How is this for a proposed patch?
Provide a fallback definition for _Static_assert for when the compiler doesn't provide it (it doesn't have to for pre-C11). Fixes https://rt.perl.org/Public/Bug/Display.html?id=134023 Index: cdefs.h =================================================================== RCS file: /cvsroot/src/sys/sys/cdefs.h,v retrieving revision 1.141 diff -u -r1.141 cdefs.h --- cdefs.h 21 Feb 2019 21:34:05 -0000 1.141 +++ cdefs.h 22 May 2019 18:39:41 -0000 @@ -158,6 +158,14 @@ #define __CTASSERT1(x, y, z) typedef char y ## z[/*CONSTCOND*/(x) ? 1 : -1] __unused /* + * Fallback definition to _Static_assert, part of C11, + * normally provided by the compiler. + */ +#if (__STDC_VERSION__ - 0 < 201101L) +#define _Static_assert(expr, message) __CTASSERT(expr) +#endif + +/* * The following macro is used to remove const cast-away warnings * from gcc -Wcast-qual; it should be used with caution because it * can hide valid errors; in particular most valid uses are in
