[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

janus at gcc dot gnu.org changed:

   What|Removed |Added

 Status|ASSIGNED|RESOLVED
 Resolution|--- |FIXED

--- Comment #11 from janus at gcc dot gnu.org ---
(In reply to janus from comment #8)
> I'll backport the fix to the release branches soon if no problems appear on
> trunk.

Both backports have been applied by now. Thus, the problem is fixed for the
upcoming releases 5.5, 6.3 and 7.0.

Closing. Thanks for the report!

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

--- Comment #10 from janus at gcc dot gnu.org ---
Author: janus
Date: Wed Nov 23 16:46:31 2016
New Revision: 242770

URL: https://gcc.gnu.org/viewcvs?rev=242770=gcc=rev
Log:
2016-11-23  Janus Weil  

Backport from trunk
PR fortran/66227
* simplify.c (gfc_simplify_extends_type_of): Fix missed optimization.
Prevent over-simplification. Fix a comment. Add a comment.

2016-11-23  Janus Weil  

Backport from trunk
PR fortran/66227
* gfortran.dg/extends_type_of_3.f90: Fix and extend the test case.

Modified:
branches/gcc-5-branch/gcc/fortran/ChangeLog
branches/gcc-5-branch/gcc/fortran/simplify.c
branches/gcc-5-branch/gcc/testsuite/ChangeLog
branches/gcc-5-branch/gcc/testsuite/gfortran.dg/extends_type_of_3.f90

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

--- Comment #9 from janus at gcc dot gnu.org ---
Author: janus
Date: Wed Nov 23 16:26:38 2016
New Revision: 242768

URL: https://gcc.gnu.org/viewcvs?rev=242768=gcc=rev
Log:
2016-11-23  Janus Weil  

Backport from trunk
PR fortran/66227
* simplify.c (gfc_simplify_extends_type_of): Fix missed optimization.
Prevent over-simplification. Fix a comment. Add a comment.

2016-11-23  Janus Weil  

Backport from trunk
PR fortran/66227
* gfortran.dg/extends_type_of_3.f90: Fix and extend the test case.

Modified:
branches/gcc-6-branch/gcc/fortran/ChangeLog
branches/gcc-6-branch/gcc/fortran/simplify.c
branches/gcc-6-branch/gcc/testsuite/ChangeLog
branches/gcc-6-branch/gcc/testsuite/gfortran.dg/extends_type_of_3.f90

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

Jeffrey A. Law  changed:

   What|Removed |Added

   Priority|P3  |P4
 CC||law at redhat dot com

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

janus at gcc dot gnu.org changed:

   What|Removed |Added

  Known to work||4.5.0
   Target Milestone|--- |5.5
  Known to fail||5.4.1, 6.2.0

--- Comment #8 from janus at gcc dot gnu.org ---
Fixed on trunk with r242535. For more discussion of the fix see the thread
starting at https://gcc.gnu.org/ml/fortran/2016-11/msg00150.html.

I'll backport the fix to the release branches soon if no problems appear on
trunk.

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

--- Comment #7 from janus at gcc dot gnu.org ---
Author: janus
Date: Thu Nov 17 07:52:24 2016
New Revision: 242535

URL: https://gcc.gnu.org/viewcvs?rev=242535=gcc=rev
Log:
2016-11-17  Janus Weil  

PR fortran/66227
* simplify.c (gfc_simplify_extends_type_of): Fix missed optimization.
Prevent over-simplification. Fix a comment. Add a comment.

2016-11-17  Janus Weil  

PR fortran/66227
* gfortran.dg/extends_type_of_3.f90: Fix and extend the test case.

Modified:
trunk/gcc/fortran/ChangeLog
trunk/gcc/fortran/simplify.c
trunk/gcc/testsuite/ChangeLog
trunk/gcc/testsuite/gfortran.dg/extends_type_of_3.f90

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

--- Comment #6 from janus at gcc dot gnu.org ---
(In reply to janus from comment #5)
> I'm currently not sure which one it is, but I'll investigate.

I think it's both ;)


extends_type_of_3.f90 is definitely wrong, because it contains the exact case
reported in this PR. This fixes it:


Index: gcc/testsuite/gfortran.dg/extends_type_of_3.f90
===
--- gcc/testsuite/gfortran.dg/extends_type_of_3.f90 (Revision 242412)
+++ gcc/testsuite/gfortran.dg/extends_type_of_3.f90 (Arbeitskopie)
@@ -83,7 +83,6 @@
 if (extends_type_of(b1,a1)   .neqv. .true.) call should_not_exist()
 if (extends_type_of(b11,a1)  .neqv. .true.) call should_not_exist()
 if (extends_type_of(b11,a11) .neqv. .true.) call should_not_exist()
-if (extends_type_of(b1,a11)  .neqv. .false.) call should_not_exist()

 if (extends_type_of(a1,b11)  .neqv. .false.) call abort()

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

--- Comment #5 from janus at gcc dot gnu.org ---
(In reply to janus from comment #4)
> The following patch fixes it:

... but unfortunately causes a failure of extends_type_of_3.f90 in the
testsuite, which means either:
* one of the tests in extends_type_of_3.f90 is wrong or
* we're missing an optimization opportunity with my patch.

I'm currently not sure which one it is, but I'll investigate.

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

janus at gcc dot gnu.org changed:

   What|Removed |Added

 Status|NEW |ASSIGNED
   Assignee|unassigned at gcc dot gnu.org  |janus at gcc dot gnu.org

--- Comment #4 from janus at gcc dot gnu.org ---
(In reply to janus from comment #3)
> Confirmed. What's funny is that all eight cases are simplified to
> compile-time constants. That clearly shouldn't be. Probably there's a bug in
> gfc_simplify_extends_type_of.

The regression is due to r168579. The following patch fixes it:

Index: simplify.c
===
--- simplify.c  (Revision 242412)
+++ simplify.c  (Arbeitskopie)
@@ -2531,11 +2531,7 @@
 mold->ts.u.derived->components->ts.u.derived)
  && !gfc_type_is_extension_of
(mold->ts.u.derived->components->ts.u.derived,
-a->ts.u.derived))
-  || (a->ts.type == BT_CLASS && mold->ts.type == BT_DERIVED
- && !gfc_type_is_extension_of
-   (mold->ts.u.derived,
-a->ts.u.derived->components->ts.u.derived)))
+a->ts.u.derived)))
 return gfc_get_logical_expr (gfc_default_logical_kind, >where, false);

   if (mold->ts.type == BT_DERIVED

[Bug fortran/66227] [5/6/7 Regression] [OOP] EXTENDS_TYPE_OF n returns wrong result for polymorphic variable allocated to extended type

[janus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66227

janus at gcc dot gnu.org changed:

   What|Removed |Added

 CC||janus at gcc dot gnu.org
Summary|[OOP] EXTENDS_TYPE_OF n |[5/6/7 Regression] [OOP]
   |returns wrong result for|EXTENDS_TYPE_OF n returns
   |polymorphic variable|wrong result for
   |allocated to extended type  |polymorphic variable
   ||allocated to extended type

--- Comment #3 from janus at gcc dot gnu.org ---
Confirmed. What's funny is that all eight cases are simplified to compile-time
constants. That clearly shouldn't be. Probably there's a bug in
gfc_simplify_extends_type_of.

I think this is a (very old) regression caused by PR 41850: gfortran 4.5 gets
all the values right!