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class.c
2649 lines (2321 loc) · 72.2 KB
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class.c
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/**********************************************************************
class.c -
$Author$
created at: Tue Aug 10 15:05:44 JST 1993
Copyright (C) 1993-2007 Yukihiro Matsumoto
**********************************************************************/
/*!
* \addtogroup class
* \{
*/
#include "ruby/internal/config.h"
#include <ctype.h>
#include "constant.h"
#include "debug_counter.h"
#include "id_table.h"
#include "internal.h"
#include "internal/class.h"
#include "internal/eval.h"
#include "internal/hash.h"
#include "internal/object.h"
#include "internal/string.h"
#include "internal/variable.h"
#include "ruby/st.h"
#include "vm_core.h"
/* Flags of T_CLASS
*
* 2: RCLASS_SUPERCLASSES_INCLUDE_SELF
* The RCLASS_SUPERCLASSES contains the class as the last element.
* This means that this class owns the RCLASS_SUPERCLASSES list.
* if !SHAPE_IN_BASIC_FLAGS
* 4-19: SHAPE_FLAG_MASK
* Shape ID for the class.
* endif
*/
/* Flags of T_ICLASS
*
* 0: RICLASS_IS_ORIGIN
* 3: RICLASS_ORIGIN_SHARED_MTBL
* The T_ICLASS does not own the method table.
* if !SHAPE_IN_BASIC_FLAGS
* 4-19: SHAPE_FLAG_MASK
* Shape ID. This is set but not used.
* endif
*/
/* Flags of T_MODULE
*
* 1: RMODULE_ALLOCATED_BUT_NOT_INITIALIZED
* Module has not been initialized.
* 2: RCLASS_SUPERCLASSES_INCLUDE_SELF
* See RCLASS_SUPERCLASSES_INCLUDE_SELF in T_CLASS.
* 3: RMODULE_IS_REFINEMENT
* Module is used for refinements.
* if !SHAPE_IN_BASIC_FLAGS
* 4-19: SHAPE_FLAG_MASK
* Shape ID for the module.
* endif
*/
#define METACLASS_OF(k) RBASIC(k)->klass
#define SET_METACLASS_OF(k, cls) RBASIC_SET_CLASS(k, cls)
RUBY_EXTERN rb_serial_t ruby_vm_global_cvar_state;
static rb_subclass_entry_t *
push_subclass_entry_to_list(VALUE super, VALUE klass)
{
rb_subclass_entry_t *entry, *head;
entry = ZALLOC(rb_subclass_entry_t);
entry->klass = klass;
head = RCLASS_SUBCLASSES(super);
if (!head) {
head = ZALLOC(rb_subclass_entry_t);
RCLASS_SUBCLASSES(super) = head;
}
entry->next = head->next;
entry->prev = head;
if (head->next) {
head->next->prev = entry;
}
head->next = entry;
return entry;
}
void
rb_class_subclass_add(VALUE super, VALUE klass)
{
if (super && !UNDEF_P(super)) {
rb_subclass_entry_t *entry = push_subclass_entry_to_list(super, klass);
RCLASS_SUBCLASS_ENTRY(klass) = entry;
}
}
static void
rb_module_add_to_subclasses_list(VALUE module, VALUE iclass)
{
rb_subclass_entry_t *entry = push_subclass_entry_to_list(module, iclass);
RCLASS_MODULE_SUBCLASS_ENTRY(iclass) = entry;
}
void
rb_class_remove_subclass_head(VALUE klass)
{
rb_subclass_entry_t *head = RCLASS_SUBCLASSES(klass);
if (head) {
if (head->next) {
head->next->prev = NULL;
}
RCLASS_SUBCLASSES(klass) = NULL;
xfree(head);
}
}
void
rb_class_remove_from_super_subclasses(VALUE klass)
{
rb_subclass_entry_t *entry = RCLASS_SUBCLASS_ENTRY(klass);
if (entry) {
rb_subclass_entry_t *prev = entry->prev, *next = entry->next;
if (prev) {
prev->next = next;
}
if (next) {
