Is there an gcc/Xcode pragma to suppress warnings?

Question

Is there a #pragma to have gcc/Xcode suppress specific warnings, similar to Java's @SuppressWarning annotation?

I compile with -Wall as a rule, but there are some situations where I'd like to just ignore a specific warning (e.g. while writing some quick/dirty code just to help debug something).

I'm not looking for "fix the code" answers.

Answer 1

Here's a viable solution. Use #pragma GCC system_header to let GCC handle your code in a very special way, thus suppressing any non fatal #warning.

Remeber you're just fooling your preprocessor, not the real compiler. Suppressing warnings could be harmful most of times.

Answer 2

In gcc4.6 and later you can use pragma's to suppress specific warnings and do that suppression only to a specific block of code, i.e. :

#pragma GCC diagnostic 
push #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 
// Code that causes warning goes here
#pragma GCC diagnostic pop

The push/pop are used to preserve the diagnostic options that were in place before your code was processed.

This would be a much better approach than using "#pragma GCC system_header" to suppress all warnings. (Of course, in older gcc you may be "stuck" with the #pragma GCC system_header approach!)

Here's a nice reference on suppressing gcc warnings: http://www.dbp-consulting.com/tutorials/SuppressingGCCWarnings.html

This page also describes how to use -fdiagnostics-show-option to find out what option controls a particular warning.

Of course, as others mention, it's generally far preferable to fix the root cause of all warnings than to suppress them! However, sometimes that is not possible.