<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 0.4.1: http://docutils.sourceforge.net/" />
+<meta name="generator" content="Docutils 0.6: http://docutils.sourceforge.net/" />
<title>Customizing LLVMC: Reference Manual</title>
<link rel="stylesheet" href="llvm.css" type="text/css" />
</head>
<body>
<div class="document" id="customizing-llvmc-reference-manual">
<h1 class="title">Customizing LLVMC: Reference Manual</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">
-<p class="topic-title first"><a id="contents" name="contents">Contents</a></p>
+<div class="contents topic" id="contents">
+<p class="topic-title first">Contents</p>
<ul class="simple">
-<li><a class="reference" href="#introduction" id="id4" name="id4">Introduction</a></li>
-<li><a class="reference" href="#compiling-with-llvmc" id="id5" name="id5">Compiling with LLVMC</a></li>
-<li><a class="reference" href="#predefined-options" id="id6" name="id6">Predefined options</a></li>
-<li><a class="reference" href="#compiling-llvmc-plugins" id="id7" name="id7">Compiling LLVMC plugins</a></li>
-<li><a class="reference" href="#customizing-llvmc-the-compilation-graph" id="id8" name="id8">Customizing LLVMC: the compilation graph</a></li>
-<li><a class="reference" href="#describing-options" id="id9" name="id9">Describing options</a><ul>
-<li><a class="reference" href="#external-options" id="id10" name="id10">External options</a></li>
-</ul>
-</li>
-<li><a class="reference" href="#conditional-evaluation" id="id11" name="id11">Conditional evaluation</a></li>
-<li><a class="reference" href="#writing-a-tool-description" id="id12" name="id12">Writing a tool description</a><ul>
-<li><a class="reference" href="#actions" id="id13" name="id13">Actions</a></li>
+<li><a class="reference internal" href="#introduction" id="id7">Introduction</a></li>
+<li><a class="reference internal" href="#compiling-with-llvmc" id="id8">Compiling with <tt class="docutils literal">llvmc</tt></a></li>
+<li><a class="reference internal" href="#predefined-options" id="id9">Predefined options</a></li>
+<li><a class="reference internal" href="#compiling-llvmc-based-drivers" id="id10">Compiling LLVMC-based drivers</a></li>
+<li><a class="reference internal" href="#customizing-llvmc-the-compilation-graph" id="id11">Customizing LLVMC: the compilation graph</a></li>
+<li><a class="reference internal" href="#describing-options" id="id12">Describing options</a></li>
+<li><a class="reference internal" href="#conditional-evaluation" id="id13">Conditional evaluation</a></li>
+<li><a class="reference internal" href="#writing-a-tool-description" id="id14">Writing a tool description</a><ul>
+<li><a class="reference internal" href="#id4" id="id15">Actions</a></li>
</ul>
</li>
-<li><a class="reference" href="#language-map" id="id14" name="id14">Language map</a></li>
-<li><a class="reference" href="#more-advanced-topics" id="id15" name="id15">More advanced topics</a><ul>
-<li><a class="reference" href="#hooks-and-environment-variables" id="id16" name="id16">Hooks and environment variables</a></li>
-<li><a class="reference" href="#how-plugins-are-loaded" id="id17" name="id17">How plugins are loaded</a></li>
-<li><a class="reference" href="#debugging" id="id18" name="id18">Debugging</a></li>
+<li><a class="reference internal" href="#language-map" id="id16">Language map</a></li>
+<li><a class="reference internal" href="#option-preprocessor" id="id17">Option preprocessor</a></li>
+<li><a class="reference internal" href="#more-advanced-topics" id="id18">More advanced topics</a><ul>
+<li><a class="reference internal" href="#hooks-and-environment-variables" id="id19">Hooks and environment variables</a></li>
+<li><a class="reference internal" href="#debugging" id="id20">Debugging</a></li>
+<li><a class="reference internal" href="#conditioning-on-the-executable-name" id="id21">Conditioning on the executable name</a></li>
</ul>
</li>
</ul>
</div>
<div class="doc_author">
<p>Written by <a href="mailto:foldr@codedgers.com">Mikhail Glushenkov</a></p>
-</div><div class="section">
-<h1><a class="toc-backref" href="#id4" id="introduction" name="introduction">Introduction</a></h1>
+</div><div class="section" id="introduction">
+<h1><a class="toc-backref" href="#id7">Introduction</a></h1>
<p>LLVMC is a generic compiler driver, designed to be customizable and
-extensible. It plays the same role for LLVM as the <tt class="docutils literal"><span class="pre">gcc</span></tt> program
-does for GCC - LLVMC's job is essentially to transform a set of input
-files into a set of targets depending on configuration rules and user
-options. What makes LLVMC different is that these transformation rules
-are completely customizable - in fact, LLVMC knows nothing about the
-specifics of transformation (even the command-line options are mostly
-not hard-coded) and regards the transformation structure as an
-abstract graph. The structure of this graph is completely determined
-by plugins, which can be either statically or dynamically linked. This
-makes it possible to easily adapt LLVMC for other purposes - for
-example, as a build tool for game resources.</p>
-<p>Because LLVMC employs <a class="reference" href="http://llvm.cs.uiuc.edu/docs/TableGenFundamentals.html">TableGen</a> as its configuration language, you
+extensible. It plays the same role for LLVM as the <tt class="docutils literal">gcc</tt> program does for
+GCC - LLVMC's job is essentially to transform a set of input files into a set of
+targets depending on configuration rules and user options. What makes LLVMC
+different is that these transformation rules are completely customizable - in
+fact, LLVMC knows nothing about the specifics of transformation (even the
+command-line options are mostly not hard-coded) and regards the transformation
+structure as an abstract graph. The structure of this graph is described in
+high-level TableGen code, from which an efficient C++ representation is
+automatically derived. This makes it possible to adapt LLVMC for other
+purposes - for example, as a build tool for game resources.</p>
+<p>Because LLVMC employs <a class="reference external" href="http://llvm.org/docs/TableGenFundamentals.html">TableGen</a> as its configuration language, you
need to be familiar with it to customize LLVMC.</p>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id5" id="compiling-with-llvmc" name="compiling-with-llvmc">Compiling with LLVMC</a></h1>
-<p>LLVMC tries hard to be as compatible with <tt class="docutils literal"><span class="pre">gcc</span></tt> as possible,
+<div class="section" id="compiling-with-llvmc">
+<h1><a class="toc-backref" href="#id8">Compiling with <tt class="docutils literal">llvmc</tt></a></h1>
+<p>LLVMC tries hard to be as compatible with <tt class="docutils literal">gcc</tt> as possible,
although there are some small differences. Most of the time, however,
you shouldn't be able to notice them:</p>
<pre class="literal-block">
$ ./a.out
hello
</pre>
-<p>One nice feature of LLVMC is that one doesn't have to distinguish
-between different compilers for different languages (think <tt class="docutils literal"><span class="pre">g++</span></tt> and
-<tt class="docutils literal"><span class="pre">gcc</span></tt>) - the right toolchain is chosen automatically based on input
-language names (which are, in turn, determined from file
-extensions). If you want to force files ending with ".c" to compile as
-C++, use the <tt class="docutils literal"><span class="pre">-x</span></tt> option, just like you would do it with <tt class="docutils literal"><span class="pre">gcc</span></tt>:</p>
+<p>One nice feature of LLVMC is that one doesn't have to distinguish between
+different compilers for different languages (think <tt class="docutils literal">g++</tt> vs. <tt class="docutils literal">gcc</tt>) - the
+right toolchain is chosen automatically based on input language names (which
+are, in turn, determined from file extensions). If you want to force files
+ending with ".c" to compile as C++, use the <tt class="docutils literal"><span class="pre">-x</span></tt> option, just like you would
+do it with <tt class="docutils literal">gcc</tt>:</p>
<pre class="literal-block">
$ # hello.c is really a C++ file
$ llvmc -x c++ hello.c
$ ./a.out
hello
</pre>
-<p>By default, LLVMC uses <tt class="docutils literal"><span class="pre">llvm-gcc</span></tt> to compile the source code. It is
-also possible to choose the work-in-progress <tt class="docutils literal"><span class="pre">clang</span></tt> compiler with
-the <tt class="docutils literal"><span class="pre">-clang</span></tt> option.</p>