next->prev = prev;
}
xfree(entry);
}
RCLASS_SUBCLASS_ENTRY(klass) = NULL;
}
void
rb_class_remove_from_module_subclasses(VALUE klass)
{
rb_subclass_entry_t *entry = RCLASS_MODULE_SUBCLASS_ENTRY(klass);
if (entry) {
rb_subclass_entry_t *prev = entry->prev, *next = entry->next;
if (prev) {
prev->next = next;
}
if (next) {
next->prev = prev;
}
xfree(entry);
}
RCLASS_MODULE_SUBCLASS_ENTRY(klass) = NULL;
}
void
rb_class_foreach_subclass(VALUE klass, void (*f)(VALUE, VALUE), VALUE arg)
{
// RCLASS_SUBCLASSES should always point to our head element which has NULL klass
rb_subclass_entry_t *cur = RCLASS_SUBCLASSES(klass);
// if we have a subclasses list, then the head is a placeholder with no valid
// class. So ignore it and use the next element in the list (if one exists)
if (cur) {
RUBY_ASSERT(!cur->klass);
cur = cur->next;
}
/* do not be tempted to simplify this loop into a for loop, the order of
operations is important here if `f` modifies the linked list */
while (cur) {
VALUE curklass = cur->klass;
cur = cur->next;
// do not trigger GC during f, otherwise the cur will become
// a dangling pointer if the subclass is collected
f(curklass, arg);
}
}
static void
class_detach_subclasses(VALUE klass, VALUE arg)
{
rb_class_remove_from_super_subclasses(klass);
}
void
rb_class_detach_subclasses(VALUE klass)
{
rb_class_foreach_subclass(klass, class_detach_subclasses, Qnil);
}
static void
class_detach_module_subclasses(VALUE klass, VALUE arg)
{
rb_class_remove_from_module_subclasses(klass);
}
void
rb_class_detach_module_subclasses(VALUE klass)
{
rb_class_foreach_subclass(klass, class_detach_module_subclasses, Qnil);
}
/**
* Allocates a struct RClass for a new class.
*
* \param flags initial value for basic.flags of the returned class.
* \param klass the class of the returned class.
* \return an uninitialized Class object.
* \pre \p klass must refer \c Class class or an ancestor of Class.
* \pre \code (flags | T_CLASS) != 0 \endcode
* \post the returned class can safely be \c #initialize 'd.
*
* \note this function is not Class#allocate.
*/
static VALUE
class_alloc(VALUE flags, VALUE klass)
{
size_t alloc_size = sizeof(struct RClass) + sizeof(rb_classext_t);
flags &= T_MASK;
if (RGENGC_WB_PROTECTED_CLASS) flags |= FL_WB_PROTECTED;
NEWOBJ_OF(obj, struct RClass, klass, flags, alloc_size, 0);
memset(RCLASS_EXT(obj), 0, sizeof(rb_classext_t));
/* ZALLOC
RCLASS_CONST_TBL(obj) = 0;
RCLASS_M_TBL(obj) = 0;
RCLASS_IV_INDEX_TBL(obj) = 0;
RCLASS_SET_SUPER((VALUE)obj, 0);
RCLASS_SUBCLASSES(obj) = NULL;
RCLASS_PARENT_SUBCLASSES(obj) = NULL;
RCLASS_MODULE_SUBCLASSES(obj) = NULL;
*/
RCLASS_SET_ORIGIN((VALUE)obj, (VALUE)obj);
RB_OBJ_WRITE(obj, &RCLASS_REFINED_CLASS(obj), Qnil);
RCLASS_SET_ALLOCATOR((VALUE)obj, 0);
return (VALUE)obj;
}
static void
RCLASS_M_TBL_INIT(VALUE c)
{
RCLASS_M_TBL(c) = rb_id_table_create(0);
}
/*!
* A utility function that wraps class_alloc.
*
* allocates a class and initializes safely.
* \param super a class from which the new class derives.
* \return a class object.
* \pre \a super must be a class.
* \post the metaclass of the new class is Class.
