Make iseq conditional PPP.

We use the ISEQ_USE_COMPILE_DATA flag to determine if it is a PPP.  We
will remove it from the list of PPPs if it no longer has that flag.

internal/mmtk.h

@@ -80,6 +80,7 @@ typedef struct MMTk_RubyUpcalls {
     void *(*get_original_givtbl)(MMTk_ObjectReference object);
     void (*move_givtbl)(MMTk_ObjectReference old_objref, MMTk_ObjectReference new_objref);
     size_t (*vm_live_bytes)(void);
+    bool (*is_ppp)(MMTk_ObjectReference object);
     void (*update_frozen_strings_table)(void);
     void (*update_finalizer_table)(void);
     void (*update_obj_id_tables)(void);

iseq.c

@@ -436,6 +436,20 @@ rb_iseq_mark_and_move(rb_iseq_t *iseq, bool reference_updating)
     RUBY_MARK_LEAVE("iseq");
 }
 
+#if USE_MMTK
+bool
+rb_mmtk_iseq_is_ppp(VALUE iseq)
+{
+    return FL_TEST_RAW((VALUE)iseq, ISEQ_USE_COMPILE_DATA);
+}
+
+void
+rb_mmtk_iseq_register_ppp(rb_iseq_t *iseq)
+{
+    mmtk_register_ppp((MMTk_ObjectReference)iseq);
+}
+#endif
+
 static size_t
 param_keyword_size(const struct rb_iseq_param_keyword *pkw)
 {

iseq.h

@@ -15,6 +15,11 @@
 #include "vm_core.h"
 #include "prism_compile.h"
 
+#if USE_MMTK
+#include "internal/mmtk_macros.h"
+#include "internal/mmtk_support.h"
+#endif
+
 RUBY_EXTERN const int ruby_api_version[];
 #define ISEQ_MAJOR_VERSION ((unsigned int)ruby_api_version[0])
 #define ISEQ_MINOR_VERSION ((unsigned int)ruby_api_version[1])
@@ -151,7 +156,16 @@ static inline void
 ISEQ_COMPILE_DATA_ALLOC(rb_iseq_t *iseq)
 {
     iseq->aux.compile_data = ZALLOC(struct iseq_compile_data);
+    WHEN_USING_MMTK({
+        RUBY_ASSERT((iseq->flags & ISEQ_USE_COMPILE_DATA) == 0);
+    })
     iseq->flags |= ISEQ_USE_COMPILE_DATA;
+    WHEN_USING_MMTK({
+        // Defined in iseq.c
+        void rb_mmtk_iseq_register_ppp(rb_iseq_t *iseq);
+
+        rb_mmtk_iseq_register_ppp(iseq);
+    })
 }
 
 static inline void
@@ -184,6 +198,10 @@ unsigned int *rb_iseq_insns_info_decode_positions(const struct rb_iseq_constant_
 
 int rb_vm_insn_addr2opcode(const void *addr);
 
+#if USE_MMTK
+bool rb_mmtk_iseq_is_ppp(VALUE iseq);
+#endif
+
 RUBY_SYMBOL_EXPORT_BEGIN
 
 /* compile.c */

mmtk_support.c

@@ -10,6 +10,7 @@
 #include "internal/mmtk.h"
 #include "internal/thread.h"
 #include "internal/variable.h"
+#include "iseq.h"
 #include "ruby/ruby.h"
 #include "ractor_core.h"
 #include "vm_core.h"
@@ -615,6 +616,7 @@ rb_mmtk_is_ppp(VALUE obj) {
       case T_IMEMO:
         switch (imemo_type(obj)) {
           case imemo_iseq:
+            return rb_mmtk_iseq_is_ppp(obj);
           case imemo_tmpbuf:
           case imemo_ast:
           case imemo_ifunc:
@@ -629,6 +631,11 @@ rb_mmtk_is_ppp(VALUE obj) {
     }
 }
 
+static bool
+rb_mmtk_is_ppp_wrapper(MMTk_ObjectReference obj) {
+    rb_mmtk_is_ppp((VALUE)obj);
+}
+
 static void
 rb_mmtk_flush_ppp_buffer(struct rb_mmtk_values_buffer *buffer)
 {
@@ -1629,6 +1636,7 @@ MMTk_RubyUpcalls ruby_upcalls = {
     rb_mmtk_get_original_givtbl,
     rb_mmtk_move_givtbl,
     rb_mmtk_vm_live_bytes,
+    rb_mmtk_is_ppp_wrapper,
     rb_mmtk_update_frozen_strings_table,
     rb_mmtk_update_finalizer_table,
     rb_mmtk_update_obj_id_tables,