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/* GNU Objective-C Runtime API - Modern API
Copyright (C) 2010-2019 Free Software Foundation, Inc.
Contributed by Nicola Pero <nicola.pero@meta-innovation.com>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.
GCC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifndef __objc_runtime_INCLUDE_GNU
#define __objc_runtime_INCLUDE_GNU
/*
This file declares the "modern" GNU Objective-C Runtime API.
This API replaced the "traditional" GNU Objective-C Runtime API
(which used to be declared in objc/objc-api.h) which is the one
supported by older versions of the GNU Objective-C Runtime. The
"modern" API is very similar to the API used by the modern
Apple/NeXT runtime.
*/
#include "objc.h"
#include "objc-decls.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/* An 'Ivar' represents an instance variable. It holds information
about the name, type and offset of the instance variable. */
typedef struct objc_ivar *Ivar;
/* A 'Property' represents a property. It holds information about the
name of the property, and its attributes.
Compatibility Note: the Apple/NeXT runtime defines this as
objc_property_t, so we define it that way as well, but obviously
Property is the right name. */
typedef struct objc_property *Property;
typedef struct objc_property *objc_property_t;
/* A 'Method' represents a method. It holds information about the
name, types and the IMP of the method. */
typedef struct objc_method *Method;
/* A 'Category' represents a category. It holds information about the
name of the category, the class it belongs to, and the methods,
protocols and such like provided by the category. */
typedef struct objc_category *Category;
/* 'Protocol' is defined in objc/objc.h (which is included by this
file). */
/* Method descriptor returned by introspective Object methods. At the
moment, this is really just the first part of the more complete
objc_method structure used internally by the runtime. (PS: In the
GNU Objective-C Runtime, selectors already include a type, so an
objc_method_description does not add much to a SEL. But in other
runtimes, that is not the case, which is why
objc_method_description exists). */
struct objc_method_description
{
SEL name; /* Selector (name and signature) */
char *types; /* Type encoding */
};
/* The following are used in encode strings to describe the type of
Ivars and Methods. */
#define _C_ID '@'
#define _C_CLASS '#'
#define _C_SEL ':'
#define _C_CHR 'c'
#define _C_UCHR 'C'
#define _C_SHT 's'
#define _C_USHT 'S'
#define _C_INT 'i'
#define _C_UINT 'I'
#define _C_LNG 'l'
#define _C_ULNG 'L'
#define _C_LNG_LNG 'q'
#define _C_ULNG_LNG 'Q'
#define _C_FLT 'f'
#define _C_DBL 'd'
#define _C_LNG_DBL 'D'
#define _C_BFLD 'b'
#define _C_BOOL 'B'
#define _C_VOID 'v'
#define _C_UNDEF '?'
#define _C_PTR '^'
#define _C_CHARPTR '*'
#define _C_ARY_B '['
#define _C_ARY_E ']'
#define _C_UNION_B '('
#define _C_UNION_E ')'
#define _C_STRUCT_B '{'
#define _C_STRUCT_E '}'
#define _C_VECTOR '!'
#define _C_COMPLEX 'j'
/* _C_ATOM is never generated by the compiler. You can treat it as
equivalent to "*". */
#define _C_ATOM '%'
/* The following are used in encode strings to describe some
qualifiers of method and ivar types. */
#define _C_CONST 'r'
#define _C_IN 'n'
#define _C_INOUT 'N'
#define _C_OUT 'o'
#define _C_BYCOPY 'O'
#define _C_BYREF 'R'
#define _C_ONEWAY 'V'
#define _C_GCINVISIBLE '|'
/* The same when used as flags. */
#define _F_CONST 0x01
#define _F_IN 0x01
#define _F_OUT 0x02
#define _F_INOUT 0x03
#define _F_BYCOPY 0x04
#define _F_BYREF 0x08
#define _F_ONEWAY 0x10
#define _F_GCINVISIBLE 0x20
/** Implementation: the following functions are defined inline. */
/* Return the class of 'object', or Nil if the object is nil. If
'object' is a class, the meta class is returned; if 'object' is a
meta class, the root meta class is returned (note that this is
different from the traditional GNU Objective-C Runtime API function
object_get_class(), which for a meta class would return the meta
class itself). This function is inline, so it is really fast and
should be used instead of accessing object->class_pointer
directly. */
static inline Class
object_getClass (id object)
{
if (object != nil)
return object->class_pointer;
else
return Nil;
}
/** Implementation: the following functions are in selector.c. */
/* Return the name of a given selector. If 'selector' is NULL, return
"<null selector>". */
objc_EXPORT const char *sel_getName (SEL selector);
/* Return the type of a given selector. Return NULL if selector is
NULL.
Compatibility Note: the Apple/NeXT runtime has untyped selectors,
so it does not have this function, which is specific to the GNU
Runtime. */
objc_EXPORT const char *sel_getTypeEncoding (SEL selector);
/* This is the same as sel_registerName (). Please use
sel_registerName () instead. */
objc_EXPORT SEL sel_getUid (const char *name);
/* Register a selector with a given name (but unspecified types). If
you know the types, it is better to call sel_registerTypedName().
If a selector with this name and no types already exists, it is
returned. Note that this function should really be called
'objc_registerSelector'. Return NULL if 'name' is NULL. */
objc_EXPORT SEL sel_registerName (const char *name);
/* Register a selector with a given name and types. If a selector
with this name and types already exists, it is returned. Note that
this function should really be called 'objc_registerTypedSelector',
and it's called 'sel_registerTypedName' only for consistency with
'sel_registerName'. Return NULL if 'name' is NULL.