*/
VALUE
rb_class_boot(VALUE super)
{
VALUE klass = class_alloc(T_CLASS, rb_cClass);
RCLASS_SET_SUPER(klass, super);
RCLASS_M_TBL_INIT(klass);
return (VALUE)klass;
}
static VALUE *
class_superclasses_including_self(VALUE klass)
{
if (FL_TEST_RAW(klass, RCLASS_SUPERCLASSES_INCLUDE_SELF))
return RCLASS_SUPERCLASSES(klass);
size_t depth = RCLASS_SUPERCLASS_DEPTH(klass);
VALUE *superclasses = xmalloc(sizeof(VALUE) * (depth + 1));
if (depth > 0)
memcpy(superclasses, RCLASS_SUPERCLASSES(klass), sizeof(VALUE) * depth);
superclasses[depth] = klass;
RCLASS_SUPERCLASSES(klass) = superclasses;
FL_SET_RAW(klass, RCLASS_SUPERCLASSES_INCLUDE_SELF);
return superclasses;
}
void
rb_class_update_superclasses(VALUE klass)
{
VALUE super = RCLASS_SUPER(klass);
if (!RB_TYPE_P(klass, T_CLASS)) return;
if (UNDEF_P(super)) return;
// If the superclass array is already built
if (RCLASS_SUPERCLASSES(klass))
return;
// find the proper superclass
while (super != Qfalse && !RB_TYPE_P(super, T_CLASS)) {
super = RCLASS_SUPER(super);
}
// For BasicObject and uninitialized classes, depth=0 and ary=NULL
if (super == Qfalse)
return;
// Sometimes superclasses are set before the full ancestry tree is built
// This happens during metaclass construction
if (super != rb_cBasicObject && !RCLASS_SUPERCLASS_DEPTH(super)) {
rb_class_update_superclasses(super);
// If it is still unset we need to try later
if (!RCLASS_SUPERCLASS_DEPTH(super))
return;
}
RCLASS_SUPERCLASSES(klass) = class_superclasses_including_self(super);
RCLASS_SUPERCLASS_DEPTH(klass) = RCLASS_SUPERCLASS_DEPTH(super) + 1;
}
void
rb_check_inheritable(VALUE super)
{
if (!RB_TYPE_P(super, T_CLASS)) {
rb_raise(rb_eTypeError, "superclass must be an instance of Class (given an instance of %"PRIsVALUE")",
rb_obj_class(super));
}
if (RBASIC(super)->flags & FL_SINGLETON) {
rb_raise(rb_eTypeError, "can't make subclass of singleton class");
}
if (super == rb_cClass) {
rb_raise(rb_eTypeError, "can't make subclass of Class");
}
}
VALUE
rb_class_new(VALUE super)
{
Check_Type(super, T_CLASS);
rb_check_inheritable(super);
VALUE klass = rb_class_boot(super);
if (super != rb_cObject && super != rb_cBasicObject) {
RCLASS_EXT(klass)->max_iv_count = RCLASS_EXT(super)->max_iv_count;
}
return klass;
}
VALUE
rb_class_s_alloc(VALUE klass)
{
return rb_class_boot(0);
}
static void
clone_method(VALUE old_klass, VALUE new_klass, ID mid, const rb_method_entry_t *me)
{
if (me->def->type == VM_METHOD_TYPE_ISEQ) {
rb_cref_t *new_cref;
rb_vm_rewrite_cref(me->def->body.iseq.cref, old_klass, new_klass, &new_cref);
rb_add_method_iseq(new_klass, mid, me->def->body.iseq.iseqptr, new_cref, METHOD_ENTRY_VISI(me));
}
else {
rb_method_entry_set(new_klass, mid, me, METHOD_ENTRY_VISI(me));
}
}
struct clone_method_arg {
VALUE new_klass;
VALUE old_klass;
};
static enum rb_id_table_iterator_result
clone_method_i(ID key, VALUE value, void *data)
