Re: headerscheck ccache support

On 22.11.25 09:54, Thomas Munro wrote:
> On Fri, Nov 21, 2025 at 11:48 PM Peter Eisentraut <peter@eisentraut.org> wrote:
>> Currently, headerscheck and cpluspluscheck are very slow, and they
>> defeat use of ccache.  I have fixed that, and now they are much faster. :-)
>>
>> The problem was (I think) that the test files are created in a
>> randomly-named directory (`mktemp -d /tmp/$me.XXXXXX`), and this
>> directory is named on the compiler command line, which is part of the
>> cache key.
>>
>> My solution is to create the test files in the build directory.  For
>> example, for src/include/storage/ipc.h I generate
>>
>> headerscheck_src_include_storage_ipc_h.c (or .cpp)
>>
>> Now ccache works.  (And it's also a bit easier to debug everything with
>> this naming.)
>>
>> The observed speedup on Cirrus CI for headerscheck plus cpluspluscheck
>> is from about 1min 20s to only 20s.  In local use, the speedups are similar.
> 
> +1
> 
> I wrote an almost identical patch[1] and then lost it down the back of
> the sofa.  I was wondering about parallelising it next...
> 
> [1] https://www.postgresql.org/message-id/CA%2BhUKGJjQyZUvcu6udk5OKz5rnaF4a_hm5nb_VtZHYMH%2BvsN0g%40mail.gmail.com

Ah yes, that's about the same idea.  The difference is that yours 
requires specifying TMPDIR on the make invocation.  So it wouldn't 
happen by default for local (non-CI) use.  I think I would like an 
implementation that also worked out of the box locally.