/* Copyright (C) 1992,93,94,95,96,97,98,99,2000,2001 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #ifndef _SYS_CDEFS_H #define _SYS_CDEFS_H 1 /* We are almost always included from features.h. */ #ifndef _FEATURES_H # include <features.h> #endif /* The GNU libc does not support any K&R compilers or the traditional mode of ISO C compilers anymore. Check for some of the combinations not anymore supported. */ #if defined __GNUC__ && !defined __STDC__ # error "You need a ISO C conforming compiler to use the glibc headers" #endif /* Some user header file might have defined this before. */ #undef __P #undef __PMT #ifdef __GNUC__ /* GCC can always grok prototypes. For C++ programs we add throw() to help it optimize the function calls. But this works only with gcc 2.8.x and egcs. */ # if defined __cplusplus && __GNUC_PREREQ (2,8) # define __THROW throw () # else # define __THROW # endif # define __P(args) args __THROW /* This macro will be used for functions which might take C++ callback functions. */ # define __PMT(args) args #else /* Not GCC. */ # define __inline /* No inline functions. */ # define __THROW # define __P(args) args # define __PMT(args) args # define __const const # define __signed signed # define __volatile volatile #endif /* GCC. */ /* For these things, GCC behaves the ANSI way normally, and the non-ANSI way under -traditional. */ #define __CONCAT(x,y) x ## y #define __STRING(x) #x /* This is not a typedef so `const __ptr_t' does the right thing. */ #define __ptr_t void * #define __long_double_t long double /* C++ needs to know that types and declarations are C, not C++. */ #ifdef __cplusplus # define __BEGIN_DECLS extern "C" { # define __END_DECLS } #else # define __BEGIN_DECLS # define __END_DECLS #endif /* Support for bounded pointers. */ #ifndef __BOUNDED_POINTERS__ # define __bounded /* nothing */ # define __unbounded /* nothing */ # define __ptrvalue /* nothing */ #endif /* Support for flexible arrays. */ #if __GNUC_PREREQ (2,97) /* GCC 2.97 supports C99 flexible array members. */ # define __flexarr [] #else # ifdef __GNUC__ # define __flexarr [0] # else # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L # define __flexarr [] # else /* Some other non-C99 compiler. Approximate with [1]. */ # define __flexarr [1] # endif # endif #endif /* __asm__ ("xyz") is used throughout the headers to rename functions at the assembly language level. This is wrapped by the __REDIRECT macro, in order to support compilers that can do this some other way. When compilers don't support asm-names at all, we have to do preprocessor tricks instead (which don't have exactly the right semantics, but it's the best we can do). Example: int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */ #if defined __GNUC__ && __GNUC__ >= 2 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias)) # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname) # define __ASMNAME2(prefix, cname) __STRING (prefix) cname /* #elif __SOME_OTHER_COMPILER__ # define __REDIRECT(name, proto, alias) name proto; \ _Pragma("let " #name " = " #alias) */ #endif /* GCC has various useful declarations that can be made with the `__attribute__' syntax. All of the ways we use this do fine if they are omitted for compilers that don't understand it. */ #if !defined __GNUC__ || __GNUC__ < 2 # define __attribute__(xyz) /* Ignore */ #endif /* At some point during the gcc 2.96 development the `malloc' attribute for functions was introduced. We don't want to use it unconditionally (although this would be possible) since it generates warnings. */ #if __GNUC_PREREQ (2,96) # define __attribute_malloc__ __attribute__ ((__malloc__)) #else # define __attribute_malloc__ /* Ignore */ #endif /* At some point during the gcc 2.96 development the `pure' attribute for functions was introduced. We don't want to use it unconditionally (although this would be possible) since it generates warnings. */ #if __GNUC_PREREQ (2,96) # define __attribute_pure__ __attribute__ ((__pure__)) #else # define __attribute_pure__ /* Ignore */ #endif /* At some point during the gcc 2.8 development the `format_arg' attribute for functions was introduced. We don't want to use it unconditionally (although this would be possible) since it generates warnings. If several `format_arg' attributes are given for the same function, in gcc-3.0 and older, all but the last one are ignored. In newer gccs, all designated arguments are considered. */ #if __GNUC_PREREQ (2,8) # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x))) #else # define __attribute_format_arg__(x) /* Ignore */ #endif /* At some point during the gcc 2.97 development the `strfmon' format attribute for functions was introduced. We don't want to use it unconditionally (although this would be possible) since it generates warnings. */ #if __GNUC_PREREQ (2,97) # define __attribute_format_strfmon__(a,b) \ __attribute__ ((__format__ (__strfmon__, a, b))) #else # define __attribute_format_strfmon__(a,b) /* Ignore */ #endif /* It is possible to compile containing GCC extensions even if GCC is run in pedantic mode if the uses are carefully marked using the `__extension__' keyword. But this is not generally available before version 2.8. */ #if !__GNUC_PREREQ (2,8) # define __extension__ /* Ignore */ #endif /* __restrict is known in EGCS 1.2 and above. */ #if !__GNUC_PREREQ (2,92) # define __restrict /* Ignore */ #endif /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is array_name[restrict] GCC 3.1 supports this. */ #if __GNUC_PREREQ (3,1) && !defined __GNUG__ # define __restrict_arr __restrict #else # ifdef __GNUC__ # define __restrict_arr /* Not supported in old GCC. */ # else # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L # define __restrict_arr restrict # else /* Some other non-C99 compiler. */ # define __restrict_arr /* Not supported. */ # endif # endif #endif #endif /* sys/cdefs.h */