I'm using Apple TapDetectingImageView class from Autoscroll example.
Static analizer shows the following warning:
Classes/TapDetectingImageView.m:68:30:{68:17-68:29}: warning:
The left operand of '==' is a garbage value
if (tapCounts[0] == 1 && tapCounts[1] == 1) {
~~~~~~~~~~~~ ^
for the attached code below. Garbage value occurs when a variable is read without having been initialized first. But it seems tapCounts is initialized already.
Can I ignore it if the app is running fine or should I modify anything?
BOOL allTouchesEnded = ([touches count] == [[event touchesForView:self] count]);
// first check for plain single/double tap, which is only possible if we haven't seen multiple touches
if (!multipleTouches) {
UITouch *touch = [touches anyObject];
tapLocation = [touch locationInView:self];
if ([touch tapCount] == 1) {
[self performSelector:@selector(handleSingleTap) withObject:nil afterDelay:DOUBLE_TAP_DELAY];
} else if([touch tapCount] == 2) {
[self handleDoubleTap];
}
}
// check for 2-finger tap if we've seen multiple touches and haven't yet ruled out that possibility
else if (multipleTouches && twoFingerTapIsPossible) {
// case 1: this is the end of both touches at once
if ([touches count] == 2 && allTouchesEnded) {
int i = 0;
int tapCounts[2]; CGPoint tapLocations[2];
for (UITouch *touch in touches) {
tapCounts[i] = [touch tapCount];
tapLocations[i] = [touch locationInView:self];
i++;
}
if (tapCounts[0] == 1 && tapCounts[1] == 1) { // it's a two-finger tap if they're both single taps
tapLo开发者_JS百科cation = midpointBetweenPoints(tapLocations[0], tapLocations[1]);
[self handleTwoFingerTap];
}
}
This occurs when a variable is created but NOT initialized to a value. In the code above you do this:
int tapCounts[2];
...
But then don't initialize the array contents to anything before attempting to evaluate it in the if statement a few lines down:
if( tapCounts[0] == 1 && tapCounts[1] == 1 ) {
....
}
The compiler is warning you that the contents of tapCounts[0] is not initialized and is garbage.
It's due to tapCounts array is initialized with garbage values for index 0 and 1.
Please change the line:
int tapCounts[2]; CGPoint tapLocations[2];
with
int tapCounts[2] = {0,0}; CGPoint tapLocations[2] = {0,0};
This will remove the initialize warning while analyzing build
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