objc-runtime-new.h   [plain text]

/*
 * Copyright (c) 2005-2007 Apple Inc.  All Rights Reserved.
 * 
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

// Values for class_ro_t->flags
// These are emitted by the compiler and are part of the ABI. 
// class is a metaclass
#define RO_META               (1<<0)
// class is a root class
#define RO_ROOT               (1<<1)
// class has .cxx_construct/destruct implementations
#define RO_HAS_CXX_STRUCTORS  (1<<2)
// class has +load implementation
// #define RO_HAS_LOAD_METHOD    (1<<3)
// class has visibility=hidden set
#define RO_HIDDEN             (1<<4)
// class has attribute(objc_exception): OBJC_EHTYPE_$_ThisClass is non-weak
#define RO_EXCEPTION          (1<<5)
// class is in an unloadable bundle - must never be set by compiler
#define RO_FROM_BUNDLE        (1<<29)
// class is unrealized future class - must never be set by compiler
#define RO_FUTURE             (1<<30)
// class is realized - must never be set by compiler
#define RO_REALIZED           (1<<31)

// Values for class_rw_t->flags
// These are not emitted by the compiler and are never used in class_ro_t. 
// Their presence should be considered in future ABI versions.
// class_t->data is class_rw_t, not class_ro_t
#define RW_REALIZED           (1<<31)
// class is unresolved future class
#define RW_FUTURE             (1<<30)
// class is initialized
#define RW_INITIALIZED        (1<<29)
// class is initializing
#define RW_INITIALIZING       (1<<28)
// class_rw_t->ro is heap copy of class_ro_t
#define RW_COPIED_RO          (1<<27)
// class allocated but not yet registered
#define RW_CONSTRUCTING       (1<<26)
// class allocated and registered
#define RW_CONSTRUCTED        (1<<25)
// GC:  class has unsafe finalize method
#define RW_FINALIZE_ON_MAIN_THREAD (1<<24)
// class +load has been called
#define RW_LOADED             (1<<23)
// class does not share super's vtable
#define RW_SPECIALIZED_VTABLE (1<<22)
// class instances may have associative references
#define RW_INSTANCES_HAVE_ASSOCIATED_OBJECTS (1<<21)

typedef struct method_t {
    SEL name;
    const char *types;
    IMP imp;
} method_t;

typedef struct method_list_t {
    uint32_t entsize_NEVER_USE;  // low 2 bits used for fixup markers
    uint32_t count;
    struct method_t first;
} method_list_t;

typedef struct ivar_t {
    // *offset is 64-bit by accident even though other 
    // fields restrict total instance size to 32-bit. 
    uintptr_t *offset;
    const char *name;
    const char *type;
    // alignment is sometimes -1; use ivar_alignment() instead
    uint32_t alignment  __attribute__((deprecated));
    uint32_t size;
} ivar_t;

typedef struct ivar_list_t {
    uint32_t entsize;
    uint32_t count;
    struct ivar_t first;
} ivar_list_t;

typedef uintptr_t protocol_ref_t;  // protocol_t *, but unremapped

typedef struct protocol_t {
    id isa;
    const char *name;
    struct protocol_list_t *protocols;
    method_list_t *instanceMethods;
    method_list_t *classMethods;
    method_list_t *optionalInstanceMethods;
    method_list_t *optionalClassMethods;
    struct objc_property_list *instanceProperties;
} protocol_t;

typedef struct protocol_list_t {
    // count is 64-bit by accident. 
    uintptr_t count;
    protocol_ref_t list[0]; // variable-size
} protocol_list_t;

typedef struct class_ro_t {
    uint32_t flags;
    uint32_t instanceStart;
    uint32_t instanceSize;
#ifdef __LP64__
    uint32_t reserved;
#endif

    const uint8_t * ivarLayout;
    
    const char * name;
    const method_list_t * baseMethods;
    const protocol_list_t * baseProtocols;
    const ivar_list_t * ivars;

    const uint8_t * weakIvarLayout;
    const struct objc_property_list *baseProperties;
} class_ro_t;

typedef struct class_rw_t {
    uint32_t flags;
    uint32_t version;

    const class_ro_t *ro;
    
    struct method_list_t **methods;
    struct chained_property_list *properties;
    struct protocol_list_t ** protocols;

    struct class_t *firstSubclass;
    struct class_t *nextSiblingClass;
} class_rw_t;

typedef struct class_t {
    struct class_t *isa;
    struct class_t *superclass;
    Cache cache;
    IMP *vtable;
    class_rw_t *data;
} class_t;

typedef struct category_t {
    const char *name;
    struct class_t *cls;
    struct method_list_t *instanceMethods;
    struct method_list_t *classMethods;
    struct protocol_list_t *protocols;
    struct objc_property_list *instanceProperties;
} category_t;

struct objc_super2 {
    id receiver;
    Class current_class;
};