Compatibility Note: the Apple/NeXT runtime has untyped selectors,
so it does not have this function, which is specific to the GNU
Runtime. */
objc_EXPORT SEL sel_registerTypedName (const char *name, const char *type);
/* Return YES if first_selector is the same as second_selector, and NO
if not. */
objc_EXPORT BOOL sel_isEqual (SEL first_selector, SEL second_selector);
/* Return all the selectors with the supplied name. In the GNU
runtime, selectors are typed and there may be multiple selectors
with the same name but a different type. The return value of the
function is a pointer to an area, allocated with malloc(), that
contains all the selectors with the supplier name known to the
runtime. The list is terminated by NULL. Optionally, if you pass
a non-NULL 'numberOfReturnedSelectors' pointer, the unsigned int
that it points to will be filled with the number of selectors
returned.
Compatibility Note: the Apple/NeXT runtime has untyped selectors,
so it does not have this function, which is specific to the GNU
Runtime. */
objc_EXPORT SEL * sel_copyTypedSelectorList (const char *name,
unsigned int *numberOfReturnedSelectors);
/* Return a selector with name 'name' and a non-zero type encoding, if
there is a single selector with a type, and with that name,
registered with the runtime. If there is no such selector, or if
there are multiple selectors with the same name but conflicting
types, NULL is returned. Return NULL if 'name' is NULL.
This is useful if you have the name of the selector, and would
really like to get a selector for it that includes the type
encoding. Unfortunately, if the program contains multiple selector
with the same name but different types, sel_getTypedSelector cannot
possibly know which one you need, and so will return NULL.
Compatibility Note: the Apple/NeXT runtime has untyped selectors,
so it does not have this function, which is specific to the GNU
Runtime. */
objc_EXPORT SEL sel_getTypedSelector (const char *name);
/** Implementation: the following functions are in objects.c. */
/* Create an instance of class 'class_', adding extraBytes to the size
of the returned object. This method allocates the appropriate
amount of memory for the instance, initializes it to zero, then
calls all the C++ constructors on appropriate C++ instance
variables of the instance (if any) (TODO: The C++ constructors bit
is not implemented yet). */
objc_EXPORT id class_createInstance (Class class_, size_t extraBytes);
/* Copy an object and return the copy. extraBytes should be identical
to the extraBytes parameter that was passed when creating the
original object. */
objc_EXPORT id object_copy (id object, size_t extraBytes);
/* Dispose of an object. This method calls the appropriate C++
destructors on appropriate C++ instance variables of the instance
(if any) (TODO: This is not implemented yet), then frees the memory
for the instance. */
objc_EXPORT id object_dispose (id object);
/* Return the name of the class of 'object'. If 'object' is 'nil',
returns "Nil". */
objc_EXPORT const char * object_getClassName (id object);
/* Change the class of object to be class_. Return the previous class
of object. This is currently not really thread-safe. */
objc_EXPORT Class object_setClass (id object, Class class_);
/** Implementation: the following functions are in ivars.c. */
/* Return an instance variable given the class and the instance
variable name. This is an expensive function to call, so try to
reuse the returned Ivar if you can. */
objc_EXPORT Ivar class_getInstanceVariable (Class class_, const char *name);
/* Return a class variable given the class and the class variable
name. This is an expensive function to call, so try to reuse the
returned Ivar if you can.
This function always returns NULL since class variables are
currently unavailable in Objective-C. */
objc_EXPORT Ivar class_getClassVariable (Class class_, const char *name);
/* If the object was created in class_createInstance() with some
extraBytes, returns a pointer to them. If it was not, then the
returned pointer may make no sense. */
objc_EXPORT void * object_getIndexedIvars (id object);
/* Get the value of an instance variable of type 'id'. The function
returns the instance variable. To get the value of the instance
variable, you should pass as 'returnValue' a pointer to an 'id';
the value will be copied there. Note that 'returnValue' is really
a 'void *', not a 'void **'. This function really works only with
instance variables of type 'id'; for other types of instance
variables, access directly the data at (char *)object +
ivar_getOffset (ivar). */
objc_EXPORT Ivar object_getInstanceVariable (id object, const char *name, void **returnValue);
/* Set the value of an instance variable. The value to set is passed
in 'newValue' (which really is an 'id', not a 'void *'). The
function returns the instance variable. This function really works
only with instance variables of type 'id'; for other types of
instance variables, access directly the data at (char *)object +
ivar_getOffset (ivar). */
objc_EXPORT Ivar object_setInstanceVariable (id object, const char *name, void *newValue);
/* Get the value of an instance variable of type 'id' of the object
'object'. This is faster than object_getInstanceVariable if you
already have the instance variable because it avoids the expensive
call to class_getInstanceVariable that is done by
object_getInstanceVariable. */
objc_EXPORT id object_getIvar (id object, Ivar variable);
/* Set the value of an instance variable of type 'id' of the object
'object'. This is faster than object_setInstanceVariable if you
already have the instance variable because it avoids the expensive
call to class_getInstanceVariable that is done by
object_setInstanceVariable. */
objc_EXPORT void object_setIvar (id object, Ivar variable, id value);
/* Return the name of the instance variable. Return NULL if
'variable' is NULL. */
objc_EXPORT const char * ivar_getName (Ivar variable);
/* Return the offset of the instance variable from the start of the
object data. Return 0 if 'variable' is NULL. */
objc_EXPORT ptrdiff_t ivar_getOffset (Ivar variable);
/* Return the type encoding of the variable. Return NULL if
'variable' is NULL. */
objc_EXPORT const char * ivar_getTypeEncoding (Ivar variable);
/* Return all the instance variables of the class. The return value
of the function is a pointer to an area, allocated with malloc(),
that contains all the instance variables of the class. It does not
include instance variables of superclasses. The list is terminated
by NULL. Optionally, if you pass a non-NULL
'numberOfReturnedIvars' pointer, the unsigned int that it points to
will be filled with the number of instance variables returned.
