On Fri, 31 Mar 2023 at 22:55, Jonny Grant wrote: > > Hello > > May I check, does this attribute error output the error message usually? > My example links fine without any warnings or errors. > > Maybe I am misunderstanding it. I am sharing a simple program below and godbolt trunk example. > I only get to see the error message if I don't implement the function and get a link failure. Are you sure about that? If you remove the definition, you should get the error: https://godbolt.org/z/z1hjn6Yan > > https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#Common-Function-Attributes > > error ("message") > warning ("message") > > If the error or warning attribute is used on a function declaration and a call to such a function is not eliminated through dead code elimination or other optimizations, an error or warning (respectively) that includes message is diagnosed. > > > > https://godbolt.org/z/n849GPTjj > > > void compile_abort() __attribute__((error("compile abort"))); > > void compile_abort() > { > __builtin_abort(); > } > > int main() > { > compile_abort(); > }