{
const struct clone_method_arg *arg = (struct clone_method_arg *)data;
clone_method(arg->old_klass, arg->new_klass, key, (const rb_method_entry_t *)value);
return ID_TABLE_CONTINUE;
}
struct clone_const_arg {
VALUE klass;
struct rb_id_table *tbl;
};
static int
clone_const(ID key, const rb_const_entry_t *ce, struct clone_const_arg *arg)
{
rb_const_entry_t *nce = ALLOC(rb_const_entry_t);
MEMCPY(nce, ce, rb_const_entry_t, 1);
RB_OBJ_WRITTEN(arg->klass, Qundef, ce->value);
RB_OBJ_WRITTEN(arg->klass, Qundef, ce->file);
rb_id_table_insert(arg->tbl, key, (VALUE)nce);
return ID_TABLE_CONTINUE;
}
static enum rb_id_table_iterator_result
clone_const_i(ID key, VALUE value, void *data)
{
return clone_const(key, (const rb_const_entry_t *)value, data);
}
static void
class_init_copy_check(VALUE clone, VALUE orig)
{
if (orig == rb_cBasicObject) {
rb_raise(rb_eTypeError, "can't copy the root class");
}
if (RCLASS_SUPER(clone) != 0 || clone == rb_cBasicObject) {
rb_raise(rb_eTypeError, "already initialized class");
}
if (FL_TEST(orig, FL_SINGLETON)) {
rb_raise(rb_eTypeError, "can't copy singleton class");
}
}
struct cvc_table_copy_ctx {
VALUE clone;
struct rb_id_table * new_table;
};
static enum rb_id_table_iterator_result
cvc_table_copy(ID id, VALUE val, void *data)
{
struct cvc_table_copy_ctx *ctx = (struct cvc_table_copy_ctx *)data;
struct rb_cvar_class_tbl_entry * orig_entry;
orig_entry = (struct rb_cvar_class_tbl_entry *)val;
struct rb_cvar_class_tbl_entry *ent;
ent = ALLOC(struct rb_cvar_class_tbl_entry);
ent->class_value = ctx->clone;
ent->cref = orig_entry->cref;
ent->global_cvar_state = orig_entry->global_cvar_state;
rb_id_table_insert(ctx->new_table, id, (VALUE)ent);
RB_OBJ_WRITTEN(ctx->clone, Qundef, ent->cref);
return ID_TABLE_CONTINUE;
}
static void
copy_tables(VALUE clone, VALUE orig)
{
if (RCLASS_CONST_TBL(clone)) {
rb_free_const_table(RCLASS_CONST_TBL(clone));
RCLASS_CONST_TBL(clone) = 0;
}
if (RCLASS_CVC_TBL(orig)) {
struct rb_id_table *rb_cvc_tbl = RCLASS_CVC_TBL(orig);
struct rb_id_table *rb_cvc_tbl_dup = rb_id_table_create(rb_id_table_size(rb_cvc_tbl));
struct cvc_table_copy_ctx ctx;
ctx.clone = clone;
ctx.new_table = rb_cvc_tbl_dup;
rb_id_table_foreach(rb_cvc_tbl, cvc_table_copy, &ctx);
RCLASS_CVC_TBL(clone) = rb_cvc_tbl_dup;
}
rb_id_table_free(RCLASS_M_TBL(clone));
RCLASS_M_TBL(clone) = 0;
if (!RB_TYPE_P(clone, T_ICLASS)) {
st_data_t id;
rb_iv_tbl_copy(clone, orig);
CONST_ID(id, "__tmp_classpath__");
rb_attr_delete(clone, id);
CONST_ID(id, "__classpath__");
rb_attr_delete(clone, id);
}
if (RCLASS_CONST_TBL(orig)) {
struct clone_const_arg arg;
arg.tbl = RCLASS_CONST_TBL(clone) = rb_id_table_create(0);
arg.klass = clone;
rb_id_table_foreach(RCLASS_CONST_TBL(orig), clone_const_i, &arg);
}
}
static bool ensure_origin(VALUE klass);
/**
* If this flag is set, that module is allocated but not initialized yet.
