From: George Burgess IV <gbiv@xxxxxxxxxx> Subject: tools/build: tweak unused value workaround Clang has -Wself-assign enabled by default under -Wall, which always gets -Werror'ed on this file, causing sync-compare-and-swap to be disabled by default. The generally-accepted way to spell "this value is intentionally unused," is casting it to `void`. This is accepted by both GCC and Clang with -Wall enabled: https://godbolt.org/z/qqZ9r3 Link: http://lkml.kernel.org/r/20200414195638.156123-1-gbiv@xxxxxxxxxx Signed-off-by: George Burgess IV <gbiv@xxxxxxxxxx> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/build/feature/test-sync-compare-and-swap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/build/feature/test-sync-compare-and-swap.c~tools-build-tweak-unused-value-workaround +++ a/tools/build/feature/test-sync-compare-and-swap.c @@ -7,7 +7,7 @@ int main(int argc, char *argv[]) { uint64_t old, new = argc; - argv = argv; + (void)argv; do { old = __sync_val_compare_and_swap(&x, 0, 0); } while (!__sync_bool_compare_and_swap(&x, old, new)); _