+<p>By default, LLVMC uses <tt class="docutils literal"><span class="pre">llvm-gcc</span></tt> to compile the source code. It is also
+possible to choose the <tt class="docutils literal">clang</tt> compiler with the <tt class="docutils literal"><span class="pre">-clang</span></tt> option.</p>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id6" id="predefined-options" name="predefined-options">Predefined options</a></h1>
-<p>LLVMC has some built-in options that can't be overridden in the
-configuration libraries:</p>
+<div class="section" id="predefined-options">
+<h1><a class="toc-backref" href="#id9">Predefined options</a></h1>
+<p>LLVMC has some built-in options that can't be overridden in the TableGen code:</p>
<ul class="simple">
-<li><tt class="docutils literal"><span class="pre">-o</span> <span class="pre">FILE</span></tt> - Output file name.</li>
-<li><tt class="docutils literal"><span class="pre">-x</span> <span class="pre">LANGUAGE</span></tt> - Specify the language of the following input files
+<li><tt class="docutils literal"><span class="pre">-o</span> FILE</tt> - Output file name.</li>
+<li><tt class="docutils literal"><span class="pre">-x</span> LANGUAGE</tt> - Specify the language of the following input files
until the next -x option.</li>
-<li><tt class="docutils literal"><span class="pre">-load</span> <span class="pre">PLUGIN_NAME</span></tt> - Load the specified plugin DLL. Example:
-<tt class="docutils literal"><span class="pre">-load</span> <span class="pre">$LLVM_DIR/Release/lib/LLVMCSimple.so</span></tt>.</li>
<li><tt class="docutils literal"><span class="pre">-v</span></tt> - Enable verbose mode, i.e. print out all executed commands.</li>
+<li><tt class="docutils literal"><span class="pre">--save-temps</span></tt> - Write temporary files to the current directory and do not
+delete them on exit. This option can also take an argument: the
+<tt class="docutils literal"><span class="pre">--save-temps=obj</span></tt> switch will write files into the directory specified with
+the <tt class="docutils literal"><span class="pre">-o</span></tt> option. The <tt class="docutils literal"><span class="pre">--save-temps=cwd</span></tt> and <tt class="docutils literal"><span class="pre">--save-temps</span></tt> switches are
+both synonyms for the default behaviour.</li>
+<li><tt class="docutils literal"><span class="pre">--temp-dir</span> DIRECTORY</tt> - Store temporary files in the given directory. This
+directory is deleted on exit unless <tt class="docutils literal"><span class="pre">--save-temps</span></tt> is specified. If
+<tt class="docutils literal"><span class="pre">--save-temps=obj</span></tt> is also specified, <tt class="docutils literal"><span class="pre">--temp-dir</span></tt> is given the
+precedence.</li>
<li><tt class="docutils literal"><span class="pre">--check-graph</span></tt> - Check the compilation for common errors like mismatched
-output/input language names, multiple default edges and cycles. Because of
-plugins, these checks can't be performed at compile-time. Exit with code zero if
-no errors were found, and return the number of found errors otherwise. Hidden
-option, useful for debugging LLVMC plugins.</li>
+output/input language names, multiple default edges and cycles. Exit with code
+zero if no errors were found, and return the number of found errors
+otherwise. Hidden option, useful for debugging.</li>
<li><tt class="docutils literal"><span class="pre">--view-graph</span></tt> - Show a graphical representation of the compilation graph
-and exit. Requires that you have <tt class="docutils literal"><span class="pre">dot</span></tt> and <tt class="docutils literal"><span class="pre">gv</span></tt> programs installed. Hidden
-option, useful for debugging LLVMC plugins.</li>
+and exit. Requires that you have <tt class="docutils literal">dot</tt> and <tt class="docutils literal">gv</tt> programs installed. Hidden
+option, useful for debugging.</li>
<li><tt class="docutils literal"><span class="pre">--write-graph</span></tt> - Write a <tt class="docutils literal"><span class="pre">compilation-graph.dot</span></tt> file in the current
directory with the compilation graph description in Graphviz format (identical
-to the file used by the <tt class="docutils literal"><span class="pre">--view-graph</span></tt> option). The <tt class="docutils literal"><span class="pre">-o</span></tt> option can be used
-to set the output file name. Hidden option, useful for debugging LLVMC plugins.</li>
-<li><tt class="docutils literal"><span class="pre">--save-temps</span></tt> - Write temporary files to the current directory
-and do not delete them on exit. Hidden option, useful for debugging.</li>
+to the file used by the <tt class="docutils literal"><span class="pre">--view-graph</span></tt> option). The <tt class="docutils literal"><span class="pre">-o</span></tt> option can be
+used to set the output file name. Hidden option, useful for debugging.</li>
<li><tt class="docutils literal"><span class="pre">--help</span></tt>, <tt class="docutils literal"><span class="pre">--help-hidden</span></tt>, <tt class="docutils literal"><span class="pre">--version</span></tt> - These options have
their standard meaning.</li>
</ul>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id7" id="compiling-llvmc-plugins" name="compiling-llvmc-plugins">Compiling LLVMC plugins</a></h1>
-<p>It's easiest to start working on your own LLVMC plugin by copying the
-skeleton project which lives under <tt class="docutils literal"><span class="pre">$LLVMC_DIR/plugins/Simple</span></tt>:</p>
+<div class="section" id="compiling-llvmc-based-drivers">
+<h1><a class="toc-backref" href="#id10">Compiling LLVMC-based drivers</a></h1>
+<p>It's easiest to start working on your own LLVMC driver by copying the skeleton
+project which lives under <tt class="docutils literal">$LLVMC_DIR/examples/Skeleton</tt>:</p>
<pre class="literal-block">
-$ cd $LLVMC_DIR/plugins
-$ cp -r Simple MyPlugin
-$ cd MyPlugin
+$ cd $LLVMC_DIR/examples
+$ cp -r Skeleton MyDriver
+$ cd MyDriver
$ ls
-Makefile PluginMain.cpp Simple.td
-</pre>
-<p>As you can see, our basic plugin consists of only two files (not
-counting the build script). <tt class="docutils literal"><span class="pre">Simple.td</span></tt> contains TableGen
-description of the compilation graph; its format is documented in the
-following sections. <tt class="docutils literal"><span class="pre">PluginMain.cpp</span></tt> is just a helper file used to
-compile the auto-generated C++ code produced from TableGen source. It
-can also contain hook definitions (see <a class="reference" href="#hooks">below</a>).</p>
-<p>The first thing that you should do is to change the <tt class="docutils literal"><span class="pre">LLVMC_PLUGIN</span></tt>
-variable in the <tt class="docutils literal"><span class="pre">Makefile</span></tt> to avoid conflicts (since this variable
-is used to name the resulting library):</p>
-<pre class="literal-block">
-LLVMC_PLUGIN=MyPlugin
+AutoGenerated.td Hooks.cpp Main.cpp Makefile
</pre>
-<p>It is also a good idea to rename <tt class="docutils literal"><span class="pre">Simple.td</span></tt> to something less
-generic:</p>
+<p>As you can see, our basic driver consists of only three files (not counting the
+build script). <tt class="docutils literal">AutoGenerated.td</tt> contains TableGen description of the
+compilation graph; its format is documented in the following
+sections. <tt class="docutils literal">Hooks.cpp</tt> is an empty file that should be used for hook
+definitions (see <a class="reference internal" href="#hooks">below</a>). <tt class="docutils literal">Main.cpp</tt> is just a helper used to compile the
+auto-generated C++ code produced from TableGen source.</p>
+<p>The first thing that you should do is to change the <tt class="docutils literal">LLVMC_BASED_DRIVER</tt>
+variable in the <tt class="docutils literal">Makefile</tt>:</p>
<pre class="literal-block">
-$ mv Simple.td MyPlugin.td
+LLVMC_BASED_DRIVER=MyDriver
</pre>
-<p>Note that the plugin source directory must be placed under
-<tt class="docutils literal"><span class="pre">$LLVMC_DIR/plugins</span></tt> to make use of the existing build
-infrastructure. To build a version of the LLVMC executable called
-<tt class="docutils literal"><span class="pre">mydriver</span></tt> with your plugin compiled in, use the following command:</p>
+<p>It can also be a good idea to put your TableGen code into a file with a less
+generic name:</p>
<pre class="literal-block">
-$ cd $LLVMC_DIR
-$ make BUILTIN_PLUGINS=MyPlugin DRIVER_NAME=mydriver
+$ touch MyDriver.td
+$ vim AutoGenerated.td
+[...]
