re PR rtl-optimization/13394 (noreturn attribute ignored on recursive invokation)

	PR optimization/13394
	* toplev.c (rest_of_compilation): Move call to
	check_function_return_warnings right after the sibcall
	optimization pass.

From-SVN: r74961

4 files changed, 61 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 81b80df..f87dbac 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,12 @@
 2003-12-23  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
+	PR optimization/13394
+	* toplev.c (rest_of_compilation): Move call to
+	check_function_return_warnings right after the sibcall
+	optimization pass.
+
+2003-12-23  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
 	PR c/13382
 	* c-typeck.c (convert_for_assignment): When converting from
 	integral type to pointer type, always call convert.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index bf06bea..9095c8a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,9 @@
 2003-12-23  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
+	* gcc.dg/noreturn-7.c: New test.
+
+2003-12-23  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
 	* gcc.dg/null-pointer-1.c: New test.
 
 2003-12-22  Mark Mitchell  <mark@codesourcery.com>
diff --git a/gcc/testsuite/gcc.dg/noreturn-7.c b/gcc/testsuite/gcc.dg/noreturn-7.c
new file mode 100644
index 0000000..1d94a7c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/noreturn-7.c
@@ -0,0 +1,42 @@
+/* PR optimization/13394 */
+/* Origin: Carlo Wood <carlo@gcc.gnu.org> */
+
+/* Verify that a bogus "function does return" warning is not issued
+   in presence of tail recursion within a noreturn function.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wreturn-type -Wmissing-noreturn" } */
+
+
+void f(void) __attribute__ ((__noreturn__));
+void _exit(int status) __attribute__ ((__noreturn__));
+
+int z = 0;
+
+void g()
+{
+  if (++z > 10)
+    _exit(0);
+  g();
+}             /* { dg-warning "possible candidate" } */
+
+void f()
+{
+  if (++z > 10)
+    _exit(0);
+  f();
+}             /* { dg-bogus "does return" } */
+
+int h()
+{
+  if (++z > 10)
+    _exit(0);
+  return h();
+}             /* { dg-bogus "end of non-void function" } */
+
+int k()
+{
+  if (++z > 10)
+    _exit(0);
+  k();
+}             /* { dg-warning "end of non-void function" } */
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 2ed4c31..7d01eb6 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -3144,10 +3144,6 @@ rest_of_compilation (tree decl)
 
   delete_unreachable_blocks ();
 
-  /* We have to issue these warnings now already, because CFG cleanups
-     further down may destroy the required information.  */
-  check_function_return_warnings ();
-
   /* Turn NOTE_INSN_PREDICTIONs into branch predictions.  */
   if (flag_guess_branch_prob)
     {
@@ -3159,6 +3155,14 @@ rest_of_compilation (tree decl)
   if (flag_optimize_sibling_calls)
     rest_of_handle_sibling_calls (insns);
 
+  /* We have to issue these warnings now already, because CFG cleanups
+     further down may destroy the required information.  However, this
+     must be done after the sibcall optimization pass because the barrier
+     emitted for noreturn calls that are candidate for the optimization
+     is folded into the CALL_PLACEHOLDER until after this pass, so the
+     CFG is inaccurate.  */
+  check_function_return_warnings ();
+
   timevar_pop (TV_JUMP);
 
   insn_locators_initialize ();