Return NULL for classes still in construction (ie, allocated using
objc_allocatedClassPair() but not yet registered with the runtime
using objc_registerClassPair()). */
objc_EXPORT Ivar * class_copyIvarList (Class class_, unsigned int *numberOfReturnedIvars);
/* Add an instance variable with name 'ivar_name' to class 'class_',
where 'class_' is a class in construction that has been created
using objc_allocateClassPair() and has not been registered with the
runtime using objc_registerClassPair() yet. You cannot add
instance variables to classes already registered with the runtime.
'size' is the size of the instance variable, 'log_2_of_alignment'
the alignment as a power of 2 (so 0 means alignment to a 1 byte
boundary, 1 means alignment to a 2 byte boundary, 2 means alignment
to a 4 byte boundary, etc), and 'type' the type encoding of the
variable type. You can use sizeof(), log2(__alignof__()) and
@encode() to determine the right 'size', 'alignment' and 'type' for
your instance variable. For example, to add an instance variable
name "my_variable" and of type 'id', you can use:
class_addIvar (class, "my_variable", sizeof (id), log2 ( __alignof__ (id)),
@encode (id));
Return YES if the variable was added, and NO if not. In
particular, return NO if 'class_' is Nil, or a meta-class or a
class not in construction. Return Nil also if 'ivar_name' or
'type' is NULL, or 'size' is 0.
*/
objc_EXPORT BOOL class_addIvar (Class class_, const char * ivar_name, size_t size,
unsigned char log_2_of_alignment, const char *type);
/* Return the name of the property. Return NULL if 'property' is
NULL. */
objc_EXPORT const char * property_getName (Property property);
/* Return the attributes of the property as a string. Return NULL if
'property' is NULL. */
objc_EXPORT const char * property_getAttributes (Property property);
/* Return the property with name 'propertyName' of the class 'class_'.
This function returns NULL if the required property cannot be
found. Return NULL if 'class_' or 'propertyName' is NULL.
Note that the traditional ABI does not store the list of properties
of a class in a compiled module, so the traditional ABI will always
return NULL. */
objc_EXPORT Property class_getProperty (Class class_, const char *propertyName);
/* Return all the properties of the class. The return value
of the function is a pointer to an area, allocated with malloc(),
that contains all the properties of the class. It does not
include properties of superclasses. The list is terminated
by NULL. Optionally, if you pass a non-NULL
'numberOfReturnedIvars' pointer, the unsigned int that it points to
will be filled with the number of properties returned.
Note that the traditional ABI does not store the list of properties
of a class in a compiled module, so the traditional ABI will always
return an empty list. */
objc_EXPORT Property * class_copyPropertyList
(Class class_, unsigned int *numberOfReturnedProperties);
/* Return the ivar layout for class 'class_'.
At the moment this function always returns NULL. */
objc_EXPORT const char * class_getIvarLayout (Class class_);
/* Return the weak ivar layout for class 'class_'.
At the moment this function always returns NULL. */
objc_EXPORT const char * class_getWeakIvarLayout (Class class_);
/* Set the ivar layout for class 'class_'.
At the moment, this function does nothing. */
objc_EXPORT void class_setIvarLayout (Class class_, const char *layout);
/* Set the weak ivar layout for class 'class_'.
At the moment, this function does nothing. With the GNU runtime,
you should use class_ivar_set_gcinvisible () to hide variables from
the Garbage Collector. */
objc_EXPORT void class_setWeakIvarLayout (Class class_, const char *layout);
/** Implementation: the following functions are in class.c. */
/* Compatibility Note: The Apple/NeXT runtime does not have
objc_get_unknown_class_handler and
objc_setGetUnknownClassHandler(). They provide functionality that
the traditional GNU Objective-C Runtime API used to provide via the
_objc_lookup_class hook. */
/* An 'objc_get_unknown_class_handler' function is used by
objc_getClass() to get a class that is currently unknown to the
compiler. You could use it for example to have the class loaded by
dynamically loading a library. 'class_name' is the name of the
class. The function should return the Class object if it manages to
load the class, and Nil if not. */
typedef Class (*objc_get_unknown_class_handler)(const char *class_name);
/* Sets a new handler function for getting unknown classes (to be used
by objc_getClass () and related), and returns the previous one.
This function is not safe to call in a multi-threaded environment
because other threads may be trying to use the get unknown class
handler while you change it! */
objc_EXPORT
objc_get_unknown_class_handler
objc_setGetUnknownClassHandler (objc_get_unknown_class_handler new_handler);
/* Return the class with name 'name', if it is already registered with
the runtime. If it is not registered, and
objc_setGetUnknownClassHandler() has been called to set a handler
for unknown classes, the handler is called to give it a chance to
load the class in some other way. If the class is not known to the
runtime and the handler is not set or returns Nil, objc_getClass()
returns Nil. */
objc_EXPORT Class objc_getClass (const char *name);
/* Return the class with name 'name', if it is already registered with
the runtime. Return Nil if not. This function does not call the
objc_get_unknown_class_handler function if the class is not
found. */
objc_EXPORT Class objc_lookUpClass (const char *name);
/* Return the meta class associated to the class with name 'name', if
it is already registered with the runtime. First, it finds the
class using objc_getClass(). Then, it returns the associated meta
class. If the class could not be found using objc_getClass(),
returns Nil. */
objc_EXPORT Class objc_getMetaClass (const char *name);
/* This is identical to objc_getClass(), but if the class is not found,
it aborts the process instead of returning Nil. */
objc_EXPORT Class objc_getRequiredClass (const char *name);
/* If 'returnValue' is NULL, 'objc_getClassList' returns the number of
classes currently registered with the runtime. If 'returnValue' is
not NULL, it should be a (Class *) pointer to an area of memory
which can contain up to 'maxNumberOfClassesToReturn' Class records.
