Is there a way to suppress warnings in Xcode?
For example I am calling an undocumented method and since the method is not in the header I get a warning on compile. I know I can add it to my header to stop the warning, but I am wondering if there is a way other than adding it to the header (so I can keep the headers clean and standard) to suppress the warning? A pragma or something?
To disable warnings on a per-file basis, using Xcode 3 and llvm-gcc-4.2 you can use:
#pragma GCC diagnostic ignored "-Wwarning-flag"
Where warning name is some gcc warning flag.
This overrides any warning flags on the command line. It doesn't work with all warnings though. Add -fdiagnostics-show-option to your CFLAGS and you can see which flag you can use to disable that warning.
With Objective-C, a number of serious errors only appear as warnings. Not only do I never disable warnings, I normally turn on "Treat warnings as errors" (-Werror).
Every type of warning in your code can be avoided by doing things correctly (normally by casting objects to the correct type) or by declaring prototypes when you need them.
Suppressing that particular warning is not safe. The compiler needs to know the types of the arguments and returns to a method to generate correct code.
For example, if you're calling a method like this
[foo doSomethingWithFloat:1.0];
that takes a float, and there is no prototype visible, then the compiler will guess that the method takes a double, not a float. This can cause crashes and incorrectly interpreted values. In the example above, on a little endian machine like the intel machines, the receiver method would see 0 passed, not 1.
You can read why in the i386 ABI docs, or you can just fix your warnings. :-)