Home | History | Annotate | Line # | Download | only in m4 
      1 # Check for stdbool.h that conforms to C99.
      2 
      3 dnl Copyright (C) 2002-2004 Free Software Foundation, Inc.
      4 dnl This file is free software; the Free Software Foundation
      5 dnl gives unlimited permission to copy and/or distribute it,
      6 dnl with or without modifications, as long as this notice is preserved.
      7 
      8 # Prepare for substituting <stdbool.h> if it is not supported.
      9 
     10 AC_DEFUN([AM_STDBOOL_H],
     11 [
     12   AC_REQUIRE([AC_HEADER_STDBOOL])
     13 
     14   # Define two additional variables used in the Makefile substitution.
     15 
     16   if test "$ac_cv_header_stdbool_h" = yes; then
     17     STDBOOL_H=''
     18   else
     19     STDBOOL_H='stdbool.h'
     20   fi
     21   AC_SUBST([STDBOOL_H])
     22 
     23   if test "$ac_cv_type__Bool" = yes; then
     24     HAVE__BOOL=1
     25   else
     26     HAVE__BOOL=0
     27   fi
     28   AC_SUBST([HAVE__BOOL])
     29 ])
     30 
     31 # This macro is only needed in autoconf <= 2.59.  Newer versions of autoconf
     32 # have this macro built-in.
     33 
     34 AC_DEFUN([AC_HEADER_STDBOOL],
     35   [AC_CACHE_CHECK([for stdbool.h that conforms to C99],
     36      [ac_cv_header_stdbool_h],
     37      [AC_TRY_COMPILE(
     38 	[
     39 	  #include <stdbool.h>
     40 	  #ifndef bool
     41 	   "error: bool is not defined"
     42 	  #endif
     43 	  #ifndef false
     44 	   "error: false is not defined"
     45 	  #endif
     46 	  #if false
     47 	   "error: false is not 0"
     48 	  #endif
     49 	  #ifndef true
     50 	   "error: true is not defined"
     51 	  #endif
     52 	  #if true != 1
     53 	   "error: true is not 1"
     54 	  #endif
     55 	  #ifndef __bool_true_false_are_defined
     56 	   "error: __bool_true_false_are_defined is not defined"
     57 	  #endif
     58 
     59 	  struct s { _Bool s: 1; _Bool t; } s;
     60 
     61 	  char a[true == 1 ? 1 : -1];
     62 	  char b[false == 0 ? 1 : -1];
     63 	  char c[__bool_true_false_are_defined == 1 ? 1 : -1];
     64 	  char d[(bool) -0.5 == true ? 1 : -1];
     65 	  bool e = &s;
     66 	  char f[(_Bool) -0.0 == false ? 1 : -1];
     67 	  char g[true];
     68 	  char h[sizeof (_Bool)];
     69 	  char i[sizeof s.t];
     70 	  enum { j = false, k = true, l = false * true, m = true * 256 };
     71 	  _Bool n[m];
     72 	  char o[sizeof n == m * sizeof n[0] ? 1 : -1];
     73 	],
     74 	[
     75 	  return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !j + !k + !l
     76 		  + !m + !n + !o);
     77 	],
     78 	[ac_cv_header_stdbool_h=yes],
     79 	[ac_cv_header_stdbool_h=no])])
     80    AC_CHECK_TYPES([_Bool])
     81    if test $ac_cv_header_stdbool_h = yes; then
     82      AC_DEFINE(HAVE_STDBOOL_H, 1, [Define to 1 if stdbool.h conforms to C99.])
     83    fi])
     84