diff options
Diffstat (limited to 'm4/ax_ptrdiff_aliases_int.m4')
| -rw-r--r-- | m4/ax_ptrdiff_aliases_int.m4 | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/m4/ax_ptrdiff_aliases_int.m4 b/m4/ax_ptrdiff_aliases_int.m4 new file mode 100644 index 0000000..32e1712 --- /dev/null +++ b/m4/ax_ptrdiff_aliases_int.m4 @@ -0,0 +1,18 @@ + +AC_DEFUN([AX_PTRDIFF_ALIASES_INT], [ + AC_CACHE_CHECK([whether ptrdiff_t* aliases int*], [ax_cv_ptrdiff_aliases_int], [ + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ + @%:@include <stddef.h> + @%:@include <assert.h> + ]], [[ + ptrdiff_t x = 23; + _Static_assert(_Generic(&x, int* : 1, default : 0), + "ptrdiff_t* does not alias int*"); + ]])], + [ax_cv_ptrdiff_aliases_int=yes], + [ax_cv_ptrdiff_aliases_int=no]) + ]) + AS_IF([test "x$ax_cv_ptrdiff_aliases_int" = "xyes"], [ + AC_DEFINE([PTRDIFF_ALIASES_INT], [1], [Whether ptrdiff_t* aliases int*]) + ]) +])dnl |