Add support for using ggc cache tables from plugins.

Approved by Ian Lance Taylor.

From-SVN: r152232

gcc/ChangeLog

+2009-09-27  Duncan Sands  <baldrick@free.fr>
+
+	* gcc-plugin.h (PLUGIN_REGISTER_GGC_CACHES): New event.
+	* plugin.c (plugin_event_name): Add PLUGIN_REGISTER_GGC_CACHES.
+	(register_callback): Dispatch it.
+	(invoke_plugin_callbacks): Incorporate in sanity check.
+	* ggc.h (ggc_register_cache_tab): Add declaration.
+	* ggc-common.c (ggc_register_root_tab): Simplify.
+	(const_ggc_cache_tab_t): New typedef.
+	(extra_cache_vec): New vector of dynamically added cache tables.
+	(ggc_register_cache_tab): New function.
+	(ggc_scan_cache_tab): New function.
+	(ggc_mark_roots): Simplify dynamic roots.  Handle dynamic caches.
+	* doc/plugins.texi: Document PLUGIN_REGISTER_GGC_CACHES.
+
 2009-09-27  Richard Henderson  <rth@redhat.com>
 
 	* tree-ssa-ccp.c (optimize_stack_restore): Relax the conditions under

gcc/doc/plugins.texi

@@ -133,6 +133,7 @@ enum plugin_event
   PLUGIN_GGC_MARKING,		/* Extend the GGC marking. */
   PLUGIN_GGC_END,		/* Called at end of GGC. */
   PLUGIN_REGISTER_GGC_ROOTS,	/* Register an extra GGC root table. */
+  PLUGIN_REGISTER_GGC_CACHES,	/* Register an extra GGC cache 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
@@ -151,8 +152,8 @@ the arguments:
 @item @code{void *user_data}: Pointer to plugin-specific data.
 @end itemize
 
-For the PLUGIN_PASS_MANAGER_SETUP, PLUGIN_INFO, and
-PLUGIN_REGISTER_GGC_ROOTS pseudo-events the @code{callback} should be
+For the PLUGIN_PASS_MANAGER_SETUP, PLUGIN_INFO, PLUGIN_REGISTER_GGC_ROOTS
+and PLUGIN_REGISTER_GGC_CACHES pseudo-events the @code{callback} should be
 null, and the @code{user_data} is specific.
 
 @section Interacting with the pass manager
@@ -222,16 +223,19 @@ for the @code{PLUGIN_GGC_MARKING} event. Such callbacks can call the
 (and conversely, these routines should usually not be used in plugins
 outside of the @code{PLUGIN_GGC_MARKING} event).  
 
-Some plugins may need to add extra GGC root tables, e.g. to handle
-their own @code{GTY}-ed data. This can be done with the
-@code{PLUGIN_REGISTER_GGC_ROOTS} pseudo-event with a null callback and
-the extra root table as @code{user_data}.  Running the @code{gengtype
--p @var{source-dir} @var{file-list} @var{plugin*.c} ...} utility
-generates this extra root table.
+Some plugins may need to add extra GGC root tables, e.g. to handle their own
+@code{GTY}-ed data. This can be done with the @code{PLUGIN_REGISTER_GGC_ROOTS}
+pseudo-event with a null callback and the extra root table (of type @code{struct
+ggc_root_tab*}) as @code{user_data}.  Plugins that want to use the
+@code{if_marked} hash table option can add the extra GGC cache tables generated
+by @code{gengtype} using the @code{PLUGIN_REGISTER_GGC_CACHES} pseudo-event with
+a null callback and the extra cache table (of type @code{struct ggc_cache_tab*})
+as @code{user_data}.  Running the @code{gengtype -p @var{source-dir}
+@var{file-list} @var{plugin*.c} ...} utility generates these extra root tables.
 
 You should understand the details of memory management inside GCC
-before using @code{PLUGIN_GGC_MARKING} or
-@code{PLUGIN_REGISTER_GGC_ROOTS}.
+before using @code{PLUGIN_GGC_MARKING}, @code{PLUGIN_REGISTER_GGC_ROOTS}
+or @code{PLUGIN_REGISTER_GGC_CACHES}.
 
