diff mbox series

[FORTRAN] Fix memory leak in finalization wrappers

Message ID 20181015082306.23083-1-rep.dot.nop@gmail.com
State New
Headers show
Series [FORTRAN] Fix memory leak in finalization wrappers | expand

Commit Message

Bernhard Reutner-Fischer Oct. 15, 2018, 8:23 a.m. UTC
If a finalization is not required we created a namespace containing
formal arguments for an internal interface definition but never used
any of these. So the whole sub_ns namespace was not wired up to the
program and consequently was never freed. The fix is to simply not
generate any finalization wrappers if we know that it will be unused.
Note that this reverts back to the original r190869
(8a96d64282ac534cb597f446f02ac5d0b13249cc) handling for this case
by reverting this specific part of r194075
(f1ee56b4be7cc3892e6ccc75d73033c129098e87) for PR fortran/37336.

Regtests cleanly, installed to the fortran-fe-stringpool branch, sent
here for reference and later inclusion.
I might plug a few more leaks in preparation of switching to hash-maps.
I fear that the leaks around interfaces are another candidate ;)

Should probably add a tag for the compile-time leak PR68800 shouldn't i.

valgrind summary for e.g.
gfortran.dg/abstract_type_3.f03 and gfortran.dg/abstract_type_4.f03
where ".orig" is pristine trunk and ".mine" contains this fix:

at3.orig.vg:LEAK SUMMARY:
at3.orig.vg-   definitely lost: 8,460 bytes in 11 blocks
at3.orig.vg-   indirectly lost: 13,288 bytes in 55 blocks
at3.orig.vg-     possibly lost: 0 bytes in 0 blocks
at3.orig.vg-   still reachable: 572,278 bytes in 2,142 blocks
at3.orig.vg-        suppressed: 0 bytes in 0 blocks
at3.orig.vg-
at3.orig.vg-Use --track-origins=yes to see where uninitialised values come from
at3.orig.vg-ERROR SUMMARY: 38 errors from 33 contexts (suppressed: 0 from 0)
--
at3.mine.vg:LEAK SUMMARY:
at3.mine.vg-   definitely lost: 344 bytes in 1 blocks
at3.mine.vg-   indirectly lost: 7,192 bytes in 18 blocks
at3.mine.vg-     possibly lost: 0 bytes in 0 blocks
at3.mine.vg-   still reachable: 572,278 bytes in 2,142 blocks
at3.mine.vg-        suppressed: 0 bytes in 0 blocks
at3.mine.vg-
at3.mine.vg-ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
at3.mine.vg-ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
at4.orig.vg:LEAK SUMMARY:
at4.orig.vg-   definitely lost: 13,751 bytes in 12 blocks
at4.orig.vg-   indirectly lost: 11,976 bytes in 60 blocks
at4.orig.vg-     possibly lost: 0 bytes in 0 blocks
at4.orig.vg-   still reachable: 572,278 bytes in 2,142 blocks
at4.orig.vg-        suppressed: 0 bytes in 0 blocks
at4.orig.vg-
at4.orig.vg-Use --track-origins=yes to see where uninitialised values come from
at4.orig.vg-ERROR SUMMARY: 18 errors from 16 contexts (suppressed: 0 from 0)
--
at4.mine.vg:LEAK SUMMARY:
at4.mine.vg-   definitely lost: 3,008 bytes in 3 blocks
at4.mine.vg-   indirectly lost: 4,056 bytes in 11 blocks
at4.mine.vg-     possibly lost: 0 bytes in 0 blocks
at4.mine.vg-   still reachable: 572,278 bytes in 2,142 blocks
at4.mine.vg-        suppressed: 0 bytes in 0 blocks
at4.mine.vg-
at4.mine.vg-ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)
at4.mine.vg-ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)

gcc/fortran/ChangeLog:

2018-10-12  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>

	* class.c (generate_finalization_wrapper): Do leak finalization
	wrappers if they will not be used.
	* expr.c (gfc_free_actual_arglist): Formatting fix.
	* gfortran.h (gfc_free_symbol): Pass argument by reference.
	(gfc_release_symbol): Likewise.
	(gfc_free_namespace): Likewise.
	* symbol.c (gfc_release_symbol): Adjust acordingly.
	(free_components): Set procedure pointer components
	of derived types to NULL after freeing.
	(free_tb_tree): Likewise.
	(gfc_free_symbol): Set sym to NULL after freeing.
	(gfc_free_namespace): Set namespace to NULL after freeing.
---
 gcc/fortran/class.c    | 25 +++++++++----------------
 gcc/fortran/expr.c     |  2 +-
 gcc/fortran/gfortran.h |  6 +++---
 gcc/fortran/symbol.c   | 19 ++++++++++---------
 4 files changed, 23 insertions(+), 29 deletions(-)

Comments

Bernhard Reutner-Fischer Oct. 27, 2021, 9:39 p.m. UTC | #1
Ping
[hmz. it's been a while, I'll rebase and retest this one.
Ok if it passes?]

On Mon, 15 Oct 2018 10:23:06 +0200
Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:

