From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libobjc/objc/message.h | 141 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 libobjc/objc/message.h (limited to 'libobjc/objc/message.h') diff --git a/libobjc/objc/message.h b/libobjc/objc/message.h new file mode 100644 index 000000000..8d03fefe4 --- /dev/null +++ b/libobjc/objc/message.h @@ -0,0 +1,141 @@ +/* GNU Objective C Runtime messaging declarations + Copyright (C) 1993, 1995, 1996, 2004, 2009, + 2010 Free Software Foundation, Inc. + +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 +. */ + +#ifndef __objc_message_INCLUDE_GNU +#define __objc_message_INCLUDE_GNU + +#include "objc.h" +#include "objc-decls.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* This file includes declarations of the messaging functions and + types. */ + +/* Compatibility note: the messaging function is one area where the + GNU runtime and the Apple/NeXT runtime differ significantly. If + you can, it is recommended that you use higher-level facilities + (provided by a Foundation library such as GNUstep Base) to perform + forwarding or other advanced messaging tricks. */ + +/* This function returns the IMP (C function implementing a method) to + use to invoke the method with selector 'op' of receiver 'receiver'. + + This is the function used by the compiler when compiling method + invocations with the GNU runtime. For example, the method call + + result = [receiver method]; + + is compiled by the compiler (with the GNU runtime) into the + equivalent of: + + { + IMP function = objc_msg_lookup (receiver, @selector (method)); + result = function (receiver, @selector (method)); + } + + so, a call to objc_msg_lookup() determines the IMP (the C function + implementing the method) to call. Then, the function is called. + If the method takes or returns different arguments, the compiler + will cast 'function' to the right type before invoking it, making + sure arguments and return value are handled correctly. + + objc_msg_lookup() must always return a valid function that can be + called with the required method signature (otherwise the + compiler-generated code shown above could segfault). If 'receiver' + is NULL, objc_msg_lookup() returns a C function that does nothing, + ignores all its arguments, and returns NULL (see nil_method.c). If + 'receiver' does not respond to the selector 'op', objc_msg_lookup() + will try to call +resolveClassMethod: or resolveInstanceMethod: as + appropriate, and if they return YES, it will try the lookup again + (+resolveClassMethod: and +resolveInstanceMethod: can thus install + dynamically methods as they are requested). If + +resolveClassMethod: or +resolveInstanceMethod: are either not + available, or return NO, or return YES but 'receiver' still doesn't + implement the 'selector' after calling them, the runtime returns a + generic "forwarding" function that can be called with the required + method signature and which can process the method invocation + according to the forwarding API. There are two runtime hooks that + allow Foundation libraries (such as GNUstep-Base) to return their + own forwarding function in preference to the runtime ones. When + that happens, the Foundation library effectively takes complete + control of the forwarding process; any method invocation where the + selector is not implemented by the receiver will end up calling a + forwarding function chosen by the Foundation library. */ +objc_EXPORT IMP objc_msg_lookup (id receiver, SEL op); + +/* Structure used when a message is send to a class's super class. + The compiler generates one of these structures and passes it to + objc_msg_lookup_super() when a [super method] call is compiled. */ + +/* In the traditional API, the super class field is called 'class' in + Objective-C and 'super_class' in Objective-C++. In the new API + (objc/runtime.h) it is always called 'super_class'. We detect the + "traditional API" by the fact that the objc/objc-api.h header + include guards are defined, which means objc/objc-api.h has been + included. This works because objc/message.h does not exist in the + Traditional API and is only read because objc-api.h itself includes + it. */ +#ifdef __objc_api_INCLUDE_GNU +/* Traditional API. */ +typedef struct objc_super +{ + id self; /* Id of the object sending the message. */ +#ifdef __cplusplus + Class super_class; +#else + Class class; /* Object's super class. */ +#endif +} Super, *Super_t; +#else +/* Modern API. */ +struct objc_super +{ + id self; /* The receiver of the message. */ + Class super_class; /* The superclass of the receiver. */ +}; +#endif + +/* This is used by the compiler instead of objc_msg_lookup () when + compiling a call to 'super', such as [super method]. This requires + sending a message to super->self, but looking up the method as if + super->self was in class super->super_class. */ +objc_EXPORT IMP objc_msg_lookup_super (struct objc_super *super, SEL sel); + +/* Hooks for method forwarding. They make it easy to substitute the + built-in forwarding with one based on a library, such as ffi, that + implement closures, thereby avoiding gcc's __builtin_apply + problems. __objc_msg_forward2's result will be preferred over that + of __objc_msg_forward if both are set and return non-NULL. */ +objc_EXPORT IMP (*__objc_msg_forward)(SEL); +objc_EXPORT IMP (*__objc_msg_forward2)(id, SEL); + +#ifdef __cplusplus +} +#endif + +#endif /* not __objc_message_INCLUDE_GNU */ -- cgit v1.2.3