When NDEBUG is not set, standard implementations of "assert" do something like this:
#define assert(X) ((void) ((X) || __assert_fail (#X, __FILE__, __LINE__, __func__)) Sometimes I'd rather have something smaller and faster in production code, something like this: #if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 3) #define __builtin_trap() abort () #endif #define assert(X) ((void) ((X) || (__builtin_trap (), 0))) as this is good enough if you have a debugger, and it prevents code bloat. For example, with GCC 4.6.0 on x86-64, this would typically save about 50 bytes of code space per 'assert', or more if the assertion is a long expression. Of course I could do this with a new macro (assert_trap, say), but that'd be an intrusive change into the source code. I'm thinking of adding a new module, "assert-trap" say, that modifies assert.h so that "assert" has the above behavior. I know the resulting assert.h wouldn't conform to the C standard, because the C standard requires a runtime diagnostic with the file name, but that's OK. Similarly, I'm thinking of adding a new module "abort-trap" that does the same for abort (). This wouldn't be as big a savings -- only 3 bytes of instruction per abort call, on an x86 -- but it should squeeze more instructions into the cache and thus help performance in some cases. Comments?
