re PR debug/39379 (DW_TAG_imported* no longer emitted)

	PR debug/39379
	* tree-cfg.c (remove_useless_stmts_bind): Don't remove GIMPLE_BINDs
	with blocks containing IMPORTED_DECLs in BLOCK_VARS.

	* g++.dg/debug/dwarf2/imported-module-3.C: New test.
	* g++.dg/debug/dwarf2/imported-module-4.C: New test.

From-SVN: r144640

gcc/ChangeLog

+2009-03-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/39379
+	* tree-cfg.c (remove_useless_stmts_bind): Don't remove GIMPLE_BINDs
+	with blocks containing IMPORTED_DECLs in BLOCK_VARS.
+
 2009-03-05  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386.md (R8_REG, R9_REG): New constants.

gcc/testsuite/ChangeLog

+2009-03-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/39379
+	* g++.dg/debug/dwarf2/imported-module-3.C: New test.
+	* g++.dg/debug/dwarf2/imported-module-4.C: New test.
+
 2009-03-04  Jason Merrill  <jason@redhat.com>
 
 	PR c++/13549

gcc/testsuite/g++.dg/debug/dwarf2/imported-module-3.C

+// PR debug/39379
+// { dg-do compile }
+// { dg-options "-g -dA" }
+// { dg-final { scan-assembler "DW_TAG_imported" }  }
+
+namespace A
+{
+  int v;
+}
+
+int
+main ()
+{
+  using namespace A;
+  v++;
+  return v - 1;
+}

gcc/testsuite/g++.dg/debug/dwarf2/imported-module-4.C

+// PR debug/39379
+// { dg-do compile }
+// { dg-options "-g -dA" }
+// { dg-final { scan-assembler "DW_TAG_imported" }  }
+
+namespace A
+{
+  int v;
+}
+
+int
+f ()
+{
+  int i;
+  {
+    using namespace A;
+    v++;
+    i = v - 1;
+  }
+  return i;
+}

gcc/tree-cfg.c

@@ -1796,9 +1796,21 @@ remove_useless_stmts_bind (gimple_stmt_iterator *gsi, struct rus_data *data ATTR
 	  || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block))
 	      != FUNCTION_DECL)))
     {
-      gsi_insert_seq_before (gsi, body_seq, GSI_SAME_STMT);
-      gsi_remove (gsi, false);
-      data->repeat = true;
+      tree var = NULL_TREE;
+      /* Even if there are no gimple_bind_vars, there might be other
+	 decls in BLOCK_VARS rendering the GIMPLE_BIND not useless.  */
+      if (block)
+	for (var = BLOCK_VARS (block); var; var = TREE_CHAIN (var))
+	  if (TREE_CODE (var) == IMPORTED_DECL)
+	    break;
+      if (var)
+	gsi_next (gsi);
+      else
+	{
+	  gsi_insert_seq_before (gsi, body_seq, GSI_SAME_STMT);
+	  gsi_remove (gsi, false);
+	  data->repeat = true;
+	}
     }
   else
     gsi_next (gsi);