 
 @section Giving information about a plugin

gcc/gcc-plugin.h

@@ -40,6 +40,7 @@ enum plugin_event
   PLUGIN_GGC_MARKING,		/* Extend the GGC marking. */
   PLUGIN_GGC_END,		/* Called at end of GGC. */
   PLUGIN_REGISTER_GGC_ROOTS,	/* Register an extra GGC root table. */
+  PLUGIN_REGISTER_GGC_CACHES,	/* Register an extra GGC cache 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
@@ -144,8 +145,8 @@ typedef void (*plugin_callback_func) (void *gcc_data, void *user_data);
 */
 
 /* This is also called without a callback routine for the
-   PLUGIN_PASS_MANAGER_SETUP, PLUGIN_INFO, PLUGIN_REGISTER_GGC_ROOTS
-   pseudo-events, with a specific user_data.
+   PLUGIN_PASS_MANAGER_SETUP, PLUGIN_INFO, PLUGIN_REGISTER_GGC_ROOTS and
+   PLUGIN_REGISTER_GGC_CACHES pseudo-events, with a specific user_data.
   */
 
 extern void register_callback (const char *plugin_name,

gcc/ggc-common.c

@@ -91,30 +91,59 @@ ggc_htab_delete (void **slot, void *info)
 
 /* This extra vector of dynamically registered root_tab-s is used by
    ggc_mark_roots and gives the ability to dynamically add new GGC root
-   tables, for instance from some plugins; this vector is a heap one
-   [since it is used by GGC internally!] */
-typedef const struct ggc_root_tab* const_ggc_root_tab_t;
+   tables, for instance from some plugins; this vector is on the heap
+   since it is used by GGC internally.  */
+typedef const struct ggc_root_tab *const_ggc_root_tab_t;
 DEF_VEC_P(const_ggc_root_tab_t);
 DEF_VEC_ALLOC_P(const_ggc_root_tab_t, heap);
 static VEC(const_ggc_root_tab_t, heap) *extra_root_vec;
 
-
 /* Dynamically register a new GGC root table RT. This is useful for
    plugins. */
 
 void 
 ggc_register_root_tab (const struct ggc_root_tab* rt)
 {
-  if (!rt)
-    return;
-  if (!extra_root_vec) 
-    {
-      int vlen = 32;
-      extra_root_vec = VEC_alloc (const_ggc_root_tab_t, heap, vlen);
-    }
-  VEC_safe_push (const_ggc_root_tab_t, heap, extra_root_vec, rt);
+  if (rt)
+    VEC_safe_push (const_ggc_root_tab_t, heap, extra_root_vec, rt);
+}
+
+/* This extra vector of dynamically registered cache_tab-s is used by
+   ggc_mark_roots and gives the ability to dynamically add new GGC cache
+   tables, for instance from some plugins; this vector is on the heap
+   since it is used by GGC internally.  */
+typedef const struct ggc_cache_tab *const_ggc_cache_tab_t;
+DEF_VEC_P(const_ggc_cache_tab_t);
+DEF_VEC_ALLOC_P(const_ggc_cache_tab_t, heap);
+static VEC(const_ggc_cache_tab_t, heap) *extra_cache_vec;
+
+/* Dynamically register a new GGC cache table CT. This is useful for
+   plugins. */
+
+void
+ggc_register_cache_tab (const struct ggc_cache_tab* ct)
+{
+  if (ct)
+    VEC_safe_push (const_ggc_cache_tab_t, heap, extra_cache_vec, ct);
 }
 
+/* Scan a hash table that has objects which are to be deleted if they are not
+   already marked.  */
+
+static void
+ggc_scan_cache_tab (const_ggc_cache_tab_t ctp)
+{
+  const struct ggc_cache_tab *cti;
+
+  for (cti = ctp; cti->base != NULL; cti++)
+    if (*cti->base)
+      {
+        ggc_set_mark (*cti->base);
+        htab_traverse_noresize (*cti->base, ggc_htab_delete,
+                                CONST_CAST (void *, (const void *)cti));
+        ggc_set_mark ((*cti->base)->entries);
+      }
+}
 
 /* Iterate through all registered roots and mark each element.  */
 
@@ -123,8 +152,9 @@ ggc_mark_roots (void)
 {
   const struct ggc_root_tab *const *rt;
   const struct ggc_root_tab *rti;
+  const_ggc_root_tab_t rtp;
   const struct ggc_cache_tab *const *ct;
-  const struct ggc_cache_tab *cti;
+  const_ggc_cache_tab_t ctp;
   size_t i;
 
   for (rt = gt_ggc_deletable_rtab; *rt; rt++)
@@ -136,18 +166,11 @@ ggc_mark_roots (void)
       for (i = 0; i < rti->nelt; i++)
 	(*rti->cb) (*(void **)((char *)rti->base + rti->stride * i));
 
