_alias_asm(original, alias) \ - asm (".weak " __SYMBOL_PREFIX #alias "\n" \ - __SYMBOL_PREFIX #alias " = " __SYMBOL_PREFIX #original); -# endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */ +# else /* ! HAVE_WEAK_SYMBOLS */ -# define weak_alias(o, a) weak_alias_asm (o, a) -# define weak_extern(symbol) weak_extern_asm (symbol) +# define weak_alias(original, alias) strong_alias(original, alias) +# define weak_extern(symbol) /* Nothing */ +# endif /* ! HAVE_WEAK_SYMBOLS */ -# endif /* ! __ASSEMBLER__ */ -#else -# define weak_alias(original, alias) strong_alias(original, alias) -# define weak_extern(symbol) /* Do nothing; the ref will be strong. */ -#endif - - -#if (!defined __ASSEMBLER__ && \ - (__GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7))) -/* GCC 2.7 and later has special syntax for weak symbols and aliases. - Using that is better when possible, because the compiler and assembler - are better clued in to what we are doing. */ -# undef strong_alias -# define strong_alias(name, aliasname) \ - extern __typeof (name) aliasname __attribute__ ((alias (#name))); - -# ifdef HAVE_WEAK_SYMBOLS -# undef weak_alias -# define weak_alias(name, aliasname) \ - extern __typeof (name) aliasname __attribute__ ((weak, 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__)) - -# endif /* HAVE_WEAK_SYMBOLS. */ -#endif /* Not __ASSEMBLER__, and GCC 2.7 or later. */ - - -#ifndef weak_function -/* If we do not have the __attribute__ ((weak)) syntax, there is no way we - can define functions as weak symbols. The compiler will emit a `.globl' - directive for the function symbol, and a `.weak' directive in addition - will produce an error from the assembler. */ -# define weak_function /* empty */ -# define weak_const_function /* empty */ -#endif +#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 |