*/
enum {RMODULE_ALLOCATED_BUT_NOT_INITIALIZED = RUBY_FL_USER1};
static inline bool
RMODULE_UNINITIALIZED(VALUE module)
{
return FL_TEST_RAW(module, RMODULE_ALLOCATED_BUT_NOT_INITIALIZED);
}
void
rb_module_set_initialized(VALUE mod)
{
FL_UNSET_RAW(mod, RMODULE_ALLOCATED_BUT_NOT_INITIALIZED);
/* no more re-initialization */
}
void
rb_module_check_initializable(VALUE mod)
{
if (!RMODULE_UNINITIALIZED(mod)) {
rb_raise(rb_eTypeError, "already initialized module");
}
}
/* :nodoc: */
VALUE
rb_mod_init_copy(VALUE clone, VALUE orig)
{
switch (BUILTIN_TYPE(clone)) {
case T_CLASS:
case T_ICLASS:
class_init_copy_check(clone, orig);
break;
case T_MODULE:
rb_module_check_initializable(clone);
break;
default:
break;
}
if (!OBJ_INIT_COPY(clone, orig)) return clone;
/* cloned flag is refer at constant inline cache
* see vm_get_const_key_cref() in vm_insnhelper.c
*/
RCLASS_EXT(clone)->cloned = true;
RCLASS_EXT(orig)->cloned = true;
if (!FL_TEST(CLASS_OF(clone), FL_SINGLETON)) {
RBASIC_SET_CLASS(clone, rb_singleton_class_clone(orig));
rb_singleton_class_attached(METACLASS_OF(clone), (VALUE)clone);
}
RCLASS_SET_ALLOCATOR(clone, RCLASS_ALLOCATOR(orig));
copy_tables(clone, orig);
if (RCLASS_M_TBL(orig)) {
struct clone_method_arg arg;
arg.old_klass = orig;
arg.new_klass = clone;
RCLASS_M_TBL_INIT(clone);
rb_id_table_foreach(RCLASS_M_TBL(orig), clone_method_i, &arg);
}
if (RCLASS_ORIGIN(orig) == orig) {
RCLASS_SET_SUPER(clone, RCLASS_SUPER(orig));
}
else {
VALUE p = RCLASS_SUPER(orig);
VALUE orig_origin = RCLASS_ORIGIN(orig);
VALUE prev_clone_p = clone;
VALUE origin_stack = rb_ary_hidden_new(2);
VALUE origin[2];
VALUE clone_p = 0;
long origin_len;
int add_subclass;
VALUE clone_origin;
ensure_origin(clone);
clone_origin = RCLASS_ORIGIN(clone);
while (p && p != orig_origin) {
if (BUILTIN_TYPE(p) != T_ICLASS) {
rb_bug("non iclass between module/class and origin");
}
clone_p = class_alloc(RBASIC(p)->flags, METACLASS_OF(p));
/* We should set the m_tbl right after allocation before anything
* that can trigger GC to avoid clone_p from becoming old and
* needing to fire write barriers. */
RCLASS_SET_M_TBL(clone_p, RCLASS_M_TBL(p));
RCLASS_SET_SUPER(prev_clone_p, clone_p);
prev_clone_p = clone_p;
RCLASS_CONST_TBL(clone_p) = RCLASS_CONST_TBL(p);
RCLASS_SET_ALLOCATOR(clone_p, RCLASS_ALLOCATOR(p));
if (RB_TYPE_P(clone, T_CLASS)) {
RCLASS_SET_INCLUDER(clone_p, clone);
}
add_subclass = TRUE;
if (p != RCLASS_ORIGIN(p)) {
origin[0] = clone_p;
origin[1] = RCLASS_ORIGIN(p);
rb_ary_cat(origin_stack, origin, 2);
}
else if ((origin_len = RARRAY_LEN(origin_stack)) > 1 &&
RARRAY_AREF(origin_stack, origin_len - 1) == p) {
RCLASS_SET_ORIGIN(RARRAY_AREF(origin_stack, (origin_len -= 2)), clone_p);
RICLASS_SET_ORIGIN_SHARED_MTBL(clone_p);
rb_ary_resize(origin_stack, origin_len);
add_subclass = FALSE;
}
if (add_subclass) {
rb_module_add_to_subclasses_list(METACLASS_OF(p), clone_p);
}
p = RCLASS_SUPER(p);
}
if (p == orig_origin) {
if (clone_p) {
RCLASS_SET_SUPER(clone_p, clone_origin);
RCLASS_SET_SUPER(clone_origin, RCLASS_SUPER(orig_origin));
}
copy_tables(clone_origin, orig_origin);
if (RCLASS_M_TBL(orig_origin)) {
struct clone_method_arg arg;
arg.old_klass = orig;
arg.new_klass = clone;
RCLASS_M_TBL_INIT(clone_origin);
rb_id_table_foreach(RCLASS_M_TBL(orig_origin), clone_method_i, &arg);
}
}
else {
rb_bug("no origin for class that has origin");
}
rb_class_update_superclasses(clone);
}
return clone;
}
VALUE
rb_singleton_class_clone(VALUE obj)
{
return rb_singleton_class_clone_and_attach(obj, Qundef);
}
// Clone and return the singleton class of `obj` if it has been created and is attached to `obj`.
