diff options
| author | Luke T. Shumaker <lukeshu@lukeshu.com> | 2025-04-18 07:14:27 -0600 |
|---|---|---|
| committer | Luke T. Shumaker <lukeshu@lukeshu.com> | 2025-04-18 16:46:50 -0600 |
| commit | 957db32f46ca468043e1699817273a3e228c1ffb (patch) | |
| tree | d0ce176f48866cdd9825901ac0f105b5785da2c9 | |
| parent | 740bffed4da51c4d46a1295baabe3bd249cf9138 (diff) | |
libmisc: LM_ARRAY_LEN: Compiler-error if not array
| -rw-r--r-- | libmisc/include/libmisc/assert.h | 11 | ||||
| -rw-r--r-- | libmisc/include/libmisc/macro.h | 6 |
2 files changed, 11 insertions, 6 deletions
diff --git a/libmisc/include/libmisc/assert.h b/libmisc/include/libmisc/assert.h index 8cf0735..0563a58 100644 --- a/libmisc/include/libmisc/assert.h +++ b/libmisc/include/libmisc/assert.h @@ -1,6 +1,6 @@ /* libmisc/assert.h - More assertions * - * Copyright (C) 2024 Luke T. Shumaker <lukeshu@lukeshu.com> + * Copyright (C) 2024-2025 Luke T. Shumaker <lukeshu@lukeshu.com> * SPDX-License-Identifier: AGPL-3.0-or-later */ @@ -16,9 +16,10 @@ const char *msg); #endif -#define assert_msg(expr, msg) __assert_msg(expr, #expr, msg) /* libmisc */ -#define assert(expr) __assert_msg(expr, #expr, 0) /* C89, POSIX-2001 */ -#define assert_notreached(msg) do { __assert_msg(0, "notreached", msg); __builtin_unreachable(); } while (0) /* libmisc */ -#define static_assert _Static_assert /* C11 */ +#define assert_msg(expr, msg) __assert_msg(expr, #expr, msg) /* libmisc */ +#define assert(expr) __assert_msg(expr, #expr, 0) /* C89, POSIX-2001 */ +#define assert_notreached(msg) do { __assert_msg(0, "notreached", msg); __builtin_unreachable(); } while (0) /* libmisc */ +#define static_assert _Static_assert /* C11 */ +#define static_assert_as_expr(...) (sizeof(struct {static_assert(__VA_ARGS__);})) /* libmisc */ #endif /* _LIBMISC_ASSERT_H_ */ diff --git a/libmisc/include/libmisc/macro.h b/libmisc/include/libmisc/macro.h index 6cb15fb..a95ac82 100644 --- a/libmisc/include/libmisc/macro.h +++ b/libmisc/include/libmisc/macro.h @@ -7,6 +7,8 @@ #ifndef _LIBMISC_MACRO_H_ #define _LIBMISC_MACRO_H_ +#include <libmisc/assert.h> + /* for function definitions */ #define LM_UNUSED(argname) @@ -16,7 +18,9 @@ /* types */ -#define LM_ARRAY_LEN(ary) (sizeof(ary)/sizeof((ary)[0])) +/* If it's a pointer instead of an array, then typeof(&ptr[0]) == typeof(ptr) */ +#define _LM_IS_ARRAY(ary) (!__builtin_types_compatible_p(typeof(&(ary)[0]), typeof(ary))) +#define LM_ARRAY_LEN(ary) ( (sizeof(ary)/sizeof((ary)[0])) + static_assert_as_expr(_LM_IS_ARRAY(ary)) ) #define LM_CAST_FIELD_TO_STRUCT(STRUCT_TYP, FIELD_NAME, PTR_TO_FIELD) ({ \ /* The _fptr assignment is to get the compiler to do type checking. */ \ |