mirror of https://github.com/axmolengine/axmol.git
188 lines
5.9 KiB
HTML
188 lines
5.9 KiB
HTML
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
|
||
|
|
<html>
|
||
|
|
<head>
|
||
|
|
<title>Lua/C API Extensions</title>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
||
|
|
<meta name="Author" content="Mike Pall">
|
||
|
|
<meta name="Copyright" content="Copyright (C) 2005-2013, Mike Pall">
|
||
|
|
<meta name="Language" content="en">
|
||
|
|
<link rel="stylesheet" type="text/css" href="bluequad.css" media="screen">
|
||
|
|
<link rel="stylesheet" type="text/css" href="bluequad-print.css" media="print">
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div id="site">
|
||
|
|
<a href="http://luajit.org"><span>Lua<span id="logo">JIT</span></span></a>
|
||
|
|
</div>
|
||
|
|
<div id="head">
|
||
|
|
<h1>Lua/C API Extensions</h1>
|
||
|
|
</div>
|
||
|
|
<div id="nav">
|
||
|
|
<ul><li>
|
||
|
|
<a href="luajit.html">LuaJIT</a>
|
||
|
|
<ul><li>
|
||
|
|
<a href="http://luajit.org/download.html">Download <span class="ext">»</span></a>
|
||
|
|
</li><li>
|
||
|
|
<a href="install.html">Installation</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="running.html">Running</a>
|
||
|
|
</li></ul>
|
||
|
|
</li><li>
|
||
|
|
<a href="extensions.html">Extensions</a>
|
||
|
|
<ul><li>
|
||
|
|
<a href="ext_ffi.html">FFI Library</a>
|
||
|
|
<ul><li>
|
||
|
|
<a href="ext_ffi_tutorial.html">FFI Tutorial</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="ext_ffi_api.html">ffi.* API</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="ext_ffi_semantics.html">FFI Semantics</a>
|
||
|
|
</li></ul>
|
||
|
|
</li><li>
|
||
|
|
<a href="ext_jit.html">jit.* Library</a>
|
||
|
|
</li><li>
|
||
|
|
<a class="current" href="ext_c_api.html">Lua/C API</a>
|
||
|
|
</li></ul>
|
||
|
|
</li><li>
|
||
|
|
<a href="status.html">Status</a>
|
||
|
|
<ul><li>
|
||
|
|
<a href="changes.html">Changes</a>
|
||
|
|
</li></ul>
|
||
|
|
</li><li>
|
||
|
|
<a href="faq.html">FAQ</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="http://luajit.org/performance.html">Performance <span class="ext">»</span></a>
|
||
|
|
</li><li>
|
||
|
|
<a href="http://wiki.luajit.org/">Wiki <span class="ext">»</span></a>
|
||
|
|
</li><li>
|
||
|
|
<a href="http://luajit.org/list.html">Mailing List <span class="ext">»</span></a>
|
||
|
|
</li></ul>
|
||
|
|
</div>
|
||
|
|
<div id="main">
|
||
|
|
<p>
|
||
|
|
LuaJIT adds some extensions to the standard Lua/C API. The LuaJIT include
|
||
|
|
directory must be in the compiler search path (<tt>-I<i>path</i></tt>)
|
||
|
|
to be able to include the required header for C code:
|
||
|
|
</p>
|
||
|
|
<pre class="code">
|
||
|
|
#include "luajit.h"
|
||
|
|
</pre>
|
||
|
|
<p>
|
||
|
|
Or for C++ code:
|
||
|
|
</p>
|
||
|
|
<pre class="code">
|
||
|
|
#include "lua.hpp"
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<h2 id="luaJIT_setmode"><tt>luaJIT_setmode(L, idx, mode)</tt>
|
||
|
|
— Control VM</h2>
|
||
|
|
<p>
|
||
|
|
This is a C API extension to allow control of the VM from C code. The
|
||
|
|
full prototype of <tt>LuaJIT_setmode</tt> is:
|
||
|
|
</p>
|
||
|
|
<pre class="code">
|
||
|
|
LUA_API int luaJIT_setmode(lua_State *L, int idx, int mode);
|
||
|
|
</pre>
|
||
|
|
<p>
|
||
|
|
The returned status is either success (<tt>1</tt>) or failure (<tt>0</tt>).
|
||
|
|
The second argument is either <tt>0</tt> or a stack index (similar to the
|
||
|
|
other Lua/C API functions).