+include "MyDriver.td"
</pre>
-<p>To build your plugin as a dynamic library, just <tt class="docutils literal"><span class="pre">cd</span></tt> to its source
-directory and run <tt class="docutils literal"><span class="pre">make</span></tt>. The resulting file will be called
-<tt class="docutils literal"><span class="pre">LLVMC$(LLVMC_PLUGIN).$(DLL_EXTENSION)</span></tt> (in our case,
-<tt class="docutils literal"><span class="pre">LLVMCMyPlugin.so</span></tt>). This library can be then loaded in with the
-<tt class="docutils literal"><span class="pre">-load</span></tt> option. Example:</p>
+<p>If you have more than one TableGen source file, they all should be included from
+<tt class="docutils literal">AutoGenerated.td</tt>, since this file is used by the build system to generate
+C++ code.</p>
+<p>To build your driver, just <tt class="docutils literal">cd</tt> to its source directory and run <tt class="docutils literal">make</tt>. The
+resulting executable will be put into <tt class="docutils literal"><span class="pre">$LLVM_OBJ_DIR/$(BuildMode)/bin</span></tt>.</p>
+<p>If you're compiling LLVM with different source and object directories, then you
+must perform the following additional steps before running <tt class="docutils literal">make</tt>:</p>
<pre class="literal-block">
-$ cd $LLVMC_DIR/plugins/Simple
+# LLVMC_SRC_DIR = $LLVM_SRC_DIR/tools/llvmc/
+# LLVMC_OBJ_DIR = $LLVM_OBJ_DIR/tools/llvmc/
+$ mkdir $LLVMC_OBJ_DIR/examples/MyDriver/
+$ cp $LLVMC_SRC_DIR/examples/MyDriver/Makefile \
+ $LLVMC_OBJ_DIR/examples/MyDriver/
+$ cd $LLVMC_OBJ_DIR/examples/MyDriver
$ make
-$ llvmc -load $LLVM_DIR/Release/lib/LLVMCSimple.so
-</pre>
-<p>Sometimes, you will want a 'bare-bones' version of LLVMC that has no
-built-in plugins. It can be compiled with the following command:</p>
-<pre class="literal-block">
-$ cd $LLVMC_DIR
-$ make BUILTIN_PLUGINS=""
</pre>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id8" id="customizing-llvmc-the-compilation-graph" name="customizing-llvmc-the-compilation-graph">Customizing LLVMC: the compilation graph</a></h1>
-<p>Each TableGen configuration file should include the common
-definitions:</p>
+<div class="section" id="customizing-llvmc-the-compilation-graph">
+<h1><a class="toc-backref" href="#id11">Customizing LLVMC: the compilation graph</a></h1>
+<p>Each TableGen configuration file should include the common definitions:</p>
<pre class="literal-block">
include "llvm/CompilerDriver/Common.td"
</pre>
-<p>Internally, LLVMC stores information about possible source
-transformations in form of a graph. Nodes in this graph represent
-tools, and edges between two nodes represent a transformation path. A
-special "root" node is used to mark entry points for the
-transformations. LLVMC also assigns a weight to each edge (more on
-this later) to choose between several alternative edges.</p>
-<p>The definition of the compilation graph (see file
-<tt class="docutils literal"><span class="pre">plugins/Base/Base.td</span></tt> for an example) is just a list of edges:</p>
+<p>Internally, LLVMC stores information about possible source transformations in
+form of a graph. Nodes in this graph represent tools, and edges between two
+nodes represent a transformation path. A special "root" node is used to mark
+entry points for the transformations. LLVMC also assigns a weight to each edge
+(more on this later) to choose between several alternative edges.</p>
+<p>The definition of the compilation graph (see file <tt class="docutils literal">llvmc/src/Base.td</tt> for an
+example) is just a list of edges:</p>
<pre class="literal-block">
def CompilationGraph : CompilationGraph<[
Edge<"root", "llvm_gcc_c">,
]>;
</pre>
-<p>As you can see, the edges can be either default or optional, where
-optional edges are differentiated by an additional <tt class="docutils literal"><span class="pre">case</span></tt> expression
-used to calculate the weight of this edge. Notice also that we refer
-to tools via their names (as strings). This makes it possible to add
-edges to an existing compilation graph in plugins without having to
-know about all tool definitions used in the graph.</p>
-<p>The default edges are assigned a weight of 1, and optional edges get a
-weight of 0 + 2*N where N is the number of tests that evaluated to
-true in the <tt class="docutils literal"><span class="pre">case</span></tt> expression. It is also possible to provide an
-integer parameter to <tt class="docutils literal"><span class="pre">inc_weight</span></tt> and <tt class="docutils literal"><span class="pre">dec_weight</span></tt> - in this case,
-the weight is increased (or decreased) by the provided value instead
-of the default 2. It is also possible to change the default weight of
-an optional edge by using the <tt class="docutils literal"><span class="pre">default</span></tt> clause of the <tt class="docutils literal"><span class="pre">case</span></tt>
+<p>As you can see, the edges can be either default or optional, where optional
+edges are differentiated by an additional <tt class="docutils literal">case</tt> expression used to calculate
+the weight of this edge. Notice also that we refer to tools via their names (as
+strings). This makes it possible to add edges to an existing compilation graph
+without having to know about all tool definitions used in the graph.</p>
+<p>The default edges are assigned a weight of 1, and optional edges get a weight of
+0 + 2*N where N is the number of tests that evaluated to true in the <tt class="docutils literal">case</tt>
+expression. It is also possible to provide an integer parameter to
+<tt class="docutils literal">inc_weight</tt> and <tt class="docutils literal">dec_weight</tt> - in this case, the weight is increased (or
+decreased) by the provided value instead of the default 2. Default weight of an
+optional edge can be changed by using the <tt class="docutils literal">default</tt> clause of the <tt class="docutils literal">case</tt>
construct.</p>
-<p>When passing an input file through the graph, LLVMC picks the edge
-with the maximum weight. To avoid ambiguity, there should be only one
-default edge between two nodes (with the exception of the root node,
-which gets a special treatment - there you are allowed to specify one
-default edge <em>per language</em>).</p>
-<p>When multiple plugins are loaded, their compilation graphs are merged
-together. Since multiple edges that have the same end nodes are not
-allowed (i.e. the graph is not a multigraph), an edge defined in
-several plugins will be replaced by the definition from the plugin
-that was loaded last. Plugin load order can be controlled by using the
-plugin priority feature described above.</p>
-<p>To get a visual representation of the compilation graph (useful for
-debugging), run <tt class="docutils literal"><span class="pre">llvmc</span> <span class="pre">--view-graph</span></tt>. You will need <tt class="docutils literal"><span class="pre">dot</span></tt> and
-<tt class="docutils literal"><span class="pre">gsview</span></tt> installed for this to work properly.</p>
+<p>When passing an input file through the graph, LLVMC picks the edge with the
+maximum weight. To avoid ambiguity, there should be only one default edge
+between two nodes (with the exception of the root node, which gets a special
+treatment - there you are allowed to specify one default edge <em>per language</em>).</p>
+<p>When multiple compilation graphs are defined, they are merged together. Multiple
+edges with the same end nodes are not allowed (i.e. the graph is not a
+multigraph), and will lead to a compile-time error.</p>
+<p>To get a visual representation of the compilation graph (useful for debugging),
+run <tt class="docutils literal">llvmc <span class="pre">--view-graph</span></tt>. You will need <tt class="docutils literal">dot</tt> and <tt class="docutils literal">gsview</tt> installed for
+this to work properly.</p>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id9" id="describing-options" name="describing-options">Describing options</a></h1>
-<p>Command-line options that the plugin supports are defined by using an
-<tt class="docutils literal"><span class="pre">OptionList</span></tt>:</p>
+<div class="section" id="describing-options">
+<h1><a class="toc-backref" href="#id12">Describing options</a></h1>
+<p>Command-line options supported by the driver are defined by using an
+<tt class="docutils literal">OptionList</tt>:</p>
<pre class="literal-block">
def Options : OptionList<[
(switch_option "E", (help "Help string")),
...
]>;
</pre>
-<p>As you can see, the option list is just a list of DAGs, where each DAG
-is an option description consisting of the option name and some
-properties. A plugin can define more than one option list (they are
-all merged together in the end), which can be handy if one wants to
-separate option groups syntactically.</p>
+<p>As you can see, the option list is just a list of DAGs, where each DAG is an
+option description consisting of the option name and some properties. More than
+one option list can be defined (they are all merged together in the end), which
+can be handy if one wants to separate option groups syntactically.</p>
<ul>
<li><p class="first">Possible option types:</p>
<blockquote>
<ul class="simple">
-<li><tt class="docutils literal"><span class="pre">switch_option</span></tt> - a simple boolean switch without arguments, for example
-<tt class="docutils literal"><span class="pre">-O2</span></tt> or <tt class="docutils literal"><span class="pre">-time</span></tt>. At most one occurrence is allowed.</li>
-<li><tt class="docutils literal"><span class="pre">parameter_option</span></tt> - option that takes one argument, for example
+<li><tt class="docutils literal">switch_option</tt> - a simple boolean switch without arguments, for example
+<tt class="docutils literal"><span class="pre">-O2</span></tt> or <tt class="docutils literal"><span class="pre">-time</span></tt>. At most one occurrence is allowed by default.</li>
+<li><tt class="docutils literal">parameter_option</tt> - option that takes one argument, for example
<tt class="docutils literal"><span class="pre">-std=c99</span></tt>. It is also allowed to use spaces instead of the equality
-sign: <tt class="docutils literal"><span class="pre">-std</span> <span class="pre">c99</span></tt>. At most one occurrence is allowed.</li>
-<li><tt class="docutils literal"><span class="pre">parameter_list_option</span></tt> - same as the above, but more than one option
-occurence is allowed.</li>
-<li><tt class="docutils literal"><span class="pre">prefix_option</span></tt> - same as the parameter_option, but the option name and
+sign: <tt class="docutils literal"><span class="pre">-std</span> c99</tt>. At most one occurrence is allowed.</li>
+<li><tt class="docutils literal">parameter_list_option</tt> - same as the above, but more than one option
+occurrence is allowed.</li>
+<li><tt class="docutils literal">prefix_option</tt> - same as the parameter_option, but the option name and
argument do not have to be separated. Example: <tt class="docutils literal"><span class="pre">-ofile</span></tt>. This can be also
-specified as <tt class="docutils literal"><span class="pre">-o</span> <span class="pre">file</span></tt>; however, <tt class="docutils literal"><span class="pre">-o=file</span></tt> will be parsed incorrectly
-(<tt class="docutils literal"><span class="pre">=file</span></tt> will be interpreted as option value). At most one occurrence is
+specified as <tt class="docutils literal"><span class="pre">-o</span> file</tt>; however, <tt class="docutils literal"><span class="pre">-o=file</span></tt> will be parsed incorrectly
+(<tt class="docutils literal">=file</tt> will be interpreted as option value). At most one occurrence is
allowed.</li>
-<li><tt class="docutils literal"><span class="pre">prefix_list_option</span></tt> - same as the above, but more than one occurence of
+<li><tt class="docutils literal">prefix_list_option</tt> - same as the above, but more than one occurrence of
the option is allowed; example: <tt class="docutils literal"><span class="pre">-lm</span> <span class="pre">-lpthread</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">alias_option</span></tt> - a special option type for creating aliases. Unlike other
+<li><tt class="docutils literal">alias_option</tt> - a special option type for creating aliases. Unlike other
option types, aliases are not allowed to have any properties besides the
-aliased option name. Usage example: <tt class="docutils literal"><span class="pre">(alias_option</span> <span class="pre">"preprocess",</span> <span class="pre">"E")</span></tt></li>
+aliased option name.
