RFA: hookize OVERRIDE_OPTIONS

Index: doc/tm.texi
===================================================================
--- doc/tm.texi	(revision 161394)
+++ doc/tm.texi	(working copy)
@@ -793,15 +793,18 @@  Don't use this macro to turn on various 
 If you need to do something whenever the optimization level is
 changed via the optimize attribute or pragma, see
 @code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}
+
+This macros is obsolete, new ports should use the target hook
+@code{TARGET_OPTION_OVERRIDE} instead.
 @end defmac
 
 @deftypefn {Target Hook} void TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE (void)
-This target function is similar to the macro @code{OVERRIDE_OPTIONS}
+This target function is similar to the hook @code{TARGET_OPTION_OVERRIDE}
 but is called when the optimize level is changed via an attribute or
 pragma or when it is reset at the end of the code affected by the
 attribute or pragma.  It is not called at the beginning of compilation
-when @code{OVERRIDE_OPTIONS} is called so if you want to perform these
-actions then, you should have @code{OVERRIDE_OPTIONS} call
+when @code{TARGET_OPTION_OVERRIDE} is called so if you want to perform these
+actions then, you should have @code{TARGET_OPTION_OVERRIDE} call
 @code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}.
 @end deftypefn
 
@@ -8823,7 +8826,7 @@  define the macro.
 
 Unless it's necessary to inspect the @var{label} parameter, it is better
 to set the variable @var{align_jumps} in the target's
-@code{OVERRIDE_OPTIONS}.  Otherwise, you should try to honor the user's
+@code{TARGET_OPTION_OVERRIDE}.  Otherwise, you should try to honor the user's
 selection in @var{align_jumps} in a @code{JUMP_ALIGN} implementation.
 @end defmac
 
@@ -8852,7 +8855,7 @@  define the macro.
 
 Unless it's necessary to inspect the @var{label} parameter, it is better
 to set the variable @code{align_loops} in the target's
-@code{OVERRIDE_OPTIONS}.  Otherwise, you should try to honor the user's
+@code{TARGET_OPTION_OVERRIDE}.  Otherwise, you should try to honor the user's
 selection in @code{align_loops} in a @code{LOOP_ALIGN} implementation.
 @end defmac
 
@@ -8868,7 +8871,7 @@  the maximum of the specified values is u
 
 Unless it's necessary to inspect the @var{label} parameter, it is better
 to set the variable @code{align_labels} in the target's
-@code{OVERRIDE_OPTIONS}.  Otherwise, you should try to honor the user's
+@code{TARGET_OPTION_OVERRIDE}.  Otherwise, you should try to honor the user's
 selection in @code{align_labels} in a @code{LABEL_ALIGN} implementation.
 @end defmac
 
@@ -9340,7 +9343,7 @@  in response to the @option{-g} option.  
 is to generate minimal debug info for a traceback in the absence of
 @option{-g} unless explicitly overridden with @option{-g0}.  This
 behavior is controlled by @code{OPTIMIZATION_OPTIONS} and
-@code{OVERRIDE_OPTIONS}.
+@code{TARGET_OPTION_OVERRIDE}.
 @end defmac
 
 @node Floating Point
@@ -9682,6 +9685,20 @@  input stream.  The options should be the
 @code{TARGET_VALID_OPTION_ATTRIBUTE_P} hook.
 @end deftypefn
 
+@deftypefn {Target Hook} void TARGET_OPTION_OVERRIDE (void)
+Sometimes certain combinations of command options do not make sense on
+a particular target machine.  You can override the hook
+@code{TARGET_OPTION_OVERRIDE} to take account of this.  This hooks is called
+once just after all the command options have been parsed.
+
+Don't use this hook to turn on various extra optimizations for
+@option{-O}.  That is what @code{OPTIMIZATION_OPTIONS} is for.
+
+If you need to do something whenever the optimization level is
+changed via the optimize attribute or pragma, see
+@code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}
+@end deftypefn
+
 @deftypefn {Target Hook} bool TARGET_CAN_INLINE_P (tree @var{caller}, tree @var{callee})
 This target hook returns @code{false} if the @var{caller} function
 cannot inline @var{callee}, based on target specific information.  By
Index: targhooks.c
===================================================================
--- targhooks.c	(revision 161394)
+++ targhooks.c	(working copy)
@@ -859,6 +859,14 @@  default_secondary_reload (bool in_p ATTR
   return rclass;
 }
 
+void
+default_target_option_override (void)
+{
+#ifdef OVERRIDE_OPTIONS
+  OVERRIDE_OPTIONS;
+#endif
+}
+
 bool
 default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
 			 const char *arg ATTRIBUTE_UNUSED,
Index: targhooks.h
===================================================================
--- targhooks.h	(revision 161394)
+++ targhooks.h	(working copy)
@@ -115,6 +115,7 @@  extern const enum reg_class *default_ira
 extern enum reg_class default_secondary_reload (bool, rtx, enum reg_class,
 						enum machine_mode,
 						secondary_reload_info *);
+extern void default_target_option_override (void);
 extern void hook_void_bitmap (bitmap);
 extern bool default_handle_c_option (size_t, const char *, int);
 extern int default_reloc_rw_mask (void);
Index: target.h
===================================================================
--- target.h	(revision 161394)
+++ target.h	(working copy)
@@ -1234,6 +1234,9 @@  struct gcc_target
        true if the options are valid, and set the current state.  */
     bool (*pragma_parse) (tree, tree);
 
+     /* Do option overrides for the target.  */
+     void (*override) (void);
+
     /* Function to determine if one function can inline another function.  */
     bool (*can_inline_p) (tree, tree);
   } target_option;
Index: toplev.c
===================================================================
--- toplev.c	(revision 161394)
+++ toplev.c	(working copy)
@@ -1761,10 +1761,8 @@  process_options (void)
      so we can correctly initialize debug output.  */
   no_backend = lang_hooks.post_options (&main_input_filename);
 
-#ifdef OVERRIDE_OPTIONS
   /* Some machines may reject certain combinations of options.  */
-  OVERRIDE_OPTIONS;
-#endif
+  targetm.target_option.override ();
 
   /* Avoid any informative notes in the second run of -fcompare-debug.  */
   if (flag_compare_debug) 
Index: target-def.h
===================================================================
--- target-def.h	(revision 161394)
+++ target-def.h	(working copy)
@@ -946,6 +946,10 @@ 
 #define TARGET_OPTION_PRAGMA_PARSE default_target_option_pragma_parse
 #endif
 
+#ifndef TARGET_OPTION_OVERRIDE
+#define TARGET_OPTION_OVERRIDE default_target_option_override
+#endif
+
 #ifndef TARGET_CAN_INLINE_P
 #define TARGET_CAN_INLINE_P default_target_can_inline_p
 #endif
@@ -957,6 +961,7 @@ 
     TARGET_OPTION_RESTORE,			\
     TARGET_OPTION_PRINT,			\
     TARGET_OPTION_PRAGMA_PARSE,			\
+    TARGET_OPTION_OVERRIDE,			\
     TARGET_CAN_INLINE_P,			\
   }