> If a finalization is not required we created a namespace containing
> formal arguments for an internal interface definition but never used
> any of these. So the whole sub_ns namespace was not wired up to the
> program and consequently was never freed. The fix is to simply not
> generate any finalization wrappers if we know that it will be unused.
> Note that this reverts back to the original r190869
> (8a96d64282ac534cb597f446f02ac5d0b13249cc) handling for this case
> by reverting this specific part of r194075
> (f1ee56b4be7cc3892e6ccc75d73033c129098e87) for PR fortran/37336.
> 
> Regtests cleanly, installed to the fortran-fe-stringpool branch, sent
> here for reference and later inclusion.
> I might plug a few more leaks in preparation of switching to hash-maps.
> I fear that the leaks around interfaces are another candidate ;)
> 
> Should probably add a tag for the compile-time leak PR68800 shouldn't i.
> 
> valgrind summary for e.g.
> gfortran.dg/abstract_type_3.f03 and gfortran.dg/abstract_type_4.f03
> where ".orig" is pristine trunk and ".mine" contains this fix:
> 
> at3.orig.vg:LEAK SUMMARY:
> at3.orig.vg-   definitely lost: 8,460 bytes in 11 blocks
> at3.orig.vg-   indirectly lost: 13,288 bytes in 55 blocks
> at3.orig.vg-     possibly lost: 0 bytes in 0 blocks
> at3.orig.vg-   still reachable: 572,278 bytes in 2,142 blocks
> at3.orig.vg-        suppressed: 0 bytes in 0 blocks
> at3.orig.vg-
> at3.orig.vg-Use --track-origins=yes to see where uninitialised values come from
> at3.orig.vg-ERROR SUMMARY: 38 errors from 33 contexts (suppressed: 0 from 0)
> --
> at3.mine.vg:LEAK SUMMARY:
> at3.mine.vg-   definitely lost: 344 bytes in 1 blocks
> at3.mine.vg-   indirectly lost: 7,192 bytes in 18 blocks
> at3.mine.vg-     possibly lost: 0 bytes in 0 blocks
> at3.mine.vg-   still reachable: 572,278 bytes in 2,142 blocks
> at3.mine.vg-        suppressed: 0 bytes in 0 blocks
> at3.mine.vg-
> at3.mine.vg-ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
> at3.mine.vg-ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
> at4.orig.vg:LEAK SUMMARY:
> at4.orig.vg-   definitely lost: 13,751 bytes in 12 blocks
> at4.orig.vg-   indirectly lost: 11,976 bytes in 60 blocks
> at4.orig.vg-     possibly lost: 0 bytes in 0 blocks
> at4.orig.vg-   still reachable: 572,278 bytes in 2,142 blocks
> at4.orig.vg-        suppressed: 0 bytes in 0 blocks
> at4.orig.vg-
> at4.orig.vg-Use --track-origins=yes to see where uninitialised values come from
> at4.orig.vg-ERROR SUMMARY: 18 errors from 16 contexts (suppressed: 0 from 0)
> --
> at4.mine.vg:LEAK SUMMARY:
> at4.mine.vg-   definitely lost: 3,008 bytes in 3 blocks
> at4.mine.vg-   indirectly lost: 4,056 bytes in 11 blocks
> at4.mine.vg-     possibly lost: 0 bytes in 0 blocks
> at4.mine.vg-   still reachable: 572,278 bytes in 2,142 blocks
> at4.mine.vg-        suppressed: 0 bytes in 0 blocks
> at4.mine.vg-
> at4.mine.vg-ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)
> at4.mine.vg-ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)
> 
> gcc/fortran/ChangeLog:
> 
> 2018-10-12  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>
> 
> 	* class.c (generate_finalization_wrapper): Do leak finalization
> 	wrappers if they will not be used.
> 	* expr.c (gfc_free_actual_arglist): Formatting fix.
> 	* gfortran.h (gfc_free_symbol): Pass argument by reference.
> 	(gfc_release_symbol): Likewise.
> 	(gfc_free_namespace): Likewise.
> 	* symbol.c (gfc_release_symbol): Adjust acordingly.
> 	(free_components): Set procedure pointer components
> 	of derived types to NULL after freeing.
> 	(free_tb_tree): Likewise.
> 	(gfc_free_symbol): Set sym to NULL after freeing.
> 	(gfc_free_namespace): Set namespace to NULL after freeing.
> ---
>  gcc/fortran/class.c    | 25 +++++++++----------------
>  gcc/fortran/expr.c     |  2 +-
>  gcc/fortran/gfortran.h |  6 +++---
>  gcc/fortran/symbol.c   | 19 ++++++++++---------
>  4 files changed, 23 insertions(+), 29 deletions(-)
> 
> diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
> index 69c95fc5dfa..e0bb381a55f 100644
> --- a/gcc/fortran/class.c
> +++ b/gcc/fortran/class.c
> @@ -1533,7 +1533,6 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
>    gfc_code *last_code, *block;
>    const char *name;
>    bool finalizable_comp = false;
> -  bool expr_null_wrapper = false;
>    gfc_expr *ancestor_wrapper = NULL, *rank;
>    gfc_iterator *iter;
>  
> @@ -1561,13 +1560,17 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
>      }
>  
>    /* No wrapper of the ancestor and no own FINAL subroutines and allocatable
> -     components: Return a NULL() expression; we defer this a bit to have have
> +     components: Return a NULL() expression; we defer this a bit to have
>       an interface declaration.  */
>    if ((!ancestor_wrapper || ancestor_wrapper->expr_type == EXPR_NULL)
>        && !derived->attr.alloc_comp
>        && (!derived->f2k_derived || !derived->f2k_derived->finalizers)
>        && !has_finalizer_component (derived))
> -    expr_null_wrapper = true;
> +    {
> +      vtab_final->initializer = gfc_get_null_expr (NULL);
> +      gcc_assert (vtab_final->ts.interface == NULL);
> +      return;
> +    }
>    else
>      /* Check whether there are new allocatable components.  */
>      for (comp = derived->components; comp; comp = comp->next)
> @@ -1581,7 +1584,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
>  
>    /* If there is no new finalizer and no new allocatable, return with
>       an expr to the ancestor's one.  */
> -  if (!expr_null_wrapper && !finalizable_comp
> +  if (!finalizable_comp
>        && (!derived->f2k_derived || !derived->f2k_derived->finalizers))
>      {
>        gcc_assert (ancestor_wrapper && ancestor_wrapper->ref == NULL
> @@ -1605,8 +1608,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
>    /* Set up the namespace.  */
>    sub_ns = gfc_get_namespace (ns, 0);
>    sub_ns->sibling = ns->contained;
> -  if (!expr_null_wrapper)
> -    ns->contained = sub_ns;
> +  ns->contained = sub_ns;
>    sub_ns->resolved = 1;
>  
>    /* Set up the procedure symbol.  */
> @@ -1622,7 +1624,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
>    final->ts.kind = 4;
>    final->attr.artificial = 1;
>    final->attr.always_explicit = 1;
> -  final->attr.if_source = expr_null_wrapper ? IFSRC_IFBODY : IFSRC_DECL;
> +  final->attr.if_source = IFSRC_DECL;
>    if (ns->proc_name->attr.flavor == FL_MODULE)
>      final->module = ns->proc_name->name;
>    gfc_set_sym_referenced (final);
> @@ -1672,15 +1674,6 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
>    final->formal->next->next->sym = fini_coarray;
>    gfc_commit_symbol (fini_coarray);
>  
> -  /* Return with a NULL() expression but with an interface which has
> -     the formal arguments.  */
> -  if (expr_null_wrapper)
> -    {
> -      vtab_final->initializer = gfc_get_null_expr (NULL);
> -      vtab_final->ts.interface = final;
> -      return;
> -    }
> -
>    /* Local variables.  */
>  
>    gfc_get_symbol (gfc_get_string ("%s", "idx"), sub_ns, &idx);
> diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
> index cc12e0a8402..3d744ec9641 100644
> --- a/gcc/fortran/expr.c
> +++ b/gcc/fortran/expr.c
> @@ -533,7 +533,7 @@ gfc_free_actual_arglist (gfc_actual_arglist *a1)
>      {
>        a2 = a1->next;
>        if (a1->expr)
> -      gfc_free_expr (a1->expr);
> +	gfc_free_expr (a1->expr);
>        free (a1);
>        a1 = a2;
>      }
> diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
> index 4612835706b..3466c42132f 100644
> --- a/gcc/fortran/gfortran.h
> +++ b/gcc/fortran/gfortran.h
> @@ -3032,8 +3032,8 @@ gfc_user_op *gfc_get_uop (const char *);
>  gfc_user_op *gfc_find_uop (const char *, gfc_namespace *);
>  const char *gfc_get_uop_from_name (const char*);
>  const char *gfc_get_name_from_uop (const char*);
> -void gfc_free_symbol (gfc_symbol *);
> -void gfc_release_symbol (gfc_symbol *);
> +void gfc_free_symbol (gfc_symbol *&);
> +void gfc_release_symbol (gfc_symbol *&);
>  gfc_symbol *gfc_new_symbol (const char *, gfc_namespace *);
>  gfc_symtree* gfc_find_symtree_in_proc (const char *, gfc_namespace *);
>  int gfc_find_symbol (const char *, gfc_namespace *, int, gfc_symbol **);
> @@ -3058,7 +3058,7 @@ void gfc_commit_symbols (void);
>  void gfc_commit_symbol (gfc_symbol *);
>  gfc_charlen *gfc_new_charlen (gfc_namespace *, gfc_charlen *);
>  void gfc_free_charlen (gfc_charlen *, gfc_charlen *);
> -void gfc_free_namespace (gfc_namespace *);
> +void gfc_free_namespace (gfc_namespace *&);
>  
>  void gfc_symbol_init_2 (void);
>  void gfc_symbol_done_2 (void);
> diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c
> index 09ad2bbf0cd..c99c106a0c0 100644
> --- a/gcc/fortran/symbol.c
> +++ b/gcc/fortran/symbol.c
> @@ -2590,8 +2590,9 @@ free_components (gfc_component *p)
>  	gfc_free_expr (p->kind_expr);
>        if (p->param_list)
>  	gfc_free_actual_arglist (p->param_list);
> -      free (p->tb);
>  
> +      free (p->tb);
> +      p->tb = NULL;
>        free (p);
>      }
>  }
> @@ -3070,7 +3071,7 @@ set_symbol_common_block (gfc_symbol *sym, gfc_common_head *common_block)
>  /* Remove a gfc_symbol structure and everything it points to.  */
>  
>  void
> -gfc_free_symbol (gfc_symbol *sym)
> +gfc_free_symbol (gfc_symbol *&sym)
>  {
>  
>    if (sym == NULL)
> @@ -3078,8 +3079,6 @@ gfc_free_symbol (gfc_symbol *sym)
>  
>    gfc_free_array_spec (sym->as);
>  
> -  free_components (sym->components);
> -
>    gfc_free_expr (sym->value);
>  
>    gfc_free_namelist (sym->namelist);
> @@ -3094,19 +3093,22 @@ gfc_free_symbol (gfc_symbol *sym)
>  
>    gfc_free_namespace (sym->f2k_derived);
>  
> +  free_components (sym->components);
> +
>    set_symbol_common_block (sym, NULL);
>  
>    if (sym->param_list)
>      gfc_free_actual_arglist (sym->param_list);
>  
>    free (sym);
> +  sym = NULL;
>  }
>  
>  
>  /* Decrease the reference counter and free memory when we reach zero.  */
>  
>  void
> -gfc_release_symbol (gfc_symbol *sym)
> +gfc_release_symbol (gfc_symbol *&sym)
>  {
>    if (sym == NULL)
>      return;
> @@ -3826,10 +3828,8 @@ free_tb_tree (gfc_symtree *t)
>  
>    free_tb_tree (t->left);
>    free_tb_tree (t->right);
> -
> -  /* TODO: Free type-bound procedure structs themselves; probably needs some
> -     sort of ref-counting mechanism.  */
>    free (t->n.tb);
> +  t->n.tb = NULL;
>    free (t);
>  }
>  
> @@ -4019,7 +4019,7 @@ free_entry_list (gfc_entry_list *el)
>     taken care of when a specific name is freed.  */
>  
>  void
> -gfc_free_namespace (gfc_namespace *ns)
> +gfc_free_namespace (gfc_namespace *&ns)
>  {
>    gfc_namespace *p, *q;
>    int i;
> @@ -4057,6 +4057,7 @@ gfc_free_namespace (gfc_namespace *ns)
>    gfc_free_data (ns->data);
>    p = ns->contained;
>    free (ns);
> +  ns = NULL;
>  
>    /* Recursively free any contained namespaces.  */
>    while (p != NULL)
Bernhard Reutner-Fischer Oct. 28, 2021, 11:58 p.m. UTC | #2
On Wed, 27 Oct 2021 23:39:43 +0200
Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:

