silence -Wparentheses-equality error

Question

Im building som software using boost 1.48 on osx 10.8 with gcc version 4.2.1 and i have started getting -Wparentheses-equality warnings for some of the boost source.

  equality comparison with extraneous parentheses
  [-Werror,-Wparentheses-equality]
        else if((state->type == syntax_element_long_set_rep)) 

I would change the code but i dont want to tinker with the library, how would i silence the warning and make the compiler continue?

Answer 1

From the GCC manual:

Most of these have both positive and negative forms; the negative form of -ffoo would be -fno-foo.

Try -Wno-parentheses-equality.

Answer 2

As an alternative to simply disabling the warning you can also specify certain paths to count as 'system' paths. Warnings are suppressed for system headers, so you can declare that a particular library's headers are 'system' headers and that you don't care about warnings in them.

clang's argument for this is --system-header-prefix=<prefix>

So for example you might say "--system-header-prefix=boost/"

http://clang.llvm.org/docs/UsersManual.html#controlling-diagnostics-in-system-headers

And judging by the error message you are actually using clang and not gcc.