Hi Matthew,
> The current no_fsanitize_address effective target check (implemented in
> target-supports.exp rather than in asan.exp) has some problems with the
> link path.
>
> Because it is not called from in between asan_init and asan_finish the
> link paths of the compiler are not changed to point at the build
> directories.
>
> That means that they point at the install directory that the current
> build is configured for. Hence this test passes if the current compiler
> has ASAN support *and* if there are ASAN libraries in the directory that
> this build is configured to install into.
>
> That is an unnecessary requirement. On looking through each of the
> tests that currently use no_fsanitize_address it seems all are `compile`
> tests. Hence we can change the logical test of the effective target
> from "can we link an ASAN executable" to "can we compile for ASAN" and
> avoid the need to set up link paths correctly for this test.
>
> N.b. one alternative would be to remove this effective target and try to
> move all tests which currently use this into directories which run their
> tests between calls to `asan_finish` and `asan_init`. This seems like
> it might ensure a clearer division of "asan tests must be run in X
> directories" and avoid problems similar to the one here in the future.
> I'm suggesting this change as it appears the easiest to make and I
> didn't think the above too bad a risk to take -- especially if the name
> of the test is clear.
moving the tests would be clearer IMO, otherwise we have two separate
mechanisms for the same issue. Especially since we're talking about 7
tests only. The only complication would be the aarch64 test where
there's currently no asan subdir.
> In doing this I also inverted the meaning of this check. Rather than
> the function indicating whether we *do not* support something and
> tests using `dg-skip-if` to avoid running a test if this returns true,
> this function indicates whether we *do* support something and tests
> use `dg-require-effective-target` to run a test if it returns true.
>
> Testing done by checking that each of the affected testcases changes
> from UNSUPPORTED to PASS when run individually without any install
> directory available.
Please remember to state on which target you've run the tests.
> gcc/testsuite/ChangeLog:
>
> * g++.dg/warn/uninit-pr93100.C: Convert no_fsanitize_address use
> to fsanitize_address_compilation.
*If* we go this route (and as I said I'd prefer not to; maybe Mike
differs), please rename the new keyword to fsanitize_address_compile in
line with e.g. "dg-do compile". You also would need to adjust
sourcebuild.texi for the change.
> diff --git a/gcc/testsuite/lib/target-supports.exp
> b/gcc/testsuite/lib/target-supports.exp
> index
> d3edc7d839ec2d9460501c157c1129176542d870..d9ea048d01212c4d28e68860a38c523cea8f2393
> 100644
> --- a/gcc/testsuite/lib/target-supports.exp
> +++ b/gcc/testsuite/lib/target-supports.exp
> @@ -13166,16 +13166,16 @@ proc check_effective_target_movdir { } {
> } "-mmovdiri -mmovdir64b" ]
> }
>
> -# Return 1 if the target does not support address sanitizer, 0 otherwise
> +# Return 1 if the target supports address sanitizer, 0 otherwise
Comment needs adjustment, too.
Rainer
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Rainer Orth, Center for Biotechnology, Bielefeld University
