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Date:   Thu, 13 Jan 2022 18:34:20 -0800
From:   "Andy Lutomirski" <luto@kernel.org>
To:     "Florian Weimer" <fweimer@redhat.com>
Cc:     linux-arch@vger.kernel.org,
        "Linux API" <linux-api@vger.kernel.org>,
        linux-x86_64@vger.kernel.org, kernel-hardening@lists.openwall.com,
        linux-mm@kvack.org, "the arch/x86 maintainers" <x86@kernel.org>,
        musl@lists.openwall.com,
        "Dave Hansen via Libc-alpha" <libc-alpha@sourceware.org>,
        "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
        "Dave Hansen" <dave.hansen@intel.com>,
        "Kees Cook" <keescook@chromium.org>,
        "Andrei Vagin" <avagin@gmail.com>
Subject: Re: [PATCH v3 2/3] selftests/x86/Makefile: Support per-target $(LIBS)
 configuration
Content-Type: text/plain
Precedence: bulk

On Thu, Jan 13, 2022, at 2:00 PM, Florian Weimer wrote:
> * Andy Lutomirski:
>
>> On 1/5/22 08:03, Florian Weimer wrote:
>>> And avoid compiling PCHs by accident.
>>> 
>>
>> The patch seems fine, but I can't make heads or tails of the
>> $SUBJECT. Can you help me?
>
> What about this?
>
> selftests/x86/Makefile: Set linked libraries using $(LIBS)
>
> I guess that it's possible to use make features to set this per target
> isn't important.

I think that's actually important -- it's nice to explain to make dummies (e.g. me) what the purpose is is.  I assume it's so that a given test can override the libraries.  Also, you've conflated two different changes into one patch: removal of .h and addition of LIBS.

--Andy


>
> Thanks,
> Florian
>
>>> Signed-off-by: Florian Weimer <fweimer@redhat.com>
>>> ---
>>> v3: Patch split out.
>>>   tools/testing/selftests/x86/Makefile | 6 ++++--
>>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>> diff --git a/tools/testing/selftests/x86/Makefile
>>> b/tools/testing/selftests/x86/Makefile
>>> index 8a1f62ab3c8e..0993d12f2c38 100644
>>> --- a/tools/testing/selftests/x86/Makefile
>>> +++ b/tools/testing/selftests/x86/Makefile
>>> @@ -72,10 +72,12 @@ all_64: $(BINARIES_64)
>>>   EXTRA_CLEAN := $(BINARIES_32) $(BINARIES_64)
>>>     $(BINARIES_32): $(OUTPUT)/%_32: %.c helpers.h
>>> -	$(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl -lm
>>> +	$(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $(filter-out %.h, $^) \
>>> +		$(or $(LIBS), -lrt -ldl -lm)
>>>     $(BINARIES_64): $(OUTPUT)/%_64: %.c helpers.h
>>> -	$(CC) -m64 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl
>>> +	$(CC) -m64 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $(filter-out %.h, $^) \
>>> +		$(or $(LIBS), -lrt -ldl -lm)
>>>     # x86_64 users should be encouraged to install 32-bit libraries
>>>   ifeq ($(CAN_BUILD_I386)$(CAN_BUILD_X86_64),01)