diff mbox series

[fortran] Fix memory leaks for finalized types

Message ID 7829047f-d7f0-c549-ecaa-666547560f41@netcologne.de
State New
Headers show
Series [fortran] Fix memory leaks for finalized types | expand

Commit Message

Thomas Koenig May 24, 2020, 6:55 p.m. UTC
Hello world,

this patch fixes a 8/9/10/11 regression, where finalized types
were not finalized (and deallocated), which led to memory
leaks.

Once the offending commit was identified (thanks, Harald!) error
analysis was rather straightforward.  The central idea was that
it is the expression that should not be finalized twice, not the
component (which is shared).

Less straightforward was writing a meaningful test case; why I could not
get

! { dg-final  { scan-tree-dump-times "__builtin_free.*dat" 2 "original"
} }

to work (dejagnu always complained about finding it once) I don't know.

Anyway, here is the patch.  I have regression-tested it and made sure
that the size part of PR 87352 did not go up again through the roof.
I have also tested all affected finalize test cases with valgrind and
made sure they are still valid and do not leak.

Once this is in, it will be interesting to see if any other finalizer
bugs are affected.

So, OK for trunk and for backporting to all affected branches?

Regards

	Thomas

Finalization depends on the expression, not on the component.

gcc/fortran/ChangeLog:

2020-05-24  Thomas Koenig  <tkoenig@gcc.gnu.org>

         PR fortran/94361
         * class.c (finalize_component): Use expr->finalized instead of
         comp->finalized.
         * gfortran.h (gfc_component): Remove finalized member.
         (gfc_expr): Add it here instead.

gcc/testsuite/ChangeLog:

2020-05-24  Thomas Koenig  <tkoenig@gcc.gnu.org>

         PR fortran/94361
         * gfortran.dg/finalize_28.f90: Adjusted free counts.
         * gfortran.dg/finalize_33.f90: Likewise.
         * gfortran.dg/finalize_34.f90: Likewise.
         * gfortran.dg/finalize_35.f90: New test..

Comments

Thomas Koenig May 29, 2020, 5:07 p.m. UTC | #1
Am 24.05.20 um 20:55 schrieb Thomas Koenig via Fortran:
> Hello world,
> 
> this patch fixes a 8/9/10/11 regression, where finalized types
> were not finalized (and deallocated), which led to memory
> leaks.

Hi,

OK for trunk? The patch is simple enough (and the regression bad enough)
that I'll commit on Sunday unless there are any objections.

Regards

	Thomas
diff mbox series

Patch

diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
index 9aa3eb7282c..b5a1edae27f 100644
--- a/gcc/fortran/class.c
+++ b/gcc/fortran/class.c
@@ -911,7 +911,7 @@  finalize_component (gfc_expr *expr, gfc_symbol *derived, gfc_component *comp,
   if (!comp_is_finalizable (comp))
     return;
 
-  if (comp->finalized)
+  if (expr->finalized)
     return;
 
   e = gfc_copy_expr (expr);
@@ -1002,6 +1002,7 @@  finalize_component (gfc_expr *expr, gfc_symbol *derived, gfc_component *comp,
 	}
       else
 	(*code) = cond;
+
     }
   else if (comp->ts.type == BT_DERIVED
 	    && comp->ts.u.derived->f2k_derived
@@ -1041,7 +1042,7 @@  finalize_component (gfc_expr *expr, gfc_symbol *derived, gfc_component *comp,
 			    sub_ns);
       gfc_free_expr (e);
     }
-  comp->finalized = true;
+  expr->finalized = 1;
 }
 
 
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 7094791e871..5af44847f9b 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -1107,7 +1107,6 @@  typedef struct gfc_component
   struct gfc_typebound_proc *tb;
   /* When allocatable/pointer and in a coarray the associated token.  */
   tree caf_token;
-  bool finalized;
 }
 gfc_component;
 
