When avoiding double deallocation, look at namespace, expression and component.

Our finalization handling is a mess.  Really, we should get to try and get
this fixed for gcc 11.

In the meantime, here is a patch which fixes a regression I introduced
when fixing a regression with a memory leak.  The important thing
here is to realize that we do not need to finalize (and deallocate)
multiple times for the same expression and the same component
in the same namespace.  It might cause code size regressions, but
better big code than wrong code...

Backported from r11-1296-g1af22e455584ef5fcad2b4474c1efc3fd26f6cb3 .

gcc/fortran/ChangeLog:

	PR fortran/94109
	* class.c (finalize_component): Return early if finalization has
	already happened for expression and component within namespace.
	* gfortran.h (gfc_was_finalized): New type.
	(gfc_namespace): Add member was_finalzed.
	(gfc_expr): Remove finalized.
	* symbol.c (gfc_free_namespace): Free was_finalized.

gcc/testsuite/ChangeLog:

	PR fortran/94109
	* gfortran.dg/finalize_34.f90: Adjust free counts.
	* gfortran.dg/finalize_36.f90: New test.

diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
index 2b55859ce7536f83bcd2299ba8f59bd9530c879f..cfc450283fae942a3365fda64cda78aa40836ec9 100644 (file)
--- a/gcc/fortran/class.c
+++ b/gcc/fortran/class.c
@@ -920,12 +920,18 @@ finalize_component (gfc_expr *expr, gfc_symbol *derived, gfc_component *comp,
 {
   gfc_expr *e;
   gfc_ref *ref;
+  gfc_was_finalized *f;
 
   if (!comp_is_finalizable (comp))
     return;
 
-  if (expr->finalized)
-    return;
+  /* If this expression with this component has been finalized
+     already in this namespace, there is nothing to do.  */
+  for (f = sub_ns->was_finalized; f; f = f->next)
+    {
+      if (f->e == expr && f->c == comp)
+       return;
+    }
 
   e = gfc_copy_expr (expr);
   if (!e->ref)
@@ -1055,7 +1061,13 @@ finalize_component (gfc_expr *expr, gfc_symbol *derived, gfc_component *comp,
                            sub_ns);
       gfc_free_expr (e);
     }
-  expr->finalized = 1;
+
+  /* Record that this was finalized already in this namespace.  */
+  f = sub_ns->was_finalized;
+  sub_ns->was_finalized = XCNEW (gfc_was_finalized);
+  sub_ns->was_finalized->e = expr;
+  sub_ns->was_finalized->c = comp;
+  sub_ns->was_finalized->next = f;
 }
 
 

diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 0ef7b1b0effb182d156eacda29eeeca5f8ced040..d0d51ee78313510accfb8af4a563d9cd101ec3b2 100644 (file)
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -1774,6 +1774,16 @@ gfc_oacc_routine_name;
 
 #define gfc_get_oacc_routine_name() XCNEW (gfc_oacc_routine_name)
 
+/* Node in linked list to see what has already been finalized
+   earlier.  */
+
+typedef struct gfc_was_finalized {
+  gfc_expr *e;
+  gfc_component *c;
+  struct gfc_was_finalized *next;
+}
+gfc_was_finalized;
+
 /* A namespace describes the contents of procedure, module, interface block
    or BLOCK construct.  */
 /* ??? Anything else use these?  */
@@ -1866,6 +1876,11 @@ typedef struct gfc_namespace
   /* Linked list of !$omp declare simd constructs.  */
   struct gfc_omp_declare_simd *omp_declare_simd;
 
+  /* A hash set for the the gfc expressions that have already
+     been finalized in this namespace.  */
+
+  gfc_was_finalized *was_finalized;
+
   /* Set to 1 if namespace is a BLOCK DATA program unit.  */
   unsigned is_block_data:1;
 
@@ -2218,9 +2233,6 @@ 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/fortran/symbol.c b/gcc/fortran/symbol.c
index b96706138c9f4d6ffeabc8441fde7ce344aa2ce2..ba388ff598d3eb2acdb1e8926b9a9c7d8c82064b 100644 (file)
--- a/gcc/fortran/symbol.c
+++ b/gcc/fortran/symbol.c
@@ -4017,6 +4017,7 @@ gfc_free_namespace (gfc_namespace *ns)
 {
   gfc_namespace *p, *q;
   int i;
+  gfc_was_finalized *f;
 
   if (ns == NULL)
     return;
@@ -4049,6 +4050,17 @@ gfc_free_namespace (gfc_namespace *ns)
     gfc_free_interface (ns->op[i]);
 
   gfc_free_data (ns->data);
+
+  /* Free all the expr + component combinations that have been
+     finalized.  */
+  f = ns->was_finalized;
+  while (f)
+    {
+      gfc_was_finalized* current = f;
+      f = f->next;
+      free (current);
+    }
+
   p = ns->contained;
   free (ns);
 

diff --git a/gcc/testsuite/gfortran.dg/finalize_34.f90 b/gcc/testsuite/gfortran.dg/finalize_34.f90
index fef7dac6d89cfde84ef004155ec82fd9153b8918..8fb801d42357a2f117fd96260c804df43ed76221 100644 (file)
--- 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" 12 "original" } }
+! { dg-final  { scan-tree-dump-times "__builtin_free" 24 "original" } }

diff --git a/gcc/testsuite/gfortran.dg/finalize_36.f90 b/gcc/testsuite/gfortran.dg/finalize_36.f90
new file mode 100644 (file)
index 0000000..432f547
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/finalize_36.f90
@@ -0,0 +1,39 @@
+! { dg-do run }
+! { dg-additional-options "-fdump-tree-original" }
+! PR 94109
+! This used to leak memory.  Test case by Antony Lewis.
+    module debug
+    implicit none
+
+    Type Tester
+        real, dimension(:), allocatable :: Dat, Dat2
+    end Type
+
+    Type TestType2
+        Type(Tester) :: T
+    end type TestType2
+
+    contains
+
+    subroutine Leaker
+    class(TestType2), pointer :: ActiveState
+    Type(Tester) :: Temp
+
+    allocate(Temp%Dat2(10000))
+
+    allocate(TestType2::ActiveState)
+    ActiveState%T = Temp
+    deallocate(ActiveState)
+
+    end subroutine
+
+    end module
+
+
+    program run
+    use debug
+
+    call Leaker()
+
+    end program
+! { dg-final { scan-tree-dump-times "__builtin_free\\ \\(ptr2" 4 "original" } }