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| author | Anton Korobeynikov <asl@math.spbu.ru> | 2008-06-09 04:15:49 +0000 |
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| committer | Anton Korobeynikov <asl@math.spbu.ru> | 2008-06-09 04:15:49 +0000 |
| commit | 74120313d0270fe594d22b1f46576621e153091d (patch) | |
| tree | f2d77c0ca7d0e6098cc0ba3cbe9caa45a811efc1 /docs | |
| parent | f3a4fea145f8e18316cd5f1f72b7616e56b3b716 (diff) | |
| download | llvm-74120313d0270fe594d22b1f46576621e153091d.tar.gz llvm-74120313d0270fe594d22b1f46576621e153091d.tar.bz2 llvm-74120313d0270fe594d22b1f46576621e153091d.tar.xz | |
Remove obsolete CompilerDriver.html and provie a new one, based on autogenerated file form
LLVMC-Reference.rst
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diff --git a/docs/CompilerDriver.html b/docs/CompilerDriver.html index 253f4719a6..80f8a49a5f 100644 --- a/docs/CompilerDriver.html +++ b/docs/CompilerDriver.html @@ -1,823 +1,411 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> -<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"> - <title>The LLVM Compiler Driver (llvmc)</title> - <link rel="stylesheet" href="llvm.css" type="text/css"> - <meta name="author" content="Reid Spencer"> - <meta name="description" - content="A description of the use and design of the LLVM Compiler Driver."> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> +<meta name="generator" content="Docutils 0.4: http://docutils.sourceforge.net/" /> +<title>Customizing LLVMC: Reference Manual</title> +<link rel="stylesheet" href="llvm.css" type="text/css" /> </head> <body> -<div class="doc_title">The LLVM Compiler Driver (llvmc)</div> -<p class="doc_warning">NOTE: This document is a work in progress!</p> -<ol> - <li><a href="#abstract">Abstract</a></li> - <li><a href="#introduction">Introduction</a> - <ol> - <li><a href="#purpose">Purpose</a></li> - <li><a href="#operation">Operation</a></li> - <li><a href="#phases">Phases</a></li> - <li><a href="#actions">Actions</a></li> - </ol> - </li> - <li><a href="#configuration">Configuration</a> - <ol> - <li><a href="#overview">Overview</a></li> - <li><a href="#filetypes">Configuration Files</a></li> - <li><a href="#syntax">Syntax</a></li> - <li><a href="#substitutions">Substitutions</a></li> - <li><a href="#sample">Sample Config File</a></li> - </ol> - <li><a href="#glossary">Glossary</a> -</ol> -<div class="doc_author"> -<p>Written by <a href="mailto:rspencer@x10sys.com">Reid Spencer</a> -</p> -</div> +<div class="document" id="customizing-llvmc-reference-manual"> -<!-- *********************************************************************** --> -<div class="doc_section"> <a name="abstract">Abstract</a></div> -<!-- *********************************************************************** --> -<div class="doc_text"> - <p>This document describes the requirements, design, and configuration of the - LLVM compiler driver, <tt>llvmc</tt>. The compiler driver knows about LLVM's - tool set and can be configured to know about a variety of compilers for - source languages. It uses this knowledge to execute the tools necessary - to accomplish general compilation, optimization, and linking tasks. The main - purpose of <tt>llvmc</tt> is to provide a simple and consistent interface to - all compilation tasks. This reduces the burden on the end user who can just - learn to use <tt>llvmc</tt> instead of the entire LLVM tool set and all the - source language compilers compatible with LLVM.</p> -</div> -<!-- *********************************************************************** --> -<div class="doc_section"> <a name="introduction">Introduction</a></div> -<!-- *********************************************************************** --> -<div class="doc_text"> - <p>The <tt>llvmc</tt> <a href="#def_tool">tool</a> is a configurable compiler - <a href="#def_driver">driver</a>. As such, it isn't a compiler, optimizer, - or a linker itself but it drives (invokes) other software that perform those - tasks. If you are familiar with the GNU Compiler Collection's <tt>gcc</tt> - tool, <tt>llvmc</tt> is very similar.</p> - <p>The following introductory sections will help you understand why this tool - is necessary and what it does.</p> -</div> +<div class="doc_title">Customizing LLVMC: Reference Manual</div> -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="purpose">Purpose</a></div> -<div class="doc_text"> - <p><tt>llvmc</tt> was invented to make compilation of user programs with - LLVM-based tools easier. To accomplish this, <tt>llvmc</tt> strives to:</p> - <ul> - <li>Be the single point of access to most of the LLVM tool set.