https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69555
Bug ID: 69555
Summary: libgomp.c++/target-6.C fails because of undefined
behaviour
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgomp
Assignee: unassigned at gcc dot gnu.org
Reporter: vogt at linux dot vnet.ibm.com
CC: jakub at gcc dot gnu.org, krebbel at gcc dot gnu.org
Target Milestone: ---
Target: s390x
The test case libgomp.c++/target-6.C fails on s390x, and I think that's because
it uses a reference type variable in a "private" construct:
-- snip --
...
int a[y - 2], b[y - 2];
int (&c)[y - 2] = a, (&d)[y - 2] = b;
^^^^^^^^^^^^^^^
...
#pragma omp target private (x, u, s, c, i) firstprivate (y, v, t, d)
map(from\
:err)
^^^
{
...
for (i = 0; i < y - 2; i++)
c[i] = d[i];
...
}
...
-- snip --
Depending on optimisations and the rest of the code, this leads to either
incorrect values in the array "a" or accessing a pointer to random memory.
As far as I understand it, the "OpenMP Application Program Interface, Version
4.0 - July 2013" explicitly forbids this on page 161:
28 • A variable that appears in a private clause must not have an incomplete
type or a
29 reference type.
