Display runtime error message on specific line in Xcode

Question

I would like to display custom error message during runtime in Xcode in C/C++ code. This could be used for example for custom assert() function.

I would like to display message inline, like SenTestingKit does:

Right now the only thing I can do is use __builtin_trap to stop at the correct line. But no custom error message is displayed.

Answer 1

I'm not familiar with xcode but here's how it's done almost everywhere else. Your custom assert will look like this:

#define MY_ASSERT(a1, a2, desc, ...) {\
     PrintAssertMessage(...);         \  
     DebugBreak();                    \
}

In windows there's already a DebugBreak function in win32 API. In Linux and most other systems that run IA32/X64 you can simply call int 3 which is the breakpoint trap.

asm  ("int 3");

I read that in xcode it's:

__asm {int 3}

or

__asm__("int $3")

or

__asm__("trap")

In any case this should be surrounded by a macro that disables the assert in debug builds as well macro that defines how to cause a break point.