[OE-core] [Yocto] The design document for ccache-native

[Richard Purdie]

On Thu, 2011-06-09 at 15:40 -0700, Saul Wold wrote:
> On 06/02/2011 08:11 PM, wenzong fan wrote:
> > Hi Folks,
> >
> > Please help me to review the design document for ccache-native, and
> > I also have two questions about it, any answers or suggestions are
> > appreciated.
> >
> > * Feature name: ccache-native
> >     Priority: P3; M2
> >     Owner: Wenzong Fan
> >     Summary: Integrate ccache-native to yocto
> >
> > * Description:
> > Bitbake supports the 'CCACHE Mechanism', but 'ccache' hasn't been
> > included by poky/yocto, just add it as a native tool.
> >
> > * Usage:
> > Build ccache as a native tool by default and enable it for speeding
> > target packages build.
> >
> > * Implementation:
> > 1) Copy bb file from OE upstream to:
> >       meta/recipes-devtools/ccache/
> >
> > 2) Update bb file to get the latest ccache_3.1.5 and split the single
> > bb file to:
> >       'ccache_3.1.5.bb', 'ccache.inc'
> >
> > 3) Enable ccache in the native tools building.
> >
> You will need to have it be a dependency pretty early on in the build.
> Additionally, this is a bit a new part to this task, we want to have the 
> default CCACHE_DIR for the build default to a directory in TMPDIR 
> instead of the user's home directory.  This will mean setting an 
> environment variable somewhere early also.

There is a little more detail on:

https://wiki.yoctoproject.org/wiki/Yocto_1.1_Schedule

Specifically, "c) Set CCACHE on a per recipe basis. need to figure out
whether ccache data can be shared and under what circumstances."

so something like adding:

export CCACHE_DIR = "${TMPDIR}/ccache/${TARGET_SYS}/${PN}"

to bitbake.conf with a bit more thought into working out the right
components to add to the variable.

Cheers,

Richard