public/extend-lua-with-custom-c.html


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

<!doctype html><html lang=en-us><meta charset=utf-8><meta name=viewport content="width=device-width,initial-scale=1"><link href="data:image/x-icon;base64,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" rel=icon type=image/x-icon><title>Extend Lua with custom C functions using Clang</title><meta name=description content="Here is a boilerplate for extending Lua with custom C functions."><link rel=alternate type=application/rss+xml title="Mitja Felicijan's posts" href=https://mitjafelicijan.com/index.xml><link rel=alternate type=application/rss+xml title="Mitja Felicijan's notes" href=https://mitjafelicijan.com/notes.xml><style>body{padding:1rem;max-width:760px;background:#fff;font-family:times new roman,Times,serif;line-height:1.35rem}hr{margin-block-start:1.5rem}h1,h2,h3{line-height:initial}footer{margin-block-start:3rem}table{max-width:100%;border-collapse:separate;border-spacing:2px;border:1px solid #000;border-left:1px solid #999;border-top:1px solid #999}blockquote{font-style:italic}table thead{background:#eee}td,th{border:1px solid #000;padding:4px;border-right:1px solid #999;border-bottom:1px solid #999;text-align:left}pre{text-wrap:nowrap;overflow-x:auto;margin-block-start:1.5rem;margin-block-end:1.5rem;padding:.5rem 0;border-top:1px solid #000;border-bottom:1px solid #000}pre code{line-height:1.3em}pre,code,pre *,code *{font-family:monospace;font-size:initial!important}img,video,audio{max-width:100%}header{display:flex;flex-direction:row;gap:3rem}nav{display:flex;gap:.75rem}.pstatus-orange{background:gold}.pstatus-green{background:#9acd32}.pstatus-red{background:#cd5c5c}@media only screen and (max-width:600px){header{flex-direction:column;gap:1rem}a{word-wrap:break-word}}</style><header><nav class=main><a href=/>Home</a>
<a href=https://git.mitjafelicijan.com/ target=_blank>Git</a>
<a href=https://files.mitjafelicijan.com/ target=_blank>Files</a>
<a href=/mitjafelicijan.pgp.pub.txt target=_blank>PGP</a>
<a href=/curriculum-vitae.html>CV</a>
<a href=/index.xml target=_blank>RSS</a></nav></header><main><div><h1>Extend Lua with custom C functions using Clang</h1><p>May 23, 2023<div><p>Here is a boilerplate for extending Lua with custom C functions. This requires
Clang and Lua 5.1 to be installed. GCC can be used instead of Clang, but the
Makefile will need to be modified.<ul><li><p>nativefunc.c<pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:#00f>#include</span> <span style=color:#00f>&lt;lua.h&gt;</span><span style=color:#00f>
</span></span></span><span style=display:flex><span><span style=color:#00f>#include</span> <span style=color:#00f>&lt;lauxlib.h&gt;</span><span style=color:#00f>
</span></span></span><span style=display:flex><span><span style=color:#00f></span>
</span></span><span style=display:flex><span><span style=color:#00f>static</span> <span style=color:#2b91af>int</span> l_mult50(lua_State *L) {
</span></span><span style=display:flex><span>  <span style=color:#2b91af>double</span> number = luaL_checknumber(L, 1);
</span></span><span style=display:flex><span>  lua_pushnumber(L, number * 50);
</span></span><span style=display:flex><span>  <span style=color:#00f>return</span> 1;
</span></span><span style=display:flex><span>}
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:#2b91af>int</span> luaopen_nativefunc(lua_State *L) {
</span></span><span style=display:flex><span>  <span style=color:#00f>static</span> <span style=color:#00f>const</span> <span style=color:#00f>struct</span> luaL_Reg nativeFuncLib[] = {{<span style=color:#a31515>&#34;mult50&#34;</span>, l_mult50}, {NULL, NULL}};
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>  luaL_register(L, <span style=color:#a31515>&#34;nativelib&#34;</span>, nativeFuncLib);
</span></span><span style=display:flex><span>  <span style=color:#00f>return</span> 1;
</span></span><span style=display:flex><span>}
</span></span></code></pre><li><p>main.lua<pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>require <span style=color:#a31515>&#34;nativefunc&#34;</span>
</span></span><span style=display:flex><span>print(nativelib.mult50(50))
</span></span></code></pre><li><p>Makefile<pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span>CC       = clang
</span></span><span style=display:flex><span>CFLAGS   =
</span></span><span style=display:flex><span>INCLUDES = <span style=color:#a31515>`</span>pkg-config lua5.1 --cflags-only-I<span style=color:#a31515>`</span>
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>all:
</span></span><span style=display:flex><span>  <span style=color:#00f>$(</span>CC<span style=color:#00f>)</span> -shared -o nativefunc.so -fPIC nativefunc.c <span style=color:#00f>$(</span>CFLAGS<span style=color:#00f>)</span> <span style=color:#00f>$(</span>INCLUDES<span style=color:#00f>)</span>
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>clean:
</span></span><span style=display:flex><span>  rm *.so
</span></span></code></pre></ul></div></div></main><footer><hr><div><h3>Want to comment or have something to add?</h3>You can write me an email at
<a href=mailto:m@mitjafelicijan.com>m@mitjafelicijan.com</a> or catch up
with me
<a href=https://telegram.me/mitjafelicijan target=_blank>on Telegram</a>.</div><hr><p>This website does not track you. Content is made available under
the <a href=https://creativecommons.org/licenses/by/4.0/ target=_blank rel=noreferrer>CC BY 4.0 license</a> unless specified
otherwise. Blog feed is available as <a href=/index.xml target=_blank>RSS feed</a>.</footer><script src=https://cdn.usefathom.com/script.js data-site=XHQARKXP defer></script>