> Ping
> [hmz. it's been a while, I'll rebase and retest this one.
> Ok if it passes?]
Testing passed without any new regressions.
Ok for trunk?
thanks,
> 
> On Mon, 15 Oct 2018 10:23:06 +0200
> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
> 
> > If a finalization is not required we created a namespace containing
> > formal arguments for an internal interface definition but never used
> > any of these. So the whole sub_ns namespace was not wired up to the
> > program and consequently was never freed. The fix is to simply not
> > generate any finalization wrappers if we know that it will be unused.
> > Note that this reverts back to the original r190869
> > (8a96d64282ac534cb597f446f02ac5d0b13249cc) handling for this case
> > by reverting this specific part of r194075
> > (f1ee56b4be7cc3892e6ccc75d73033c129098e87) for PR fortran/37336.
> > 
> > Regtests cleanly, installed to the fortran-fe-stringpool branch, sent
> > here for reference and later inclusion.
> > I might plug a few more leaks in preparation of switching to hash-maps.
> > I fear that the leaks around interfaces are another candidate ;)
> > 
> > Should probably add a tag for the compile-time leak PR68800 shouldn't i.
> > 
> > valgrind summary for e.g.
> > gfortran.dg/abstract_type_3.f03 and gfortran.dg/abstract_type_4.f03
> > where ".orig" is pristine trunk and ".mine" contains this fix:
> > 
> > at3.orig.vg:LEAK SUMMARY:
> > at3.orig.vg-   definitely lost: 8,460 bytes in 11 blocks
> > at3.orig.vg-   indirectly lost: 13,288 bytes in 55 blocks
> > at3.orig.vg-     possibly lost: 0 bytes in 0 blocks
> > at3.orig.vg-   still reachable: 572,278 bytes in 2,142 blocks
> > at3.orig.vg-        suppressed: 0 bytes in 0 blocks
> > at3.orig.vg-
> > at3.orig.vg-Use --track-origins=yes to see where uninitialised values come from
> > at3.orig.vg-ERROR SUMMARY: 38 errors from 33 contexts (suppressed: 0 from 0)
> > --
> > at3.mine.vg:LEAK SUMMARY:
> > at3.mine.vg-   definitely lost: 344 bytes in 1 blocks
> > at3.mine.vg-   indirectly lost: 7,192 bytes in 18 blocks
> > at3.mine.vg-     possibly lost: 0 bytes in 0 blocks
> > at3.mine.vg-   still reachable: 572,278 bytes in 2,142 blocks
> > at3.mine.vg-        suppressed: 0 bytes in 0 blocks
> > at3.mine.vg-
> > at3.mine.vg-ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
> > at3.mine.vg-ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
> > at4.orig.vg:LEAK SUMMARY:
> > at4.orig.vg-   definitely lost: 13,751 bytes in 12 blocks
> > at4.orig.vg-   indirectly lost: 11,976 bytes in 60 blocks
> > at4.orig.vg-     possibly lost: 0 bytes in 0 blocks
> > at4.orig.vg-   still reachable: 572,278 bytes in 2,142 blocks
> > at4.orig.vg-        suppressed: 0 bytes in 0 blocks
> > at4.orig.vg-
> > at4.orig.vg-Use --track-origins=yes to see where uninitialised values come from
> > at4.orig.vg-ERROR SUMMARY: 18 errors from 16 contexts (suppressed: 0 from 0)
> > --
> > at4.mine.vg:LEAK SUMMARY:
> > at4.mine.vg-   definitely lost: 3,008 bytes in 3 blocks
> > at4.mine.vg-   indirectly lost: 4,056 bytes in 11 blocks
> > at4.mine.vg-     possibly lost: 0 bytes in 0 blocks
> > at4.mine.vg-   still reachable: 572,278 bytes in 2,142 blocks
> > at4.mine.vg-        suppressed: 0 bytes in 0 blocks
> > at4.mine.vg-
> > at4.mine.vg-ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)
> > at4.mine.vg-ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)
> > 
> > gcc/fortran/ChangeLog:
> > 
> > 2018-10-12  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>
> > 
> > 	* class.c (generate_finalization_wrapper): Do leak finalization
> > 	wrappers if they will not be used.
> > 	* expr.c (gfc_free_actual_arglist): Formatting fix.
> > 	* gfortran.h (gfc_free_symbol): Pass argument by reference.
> > 	(gfc_release_symbol): Likewise.
> > 	(gfc_free_namespace): Likewise.
> > 	* symbol.c (gfc_release_symbol): Adjust acordingly.
> > 	(free_components): Set procedure pointer components
> > 	of derived types to NULL after freeing.
> > 	(free_tb_tree): Likewise.
> > 	(gfc_free_symbol): Set sym to NULL after freeing.
> > 	(gfc_free_namespace): Set namespace to NULL after freeing.
> > ---
> >  gcc/fortran/class.c    | 25 +++++++++----------------
> >  gcc/fortran/expr.c     |  2 +-
> >  gcc/fortran/gfortran.h |  6 +++---
> >  gcc/fortran/symbol.c   | 19 ++++++++++---------
> >  4 files changed, 23 insertions(+), 29 deletions(-)
> > 
> > diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
> > index 69c95fc5dfa..e0bb381a55f 100644
> > --- a/gcc/fortran/class.c
> > +++ b/gcc/fortran/class.c
> > @@ -1533,7 +1533,6 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
> >    gfc_code *last_code, *block;
> >    const char *name;
> >    bool finalizable_comp = false;
> > -  bool expr_null_wrapper = false;
> >    gfc_expr *ancestor_wrapper = NULL, *rank;
> >    gfc_iterator *iter;
> >  
> > @@ -1561,13 +1560,17 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
> >      }
> >  
> >    /* No wrapper of the ancestor and no own FINAL subroutines and allocatable
> > -     components: Return a NULL() expression; we defer this a bit to have have
> > +     components: Return a NULL() expression; we defer this a bit to have
> >       an interface declaration.  */
> >    if ((!ancestor_wrapper || ancestor_wrapper->expr_type == EXPR_NULL)
> >        && !derived->attr.alloc_comp
> >        && (!derived->f2k_derived || !derived->f2k_derived->finalizers)
> >        && !has_finalizer_component (derived))
> > -    expr_null_wrapper = true;
> > +    {
> > +      vtab_final->initializer = gfc_get_null_expr (NULL);
> > +      gcc_assert (vtab_final->ts.interface == NULL);
> > +      return;
> > +    }
> >    else
> >      /* Check whether there are new allocatable components.  */
> >      for (comp = derived->components; comp; comp = comp->next)
> > @@ -1581,7 +1584,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
> >  
> >    /* If there is no new finalizer and no new allocatable, return with
> >       an expr to the ancestor's one.  */
> > -  if (!expr_null_wrapper && !finalizable_comp
> > +  if (!finalizable_comp
> >        && (!derived->f2k_derived || !derived->f2k_derived->finalizers))
> >      {
> >        gcc_assert (ancestor_wrapper && ancestor_wrapper->ref == NULL
> > @@ -1605,8 +1608,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
> >    /* Set up the namespace.  */
> >    sub_ns = gfc_get_namespace (ns, 0);
> >    sub_ns->sibling = ns->contained;
> > -  if (!expr_null_wrapper)
> > -    ns->contained = sub_ns;
> > +  ns->contained = sub_ns;
> >    sub_ns->resolved = 1;
> >  
> >    /* Set up the procedure symbol.  */
> > @@ -1622,7 +1624,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
> >    final->ts.kind = 4;
> >    final->attr.artificial = 1;
> >    final->attr.always_explicit = 1;
> > -  final->attr.if_source = expr_null_wrapper ? IFSRC_IFBODY : IFSRC_DECL;
> > +  final->attr.if_source = IFSRC_DECL;
> >    if (ns->proc_name->attr.flavor == FL_MODULE)
> >      final->module = ns->proc_name->name;
> >    gfc_set_sym_referenced (final);
> > @@ -1672,15 +1674,6 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
> >    final->formal->next->next->sym = fini_coarray;
> >    gfc_commit_symbol (fini_coarray);
> >  
> > -  /* Return with a NULL() expression but with an interface which has
> > -     the formal arguments.  */
> > -  if (expr_null_wrapper)
> > -    {
> > -      vtab_final->initializer = gfc_get_null_expr (NULL);
> > -      vtab_final->ts.interface = final;
> > -      return;
> > -    }
> > -
> >    /* Local variables.  */
> >  
> >    gfc_get_symbol (gfc_get_string ("%s", "idx"), sub_ns, &idx);
> > diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
> > index cc12e0a8402..3d744ec9641 100644
> > --- a/gcc/fortran/expr.c
> > +++ b/gcc/fortran/expr.c
> > @@ -533,7 +533,7 @@ gfc_free_actual_arglist (gfc_actual_arglist *a1)
> >      {
> >        a2 = a1->next;
> >        if (a1->expr)
> > -      gfc_free_expr (a1->expr);
> > +	gfc_free_expr (a1->expr);
> >        free (a1);
> >        a1 = a2;
> >      }
> > diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
> > index 4612835706b..3466c42132f 100644
> > --- a/gcc/fortran/gfortran.h
> > +++ b/gcc/fortran/gfortran.h
> > @@ -3032,8 +3032,8 @@ gfc_user_op *gfc_get_uop (const char *);
> >  gfc_user_op *gfc_find_uop (const char *, gfc_namespace *);
> >  const char *gfc_get_uop_from_name (const char*);
> >  const char *gfc_get_name_from_uop (const char*);
> > -void gfc_free_symbol (gfc_symbol *);
> > -void gfc_release_symbol (gfc_symbol *);
> > +void gfc_free_symbol (gfc_symbol *&);
> > +void gfc_release_symbol (gfc_symbol *&);
> >  gfc_symbol *gfc_new_symbol (const char *, gfc_namespace *);
> >  gfc_symtree* gfc_find_symtree_in_proc (const char *, gfc_namespace *);
> >  int gfc_find_symbol (const char *, gfc_namespace *, int, gfc_symbol **);
> > @@ -3058,7 +3058,7 @@ void gfc_commit_symbols (void);
> >  void gfc_commit_symbol (gfc_symbol *);
> >  gfc_charlen *gfc_new_charlen (gfc_namespace *, gfc_charlen *);
> >  void gfc_free_charlen (gfc_charlen *, gfc_charlen *);
> > -void gfc_free_namespace (gfc_namespace *);
> > +void gfc_free_namespace (gfc_namespace *&);
> >  
> >  void gfc_symbol_init_2 (void);
> >  void gfc_symbol_done_2 (void);
> > diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c
> > index 09ad2bbf0cd..c99c106a0c0 100644
> > --- a/gcc/fortran/symbol.c
> > +++ b/gcc/fortran/symbol.c
> > @@ -2590,8 +2590,9 @@ free_components (gfc_component *p)
> >  	gfc_free_expr (p->kind_expr);
> >        if (p->param_list)
> >  	gfc_free_actual_arglist (p->param_list);
> > -      free (p->tb);
> >  
> > +      free (p->tb);
> > +      p->tb = NULL;
> >        free (p);
> >      }
> >  }
> > @@ -3070,7 +3071,7 @@ set_symbol_common_block (gfc_symbol *sym, gfc_common_head *common_block)
> >  /* Remove a gfc_symbol structure and everything it points to.  */
> >  
> >  void
> > -gfc_free_symbol (gfc_symbol *sym)
> > +gfc_free_symbol (gfc_symbol *&sym)
> >  {
> >  
> >    if (sym == NULL)
> > @@ -3078,8 +3079,6 @@ gfc_free_symbol (gfc_symbol *sym)
> >  
> >    gfc_free_array_spec (sym->as);
> >  
> > -  free_components (sym->components);
> > -
> >    gfc_free_expr (sym->value);
> >  
> >    gfc_free_namelist (sym->namelist);
> > @@ -3094,19 +3093,22 @@ gfc_free_symbol (gfc_symbol *sym)
> >  
> >    gfc_free_namespace (sym->f2k_derived);
> >  
> > +  free_components (sym->components);
> > +
> >    set_symbol_common_block (sym, NULL);
> >  
> >    if (sym->param_list)
> >      gfc_free_actual_arglist (sym->param_list);
> >  
> >    free (sym);
> > +  sym = NULL;
> >  }
> >  
> >  
> >  /* Decrease the reference counter and free memory when we reach zero.  */
> >  
> >  void
> > -gfc_release_symbol (gfc_symbol *sym)
> > +gfc_release_symbol (gfc_symbol *&sym)
> >  {
> >    if (sym == NULL)
> >      return;
> > @@ -3826,10 +3828,8 @@ free_tb_tree (gfc_symtree *t)
> >  
> >    free_tb_tree (t->left);
> >    free_tb_tree (t->right);
> > -
> > -  /* TODO: Free type-bound procedure structs themselves; probably needs some
> > -     sort of ref-counting mechanism.  */
> >    free (t->n.tb);
> > +  t->n.tb = NULL;
> >    free (t);
> >  }
> >  
> > @@ -4019,7 +4019,7 @@ free_entry_list (gfc_entry_list *el)
> >     taken care of when a specific name is freed.  */
> >  
> >  void
> > -gfc_free_namespace (gfc_namespace *ns)
> > +gfc_free_namespace (gfc_namespace *&ns)
> >  {
> >    gfc_namespace *p, *q;
> >    int i;
> > @@ -4057,6 +4057,7 @@ gfc_free_namespace (gfc_namespace *ns)
> >    gfc_free_data (ns->data);
> >    p = ns->contained;
> >    free (ns);
> > +  ns = NULL;
> >  
> >    /* Recursively free any contained namespaces.  */
> >    while (p != NULL)  
>
Mikael Morin Nov. 5, 2021, 6:46 p.m. UTC | #3
Le 29/10/2021 à 01:58, Bernhard Reutner-Fischer via Fortran a écrit :
> On Wed, 27 Oct 2021 23:39:43 +0200
> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
> 
>> Ping
>> [hmz. it's been a while, I'll rebase and retest this one.
>> Ok if it passes?]
> Testing passed without any new regressions.
> Ok for trunk?
> thanks,
>>
>> On Mon, 15 Oct 2018 10:23:06 +0200
>> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
>>
>>> If a finalization is not required we created a namespace containing
>>> formal arguments for an internal interface definition but never used
>>> any of these. So the whole sub_ns namespace was not wired up to the
>>> program and consequently was never freed. The fix is to simply not
>>> generate any finalization wrappers if we know that it will be unused.
>>> Note that this reverts back to the original r190869
>>> (8a96d64282ac534cb597f446f02ac5d0b13249cc) handling for this case
>>> by reverting this specific part of r194075
>>> (f1ee56b4be7cc3892e6ccc75d73033c129098e87) for PR fortran/37336.
>>>
I’m a bit concerned by the loss of the null_expr’s type interface.
I can’t convince myself that it’s either absolutely necessary or 
completely useless.
Tobias didn’t include a test in his commit unfortunately, but I bet he 
did the change on purpose.
Don’t you get the same effect on the memory leaks if you keep just the 
following hunk?

