Strange XCode debugger behavior with UITableView datasource

Question

Hey guys. I've got a perplexing issue. In my subclassed UITableViewController my datasource methods lose their tableview reference depending on lines of code I put inside the method. For example, in this code block:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.
    return 3;
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.
    return 5;
}


// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    id i = tableView;
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    // Configure the cell...

    return cell;
}

the "id i = tableView;" causes the tableview to become nil (0x0) -- and it causes it to be nil before I ever start stepping into the method.

If I insert an assignment statement above the "id i = tableview;" statement:

CGFloat x = 5.0;
id i = tableView;

then tableview retains its pointer (i.e. is not nil) if I place the breakpoint after the "id i = tableView;" line. In other words, the breakpoint must be set after the "id i = tableView"; assignment in order for tableView to retain its pointer.

If the breakpoint is set before the assignment is made and I just hang at that breakpoint for a bit then after a couple of seconds the console logs this error message:

Assertion failed: (cls), function getName, file /SourceCache/objc4_Sim/objc4-427.5/runtime/objc-runtime-new.mm, line 3990.

Although the code works when I don't step through the method, I need my debugger to work! It makes programming kind of challenging when your debugging tools become your enemy.

Anyone know what the cause and solution are? Thanks.

Answer 1

I have exactly the same issue and I don't know what is happening too :(