[cfe-dev] adding FileSkipped() to PPCallbacks

[Zhanyong Wan (λx.x x)]

Thanks for the review, Chris.  Please see the new patch.  I kept the
signature of FileSkipped() unchanged to be consistent with
FileChanged().

On Fri, Apr 16, 2010 at 1:34 PM, Chris Lattner <clattner at apple.com> wrote:
>
> On Apr 16, 2010, at 11:48 AM, Zhanyong Wan (λx.x x) wrote:
>
>> Hi Doug,
>>
>> Per our IRC chat yesterday, I'm extending PPCallbacks with a new
>> method FileSkipped() to notify a listener when a #include is skipped
>> due to header guard optimization.  Please see the attached patch and
>> let me know if this is the right direction.  (I verified that it works
>> for my use case.)  Also, how should I add a test for this?
>
> The .h file change look fine to me, but it isn't good to sink the check below SourceMgr.createFileID.  Skipping headers is a fairly hot path, so we don't want it to do additional work when ppcallbacks aren't being used.
>
> Please change the callback to take the FileEntry or some other information that doesn't require sinking the check below the potentially expensive work.
>
> -Chris



-- 
Zhanyong
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