re PR fortran/49693 (Spurious "unused-variable" warnings for COMMON block module variables.)

2012-01-04  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/49693
	* trans-common.c (create_common): Update copyright years.  Mark
	variables as used to avoid warnings about unused variables in
	common blocks.

2012-01-04  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/49693
	* gfortran.dg/common_17.f90:  New test.

From-SVN: r182869

gcc/fortran/ChangeLog

+2012-01-04  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/49693
+	* trans-common.c (create_common): Update copyright years.  Mark
+	variables as used to avoid warnings about unused variables in
+	common blocks.
+
 2012-01-03  Hans-Peter Nilsson  <hp@axis.com>
 
 	* gfortran.h (struct gfc_expr): Add missing "struct"

gcc/fortran/trans-common.c

 /* Common block and equivalence list handling
-   Copyright (C) 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
+   2011, 2012
    Free Software Foundation, Inc.
    Contributed by Canqun Yang <canqun@nudt.edu.cn>
 
@@ -689,7 +690,9 @@ create_common (gfc_common_head *com, segment_info *head, bool saw_equiv)
 			     VAR_DECL, DECL_NAME (s->field),
 			     TREE_TYPE (s->field));
       TREE_STATIC (var_decl) = TREE_STATIC (decl);
-      TREE_USED (var_decl) = TREE_USED (decl);
+      /* Mark the variable as used in order to avoid warnings about
+	 unused variables.  */
+      TREE_USED (var_decl) = 1;
       if (s->sym->attr.use_assoc)
 	DECL_IGNORED_P (var_decl) = 1;
       if (s->sym->attr.target)

gcc/testsuite/ChangeLog

+2012-01-04  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/49693
+	* gfortran.dg/common_17.f90:  New test.
+
 2012-01-04  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/49651

gcc/testsuite/gfortran.dg/common_17.f90

+! { dg-do compile }
+! { dg-options "-Wall" }
+! PR fortran/49693 - this used to cause a spurious warning for the
+! variable in the common block.
+! Test case by Stephan Kramer.
+module foo
+  implicit none
+  integer:: a, b
+  common a
+end module foo
+! { dg-final { cleanup-modules "foo" } }