</li> - <li>Hide the complexities of the LLVM tools through a single interface.</li> - <li>Provide a consistent interface for compiling all languages.</li> - </ul> - <p>Additionally, <tt>llvmc</tt> makes it easier to write a compiler for use - with LLVM, because it:</p> - <ul> - <li>Makes integration of existing non-LLVM tools simple.</li> - <li>Extends the capabilities of minimal compiler tools by optimizing their - output.</li> - <li>Reduces the number of interfaces a compiler writer must know about - before a working compiler can be completed (essentially only the VMCore - interfaces need to be understood).</li> - <li>Supports source language translator invocation via both dynamically - loadable shared objects and invocation of an executable.</li> - </ul> +<div class="doc_warning"> + <p>Note: This document is a work-in-progress. Additions and clarifications + are welcome.</p> </div> -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="operation">Operation</a></div> -<div class="doc_text"> - <p>At a high level, <tt>llvmc</tt> operation is very simple. The basic action - taken by <tt>llvmc</tt> is to simply invoke some tool or set of tools to fill - the user's request for compilation. Every execution of <tt>llvmc</tt>takes the - following sequence of steps:</p> - <dl> - <dt><b>Collect Command Line Options</b></dt> - <dd>The command line options provide the marching orders to <tt>llvmc</tt> - on what actions it should perform. This is the request the user is making - of <tt>llvmc</tt> and it is interpreted first. See the <tt>llvmc</tt> - <a href="CommandGuide/html/llvmc.html">manual page</a> for details on the - options.</dd> - <dt><b>Read Configuration Files</b></dt> - <dd>Based on the options and the suffixes of the filenames presented, a set - of configuration files are read to configure the actions <tt>llvmc</tt> will - take. Configuration files are provided by either LLVM or the - compiler tools that <tt>llvmc</tt> invokes. These files determine what - actions <tt>llvmc</tt> will take in response to the user's request. See - the section on <a href="#configuration">configuration</a> for more details. - </dd> - <dt><b>Determine Phases To Execute</b></dt> - <dd>Based on the command line options and configuration files, - <tt>llvmc</tt> determines the compilation <a href="#phases">phases</a> that - must be executed by the user's request. This is the primary work of - <tt>llvmc</tt>.</dd> - <dt><b>Determine Actions To Execute</b></dt> - <dd>Each <a href="#phases">phase</a> to be executed can result in the - invocation of one or more <a href="#actions">actions</a>. An action is - either a whole program or a function in a dynamically linked shared library. - In this step, <tt>llvmc</tt> determines the sequence of actions that must be - executed. Actions will always be executed in a deterministic order.</dd> - <dt><b>Execute Actions</b></dt> - <dd>The <a href="#actions">actions</a> necessary to support the user's - original request are executed sequentially and deterministically. All - actions result in either the invocation of a whole program to perform the - action or the loading of a dynamically linkable shared library and invocation - of a standard interface function within that library.</dd> - <dt><b>Termination</b></dt> - <dd>If any action fails (returns a non-zero result code), <tt>llvmc</tt> - also fails and returns the result code from the failing action. If - everything succeeds, <tt>llvmc</tt> will return a zero result code.</dd> - </dl> - <p><tt>llvmc</tt>'s operation must be simple, regular and predictable. - Developers need to be able to rely on it to take a consistent approach to - compilation. For example, the invocation:</p> - <code> - llvmc -O2 x.c y.c z.c -o xyz</code> - <p>must produce <i>exactly</i> the same results as:</p> - <pre><tt> - llvmc -O2 x.c -o x.o - llvmc -O2 y.c -o y.o - llvmc -O2 z.c -o z.o - llvmc -O2 x.o y.o z.o -o xyz</tt></pre> - <p>To accomplish this, <tt>llvmc</tt> uses a very simple goal oriented - procedure to do its work. The overall goal is to produce a functioning - executable. To accomplish this, <tt>llvmc</tt> always attempts to execute a - series of compilation <a href="#def_phase">phases</a> in the same sequence. - However, the user's options to <tt>llvmc</tt> can cause the sequence of phases - to start in the middle or finish early.</p> +<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. This makes it possible to adapt LLVMC for other +purposes - for example, as a build tool for game resources.