| #include <stdio.h> |
| #include <string.h> |
| #include "config.h" |
| |
| /** |
| * build_assert - routines for build-time assertions |
| * |
| * This code provides routines which will cause compilation to fail should some |
| * assertion be untrue: such failures are preferable to run-time assertions, |
| * but much more limited since they can only depends on compile-time constants. |
| * |
| * These assertions are most useful when two parts of the code must be kept in |
| * sync: it is better to avoid such cases if possible, but seconds best is to |
| * detect invalid changes at build time. |
| * |
| * For example, a tricky piece of code might rely on a certain element being at |
| * the start of the structure. To ensure that future changes don't break it, |
| * you would catch such changes in your code like so: |
| * |
| * Example: |
| * #include <stddef.h> |
| * #include <ccan/build_assert/build_assert.h> |
| * |
| * struct foo { |
| * char string[5]; |
| * int x; |
| * }; |
| * |
| * static char *foo_string(struct foo *foo) |
| * { |
| * // This trick requires that the string be first in the structure |
| * BUILD_ASSERT(offsetof(struct foo, string) == 0); |
| * return (char *)foo; |
| * } |
| * |
| * License: CC0 (Public domain) |
| * Author: Rusty Russell <rusty@rustcorp.com.au> |
| */ |
| int main(int argc, char *argv[]) |
| { |
| if (argc != 2) |
| return 1; |
| |
| if (strcmp(argv[1], "depends") == 0) |
| /* Nothing. */ |
| return 0; |
| |
| return 1; |
| } |