'objc_getClassList' will fill the area pointed to by 'returnValue'
with all the Classes registered with the runtime (or up to
maxNumberOfClassesToReturn if there are more than
maxNumberOfClassesToReturn). The function return value is the
number of classes actually returned in 'returnValue'. */
objc_EXPORT int objc_getClassList (Class *returnValue, int maxNumberOfClassesToReturn);
/* Compatibility Note: The Apple/NeXT runtime also has
Class objc_getFutureClass (const char *name);
void objc_setFutureClass (Class class_, const char *name);
the documentation is unclear on what they are supposed to do, and
the GNU Objective-C Runtime currently does not provide them. */
/* Return the name of the class 'class_', or the string "nil" if the
class_ is Nil. */
objc_EXPORT const char * class_getName (Class class_);
/* Return YES if 'class_' is a meta class, and NO if not. If 'class_'
is Nil, return NO. */
objc_EXPORT BOOL class_isMetaClass (Class class_);
/* Return the superclass of 'class_'. If 'class_' is Nil, or it is a
root class, return Nil. This function also works if 'class_' is a
class being constructed, that is, a class returned by
objc_allocateClassPair() but before it has been registered with the
runtime using objc_registerClassPair(). */
objc_EXPORT Class class_getSuperclass (Class class_);
/* Return the 'version' number of the class, which is an integer that
can be used to track changes in the class API, methods and
variables. If class_ is Nil, return 0. If class_ is not Nil, the
version is 0 unless class_setVersion() has been called to set a
different one.
Please note that internally the version is a long, but the API only
allows you to set and retrieve int values. */
objc_EXPORT int class_getVersion (Class class_);
/* Set the 'version' number of the class, which is an integer that can
be used to track changes in the class API, methods and variables.
If 'class_' is Nil, does nothing.
This is typically used internally by "Foundation" libraries such as
GNUstep Base to support serialization / deserialization of objects
that work across changes in the classes. If you are using such a
library, you probably want to use their versioning API, which may
be based on this one, but is integrated with the rest of the
library.
Please note that internally the version is a long, but the API only
allows you to set and retrieve int values. */
objc_EXPORT void class_setVersion (Class class_, int version);
/* Return the size in bytes (a byte is the size of a char) of an
instance of the class. If class_ is Nil, return 0; else it return
a non-zero number (since the 'isa' instance variable is required
for all classes). */
objc_EXPORT size_t class_getInstanceSize (Class class_);
/* Change the implementation of the method. It also searches all
classes for any class implementing the method, and replaces the
existing implementation with the new one. For that to work,
'method' must be a method returned by class_getInstanceMethod() or
class_getClassMethod() as the matching is done by comparing the
pointers; in that case, only the implementation in the class is
modified. Return the previous implementation that has been
replaced. If method or implementation is NULL, do nothing and
return NULL. */
objc_EXPORT IMP
method_setImplementation (Method method, IMP implementation);
/* Swap the implementation of two methods in a single, atomic
operation. This is equivalent to getting the implementation of
each method and then calling method_setImplementation() on the
other one. For this to work, the two methods must have been
returned by class_getInstanceMethod() or class_getClassMethod().
If 'method_a' or 'method_b' is NULL, do nothing. */
objc_EXPORT void
method_exchangeImplementations (Method method_a, Method method_b);
/* Create a new class/meta-class pair. This function is called to
create a new class at runtime. The class is created with
superclass 'superclass' (use 'Nil' to create a new root class) and
name 'class_name'. 'extraBytes' can be used to specify some extra
space for indexed variables to be added at the end of the class and
meta-class objects (it is recommended that you set extraBytes to
0). Once you have created the class, it is not usable yet. You
need to add any instance variables (by using class_addIvar()), any
instance methods (by using class_addMethod()) and any class methods
(by using class_addMethod() on the meta-class, as in
class_addMethod (object_getClass (class), method)) that are
required, and then you need to call objc_registerClassPair() to
activate the class. If you need to create a hierarchy of classes,
you need to create and register them one at a time. You cannot
create a new class using another class in construction as
superclass. Return Nil if 'class-name' is NULL or if a class with
that name already exists or 'superclass' is a class still in
construction.
Implementation Note: in the GNU runtime, allocating a class pair
only creates the structures for the class pair, but does not
register anything with the runtime. The class is registered with
the runtime only when objc_registerClassPair() is called. In
particular, if a class is in construction, objc_getClass() will not
find it, the superclass will not know about it,
class_getSuperclass() will return Nil and another thread may
allocate a class pair with the same name; the conflict will only be
detected when the classes are registered with the runtime.
