Bug 36361

Similarly for:

interface
  function bar()
    real bar(:) ! wrong w/o allocatable
  end function bar
end interface
ALLOCATABLE :: bar ! <<<< WRONG
end

A related problem also occurs with the POINTER attribute:

interface
  real function bar()
  end function bar
end interface

pointer :: bar

Here I'm not really sure if it is forbidden, because one could interpret this as a procedure pointer. g95 gives the same error message as with DIMENSION (see above).

Assuming it is not forbidden, one would still have to distinguish it from:

interface
  function bar()
    real, pointer :: bar
  end function bar
end interface

This code clearly is valid (declaring a pointer-valued function).

> A related problem also occurs with the POINTER attribute:
> interface
>   real function bar()
>   end function bar
> end interface
> pointer :: bar

This allowed and means a procedure pointer. See

"5.1.2.6 EXTERNAL attribute"
"A procedure that has both the EXTERNAL and POINTER attributes is a procedure pointer."

While the following is a function (no proc pointer) with a pointer-valued return variable:

> interface
>   function bar()
>     real, pointer :: bar
>   end function bar
> end interface

Here is a first attempt to fix this. The following patch should cope with the original test case and the one in comment #1. The fix for the POINTER issues will go into my procedure pointer patch. Any other attributes we need to handle?


Index: gcc/fortran/symbol.c
===================================================================
--- gcc/fortran/symbol.c	(revision 136137)
+++ gcc/fortran/symbol.c	(working copy)
@@ -814,6 +814,14 @@ gfc_add_allocatable (symbol_attribute *a
       return FAILURE;
     }
 
+  if (attr->flavor == FL_PROCEDURE && attr->if_source == IFSRC_IFBODY
+      && gfc_find_state (COMP_INTERFACE) == FAILURE)
+    {
+      gfc_error ("Attribute ALLOCATABLE declared outside of INTERFACE "
+		 "body at %L", where);
+      return FAILURE;
+    }
+
   attr->allocatable = 1;
   return check_conflict (attr, NULL, where);
 }
@@ -832,6 +840,14 @@ gfc_add_dimension (symbol_attribute *att
       return FAILURE;
     }
 
+  if (attr->flavor == FL_PROCEDURE && attr->if_source == IFSRC_IFBODY
+      && gfc_find_state (COMP_INTERFACE) == FAILURE)
+    {
+      gfc_error ("Attribute DIMENSION of %s declared outside of INTERFACE "
+		 "body at %L", name, where);
+      return FAILURE;
+    }
+
   attr->dimension = 1;
   return check_conflict (attr, name, where);
 }
@@ -1453,6 +1469,13 @@ gfc_add_explicit_interface (gfc_symbol *
       return FAILURE;
     }
 
+  if (source == IFSRC_IFBODY && (sym->attr.dimension || sym->attr.allocatable))
+    {
+      gfc_error ("Attribute declared outside of INTERFACE body for %s at %L",
+		 sym->name, where);
+      return FAILURE;
+    }
+
   sym->formal = formal;
   sym->attr.if_source = source;
 
Index: gcc/fortran/parse.c
===================================================================
--- gcc/fortran/parse.c	(revision 136137)
+++ gcc/fortran/parse.c	(working copy)
@@ -1915,8 +1915,13 @@ loop:
 
     case ST_SUBROUTINE:
       new_state = COMP_SUBROUTINE;
-      gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
-				  gfc_new_block->formal, NULL);
+      if (gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
+				  gfc_new_block->formal, NULL) == FAILURE)
+	{
+	  reject_statement ();
+	  gfc_free_namespace (gfc_current_ns);
+	  goto loop;
+	}
       if (current_interface.type != INTERFACE_ABSTRACT &&
 	 !gfc_new_block->attr.dummy &&
 	 gfc_add_external (&gfc_new_block->attr, &gfc_current_locus) == FAILURE)
@@ -1929,8 +1934,13 @@ loop:
 
     case ST_FUNCTION:
       new_state = COMP_FUNCTION;
-      gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
-				  gfc_new_block->formal, NULL);
+      if (gfc_add_explicit_interface (gfc_new_block, IFSRC_IFBODY,
+				  gfc_new_block->formal, NULL) == FAILURE)
+	{
+	  reject_statement ();
+	  gfc_free_namespace (gfc_current_ns);
+	  goto loop;
+	}
       if (current_interface.type != INTERFACE_ABSTRACT &&
 	 !gfc_new_block->attr.dummy &&
 	 gfc_add_external (&gfc_new_block->attr, &gfc_current_locus) == FAILURE)

> Any other attributes we need to handle?
I think that's all. I looked through the list of attributes and most are not possible for procedures or are already rejected. Thus I think we have all.

Subject: Bug 36361

Author: janus
Date: Mon Jun  2 21:50:23 2008
New Revision: 136296

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=136296
Log:
2008-06-02  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/36361
	* symbol.c (gfc_add_allocatable,gfc_add_dimension,
	gfc_add_explicit_interface): Added checks.
	* decl.c (attr_decl1): Added missing "var_locus".
	* parse.c (parse_interface): Checking for errors.


2008-06-02  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/36361
	* gfortran.dg/interface_24.f90: New.

Added:
    trunk/gcc/testsuite/gfortran.dg/interface_24.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/decl.c
    trunk/gcc/fortran/parse.c
    trunk/gcc/fortran/symbol.c
    trunk/gcc/testsuite/ChangeLog

Fixed with r136296. Closing.