+Usage example: <tt class="docutils literal">(alias_option "preprocess", "E")</tt></li>
+<li><tt class="docutils literal">switch_list_option</tt> - like <tt class="docutils literal">switch_option</tt> with the <tt class="docutils literal">zero_or_more</tt>
+property, but remembers how many times the switch was turned on. Useful
+mostly for forwarding. Example: when <tt class="docutils literal"><span class="pre">-foo</span></tt> is a switch option (with the
+<tt class="docutils literal">zero_or_more</tt> property), the command <tt class="docutils literal">driver <span class="pre">-foo</span> <span class="pre">-foo</span></tt> is forwarded
+as <tt class="docutils literal"><span class="pre">some-tool</span> <span class="pre">-foo</span></tt>, but when <tt class="docutils literal"><span class="pre">-foo</span></tt> is a switch list, the same command
+is forwarded as <tt class="docutils literal"><span class="pre">some-tool</span> <span class="pre">-foo</span> <span class="pre">-foo</span></tt>.</li>
</ul>
</blockquote>
</li>
<li><p class="first">Possible option properties:</p>
<blockquote>
<ul class="simple">
-<li><tt class="docutils literal"><span class="pre">help</span></tt> - help string associated with this option. Used for <tt class="docutils literal"><span class="pre">--help</span></tt>
+<li><tt class="docutils literal">help</tt> - help string associated with this option. Used for <tt class="docutils literal"><span class="pre">--help</span></tt>
output.</li>
-<li><tt class="docutils literal"><span class="pre">required</span></tt> - this option must be specified exactly once (or, in case of
-the list options without the <tt class="docutils literal"><span class="pre">multi_val</span></tt> property, at least
-once). Incompatible with <tt class="docutils literal"><span class="pre">zero_or_one</span></tt> and <tt class="docutils literal"><span class="pre">one_or_more</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">one_or_more</span></tt> - the option must be specified at least one time. Useful
-only for list options in conjunction with <tt class="docutils literal"><span class="pre">multi_val</span></tt>; for ordinary lists
-it is synonymous with <tt class="docutils literal"><span class="pre">required</span></tt>. Incompatible with <tt class="docutils literal"><span class="pre">required</span></tt> and
-<tt class="docutils literal"><span class="pre">zero_or_one</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">zero_or_one</span></tt> - the option can be specified zero or one times. Useful
-only for list options in conjunction with <tt class="docutils literal"><span class="pre">multi_val</span></tt>. Incompatible with
-<tt class="docutils literal"><span class="pre">required</span></tt> and <tt class="docutils literal"><span class="pre">one_or_more</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">hidden</span></tt> - the description of this option will not appear in
+<li><tt class="docutils literal">required</tt> - this option must be specified exactly once (or, in case of
+the list options without the <tt class="docutils literal">multi_val</tt> property, at least
+once). Incompatible with <tt class="docutils literal">optional</tt> and <tt class="docutils literal">one_or_more</tt>.</li>
+<li><tt class="docutils literal">optional</tt> - the option can be specified either zero times or exactly
+once. The default for switch options. Useful only for list options in
+conjunction with <tt class="docutils literal">multi_val</tt>. Incompatible with <tt class="docutils literal">required</tt>,
+<tt class="docutils literal">zero_or_more</tt> and <tt class="docutils literal">one_or_more</tt>.</li>
+<li><tt class="docutils literal">one_or_more</tt> - the option must be specified at least once. Can be useful
+to allow switch options be both obligatory and be specified multiple
+times. For list options is useful only in conjunction with <tt class="docutils literal">multi_val</tt>;
+for ordinary it is synonymous with <tt class="docutils literal">required</tt>. Incompatible with
+<tt class="docutils literal">required</tt>, <tt class="docutils literal">optional</tt> and <tt class="docutils literal">zero_or_more</tt>.</li>
+<li><tt class="docutils literal">zero_or_more</tt> - the option can be specified zero or more times. Useful
+to allow a single switch option to be specified more than
+once. Incompatible with <tt class="docutils literal">required</tt>, <tt class="docutils literal">optional</tt> and <tt class="docutils literal">one_or_more</tt>.</li>
+<li><tt class="docutils literal">hidden</tt> - the description of this option will not appear in
the <tt class="docutils literal"><span class="pre">--help</span></tt> output (but will appear in the <tt class="docutils literal"><span class="pre">--help-hidden</span></tt>
output).</li>
-<li><tt class="docutils literal"><span class="pre">really_hidden</span></tt> - the option will not be mentioned in any help
+<li><tt class="docutils literal">really_hidden</tt> - the option will not be mentioned in any help
output.</li>
-<li><tt class="docutils literal"><span class="pre">multi_val</span> <span class="pre">n</span></tt> - this option takes <em>n</em> arguments (can be useful in some
-special cases). Usage example: <tt class="docutils literal"><span class="pre">(parameter_list_option</span> <span class="pre">"foo",</span> <span class="pre">(multi_val</span>
-<span class="pre">3))</span></tt>. Only list options can have this attribute; you can, however, use
-the <tt class="docutils literal"><span class="pre">one_or_more</span></tt> and <tt class="docutils literal"><span class="pre">zero_or_one</span></tt> properties.</li>
-<li><tt class="docutils literal"><span class="pre">extern</span></tt> - this option is defined in some other plugin, see below.</li>
+<li><tt class="docutils literal">comma_separated</tt> - Indicates that any commas specified for an option's
+value should be used to split the value up into multiple values for the
+option. This property is valid only for list options. In conjunction with
+<tt class="docutils literal">forward_value</tt> can be used to implement option forwarding in style of
+gcc's <tt class="docutils literal"><span class="pre">-Wa,</span></tt>.</li>
+<li><tt class="docutils literal">multi_val n</tt> - this option takes <em>n</em> arguments (can be useful in some
+special cases). Usage example: <tt class="docutils literal">(parameter_list_option "foo", (multi_val
+3))</tt>; the command-line syntax is '-foo a b c'. Only list options can have
+this attribute; you can, however, use the <tt class="docutils literal">one_or_more</tt>, <tt class="docutils literal">optional</tt>
+and <tt class="docutils literal">required</tt> properties.</li>
+<li><tt class="docutils literal">init</tt> - this option has a default value, either a string (if it is a
+parameter), or a boolean (if it is a switch; as in C++, boolean constants
+are called <tt class="docutils literal">true</tt> and <tt class="docutils literal">false</tt>). List options can't have <tt class="docutils literal">init</tt>
+attribute.
+Usage examples: <tt class="docutils literal">(switch_option "foo", (init true))</tt>; <tt class="docutils literal">(prefix_option
+"bar", (init <span class="pre">"baz"))</span></tt>.</li>
</ul>
</blockquote>
</li>
</ul>
-<div class="section">
-<h2><a class="toc-backref" href="#id10" id="external-options" name="external-options">External options</a></h2>
-<p>Sometimes, when linking several plugins together, one plugin needs to
-access options defined in some other plugin. Because of the way
-options are implemented, such options must be marked as
-<tt class="docutils literal"><span class="pre">extern</span></tt>. This is what the <tt class="docutils literal"><span class="pre">extern</span></tt> option property is
-for. Example:</p>
-<pre class="literal-block">
-...
-(switch_option "E", (extern))
-...
