re PR fortran/55352 (Erroneous gfortran warning of unused module variable when variable is only used in namelist)

2012-11-21  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/55352
	* trans-decl.c (generate_local_decl): Don't warn for explicitly imported
	but unused module variables which are in a namelist or common block.

2012-11-21  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/55352
	* gfortran.dg/namelist_76.f90: New.

From-SVN: r193711

4 files changed, 56 insertions, 14 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index d53bf1a..3b5b27c 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,9 @@
+2012-11-21  Janus Weil  <janus@gcc.gnu.org>
+
+	PR fortran/55352
+	* trans-decl.c (generate_local_decl): Don't warn for explicitly imported
+	but unused module variables which are in a namelist or common block.
+
 2012-11-20  Diego Novillo  <dnovillo@google.com>
 	    Jakub Jelinek  <jakub@redhat.com>
 
diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index c661fb3..6827298 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -4589,22 +4589,25 @@ generate_local_decl (gfc_symbol * sym)
 	}
 
       /* Warn for unused variables, but not if they're inside a common
-	 block, a namelist, or are use-associated.  */
+	 block or a namelist.  */
       else if (warn_unused_variable
-	       && !(sym->attr.in_common || sym->attr.use_assoc || sym->mark
-		    || sym->attr.in_namelist))
+	       && !(sym->attr.in_common || sym->mark || sym->attr.in_namelist))
 	{
-	  gfc_warning ("Unused variable '%s' declared at %L", sym->name,
-		       &sym->declared_at);
-	  if (sym->backend_decl != NULL_TREE)
-	    TREE_NO_WARNING(sym->backend_decl) = 1;
-	}
-      else if (warn_unused_variable && sym->attr.use_only)
-	{
-	  gfc_warning ("Unused module variable '%s' which has been explicitly "
-		       "imported at %L", sym->name, &sym->declared_at);
-	  if (sym->backend_decl != NULL_TREE)
-	    TREE_NO_WARNING(sym->backend_decl) = 1;
+	  if (sym->attr.use_only)
+	    {
+	      gfc_warning ("Unused module variable '%s' which has been "
+			   "explicitly imported at %L", sym->name,
+			   &sym->declared_at);
+	      if (sym->backend_decl != NULL_TREE)
+		TREE_NO_WARNING(sym->backend_decl) = 1;
+	    }
+	  else if (!sym->attr.use_assoc)
+	    {
+	      gfc_warning ("Unused variable '%s' declared at %L",
+			   sym->name, &sym->declared_at);
+	      if (sym->backend_decl != NULL_TREE)
+		TREE_NO_WARNING(sym->backend_decl) = 1;
+	    }
 	}
 
       /* For variable length CHARACTER parameters, the PARM_DECL already
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3a12c81..cb52cdc 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-11-21  Janus Weil  <janus@gcc.gnu.org>
+
+	PR fortran/55352
+	* gfortran.dg/namelist_76.f90: New.
+
 2012-11-21  Martin Jambor  <mjambor@suse.cz>
 
 	* gcc.dg/ipa/ipcp-agg-7.c: New test.
diff --git a/gcc/testsuite/gfortran.dg/namelist_76.f90 b/gcc/testsuite/gfortran.dg/namelist_76.f90
new file mode 100644
index 0000000..acb3b2f
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/namelist_76.f90
@@ -0,0 +1,28 @@
+! { dg-do compile }
+!
+! PR 55352: [4.7/4.8 Regression] Erroneous gfortran warning of unused module variable when variable is only used in namelist
+!
+! Contributed by <AstroFloyd@gmail.com>
+
+module data
+  implicit none
+  integer :: a
+end module data
+
+program test
+  use data, only: a
+  implicit none
+  a = 1
+  call write_data()
+end program test
+
+subroutine write_data()
+  use data, only: a
+  implicit none
+  namelist /write_data_list/ a
+  open(unit=10,form='formatted',status='replace',action='write',file='test.dat')
+  write(10, nml=write_data_list)
+  close(10)
+end subroutine write_data
+
+! { dg-final { cleanup-modules "data" } }