EXC_BAD_ACCESS error thrown in xcode

Question

My application crashes at various points while running, and result with the following error, in the same point in the code. My research indicates that this is a memory issue, but I am not sure why. I am not an app developer (rather a web developer), who has a decent understanding of Objective-C. I did not build this application either (Long Story).

#import <UIKit/UIKit.h>

int main(int argc, char *argv[])
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    int retVal = UIApplicationMain(argc, argv, nil, nil);        //Crashes with EXC_BAD_ACCESS
    [pool release];
    return retVal;
}

I know it is probably tough without knowing the rest of the application, but can anyone point me in the right direction as to what could cause this, or how I may begin to debug it?

NOTE: The application was not throwing this error until I fixed some memory leak issues. Not sure if that helps.

Check your release calls. The problem is in them! Try to comment all and one by one uncomment them or use NSZombie class — Nekto, Aug 28 '11 at 17:46

score 3 · Accepted Answer · answered Aug 28 '11 at 17:45

3

The right direction is to use Instruments (comes with Xcode in the /Developer/Applications folder). If it's an EXC_BAD_ACCESS, your best bet is the Zombies instrument.

answered Aug 28 '11 at 17:45

Joshua Nozzi

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score 0 · Answer 2 · edited May 23 '17 at 11:55

Depending on whether you are using Xcode 4 or an earlier version, SO answer found at How to enable NSZombie in Xcode? might be helpful; in your question the error is reported at the topmost level, hence as you thought that's not particularly useful to tell about the error source.

A two cents feedback I can provide you with is that I experienced something similar first time I tried the Static Analyzer; following its reports I tried to fix potential leaks, actually causing a resource to be freed ahead of time. The tool is helpful, but it needs more time to be mastered than it may seem at the beginning. It looks like as a push button, but it is not exactly, as the try-to-fix solution might look proper also when it is not (you just went beyond its abilities to analyze, making a more "subtle" mistake ;) ).

You don't have to enable NSZombie. Just run the app in Instruments with the Zombies instrument and you're all set with a very comprehensive GUI wrapper around DTrace. — Joshua Nozzi, Aug 28 '11 at 20:07

EXC_BAD_ACCESS error thrown in xcode

2 Answers2