*/
objc_EXPORT Class
objc_allocateClassPair (Class super_class, const char *class_name,
size_t extraBytes);
/* Register a class pair that was created with
objc_allocateClassPair(). After you register a class, you can no
longer make changes to its instance variables, but you can start
creating instances of it. Do nothing if 'class_' is NULL or if it
is not a class allocated by objc_allocateClassPair() and still in
construction. */
objc_EXPORT void
objc_registerClassPair (Class class_);
/* Dispose of a class pair created using objc_allocateClassPair().
Call this function if you started creating a new class with
objc_allocateClassPair() but then want to abort the process. You
should not access 'class_' after calling this method. Note that if
'class_' has already been registered with the runtime via
objc_registerClassPair(), this function does nothing; you can only
dispose of class pairs that are still being constructed. Do
nothing if class is 'Nil' or if 'class_' is not a class being
constructed. */
objc_EXPORT void
objc_disposeClassPair (Class class_);
/* Compatibility Note: The Apple/NeXT runtime has the function
objc_duplicateClass () but it's undocumented. The GNU runtime does
not have it. */
/** Implementation: the following functions are in sendmsg.c. */
/* Return the instance method with selector 'selector' of class
'class_', or NULL if the class (or one of its superclasses) does
not implement the method. Return NULL if class_ is Nil or selector
is NULL. Calling this function may trigger a call to
+resolveInstanceMethod:, but does not return a forwarding
function. */
objc_EXPORT Method class_getInstanceMethod (Class class_, SEL selector);
/* Return the class method with selector 'selector' of class 'class_',
or NULL if the class (or one of its superclasses) does not
implement the method. Return NULL if class_ is Nil or selector is
NULL. Calling this function may trigger a call to
+resolveClassMethod:, but does not return a forwarding
function. */
objc_EXPORT Method class_getClassMethod (Class class_, SEL selector);
/* Return the IMP (pointer to the function implementing a method) for
the instance method with selector 'selector' in class 'class_'.
This is the same routine that is used while messaging, and should
be very fast. Note that you most likely would need to cast the
return function pointer to a function pointer with the appropriate
arguments and return type before calling it. To get a class
method, you can pass the meta-class as the class_ argument (ie, use
class_getMethodImplementation (object_getClass (class_),
selector)). Return NULL if class_ is Nil or selector is NULL.
This function first looks for an existing method; if it is not
found, it calls +resolveClassMethod: or +resolveInstanceMethod:
(depending on whether a class or instance method is being looked
up) if it is implemented. If the method returns YES, then it tries
the look up again (the assumption being that +resolveClassMethod:
or resolveInstanceMethod: will add the method using
class_addMethod()). If it is still not found, it returns a
forwarding function. */
objc_EXPORT IMP class_getMethodImplementation (Class class_, SEL selector);
/* Compatibility Note: the Apple/NeXT runtime has the function
class_getMethodImplementation_stret () which currently does not
exist on the GNU runtime because the messaging implementation is
different. */
/* Return YES if class 'class_' has an instance method implementing
selector 'selector', and NO if not. Return NO if class_ is Nil or
selector is NULL. If you need to check a class method, use the
meta-class as the class_ argument (ie, use class_respondsToSelector
(object_getClass (class_), selector)). */
objc_EXPORT BOOL class_respondsToSelector (Class class_, SEL selector);
/* Add a method to a class. Use this function to add a new method to
a class (potentially overriding a method with the same selector in
the superclass); if you want to modify an existing method, use
method_setImplementation() instead (or class_replaceMethod ()).
This method adds an instance method to 'class_'; to add a class
method, get the meta class first, then add the method to the meta
class, that is, use
class_addMethod (object_getClass (class_), selector,
implementation, type);
Return YES if the method was added, and NO if not. Do nothing if
one of the arguments is NULL. */
objc_EXPORT BOOL class_addMethod (Class class_, SEL selector, IMP implementation,
const char *method_types);
/* Replace a method in a class. If the class already have a method
with this 'selector', find it and use method_setImplementation() to
replace the implementation with 'implementation' (method_types is
ignored in that case). If the class does not already have a method
with this 'selector', call 'class_addMethod() to add it.
Return the previous implementation of the method, or NULL if none
was found. Return NULL if any of the arguments is NULL. */
objc_EXPORT IMP class_replaceMethod (Class class_, SEL selector, IMP implementation,
const char *method_types);
/** Implementation: the following functions are in methods.c. */
/* Return the selector for method 'method'. Return NULL if 'method'
is NULL.
This function is misnamed; it should be called
'method_getSelector'. To get the actual name, get the selector,
then the name from the selector (ie, use sel_getName
(method_getName (method))). */
objc_EXPORT SEL method_getName (Method method);
/* Return the IMP of the method. Return NULL if 'method' is NULL. */
objc_EXPORT IMP method_getImplementation (Method method);
/* Return the type encoding of the method. Return NULL if 'method' is
NULL. */
objc_EXPORT const char * method_getTypeEncoding (Method method);
/* Return a method description for the method. Return NULL if
'method' is NULL. */
objc_EXPORT struct objc_method_description * method_getDescription (Method method);
/* Return all the instance methods of the class. The return value of
the function is a pointer to an area, allocated with malloc(), that
contains all the instance methods of the class. It does not
include instance methods of superclasses. The list is terminated
by NULL. Optionally, if you pass a non-NULL
'numberOfReturnedMethods' pointer, the unsigned int that it points
to will be filled with the number of instance methods returned. To
get the list of class methods, pass the meta-class in the 'class_'
argument, (ie, use class_copyMethodList (object_getClass (class_),
&numberOfReturnedMethods)). */
objc_EXPORT Method * class_copyMethodList (Class class_, unsigned int *numberOfReturnedMethods);
/** Implementation: the following functions are in encoding.c. */
/* Return the number of arguments that the method 'method' expects.
