How can I make this GCC warning an error?

Question

I'm not sure what the correct warning is, but once you've found it, you can change its disposition with the following (using 'format' as the example):

#pragma GCC diagnostic error "-Wformat"

Or as strager points out:

gcc -Werror=format ...

I've checked the gcc source for this and this specific warning cannot be disabled via command line flags.

-Werror=specific-warning will turn the specified -Wspecific-warning into an error in GCC 4.3.x or newer. In 4.1.2, only -Werror-implicit-function-declaration works. Note the hyphen instead of equals sign -- it works for that specific case only and no others. This is one of the more serious common warnings and it's definitely handy to make it into an error.

Apart from that, older versions of GCC only seem to provide the -Werror sledgehammer of making every last warning an error.

It sounds like there are a bunch of other warnings that you don't want to be turned into errors (using the -Werror flag). In general, it's good practice to fix all warnings. Using -Werror forces this.

You can use the -Werror compiler flag to turn all or some warnings into errors.

You can use -fdiagnostics-show-option to see the -W option that applies to a particular warning.

Unfortunately, in this case there isn't any specific option that covers that warning.

It appears that there will be better support for this in GCC 4.5.