Re: Divorce of return warnings

[Jan Hubicka <jh at suse dot cz>]

> 
> > +   if (warn_missing_noreturn
> > +       && !TREE_THIS_VOLATILE (cfun->decl)
> > +       && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
> > +       && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl))
> > +     warning (0, "%Jfunction might be possible candidate for "
> 
> Could we get in the habit of moving the warn_* into warning(OPT_W* as
> we encounter these?  Or at least adding the OPT_W* when the warn_*
> test bypasses expensive checks?  Please?  ;-)
OK, here is updated patch I am testing.
OK?

Index: tree-cfg.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-cfg.c,v
retrieving revision 2.188
diff -c -3 -p -r2.188 tree-cfg.c
*** tree-cfg.c	13 May 2005 13:56:49 -0000	2.188
--- tree-cfg.c	13 May 2005 19:45:01 -0000
*************** Boston, MA 02111-1307, USA.  */
*** 45,50 ****
--- 45,51 ----
  #include "cfgloop.h"
  #include "cfglayout.h"
  #include "hashtab.h"
+ #include "options.h"
  
  /* This file contains functions for building the Control Flow Graph (CFG)
     for a function tree.  */
*************** execute_warn_function_return (void)
*** 5630,5643 ****
    edge e;
    edge_iterator ei;
  
-   if (warn_missing_noreturn
-       && !TREE_THIS_VOLATILE (cfun->decl)
-       && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
-       && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl))
-     warning (0, "%Jfunction might be possible candidate for "
- 	     "attribute %<noreturn%>",
- 	     cfun->decl);
- 
    /* If we have a path to EXIT, then we do return.  */
    if (TREE_THIS_VOLATILE (cfun->decl)
        && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0)
--- 5631,5636 ----
*************** struct tree_opt_pass pass_warn_function_
*** 5741,5743 ****
--- 5734,5772 ----
    0,					/* todo_flags_finish */
    0					/* letter */
  };
+ 
+ /* Emit noreturn warnings.  */
+ 
+ static void
+ execute_warn_function_noreturn (void)
+ {
+   if (!TREE_THIS_VOLATILE (cfun->decl)
+       && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0
+       && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl))
+     warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate for "
+ 	     "attribute %<noreturn%>",
+ 	     cfun->decl);
+ }
+ 
+ static bool
+ gate_warn_function_noreturn (void)
+ {
+   return warn_missing_noreturn;
+ }
+ 
+ struct tree_opt_pass pass_warn_function_noreturn =
+ {
+   NULL,					/* name */
+   gate_warn_function_noreturn,		/* gate */
+   execute_warn_function_noreturn,	/* execute */
+   NULL,					/* sub */
+   NULL,					/* next */
+   0,					/* static_pass_number */
+   0,					/* tv_id */
+   PROP_cfg,				/* properties_required */
+   0,					/* properties_provided */
+   0,					/* properties_destroyed */
+   0,					/* todo_flags_start */
+   0,					/* todo_flags_finish */
+   0					/* letter */
+ };
Index: tree-optimize.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-optimize.c,v
retrieving revision 2.92
diff -c -3 -p -r2.92 tree-optimize.c
*** tree-optimize.c	13 May 2005 13:56:57 -0000	2.92
--- tree-optimize.c	13 May 2005 19:45:01 -0000
*************** init_tree_optimization_passes (void)
*** 327,336 ****
    NEXT_PASS (pass_lower_eh);
    NEXT_PASS (pass_build_cfg);
    NEXT_PASS (pass_pre_expand);
    NEXT_PASS (pass_tree_profile);
    NEXT_PASS (pass_init_datastructures);
    NEXT_PASS (pass_all_optimizations);
!   NEXT_PASS (pass_warn_function_return);
    NEXT_PASS (pass_mudflap_2);
    NEXT_PASS (pass_free_datastructures);
    NEXT_PASS (pass_expand);
--- 327,337 ----
    NEXT_PASS (pass_lower_eh);
    NEXT_PASS (pass_build_cfg);
    NEXT_PASS (pass_pre_expand);
+   NEXT_PASS (pass_warn_function_return);
    NEXT_PASS (pass_tree_profile);
    NEXT_PASS (pass_init_datastructures);
    NEXT_PASS (pass_all_optimizations);
!   NEXT_PASS (pass_warn_function_noreturn);
    NEXT_PASS (pass_mudflap_2);
    NEXT_PASS (pass_free_datastructures);
    NEXT_PASS (pass_expand);
Index: tree-pass.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-pass.h,v
retrieving revision 2.33
diff -c -3 -p -r2.33 tree-pass.h
*** tree-pass.h	21 Apr 2005 13:18:23 -0000	2.33
--- tree-pass.h	13 May 2005 19:45:01 -0000
*************** extern struct tree_opt_pass pass_stdarg;
*** 197,202 ****
--- 197,203 ----
  extern struct tree_opt_pass pass_early_warn_uninitialized;
  extern struct tree_opt_pass pass_late_warn_uninitialized;
  extern struct tree_opt_pass pass_warn_function_return;
+ extern struct tree_opt_pass pass_warn_function_noreturn;
  extern struct tree_opt_pass pass_phiopt;
  extern struct tree_opt_pass pass_forwprop;
  extern struct tree_opt_pass pass_redundant_phi;