objc-proto.h

早期freebsd实现

/* Declare functions used within Objective C runtime support.
   Copyright (C) 1992 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC 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 2, or (at your option)
any later version.

GNU CC 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.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* As a special exception, if you link this library with files
   compiled with GCC to produce an executable, this does not cause
   the resulting executable to be covered by the GNU General Public License.
   This exception does not however invalidate any other reasons why
   the executable file might be covered by the GNU General Public License.  */
 

#ifndef __objc_proto_INCLUDE_GNU
#define __objc_proto_INCLUDE_GNU

/* This used to be #ifndef __OBJC__, but it turns out that
   object.m needs these declarations.  I don't understand why one
   might want to avoid them in object.m.  */

#if 1
/*
 * objc_getClass returns the id of the class 
 *  object for the aClassName class.   The class 
 *  object holds information used by instances of 
 *  the class.  
 *
 * Print a message to the standard error stream if 
 *  aClassName isn't part of the executable image.
 */
Class_t objc_getClass (const char *);

/*
 * objc_getMetaClass returns the id of the 
 *  meta class object for the aClassName class.  
 *  The meta class object holds information used 
 *  by the class object, just as the class 
 *  object holds information used by instances 
 *  of the class.  
 *
 * Print a message to the standard error stream 
 *  if aClassName isn't part of the executable image.
 */
MetaClass_t objc_getMetaClass (const char *);

/*
 * The compiler converts every message expression into a 
 *  call on one of these two functions.  Messages to 
 *  super are converted to calls on objc_msgSendSuper; 
 *  all others are converted to calls on objc_msgSend.
 *
 * These functions return the address of the method 
 *  implementation.  The compiler then generates calls
 *  to those methods passing the full argument array.
 *
 * Calls to objc_msgSend and objc_msgSendSuper 
 *  should be generated only by the compiler.  You shouldn't 
 *  call them directly in the Objective-C code you write.
 */
IMP objc_msgSend (id, SEL);

IMP objc_msgSendSuper (Super_t, SEL);
#endif

/*
 * Given the name of a variable within a class's 
 *  definition, return a pointer to a structure that
 *  describes it.
 */
Ivar_t object_getIvarAddress (id obj, const char *variableName);

/*
 * Given a class and a selector, return a pointer to the method's method
 * structure.  Return NULL if not found. 
 *
 * This is a method internal to the run-time. 
 */
Method_t searchForMethodInHierarchy (Class_t, SEL);


/*
 * The first function, sel_getUid, returns a selector that's 
 *  used at run time to identify the aName method.  Whenever 
 *  possible, you should use the @selector directive to 
 *  ask the compiler, rather than the run-time system, 
 *  to provide the selector for a method.  This function 
 *  should be used only if the name isn't known at compile 
 *  time.
 *
 * The second function, sel_getName, is the inverse 
 *  of the first.  It returns the name that was mapped to 
 *  aSelector.
 */
SEL sel_getUid (const STR);

const STR sel_getName (SEL);

/* 
 * This function returns the number of arguments that METHOD
 *  the takes.  This will be at least two, since it 
 *  includes the 猦idden