Note that all methods need two implicit arguments ('self' for the
receiver, and '_cmd' for the selector). Return 0 if 'method' is
NULL. */
objc_EXPORT unsigned int method_getNumberOfArguments (Method method);
/* Return the string encoding for the return type of method 'method'.
The string is a standard zero-terminated string in an area of
memory allocated with malloc(); you should free it with free() when
you finish using it. Return an empty string if method is NULL. */
objc_EXPORT char * method_copyReturnType (Method method);
/* Return the string encoding for the argument type of method
'method', argument number 'argumentNumber' ('argumentNumber' is 0
for self, 1 for _cmd, and 2 or more for the additional arguments if
any). The string is a standard zero-terminated string in an area
of memory allocated with malloc(); you should free it with free()
when you finish using it. Return an empty string if method is NULL
or if 'argumentNumber' refers to a non-existing argument. */
objc_EXPORT char * method_copyArgumentType (Method method, unsigned int argumentNumber);
/* Return the string encoding for the return type of method 'method'.
The string is returned by copying it into the supplied
'returnValue' string, which is of size 'returnValueSize'. No more
than 'returnValueSize' characters are copied; if the encoding is
smaller than 'returnValueSize', the rest of 'returnValue' is filled
with zeros. If it is bigger, it is truncated (and would not be
zero-terminated). You should supply a big enough
'returnValueSize'. If the method is NULL, returnValue is set to a
string of zeros. */
objc_EXPORT void method_getReturnType (Method method, char *returnValue,
size_t returnValueSize);
/* Return the string encoding for the argument type of method
'method', argument number 'argumentNumber' ('argumentNumber' is 0
for self, 1 for _cmd, and 2 or more for the additional arguments if
any). The string is returned by copying it into the supplied
'returnValue' string, which is of size 'returnValueSize'. No more
than 'returnValueSize' characters are copied; if the encoding is
smaller than 'returnValueSize', the rest of 'returnValue' is filled
with zeros. If it is bigger, it is truncated (and would not be
zero-terminated). You should supply a big enough
'returnValueSize'. If the method is NULL, returnValue is set to a
string of zeros. */
objc_EXPORT void method_getArgumentType (Method method, unsigned int argumentNumber,
char *returnValue, size_t returnValueSize);
/** Implementation: the following functions are in protocols.c. */
/* Return the protocol with name 'name', or nil if it the protocol is
not known to the runtime. */
objc_EXPORT Protocol *objc_getProtocol (const char *name);
/* Return all the protocols known to the runtime. The return value of
the function is a pointer to an area, allocated with malloc(), that
contains all the protocols known to the runtime; the list is
terminated by NULL. You should free this area using free() once
you no longer need it. Optionally, if you pass a non-NULL
'numberOfReturnedProtocols' pointer, the unsigned int that it
points to will be filled with the number of protocols returned. If
there are no protocols known to the runtime, NULL is returned. */
objc_EXPORT Protocol **objc_copyProtocolList (unsigned int *numberOfReturnedProtocols);
/* Add a protocol to a class, and return YES if it was done
successfully, and NO if not. At the moment, NO should only happen
if class_ or protocol are nil, if the protocol is not a Protocol
object or if the class already conforms to the protocol. */
objc_EXPORT BOOL class_addProtocol (Class class_, Protocol *protocol);
/* Return YES if the class 'class_' conforms to Protocol 'protocol',
and NO if not. This function does not check superclasses; if you
want to check for superclasses (in the way that [NSObject
+conformsToProtocol:] does) you need to iterate over the class
hierarchy using class_getSuperclass(), and call
class_conformsToProtocol() for each of them. */
objc_EXPORT BOOL class_conformsToProtocol (Class class_, Protocol *protocol);
/* Return all the protocols that the class conforms to. The return
value of the function is a pointer to an area, allocated with
malloc(), that contains all the protocols formally adopted by the
class. It does not include protocols adopted by superclasses. The
list is terminated by NULL. Optionally, if you pass a non-NULL
'numberOfReturnedProtocols' pointer, the unsigned int that it
points to will be filled with the number of protocols returned.
This function does not return protocols that superclasses conform
to. */
objc_EXPORT Protocol **class_copyProtocolList (Class class_, unsigned int *numberOfReturnedProtocols);
/* Return YES if protocol 'protocol' conforms to protocol
'anotherProtocol', and NO if not. Note that if one of the two
protocols is nil, it returns NO. */
objc_EXPORT BOOL protocol_conformsToProtocol (Protocol *protocol, Protocol *anotherProtocol);
/* Return YES if protocol 'protocol' is the same as protocol
'anotherProtocol', and 'NO' if not. Note that it returns YES if
the two protocols are both nil. */
objc_EXPORT BOOL protocol_isEqual (Protocol *protocol, Protocol *anotherProtocol);
/* Return the name of protocol 'protocol'. If 'protocol' is nil or is
not a Protocol, return NULL. */
objc_EXPORT const char *protocol_getName (Protocol *protocol);
/* Return the method description for the method with selector
'selector' in protocol 'protocol'; if 'requiredMethod' is YES, the
function searches the list of required methods; if NO, the list of
optional methods. If 'instanceMethod' is YES, the function search
for an instance method; if NO, for a class method. If there is no
matching method, an objc_method_description structure with both
name and types set to NULL is returned. This function will only
find methods that are directly declared in the protocol itself, not
in other protocols that this protocol adopts.