VALUE
rb_singleton_class_clone_and_attach(VALUE obj, VALUE attach)
{
const VALUE klass = METACLASS_OF(obj);
// Note that `rb_singleton_class()` can create situations where `klass` is
// attached to an object other than `obj`. In which case `obj` does not have
// a material singleton class attached yet and there is no singleton class
// to clone.
if (!(FL_TEST(klass, FL_SINGLETON) && RCLASS_ATTACHED_OBJECT(klass) == obj)) {
// nothing to clone
return klass;
}
else {
/* copy singleton(unnamed) class */
bool klass_of_clone_is_new;
VALUE clone = class_alloc(RBASIC(klass)->flags, 0);
if (BUILTIN_TYPE(obj) == T_CLASS) {
klass_of_clone_is_new = true;
RBASIC_SET_CLASS(clone, clone);
}
else {
VALUE klass_metaclass_clone = rb_singleton_class_clone(klass);
// When `METACLASS_OF(klass) == klass_metaclass_clone`, it means the
// recursive call did not clone `METACLASS_OF(klass)`.
klass_of_clone_is_new = (METACLASS_OF(klass) != klass_metaclass_clone);
RBASIC_SET_CLASS(clone, klass_metaclass_clone);
}
RCLASS_SET_SUPER(clone, RCLASS_SUPER(klass));
rb_iv_tbl_copy(clone, klass);
if (RCLASS_CONST_TBL(klass)) {
struct clone_const_arg arg;
arg.tbl = RCLASS_CONST_TBL(clone) = rb_id_table_create(0);
arg.klass = clone;
rb_id_table_foreach(RCLASS_CONST_TBL(klass), clone_const_i, &arg);
}
if (!UNDEF_P(attach)) {
rb_singleton_class_attached(clone, attach);
}
RCLASS_M_TBL_INIT(clone);
{
struct clone_method_arg arg;
arg.old_klass = klass;
arg.new_klass = clone;
rb_id_table_foreach(RCLASS_M_TBL(klass), clone_method_i, &arg);
}
if (klass_of_clone_is_new) {
rb_singleton_class_attached(METACLASS_OF(clone), clone);
}
FL_SET(clone, FL_SINGLETON);
return clone;
}
}
void
rb_singleton_class_attached(VALUE klass, VALUE obj)
{
if (FL_TEST(klass, FL_SINGLETON)) {
RCLASS_SET_ATTACHED_OBJECT(klass, obj);
}
}
/*!
* whether k is a meta^(n)-class of Class class
* @retval 1 if \a k is a meta^(n)-class of Class class (n >= 0)
* @retval 0 otherwise
*/
#define META_CLASS_OF_CLASS_CLASS_P(k) (METACLASS_OF(k) == (k))
static int
rb_singleton_class_has_metaclass_p(VALUE sklass)
{
return RCLASS_ATTACHED_OBJECT(METACLASS_OF(sklass)) == sklass;
}
int
rb_singleton_class_internal_p(VALUE sklass)
{
return (RB_TYPE_P(RCLASS_ATTACHED_OBJECT(sklass), T_CLASS) &&
!rb_singleton_class_has_metaclass_p(sklass));
}
/*!
