[Patch, Fortran, F03] PROCEDURE w/ interface: Bogus "EXTERNAL attribute conflicts with FUNCTION attribute"

[Janus Weil <janus@gcc.gnu.org>]

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Hi all,

the attached patch is the solution that I came up with for this PR
(after two simpler but wrong attempts, see PR). The issue addressed
here is the setting of the if_source attribute for dummy procedures.
When declaring a procedure (pointer) with the PROCEDURE statement, the
attributes of the dummies (including if_source) should be copied from
the source interface (cf. gfc_copy_formal_args).

The patch was successfully regtested on x86_64-unknown-linux-gnu. Ok for trunk?

Cheers,
Janus



2012-07-16  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/53956
	* gfortran.h (gfc_copy_formal_args,gfc_copy_formal_args_ppc): Modified
	prototypes.
	* symbol.c (gfc_copy_formal_args): New argument 'if_src'. Copy if_source
	of dummy procedures.
	(gfc_copy_formal_args_ppc): Ditto.
	* resolve.c (resolve_procedure_interface): Pass IFSRC_DECL to
	gfc_copy_formal_args.
	(resolve_fl_derived0): Pass IFSRC_DECL to gfc_copy_formal_args_ppc.


2012-07-16  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/53956
	* gfortran.dg/proc_decl_28.f90: New.

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Index: gcc/fortran/symbol.c
===================================================================
--- gcc/fortran/symbol.c	(revision 189470)
+++ gcc/fortran/symbol.c	(working copy)
@@ -4049,8 +4049,7 @@ gen_shape_param (gfc_formal_arglist **head,
    reference to the list of formal arguments).  */
 
 static void
-add_proc_interface (gfc_symbol *sym, ifsrc source,
-                    gfc_formal_arglist *formal)
+add_proc_interface (gfc_symbol *sym, ifsrc source, gfc_formal_arglist *formal)
 {
 
   sym->formal = formal;
@@ -4066,7 +4065,7 @@ static void
    args based on the args of a given named interface.  */
 
 void
-gfc_copy_formal_args (gfc_symbol *dest, gfc_symbol *src)
+gfc_copy_formal_args (gfc_symbol *dest, gfc_symbol *src, ifsrc if_src)
 {
   gfc_formal_arglist *head = NULL;
   gfc_formal_arglist *tail = NULL;
@@ -4090,7 +4089,8 @@ void
       formal_arg->sym->attr = curr_arg->sym->attr;
       formal_arg->sym->ts = curr_arg->sym->ts;
       formal_arg->sym->as = gfc_copy_array_spec (curr_arg->sym->as);
-      gfc_copy_formal_args (formal_arg->sym, curr_arg->sym);
+      gfc_copy_formal_args (formal_arg->sym, curr_arg->sym,
+			    curr_arg->sym->attr.if_source);
 
       /* If this isn't the first arg, set up the next ptr.  For the
         last arg built, the formal_arg->next will never get set to
@@ -4110,7 +4110,7 @@ void
     }
 
   /* Add the interface to the symbol.  */
-  add_proc_interface (dest, IFSRC_DECL, head);
+  add_proc_interface (dest, if_src, head);
 
   /* Store the formal namespace information.  */
   if (dest->formal != NULL)
@@ -4183,7 +4183,7 @@ gfc_copy_formal_args_intr (gfc_symbol *dest, gfc_i
 
 
 void
-gfc_copy_formal_args_ppc (gfc_component *dest, gfc_symbol *src)
+gfc_copy_formal_args_ppc (gfc_component *dest, gfc_symbol *src, ifsrc if_src)
 {
   gfc_formal_arglist *head = NULL;
   gfc_formal_arglist *tail = NULL;
@@ -4207,7 +4207,8 @@ void
       formal_arg->sym->attr = curr_arg->sym->attr;
       formal_arg->sym->ts = curr_arg->sym->ts;
       formal_arg->sym->as = gfc_copy_array_spec (curr_arg->sym->as);
-      gfc_copy_formal_args (formal_arg->sym, curr_arg->sym);
+      gfc_copy_formal_args (formal_arg->sym, curr_arg->sym,
+			    curr_arg->sym->attr.if_source);
 
       /* If this isn't the first arg, set up the next ptr.  For the
         last arg built, the formal_arg->next will never get set to
@@ -4229,7 +4230,7 @@ void
   /* Add the interface to the symbol.  */
   gfc_free_formal_arglist (dest->formal);
   dest->formal = head;
-  dest->attr.if_source = IFSRC_DECL;
+  dest->attr.if_source = if_src;
 
   /* Store the formal namespace information.  */
   if (dest->formal != NULL)
Index: gcc/fortran/gfortran.h
===================================================================
--- gcc/fortran/gfortran.h	(revision 189470)
+++ gcc/fortran/gfortran.h	(working copy)
@@ -2638,9 +2638,9 @@ gfc_symbol* gfc_get_ultimate_derived_super_type (g
 bool gfc_type_is_extension_of (gfc_symbol *, gfc_symbol *);
 bool gfc_type_compatible (gfc_typespec *, gfc_typespec *);
 
-void gfc_copy_formal_args (gfc_symbol *, gfc_symbol *);
+void gfc_copy_formal_args (gfc_symbol *, gfc_symbol *, ifsrc);
 void gfc_copy_formal_args_intr (gfc_symbol *, gfc_intrinsic_sym *);
-void gfc_copy_formal_args_ppc (gfc_component *, gfc_symbol *);
+void gfc_copy_formal_args_ppc (gfc_component *, gfc_symbol *, ifsrc);
 
 void gfc_free_finalizer (gfc_finalizer *el); /* Needed in resolve.c, too  */
 
Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c	(revision 189470)
+++ gcc/fortran/resolve.c	(working copy)
@@ -173,7 +173,7 @@ resolve_procedure_interface (gfc_symbol *sym)
       sym->ts.interface = ifc;
       sym->attr.function = ifc->attr.function;
       sym->attr.subroutine = ifc->attr.subroutine;
-      gfc_copy_formal_args (sym, ifc);
+      gfc_copy_formal_args (sym, ifc, IFSRC_DECL);
 
       sym->attr.allocatable = ifc->attr.allocatable;
       sym->attr.pointer = ifc->attr.pointer;
@@ -11790,7 +11790,7 @@ resolve_fl_derived0 (gfc_symbol *sym)
 	      c->ts.interface = ifc;
 	      c->attr.function = ifc->attr.function;
 	      c->attr.subroutine = ifc->attr.subroutine;
-	      gfc_copy_formal_args_ppc (c, ifc);
+	      gfc_copy_formal_args_ppc (c, ifc, IFSRC_DECL);
 
 	      c->attr.pure = ifc->attr.pure;
 	      c->attr.elemental = ifc->attr.elemental;

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! { dg-do compile }
!
! PR 53956: [F03] PROCEDURE w/ interface: Bogus "EXTERNAL attribute conflicts with FUNCTION attribute"
!
! Contributed by James van Buskirk

  interface
    subroutine sub (a)       
      integer, external :: a
    end subroutine
  end interface

  procedure(sub) :: proc

end