re PR debug/42234 (internal compiler error: verify_ssa failed)

	PR c++/42234
	* tree-cfgcleanup.c (cleanup_omp_return): Don't ICE if control_bb
	contains no statements.

	* g++.dg/gomp/pr42234.C: New test.

From-SVN: r154878

gcc/ChangeLog

+2009-12-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/42234
+	* tree-cfgcleanup.c (cleanup_omp_return): Don't ICE if control_bb
+	contains no statements.
+
 2009-12-01  Grigori Fursin  <grigori.fursin@inria.fr>
 	    Joern Rennecke  <amylaar@spamcop.net>
 

gcc/testsuite/ChangeLog

+2009-12-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/42234
+	* g++.dg/gomp/pr42234.C: New test.
+
 2009-12-01  Martin Jambor  <mjambor@suse.cz>
 
 	PR tree-optimization/42237

gcc/testsuite/g++.dg/gomp/pr42234.C

+// PR c++/42234
+// { dg-do compile }
+// { dg-options "-fopenmp" }
+
+extern int foo (void);
+
+void
+bar (int x)
+{
+  #pragma omp critical
+    {
+      int j;
+      for (j = 0; j < foo (); j++)
+	;
+      if (0)
+        if (x >= 4)
+	  ;
+    }
+}

gcc/tree-cfgcleanup.c

 /* CFG cleanup for trees.
-   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -511,7 +511,7 @@ cleanup_omp_return (basic_block bb)
   control_bb = single_pred (bb);
   stmt = last_stmt (control_bb);
 
-  if (gimple_code (stmt) != GIMPLE_OMP_SECTIONS_SWITCH)
+  if (stmt == NULL || gimple_code (stmt) != GIMPLE_OMP_SECTIONS_SWITCH)
     return false;
 
   /* The block with the control statement normally has two entry edges -- one