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
The third argument specifies the mode, which is 'or'ed with a flag.
|
||
|
|
The flag can be <tt>LUAJIT_MODE_OFF</tt> to turn a feature on,
|
||
|
|
<tt>LUAJIT_MODE_ON</tt> to turn a feature off, or
|
||
|
|
<tt>LUAJIT_MODE_FLUSH</tt> to flush cached code.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
The following modes are defined:
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<h3 id="mode_engine"><tt>luaJIT_setmode(L, 0, LUAJIT_MODE_ENGINE|flag)</tt></h3>
|
||
|
|
<p>
|
||
|
|
Turn the whole JIT compiler on or off or flush the whole cache of compiled code.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<h3 id="mode_func"><tt>luaJIT_setmode(L, idx, LUAJIT_MODE_FUNC|flag)</tt><br>
|
||
|
|
<tt>luaJIT_setmode(L, idx, LUAJIT_MODE_ALLFUNC|flag)</tt><br>
|
||
|
|
<tt>luaJIT_setmode(L, idx, LUAJIT_MODE_ALLSUBFUNC|flag)</tt></h3>
|
||
|
|
<p>
|
||
|
|
This sets the mode for the function at the stack index <tt>idx</tt> or
|
||
|
|
the parent of the calling function (<tt>idx = 0</tt>). It either
|
||
|
|
enables JIT compilation for a function, disables it and flushes any
|
||
|
|
already compiled code or only flushes already compiled code. This
|
||
|
|
applies recursively to all sub-functions of the function with
|
||
|
|
<tt>LUAJIT_MODE_ALLFUNC</tt> or only to the sub-functions with
|
||
|
|
<tt>LUAJIT_MODE_ALLSUBFUNC</tt>.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<h3 id="mode_trace"><tt>luaJIT_setmode(L, trace,<br>
|
||
|
|
LUAJIT_MODE_TRACE|LUAJIT_MODE_FLUSH)</tt></h3>
|
||
|
|
<p>
|
||
|
|
Flushes the specified root trace and all of its side traces from the cache.
|
||
|
|
The code for the trace will be retained as long as there are any other
|
||
|
|
traces which link to it.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<h3 id="mode_wrapcfunc"><tt>luaJIT_setmode(L, idx, LUAJIT_MODE_WRAPCFUNC|flag)</tt></h3>
|
||
|
|
<p>
|
||
|
|
This mode defines a wrapper function for calls to C functions. If
|
||
|
|
called with <tt>LUAJIT_MODE_ON</tt>, the stack index at <tt>idx</tt>
|
||
|
|
must be a <tt>lightuserdata</tt> object holding a pointer to the wrapper
|
||
|
|
function. From now on all C functions are called through the wrapper
|
||
|
|
function. If called with <tt>LUAJIT_MODE_OFF</tt> this mode is turned
|
||
|
|
off and all C functions are directly called.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
The wrapper function can be used for debugging purposes or to catch
|
||
|
|
and convert foreign exceptions. But please read the section on
|
||
|
|
<a href="extensions.html#exceptions">C++ exception interoperability</a>
|
||
|
|
first. Recommended usage can be seen in this C++ code excerpt:
|
||
|
|
</p>
|
||
|
|
<pre class="code">
|
||
|
|
#include <exception>
|
||
|
|
#include "lua.hpp"
|
||
|
|
|
||
|
|
// Catch C++ exceptions and convert them to Lua error messages.
|
||
|
|
// Customize as needed for your own exception classes.
|
||
|
|
static int wrap_exceptions(lua_State *L, lua_CFunction f)
|
||
|
|
{
|
||
|
|
try {
|
||
|
|
return f(L); // Call wrapped function and return result.
|
||
|
|
} catch (const char *s) { // Catch and convert exceptions.
|
||
|
|
lua_pushstring(L, s);
|
||
|
|
} catch (std::exception& e) {
|
||
|
|
lua_pushstring(L, e.what());
|
||
|
|
} catch (...) {
|
||
|
|
lua_pushliteral(L, "caught (...)");
|
||
|
|
}
|
||
|
|
return lua_error(L); // Rethrow as a Lua error.
|
||
|
|
}
|
||
|
|
|
||
|
|
static int myinit(lua_State *L)
|
||
|
|
{
|
||
|
|
...
|
||
|
|
// Define wrapper function and enable it.
|
||
|
|
lua_pushlightuserdata(L, (void *)wrap_exceptions);
|
||
|
|
luaJIT_setmode(L, -1, LUAJIT_MODE_WRAPCFUNC|LUAJIT_MODE_ON);
|
||
|
|
lua_pop(L, 1);
|
||
|
|
...
|
||
|
|
}
|
||
|
|
</pre>
|
||
|
|
<p>
|
||
|
|
Note that you can only define <b>a single global wrapper function</b>,
|
||
|
|
so be careful when using this mechanism from multiple C++ modules.
|
||
|
|
Also note that this mechanism is not without overhead.
|
||
|
|
</p>
|
||
|
|
<br class="flush">
|
||
|
|
</div>
|
||
|
|
<div id="foot">
|
||
|
|
<hr class="hide">
|
||
|
|
Copyright © 2005-2013 Mike Pall
|
||
|
|
<span class="noprint">
|
||
|
|
·
|
||
|
|
<a href="contact.html">Contact</a>
|
||
|
|
</span>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|