-</pre>
-<p>See also the section on plugin <a class="reference" href="#priorities">priorities</a>.</p>
-</div>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id11" id="conditional-evaluation" name="conditional-evaluation"><span id="case"></span>Conditional evaluation</a></h1>
-<p>The 'case' construct is the main means by which programmability is
-achieved in LLVMC. It can be used to calculate edge weights, program
-actions and modify the shell commands to be executed. The 'case'
-expression is designed after the similarly-named construct in
-functional languages and takes the form <tt class="docutils literal"><span class="pre">(case</span> <span class="pre">(test_1),</span> <span class="pre">statement_1,</span>
-<span class="pre">(test_2),</span> <span class="pre">statement_2,</span> <span class="pre">...</span> <span class="pre">(test_N),</span> <span class="pre">statement_N)</span></tt>. The statements
-are evaluated only if the corresponding tests evaluate to true.</p>
+<div class="section" id="conditional-evaluation">
+<span id="case"></span><h1><a class="toc-backref" href="#id13">Conditional evaluation</a></h1>
+<p>The 'case' construct is the main means by which programmability is achieved in
+LLVMC. It can be used to calculate edge weights, program actions and modify the
+shell commands to be executed. The 'case' expression is designed after the
+similarly-named construct in functional languages and takes the form <tt class="docutils literal">(case
+(test_1), statement_1, (test_2), statement_2, ... (test_N), statement_N)</tt>. The
+statements are evaluated only if the corresponding tests evaluate to true.</p>
<p>Examples:</p>
<pre class="literal-block">
// Edge weight calculation
(switch_on "B"), "cmdline2",
(default), "cmdline3")
</pre>
-<p>Note the slight difference in 'case' expression handling in contexts
-of edge weights and command line specification - in the second example
-the value of the <tt class="docutils literal"><span class="pre">"B"</span></tt> switch is never checked when switch <tt class="docutils literal"><span class="pre">"A"</span></tt> is
-enabled, and the whole expression always evaluates to <tt class="docutils literal"><span class="pre">"cmdline1"</span></tt> in
-that case.</p>
+<p>Note the slight difference in 'case' expression handling in contexts of edge
+weights and command line specification - in the second example the value of the
+<tt class="docutils literal">"B"</tt> switch is never checked when switch <tt class="docutils literal">"A"</tt> is enabled, and the whole
+expression always evaluates to <tt class="docutils literal">"cmdline1"</tt> in that case.</p>
<p>Case expressions can also be nested, i.e. the following is legal:</p>
<pre class="literal-block">
(case (switch_on "E"), (case (switch_on "o"), ..., (default), ...)
(default), ...)
</pre>
-<p>You should, however, try to avoid doing that because it hurts
-readability. It is usually better to split tool descriptions and/or
-use TableGen inheritance instead.</p>
+<p>You should, however, try to avoid doing that because it hurts readability. It is
+usually better to split tool descriptions and/or use TableGen inheritance
+instead.</p>
<ul class="simple">
<li>Possible tests are:<ul>
-<li><tt class="docutils literal"><span class="pre">switch_on</span></tt> - Returns true if a given command-line switch is
-provided by the user. Example: <tt class="docutils literal"><span class="pre">(switch_on</span> <span class="pre">"opt")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">parameter_equals</span></tt> - Returns true if a command-line parameter equals
-a given value.
-Example: <tt class="docutils literal"><span class="pre">(parameter_equals</span> <span class="pre">"W",</span> <span class="pre">"all")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">element_in_list</span></tt> - Returns true if a command-line parameter
-list contains a given value.
-Example: <tt class="docutils literal"><span class="pre">(parameter_in_list</span> <span class="pre">"l",</span> <span class="pre">"pthread")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">input_languages_contain</span></tt> - Returns true if a given language
+<li><tt class="docutils literal">switch_on</tt> - Returns true if a given command-line switch is provided by
+the user. Can be given multiple arguments, in that case <tt class="docutils literal">(switch_on "foo",
+"bar", "baz")</tt> is equivalent to <tt class="docutils literal">(and (switch_on <span class="pre">"foo"),</span> (switch_on
+<span class="pre">"bar"),</span> (switch_on <span class="pre">"baz"))</span></tt>.
+Example: <tt class="docutils literal">(switch_on "opt")</tt>.</li>
+<li><tt class="docutils literal">any_switch_on</tt> - Given a number of switch options, returns true if any of
+the switches is turned on.
+Example: <tt class="docutils literal">(any_switch_on "foo", "bar", "baz")</tt> is equivalent to <tt class="docutils literal">(or
+(switch_on <span class="pre">"foo"),</span> (switch_on <span class="pre">"bar"),</span> (switch_on <span class="pre">"baz"))</span></tt>.</li>
+<li><tt class="docutils literal">parameter_equals</tt> - Returns true if a command-line parameter (first
+argument) equals a given value (second argument).
+Example: <tt class="docutils literal">(parameter_equals "W", "all")</tt>.</li>
+<li><tt class="docutils literal">element_in_list</tt> - Returns true if a command-line parameter list (first
+argument) contains a given value (second argument).
+Example: <tt class="docutils literal">(element_in_list "l", "pthread")</tt>.</li>
+<li><tt class="docutils literal">input_languages_contain</tt> - Returns true if a given language
belongs to the current input language set.
-Example: <tt class="docutils literal"><span class="pre">(input_languages_contain</span> <span class="pre">"c++")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">in_language</span></tt> - Evaluates to true if the input file language
-equals to the argument. At the moment works only with <tt class="docutils literal"><span class="pre">cmd_line</span></tt>
-and <tt class="docutils literal"><span class="pre">actions</span></tt> (on non-join nodes).
-Example: <tt class="docutils literal"><span class="pre">(in_language</span> <span class="pre">"c++")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">not_empty</span></tt> - Returns true if a given option (which should be
-either a parameter or a parameter list) is set by the
-user.
-Example: <tt class="docutils literal"><span class="pre">(not_empty</span> <span class="pre">"o")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">empty</span></tt> - The opposite of <tt class="docutils literal"><span class="pre">not_empty</span></tt>. Equivalent to <tt class="docutils literal"><span class="pre">(not</span> <span class="pre">(not_empty</span>
-<span class="pre">X))</span></tt>. Provided for convenience.</li>
-<li><tt class="docutils literal"><span class="pre">default</span></tt> - Always evaluates to true. Should always be the last
-test in the <tt class="docutils literal"><span class="pre">case</span></tt> expression.</li>
-<li><tt class="docutils literal"><span class="pre">and</span></tt> - A standard logical combinator that returns true iff all
-of its arguments return true. Used like this: <tt class="docutils literal"><span class="pre">(and</span> <span class="pre">(test1),</span>
-<span class="pre">(test2),</span> <span class="pre">...</span> <span class="pre">(testN))</span></tt>. Nesting of <tt class="docutils literal"><span class="pre">and</span></tt> and <tt class="docutils literal"><span class="pre">or</span></tt> is allowed,
-but not encouraged.</li>
-<li><tt class="docutils literal"><span class="pre">or</span></tt> - Another logical combinator that returns true only if any
-one of its arguments returns true. Example: <tt class="docutils literal"><span class="pre">(or</span> <span class="pre">(test1),</span>
-<span class="pre">(test2),</span> <span class="pre">...</span> <span class="pre">(testN))</span></tt>.</li>
+Example: <tt class="docutils literal">(input_languages_contain <span class="pre">"c++")</span></tt>.</li>
+<li><tt class="docutils literal">in_language</tt> - Evaluates to true if the input file language is equal to
+the argument. At the moment works only with <tt class="docutils literal">command</tt> and <tt class="docutils literal">actions</tt> (on
+non-join nodes).
+Example: <tt class="docutils literal">(in_language <span class="pre">"c++")</span></tt>.</li>
+<li><tt class="docutils literal">not_empty</tt> - Returns true if a given option (which should be either a
+parameter or a parameter list) is set by the user. Like <tt class="docutils literal">switch_on</tt>, can
+be also given multiple arguments.
+Examples: <tt class="docutils literal">(not_empty "o")</tt>, <tt class="docutils literal">(not_empty "o", "l")</tt>.</li>
+<li><tt class="docutils literal">any_not_empty</tt> - Returns true if <tt class="docutils literal">not_empty</tt> returns true for any of
+the provided options.
+Example: <tt class="docutils literal">(any_not_empty "foo", "bar", "baz")</tt> is equivalent to <tt class="docutils literal">(or
+(not_empty <span class="pre">"foo"),</span> (not_empty <span class="pre">"bar"),</span> (not_empty <span class="pre">"baz"))</span></tt>.</li>
+<li><tt class="docutils literal">empty</tt> - The opposite of <tt class="docutils literal">not_empty</tt>. Equivalent to <tt class="docutils literal">(not (not_empty
+X))</tt>. Can be given multiple arguments.</li>
+<li><tt class="docutils literal">any_not_empty</tt> - Returns true if <tt class="docutils literal">not_empty</tt> returns true for any of
+the provided options.
