[RFC/PATCH] buildsys: cache build flags in vars

[Khem Raj]

On Mon, Jan 16, 2012 at 3:06 PM, Khem Raj <raj.khem at gmail.com> wrote:
> On Mon, Jan 16, 2012 at 2:19 PM, Mike Frysinger <vapier at gentoo.org> wrote:
>> On Monday 16 January 2012 14:17:52 Khem Raj wrote:
>>> On Mon, Jan 16, 2012 at 10:00 AM, Khem Raj <raj.khem at gmail.com> wrote:
>>> > On Sat, Nov 26, 2011 at 9:22 PM, Mike Frysinger <vapier at gentoo.org> wrote:
>>> >> Running `make clean` atm takes like 20 seconds because every subdir
>>> >> re-evaluates all the toolchain flags.  Add some helpers to automate
>>> >> the process of setting up variables to cache the result of tests,
>>> >> as well as the checking of an already set flag.
>>> >>
>>> >> Now `make clean` takes like 2 seconds on my system.
>>>
>>> -Wl,sort-section,alignment also seems to be computed wrongly in CFLAGS
>>
>> i just pushed a fix.  could you give it a try ?
>
> it fixes the first problem where CFLAG_-Wl and CFLAGS_-Wa
> were not exported but does not address isssues when options have multiple words
>
> eg. linker option --sort-sections alignment if passed via gcc driver
> is passed as
> -Wl,--sort-sections -Wl,alignment
>
> your code does not handle such a case and unfortunately we use
> --sort-sections alignment in uclibc build

we can use the long version of option --sort-section=alignment
in Rules.mak and that will work fine but I think it is a limitation
that should be addressed
rather than work arounded.

>
>
>> -mike