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ruby--ruby/internal/class.h
Jeremy Evans ad729a1d11 Fix origin iclass pointer for modules
If a module has an origin, and that module is included in another
module or class, previously the iclass created for the module had
an origin pointer to the module's origin instead of the iclass's
origin.

Setting the origin pointer correctly requires using a stack, since
the origin iclass is not created until after the iclass itself.
Use a hidden ruby array to implement that stack.

Correctly assigning the origin pointers in the iclass caused a
use-after-free in GC.  If a module with an origin is included
in a class, the iclass shares a method table with the module
and the iclass origin shares a method table with module origin.

Mark iclass origin with a flag that notes that even though the
iclass is an origin, it shares a method table, so the method table
should not be garbage collected.  The shared method table will be
garbage collected when the module origin is garbage collected.
I've tested that this does not introduce a memory leak.

This change caused a VM assertion failure, which was traced to callable
method entries using the incorrect defined_class.  Update
rb_vm_check_redefinition_opt_method and find_defined_class_by_owner
to treat iclass origins different than class origins to avoid this
issue.

This also includes a fix for Module#included_modules to skip
iclasses with origins.

Fixes [Bug #16736]
2020-05-22 20:31:23 -07:00

170 lines
5.6 KiB
C

#ifndef INTERNAL_CLASS_H /*-*-C-*-vi:se ft=c:*/
#define INTERNAL_CLASS_H
/**
* @file
* @author Ruby developers <ruby-core@ruby-lang.org>
* @copyright This file is a part of the programming language Ruby.
* Permission is hereby granted, to either redistribute and/or
* modify this file, provided that the conditions mentioned in the
* file COPYING are met. Consult the file for details.
* @brief Internal header for Class.
*/
#include "id_table.h" /* for struct rb_id_table */
#include "internal/gc.h" /* for RB_OBJ_WRITE */
#include "internal/serial.h" /* for rb_serial_t */
#include "ruby/internal/stdbool.h" /* for bool */
#include "ruby/intern.h" /* for rb_alloc_func_t */
#include "ruby/ruby.h" /* for struct RBasic */
#ifdef RClass
# undef RClass /* See also include/ruby/backward.h */
#endif
#ifdef RCLASS_SUPER
# undef RCLASS_SUPER
#endif
struct rb_deprecated_classext_struct {
char conflict[sizeof(VALUE) * 3];
};
struct rb_subclass_entry {
VALUE klass;
struct rb_subclass_entry *next;
};
struct rb_classext_struct {
struct st_table *iv_index_tbl;
struct st_table *iv_tbl;
#if SIZEOF_SERIAL_T == SIZEOF_VALUE /* otherwise m_tbl is in struct RClass */
struct rb_id_table *m_tbl;
#endif
struct rb_id_table *const_tbl;
struct rb_id_table *callable_m_tbl;
struct rb_id_table *cc_tbl; /* ID -> [[ci, cc1], cc2, ...] */
struct rb_subclass_entry *subclasses;
struct rb_subclass_entry **parent_subclasses;
/**
* In the case that this is an `ICLASS`, `module_subclasses` points to the link
* in the module's `subclasses` list that indicates that the klass has been
* included. Hopefully that makes sense.
*/
struct rb_subclass_entry **module_subclasses;
#if SIZEOF_SERIAL_T != SIZEOF_VALUE /* otherwise class_serial is in struct RClass */
rb_serial_t class_serial;
#endif
const VALUE origin_;
const VALUE refined_class;
rb_alloc_func_t allocator;
const VALUE includer;
};
struct RClass {
struct RBasic basic;
VALUE super;
struct rb_classext_struct *ptr;