Note that the traditional ABI does not store the list of optional
methods of a protocol in a compiled module, so the traditional ABI
will always return (NULL, NULL) when requiredMethod == NO. */
objc_EXPORT struct objc_method_description protocol_getMethodDescription (Protocol *protocol,
SEL selector,
BOOL requiredMethod,
BOOL instanceMethod);
/* Return the method descriptions of all the methods of the protocol.
The return value of the function is a pointer to an area, allocated
with malloc(), that contains all the method descriptions of the
methods of the protocol. It does not recursively include methods
of the protocols adopted by this protocol. The list is terminated
by a NULL objc_method_description (one with both fields set to
NULL). Optionally, if you pass a non-NULL
'numberOfReturnedMethods' pointer, the unsigned int that it points
to will be filled with the number of properties returned.
Note that the traditional ABI does not store the list of optional
methods of a protocol in a compiled module, so the traditional ABI
will always return an empty list if requiredMethod is set to
NO. */
objc_EXPORT struct objc_method_description *protocol_copyMethodDescriptionList (Protocol *protocol,
BOOL requiredMethod,
BOOL instanceMethod,
unsigned int *numberOfReturnedMethods);
/* Return the property with name 'propertyName' of the protocol
'protocol'. If 'requiredProperty' is YES, the function searches
the list of required properties; if NO, the list of optional
properties. If 'instanceProperty' is YES, the function searches
the list of instance properties; if NO, the list of class
properties. At the moment, optional properties and class
properties are not part of the Objective-C language, so both
'requiredProperty' and 'instanceProperty' should be set to YES.
This function returns NULL if the required property cannot be
found.
Note that the traditional ABI does not store the list of properties
of a protocol in a compiled module, so the traditional ABI will
always return NULL. */
objc_EXPORT Property protocol_getProperty (Protocol *protocol, const char *propertyName,
BOOL requiredProperty, BOOL instanceProperty);
/* Return all the properties of the protocol. The return value of the
function is a pointer to an area, allocated with malloc(), that
contains all the properties of the protocol. It does not
recursively include properties of the protocols adopted by this
protocol. The list is terminated by NULL. Optionally, if you pass
a non-NULL 'numberOfReturnedProperties' pointer, the unsigned int
that it points to will be filled with the number of properties
returned.
Note that the traditional ABI does not store the list of properties
of a protocol in a compiled module, so the traditional ABI will
always return NULL and store 0 in numberOfReturnedProperties. */
objc_EXPORT Property *protocol_copyPropertyList (Protocol *protocol, unsigned int *numberOfReturnedProperties);
/* Return all the protocols that the protocol conforms to. The return
value of the function is a pointer to an area, allocated with
malloc(), that contains all the protocols formally adopted by the
protocol. It does not recursively include protocols adopted by the
protocols adopted by this protocol. The list is terminated by
NULL. Optionally, if you pass a non-NULL
'numberOfReturnedProtocols' pointer, the unsigned int that it
points to will be filled with the number of protocols returned. */
objc_EXPORT Protocol **protocol_copyProtocolList (Protocol *protocol, unsigned int *numberOfReturnedProtocols);
/** Implementation: the following hook is in init.c. */
/* This is a hook which is called by __objc_exec_class every time a
class or a category is loaded into the runtime. This may e.g. help
a dynamic loader determine the classes that have been loaded when
an object file is dynamically linked in. */
objc_EXPORT void (*_objc_load_callback)(Class _class, struct objc_category *category);
/** Implementation: the following functions are in objc-foreach.c. */
/* 'objc_enumerationMutation()' is called when a collection is
mutated while being "fast enumerated". That is a hard error, and
objc_enumerationMutation is called to deal with it. 'collection'
is the collection object that was mutated during an enumeration.
objc_enumerationMutation() will invoke the mutation handler if any
is set. Then, it will abort the program.
Compatibility note: the Apple runtime will not abort the program
after calling the mutation handler. */
objc_EXPORT void objc_enumerationMutation (id collection);
/* 'objc_set_enumeration_mutation_handler' can be used to set a
function that will be called (instead of aborting) when a fast
enumeration is mutated during enumeration. The handler will be
called with the 'collection' being mutated as the only argument and
it should not return; it should either exit the program, or could
throw an exception. The recommended implementation is to throw an
exception - the user can then use exception handlers to deal with
it.
This function is not thread safe (other threads may be trying to
invoke the enumeration mutation handler while you are changing it!)
and should be called during during the program initialization
before threads are started. It is mostly reserved for "Foundation"
libraries; in the case of GNUstep, GNUstep Base may be using this
function to improve the standard enumeration mutation handling.
You probably shouldn't use this function unless you are writing
your own Foundation library. */
objc_EXPORT void objc_setEnumerationMutationHandler (void (*handler)(id));
/* This structure (used during fast enumeration) is automatically
defined by the compiler (it is as if this definition was always
included in all Objective-C files). Note that it is usually
defined again with the name of NSFastEnumeration by "Foundation"
libraries such as GNUstep Base. And if NSFastEnumeration is
defined, the compiler will use it instead of
__objcFastEnumerationState when doing fast enumeration. */
/*
struct __objcFastEnumerationState
{
unsigned long state;
id *itemsPtr;
unsigned long *mutationsPtr;
unsigned long extra[5];
};
*/
/* Compatibility Note: The Apple/NeXT runtime has the functions
objc_copyImageNames (), class_getImageName () and
objc_copyClassNamesForImage () but they are undocumented. The GNU
runtime does not have them at the moment. */
/* Compatibility Note: The Apple/NeXT runtime has the functions
objc_setAssociatedObject (), objc_getAssociatedObject (),
objc_removeAssociatedObjects () and the objc_AssociationPolicy type
and related enum. The GNU runtime does not have them yet.
