diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1aa0e5e01d6..e87e0d4f091 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2012-08-06  Cary Coutant  <ccoutant@google.com>
+
+	* cgraphunit.c (assemble_thunk): Add source line info.
+	* final.c (final): Check for non-null cfg pointer.
+
 2012-08-06  Sandra Loosemore  <sandra@codesourcery.com>
 	    Maxim Kuvyrkov  <maxim@codesourcery.com>
 	    Julian Brown  <julian@codesourcery.com>
diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index a6591b5c133..2dd0871e736 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -1381,6 +1381,10 @@ assemble_thunk (struct cgraph_node *node)
       init_function_start (thunk_fndecl);
       cfun->is_thunk = 1;
       assemble_start_function (thunk_fndecl, fnname);
+      (*debug_hooks->source_line) (DECL_SOURCE_LINE (thunk_fndecl),
+				   DECL_SOURCE_FILE (thunk_fndecl),
+				   /* discriminator */ 0,
+				   /* is_stmt */ 1);
 
       targetm.asm_out.output_mi_thunk (asm_out_file, thunk_fndecl,
 				       fixed_offset, virtual_value, alias);
diff --git a/gcc/final.c b/gcc/final.c
index cdae0117388..30890b3ce22 100644
--- a/gcc/final.c
+++ b/gcc/final.c
@@ -1863,11 +1863,13 @@ final (rtx first, FILE *file, int optimize_p)
       start_to_bb = XCNEWVEC (basic_block, bb_map_size);
       end_to_bb = XCNEWVEC (basic_block, bb_map_size);
 
-      FOR_EACH_BB_REVERSE (bb)
-	{
-	  start_to_bb[INSN_UID (BB_HEAD (bb))] = bb;
-	  end_to_bb[INSN_UID (BB_END (bb))] = bb;
-	}
+      /* There is no cfg for a thunk.  */
+      if (!cfun->is_thunk)
+	FOR_EACH_BB_REVERSE (bb)
+	  {
+	    start_to_bb[INSN_UID (BB_HEAD (bb))] = bb;
+	    end_to_bb[INSN_UID (BB_END (bb))] = bb;
+	  }
     }
 
   /* Output the insns.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 89a6917ce47..5eeb52629eb 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2012-08-06  Cary Coutant  <ccoutant@google.com>
+
+	* g++.dg/debug/dwarf2/non-virtual-thunk.C: New test case.
+
 2012-08-06  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/35831
diff --git a/gcc/testsuite/g++.dg/debug/dwarf2/non-virtual-thunk.C b/gcc/testsuite/g++.dg/debug/dwarf2/non-virtual-thunk.C
new file mode 100644
index 00000000000..8ad347a7cc3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/debug/dwarf2/non-virtual-thunk.C
@@ -0,0 +1,39 @@
+// { dg-do compile }
+// { dg-options "-g2 -dA" }
+
+// Verify that line number info is output for the non-virtual
+// thunks for C::~C().
+// { dg-final { scan-assembler "thunk.C:30" } }
+
+class A
+{
+ public:
+  A();
+  virtual ~A();
+ private:
+  int i;
+};
+
+class B
+{
+ public:
+  B();
+  virtual ~B();
+ private:
+  int i;
+};
+
+class C : public A, public B
+{
+ public:
+  C();
+  virtual ~C(); // line 30
+};
+
+C::C()
+{
+}
+
+C::~C()
+{
+}