 >>> @@ -1605,8 +1608,7 @@ generate_finalization_wrapper (gfc_symbol 
*derived, gfc_namespace *ns,
 >>>     /* Set up the namespace.  */
 >>>     sub_ns = gfc_get_namespace (ns, 0);
 >>>     sub_ns->sibling = ns->contained;
 >>> -  if (!expr_null_wrapper)
 >>> -    ns->contained = sub_ns;
 >>> +  ns->contained = sub_ns;
 >>>     sub_ns->resolved = 1;
 >>>
 >>>     /* Set up the procedure symbol.  */


The rest of the changes (appart from class.c) are mostly OK with the nit 
below and should be put in their own commit.

 >>> @@ -3826,10 +3828,8 @@ free_tb_tree (gfc_symtree *t)
 >>>
 >>>     free_tb_tree (t->left);
 >>>     free_tb_tree (t->right);
 >>> -
 >>> -  /* TODO: Free type-bound procedure structs themselves; probably 
needs some
 >>> -     sort of ref-counting mechanism.  */
 >>>     free (t->n.tb);

Please keep a comment; it remains somehow valid but could be updated 
maybe: gfc_typebound_proc’s u.generic field for example is nowhere freed 
as far as I know.

Thanks.

Mikael
Bernhard Reutner-Fischer Nov. 5, 2021, 10:08 p.m. UTC | #4
On Fri, 5 Nov 2021 19:46:16 +0100
Mikael Morin <morin-mikael@orange.fr> wrote:

> Le 29/10/2021 à 01:58, Bernhard Reutner-Fischer via Fortran a écrit :
> > On Wed, 27 Oct 2021 23:39:43 +0200
> > Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
> >   
> >> Ping
> >> [hmz. it's been a while, I'll rebase and retest this one.
> >> Ok if it passes?]  
> > Testing passed without any new regressions.
> > Ok for trunk?
> > thanks,  
> >>
> >> On Mon, 15 Oct 2018 10:23:06 +0200
> >> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
> >>  
> >>> If a finalization is not required we created a namespace containing
> >>> formal arguments for an internal interface definition but never used
> >>> any of these. So the whole sub_ns namespace was not wired up to the
> >>> program and consequently was never freed. The fix is to simply not
> >>> generate any finalization wrappers if we know that it will be unused.
> >>> Note that this reverts back to the original r190869
> >>> (8a96d64282ac534cb597f446f02ac5d0b13249cc) handling for this case
> >>> by reverting this specific part of r194075
> >>> (f1ee56b4be7cc3892e6ccc75d73033c129098e87) for PR fortran/37336.
> >>>  
> I’m a bit concerned by the loss of the null_expr’s type interface.
> I can’t convince myself that it’s either absolutely necessary or 
> completely useless.

It's a delicate spot, yes, but i do think they are completely useless.
If we do NOT need a finalization, the initializer can (and has to be
AFAIU) be a null_expr and AFAICS then does not need an interface.

> Tobias didn’t include a test in his commit unfortunately, but I bet he 
> did the change on purpose.
> Don’t you get the same effect on the memory leaks if you keep just the 
> following hunk?

No, i don't think emitting the finalization-wrappers unconditionally is
correct. In
https://gcc.gnu.org/pipermail/gcc-patches/2021-October/582894.html
i noted:
---8<---
We were generating (and emitting to modules) finalization wrapper
needlessly, i.e. even when they were not called for.

This 1) leaked like shown in the initial submission and
2) polluted module files with unwarranted (wrong) mention of
finalization wrappers even when compiling without any coarray stuff.

E.g. a modified udr10.f90 (from libgomp) has the following diff in the
module which illustrates the positive side-effect of the fix:

-26 'array' '' '' 25 ((VARIABLE INOUT UNKNOWN-PROC UNKNOWN UNKNOWN 0 0
-ARTIFICIAL DIMENSION CONTIGUOUS DUMMY) () (DERIVED 3 0 0 0 DERIVED ()) 0
-0 () (0 0 ASSUMED_RANK) 0 () () () 0 0)
-27 'byte_stride' '' '' 25 ((VARIABLE UNKNOWN-INTENT UNKNOWN-PROC UNKNOWN
-UNKNOWN 0 0 ARTIFICIAL VALUE DUMMY) () (INTEGER 8 0 0 0 INTEGER ()) 0 0
-() () 0 () () () 0 0)
-28 'fini_coarray' '' '' 25 ((VARIABLE UNKNOWN-INTENT UNKNOWN-PROC
-UNKNOWN UNKNOWN 0 0 ARTIFICIAL VALUE DUMMY) () (LOGICAL 1 0 0 0 LOGICAL
-()) 0 0 () () 0 () () () 0 0)
---8<---
[Should be visible with the original udr10.f90 too.]

If something in a module would trigger finalization to be emitted
legitimately then this will continue to work as before. But IMHO
it is not proper to emit them in an undue manner. Hence it does not
help to just wire the sub_ns up in the program when it should not be
wired up (and not generated in the first place) I'd say.

> 
>  >>> @@ -1605,8 +1608,7 @@ generate_finalization_wrapper (gfc_symbol   
> *derived, gfc_namespace *ns,
>  >>>     /* Set up the namespace.  */
>  >>>     sub_ns = gfc_get_namespace (ns, 0);
>  >>>     sub_ns->sibling = ns->contained;
>  >>> -  if (!expr_null_wrapper)
>  >>> -    ns->contained = sub_ns;
>  >>> +  ns->contained = sub_ns;
>  >>>     sub_ns->resolved = 1;
>  >>>
>  >>>     /* Set up the procedure symbol.  */  
> 
> 
> The rest of the changes (appart from class.c) are mostly OK with the nit 
> below and should be put in their own commit.
> 
>  >>> @@ -3826,10 +3828,8 @@ free_tb_tree (gfc_symtree *t)
>  >>>
>  >>>     free_tb_tree (t->left);
>  >>>     free_tb_tree (t->right);
>  >>> -
>  >>> -  /* TODO: Free type-bound procedure structs themselves; probably   
> needs some
>  >>> -     sort of ref-counting mechanism.  */
>  >>>     free (t->n.tb);  
> 
> Please keep a comment; it remains somehow valid but could be updated 
> maybe: gfc_typebound_proc’s u.generic field for example is nowhere freed 
> as far as I know.

Well that's a valid point, not sure where they are freed indeed.
Do you have a specific testcase in mind that leaks tbp's u.generic (or
specific for that matter) for me to look at?

I'm happy to change the comment to
TODO: Free type-bound procedure u.generic and u.specific fields
to reflect the current state. Ok?
> 
> Thanks.

Many thanks for looking at the patch!
> 
> Mikael
Mikael Morin Nov. 6, 2021, 10:30 a.m. UTC | #5
Le 05/11/2021 à 19:46, Mikael Morin a écrit :
> Don’t you get the same effect on the memory leaks if you keep just the 
> following hunk?
> 
>  >>> @@ -1605,8 +1608,7 @@ generate_finalization_wrapper (gfc_symbol 
> *derived, gfc_namespace *ns,
>  >>>     /* Set up the namespace.  */
>  >>>     sub_ns = gfc_get_namespace (ns, 0);
>  >>>     sub_ns->sibling = ns->contained;
>  >>> -  if (!expr_null_wrapper)
>  >>> -    ns->contained = sub_ns;
>  >>> +  ns->contained = sub_ns;
>  >>>     sub_ns->resolved = 1;
>  >>>
>  >>>     /* Set up the procedure symbol.  */
> 

That’s probably not a good idea on second thought; it’s preferable to 
leak memory and not generate an empty finalization procedure.
Mikael Morin Nov. 6, 2021, 12:04 p.m. UTC | #6
Sorry, I hadn’t seen your message.

Le 05/11/2021 à 23:08, Bernhard Reutner-Fischer a écrit :
> On Fri, 5 Nov 2021 19:46:16 +0100
> Mikael Morin <morin-mikael@orange.fr> wrote:
> 
>> Le 29/10/2021 à 01:58, Bernhard Reutner-Fischer via Fortran a écrit :
>>> On Wed, 27 Oct 2021 23:39:43 +0200
>>> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
>>>    
>>>> On Mon, 15 Oct 2018 10:23:06 +0200
>>>> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
>>>>   
>>>>> If a finalization is not required we created a namespace containing
>>>>> formal arguments for an internal interface definition but never used
>>>>> any of these. So the whole sub_ns namespace was not wired up to the
>>>>> program and consequently was never freed. The fix is to simply not
>>>>> generate any finalization wrappers if we know that it will be unused.
>>>>> Note that this reverts back to the original r190869
>>>>> (8a96d64282ac534cb597f446f02ac5d0b13249cc) handling for this case
>>>>> by reverting this specific part of r194075
>>>>> (f1ee56b4be7cc3892e6ccc75d73033c129098e87) for PR fortran/37336.
>>>>>   
>> I’m a bit concerned by the loss of the null_expr’s type interface.
>> I can’t convince myself that it’s either absolutely necessary or
>> completely useless.
> 
> It's a delicate spot, yes, but i do think they are completely useless.
> If we do NOT need a finalization, the initializer can (and has to be
> AFAIU) be a null_expr and AFAICS then does not need an interface.
> 
Well, the null pointer itself doesn’t need a type, but I think it’s 
better if the pointer it’s assigned to has a type different from void*.
It will (hopefully) help the middle-end optimizers downstream.

