mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-24 19:52:54 +01:00
127 lines
6.3 KiB
HTML
127 lines
6.3 KiB
HTML
<?xml version="1.0" encoding="utf-8" ?>
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<meta name="generator" content="Docutils 0.5: http://docutils.sourceforge.net/" />
|
|
<title>Tutorial - Using LLVMC</title>
|
|
<link rel="stylesheet" href="llvm.css" type="text/css" />
|
|
</head>
|
|
<body>
|
|
<div class="document" id="tutorial-using-llvmc">
|
|
<h1 class="title">Tutorial - Using LLVMC</h1>
|
|
|
|
<!-- This file was automatically generated by rst2html.
|
|
Please do not edit directly!
|
|
The ReST source lives in the directory 'tools/llvmc/doc'. -->
|
|
<div class="contents topic" id="contents">
|
|
<p class="topic-title first">Contents</p>
|
|
<ul class="simple">
|
|
<li><a class="reference internal" href="#introduction" id="id1">Introduction</a></li>
|
|
<li><a class="reference internal" href="#compiling-with-llvmc" id="id2">Compiling with LLVMC</a></li>
|
|
<li><a class="reference internal" href="#using-llvmc-to-generate-toolchain-drivers" id="id3">Using LLVMC to generate toolchain drivers</a></li>
|
|
</ul>
|
|
</div>
|
|
<div class="doc_author">
|
|
<p>Written by <a href="mailto:foldr@codedgers.com">Mikhail Glushenkov</a></p>
|
|
</div><div class="section" id="introduction">
|
|
<h1><a class="toc-backref" href="#id1">Introduction</a></h1>
|
|
<p>LLVMC is a generic compiler driver, which plays the same role for LLVM
|
|
as the <tt class="docutils literal"><span class="pre">gcc</span></tt> program does for GCC - the difference being that LLVMC
|
|
is designed to be more adaptable and easier to customize. Most of
|
|
LLVMC functionality is implemented via plugins, which can be loaded
|
|
dynamically or compiled in. This tutorial describes the basic usage
|
|
and configuration of LLVMC.</p>
|
|
</div>
|
|
<div class="section" id="compiling-with-llvmc">
|
|
<h1><a class="toc-backref" href="#id2">Compiling with LLVMC</a></h1>
|
|
<p>In general, LLVMC tries to be command-line compatible with <tt class="docutils literal"><span class="pre">gcc</span></tt> as
|
|
much as possible, so most of the familiar options work:</p>
|
|
<pre class="literal-block">
|
|
$ llvmc -O3 -Wall hello.cpp
|
|
$ ./a.out
|
|
hello
|
|
</pre>
|
|
<p>This will invoke <tt class="docutils literal"><span class="pre">llvm-g++</span></tt> under the hood (you can see which
|
|
commands are executed by using the <tt class="docutils literal"><span class="pre">-v</span></tt> option). For further help on
|
|
command-line LLVMC usage, refer to the <tt class="docutils literal"><span class="pre">llvmc</span> <span class="pre">--help</span></tt> output.</p>
|
|
</div>
|
|
<div class="section" id="using-llvmc-to-generate-toolchain-drivers">
|
|
<h1><a class="toc-backref" href="#id3">Using LLVMC to generate toolchain drivers</a></h1>
|
|
<p>LLVMC plugins are written mostly using <a class="reference external" href="http://llvm.org/docs/TableGenFundamentals.html">TableGen</a>, so you need to
|
|
be familiar with it to get anything done.</p>
|
|
<p>Start by compiling <tt class="docutils literal"><span class="pre">example/Simple</span></tt>, which is a primitive wrapper for
|
|
<tt class="docutils literal"><span class="pre">gcc</span></tt>:</p>
|
|
<pre class="literal-block">
|
|
$ cd $LLVM_DIR/tools/llvmc
|
|
$ cp -r example/Simple plugins/Simple
|
|
|
|
# NB: A less verbose way to compile standalone LLVMC-based drivers is
|
|
# described in the reference manual.
|
|
|
|
$ make LLVMC_BASED_DRIVER_NAME=mygcc LLVMC_BUILTIN_PLUGINS=Simple
|
|
$ cat > hello.c
|
|
[...]
|
|
$ mygcc hello.c
|
|
$ ./hello.out
|
|
Hello
|
|
</pre>
|
|
<p>Here we link our plugin with the LLVMC core statically to form an executable
|
|
file called <tt class="docutils literal"><span class="pre">mygcc</span></tt>. It is also possible to build our plugin as a dynamic
|
|
library to be loaded by the <tt class="docutils literal"><span class="pre">llvmc</span></tt> executable (or any other LLVMC-based
|
|
standalone driver); this is described in the reference manual.</p>
|
|
<p>Contents of the file <tt class="docutils literal"><span class="pre">Simple.td</span></tt> look like this:</p>
|
|
<pre class="literal-block">
|
|
// Include common definitions
|
|
include "llvm/CompilerDriver/Common.td"
|
|
|
|
// Tool descriptions
|
|
def gcc : Tool<
|
|
[(in_language "c"),
|
|
(out_language "executable"),
|
|
(output_suffix "out"),
|
|
(cmd_line "gcc $INFILE -o $OUTFILE"),
|
|
(sink)
|
|
]>;
|
|
|
|
// Language map
|
|
def LanguageMap : LanguageMap<[LangToSuffixes<"c", ["c"]>]>;
|
|
|
|
// Compilation graph
|
|
def CompilationGraph : CompilationGraph<[Edge<"root", "gcc">]>;
|
|
</pre>
|
|
<p>As you can see, this file consists of three parts: tool descriptions,
|
|
language map, and the compilation graph definition.</p>
|
|
<p>At the heart of LLVMC is the idea of a compilation graph: vertices in
|
|
this graph are tools, and edges represent a transformation path
|
|
between two tools (for example, assembly source produced by the
|
|
compiler can be transformed into executable code by an assembler). The
|
|
compilation graph is basically a list of edges; a special node named
|
|
<tt class="docutils literal"><span class="pre">root</span></tt> is used to mark graph entry points.</p>
|
|
<p>Tool descriptions are represented as property lists: most properties
|
|
in the example above should be self-explanatory; the <tt class="docutils literal"><span class="pre">sink</span></tt> property
|
|
means that all options lacking an explicit description should be
|
|
forwarded to this tool.</p>
|
|
<p>The <tt class="docutils literal"><span class="pre">LanguageMap</span></tt> associates a language name with a list of suffixes
|
|
and is used for deciding which toolchain corresponds to a given input
|
|
file.</p>
|
|
<p>To learn more about LLVMC customization, refer to the reference
|
|
manual and plugin source code in the <tt class="docutils literal"><span class="pre">plugins</span></tt> directory.</p>
|
|
<hr />
|
|
<address>
|
|
<a href="http://jigsaw.w3.org/css-validator/check/referer">
|
|
<img src="http://jigsaw.w3.org/css-validator/images/vcss-blue"
|
|
alt="Valid CSS" /></a>
|
|
<a href="http://validator.w3.org/check?uri=referer">
|
|
<img src="http://www.w3.org/Icons/valid-xhtml10-blue"
|
|
alt="Valid XHTML 1.0 Transitional"/></a>
|
|
|
|
<a href="mailto:foldr@codedgers.com">Mikhail Glushenkov</a><br />
|
|
<a href="http://llvm.org">LLVM Compiler Infrastructure</a><br />
|
|
|
|
Last modified: $Date: 2008-12-11 11:34:48 -0600 (Thu, 11 Dec 2008) $
|
|
</address></div>
|
|
</div>
|
|
</body>
|
|
</html>
|