+Example: <tt class="docutils literal">(any_empty "foo", "bar", "baz")</tt> is equivalent to <tt class="docutils literal">(or
+(not_empty <span class="pre">"foo"),</span> (not_empty <span class="pre">"bar"),</span> (not_empty <span class="pre">"baz"))</span></tt>.</li>
+<li><tt class="docutils literal">single_input_file</tt> - Returns true if there was only one input file
+provided on the command-line. Used without arguments:
+<tt class="docutils literal">(single_input_file)</tt>.</li>
+<li><tt class="docutils literal">multiple_input_files</tt> - Equivalent to <tt class="docutils literal">(not (single_input_file))</tt> (the
+case of zero input files is considered an error).</li>
+<li><tt class="docutils literal">default</tt> - Always evaluates to true. Should always be the last
+test in the <tt class="docutils literal">case</tt> expression.</li>
+<li><tt class="docutils literal">and</tt> - A standard logical combinator that returns true iff all of
+its arguments return true. Used like this: <tt class="docutils literal">(and (test1), (test2),
+... (testN))</tt>. Nesting of <tt class="docutils literal">and</tt> and <tt class="docutils literal">or</tt> is allowed, but not
+encouraged.</li>
+<li><tt class="docutils literal">or</tt> - A logical combinator that returns true iff any of its arguments
+return true.
+Example: <tt class="docutils literal">(or (test1), (test2), ... (testN))</tt>.</li>
+<li><tt class="docutils literal">not</tt> - Standard unary logical combinator that negates its
+argument.
+Example: <tt class="docutils literal">(not (or (test1), (test2), ... <span class="pre">(testN)))</span></tt>.</li>
</ul>
</li>
</ul>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id12" id="writing-a-tool-description" name="writing-a-tool-description">Writing a tool description</a></h1>
-<p>As was said earlier, nodes in the compilation graph represent tools,
-which are described separately. A tool definition looks like this
-(taken from the <tt class="docutils literal"><span class="pre">include/llvm/CompilerDriver/Tools.td</span></tt> file):</p>
+<div class="section" id="writing-a-tool-description">
+<h1><a class="toc-backref" href="#id14">Writing a tool description</a></h1>
+<p>As was said earlier, nodes in the compilation graph represent tools, which are
+described separately. A tool definition looks like this (taken from the
+<tt class="docutils literal">llvmc/src/Base.td</tt> file):</p>
<pre class="literal-block">
def llvm_gcc_cpp : Tool<[
(in_language "c++"),
(out_language "llvm-assembler"),
(output_suffix "bc"),
- (cmd_line "llvm-g++ -c $INFILE -o $OUTFILE -emit-llvm"),
+ (command "llvm-g++ -c -emit-llvm"),
(sink)
]>;
</pre>
-<p>This defines a new tool called <tt class="docutils literal"><span class="pre">llvm_gcc_cpp</span></tt>, which is an alias for
-<tt class="docutils literal"><span class="pre">llvm-g++</span></tt>. As you can see, a tool definition is just a list of
-properties; most of them should be self-explanatory. The <tt class="docutils literal"><span class="pre">sink</span></tt>
-property means that this tool should be passed all command-line
-options that aren't mentioned in the option list.</p>
+<p>This defines a new tool called <tt class="docutils literal">llvm_gcc_cpp</tt>, which is an alias for
+<tt class="docutils literal"><span class="pre">llvm-g++</span></tt>. As you can see, a tool definition is just a list of properties;
+most of them should be self-explanatory. The <tt class="docutils literal">sink</tt> property means that this
+tool should be passed all command-line options that aren't mentioned in the
+option list.</p>
<p>The complete list of all currently implemented tool properties follows.</p>
<ul class="simple">
<li>Possible tool properties:<ul>
-<li><tt class="docutils literal"><span class="pre">in_language</span></tt> - input language name. Can be either a string or a
-list, in case the tool supports multiple input languages.</li>
-<li><tt class="docutils literal"><span class="pre">out_language</span></tt> - output language name. Tools are not allowed to
-have multiple output languages.</li>
-<li><tt class="docutils literal"><span class="pre">output_suffix</span></tt> - output file suffix. Can also be changed
-dynamically, see documentation on actions.</li>
-<li><tt class="docutils literal"><span class="pre">cmd_line</span></tt> - the actual command used to run the tool. You can
-use <tt class="docutils literal"><span class="pre">$INFILE</span></tt> and <tt class="docutils literal"><span class="pre">$OUTFILE</span></tt> variables, output redirection
-with <tt class="docutils literal"><span class="pre">></span></tt>, hook invocations (<tt class="docutils literal"><span class="pre">$CALL</span></tt>), environment variables
-(via <tt class="docutils literal"><span class="pre">$ENV</span></tt>) and the <tt class="docutils literal"><span class="pre">case</span></tt> construct.</li>
-<li><tt class="docutils literal"><span class="pre">join</span></tt> - this tool is a "join node" in the graph, i.e. it gets a
-list of input files and joins them together. Used for linkers.</li>
-<li><tt class="docutils literal"><span class="pre">sink</span></tt> - all command-line options that are not handled by other
-tools are passed to this tool.</li>
-<li><tt class="docutils literal"><span class="pre">actions</span></tt> - A single big <tt class="docutils literal"><span class="pre">case</span></tt> expression that specifies how
-this tool reacts on command-line options (described in more detail
-below).</li>
+<li><tt class="docutils literal">in_language</tt> - input language name. Can be given multiple arguments, in
+case the tool supports multiple input languages. Used for typechecking and
+mapping file extensions to tools.</li>
+<li><tt class="docutils literal">out_language</tt> - output language name. Multiple output languages are
+allowed. Used for typechecking the compilation graph.</li>
+<li><tt class="docutils literal">output_suffix</tt> - output file suffix. Can also be changed dynamically, see
+documentation on <a class="reference internal" href="#actions">actions</a>.</li>
</ul>
</li>
</ul>
-<div class="section">
-<h2><a class="toc-backref" href="#id13" id="actions" name="actions">Actions</a></h2>
-<p>A tool often needs to react to command-line options, and this is
-precisely what the <tt class="docutils literal"><span class="pre">actions</span></tt> property is for. The next example
-illustrates this feature:</p>
+<blockquote>
+<ul class="simple">
+<li><tt class="docutils literal">command</tt> - the actual command used to run the tool. You can use output
+redirection with <tt class="docutils literal">></tt>, hook invocations (<tt class="docutils literal">$CALL</tt>), environment variables
+(via <tt class="docutils literal">$ENV</tt>) and the <tt class="docutils literal">case</tt> construct.</li>
+<li><tt class="docutils literal">join</tt> - this tool is a "join node" in the graph, i.e. it gets a list of
+input files and joins them together. Used for linkers.</li>
+<li><tt class="docutils literal">sink</tt> - all command-line options that are not handled by other tools are
+passed to this tool.</li>
+<li><tt class="docutils literal">actions</tt> - A single big <tt class="docutils literal">case</tt> expression that specifies how this tool
+reacts on command-line options (described in more detail <a class="reference internal" href="#actions">below</a>).</li>
+</ul>
+</blockquote>
+<blockquote>
+<ul class="simple">
+<li><tt class="docutils literal">out_file_option</tt>, <tt class="docutils literal">in_file_option</tt> - Options appended to the
+<tt class="docutils literal">command</tt> string to designate output and input files. Default values are
+<tt class="docutils literal"><span class="pre">"-o"</span></tt> and <tt class="docutils literal">""</tt>, respectively.</li>
+</ul>
+</blockquote>
+<div class="section" id="id4">
+<span id="actions"></span><h2><a class="toc-backref" href="#id15">Actions</a></h2>
+<p>A tool often needs to react to command-line options, and this is precisely what
+the <tt class="docutils literal">actions</tt> property is for. The next example illustrates this feature:</p>
<pre class="literal-block">
def llvm_gcc_linker : Tool<[
(in_language "object-code"),
(out_language "executable"),
(output_suffix "out"),
- (cmd_line "llvm-gcc $INFILE -o $OUTFILE"),
+ (command "llvm-gcc"),
(join),
(actions (case (not_empty "L"), (forward "L"),
(not_empty "l"), (forward "l"),
[(append_cmd "-dummy1"), (append_cmd "-dummy2")])
]>;
</pre>
-<p>The <tt class="docutils literal"><span class="pre">actions</span></tt> tool property is implemented on top of the omnipresent
-<tt class="docutils literal"><span class="pre">case</span></tt> expression. It associates one or more different <em>actions</em>
-with given conditions - in the example, the actions are <tt class="docutils literal"><span class="pre">forward</span></tt>,
-which forwards a given option unchanged, and <tt class="docutils literal"><span class="pre">append_cmd</span></tt>, which
-appends a given string to the tool execution command. Multiple actions
-can be associated with a single condition by using a list of actions
-(used in the example to append some dummy options). The same <tt class="docutils literal"><span class="pre">case</span></tt>
-construct can also be used in the <tt class="docutils literal"><span class="pre">cmd_line</span></tt> property to modify the
-tool command line.</p>
-<p>The "join" property used in the example means that this tool behaves
-like a linker.</p>
+<p>The <tt class="docutils literal">actions</tt> tool property is implemented on top of the omnipresent <tt class="docutils literal">case</tt>
+expression. It associates one or more different <em>actions</em> with given
+conditions - in the example, the actions are <tt class="docutils literal">forward</tt>, which forwards a given
+option unchanged, and <tt class="docutils literal">append_cmd</tt>, which appends a given string to the tool
+execution command. Multiple actions can be associated with a single condition by
+using a list of actions (used in the example to append some dummy options). The
+same <tt class="docutils literal">case</tt> construct can also be used in the <tt class="docutils literal">cmd_line</tt> property to modify
+the tool command line.</p>
+<p>The "join" property used in the example means that this tool behaves like a
+linker.</p>
<p>The list of all possible actions follows.</p>
<ul>
<li><p class="first">Possible actions:</p>
<blockquote>
<ul class="simple">
-<li><tt class="docutils literal"><span class="pre">append_cmd</span></tt> - append a string to the tool invocation
-command.