I will see if I can manage to create a testcase where it makes a 
difference (don’t hold your breath, I don’t even have a bootstrapped 
compiler ready yet).


>> Don’t you get the same effect on the memory leaks if you keep just the
>> following hunk?
> 
> No, i don't think emitting the finalization-wrappers unconditionally is
> correct. 
 > (... lengthy explaination ...)
 >
Agreed, it was a poor suggestion.


>> The rest of the changes (appart from class.c) are mostly OK with the nit
>> below and should be put in their own commit.
>>
>>   >>> @@ -3826,10 +3828,8 @@ free_tb_tree (gfc_symtree *t)
>>   >>>
>>   >>>     free_tb_tree (t->left);
>>   >>>     free_tb_tree (t->right);
>>   >>> -
>>   >>> -  /* TODO: Free type-bound procedure structs themselves; probably
>> needs some
>>   >>> -     sort of ref-counting mechanism.  */
>>   >>>     free (t->n.tb);
>>
>> Please keep a comment; it remains somehow valid but could be updated
>> maybe: gfc_typebound_proc’s u.generic field for example is nowhere freed
>> as far as I know.
> 
> Well that's a valid point, not sure where they are freed indeed.
> Do you have a specific testcase in mind that leaks tbp's u.generic (or
> specific for that matter) for me to look at?
> 
Any testcase with generic typebound procedures, I guess.
typebound_generic_3.f03 for example seems like a good candidate.

> I'm happy to change the comment to
> TODO: Free type-bound procedure u.generic and u.specific fields
> to reflect the current state. Ok?
>
I don’t think specific leaks because it’s one of gfc_namespace’s 
sym_root sub-nodes, and it’s freed with gfc_namespace.
OK without "and u.specific".
Bernhard Reutner-Fischer Nov. 6, 2021, 11:56 p.m. UTC | #7
On Sat, 6 Nov 2021 13:04:07 +0100
Mikael Morin <morin-mikael@orange.fr> wrote:

> Le 05/11/2021 à 23:08, Bernhard Reutner-Fischer a écrit :
> > On Fri, 5 Nov 2021 19:46:16 +0100
> > Mikael Morin <morin-mikael@orange.fr> wrote:
> >   
> >> Le 29/10/2021 à 01:58, Bernhard Reutner-Fischer via Fortran a écrit :  
> >>> On Wed, 27 Oct 2021 23:39:43 +0200
> >>> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
> >>>      
> >>>> On Mon, 15 Oct 2018 10:23:06 +0200
> >>>> Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
> >>>>     
> >>>>> If a finalization is not required we created a namespace containing
> >>>>> formal arguments for an internal interface definition but never used
> >>>>> any of these. So the whole sub_ns namespace was not wired up to the
> >>>>> program and consequently was never freed. The fix is to simply not
> >>>>> generate any finalization wrappers if we know that it will be unused.
> >>>>> Note that this reverts back to the original r190869
> >>>>> (8a96d64282ac534cb597f446f02ac5d0b13249cc) handling for this case
> >>>>> by reverting this specific part of r194075
> >>>>> (f1ee56b4be7cc3892e6ccc75d73033c129098e87) for PR fortran/37336.
> >>>>>     
> >> I’m a bit concerned by the loss of the null_expr’s type interface.
> >> I can’t convince myself that it’s either absolutely necessary or
> >> completely useless.  
> > 
> > It's a delicate spot, yes, but i do think they are completely useless.
> > If we do NOT need a finalization, the initializer can (and has to be
> > AFAIU) be a null_expr and AFAICS then does not need an interface.
> >   
> Well, the null pointer itself doesn’t need a type, but I think it’s 
> better if the pointer it’s assigned to has a type different from void*.
> It will (hopefully) help the middle-end optimizers downstream.

I would not expect this to help all that much or at all TBH.

So i compiled
for i in $(grep -li final $(grep -L dg-error /scratch/src/gcc-12.mine/gcc/testsuite/gfortran.dg/*.f*)); do gfortran -O2 -fcoarray=single -c $i -g -g3 -ggdb3 -fdump-tree-original -fdump-tree-optimized;done
and diffed all .original and .optimized dumps against pristine trunk
and they are identical.

I inspected and ran the binary from finalize_14 and there is no change
in the leaks compared to pristine trunk. The 3 shape_w in p leak as
they used to. I do remember that finalize_14 was a good testcase, in
sum i glared at it for quite some time ;)
> 
> I will see if I can manage to create a testcase where it makes a 
> difference (don’t hold your breath, I don’t even have a bootstrapped 
> compiler ready yet).
> 
That'd be great, TIA!
[]

btw.. Just because it's vagely related.
I think f8add009ce300f24b75e9c2e2cc5dd944a020c28 for
PR fortran/88009 (ICE in find_intrinsic_vtab, at fortran/class.c:2761)
is incomplete in that i think all the internal class helpers should be
flagged artificial. All these symbols built in gfc_build_class_symbol,
generate_finalization_wrapper, gfc_find_derived_vtab etc.
Looking at the history it seems the artificial bit often was forgotten.
And most importantly i think it is not correct to ignore artificial in
gfc_check_conflict!

I'm attaching my notes on this to illustrate what i mean.
Not a patch, even if it regtests cleanly..

The hunk in gfc_match_derived_decl() plugs another leak by first
checking if the max extension level is reached before adding the
component. Maybe i should split that hunk out.
Similar to the removal of *head in gfc_match_derived_decl, there's
another spot in gfc_match_decl_type_spec which should get rid of the
*head and just wire the interface up as usual. Just cosmetics.

Several tests do exercise this code: alloc_comp_class_1.f90,
class_19.f03 and 62, unlimited_polymorphic_8.f90 and others.

> >> The rest of the changes (appart from class.c) are mostly OK with the nit
> >> below and should be put in their own commit.
> >>  
> >>   >>> @@ -3826,10 +3828,8 @@ free_tb_tree (gfc_symtree *t)
> >>   >>>
> >>   >>>     free_tb_tree (t->left);
> >>   >>>     free_tb_tree (t->right);
> >>   >>> -
> >>   >>> -  /* TODO: Free type-bound procedure structs themselves; probably  
> >> needs some  
> >>   >>> -     sort of ref-counting mechanism.  */
> >>   >>>     free (t->n.tb);  
> >>
> >> Please keep a comment; it remains somehow valid but could be updated
> >> maybe: gfc_typebound_proc’s u.generic field for example is nowhere freed
> >> as far as I know.  
> > 
> > Well that's a valid point, not sure where they are freed indeed.
> > Do you have a specific testcase in mind that leaks tbp's u.generic (or
> > specific for that matter) for me to look at?
> >   
> Any testcase with generic typebound procedures, I guess.
> typebound_generic_3.f03 for example seems like a good candidate.

I'll have a look at these later, thanks for the pointer.
> 
> > I'm happy to change the comment to
> > TODO: Free type-bound procedure u.generic and u.specific fields
> > to reflect the current state. Ok?
> >  
> I don’t think specific leaks because it’s one of gfc_namespace’s 
> sym_root sub-nodes, and it’s freed with gfc_namespace.
> OK without "and u.specific".

Ah right. Done.

Thanks so far!
diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
index 6b017667600..44fccced7b9 100644
--- a/gcc/fortran/class.c
+++ b/gcc/fortran/class.c
@@ -637,7 +637,7 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
 			gfc_array_spec **as)
 {
   char tname[GFC_MAX_SYMBOL_LEN+1];
-  char *name;
+  const char *name;
   gfc_symbol *fclass;
   gfc_symbol *vtab;
   gfc_component *c;
@@ -665,17 +665,17 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
 
   get_unique_hashed_string (tname, ts->u.derived);
   if ((*as) && attr->allocatable)
-    name = xasprintf ("__class_%s_%d_%da", tname, rank, (*as)->corank);
+    name = gfc_get_string ("__class_%s_%d_%da", tname, rank, (*as)->corank);
   else if ((*as) && attr->pointer)
-    name = xasprintf ("__class_%s_%d_%dp", tname, rank, (*as)->corank);
+    name = gfc_get_string ("__class_%s_%d_%dp", tname, rank, (*as)->corank);
   else if ((*as))
-    name = xasprintf ("__class_%s_%d_%dt", tname, rank, (*as)->corank);
+    name = gfc_get_string ("__class_%s_%d_%dt", tname, rank, (*as)->corank);
   else if (attr->pointer)
-    name = xasprintf ("__class_%s_p", tname);
+    name = gfc_get_string ("__class_%s_p", tname);
   else if (attr->allocatable)
-    name = xasprintf ("__class_%s_a", tname);
+    name = gfc_get_string ("__class_%s_a", tname);
   else
-    name = xasprintf ("__class_%s_t", tname);
+    name = gfc_get_string ("__class_%s_t", tname);
 
   if (ts->u.derived->attr.unlimited_polymorphic)
     {
@@ -695,7 +695,7 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
   if (attr->dummy && !attr->codimension && (*as)
       && !((*as)->type == AS_DEFERRED || (*as)->type == AS_ASSUMED_RANK))
     {
-      char *sname;
+      const char *sname;
       ns = gfc_current_ns;
       gfc_find_symbol (name, ns, 0, &fclass);
       /* If a local class type with this name already exists, update the
@@ -703,8 +703,7 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
       if (fclass)
 	{
 	  fclass = NULL;
-	  sname = xasprintf ("%s_%d", name, ++ctr);
-	  free (name);
+	  sname = gfc_get_string ("%s_%d", name, ++ctr);
 	  name = sname;
 	}
     }
@@ -735,6 +734,7 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
       c->ts.type = BT_DERIVED;
       c->attr.access = ACCESS_PRIVATE;
       c->ts.u.derived = ts->u.derived;
+      c->attr.artificial = 1;
       c->attr.class_pointer = attr->pointer;
       c->attr.pointer = attr->pointer || (attr->dummy && !attr->allocatable)
 			|| attr->select_type_temporary;
@@ -742,7 +742,7 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
       c->attr.dimension = attr->dimension;
       c->attr.codimension = attr->codimension;
       c->attr.abstract = fclass->attr.abstract;
-      c->as = (*as);
+      c->as = *as;
       c->initializer = NULL;
 
       /* Add component '_vptr'.  */
@@ -751,6 +751,7 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
       c->ts.type = BT_DERIVED;
       c->attr.access = ACCESS_PRIVATE;
       c->attr.pointer = 1;
+      c->attr.artificial = 1;
 
       if (ts->u.derived->attr.unlimited_polymorphic)
 	{
@@ -792,8 +793,7 @@ gfc_build_class_symbol (gfc_typespec *ts, symbol_attribute *attr,
   fclass->attr.is_class = 1;
   ts->u.derived = fclass;
   attr->allocatable = attr->pointer = attr->dimension = attr->codimension = 0;
-  (*as) = NULL;
-  free (name);
+  *as = NULL;
   return true;
 }
 