* whether k has a metaclass
* @retval 1 if \a k has a metaclass
* @retval 0 otherwise
*/
#define HAVE_METACLASS_P(k) \
(FL_TEST(METACLASS_OF(k), FL_SINGLETON) && \
rb_singleton_class_has_metaclass_p(k))
/*!
* ensures \a klass belongs to its own eigenclass.
* @return the eigenclass of \a klass
* @post \a klass belongs to the returned eigenclass.
* i.e. the attached object of the eigenclass is \a klass.
* @note this macro creates a new eigenclass if necessary.
*/
#define ENSURE_EIGENCLASS(klass) \
(HAVE_METACLASS_P(klass) ? METACLASS_OF(klass) : make_metaclass(klass))
/*!
* Creates a metaclass of \a klass
* \param klass a class
* \return created metaclass for the class
* \pre \a klass is a Class object
* \pre \a klass has no singleton class.
* \post the class of \a klass is the returned class.
* \post the returned class is meta^(n+1)-class when \a klass is a meta^(n)-klass for n >= 0
*/
static inline VALUE
make_metaclass(VALUE klass)
{
VALUE super;
VALUE metaclass = rb_class_boot(Qundef);
FL_SET(metaclass, FL_SINGLETON);
rb_singleton_class_attached(metaclass, klass);
if (META_CLASS_OF_CLASS_CLASS_P(klass)) {
SET_METACLASS_OF(klass, metaclass);
SET_METACLASS_OF(metaclass, metaclass);
}
else {
VALUE tmp = METACLASS_OF(klass); /* for a meta^(n)-class klass, tmp is meta^(n)-class of Class class */
SET_METACLASS_OF(klass, metaclass);
SET_METACLASS_OF(metaclass, ENSURE_EIGENCLASS(tmp));
}
super = RCLASS_SUPER(klass);
while (RB_TYPE_P(super, T_ICLASS)) super = RCLASS_SUPER(super);
RCLASS_SET_SUPER(metaclass, super ? ENSURE_EIGENCLASS(super) : rb_cClass);
// Full class ancestry may not have been filled until we reach here.
rb_class_update_superclasses(METACLASS_OF(metaclass));
return metaclass;
}
/*!
* Creates a singleton class for \a obj.
* \pre \a obj must not a immediate nor a special const.
* \pre \a obj must not a Class object.
* \pre \a obj has no singleton class.
*/
static inline VALUE
make_singleton_class(VALUE obj)
{
VALUE orig_class = METACLASS_OF(obj);
VALUE klass = rb_class_boot(orig_class);
FL_SET(klass, FL_SINGLETON);
RBASIC_SET_CLASS(obj, klass);
rb_singleton_class_attached(klass, obj);
SET_METACLASS_OF(klass, METACLASS_OF(rb_class_real(orig_class)));
return klass;
}
static VALUE
boot_defclass(const char *name, VALUE super)
{
VALUE obj = rb_class_boot(super);
ID id = rb_intern(name);
rb_const_set((rb_cObject ? rb_cObject : obj), id, obj);
rb_vm_add_root_module(obj);
return obj;
}
/***********************************************************************
*
* Document-class: Refinement
*
* Refinement is a class of the +self+ (current context) inside +refine+
* statement. It allows to import methods from other modules, see #import_methods.
*/
#if 0 /* for RDoc */
/*
* Document-method: Refinement#import_methods
*
* call-seq:
* import_methods(module, ...) -> self
*
* Imports methods from modules. Unlike Module#include,
* Refinement#import_methods copies methods and adds them into the refinement,
* so the refinement is activated in the imported methods.
*
* Note that due to method copying, only methods defined in Ruby code can be imported.
*
* module StrUtils
* def indent(level)
* ' ' * level + self
* end
* end
*
* module M
* refine String do
* import_methods StrUtils
* end
* end
*
* using M
* "foo".indent(3)
* #=> " foo"
*
* module M
* refine String do
* import_methods Enumerable
* # Can't import method which is not defined with Ruby code: Enumerable#drop
* end
* end
*
*/
static VALUE
refinement_import_methods(int argc, VALUE *argv, VALUE refinement)
{
}
# endif
/*!
