[cfe-dev] Clang + ccache == different warnings?

[Joerg Sonnenberger]

On Fri, Jun 01, 2012 at 12:08:42PM -0700, Larry Gritz wrote:
> Obviously this just calls ccache with the clang path and arguments.
> The surprising thing is that when I invoke clang this way, several
> classes of warnings are flagged that were not noticed when I ran
> /opt/local/bin/clang.

You are hitting the same behavior as building with -save-temps.
Basically, a number of warnings check if they are the result of a macro
expansion. If yes, they get suppressed.

Joerg