use `SET_SHAREABLE`

to adopt strict shareable rule.

* (basically) shareable objects only refer shareable objects
* (exception) shareable objects can refere unshareable objects
  but should not leak reference to unshareable objects to Ruby world

3 files changed, 10 insertions, 6 deletions

diff --git a/internal/class.h b/internal/class.h
index a791672cad..5d843e58da 100644
--- a/internal/class.h
+++ b/internal/class.h
@@ -555,7 +555,7 @@ RCLASS_WRITABLE_ENSURE_FIELDS_OBJ(VALUE obj)
     RUBY_ASSERT(RB_TYPE_P(obj, RUBY_T_CLASS) || RB_TYPE_P(obj, RUBY_T_MODULE));
     rb_classext_t *ext = RCLASS_EXT_WRITABLE(obj);
     if (!ext->fields_obj) {
-        RB_OBJ_WRITE(obj, &ext->fields_obj, rb_imemo_fields_new(obj, 1));
+        RB_OBJ_WRITE(obj, &ext->fields_obj, rb_imemo_fields_new(obj, 1, true));
     }
     return ext->fields_obj;
 }
@@ -762,6 +762,7 @@ RCLASS_SET_CLASSPATH(VALUE klass, VALUE classpath, bool permanent)
     rb_classext_t *ext = RCLASS_EXT_READABLE(klass);
     assert(BUILTIN_TYPE(klass) == T_CLASS || BUILTIN_TYPE(klass) == T_MODULE);
     assert(classpath == 0 || BUILTIN_TYPE(classpath) == T_STRING);
+    assert(FL_TEST_RAW(classpath, RUBY_FL_SHAREABLE));
 
     RB_OBJ_WRITE(klass, &(RCLASSEXT_CLASSPATH(ext)), classpath);
     RCLASSEXT_PERMANENT_CLASSPATH(ext) = permanent;
@@ -773,6 +774,7 @@ RCLASS_WRITE_CLASSPATH(VALUE klass, VALUE classpath, bool permanent)
     rb_classext_t *ext = RCLASS_EXT_WRITABLE(klass);
     assert(BUILTIN_TYPE(klass) == T_CLASS || BUILTIN_TYPE(klass) == T_MODULE);
     assert(classpath == 0 || BUILTIN_TYPE(classpath) == T_STRING);
+    assert(!RB_FL_ABLE(classpath) || FL_TEST_RAW(classpath, RUBY_FL_SHAREABLE));
 
     RB_OBJ_WRITE(klass, &(RCLASSEXT_CLASSPATH(ext)), classpath);
     RCLASSEXT_PERMANENT_CLASSPATH(ext) = permanent;
diff --git a/internal/gc.h b/internal/gc.h
index 7357bef732..ec408d7fac 100644
--- a/internal/gc.h
+++ b/internal/gc.h
@@ -353,5 +353,6 @@ ruby_sized_realloc_n(void *ptr, size_t new_count, size_t element_size, size_t ol
 #define ruby_sized_xfree ruby_sized_xfree_inlined
 
 void rb_gc_verify_shareable(VALUE);
+bool rb_gc_checking_shareable(void);
 
 #endif /* INTERNAL_GC_H */
diff --git a/internal/imemo.h b/internal/imemo.h
index 3b91ef4b81..f8bda26f0b 100644
--- a/internal/imemo.h
+++ b/internal/imemo.h
@@ -114,7 +114,8 @@ struct MEMO {
     } u3;
 };
 
-#define IMEMO_NEW(T, type, v0) ((T *)rb_imemo_new((type), (v0), sizeof(T)))
+#define IMEMO_NEW(T, type, v0) ((T *)rb_imemo_new((type), (v0), sizeof(T), false))
+#define SHAREABLE_IMEMO_NEW(T, type, v0) ((T *)rb_imemo_new((type), (v0), sizeof(T), true))
 
 /* ment is in method.h */
 
@@ -131,7 +132,7 @@ struct MEMO {
 #ifndef RUBY_RUBYPARSER_H
 typedef struct rb_imemo_tmpbuf_struct rb_imemo_tmpbuf_t;
 #endif
-VALUE rb_imemo_new(enum imemo_type type, VALUE v0, size_t size);
+VALUE rb_imemo_new(enum imemo_type type, VALUE v0, size_t size, bool is_shareable);
 VALUE rb_imemo_tmpbuf_new(void);
 struct vm_ifunc *rb_vm_ifunc_new(rb_block_call_func_t func, const void *data, int min_argc, int max_argc);
 static inline enum imemo_type imemo_type(VALUE imemo);
@@ -270,9 +271,9 @@ STATIC_ASSERT(imemo_fields_embed_offset, offsetof(struct RObject, as.heap.fields
 
 #define IMEMO_OBJ_FIELDS(fields) ((struct rb_fields *)fields)
 
-VALUE rb_imemo_fields_new(VALUE owner, size_t capa);
-VALUE rb_imemo_fields_new_complex(VALUE owner, size_t capa);
-VALUE rb_imemo_fields_new_complex_tbl(VALUE owner, st_table *tbl);
+VALUE rb_imemo_fields_new(VALUE owner, size_t capa, bool shareable);
+VALUE rb_imemo_fields_new_complex(VALUE owner, size_t capa, bool shareable);
+VALUE rb_imemo_fields_new_complex_tbl(VALUE owner, st_table *tbl, bool shareable);
 VALUE rb_imemo_fields_clone(VALUE fields_obj);
 void rb_imemo_fields_clear(VALUE fields_obj);