[Patch, Fortran, OOP] PR 64230: [4.9/5 Regression] Invalid memory reference in a compiler-generated finalizer for allocatable component

[Janus Weil <janus at gcc dot gnu dot org>]

Hi,

this is a second patch dealing with finalization-related regressions,
after the one I submitted yesterday
(https://gcc.gnu.org/ml/fortran/2015-01/msg00109.html), which btw is
also still waiting for review ...

This patch fixes an invalid memory reference inside the finalizer
routine (at runtime), which apparently was caused by dereferencing a
pointer without checking if it's NULL. I simply insert a call to
ASSOCIATED.

I also rename two different runtime variables, which were both called
'ptr', to 'ptr1' and 'ptr2', just to make it easier to distinguish
them in the dump.

I also have the feeling the a lot of what is being done in
generate_finalization_wrapper and finalize_component (including my
changes) is a bit laborious. Some helper functions might be useful to
make all that code generation a bit more readable and less verbose. I
may attack this in a follow-up patch.

This one regtests cleanly on x86_64-unknown-linux-gnu. Ok for trunk and 4.9?

Cheers,
Janus



2015-01-19  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/64230
    * class.c (finalize_component): New argument 'sub_ns'. Insert code to
    check if 'expr' is associated.
    (generate_finalization_wrapper): Rename 'ptr' symbols to 'ptr1' and
    'ptr2'. Pass 'sub_ns' to finalize_component.

2015-01-19  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/64230
    * gfortran.dg/class_allocate_18.f90: Extended.

Attachment: pr64230.diff
Description: Text document

! { dg-do run }
! { dg-options "-fsanitize=undefined" }
!
! PR 64230: [4.9/5 Regression] Invalid memory reference in a compiler-generated finalizer for allocatable component
!
! Contributed by Mat Cross <mathewc@nag.co.uk>

Program main
  Implicit None
  Type :: t1
  End Type
  Type, Extends (t1) :: t2
    Integer, Allocatable :: i
  End Type
  Type, Extends (t2) :: t3
    Integer, Allocatable :: j
  End Type
  Class (t1), Allocatable :: t
  Allocate (t3 :: t)
  print *,"allocated!"
  Deallocate (t)
End