Re: [PATCH v3] ld: add --package-metadata

[Alan Modra <amodra@gmail.com>]

On Wed, May 25, 2022 at 02:41:47PM +0100, luca.boccassi@gmail.com wrote:
> From: Luca Boccassi <bluca@debian.org>
> 
> Generate a .note.package FDO package metadata ELF note, following
> the spec: https://systemd.io/ELF_PACKAGE_METADATA/
> 
> If the jansson library is available at build time (and it is explicitly
> enabled), link ld to it, and use it to validate that the input is
> correct JSON, to avoid writing garbage to the file. The
> configure option --enable-jansson has to be used to explicitly enable
> it (error out when not found). This allows bootstrappers (or others who
> are not interested) to seamlessly skip it without issues.
> ---
> v2: fix style issues
>     fix ASAN issue: note storage is rounded up, but that size
>     was used to read the json input, which is fixed
>     add entry to NEWS
>     add note about json validation to docs
> v3: switch libjansson support to disabled-by-default even if
>       the library is available in the build environment
>     update new test to account for old/new readelf, which
>       might or might not pretty-print the FDO note
>     update bootstrap test to link with jansson if the object
>       files being linked were built with it
>     remove dead code

I'm about to commit this with a few formatting fixes, and with a
working bootstrap.exp change.  That one was obviously not tested.  The
idea was good but ld config.h is not in $srcdir/.., and besides that
it's on the build machine not the host (*), and plain grep is more
likely to exist than fgrep.

*) build vs host doesn't matter much in bootstrap.exp since those
tests are only run when native, but I'd like to get it correct for
someone doing copy/paste for a future config.h test.

-- 
Alan Modra
Australia Development Lab, IBM