TODO: Implement them. */
/* Compatibility Note: The Apple/NeXT runtime has the function
objc_setForwardHandler (). The GNU runtime does not have it
because messaging (and, in particular, forwarding) works in a
different (incompatible) way with the GNU runtime. If you need to
customize message forwarding at the Objective-C runtime level (that
is, if you are implementing your own "Foundation" library such as
GNUstep Base on top of the Objective-C runtime), in objc/message.h
there are hooks (that work in the framework of the GNU runtime) to
do so. */
/** Implementation: the following functions are in memory.c. */
/* Traditional GNU Objective-C Runtime functions that are used for
memory allocation and disposal. These functions are used in the
same way as you use malloc, realloc, calloc and free and make sure
that memory allocation works properly with the garbage
collector.
Compatibility Note: these functions are not available with the
Apple/NeXT runtime. */
objc_EXPORT void *objc_malloc(size_t size);
/* FIXME: Shouldn't the following be called objc_malloc_atomic ? The
GC function is GC_malloc_atomic() which makes sense.
*/
objc_EXPORT void *objc_atomic_malloc(size_t size);
objc_EXPORT void *objc_realloc(void *mem, size_t size);
objc_EXPORT void *objc_calloc(size_t nelem, size_t size);
objc_EXPORT void objc_free(void *mem);
/** Implementation: the following functions are in gc.c. */
/* The GNU Objective-C Runtime has a different implementation of
garbage collection.
Compatibility Note: these functions are not available with the
Apple/NeXT runtime. */
/* Mark the instance variable as inaccessible to the garbage
collector. */
objc_EXPORT void class_ivar_set_gcinvisible (Class _class,
const char* ivarname,
BOOL gcInvisible);
/** Implementation: the following functions are in encoding.c. */
/* Traditional GNU Objective-C Runtime functions that are currently
used to implement method forwarding.
Compatibility Note: these functions are not available with the
Apple/NeXT runtime. */
/* Return the size of a variable which has the specified 'type'
encoding. */
objc_EXPORT int objc_sizeof_type (const char *type);
/* Return the align of a variable which has the specified 'type'
encoding. */
objc_EXPORT int objc_alignof_type (const char *type);
/* Return the aligned size of a variable which has the specified
'type' encoding. The aligned size is the size rounded up to the
nearest alignment. */
objc_EXPORT int objc_aligned_size (const char *type);
/* Return the promoted size of a variable which has the specified
'type' encoding. This is the size rounded up to the nearest
integral of the wordsize, taken to be the size of a void *. */
objc_EXPORT int objc_promoted_size (const char *type);
/* The following functions are used when parsing the type encoding of
methods, to skip over parts that are ignored. They take as
argument a pointer to a location inside the type encoding of a
method (which is a string) and return a new pointer, pointing to a
new location inside the string after having skipped the unwanted
information. */
/* Skip some type qualifiers (_C_CONST, _C_IN, etc). These may
eventually precede typespecs occurring in method prototype
encodings. */
objc_EXPORT const char *objc_skip_type_qualifiers (const char *type);
/* Skip one typespec element (_C_CLASS, _C_SEL, etc). If the typespec
is prepended by type qualifiers, these are skipped as well. */
objc_EXPORT const char *objc_skip_typespec (const char *type);
/* Skip an offset. */
objc_EXPORT const char *objc_skip_offset (const char *type);
/* Skip an argument specification (ie, skipping a typespec, which may
include qualifiers, and an offset too). */
objc_EXPORT const char *objc_skip_argspec (const char *type);
/* Read type qualifiers (_C_CONST, _C_IN, etc) from string 'type'
(stopping at the first non-type qualifier found) and return an
unsigned int which is the logical OR of all the corresponding flags
(_F_CONST, _F_IN etc). */
objc_EXPORT unsigned objc_get_type_qualifiers (const char *type);
/* Note that the following functions work for very simple structures,
but get easily confused by more complicated ones (for example,
containing vectors). A better solution is required. These
functions are likely to change in the next GCC release. */
/* The following three functions can be used to determine how a
structure is laid out by the compiler. For example:
struct objc_struct_layout layout;
int i;
objc_layout_structure (type, &layout);
while (objc_layout_structure_next_member (&layout))
{
int position, align;
const char *type;
objc_layout_structure_get_info (&layout, &position, &align, &type);
printf ("element %d has offset %d, alignment %d\n",
i++, position, align);
}
These functions are used by objc_sizeof_type and objc_alignof_type
functions to compute the size and alignment of structures. The
previous method of computing the size and alignment of a structure
was not working on some architectures, particularly on AIX, and in
the presence of bitfields inside the structure. */
struct objc_struct_layout
{
const char *original_type;
const char *type;
const char *prev_type;
unsigned int record_size;
unsigned int record_align;
};
objc_EXPORT void objc_layout_structure (const char *type,
struct objc_struct_layout *layout);
objc_EXPORT BOOL objc_layout_structure_next_member (struct objc_struct_layout *layout);
objc_EXPORT void objc_layout_finish_structure (struct objc_struct_layout *layout,
unsigned int *size,
unsigned int *align);
objc_EXPORT void objc_layout_structure_get_info (struct objc_struct_layout *layout,
unsigned int *offset,
unsigned int *align,
const char **type);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif
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