@@ -1600,7 +1600,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   gfc_component *comp;
   gfc_namespace *sub_ns;
   gfc_code *last_code, *block;
-  char *name;
+  const char *name;
   bool finalizable_comp = false;
   gfc_expr *ancestor_wrapper = NULL, *rank;
   gfc_iterator *iter;
@@ -1681,7 +1681,7 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   sub_ns->resolved = 1;
 
   /* Set up the procedure symbol.  */
-  name = xasprintf ("__final_%s", tname);
+  name = gfc_get_string ("__final_%s", tname);
   gfc_get_symbol (name, sub_ns, &final);
   sub_ns->proc_name = final;
   final->attr.flavor = FL_PROCEDURE;
@@ -2238,7 +2238,6 @@ generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   gfc_free_expr (rank);
   vtab_final->initializer = gfc_lval_expr_from_sym (final);
   vtab_final->ts.interface = final;
-  free (name);
 }
 
 
@@ -2313,10 +2312,10 @@ gfc_find_derived_vtab (gfc_symbol *derived)
   if (ns)
     {
       char tname[GFC_MAX_SYMBOL_LEN+1];
-      char *name;
+      const char *name;
 
       get_unique_hashed_string (tname, derived);
-      name = xasprintf ("__vtab_%s", tname);
+      name = gfc_get_string ("__vtab_%s", tname);
 
       /* Look for the vtab symbol in various namespaces.  */
       if (gsym && gsym->ns)
@@ -2344,7 +2343,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 	  vtab->attr.vtab = 1;
 	  vtab->attr.access = ACCESS_PUBLIC;
 	  gfc_set_sym_referenced (vtab);
-	  name = xasprintf ("__vtype_%s", tname);
+	  name = gfc_get_string ("__vtype_%s", tname);
 
 	  gfc_find_symbol (name, ns, 0, &vtype);
 	  if (vtype == NULL)
@@ -2372,6 +2371,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 		goto cleanup;
 	      vtype->attr.access = ACCESS_PUBLIC;
 	      vtype->attr.vtype = 1;
+	      vtype->attr.artificial = 1;
 	      gfc_set_sym_referenced (vtype);
 
 	      /* Add component '_hash'.  */
@@ -2380,6 +2380,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 	      c->ts.type = BT_INTEGER;
 	      c->ts.kind = 4;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      c->initializer = gfc_get_int_expr (gfc_default_integer_kind,
 						 NULL, derived->hash_value);
 
@@ -2389,6 +2390,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 	      c->ts.type = BT_INTEGER;
 	      c->ts.kind = gfc_size_kind;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      /* Remember the derived type in ts.u.derived,
 		 so that the correct initializer can be set later on
 		 (in gfc_conv_structure).  */
@@ -2401,6 +2403,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 		goto cleanup;
 	      c->attr.pointer = 1;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      if (!derived->attr.unlimited_polymorphic)
 		parent = gfc_get_derived_super_type (derived);
 	      else
@@ -2447,7 +2450,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 	      else
 		{
 		  /* Construct default initialization variable.  */
-		  name = xasprintf ("__def_init_%s", tname);
+		  name = gfc_get_string ("__def_init_%s", tname);
 		  gfc_get_symbol (name, ns, &def_init);
 		  def_init->attr.target = 1;
 		  def_init->attr.artificial = 1;
@@ -2467,6 +2470,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 		goto cleanup;
 	      c->attr.proc_pointer = 1;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      c->tb = XCNEW (gfc_typebound_proc);
 	      c->tb->ppc = 1;
 	      if (derived->attr.unlimited_polymorphic
@@ -2480,7 +2484,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 		  ns->contained = sub_ns;
 		  sub_ns->resolved = 1;
 		  /* Set up procedure symbol.  */
-		  name = xasprintf ("__copy_%s", tname);
+		  name = gfc_get_string ("__copy_%s", tname);
 		  gfc_get_symbol (name, sub_ns, &copy);
 		  sub_ns->proc_name = copy;
 		  copy->attr.flavor = FL_PROCEDURE;
@@ -2543,6 +2547,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 		goto cleanup;
 	      c->attr.proc_pointer = 1;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      c->tb = XCNEW (gfc_typebound_proc);
 	      c->tb->ppc = 1;
 	      if (derived->attr.unlimited_polymorphic
@@ -2558,7 +2563,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 		  ns->contained = sub_ns;
 		  sub_ns->resolved = 1;
 		  /* Set up procedure symbol.  */
-		  name = xasprintf ("__deallocate_%s", tname);
+		  name = gfc_get_string ("__deallocate_%s", tname);
 		  gfc_get_symbol (name, sub_ns, &dealloc);
 		  sub_ns->proc_name = dealloc;
 		  dealloc->attr.flavor = FL_PROCEDURE;
@@ -2607,7 +2612,6 @@ have_vtype:
 	  vtab->ts.u.derived = vtype;
 	  vtab->value = gfc_default_initializer (&vtab->ts);
 	}
-      free (name);
     }
 
   found_sym = vtab;
@@ -2700,13 +2704,13 @@ find_intrinsic_vtab (gfc_typespec *ts)
   if (ns)
     {
       char tname[GFC_MAX_SYMBOL_LEN+1];
-      char *name;
+      const char *name;
 
       /* Encode all types as TYPENAME_KIND_ including especially character
 	 arrays, whose length is now consistently stored in the _len component
 	 of the class-variable.  */
       sprintf (tname, "%s_%d_", gfc_basic_typename (ts->type), ts->kind);
-      name = xasprintf ("__vtab_%s", tname);
+      name = gfc_get_string ("__vtab_%s", tname);
 
       /* Look for the vtab symbol in the top-level namespace only.  */
       gfc_find_symbol (name, ns, 0, &vtab);
@@ -2722,8 +2726,9 @@ find_intrinsic_vtab (gfc_typespec *ts)
 	  vtab->attr.save = SAVE_IMPLICIT;
 	  vtab->attr.vtab = 1;
 	  vtab->attr.access = ACCESS_PUBLIC;
+	  vtab->attr.artificial = 1;
 	  gfc_set_sym_referenced (vtab);
-	  name = xasprintf ("__vtype_%s", tname);
+	  name = gfc_get_string ("__vtype_%s", tname);
 
 	  gfc_find_symbol (name, ns, 0, &vtype);
 	  if (vtype == NULL)
@@ -2740,6 +2745,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
 				   &gfc_current_locus))
 		goto cleanup;
 	      vtype->attr.access = ACCESS_PUBLIC;
+	      vtype->attr.artificial = 1;
 	      vtype->attr.vtype = 1;
 	      gfc_set_sym_referenced (vtype);
 
@@ -2749,6 +2755,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
 	      c->ts.type = BT_INTEGER;
 	      c->ts.kind = 4;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      hash = gfc_intrinsic_hash_value (ts);
 	      c->initializer = gfc_get_int_expr (gfc_default_integer_kind,
 						 NULL, hash);
@@ -2759,6 +2766,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
 	      c->ts.type = BT_INTEGER;
 	      c->ts.kind = gfc_size_kind;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 
 	      /* Build a minimal expression to make use of
 		 target-memory.c/gfc_element_size for 'size'.  Special handling
@@ -2782,6 +2790,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
 		goto cleanup;
 	      c->attr.pointer = 1;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      c->ts.type = BT_VOID;
 	      c->initializer = gfc_get_null_expr (NULL);
 
@@ -2790,6 +2799,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
 		goto cleanup;
 	      c->attr.pointer = 1;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      c->ts.type = BT_VOID;
 	      c->initializer = gfc_get_null_expr (NULL);
 
@@ -2798,16 +2808,17 @@ find_intrinsic_vtab (gfc_typespec *ts)
 		goto cleanup;
 	      c->attr.proc_pointer = 1;
 	      c->attr.access = ACCESS_PRIVATE;
+	      c->attr.artificial = 1;
 	      c->tb = XCNEW (gfc_typebound_proc);
 	      c->tb->ppc = 1;
 
 	      if (ts->type != BT_CHARACTER)
-		name = xasprintf ("__copy_%s", tname);
+		name = gfc_get_string ("__copy_%s", tname);
 	      else
 		{
 		  /* __copy is always the same for characters.
 		     Check to see if copy function already exists.  */
-		  name = xasprintf ("__copy_character_%d", ts->kind);
+		  name = gfc_get_string ("__copy_character_%d", ts->kind);
 		  contained = ns->contained;
 		  for (; contained; contained = contained->sibling)
 		    if (contained->proc_name
@@ -2829,6 +2840,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
 	      copy->attr.flavor = FL_PROCEDURE;
 	      copy->attr.subroutine = 1;
 	      copy->attr.pure = 1;
+	      copy->attr.artificial = 1;
 	      copy->attr.if_source = IFSRC_DECL;
 	      /* This is elemental so that arrays are automatically
 		 treated correctly by the scalarizer.  */
@@ -2851,6 +2863,7 @@ find_intrinsic_vtab (gfc_typespec *ts)
 	      dst->ts.kind = ts->kind;
 	      dst->attr.flavor = FL_VARIABLE;
 	      dst->attr.dummy = 1;
+	      dst->attr.artificial = 1;
 	      dst->attr.intent = INTENT_INOUT;
 	      gfc_set_sym_referenced (dst);
 	      copy->formal->next = gfc_get_formal_arglist ();
@@ -2877,7 +2890,6 @@ find_intrinsic_vtab (gfc_typespec *ts)
 	  vtab->ts.u.derived = vtype;
 	  vtab->value = gfc_default_initializer (&vtab->ts);
 	}
-      free (name);
     }
 
   found_sym = vtab;
diff --git a/gcc/fortran/decl.c b/gcc/fortran/decl.c
index ab88ab5e9c1..04aa43af1d5 100644
--- a/gcc/fortran/decl.c
+++ b/gcc/fortran/decl.c
@@ -4458,7 +4458,7 @@ gfc_match_decl_type_spec (gfc_typespec *ts, int implicit_flag)
 	      upe->attr.zero_comp = 1;
 	      if (!gfc_add_flavor (&upe->attr, FL_DERIVED, NULL,
 				   &gfc_current_locus))
-	      return MATCH_ERROR;
+		return MATCH_ERROR;
 	    }
 	  else
 	    {
@@ -8342,7 +8342,7 @@ gfc_match_end (gfc_statement *st)
     case COMP_SUBROUTINE:
       *st = ST_END_SUBROUTINE;
       if (!abreviated_modproc_decl)
-      target = " subroutine";
+	target = " subroutine";
       else
 	target = " procedure";
       eos_ok = !contained_procedure ();
@@ -8351,7 +8351,7 @@ gfc_match_end (gfc_statement *st)
     case COMP_FUNCTION:
       *st = ST_END_FUNCTION;
       if (!abreviated_modproc_decl)
-      target = " function";
+	target = " function";
       else
 	target = " procedure";
       eos_ok = !contained_procedure ();
@@ -10473,7 +10473,7 @@ gfc_match_derived_decl (void)
   match m;
   match is_type_attr_spec = MATCH_NO;
   bool seen_attr = false;
-  gfc_interface *intr = NULL, *head;
+  gfc_interface *intr = NULL;
   bool parameterized_type = false;
   bool seen_colons = false;
 
