patchtests: make SANITIZE=address imply TEST_NO_MALLOC_CHECK

> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> As the address sanitizer checks for a superset of the issues detected
> by setting MALLOC_CHECK_ (which tries to detect things like double
> frees and off-by-one errors) there is no need to set the latter when
> compiling with -fsanitize=address.

> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> As the address sanitizer checks for a superset of the issues detected
> by setting MALLOC_CHECK_ (which tries to detect things like double
> frees and off-by-one errors) there is no need to set the latter when
> compiling with -fsanitize=address.
>
> This fixes a regression introduced by 131b94a10a ("test-lib.sh: Use
> GLIBC_TUNABLES instead of MALLOC_CHECK_ on glibc >= 2.34", 2022-03-04)
> which causes all the tests to fail with the message
>
>     ASan runtime does not come first in initial library list;
>     you should either link runtime to your application or
>     manually preload it with LD_PRELOAD.
>
> when git is compiled with SANITIZE=address on systems with glibc >=
> 2.34. I have tested SANITIZE=leak and SANITIZE=undefined and they do
> not suffer from this regression so the fix in this patch should be
> sufficient.
>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---
>     tests: make SANITIZE=address imply TEST_NO_MALLOC_CHECK
>     
>     I'm submitting this now as it fixes a regression introduced in the
>     current cycle. Having said that there is an easy workaround (once one
>     has discovered GIT_TEST_NO_MALLOC_CHECK) so I'd be happy to wait until
>     the start of the next cycle given I've just missed -rc1.

> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1210%2Fphillipwood%2Fwip%2Ftest-malloc-asan-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1210/phillipwood/wip/test-malloc-asan-v1
> Pull-Request: https://github.com/gitgitgadget/git/pull/1210
>
>  Makefile      | 5 ++++-
>  t/test-lib.sh | 5 +++--
>  2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 91738485626..76d187991d2 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1267,8 +1267,9 @@ PTHREAD_CFLAGS =
>  SPARSE_FLAGS ?= -std=gnu99
>  SP_EXTRA_FLAGS = -Wno-universal-initializer
>  
> -# For informing GIT-BUILD-OPTIONS of the SANITIZE=leak target
> +# For informing GIT-BUILD-OPTIONS of the SANITIZE=leak,address targets
>  SANITIZE_LEAK =
> +SANITIZE_ADDRESS =
>  
>  # For the 'coccicheck' target; setting SPATCH_BATCH_SIZE higher will
>  # usually result in less CPU usage at the cost of higher peak memory.
> @@ -1314,6 +1315,7 @@ SANITIZE_LEAK = YesCompiledWithIt
>  endif
>  ifneq ($(filter address,$(SANITIZERS)),)
>  NO_REGEX = NeededForASAN
> +SANITIZE_ADDRESS = YesCompiledWithIt
>  endif
>  endif
>  
> @@ -2861,6 +2863,7 @@ GIT-BUILD-OPTIONS: FORCE
>  	@echo PAGER_ENV=\''$(subst ','\'',$(subst ','\'',$(PAGER_ENV)))'\' >>$@+
>  	@echo DC_SHA1=\''$(subst ','\'',$(subst ','\'',$(DC_SHA1)))'\' >>$@+
>  	@echo SANITIZE_LEAK=\''$(subst ','\'',$(subst ','\'',$(SANITIZE_LEAK)))'\' >>$@+
> +	@echo SANITIZE_ADDRESS=\''$(subst ','\'',$(subst ','\'',$(SANITIZE_ADDRESS)))'\' >>$@+

> -# Add libc MALLOC and MALLOC_PERTURB test
> -# only if we are not executing the test with valgrind
> +# Add libc MALLOC and MALLOC_PERTURB test only if we are not executing
> +# the test with valgrind and have not compiled with SANITIZE=address.
>  if test -n "$valgrind" ||
> +   test -n "$SANITIZE_ADDRESS" ||
>     test -n "$TEST_NO_MALLOC_CHECK"
>  then
>  	setup_malloc_check () {

> I wonder why we have to justify that we'll only turn on
> TEST_NO_MALLOC_CHECK if it's SANITIZE=address.
>
> I.e. we also have SANITIZE=undefined, wouldn't it be more future-proof
> to just say that these analysis options are mutually exclusive by
> default?

> Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:
>
>> I wonder why we have to justify that we'll only turn on
>> TEST_NO_MALLOC_CHECK if it's SANITIZE=address.
>>
>> I.e. we also have SANITIZE=undefined, wouldn't it be more future-proof
>> to just say that these analysis options are mutually exclusive by
>> default?
>
> Given that the SANITIZE mechanism itself allows more than one to be
> requested at the same time, it is unclear to me why other checks
> like undefined needs to exclude checks done by other mechanisms like
> MALLOC_CHECK_ by default.  If I correctly read under-the-three-dash
> commentary Phillip wrote, it's not like that use of MALLOC_CHECK_
> inherently interferes with the way SANITIZE=undefined wants to work,
> no?