diff options
Diffstat (limited to 'jni/ruby/ccan/build_assert')
| -rw-r--r-- | jni/ruby/ccan/build_assert/build_assert.h | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/jni/ruby/ccan/build_assert/build_assert.h b/jni/ruby/ccan/build_assert/build_assert.h new file mode 100644 index 0000000..a04d1d4 --- /dev/null +++ b/jni/ruby/ccan/build_assert/build_assert.h @@ -0,0 +1,40 @@ +/* CC0 (Public domain) - see ccan/licenses/CC0 file for details */ +#ifndef CCAN_BUILD_ASSERT_H +#define CCAN_BUILD_ASSERT_H + +/** + * BUILD_ASSERT - assert a build-time dependency. + * @cond: the compile-time condition which must be true. + * + * Your compile will fail if the condition isn't true, or can't be evaluated + * by the compiler. This can only be used within a function. + * + * Example: + * #include <stddef.h> + * ... + * static char *foo_to_char(struct foo *foo) + * { + * // This code needs string to be at start of foo. + * BUILD_ASSERT(offsetof(struct foo, string) == 0); + * return (char *)foo; + * } + */ +#define BUILD_ASSERT(cond) \ + do { (void) sizeof(char [1 - 2*!(cond)]); } while(0) + +/** + * BUILD_ASSERT_OR_ZERO - assert a build-time dependency, as an expression. + * @cond: the compile-time condition which must be true. + * + * Your compile will fail if the condition isn't true, or can't be evaluated + * by the compiler. This can be used in an expression: its value is "0". + * + * Example: + * #define foo_to_char(foo) \ + * ((char *)(foo) \ + * + BUILD_ASSERT_OR_ZERO(offsetof(struct foo, string) == 0)) + */ +#define BUILD_ASSERT_OR_ZERO(cond) \ + (sizeof(char [1 - 2*!(cond)]) - 1) + +#endif /* CCAN_BUILD_ASSERT_H */ |