@@ -10498,16 +10498,15 @@ gfc_match_derived_decl (void)
      been added to 'attr' but now the parent type must be found and
      checked.  */
   if (parent[0])
-    extended = check_extended_derived_type (parent);
-
-  if (parent[0] && !extended)
-    return MATCH_ERROR;
+    {
+      extended = check_extended_derived_type (parent);
+      if (extended == NULL)
+	return MATCH_ERROR;
+    }
 
   m = gfc_match (" ::");
   if (m == MATCH_YES)
-    {
-      seen_colons = true;
-    }
+    seen_colons = true;
   else if (seen_attr)
     {
       gfc_error ("Expected :: in TYPE definition at %C");
@@ -10582,7 +10581,7 @@ gfc_match_derived_decl (void)
   if (gensym->attr.dummy)
     {
       gfc_error ("Dummy argument %qs at %L cannot be a derived type at %C",
-		 name, &gensym->declared_at);
+		 gensym->name, &gensym->declared_at);
       return MATCH_ERROR;
     }
 
@@ -10599,13 +10598,12 @@ gfc_match_derived_decl (void)
     {
       /* Use upper case to save the actual derived-type symbol.  */
       gfc_get_symbol (gfc_dt_upper_string (gensym->name), NULL, &sym);
-      sym->name = gfc_get_string ("%s", gensym->name);
-      head = gensym->generic;
+      sym->name = gensym->name;
+      sym->declared_at = gfc_current_locus;
       intr = gfc_get_interface ();
       intr->sym = sym;
       intr->where = gfc_current_locus;
-      intr->sym->declared_at = gfc_current_locus;
-      intr->next = head;
+      intr->next = gensym->generic;
       gensym->generic = intr;
       gensym->attr.if_source = IFSRC_DECL;
     }
@@ -10662,15 +10660,6 @@ gfc_match_derived_decl (void)
       gfc_component *p;
       gfc_formal_arglist *f, *g, *h;
 
-      /* Add the extended derived type as the first component.  */
-      gfc_add_component (sym, parent, &p);
-      extended->refs++;
-      gfc_set_sym_referenced (extended);
-
-      p->ts.type = BT_DERIVED;
-      p->ts.u.derived = extended;
-      p->initializer = gfc_default_initializer (&p->ts);
-
       /* Set extension level.  */
       if (extended->attr.extension == 255)
 	{
@@ -10680,6 +10669,16 @@ gfc_match_derived_decl (void)
 		     extended->name, &extended->declared_at);
 	  return MATCH_ERROR;
 	}
+
+      /* Add the extended derived type as the first component.  */
+      gfc_add_component (sym, parent, &p);
+      extended->refs++;
+      gfc_set_sym_referenced (extended);
+
+      p->ts.type = BT_DERIVED;
+      p->ts.u.derived = extended;
+      p->initializer = gfc_default_initializer (&p->ts);
+
       sym->attr.extension = extended->attr.extension + 1;
 
       /* Provide the links between the extended type and its extension.  */
diff --git a/gcc/fortran/parse.c b/gcc/fortran/parse.c
index 12aa80ec45c..fcbff0c1dcf 100644
--- a/gcc/fortran/parse.c
+++ b/gcc/fortran/parse.c
@@ -3581,6 +3581,7 @@ parse_derived (void)
 	{
 	case ST_NONE:
 	  unexpected_eof ();
+	  break; /* never reached */
 
 	case ST_DATA_DECL:
 	case ST_PROCEDURE:
@@ -3640,9 +3641,7 @@ endType:
 			 "TYPE statement");
 
 	  if (seen_sequence)
-	    {
-	      gfc_error ("Duplicate SEQUENCE statement at %C");
-	    }
+	    gfc_error ("Duplicate SEQUENCE statement at %C");
 
 	  seen_sequence = 1;
 	  gfc_add_sequence (&gfc_current_block ()->attr,
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 1f4abd08720..a9a1103e049 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -2588,7 +2588,7 @@ resolve_global_procedure (gfc_symbol *sym, locus *where, int sub)
   gsym = gfc_get_gsymbol (sym->binding_label ? sym->binding_label : sym->name,
 			  sym->binding_label != NULL);
 
-  if ((gsym->type != GSYM_UNKNOWN && gsym->type != type))
+  if (gsym->type != GSYM_UNKNOWN && gsym->type != type)
     gfc_global_used (gsym, where);
 
   if ((sym->attr.if_source == IFSRC_UNKNOWN
diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c
index 91798f2a3a5..1a1e4551355 100644
--- a/gcc/fortran/symbol.c
+++ b/gcc/fortran/symbol.c
@@ -440,9 +440,6 @@ gfc_check_conflict (symbol_attribute *attr, const char *name, locus *where)
   const char *a1, *a2;
   int standard;
 
-  if (attr->artificial)
-    return true;
-
   if (where == NULL)
     where = &gfc_current_locus;
 
@@ -1773,7 +1770,7 @@ gfc_add_flavor (symbol_attribute *attr, sym_flavor f, const char *name,
   /* Copying a procedure dummy argument for a module procedure in a
      submodule results in the flavor being copied and would result in
      an error without this.  */
-  if (attr->flavor == f && f == FL_PROCEDURE
+  if (f == FL_PROCEDURE && attr->flavor == f
       && gfc_new_block && gfc_new_block->abr_modproc_decl)
     return true;
 
@@ -3155,7 +3152,6 @@ gfc_new_symbol (const char *name, gfc_namespace *ns)
   gfc_symbol *p;
 
   p = XCNEW (gfc_symbol);
-
   gfc_clear_ts (&p->ts);
   gfc_clear_attr (&p->attr);
   p->ns = ns;
@@ -3397,7 +3393,6 @@ gfc_get_sym_tree (const char *name, gfc_namespace *ns, gfc_symtree **result,
       p = gfc_new_symbol (name, ns);
 
       /* Add to the list of tentative symbols.  */
-      p->old_symbol = NULL;
       p->mark = 1;
       p->gfc_new = 1;
       latest_undo_chgset->syms.safe_push (p);
@@ -3405,7 +3400,6 @@ gfc_get_sym_tree (const char *name, gfc_namespace *ns, gfc_symtree **result,
       st = gfc_new_symtree (&ns->sym_root, name);
       st->n.sym = p;
       p->refs++;
-
     }
   else
     {
@@ -4835,9 +4829,7 @@ generate_isocbinding_symbol (const char *mod_name, iso_c_binding_symbol s,
 	      gfc_derived_types->dt_next = tmp_sym;
 	    }
 	  else
-	    {
-	      tmp_sym->dt_next = tmp_sym;
-	    }
+	    tmp_sym->dt_next = tmp_sym;
 	  gfc_derived_types = tmp_sym;
         }
 
@@ -5013,9 +5005,7 @@ generate_isocbinding_symbol (const char *mod_name, iso_c_binding_symbol s,
 	      gfc_derived_types->dt_next = dt_sym;
 	    }
 	  else
-	    {
-	      dt_sym->dt_next = dt_sym;
-	    }
+	    dt_sym->dt_next = dt_sym;
 	  gfc_derived_types = dt_sym;
 
 	  gfc_add_component (dt_sym, "c_address", &tmp_comp);
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index e7aec3845d3..56ddb6629bc 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -9033,7 +9033,7 @@ gfc_trans_subcomponent_assign (tree dest, gfc_component * cm, gfc_expr * expr,
 	  gfc_add_expr_to_block (&block, tmp);
 	}
     }
-  else if (!cm->attr.artificial)
+  else
     {
       /* Scalar component (excluding deferred parameters).  */
       gfc_init_se (&se, NULL);
Mikael Morin Nov. 7, 2021, 12:32 p.m. UTC | #8
Le 07/11/2021 à 00:56, Bernhard Reutner-Fischer a écrit :
> On Sat, 6 Nov 2021 13:04:07 +0100
> Mikael Morin <morin-mikael@orange.fr> wrote:
> 
>> Le 05/11/2021 à 23:08, Bernhard Reutner-Fischer a écrit :
>>> On Fri, 5 Nov 2021 19:46:16 +0100
>>> Mikael Morin <morin-mikael@orange.fr> wrote:
>>>    
>>>> I’m a bit concerned by the loss of the null_expr’s type interface.
>>>> I can’t convince myself that it’s either absolutely necessary or
>>>> completely useless.
>>>
>>> It's a delicate spot, yes, but i do think they are completely useless.
>>> If we do NOT need a finalization, the initializer can (and has to be
>>> AFAIU) be a null_expr and AFAICS then does not need an interface.
>>>    
>> Well, the null pointer itself doesn’t need a type, but I think it’s
>> better if the pointer it’s assigned to has a type different from void*.
>> It will (hopefully) help the middle-end optimizers downstream.
> 
> I would not expect this to help all that much or at all TBH.
> 
> So i compiled
> for i in $(grep -li final $(grep -L dg-error /scratch/src/gcc-12.mine/gcc/testsuite/gfortran.dg/*.f*)); do gfortran -O2 -fcoarray=single -c $i -g -g3 -ggdb3 -fdump-tree-original -fdump-tree-optimized;done
> and diffed all .original and .optimized dumps against pristine trunk
> and they are identical.
> 
> I inspected and ran the binary from finalize_14 and there is no change
> in the leaks compared to pristine trunk. The 3 shape_w in p leak as
> they used to. I do remember that finalize_14 was a good testcase, in
> sum i glared at it for quite some time ;)

In fact, the interface is not used.
the type is built in gfc_get_ppc_type which has the following.

   /* Explicit interface.  */
   if (c->attr.if_source != IFSRC_UNKNOWN && c->ts.interface)
     return build_pointer_type (gfc_get_function_type (c->ts.interface));

As components have no if_source attribute set, the type is not built 
here and a default function type is built further down without interface 
information.
This is probably unintended as the components’ initializers carefully 
set an if_source attribute.