-  if (extra_root_vec 
-      && VEC_length(const_ggc_root_tab_t,extra_root_vec) > 0)
+  for (i = 0; VEC_iterate (const_ggc_root_tab_t, extra_root_vec, i, rtp); i++)
     {
-      const_ggc_root_tab_t rtp = NULL;
-      for (i=0; 
-	   VEC_iterate(const_ggc_root_tab_t, extra_root_vec, i, rtp); 
-	   i++) 
-	{
-	  for (rti = rtp; rti->base != NULL; rti++)
-	    for (i = 0; i < rti->nelt; i++)
-	      (*rti->cb) (*(void **) ((char *)rti->base + rti->stride * i));
-	}
+      for (rti = rtp; rti->base != NULL; rti++)
+        for (i = 0; i < rti->nelt; i++)
+          (*rti->cb) (*(void **) ((char *)rti->base + rti->stride * i));
     }
 
   if (ggc_protect_identifiers)
@@ -156,14 +179,10 @@ ggc_mark_roots (void)
   /* Now scan all hash tables that have objects which are to be deleted if
      they are not already marked.  */
   for (ct = gt_ggc_cache_rtab; *ct; ct++)
-    for (cti = *ct; cti->base != NULL; cti++)
-      if (*cti->base)
-	{
-	  ggc_set_mark (*cti->base);
-	  htab_traverse_noresize (*cti->base, ggc_htab_delete,
-				  CONST_CAST (void *, (const void *)cti));
-	  ggc_set_mark ((*cti->base)->entries);
-	}
+    ggc_scan_cache_tab (*ct);
+
+  for (i = 0; VEC_iterate (const_ggc_cache_tab_t, extra_cache_vec, i, ctp); i++)
+    ggc_scan_cache_tab (ctp);
 
   if (! ggc_protect_identifiers)
     ggc_purge_stringpool ();

gcc/ggc.h

@@ -272,9 +272,13 @@ extern const char *ggc_alloc_string (const char *contents, int length);
 extern void ggc_collect	(void);
 
 /* Register an additional root table.  This can be useful for some
-   plugins.  Does nothing if the passed pointer is null. */
+   plugins.  Does nothing if the passed pointer is NULL. */
 extern void ggc_register_root_tab (const struct ggc_root_tab *);
 
+/* Register an additional cache table.  This can be useful for some
+   plugins.  Does nothing if the passed pointer is NULL. */
+extern void ggc_register_cache_tab (const struct ggc_cache_tab *);
+
 /* Return the number of bytes allocated at the indicated address.  */
 extern size_t ggc_get_size (const void *);
 

gcc/plugin.c

@@ -57,6 +57,7 @@ const char *plugin_event_name[] =
   "PLUGIN_GGC_MARKING",
   "PLUGIN_GGC_END",
   "PLUGIN_REGISTER_GGC_ROOTS",
+  "PLUGIN_REGISTER_GGC_CACHES",
   "PLUGIN_START_UNIT", 
   "PLUGIN_EVENT_LAST"
 };
@@ -499,6 +500,10 @@ register_callback (const char *plugin_name,
 	gcc_assert (!callback);
         ggc_register_root_tab ((const struct ggc_root_tab*) user_data);
 	break;
+      case PLUGIN_REGISTER_GGC_CACHES:
+	gcc_assert (!callback);
+        ggc_register_cache_tab ((const struct ggc_cache_tab*) user_data);
+	break;
       case PLUGIN_FINISH_TYPE:
       case PLUGIN_START_UNIT:
       case PLUGIN_FINISH_UNIT:
@@ -566,6 +571,7 @@ invoke_plugin_callbacks (enum plugin_event event, void *gcc_data)
       case PLUGIN_PASS_MANAGER_SETUP:
       case PLUGIN_EVENT_LAST:
       case PLUGIN_REGISTER_GGC_ROOTS:
+      case PLUGIN_REGISTER_GGC_CACHES:
       default:
         gcc_assert (false);
     }