newlib/libc/include/_ansi.h

   1 /* Provide support for both ANSI and non-ANSI environments.  */
   2
   3 /* To get a strict ANSI C environment, define macro __STRICT_ANSI__.  This will
   4    "comment out" the non-ANSI parts of the ANSI header files (non-ANSI header
   5    files aren't affected).  */
   6
   7 #ifndef _ANSIDECL_H_
   8 #define _ANSIDECL_H_
   9
  10 #include <newlib.h>
  11 #include <sys/config.h>
  12
  13 /*  ISO C++.  */
  14
  15 #ifdef __cplusplus
  16 #if !(defined(_BEGIN_STD_C) && defined(_END_STD_C))
  17 #ifdef _HAVE_STD_CXX
  18 #define _BEGIN_STD_C namespace std { extern "C" {
  19 #define _END_STD_C  } }
  20 #else
  21 #define _BEGIN_STD_C extern "C" {
  22 #define _END_STD_C  }
  23 #endif
  24 #if __GNUC_PREREQ (3, 3)
  25 #define _NOTHROW __attribute__ ((__nothrow__))
  26 #else
  27 #define _NOTHROW throw()
  28 #endif
  29 #endif
  30 #else
  31 #define _BEGIN_STD_C
  32 #define _END_STD_C
  33 #define _NOTHROW
  34 #endif
  35
  36 #ifndef _LONG_DOUBLE
  37 #define _LONG_DOUBLE long double
  38 #endif
  39
  40 /* Support gcc's __attribute__ facility.  */
  41
  42 #ifdef __GNUC__
  43 #define _ATTRIBUTE(attrs) __attribute__ (attrs)
  44 #else
  45 #define _ATTRIBUTE(attrs)
  46 #endif
  47
  48 /*  The traditional meaning of 'extern inline' for GCC is not
  49   to emit the function body unless the address is explicitly
  50   taken.  However this behaviour is changing to match the C99
  51   standard, which uses 'extern inline' to indicate that the
  52   function body *must* be emitted.  Likewise, a function declared
  53   without either 'extern' or 'static' defaults to extern linkage
  54   (C99 6.2.2p5), and the compiler may choose whether to use the
  55   inline version or call the extern linkage version (6.7.4p6).
  56   If we are using GCC, but do not have the new behaviour, we need
  57   to use extern inline; if we are using a new GCC with the
  58   C99-compatible behaviour, or a non-GCC compiler (which we will
  59   have to hope is C99, since there is no other way to achieve the
  60   effect of omitting the function if it isn't referenced) we use
  61   'static inline', which c99 defines to mean more-or-less the same
  62   as the Gnu C 'extern inline'.  */
  63 #if defined(__GNUC__) && !defined(__GNUC_STDC_INLINE__)
  64 /* We're using GCC, but without the new C99-compatible behaviour.  */
  65 #define _ELIDABLE_INLINE extern __inline__ _ATTRIBUTE ((__always_inline__))
  66 #else
  67 /* We're using GCC in C99 mode, or an unknown compiler which
  68   we just have to hope obeys the C99 semantics of inline.  */
  69 #define _ELIDABLE_INLINE static __inline__
  70 #endif
  71
  72 #if __GNUC_PREREQ (3, 1)
  73 #define _NOINLINE               __attribute__ ((__noinline__))
  74 #define _NOINLINE_STATIC        _NOINLINE static
  75 #else
  76 /* On non-GNU compilers and GCC prior to version 3.1 the compiler can't be
  77    trusted not to inline if it is static. */
  78 #define _NOINLINE
  79 #define _NOINLINE_STATIC
  80 #endif
  81
  82 #endif /* _ANSIDECL_H_ */