152 lines
6.2 KiB
Objective-C
152 lines
6.2 KiB
Objective-C
/* Basic data types for Objective C.
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Copyright (C) 1993-2019 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef __objc_INCLUDE_GNU
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#define __objc_INCLUDE_GNU
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/* This file contains the definition of the basic types used by the
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Objective-C language. It needs to be included to do almost
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anything with Objective-C. */
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <stddef.h>
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/* The current version of the GNU Objective-C Runtime library in
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compressed ISO date format. This should be updated any time a new
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version is released with changes to the public API (there is no
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need to update it if there were no API changes since the previous
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release). This macro is only defined starting with the GNU
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Objective-C Runtime shipped with GCC 4.6.0. If it is not defined,
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it is either an older version of the runtime, or another runtime. */
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#define __GNU_LIBOBJC__ 20110608
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/* Definition of the boolean type.
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Compatibility note: the Apple/NeXT runtime defines a BOOL as a
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'signed char'. The GNU runtime uses an 'unsigned char'.
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Important: this could change and we could switch to 'typedef bool
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BOOL' in the future. Do not depend on the type of BOOL. */
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#undef BOOL
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typedef unsigned char BOOL;
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#define YES (BOOL)1
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#define NO (BOOL)0
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/* The basic Objective-C types (SEL, Class, id) are defined as pointer
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to opaque structures. The details of the structures are private to
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the runtime and may potentially change from one version to the
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other. */
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/* A SEL (selector) represents an abstract method (in the
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object-oriented sense) and includes all the details of how to
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invoke the method (which means its name, arguments and return
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types) but provides no implementation of its own. You can check
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whether a class implements a selector or not, and if you have a
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selector and know that the class implements it, you can use it to
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call the method for an object in the class. */
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typedef const struct objc_selector *SEL;
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/* A Class is a class (in the object-oriented sense). In Objective-C
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there is the complication that each Class is an object itself, and
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so belongs to a class too. This class that a class belongs to is
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called its 'meta class'. */
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typedef struct objc_class *Class;
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/* An 'id' is an object of an unknown class. The way the object data
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is stored inside the object is private and what you see here is
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only the beginning of the actual struct. The first field is always
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a pointer to the Class that the object belongs to. */
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typedef struct objc_object
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{
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/* 'class_pointer' is the Class that the object belongs to. In case
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of a Class object, this pointer points to the meta class.
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Compatibility Note: The Apple/NeXT runtime calls this field
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'isa'. To access this field, use object_getClass() from
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runtime.h, which is an inline function so does not add any
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overhead and is also portable to other runtimes. */
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Class class_pointer;
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} *id;
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/* 'IMP' is a C function that implements a method. When retrieving
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the implementation of a method from the runtime, this is the type
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of the pointer returned. The idea of the definition of IMP is to
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represent a 'pointer to a general function taking an id, a SEL,
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followed by other unspecified arguments'. You must always cast an
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IMP to a pointer to a function taking the appropriate, specific
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types for that function, before calling it - to make sure the
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appropriate arguments are passed to it. The code generated by the
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compiler to perform method calls automatically does this cast
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inside method calls. */
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typedef id (*IMP)(id, SEL, ...);
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/* 'nil' is the null object. Messages to nil do nothing and always
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return 0. */
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#define nil (id)0
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/* 'Nil' is the null class. Since classes are objects too, this is
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actually the same object as 'nil' (and behaves in the same way),
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but it has a type of Class, so it is good to use it instead of
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'nil' if you are comparing a Class object to nil as it enables the
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compiler to do some type-checking. */
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#define Nil (Class)0
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/* TODO: Move the 'Protocol' declaration into objc/runtime.h. A
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Protocol is simply an object, not a basic Objective-C type. The
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Apple runtime defines Protocol in objc/runtime.h too, so it's good
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to move it there for API compatibility. */
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/* A 'Protocol' is a formally defined list of selectors (normally
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created using the @protocol Objective-C syntax). It is mostly used
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at compile-time to check that classes implement all the methods
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that they are supposed to. Protocols are also available in the
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runtime system as Protocol objects. */
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#ifndef __OBJC__
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/* Once we stop including the deprecated struct_objc_protocol.h
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there is no reason to even define a 'struct objc_protocol'. As
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all the structure details will be hidden, a Protocol basically is
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simply an object (as it should be). */
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typedef struct objc_object Protocol;
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#else /* __OBJC__ */
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@class Protocol;
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#endif
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/* Compatibility note: the Apple/NeXT runtime defines sel_getName(),
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sel_registerName(), object_getClassName(), object_getIndexedIvars()
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in this file while the GNU runtime defines them in runtime.h.
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The reason the GNU runtime does not define them here is that they
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are not basic Objective-C types (defined in this file), but are
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part of the runtime API (defined in runtime.h). */
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#ifdef __cplusplus
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}
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#endif
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#endif /* not __objc_INCLUDE_GNU */
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