* c-decl.c (warn_missing_noreturn): Remove.

        (c_expand_body): Don't set or check can_reach_end.
        * c-tree.h (warn_missing_noreturn): Move ...
        * flags.h: ... here.
        (can_reach_end): Remove.
        * flow.c (check_function_return_warnings): New.
        (make_edges): No edge to exit for noreturn sibcalls.
        * function.c (expand_function_end): Save the return value
        clobber instruction.
        (mark_function_status): Mark it.
        * function.h (struct function): Add x_clobber_return_insn.
        * jump.c (can_reach_end): Remove.
        (calculate_can_reach_end): Remove.
        (jump_optimize_1): Don't call it.
        * output.h (check_function_return_warnings): Declare.
        * toplev.c (warn_missing_noreturn): Move from c-decl.c
        (rest_of_compilation): Call check_function_return_warnings.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@36750 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 9 insertions, 0 deletions

diff --git a/gcc/function.c b/gcc/function.c
index f5814109211..85a18bf0b87 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -6658,12 +6658,20 @@ expand_function_end (filename, line, end_bindings)
 
   if (return_label)
     {
+      rtx before, after;
+
       /* Before the return label, clobber the return registers so that
          they are not propogated live to the rest of the function.  This
 	 can only happen with functions that drop through; if there had
 	 been a return statement, there would have either been a return
 	 rtx, or a jump to the return label.  */
+
+      before = get_last_insn ();
       clobber_return_register ();
+      after = get_last_insn ();
+
+      if (before != after)
+	cfun->x_clobber_return_insn = after;
 
       emit_label (return_label);
     }
@@ -7429,6 +7437,7 @@ mark_function_status (p)
   ggc_mark_tree (p->x_context_display);
   ggc_mark_tree (p->x_trampoline_list);
   ggc_mark_rtx (p->epilogue_delay_list);
+  ggc_mark_rtx (p->x_clobber_return_insn);
 
   mark_temp_slot (p->x_temp_slots);