Xcode equivalent of ' __asm int 3 / DebugBreak() / Halt?

Question

What\'s the instruction to cause a hard-break in Xcode? For example under Visual Studio I could do \'_asm int 3\' or \'DebugBreak()\'. Under some GCC implementations it\'s a

Answer 1

__builtin_trap();

Since Debugger() is depreciated now this should work instead.

https://developer.apple.com/library/mac/technotes/tn2124/_index.html#//apple_ref/doc/uid/DTS10003391-CH1-SECCONTROLLEDCRASH

Answer 2

I found the following in an Apple Forum:

Xcode doesn't come with any symbolic breaks built in - but they're quick to add. Go to the breakpoints window and add:

-[NSException raise]

Answer 3

For posterity: I have some code for generating halts at the correct stack frame in the debugger and (optionally) pausing the app so you can attach the debugger just-in-time. Works for simulator and device (and possibly desktop, if you should ever need it). Exhaustively detailed post at http://iphone.m20.nl/wp/2010/10/xcode-iphone-debugger-halt-assertions/

Answer 4

You can just insert a call to Debugger() — that will stop your app in the debugger (if it's being run under the debugger), or halt it with an exception if it's not.

Also, do not avoid assert() for "portability reasons" — portability is why it exists! It's part of Standard C, and you'll find it wherever you find a C compiler. What you really want to do is define a new assertion handler that does a debugger break instead of calling abort(); virtually all C compilers offer a mechanism by which you can do this.

Typically this is done by simply implementing a function or macro that follows this prototype:

void __assert(const char *expression, const char *file, int line);

It's called when an assertion expression fails. Usually it, not assert() itself, is what performs "the printf() followed by abort()" that is the default documented behavior. By customizing this function or macro, you can change its behavior.

Answer 5

kill(getpid(), SIGINT);

Works in the simulator and the device.

Answer 6

There is also the following function that is available as cross platform straight Halt() alternative:

#include <stdlib.h>

void abort(void);

We use it in our cross platform engine for the iPhone implementation in case of fatal asserts. Cross platform across Nintendo DS/Wii/XBOX 360/iOS etc...