Menu
I understand exactly why unused variable warnings occur. I don't want to suppress them in general, because they are incredibly useful in most cases. However, consider the following (contrived) code.
NSError *error = nil;
BOOL saved = [moc save:&error];
NSAssert1(saved, @"Dude!!1! %@!!!", error);
Xcode reports that saved is an unused variable, when of course it isn't. I suspect this is because NSAssert1 is a macro. The NS_BLOCK_ASSERTIONS macro is not defined, so Objective C assertions are definitely enabled.
While it doesn't hurt anything, I find it untidy and annoying, and I want to suppress it, but I'm not sure how to do so. Assigning the variable to itself gets rid of the compiler warning, but I'd rather do it the "right" way if such a thing exists.
392
By default, the compiler does not warn about unused variables. Use -Wunused-variable to enable this warning specifically, or use an encompassing -W value such as -Weverything . The __attribute__((unused)) attribute can be used to warn about most unused variables, but suppress warnings for a specific set of variables.
Select your project and select your target and show Build Phases . Search the name of the file in which you want to hide, and you should see it listed in the Compile Sources phase. Double-click in the Compiler Flags column for that file and enter -w to turn off all warnings for that file.
I want "Jump to Next Error" (a way to skip the warnings), but it doesn't seem to exist. If you want to disable all warnings, you can pass the -suppress-warnings flag (or turn on "Suppress Warnings" under "Swift Compiler - Warning Policies" in Xcode build settings).
Reports the parameters that are considered unused in the following cases: The parameter is passed by value, and the value is not used anywhere or is overwritten immediately. The parameter is passed by reference, and the reference is not used anywhere or is overwritten immediately.
I'm unsure if it's still supported in the new LLVM compiler, but GCC has an "unused" attribute you can use to suppress that warning:
BOOL saved __attribute__((unused)) = [moc save:&error];
Alternatively (in case LLVM doesn't support the above), you could split the variable declaration into a separate line, guaranteeing that the variable would be "used" whether the macro expands or not:
BOOL saved = NO;
saved = [moc save:&error];
Using Xcode 4.3.2 and found out that this seems to work (less writing)
BOOL saved __unused;
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
