[PATCH] D36492: [RFC][time-report] Add preprocessor timer

[Brian Gesiak via Phabricator via cfe-commits]

modocache added a reviewer: vsk.
modocache planned changes to this revision.
modocache added a comment.

Thanks for the feedback, @vsk, I really appreciate it! I have some other work done for this on my local checkout, but I was going a little bonkers working on it without knowing whether people would want it merged or not. I'll update this with your feedback and upload the rest for review as well.

> It'd be nice to dump this timer from Preprocessor::PrintStats(), too.

Good idea, will do!



================
Comment at: lib/Lex/Preprocessor.cpp:660
 
+  llvm::TimeRegion(PPOpts->ShowTimers ? &PreprocessingTimer : nullptr);
+
----------------
vsk wrote:
> vsk wrote:
> > I wonder whether this is too fine-grained. I think setting up a timer in Preprocessor::Lex() might capture more information. Would you mind experimenting with that?
> Nitpick: it may be useful to add PPOpts::getTimer(), in case we find more sites where we need to either get back the PP timer or nullptr.
> I think setting up a timer in `Preprocessor::Lex()` might capture more information.

Yes, can do! As it happens, the timers in this current diff cover all of the event counters that are incremented and then printed in  `Preprocessor::PrintStats()`, except two: `NumTokenPaste` and `NumFastTokenPaste`. Beginning the timer in the Lexer would allow me to measure the time it takes to do token pasting as well, so I think this is a great idea. Thanks!

> it may be useful to add `PPOpts::getTimer()`

Agreed, will do!


https://reviews.llvm.org/D36492