</p> +<p>Because LLVMC employs TableGen <a class="footnote-reference" href="#id2" id="id1" name="id1">[1]</a> as its configuration language, you +need to be familiar with it to customize LLVMC.</p> +<div class="contents topic"> +<ul class="simple"> +<li><a class="reference" href="#compiling-with-llvmc" id="id3" name="id3">Compiling with LLVMC</a></li> +<li><a class="reference" href="#predefined-options" id="id4" name="id4">Predefined options</a></li> +<li><a class="reference" href="#customizing-llvmc-the-compilation-graph" id="id5" name="id5">Customizing LLVMC: the compilation graph</a></li> +<li><a class="reference" href="#writing-a-tool-description" id="id6" name="id6">Writing a tool description</a></li> +<li><a class="reference" href="#option-list-specifying-all-options-in-a-single-place" id="id7" name="id7">Option list - specifying all options in a single place</a></li> +<li><a class="reference" href="#using-hooks-and-environment-variables-in-the-cmd-line-property" id="id8" name="id8">Using hooks and environment variables in the <tt class="docutils literal"><span class="pre">cmd_line</span></tt> property</a></li> +<li><a class="reference" href="#conditional-evaluation-the-case-expression" id="id9" name="id9">Conditional evaluation: the <tt class="docutils literal"><span class="pre">case</span></tt> expression</a></li> +<li><a class="reference" href="#language-map" id="id10" name="id10">Language map</a></li> +<li><a class="reference" href="#references" id="id11" name="id11">References</a></li> +</ul> </div> -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="phases"></a>Phases </div> -<div class="doc_text"> - <p><tt>llvmc</tt> breaks every compilation task into the following five - distinct phases:</p> - <dl><dt><b>Preprocessing</b></dt><dd>Not all languages support preprocessing; - but for those that do, this phase can be invoked. This phase is for - languages that provide combining, filtering, or otherwise altering with the - source language input before the translator parses it. Although C and C++ - are the most common users of this phase, other languages may provide their - own preprocessor (whether its the C pre-processor or not).</dd> - </dl> - <dl><dt><b>Translation</b></dt><dd>The translation phase converts the source - language input into something that LLVM can interpret and use for - downstream phases. The translation is essentially from "non-LLVM form" to - "LLVM form".</dd> - </dl> - <dl><dt><b>Optimization</b></dt><dd>Once an LLVM Module has been obtained from - the translation phase, the program enters the optimization phase. This phase - attempts to optimize all of the input provided on the command line according - to the options provided.</dd> - </dl> - <dl><dt><b>Linking</b></dt><dd>The inputs are combined to form a complete - program.</dd> - </dl> - <p>The following table shows the inputs, outputs, and command line options - applicable to each phase.</p> - <table> - <tr> - <th style="width: 10%">Phase</th> - <th style="width: 25%">Inputs</th> - <th style="width: 25%">Outputs</th> - <th style="width: 40%">Options</th> - </tr> - <tr><td><b>Preprocessing</b></td> - <td class="td_left"><ul><li>Source Language File</li></ul></td> - <td class="td_left"><ul><li>Source Language File</li></ul></td> - <td class="td_left"><dl> - <dt><tt>-E</tt></dt> - <dd>Stops the compilation after preprocessing</dd> - </dl></td> - </tr> - <tr> - <td><b>Translation</b></td> - <td class="td_left"><ul> - <li>Source Language File</li> - </ul></td> - <td class="td_left"><ul> - <li>LLVM Assembly</li> - <li>LLVM Bitcode</li> - <li>LLVM C++ IR</li> - </ul></td> - <td class="td_left"><dl> - <dt><tt>-c</tt></dt> - <dd>Stops the compilation after translation so that optimization and - linking are not done.</dd> - <dt><tt>-S</tt></dt> - <dd>Stops the compilation before object code is written so that only - assembly code remains.</dd> - </dl></td> - </tr> - <tr> - <td><b>Optimization</b></td> - <td class="td_left"><ul> - <li>LLVM Assembly</li> - <li>LLVM Bitcode</li> - </ul></td> - <td class="td_left"><ul> - <li>LLVM Bitcode</li> - </ul></td> - <td class="td_left"><dl> - <dt><tt>-Ox</tt> - <dd>This group of options controls the amount of optimization - performed.</dd> - </dl></td> - </tr> - <tr> - <td><b>Linking</b></td> - <td class="td_left"><ul> - <li>LLVM Bitcode</li> - <li>Native Object Code</li> - <li>LLVM Library</li> - <li>Native Library</li> - </ul></td> - <td class="td_left"><ul> - <li>LLVM Bitcode Executable</li> - <li>Native Executable</li> - </ul></td> - <td class="td_left"><dl> - <dt><tt>-L</tt></dt><dd>Specifies a path for library search.