The problem has been identified before ; see vaguely related posts from 
FX in september 2020.

Anyway, I don’t think your changes will have negative impact then, and 
it makes things more readable, so I’m fine with it after all; OK.

>>
>> I will see if I can manage to create a testcase where it makes a
>> difference (don’t hold your breath, I don’t even have a bootstrapped
>> compiler ready yet).
>>
> That'd be great, TIA!
> []
> 
I’ve given up eventually.

> btw.. Just because it's vagely related.
> I think f8add009ce300f24b75e9c2e2cc5dd944a020c28 for
> PR fortran/88009 (ICE in find_intrinsic_vtab, at fortran/class.c:2761)
> is incomplete in that i think all the internal class helpers should be
> flagged artificial. All these symbols built in gfc_build_class_symbol,
> generate_finalization_wrapper, gfc_find_derived_vtab etc.
> Looking at the history it seems the artificial bit often was forgotten.

I guess so, yes...

> And most importantly i think it is not correct to ignore artificial in
> gfc_check_conflict!
> 
Well, it’s not correct to throw errors at users for things they haven’t 
written and that they don’t control.
Bernhard Reutner-Fischer Nov. 14, 2021, 7:53 p.m. UTC | #9
On Sun, 7 Nov 2021 13:32:34 +0100
Mikael Morin <morin-mikael@orange.fr> wrote:

> > btw.. Just because it's vagely related.
> > I think f8add009ce300f24b75e9c2e2cc5dd944a020c28 for
> > PR fortran/88009 (ICE in find_intrinsic_vtab, at fortran/class.c:2761)
> > is incomplete in that i think all the internal class helpers should be
> > flagged artificial. All these symbols built in gfc_build_class_symbol,
> > generate_finalization_wrapper, gfc_find_derived_vtab etc.
> > Looking at the history it seems the artificial bit often was forgotten.  
> 
> I guess so, yes...
> 
> > And most importantly i think it is not correct to ignore artificial in
> > gfc_check_conflict!
> >   
> Well, it’s not correct to throw errors at users for things they haven’t 
> written and that they don’t control.

oops, i forgot to add the hunk to the patch to drain complaints to
the user 1).

Of course we don't want the error to be user-visible, but i think we do
want to check_conflicts (e.g. gfortran.dg/pr95587.f90 regresses via an
unspecific Unclassifiable statement; I assume we should copy all or at
least some sym attribs to the corresponding CLASS_DATA attribs which i
think makes sense for consistency anyway).

1)
diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c
index 1a1e4551355..9df23f314df 100644
--- a/gcc/fortran/symbol.c
+++ b/gcc/fortran/symbol.c
@@ -898,6 +898,10 @@ gfc_check_conflict (symbol_attribute *attr, const char *name, locus *where)
   return true;
 
 conflict:
+  /* It would be wrong to complain about artificial code.  */
+  if (attr->artificial)
+    return false;
+
   if (name == NULL)
     gfc_error ("%s attribute conflicts with %s attribute at %L",
 	       a1, a2, where);
diff mbox series

Patch

diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
index 69c95fc5dfa..e0bb381a55f 100644
--- a/gcc/fortran/class.c
+++ b/gcc/fortran/class.c
@@ -1533,7 +1533,6 @@  generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   gfc_code *last_code, *block;
   const char *name;
   bool finalizable_comp = false;
-  bool expr_null_wrapper = false;
   gfc_expr *ancestor_wrapper = NULL, *rank;
   gfc_iterator *iter;
 
@@ -1561,13 +1560,17 @@  generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
     }
 
   /* No wrapper of the ancestor and no own FINAL subroutines and allocatable
-     components: Return a NULL() expression; we defer this a bit to have have
+     components: Return a NULL() expression; we defer this a bit to have
      an interface declaration.  */
   if ((!ancestor_wrapper || ancestor_wrapper->expr_type == EXPR_NULL)
       && !derived->attr.alloc_comp
       && (!derived->f2k_derived || !derived->f2k_derived->finalizers)
       && !has_finalizer_component (derived))
-    expr_null_wrapper = true;
+    {
+      vtab_final->initializer = gfc_get_null_expr (NULL);
+      gcc_assert (vtab_final->ts.interface == NULL);
+      return;
+    }
   else
     /* Check whether there are new allocatable components.  */
     for (comp = derived->components; comp; comp = comp->next)
@@ -1581,7 +1584,7 @@  generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
 
   /* If there is no new finalizer and no new allocatable, return with
      an expr to the ancestor's one.  */
-  if (!expr_null_wrapper && !finalizable_comp
+  if (!finalizable_comp
       && (!derived->f2k_derived || !derived->f2k_derived->finalizers))
     {
       gcc_assert (ancestor_wrapper && ancestor_wrapper->ref == NULL
@@ -1605,8 +1608,7 @@  generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   /* Set up the namespace.  */
   sub_ns = gfc_get_namespace (ns, 0);
   sub_ns->sibling = ns->contained;
-  if (!expr_null_wrapper)
-    ns->contained = sub_ns;
+  ns->contained = sub_ns;
   sub_ns->resolved = 1;
 
   /* Set up the procedure symbol.  */
@@ -1622,7 +1624,7 @@  generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   final->ts.kind = 4;
   final->attr.artificial = 1;
   final->attr.always_explicit = 1;
-  final->attr.if_source = expr_null_wrapper ? IFSRC_IFBODY : IFSRC_DECL;
+  final->attr.if_source = IFSRC_DECL;
   if (ns->proc_name->attr.flavor == FL_MODULE)
     final->module = ns->proc_name->name;
   gfc_set_sym_referenced (final);
@@ -1672,15 +1674,6 @@  generate_finalization_wrapper (gfc_symbol *derived, gfc_namespace *ns,
   final->formal->next->next->sym = fini_coarray;
   gfc_commit_symbol (fini_coarray);
 
-  /* Return with a NULL() expression but with an interface which has
-     the formal arguments.  */
-  if (expr_null_wrapper)
-    {
-      vtab_final->initializer = gfc_get_null_expr (NULL);
-      vtab_final->ts.interface = final;
-      return;
-    }
-
   /* Local variables.  */
 
   gfc_get_symbol (gfc_get_string ("%s", "idx"), sub_ns, &idx);
diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index cc12e0a8402..3d744ec9641 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -533,7 +533,7 @@  gfc_free_actual_arglist (gfc_actual_arglist *a1)
     {
       a2 = a1->next;
       if (a1->expr)
-      gfc_free_expr (a1->expr);
+	gfc_free_expr (a1->expr);
       free (a1);
       a1 = a2;
     }
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 4612835706b..3466c42132f 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -3032,8 +3032,8 @@  gfc_user_op *gfc_get_uop (const char *);
 gfc_user_op *gfc_find_uop (const char *, gfc_namespace *);
 const char *gfc_get_uop_from_name (const char*);
 const char *gfc_get_name_from_uop (const char*);
-void gfc_free_symbol (gfc_symbol *);
-void gfc_release_symbol (gfc_symbol *);
+void gfc_free_symbol (gfc_symbol *&);
+void gfc_release_symbol (gfc_symbol *&);
 gfc_symbol *gfc_new_symbol (const char *, gfc_namespace *);
 gfc_symtree* gfc_find_symtree_in_proc (const char *, gfc_namespace *);
 int gfc_find_symbol (const char *, gfc_namespace *, int, gfc_symbol **);
@@ -3058,7 +3058,7 @@  void gfc_commit_symbols (void);
 void gfc_commit_symbol (gfc_symbol *);
 gfc_charlen *gfc_new_charlen (gfc_namespace *, gfc_charlen *);
 void gfc_free_charlen (gfc_charlen *, gfc_charlen *);
-void gfc_free_namespace (gfc_namespace *);
+void gfc_free_namespace (gfc_namespace *&);
 
 void gfc_symbol_init_2 (void);
 void gfc_symbol_done_2 (void);
diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c
index 09ad2bbf0cd..c99c106a0c0 100644
--- a/gcc/fortran/symbol.c
+++ b/gcc/fortran/symbol.c
@@ -2590,8 +2590,9 @@  free_components (gfc_component *p)
 	gfc_free_expr (p->kind_expr);
       if (p->param_list)
 	gfc_free_actual_arglist (p->param_list);
-      free (p->tb);
 
+      free (p->tb);
+      p->tb = NULL;
       free (p);
     }
 }
@@ -3070,7 +3071,7 @@  set_symbol_common_block (gfc_symbol *sym, gfc_common_head *common_block)
 /* Remove a gfc_symbol structure and everything it points to.  */
 
 void
-gfc_free_symbol (gfc_symbol *sym)
+gfc_free_symbol (gfc_symbol *&sym)
 {
 
   if (sym == NULL)
@@ -3078,8 +3079,6 @@  gfc_free_symbol (gfc_symbol *sym)
 
   gfc_free_array_spec (sym->as);
 
-  free_components (sym->components);
-
   gfc_free_expr (sym->value);
 
   gfc_free_namelist (sym->namelist);
@@ -3094,19 +3093,22 @@  gfc_free_symbol (gfc_symbol *sym)
 
   gfc_free_namespace (sym->f2k_derived);
 
+  free_components (sym->components);
+
   set_symbol_common_block (sym, NULL);
 
   if (sym->param_list)
     gfc_free_actual_arglist (sym->param_list);
 
   free (sym);
+  sym = NULL;
 }
 
 
 /* Decrease the reference counter and free memory when we reach zero.  */
 
 void
-gfc_release_symbol (gfc_symbol *sym)
+gfc_release_symbol (gfc_symbol *&sym)
 {
   if (sym == NULL)
     return;
@@ -3826,10 +3828,8 @@  free_tb_tree (gfc_symtree *t)
 
   free_tb_tree (t->left);
   free_tb_tree (t->right);
-
-  /* TODO: Free type-bound procedure structs themselves; probably needs some
-     sort of ref-counting mechanism.  */
   free (t->n.tb);
+  t->n.tb = NULL;
   free (t);
 }
 
@@ -4019,7 +4019,7 @@  free_entry_list (gfc_entry_list *el)
    taken care of when a specific name is freed.  */
 
 void
-gfc_free_namespace (gfc_namespace *ns)
+gfc_free_namespace (gfc_namespace *&ns)
 {
   gfc_namespace *p, *q;
   int i;
@@ -4057,6 +4057,7 @@  gfc_free_namespace (gfc_namespace *ns)
   gfc_free_data (ns->data);
   p = ns->contained;
   free (ns);
+  ns = NULL;
 
   /* Recursively free any contained namespaces.  */
   while (p != NULL)