[patch][plugin] Add PLUGIN_START_UNIT

[Olatunji Ruwase <tjruwase at google dot com>]

Hello,
 This patch adds PLUGIN_START_UNIT callbacks.

 PLUGIN_START_UNIT callbacks allow plugins to initialize state for
each translation unit, before it is compiled.
 For example, plugins like mudflap create artificial variables/types
and expect type trees (*_type_node) have been created.
 Therefore PLUGIN_START_UNIT callbacks are invoked after all the
frontend initialization but before code compilation.

 The patch bootstraps on x86_64-unknown-linux-gnu target and has no
test suite regressions.
 Thank you

tunji



2009-06-22  Olatunji Ruwase   <tjruwase@google.com>

        * doc/plugins.texi: Document PLUGIN_START_UNIT.
        * toplev.c (compile_file): Call PLUGIN_START_UNIT.
        * gcc-plugin.h (PLUGIN_START_UNIT): Added new event.
        * plugin.c (plugin_event_name): Added PLUGIN_START_UNIT.
          (register_callback): Handle PLUGIN_START_UNIT.
          (invoke_plugin_callbacks): Handle PLUGIN_START_UNIT.

Index: gcc/doc/plugins.texi
===================================================================
--- gcc/doc/plugins.texi        (revision 148809)
+++ gcc/doc/plugins.texi        (working copy)
@@ -134,6 +134,7 @@ enum plugin_event
   PLUGIN_GGC_END,              /* Called at end of GGC. */
   PLUGIN_REGISTER_GGC_ROOTS,   /* Register an extra GGC root table. */
   PLUGIN_ATTRIBUTES,            /* Called during attribute registration */
+  PLUGIN_START_UNIT,            /* Called before processing a
translation unit.  */
   PLUGIN_EVENT_LAST             /* Dummy event used for indexing callback
                                                     array.  */
 @};
Index: gcc/toplev.c
===================================================================
--- gcc/toplev.c        (revision 148809)
+++ gcc/toplev.c        (working copy)
@@ -1017,6 +1017,7 @@ compile_file (void)
   init_final (main_input_filename);
   coverage_init (aux_base_name);
   statistics_init ();
+  invoke_plugin_callbacks (PLUGIN_START_UNIT, NULL);

   timevar_push (TV_PARSE);


   /* Stop timing and print the times.  */
Index: gcc/gcc-plugin.h
===================================================================
--- gcc/gcc-plugin.h    (revision 148809)
+++ gcc/gcc-plugin.h    (working copy)
@@ -41,6 +41,7 @@ enum plugin_event
   PLUGIN_GGC_END,              /* Called at end of GGC. */
   PLUGIN_REGISTER_GGC_ROOTS,   /* Register an extra GGC root table. */
   PLUGIN_ATTRIBUTES,            /* Called during attribute registration.  */
+  PLUGIN_START_UNIT,            /* Called before processing a
translation unit.  */
   PLUGIN_EVENT_LAST             /* Dummy event used for indexing callback
                                                     array.  */
 };
Index: gcc/plugin.c
===================================================================
--- gcc/plugin.c        (revision 148809)
+++ gcc/plugin.c        (working copy)
@@ -57,6 +57,7 @@ const char *plugin_event_name[] =
   "PLUGIN_GGC_MARKING",
   "PLUGIN_GGC_END",
   "PLUGIN_REGISTER_GGC_ROOTS",
+  "PLUGIN_START_UNIT",
   "PLUGIN_EVENT_LAST"
 };

@@ -499,6 +500,7 @@ register_callback (const char *plugin_na
         ggc_register_root_tab ((const struct ggc_root_tab*) user_data);
        break;
       case PLUGIN_FINISH_TYPE:
+      case PLUGIN_START_UNIT:
       case PLUGIN_FINISH_UNIT:
       case PLUGIN_CXX_CP_PRE_GENERICIZE:
       case PLUGIN_GGC_START:
@@ -544,6 +546,7 @@ invoke_plugin_callbacks (enum plugin_eve
   switch (event)
     {
       case PLUGIN_FINISH_TYPE:
+      case PLUGIN_START_UNIT:
       case PLUGIN_FINISH_UNIT:
       case PLUGIN_CXX_CP_PRE_GENERICIZE:
       case PLUGIN_ATTRIBUTES: