From f96f2f273741ea19311c6e7a6f556c09b6ff9415 Mon Sep 17 00:00:00 2001
From: Mark Doffman <mark.doffman@codethink.co.uk>
Date: Tue, 23 Jun 2015 22:59:08 +0000
Subject: [PATCH 01/23] Allow repeated compatible type specifications.

Add a check to see if a repeated type specification is compatible
with the previous specification. Only create an error on incompatible
type specifications for the same symbol.

Some fixes by Jim MacArthur <jim.macarthur@codethink.co.uk>
---

    0001-Allow-repeated-compatible-type-specifications.patch
    
    0015-Allow-redefinition-of-types-for-procedures.patch
    
    0021-Correct-internal-fault-in-select_type_9.f90.patch


diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c
index ec43e63..67ad504 100644
--- a/gcc/fortran/symbol.c
+++ b/gcc/fortran/symbol.c
@@ -1877,6 +1877,8 @@ gfc_add_type (gfc_symbol *sym, gfc_typespec *ts, locus *where)
   if (sym->attr.result && type == BT_UNKNOWN && sym->ns->proc_name)
     type = sym->ns->proc_name->ts.type;
 
+  flavor = sym->attr.flavor;
+
   if (type != BT_UNKNOWN && !(sym->attr.function && sym->attr.implicit_type)
       && !(gfc_state_stack->previous && gfc_state_stack->previous->previous
 	   && gfc_state_stack->previous->previous->state == COMP_SUBMODULE)
@@ -1886,6 +1888,20 @@ gfc_add_type (gfc_symbol *sym, gfc_typespec *ts, locus *where)
 	gfc_error ("Symbol %qs at %L conflicts with symbol from module %qs, "
 		   "use-associated at %L", sym->name, where, sym->module,
 		   &sym->declared_at);
+      else if (gfc_option.allow_std & GFC_STD_EXTRA_LEGACY)
+	{
+	  /* Ignore temporaries and class/procedure names */
+          if (sym->ts.type == BT_DERIVED || sym->ts.type == BT_CLASS || sym->ts.type == BT_PROCEDURE)
+	    return false;
+
+	  if (gfc_compare_types (&sym->ts, ts)
+	      && (flavor == FL_UNKNOWN || flavor == FL_VARIABLE || flavor == FL_PROCEDURE))
+	    {
+	      return gfc_notify_std (GFC_STD_LEGACY,
+				     "Symbol '%qs' at %L already has basic type of %s", sym->name,
+				     where, gfc_basic_typename (type));
+	    }
+	}
       else
 	gfc_error ("Symbol %qs at %L already has basic type of %s", sym->name,
 		 where, gfc_basic_typename (type));
@@ -1899,8 +1915,6 @@ gfc_add_type (gfc_symbol *sym, gfc_typespec *ts, locus *where)
       return false;
     }
 
-  flavor = sym->attr.flavor;
-
   if (flavor == FL_PROGRAM || flavor == FL_BLOCK_DATA || flavor == FL_MODULE
       || flavor == FL_LABEL
       || (flavor == FL_PROCEDURE && sym->attr.subroutine)
diff --git a/gcc/testsuite/gfortran.dg/duplicate_type_4.f90 b/gcc/testsuite/gfortran.dg/duplicate_type_4.f90
new file mode 100644
index 0000000..cdd29ea
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/duplicate_type_4.f90
@@ -0,0 +1,13 @@
+! { dg-do compile }
+! { dg-options "-std=f95" }
+
+! PR fortran/30239
+! Check for errors when a symbol gets declared a type twice, even if it
+! is the same.
+
+INTEGER FUNCTION foo ()
+  IMPLICIT NONE
+  INTEGER :: x
+  INTEGER :: x ! { dg-error "basic type of" }
+  x = 42
+END FUNCTION foo