@@ -2218,6 +2217,9 @@  typedef struct gfc_expr
   /* Set this if the expression came from expanding an array constructor.  */
   unsigned int from_constructor : 1;
 
+  /* Set this if the expression has already been finalized.  */
+  unsigned int finalized : 1;
+
   /* If an expression comes from a Hollerith constant or compile-time
      evaluation of a transfer statement, it may have a prescribed target-
      memory representation, and these cannot always be backformed from
diff --git a/gcc/testsuite/gfortran.dg/finalize_28.f90 b/gcc/testsuite/gfortran.dg/finalize_28.f90
index 597413b2dd3..f0c9665252f 100644
--- a/gcc/testsuite/gfortran.dg/finalize_28.f90
+++ b/gcc/testsuite/gfortran.dg/finalize_28.f90
@@ -21,4 +21,4 @@  contains
     integer, intent(out) :: edges(:,:)
   end subroutine coo_dump_edges
 end module coo_graphs
-! { dg-final { scan-tree-dump-times "__builtin_free" 5 "original" } }
+! { dg-final { scan-tree-dump-times "__builtin_free" 6 "original" } }
diff --git a/gcc/testsuite/gfortran.dg/finalize_33.f90 b/gcc/testsuite/gfortran.dg/finalize_33.f90
index 2205f9eed7f..3857e4485ee 100644
--- a/gcc/testsuite/gfortran.dg/finalize_33.f90
+++ b/gcc/testsuite/gfortran.dg/finalize_33.f90
@@ -116,4 +116,4 @@  contains
                                                ! (iii) mci_template
 end program main_ut
 ! { dg-final { scan-tree-dump-times "__builtin_malloc" 17 "original" } }
-! { dg-final { scan-tree-dump-times "__builtin_free" 19 "original" } }
+! { dg-final { scan-tree-dump-times "__builtin_free" 20 "original" } }
diff --git a/gcc/testsuite/gfortran.dg/finalize_34.f90 b/gcc/testsuite/gfortran.dg/finalize_34.f90
index e2f02a5c51c..fef7dac6d89 100644
--- a/gcc/testsuite/gfortran.dg/finalize_34.f90
+++ b/gcc/testsuite/gfortran.dg/finalize_34.f90
@@ -22,4 +22,4 @@  program main
   use testmodule
   type(evtlist_type), dimension(10) :: a
 end program main
-! { dg-final  { scan-tree-dump-times "__builtin_free" 8 "original" } }
+! { dg-final  { scan-tree-dump-times "__builtin_free" 12 "original" } }
diff --git a/gcc/testsuite/gfortran.dg/finalize_35.f90 b/gcc/testsuite/gfortran.dg/finalize_35.f90
new file mode 100644
index 00000000000..66435c43ecc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/finalize_35.f90
@@ -0,0 +1,48 @@ 
+! { dg-do compile }
+! { dg-additional-options "-fdump-tree-original" }
+! PR 94361 - this left open some memory leaks.  Original test case by
+! Antony Lewis.
+
+module debug
+  private
+
+  Type TypeWithFinal
+   contains
+     FINAL :: finalizer  !No leak if this line is commented
+  end type TypeWithFinal
+
+  Type Tester
+     real, dimension(:), allocatable :: Dat
+     Type(TypeWithFinal) :: X
+  end Type Tester
+
+  Type :: TestType2
+     Type(Tester) :: T
+  end type TestType2
+  public Leaker
+contains
+
+  subroutine Leaker
+    type(TestType2) :: Test
+
+    allocate(Test%T%Dat(1000))
+  end subroutine Leaker
+
+  subroutine finalizer(this)
+    Type(TypeWithFinal) :: this
+  end subroutine finalizer
+
+end module debug
+
+
+program run
+  use debug
+  implicit none
+  integer i
+
+  do i=1, 1000
+     call Leaker()
+  end do
+
+end program run
+! { dg-final  { scan-tree-dump-times "__builtin_free\\ \\(ptr2" 2 "original" } }