[ccache] ccacje direct mode without fall back to running the preprocessor

vkr venkatakrishnarao.ks at gmail.com
Fri Sep 5 03:21:08 MDT 2014

First of all, sorry about the typo in the subject/title of my post.

I run ccache in read-only mode itself. But, I still see that after the
direct cache lookup fail, it falls back to running the preprocessor.
That's exactly what I wanted to avoid.

It seems to me that having an option to avoid preprocessing after a
direct-cache-lookup fail is still a very valid option if the user
knows that preprocesor will result in a failure/he purposefully wants
to avoid it.
I hope my justification is valid.

 88 [2014-09-05T14:45:17.445383 25208] Hostname: host.myhost.net
 89 [2014-09-05T14:45:17.445393 25208] Working directory: (null)
 90 [2014-09-05T14:45:17.445399 25208] Base directory:
 91 [2014-09-05T14:45:17.445734 25208] Source file: ../my_source.cpp
 92 [2014-09-05T14:45:17.445745 25208] Dependency file: ../my_source.d
 93 [2014-09-05T14:45:17.445752 25208] Object file: ../my_source.cpp.o
 94 [2014-09-05T14:45:17.447011 25208] Trying direct lookup
 95 [2014-09-05T14:45:17.447167 25208] Looking for object file hash in
 96 [2014-09-05T14:45:17.479757 25204] Looking for object file hash in
 97 [2014-09-05T14:45:17.863524 25194] Did not find object file hash in manifest
 98 [2014-09-05T14:45:17.864854 25194] Running preprocessor


On Fri, Sep 5, 2014 at 1:51 AM, Andrew Stubbs <ams at codesourcery.com> wrote:
> On 04/09/14 08:32, vkr wrote:> I would like to know if I can avoid
>> "If there is no match, ccache falls back to running the preprocessor."
> The answer is "no", because it is necessary to run the preprocessor in order
> to fill the cache and record the file list that direct mode lookups use.
> It might be possible if you wanted to run the cache in read-only mode, but
> that might not be very useful, and I don't believe there's an option for
> that now.
> Andrew

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