Passing GCC arguments up from source code

[Hamilton, Steve]

I'd like a way of passing compiler arguments up from specific source files.
For example, there are certain warning levels that I'd like to apply to
(almost) all of my files, and enforce with '-Werror'.  However, there are
some cases that I can't address.  For those cases, I'd like to turn off
specific warnings for that file only (e.g., using '#pragma ...').  How can I
do this?  Thanks.