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    SubjectRe: [PATCH v2 1/2] scripts: Add a recorduidiv program
    On Tue, Dec 01, 2015 at 05:07:05PM +0100, Michal Marek wrote:
    > On 2015-11-30 16:40, Michal Marek wrote:
    > > On 2015-11-30 16:32, Russell King - ARM Linux wrote:
    > >> On Mon, Nov 30, 2015 at 04:11:16PM +0100, Michal Marek wrote:
    > >>> On 2015-11-26 00:47, Russell King - ARM Linux wrote:
    > >>>> Do we have any resolution on these programs which modify the object
    > >>>> files in-place, rather than breaking any hard-links which may be
    > >>>> present (eg, as a result of using ccache in hard-link mode) ?
    > >>>
    > >>> Good point, but I do not think anybody is using CCACHE_HARDLINK with the
    > >>> kernel.
    > >>
    > >> That's wrong then, because I've been using it for a very long time with
    > >> my nightly builds. :) Therefore, there is somebody!
    > >
    > > OK.
    >
    > So, both recordmcount and the new recordudiv program are idempotent.
    > They check if the to-be-added section is already present and do nothing.

    They hardly "do nothing", as the (eg) recordmcount plasters the build
    log with warnings. A solution to that would be to make recordmcount
    silent if the section is already present.

    > So the result is correct even with CCACHE_HARDLINK, just the
    > intermediate file might be incorrect. If this still is considered an
    > issue, I suggest clearing CCACHE_HARDLINK when using any of these
    > postprocessors, so as not to penalize other use cases.

    Another solution would be to have the top level make file unset the
    CCACHE_HARDLINK environment variable if any of the options which enable
    in-place editing of object files is enabled. Looking at the ccache
    code, the environment variable has to be deleted from the environment
    to turn off the option - and I'm not sure whether make can delete
    environment variables. It certainly can override them, but I see
    nothing in the info pages which suggests that environment variables
    can be deleted by a makefile.

    However, doing it outside of the kernel build system is likely error
    prone especially as the kernel configuration options change and/or
    their effect changes.

    --
    FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
    according to speedtest.net.


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