Creating one large precompiled header from multitude of other (possibly also precompiled) headers.

[Andy Falanga (afalanga)]

On 03/31/2016 05:12 PM, leon zadorin wrote:
> Hello and pardon the nativity of question given that I didn't look at
> the internals of GCC's precompiled header implementation...
>
> I am aware that GCC considers a precompiled header file (e.g. x.h.gch)
> when looking for a usual, included, header file (e.g. #include "x.h").
>
> So the question is: when creating one large precompiled header such as
> all.h.gch where all.h #includes x.h, y.h, z.h, etc. -- will GCC be
> able to accelerate the process of creating all.h.gch if it sees that
> x.h itself already has a precompiled version such as x.h.gch?
>
> Best regards
> Leon.
There are others here who know better than I.  That said, from this link 
to gcc docs: 
https://gcc.gnu.org/onlinedocs/gcc-4.8.5/gcc/Precompiled-Headers.html#Precompiled-Headers 
, I would say: no.  Consider:

* Only one precompiled header can be used in a particular compilation.

This is the very first bullet in the docs when they discuss restrictions.

Andy