Re: [PATCH] Remove broken testcase gcc.c-torture/execute/20020619-1.c

[Ian Lance Taylor <iant at google dot com>]

Richard Guenther <rguenther@suse.de> writes:

> Maybe I'm missing something obvious, but the testcase
> gcc.c-torture/execute/20020619-1.c invokes undefined behavior in
> test(), as *(int *)c references c through an incompatible lvalue.
>
> In particular 6.5/7 doesn't make the object type special, but only
> the lvalue type.  And the effective type of c is char (its declared
> type).  And clearly char and int are not compatible either.
>
> But well...  ok for mainline?  (this is the single testcase that
> "breaks" if we fix PR36345, the TBAA-pruning of points-to sets)

For what it's worth, that test case was added here, without a
ChangeLog entry:

http://gcc.gnu.org/ml/gcc-patches/2002-06/msg01730.html

Interestingly, the invalid part of the test is not what Richard
Henderson was actually trying to test.  He was fixing a bug which
caused ref to return the wrong value, and wrote test to try to get the
endian-independent value which ref was supposed to return.

It would probably suffice to change main to check that ref returns
either 0x01020304 or 0x04030201.

Ian