</dd> - <dt><tt>-l</tt></dt><dd>Specifies a library to link in.</dd> - </dl></td> - </tr> - </table> -</div> +<div class="doc_author">Written by Mikhail Glushenkov</div> -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="actions"></a>Actions</div> <div class="doc_text"> - <p>An action, with regard to <tt>llvmc</tt> is a basic operation that it takes - in order to fulfill the user's request. Each phase of compilation will invoke - zero or more actions in order to accomplish that phase.</p> - <p>Actions come in two forms:</p> - <ul> - <li>Invokable Executables</li> - <li>Functions in a shared library</li> - </ul> +<div class="doc_section"><a class="toc-backref" href="#id3" id="compiling-with-llvmc" name="compiling-with-llvmc">Compiling with LLVMC</a></div> +<p>LLVMC tries hard to be as compatible with <tt class="docutils literal"><span class="pre">gcc</span></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"> +$ # This works as expected: +$ llvmc2 -O3 -Wall hello.cpp +$ ./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> +<pre class="literal-block"> +$ llvmc2 -x c hello.cpp +$ # hello.cpp is really a C file +$ ./a.out +hello +</pre> +<p>On the other hand, when using LLVMC as a linker to combine several C++ +object files you should provide the <tt class="docutils literal"><span class="pre">--linker</span></tt> option since it's +impossible for LLVMC to choose the right linker in that case:</p> +<pre class="literal-block"> +$ llvmc2 -c hello.cpp +$ llvmc2 hello.o +[A lot of link-time errors skipped] +$ llvmc2 --linker=c++ hello.o +$ ./a.out +hello +</pre> </div> - -<!-- *********************************************************************** --> -<div class="doc_section"><a name="configuration">Configuration</a></div> -<!-- *********************************************************************** --> <div class="doc_text"> - <p>This section of the document describes the configuration files used by - <tt>llvmc</tt>. Configuration information is relatively static for a - given release of LLVM and a compiler tool. However, the details may - change from release to release of either. Users are encouraged to simply use - the various options of the <tt>llvmc</tt> command and ignore the configuration - of the tool. These configuration files are for compiler writers and LLVM - developers. Those wishing to simply use <tt>llvmc</tt> don't need to understand - this section but it may be instructive on how the tool works.</p> +<div class="doc_section"><a class="toc-backref" href="#id4" id="predefined-options" name="predefined-options">Predefined options</a></div> +<p>LLVMC has some built-in options that can't be overridden in the +configuration files:</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 +until the next -x option.</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">--view-graph</span></tt> - Show a graphical representation of the compilation +graph. 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> commands +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 the +Graphviz format. Hidden option, useful for debugging.</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> +<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="doc_subsection"><a name="overview"></a>Overview</div> <div class="doc_text"> -<p><tt>llvmc</tt> is highly configurable both on the command line and in -configuration files. The options it understands are generic, consistent and -simple by design. Furthermore, the <tt>llvmc</tt> options apply to the -compilation of any LLVM enabled programming language. To be enabled as a -supported source language compiler, a compiler writer must provide a -configuration file that tells <tt>llvmc</tt> how to invoke the compiler -and what its capabilities are. The purpose of the configuration files then -is to allow compiler writers to specify to <tt>llvmc</tt> how the compiler -should be invoked. Users may but are not advised to alter the compiler's -<tt>llvmc</tt> configuration.</p> - -<p>Because <tt>llvmc</tt> just invokes other programs, it must deal with the -available command line options for those programs regardless of whether they -were written for LLVM or not. Furthermore, not all compiler tools will -have the same capabilities. Some compiler tools will simply generate LLVM assembly -code, others will be able to generate fully optimized bitcode. In general, -<tt>llvmc</tt> doesn't make any assumptions about the capabilities or command -line options of a sub-tool. It simply uses the details found in the -configuration files and leaves it to the compiler writer to specify the -configuration correctly.