| Message ID | ce5f3834-ae3e-910d-c491-57be64a04188@suse.cz |
|---|---|
| State | New |
| Headers | show |
| Series | Bail out in gfc_dep_compare_expr for a NULL argument. | expand |
Hi Martin, On 12/10/19 2:04 PM, Martin Liška wrote: > The patch is about early bail out in gfc_dep_compare_expr function > when one of the arguments (and not both at the same time) is null. > I'm not sure, it's a proper fix however. I think it is the best one can do. Technically, one could replace the comparison by "length == 1 || "" == x(1:)" but I am not sure whether that would be be advantageous in general (esp. when taking implementation time into account); in any case, that's independent of the ICE. The caller in this example is "are_identical_variables": if (gfc_dep_compare_expr (r1->u.ss.end, r2->u.ss.end) != 0) return false; comparing the string end. And "-2 if the relationship could not be determined". > Patch can bootstrap on x86_64-linux-gnu and survives regression tests. > > Ready to be installed? Yes; it looks good to me – thanks! Tobias > gcc/fortran/ChangeLog: > > 2019-12-10 Martin Liska <mliska@suse.cz> > > PR fortran/92874 > * dependency.c (gfc_dep_compare_expr): Bail out > when one of the arguments is null. > > gcc/testsuite/ChangeLog: > > 2019-12-10 Martin Liska <mliska@suse.cz> > > PR fortran/92874 > * gfortran.dg/pr92874.f90: New test. > --- > gcc/fortran/dependency.c | 2 ++ > gcc/testsuite/gfortran.dg/pr92874.f90 | 11 +++++++++++ > 2 files changed, 13 insertions(+) > create mode 100644 gcc/testsuite/gfortran.dg/pr92874.f90 > >
diff --git a/gcc/fortran/dependency.c b/gcc/fortran/dependency.c index 394d85b48a2..eb741137d60 100644 --- a/gcc/fortran/dependency.c +++ b/gcc/fortran/dependency.c @@ -319,6 +319,8 @@ gfc_dep_compare_expr (gfc_expr *e1, gfc_expr *e2) if (e1 == NULL && e2 == NULL) return 0; + else if (e1 == NULL || e2 == NULL) + return -2; e1 = gfc_discard_nops (e1); e2 = gfc_discard_nops (e2); diff --git a/gcc/testsuite/gfortran.dg/pr92874.f90 b/gcc/testsuite/gfortran.dg/pr92874.f90 new file mode 100644 index 00000000000..a1fca3d7718 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/pr92874.f90 @@ -0,0 +1,11 @@ +! { dg-do compile } +! { dg-options "-O2" } +! PR fortran/92874 +program p + call s('a') + call s('abc') +end +subroutine s(x) + character(*) :: x + print *, (x(1:1) == x(1:)) +end