#if SIZEOF_SERIAL_T == SIZEOF_VALUE
/* Class serial is as wide as VALUE. Place it here. */
rb_serial_t class_serial;
#else
/* Class serial does not fit into struct RClass. Place m_tbl instead. */
struct rb_id_table *m_tbl;
#endif
};
typedef struct rb_subclass_entry rb_subclass_entry_t;
typedef struct rb_classext_struct rb_classext_t;
#define RCLASS_EXT(c) (RCLASS(c)->ptr)
#define RCLASS_IV_TBL(c) (RCLASS_EXT(c)->iv_tbl)
#define RCLASS_CONST_TBL(c) (RCLASS_EXT(c)->const_tbl)
#if SIZEOF_SERIAL_T == SIZEOF_VALUE
# define RCLASS_M_TBL(c) (RCLASS_EXT(c)->m_tbl)
#else
# define RCLASS_M_TBL(c) (RCLASS(c)->m_tbl)
#endif
#define RCLASS_CALLABLE_M_TBL(c) (RCLASS_EXT(c)->callable_m_tbl)
#define RCLASS_CC_TBL(c) (RCLASS_EXT(c)->cc_tbl)
#define RCLASS_IV_INDEX_TBL(c) (RCLASS_EXT(c)->iv_index_tbl)
#define RCLASS_ORIGIN(c) (RCLASS_EXT(c)->origin_)
#define RCLASS_REFINED_CLASS(c) (RCLASS_EXT(c)->refined_class)
#if SIZEOF_SERIAL_T == SIZEOF_VALUE
# define RCLASS_SERIAL(c) (RCLASS(c)->class_serial)
#else
# define RCLASS_SERIAL(c) (RCLASS_EXT(c)->class_serial)
#endif
#define RCLASS_INCLUDER(c) (RCLASS_EXT(c)->includer)
#define RICLASS_IS_ORIGIN FL_USER5
#define RCLASS_CLONED FL_USER6
#define RCLASS_REFINED_BY_ANY FL_USER7
#define RICLASS_ORIGIN_SHARED_MTBL FL_USER8
/* class.c */
void rb_class_subclass_add(VALUE super, VALUE klass);
void rb_class_remove_from_super_subclasses(VALUE);
int rb_singleton_class_internal_p(VALUE sklass);
VALUE rb_class_boot(VALUE);
VALUE rb_make_metaclass(VALUE, VALUE);
VALUE rb_include_class_new(VALUE, VALUE);
void rb_class_foreach_subclass(VALUE klass, void (*f)(VALUE, VALUE), VALUE);
void rb_class_detach_subclasses(VALUE);
void rb_class_detach_module_subclasses(VALUE);
void rb_class_remove_from_module_subclasses(VALUE);
VALUE rb_obj_methods(int argc, const VALUE *argv, VALUE obj);
VALUE rb_obj_protected_methods(int argc, const VALUE *argv, VALUE obj);
VALUE rb_obj_private_methods(int argc, const VALUE *argv, VALUE obj);
VALUE rb_obj_public_methods(int argc, const VALUE *argv, VALUE obj);
VALUE rb_special_singleton_class(VALUE);
VALUE rb_singleton_class_clone_and_attach(VALUE obj, VALUE attach);
VALUE rb_singleton_class_get(VALUE obj);
int rb_class_has_methods(VALUE c);
void rb_undef_methods_from(VALUE klass, VALUE super);
static inline void RCLASS_SET_ORIGIN(VALUE klass, VALUE origin);
static inline void RICLASS_SET_ORIGIN_SHARED_MTBL(VALUE iclass);
static inline VALUE RCLASS_SUPER(VALUE klass);
static inline VALUE RCLASS_SET_SUPER(VALUE klass, VALUE super);
static inline void RCLASS_SET_INCLUDER(VALUE iclass, VALUE klass);
MJIT_SYMBOL_EXPORT_BEGIN
VALUE rb_class_inherited(VALUE, VALUE);
VALUE rb_keyword_error_new(const char *, VALUE);
MJIT_SYMBOL_EXPORT_END
static inline void
RCLASS_SET_ORIGIN(VALUE klass, VALUE origin)
{
RB_OBJ_WRITE(klass, &RCLASS_ORIGIN(klass), origin);
if (klass != origin) FL_SET(origin, RICLASS_IS_ORIGIN);
}
static inline void
RICLASS_SET_ORIGIN_SHARED_MTBL(VALUE iclass)
{
FL_SET(iclass, RICLASS_ORIGIN_SHARED_MTBL);
}
static inline void
RCLASS_SET_INCLUDER(VALUE iclass, VALUE klass)
{
RB_OBJ_WRITE(iclass, &RCLASS_INCLUDER(iclass), klass);
}
static inline VALUE
RCLASS_SUPER(VALUE klass)
{
return RCLASS(klass)->super;
}
static inline VALUE
RCLASS_SET_SUPER(VALUE klass, VALUE super)
{
if (super) {
rb_class_remove_from_super_subclasses(klass);
rb_class_subclass_add(super, klass);
}
RB_OBJ_WRITE(klass, &RCLASS(klass)->super, super);
return super;
}
#endif /* INTERNAL_CLASS_H */