-Example: <tt class="docutils literal"><span class="pre">(case</span> <span class="pre">(switch_on</span> <span class="pre">"pthread"),</span> <span class="pre">(append_cmd</span>
-<span class="pre">"-lpthread"))</span></tt></li>
-<li><tt class="docutils literal"><span class="pre">error`</span> <span class="pre">-</span> <span class="pre">exit</span> <span class="pre">with</span> <span class="pre">error.</span>
-<span class="pre">Example:</span> <span class="pre">``(error</span> <span class="pre">"Mixing</span> <span class="pre">-c</span> <span class="pre">and</span> <span class="pre">-S</span> <span class="pre">is</span> <span class="pre">not</span> <span class="pre">allowed!")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">forward</span></tt> - forward an option unchanged.
-Example: <tt class="docutils literal"><span class="pre">(forward</span> <span class="pre">"Wall")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">forward_as</span></tt> - Change the name of an option, but forward the
-argument unchanged.
-Example: <tt class="docutils literal"><span class="pre">(forward_as</span> <span class="pre">"O0"</span> <span class="pre">"--disable-optimization")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">output_suffix</span></tt> - modify the output suffix of this
-tool.
-Example: <tt class="docutils literal"><span class="pre">(output_suffix</span> <span class="pre">"i")</span></tt>.</li>
-<li><tt class="docutils literal"><span class="pre">stop_compilation</span></tt> - stop compilation after this tool processes
-its input. Used without arguments.</li>
-<li><tt class="docutils literal"><span class="pre">unpack_values</span></tt> - used for for splitting and forwarding
-comma-separated lists of options, e.g. <tt class="docutils literal"><span class="pre">-Wa,-foo=bar,-baz</span></tt> is
-converted to <tt class="docutils literal"><span class="pre">-foo=bar</span> <span class="pre">-baz</span></tt> and appended to the tool invocation
-command.
-Example: <tt class="docutils literal"><span class="pre">(unpack_values</span> <span class="pre">"Wa,")</span></tt>.</li>
+<li><tt class="docutils literal">append_cmd</tt> - Append a string to the tool invocation command.
+Example: <tt class="docutils literal">(case (switch_on <span class="pre">"pthread"),</span> (append_cmd <span class="pre">"-lpthread"))</span></tt>.</li>
+<li><tt class="docutils literal">error</tt> - Exit with error.
+Example: <tt class="docutils literal">(error "Mixing <span class="pre">-c</span> and <span class="pre">-S</span> is not <span class="pre">allowed!")</span></tt>.</li>
+<li><tt class="docutils literal">warning</tt> - Print a warning.
+Example: <tt class="docutils literal">(warning "Specifying both <span class="pre">-O1</span> and <span class="pre">-O2</span> is <span class="pre">meaningless!")</span></tt>.</li>
+<li><tt class="docutils literal">forward</tt> - Forward the option unchanged.
+Example: <tt class="docutils literal">(forward "Wall")</tt>.</li>
+<li><tt class="docutils literal">forward_as</tt> - Change the option's name, but forward the argument
+unchanged.
+Example: <tt class="docutils literal">(forward_as "O0", <span class="pre">"--disable-optimization")</span></tt>.</li>
+<li><tt class="docutils literal">forward_value</tt> - Forward only option's value. Cannot be used with switch
+options (since they don't have values), but works fine with lists.
+Example: <tt class="docutils literal">(forward_value <span class="pre">"Wa,")</span></tt>.</li>
+<li><tt class="docutils literal">forward_transformed_value</tt> - As above, but applies a hook to the
+option's value before forwarding (see <a class="reference internal" href="#hooks">below</a>). When
+<tt class="docutils literal">forward_transformed_value</tt> is applied to a list
+option, the hook must have signature
+<tt class="docutils literal"><span class="pre">std::string</span> <span class="pre">hooks::HookName</span> (const <span class="pre">std::vector<std::string>&)</span></tt>.
+Example: <tt class="docutils literal">(forward_transformed_value "m", "ConvertToMAttr")</tt>.</li>
+<li><tt class="docutils literal">output_suffix</tt> - Modify the output suffix of this tool.
+Example: <tt class="docutils literal">(output_suffix "i")</tt>.</li>
+<li><tt class="docutils literal">stop_compilation</tt> - Stop compilation after this tool processes its
+input. Used without arguments.
+Example: <tt class="docutils literal">(stop_compilation)</tt>.</li>
</ul>
</blockquote>
</li>
</ul>
</div>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id14" id="language-map" name="language-map">Language map</a></h1>
-<p>If you are adding support for a new language to LLVMC, you'll need to
-modify the language map, which defines mappings from file extensions
-to language names. It is used to choose the proper toolchain(s) for a
-given input file set. Language map definition looks like this:</p>
+<div class="section" id="language-map">
+<h1><a class="toc-backref" href="#id16">Language map</a></h1>
+<p>If you are adding support for a new language to LLVMC, you'll need to modify the
+language map, which defines mappings from file extensions to language names. It
+is used to choose the proper toolchain(s) for a given input file set. Language
+map definition looks like this:</p>
<pre class="literal-block">
def LanguageMap : LanguageMap<
[LangToSuffixes<"c++", ["cc", "cp", "cxx", "cpp", "CPP", "c++", "C"]>,
$ llvmc hello.cpp
llvmc: Unknown suffix: cpp
</pre>
-<p>The language map entries should be added only for tools that are
-linked with the root node. Since tools are not allowed to have
-multiple output languages, for nodes "inside" the graph the input and
-output languages should match. This is enforced at compile-time.</p>
+<p>The language map entries are needed only for the tools that are linked from the
+root node. A tool can have multiple output languages.</p>
+</div>
+<div class="section" id="option-preprocessor">
+<h1><a class="toc-backref" href="#id17">Option preprocessor</a></h1>
+<p>It is sometimes useful to run error-checking code before processing the
+compilation graph. For example, if optimization options "-O1" and "-O2" are
+implemented as switches, we might want to output a warning if the user invokes
+the driver with both of these options enabled.</p>
+<p>The <tt class="docutils literal">OptionPreprocessor</tt> feature is reserved specially for these
+occasions. Example (adapted from <tt class="docutils literal">llvm/src/Base.td.in</tt>):</p>
+<pre class="literal-block">
+def Preprocess : OptionPreprocessor<
+(case (not (any_switch_on "O0", "O1", "O2", "O3")),
+ (set_option "O2"),
+ (and (switch_on "O3"), (any_switch_on "O0", "O1", "O2")),
+ (unset_option "O0", "O1", "O2"),
+ (and (switch_on "O2"), (any_switch_on "O0", "O1")),
+ (unset_option "O0", "O1"),
+ (and (switch_on "O1"), (switch_on "O0")),
+ (unset_option "O0"))
+>;
+</pre>
+<p>Here, <tt class="docutils literal">OptionPreprocessor</tt> is used to unset all spurious <tt class="docutils literal"><span class="pre">-O</span></tt> options so
+that they are not forwarded to the compiler. If no optimization options are
+specified, <tt class="docutils literal"><span class="pre">-O2</span></tt> is enabled.</p>
+<p><tt class="docutils literal">OptionPreprocessor</tt> is basically a single big <tt class="docutils literal">case</tt> expression, which is
+evaluated only once right after the driver is started. The only allowed actions
+in <tt class="docutils literal">OptionPreprocessor</tt> are <tt class="docutils literal">error</tt>, <tt class="docutils literal">warning</tt>, and two special actions:
+<tt class="docutils literal">unset_option</tt> and <tt class="docutils literal">set_option</tt>. As their names suggest, they can be used to
+set or unset a given option. To set an option with <tt class="docutils literal">set_option</tt>, use the
+two-argument form: <tt class="docutils literal">(set_option "parameter", VALUE)</tt>. Here, <tt class="docutils literal">VALUE</tt> can be
+either a string, a string list, or a boolean constant.</p>
+<p>For convenience, <tt class="docutils literal">set_option</tt> and <tt class="docutils literal">unset_option</tt> also work with multiple
+arguments. That is, instead of <tt class="docutils literal">[(unset_option <span class="pre">"A"),</span> (unset_option <span class="pre">"B")]</span></tt> you
+can use <tt class="docutils literal">(unset_option "A", "B")</tt>. Obviously, <tt class="docutils literal">(set_option "A", "B")</tt> is
+only valid if both <tt class="docutils literal">A</tt> and <tt class="docutils literal">B</tt> are switches.</p>
