2010-01-13  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/42674
	* c-decl.c (finish_function): Don't emit -Wreturn-type warnings in
	functions with noreturn attribute.

	* decl.c (finish_function): Don't emit -Wreturn-type warnings in
	functions with noreturn attribute.

	* c-c++-common/pr42674.c: New test.

--- gcc/c-decl.c.jj	2010-01-04 10:46:33.000000000 +0100
+++ gcc/c-decl.c	2010-01-13 18:41:44.000000000 +0100
@@ -8032,6 +8032,8 @@ finish_function (void)
       && !current_function_returns_value && !current_function_returns_null
       /* Don't complain if we are no-return.  */
       && !current_function_returns_abnormally
+      /* Don't complain if we are declared noreturn.  */
+      && !TREE_THIS_VOLATILE (fndecl)
       /* Don't warn for main().  */
       && !MAIN_NAME_P (DECL_NAME (fndecl))
       /* Or if they didn't actually specify a return type.  */
--- gcc/cp/decl.c.jj	2009-12-23 17:31:06.000000000 +0100
+++ gcc/cp/decl.c	2010-01-13 18:43:01.000000000 +0100
@@ -12541,6 +12541,8 @@ finish_function (int flags)
       && !current_function_returns_value && !current_function_returns_null
       /* Don't complain if we abort or throw.  */
       && !current_function_returns_abnormally
+      /* Don't complain if we are declared noreturn.  */
+      && !TREE_THIS_VOLATILE (fndecl)
       && !DECL_NAME (DECL_RESULT (fndecl))
       && !TREE_NO_WARNING (fndecl)
       /* Structor return values (if any) are set by the compiler.  */
--- gcc/testsuite/c-c++-common/pr42674.c.jj	2010-01-13 18:57:20.000000000 +0100
+++ gcc/testsuite/c-c++-common/pr42674.c	2010-01-13 18:57:58.000000000 +0100
@@ -0,0 +1,13 @@
+/* PR middle-end/42674 */
+/* { dg-do compile } */
+/* { dg-options "-Wreturn-type" } */
+
+extern void bar (void);
+static int foo (void) __attribute__ ((__noreturn__, __used__));
+
+static int
+foo (void)
+{
+  while (1)
+    bar ();
+}