*--
* \private
* Initializes the world of objects and classes.
*
* At first, the function bootstraps the class hierarchy.
* It initializes the most fundamental classes and their metaclasses.
* - \c BasicObject
* - \c Object
* - \c Module
* - \c Class
* After the bootstrap step, the class hierarchy becomes as the following
* diagram.
*
* \image html boottime-classes.png
*
* Then, the function defines classes, modules and methods as usual.
* \ingroup class
*++
*/
void
Init_class_hierarchy(void)
{
rb_cBasicObject = boot_defclass("BasicObject", 0);
rb_cObject = boot_defclass("Object", rb_cBasicObject);
rb_gc_register_mark_object(rb_cObject);
/* resolve class name ASAP for order-independence */
rb_set_class_path_string(rb_cObject, rb_cObject, rb_fstring_lit("Object"));
rb_cModule = boot_defclass("Module", rb_cObject);
rb_cClass = boot_defclass("Class", rb_cModule);
rb_cRefinement = boot_defclass("Refinement", rb_cModule);
#if 0 /* for RDoc */
// we pretend it to be public, otherwise RDoc will ignore it
rb_define_method(rb_cRefinement, "import_methods", refinement_import_methods, -1);
#endif
rb_const_set(rb_cObject, rb_intern_const("BasicObject"), rb_cBasicObject);
RBASIC_SET_CLASS(rb_cClass, rb_cClass);
RBASIC_SET_CLASS(rb_cModule, rb_cClass);
RBASIC_SET_CLASS(rb_cObject, rb_cClass);
RBASIC_SET_CLASS(rb_cRefinement, rb_cClass);
RBASIC_SET_CLASS(rb_cBasicObject, rb_cClass);
ENSURE_EIGENCLASS(rb_cRefinement);
}
/*!
* \internal
* Creates a new *singleton class* for an object.
*
* \pre \a obj has no singleton class.
* \note DO NOT USE the function in an extension libraries. Use \ref rb_singleton_class.
* \param obj An object.
* \param unused ignored.
* \return The singleton class of the object.
*/
VALUE
rb_make_metaclass(VALUE obj, VALUE unused)
{
if (BUILTIN_TYPE(obj) == T_CLASS) {
return make_metaclass(obj);
}
else {
return make_singleton_class(obj);
}
}
VALUE
rb_define_class_id(ID id, VALUE super)
{
VALUE klass;
if (!super) super = rb_cObject;
klass = rb_class_new(super);
rb_make_metaclass(klass, METACLASS_OF(super));
return klass;
}
/*!
* Calls Class#inherited.
* \param super A class which will be called #inherited.
* NULL means Object class.
* \param klass A Class object which derived from \a super
* \return the value \c Class#inherited's returns
* \pre Each of \a super and \a klass must be a \c Class object.
*/
VALUE
rb_class_inherited(VALUE super, VALUE klass)
{
ID inherited;
if (!super) super = rb_cObject;
CONST_ID(inherited, "inherited");
return rb_funcall(super, inherited, 1, klass);
}
VALUE
rb_define_class(const char *name, VALUE super)
{
VALUE klass;
ID id;
id = rb_intern(name);
if (rb_const_defined(rb_cObject, id)) {
klass = rb_const_get(rb_cObject, id);
if (!RB_TYPE_P(klass, T_CLASS)) {
rb_raise(rb_eTypeError, "%s is not a class (%"PRIsVALUE")",
name, rb_obj_class(klass));
}
if (rb_class_real(RCLASS_SUPER(klass)) != super) {
rb_raise(rb_eTypeError, "superclass mismatch for class %s", name);
}
/* Class may have been defined in Ruby and not pin-rooted */
rb_vm_add_root_module(klass);
return klass;
}
if (!super) {
rb_raise(rb_eArgError, "no super class for `%s'", name);
}
klass = rb_define_class_id(id, super);
rb_vm_add_root_module(klass);
rb_const_set(rb_cObject, id, klass);
rb_class_inherited(super, klass);
return klass;