__builtin_debugtrap viability

[jimon]

It seems like all compilers GCC 4.x+, clang 3+?, MSVC 2015+ (except for ARM, where it's MSVC 2018+) do support __builtin_debugtrap and generate, what looks like, a viable asm.

I'm trying https://go.godbolt.org/ with:

#include <stdio.h>
int main()
{
	__builtin_debugtrap();
	printf("hello world\n");
	return 0;
}

And it seems to work in vast majority of cases.

Do you think it is a viable solution to use?

[scottt]

@jimon, I just played around with godbolt again and I'm pretty sure of the compiler it supports, __builtin_debugtrap only works on x86-64 clang.

If you see something like call __builtin_debugtrap, or bl __builtin_debugtrap in the output, where the compiler generates a call to an external function instead of the desired breakpoint instruction, you should interpret that as __builtin_debugtrap not working.

[jimon]

@scottt thanks! Yeah, I get now why this was looking to good to be true :)