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| author | Craig Jennings <c@cjennings.net> | 2024-04-07 13:41:34 -0500 |
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| committer | Craig Jennings <c@cjennings.net> | 2024-04-07 13:41:34 -0500 |
| commit | 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 (patch) | |
| tree | f1190704f78f04a2b0b4c977d20fe96a828377f1 /devdocs/gcc~13/messaging-with-the-gnu-objective-c-runtime.html | |
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diff --git a/devdocs/gcc~13/messaging-with-the-gnu-objective-c-runtime.html b/devdocs/gcc~13/messaging-with-the-gnu-objective-c-runtime.html new file mode 100644 index 00000000..84f4b828 --- /dev/null +++ b/devdocs/gcc~13/messaging-with-the-gnu-objective-c-runtime.html @@ -0,0 +1,6 @@ +<div class="section-level-extent" id="Messaging-with-the-GNU-Objective-C-runtime"> <div class="nav-panel"> <p> Previous: <a href="fast-enumeration" accesskey="p" rel="prev">Fast Enumeration</a>, Up: <a href="objective-c" accesskey="u" rel="up">GNU Objective-C Features</a> [<a href="index#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="indices" title="Index" rel="index">Index</a>]</p> </div> <h1 class="section" id="Messaging-with-the-GNU-Objective-C-Runtime"><span>8.10 Messaging with the GNU Objective-C Runtime<a class="copiable-link" href="#Messaging-with-the-GNU-Objective-C-Runtime"> ΒΆ</a></span></h1> <p>This section is specific for the GNU Objective-C runtime. If you are using a different runtime, you can skip it. </p> <p>The implementation of messaging in the GNU Objective-C runtime is designed to be portable, and so is based on standard C. </p> <p>Sending a message in the GNU Objective-C runtime is composed of two separate steps. First, there is a call to the lookup function, <code class="code">objc_msg_lookup ()</code> (or, in the case of messages to super, <code class="code">objc_msg_lookup_super ()</code>). This runtime function takes as argument the receiver and the selector of the method to be called; it returns the <code class="code">IMP</code>, that is a pointer to the function implementing the method. The second step of method invocation consists of casting this pointer function to the appropriate function pointer type, and calling the function pointed to it with the right arguments. </p> <p>For example, when the compiler encounters a method invocation such as <code class="code">[object init]</code>, it compiles it into a call to <code class="code">objc_msg_lookup (object, @selector(init))</code> followed by a cast of the returned value to the appropriate function pointer type, and then it calls it. </p> <ul class="mini-toc"> <li><a href="dynamically-registering-methods" accesskey="1">Dynamically Registering Methods</a></li> <li><a href="forwarding-hook" accesskey="2">Forwarding Hook</a></li> </ul> </div><div class="_attribution"> + <p class="_attribution-p"> + © Free Software Foundation<br>Licensed under the GNU Free Documentation License, Version 1.3.<br> + <a href="https://gcc.gnu.org/onlinedocs/gcc-13.1.0/gcc/Messaging-with-the-GNU-Objective-C-runtime.html" class="_attribution-link">https://gcc.gnu.org/onlinedocs/gcc-13.1.0/gcc/Messaging-with-the-GNU-Objective-C-runtime.html</a> + </p> +</div> |