Re: [PATCH] Turn some compile-time tests into run-time tests

[Jeff Law <law@redhat.com>]

On 03/10/2016 04:38 PM, Patrick Palka wrote:
> I ran the command
>
>   git grep -l "dg-do compile" | xargs grep -l __builtin_abort | xargs grep -lw main
>
> to find tests marked as compile-time tests that likely ought to instead
> be marked as run-time tests, by the rationale that they use
> __builtin_abort and they also define main().  (I also then confirmed that they
> compile, link and run cleanly on my machine.)
>
> After this patch, the remaining test files reported by the above command
> are:
>
>   These do not define all the functions they use:
>     gcc/testsuite/g++.dg/ipa/devirt-41.C
>     gcc/testsuite/g++.dg/ipa/devirt-44.C
>     gcc/testsuite/g++.dg/ipa/devirt-45.C
>     gcc/testsuite/gcc.target/i386/pr55672.c
>
>   These are non-x86 tests so I can't confirm that they run cleanly:
>     gcc/testsuite/gcc.target/arm/pr58041.c
>     gcc/testsuite/gcc.target/powerpc/pr35907.c
>     gcc/testsuite/gcc.target/s390/dwarfregtable-1.c
>     gcc/testsuite/gcc.target/s390/dwarfregtable-2.c
>     gcc/testsuite/gcc.target/s390/dwarfregtable-3.c
>
>   These use dg-error:
>     libstdc++-v3/testsuite/20_util/forward/c_neg.cc
>     libstdc++-v3/testsuite/20_util/forward/f_neg.cc
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK to
> commit?  Does anyone have another heuristic one can use to help find
> these kinds of typos?
>
> gcc/testsuite/ChangeLog:
>
> 	* g++.dg/cpp0x/constexpr-aggr2.C: Make it a run-time test.
> 	* g++.dg/cpp0x/nullptr32.C: Likewise.
> 	* g++.dg/cpp1y/digit-sep-cxx11-neg.C: Likewise.
> 	* g++.dg/cpp1y/digit-sep.C: Likewise.
> 	* g++.dg/ext/flexary13.C: Likewise.
> 	* gcc.dg/alias-14.c: Likewise.
> 	* gcc.dg/ipa/PR65282.c: Likewise.
> 	* gcc.dg/pr69644.c: Likewise.
> 	* gcc.dg/tree-ssa/pr38533.c: Likewise.
> 	* gcc.dg/tree-ssa/pr61385.c: Likewise.
My worry with the 38533 test is that while the ASM defines "f" from the 
standpoint of dataflow, it does not actually emit any code to ensure "f" 
is actually defined.  This could lead to spurious aborts due to use of 
an uninitialized value at runtime.  Similarly for alias-14.c

I'd be worried that we don't necessarily have sync_bool_compare_and_swap 
on all targets for 69644.

flexary13.C probably won't link on a cross target unless the cross 
libraries are available.  But that's probably OK.

The rest seem OK to me.  Note that I'm not convinced all these tests 
were designed to be execution tests, even though they use 
__builtin_abort and friends.  Though it's a good marker of something 
that can/should be looked at.


jeff