Hello Bruce, After reading through your email, I think it's best to fix things using the following patch. Essentially it does the following:
- It makes sure __alignof() is always present, by defining it as a macro
for GCC < 2.95.
- All the C1X macros can now be implemented using the ones we already
had (__dead2, etc). This means we don't need to repeat all the
compiler version specific checks.
- While there, add struct __hack to the _Static_assert, as it always
requires a semicolon.
Thanks for your feedback.
| Index: sys/sys/cdefs.h
| ===================================================================
| --- sys/sys/cdefs.h (revision 228504)
| +++ sys/sys/cdefs.h (working copy)
| @@ -230,27 +230,24 @@
| #elif defined(__STDC_VERSION__) && __STDC_VERSION__ > 201000L
| /* Do nothing. They are language keywords. */
| #else
| -/* Not supported. Implement them manually. */
| -#ifdef __GNUC__
| -#define _Alignas(e) __attribute__((__aligned__(e)))
| -#define _Alignof(e) __alignof__(e)
| -#define _Noreturn __attribute__((__noreturn__))
| +/* Not supported. Implement them using our versions. */
| +#define _Alignas(e) __aligned(e)
| +#define _Alignof(e) __alignof(e)
| +#define _Noreturn __dead2
| #define _Thread_local __thread
| -#else
| -#define _Alignas(e)
| -#define _Alignof(e) __offsetof(struct { char __a; e __b; },
__b)
| -#define _Noreturn
| -#define _Thread_local
| -#endif
| #ifdef __COUNTER__
| #define _Static_assert(e, s) __Static_assert(e, __COUNTER__)
| #define __Static_assert(e, c) ___Static_assert(e, c)
| #define ___Static_assert(e, c) typedef char __assert ## c[(e) ? 1 : -1]
| #else
| -#define _Static_assert(e, s)
| +#define _Static_assert(e, s) struct __hack
| #endif
| #endif
|
| +#if !__GNUC_PREREQ__(2, 95)
| +#define __alignof(x) __offsetof(struct { char __a; e __b; }, __b)
| +#endif
| +
| #if __GNUC_PREREQ__(2, 96)
| #define __malloc_like __attribute__((__malloc__))
| #define __pure __attribute__((__pure__))
--
Ed Schouten <e...@80386.nl>
WWW: http://80386.nl/
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