@Bruce, see below.
On 7/1/21 3:34 PM, David Marchand wrote:
> On Thu, Jul 1, 2021 at 11:22 AM Andrew Rybchenko
> <andrew.rybche...@oktetlabs.ru> wrote:
>> The build works fine for me on FC34, but it has
>> libatomic-11.1.1-3.fc34.x86_64 installed.
>
> I first produced the issue on my "old" FC32.
> Afaics, for FC33 and later, gcc now depends on libatomic and the
> problem won't be noticed.
> FC32 and before are EOL, but I then reproduced the issue on RHEL 8
> (and Intel CI reported it on Centos 8 too).
I see. Thanks for the clarification.
>>
>> I'd like to understand what we're trying to solve here.
>> Are we trying to make meson to report the missing library
>> correctly?
>>
>> If so, I think I can do simple check using cc.links()
>> which will fail if the library is not found. I'll
>> test that it works as expected if the library is not
>> completely installed.
>>
>
> I tried below diff, and it works for me.
> "works" as in net/sfc gets disabled without libatomic installed:
>
> diff --git a/drivers/net/sfc/meson.build b/drivers/net/sfc/meson.build
> index 32b58e3d76..8d62aad774 100644
> --- a/drivers/net/sfc/meson.build
> +++ b/drivers/net/sfc/meson.build
> @@ -15,6 +15,7 @@ endif
> if (arch_subdir != 'x86' or not dpdk_conf.get('RTE_ARCH_64')) and
> (arch_subdir != 'arm' or not
> host_machine.cpu_family().startswith('aarch64'))
> build = false
> reason = 'only supported on x86_64 and aarch64'
> + subdir_done()
@Bruce Shouldn't we add subdir_done() after all build = false
cases? As I understand it is OK for minimum supported meson
version.
> endif
>
> extra_flags = []
> @@ -46,6 +47,14 @@ endif
>
> # for gcc compiles we need -latomic for 128-bit atomic ops
> if cc.get_id() == 'gcc'
> + code = '''#include <stdio.h>
> + void main() { printf("Atomilink me.\n"); }
> + '''
> + if not cc.links(code, args: '-latomic', name: 'libatomic link check')
> + build = false
> + reason = 'missing dependency, "libatomic"'
> + subdir_done()
> + endif
> ext_deps += cc.find_library('atomic')
> endif
Many thanks, LGTM. I'll pick it up and add comments why
it is checked this way.