</div>
-<div class="section">
-<h1><a class="toc-backref" href="#id15" id="more-advanced-topics" name="more-advanced-topics">More advanced topics</a></h1>
-<div class="section">
-<h2><a class="toc-backref" href="#id16" id="hooks-and-environment-variables" name="hooks-and-environment-variables"><span id="hooks"></span>Hooks and environment variables</a></h2>
-<p>Normally, LLVMC executes programs from the system <tt class="docutils literal"><span class="pre">PATH</span></tt>. Sometimes,
-this is not sufficient: for example, we may want to specify tool paths
-or names in the configuration file. This can be easily achieved via
-the hooks mechanism. To write your own hooks, just add their
-definitions to the <tt class="docutils literal"><span class="pre">PluginMain.cpp</span></tt> or drop a <tt class="docutils literal"><span class="pre">.cpp</span></tt> file into the
-your plugin directory. Hooks should live in the <tt class="docutils literal"><span class="pre">hooks</span></tt> namespace
-and have the signature <tt class="docutils literal"><span class="pre">std::string</span> <span class="pre">hooks::MyHookName</span> <span class="pre">([const</span> <span class="pre">char*</span>
-<span class="pre">Arg0</span> <span class="pre">[</span> <span class="pre">const</span> <span class="pre">char*</span> <span class="pre">Arg2</span> <span class="pre">[,</span> <span class="pre">...]]])</span></tt>. They can be used from the
-<tt class="docutils literal"><span class="pre">cmd_line</span></tt> tool property:</p>
+<div class="section" id="more-advanced-topics">
+<h1><a class="toc-backref" href="#id18">More advanced topics</a></h1>
+<div class="section" id="hooks-and-environment-variables">
+<span id="hooks"></span><h2><a class="toc-backref" href="#id19">Hooks and environment variables</a></h2>
+<p>Normally, LLVMC searches for programs in the system <tt class="docutils literal">PATH</tt>. Sometimes, this is
+not sufficient: for example, we may want to specify tool paths or names in the
+configuration file. This can be achieved via the hooks mechanism. To write your
+own hooks, add their definitions to the <tt class="docutils literal">Hooks.cpp</tt> or drop a <tt class="docutils literal">.cpp</tt> file
+into your driver directory. Hooks should live in the <tt class="docutils literal">hooks</tt> namespace and
+have the signature <tt class="docutils literal"><span class="pre">std::string</span> <span class="pre">hooks::MyHookName</span> ([const char* Arg0 [ const
+char* Arg2 [, <span class="pre">...]]])</span></tt>. They can be used from the <tt class="docutils literal">command</tt> tool property:</p>
<pre class="literal-block">
-(cmd_line "$CALL(MyHook)/path/to/file -o $CALL(AnotherHook)")
+(command "$CALL(MyHook)/path/to/file -o $CALL(AnotherHook)")
</pre>
<p>To pass arguments to hooks, use the following syntax:</p>
<pre class="literal-block">
-(cmd_line "$CALL(MyHook, 'Arg1', 'Arg2', 'Arg # 3')/path/to/file -o1 -o2")
+(command "$CALL(MyHook, 'Arg1', 'Arg2', 'Arg # 3')/path/to/file -o1 -o2")
</pre>
<p>It is also possible to use environment variables in the same manner:</p>
<pre class="literal-block">
-(cmd_line "$ENV(VAR1)/path/to/file -o $ENV(VAR2)")
+(command "$ENV(VAR1)/path/to/file -o $ENV(VAR2)")
</pre>
<p>To change the command line string based on user-provided options use
-the <tt class="docutils literal"><span class="pre">case</span></tt> expression (documented <a class="reference" href="#case">above</a>):</p>
+the <tt class="docutils literal">case</tt> expression (documented <a class="reference internal" href="#case">above</a>):</p>
<pre class="literal-block">
-(cmd_line
+(command
(case
(switch_on "E"),
"llvm-g++ -E -x c $INFILE -o $OUTFILE",
"llvm-g++ -c -x c $INFILE -o $OUTFILE -emit-llvm"))
</pre>
</div>
-<div class="section">
-<h2><a class="toc-backref" href="#id17" id="how-plugins-are-loaded" name="how-plugins-are-loaded"><span id="priorities"></span>How plugins are loaded</a></h2>
-<p>It is possible for LLVMC plugins to depend on each other. For example,
-one can create edges between nodes defined in some other plugin. To
-make this work, however, that plugin should be loaded first. To
-achieve this, the concept of plugin priority was introduced. By
-default, every plugin has priority zero; to specify the priority
-explicitly, put the following line in your plugin's TableGen file:</p>
+<div class="section" id="debugging">
+<h2><a class="toc-backref" href="#id20">Debugging</a></h2>
+<p>When writing LLVMC-based drivers, it can be useful to get a visual view of the
+resulting compilation graph. This can be achieved via the command line option
+<tt class="docutils literal"><span class="pre">--view-graph</span></tt> (which assumes that <a class="reference external" href="http://www.graphviz.org/">Graphviz</a> and <a class="reference external" href="http://pages.cs.wisc.edu/~ghost/">Ghostview</a> are
+installed). There is also a <tt class="docutils literal"><span class="pre">--write-graph</span></tt> option that creates a Graphviz
+source file (<tt class="docutils literal"><span class="pre">compilation-graph.dot</span></tt>) in the current directory.</p>
+<p>Another useful <tt class="docutils literal">llvmc</tt> option is <tt class="docutils literal"><span class="pre">--check-graph</span></tt>. It checks the compilation
+graph for common errors like mismatched output/input language names, multiple
+default edges and cycles. When invoked with <tt class="docutils literal"><span class="pre">--check-graph</span></tt>, <tt class="docutils literal">llvmc</tt> doesn't
+perform any compilation tasks and returns the number of encountered errors as
+its status code. In the future, these checks will be performed at compile-time
+and this option will disappear.</p>
+</div>
+<div class="section" id="conditioning-on-the-executable-name">
+<h2><a class="toc-backref" href="#id21">Conditioning on the executable name</a></h2>
+<p>For now, the executable name (the value passed to the driver in <tt class="docutils literal">argv[0]</tt>) is
+accessible only in the C++ code (i.e. hooks). Use the following code:</p>
<pre class="literal-block">
-def Priority : PluginPriority<$PRIORITY_VALUE>;
-# Where PRIORITY_VALUE is some integer > 0
+namespace llvmc {
+extern const char* ProgramName;
+}
+
+namespace hooks {
+
+std::string MyHook() {
+//...
+if (strcmp(ProgramName, "mydriver") == 0) {
+ //...
+
+}
+
+} // end namespace hooks
</pre>
-<p>Plugins are loaded in order of their (increasing) priority, starting
-with 0. Therefore, the plugin with the highest priority value will be
-loaded last.</p>
-</div>
-<div class="section">
-<h2><a class="toc-backref" href="#id18" id="debugging" name="debugging">Debugging</a></h2>
-<p>When writing LLVMC plugins, it can be useful to get a visual view of
-the resulting compilation graph. This can be achieved via the command
-line option <tt class="docutils literal"><span class="pre">--view-graph</span></tt>. This command assumes that <a class="reference" href="http://www.graphviz.org/">Graphviz</a> and
-<a class="reference" href="http://pages.cs.wisc.edu/~ghost/">Ghostview</a> are installed. There is also a <tt class="docutils literal"><span class="pre">--write-graph</span></tt> option that
-creates a Graphviz source file (<tt class="docutils literal"><span class="pre">compilation-graph.dot</span></tt>) in the
-current directory.</p>
-<p>Another useful <tt class="docutils literal"><span class="pre">llvmc</span></tt> option is <tt class="docutils literal"><span class="pre">--check-graph</span></tt>. It checks the
-compilation graph for common errors like mismatched output/input
-language names, multiple default edges and cycles. These checks can't
-be performed at compile-time because the plugins can load code
-dynamically. When invoked with <tt class="docutils literal"><span class="pre">--check-graph</span></tt>, <tt class="docutils literal"><span class="pre">llvmc</span></tt> doesn't
-perform any compilation tasks and returns the number of encountered
-errors as its status code.</p>
+<p>In general, you're encouraged not to make the behaviour dependent on the
+executable file name, and use command-line switches instead. See for example how
+the <tt class="docutils literal">llvmc</tt> program behaves when it needs to choose the correct linker options
+(think <tt class="docutils literal">g++</tt> vs. <tt class="docutils literal">gcc</tt>).</p>
<hr />
<address>
<a href="http://jigsaw.w3.org/css-validator/check/referer">
<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) $
+Last modified: $Date$
</address></div>
</div>
</div>
projects / oota-llvm.git / blobdiff