[llvm] r234343 - Enable W4 warnings by default for MSVC builds

[Aaron Ballman]

On Mon, Apr 13, 2015 at 2:16 PM, Zachary Turner <zturner at google.com> wrote:
> Hi Andy, this is causing a huge slew of warning spam.  Is this expected?
> CMake passes /W3 by default, so  every single translation unit I compile
> gives me the following warning:
>
> cl : Command line warning D9025 : overriding '/W3' with '/W4'
>
> Furthermore, since this is a command line warning and not a compiler
> warning, it cannot be suppressed.  Unless you have any better ideas on how
> to address this, I think this should be reverted.

That's strange -- I fetched today, reran cmake, and am not seeing
those command line warnings when I build with MSVC 2013. What compile
target are you seeing those warnings triggered on?

~Aaron