</p> - -<p>This approach means that new compiler tools can be up and working very -quickly. As a first cut, a tool can simply compile its source to raw -(unoptimized) bitcode or LLVM assembly and <tt>llvmc</tt> can be configured -to pick up the slack (translate LLVM assembly to bitcode, optimize the -bitcode, generate native assembly, link, etc.). In fact, the compiler tools -need not use any LLVM libraries, and it could be written in any language -(instead of C++). The configuration data will allow the full range of -optimization, assembly, and linking capabilities that LLVM provides to be added -to these kinds of tools. Enabling the rapid development of front-ends is one -of the primary goals of <tt>llvmc</tt>.</p> - -<p>As a compiler tool matures, it may utilize the LLVM libraries and tools -to more efficiently produce optimized bitcode directly in a single compilation -and optimization program. In these cases, multiple tools would not be needed -and the configuration data for the compiler would change.</p> - -<p>Configuring <tt>llvmc</tt> to the needs and capabilities of a source language -compiler is relatively straight-forward. A compiler writer must provide a -definition of what to do for each of the five compilation phases for each of -the optimization levels. The specification consists simply of prototypical -command lines into which <tt>llvmc</tt> can substitute command line -arguments and file names. Note that any given phase can be completely blank if -the source language's compiler combines multiple phases into a single program. -For example, quite often pre-processing, translation, and optimization are -combined into a single program. The specification for such a compiler would have -blank entries for pre-processing and translation but a full command line for -optimization.</p> -</div> - -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="filetypes">Configuration Files</a></div> -<div class="doc_subsubsection"><a name="filecontents">File Contents</a></div> -<div class="doc_text"> - <p>Each configuration file provides the details for a single source language - that is to be compiled. This configuration information tells <tt>llvmc</tt> - how to invoke the language's pre-processor, translator, optimizer, assembler - and linker. Note that a given source language needn't provide all these tools - as many of them exist in llvm currently.</p> +<div class="doc_section"><a class="toc-backref" href="#id5" id="customizing-llvmc-the-compilation-graph" name="customizing-llvmc-the-compilation-graph">Customizing LLVMC: the compilation graph</a></div> +<p>At the time of writing LLVMC does not support on-the-fly reloading of +configuration, so to customize LLVMC you'll have to recompile the +source code (which lives under <tt class="docutils literal"><span class="pre">$LLVM_DIR/tools/llvmc2</span></tt>). The +default configuration files are <tt class="docutils literal"><span class="pre">Common.td</span></tt> (contains common +definitions, don't forget to <tt class="docutils literal"><span class="pre">include</span></tt> it in your configuration +files), <tt class="docutils literal"><span class="pre">Tools.td</span></tt> (tool descriptions) and <tt class="docutils literal"><span class="pre">Graph.td</span></tt> (compilation +graph definition).</p> +<p>To compile LLVMC with your own configuration file (say,``MyGraph.td``), +run <tt class="docutils literal"><span class="pre">make</span></tt> like this:</p> +<pre class="literal-block"> +$ cd $LLVM_DIR/tools/llvmc2 +$ make GRAPH=MyGraph.td TOOLNAME=my_llvmc +</pre> +<p>This will build an executable named <tt class="docutils literal"><span class="pre">my_llvmc</span></tt>. There are also +several sample configuration files in the <tt class="docutils literal"><span class="pre">llvmc2/examples</span></tt> +subdirectory that should help to get you started.</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"><span class="pre">Graph.td</span></tt>) is +just a list of edges:</p> +<pre class="literal-block"> +def CompilationGraph : CompilationGraph<[ + Edge<root, llvm_gcc_c>, + Edge<root, llvm_gcc_assembler>, + ... + + Edge<llvm_gcc_c, llc>, + Edge<llvm_gcc_cpp, llc>, + ... + + OptionalEdge<llvm_gcc_c, opt, [(switch_on "opt")]>, + OptionalEdge<llvm_gcc_cpp, opt, [(switch_on "opt")]>, + ... + + OptionalEdge<llvm_gcc_assembler, llvm_gcc_cpp_linker, + (case (input_languages_contain "c++"), (inc_weight), + (or (parameter_equals "linker", "g++"), + (parameter_equals "linker", "c++")), (inc_weight))>, + ... + + ]>; +</pre> +<p>As you can see, the edges can be either default or optional, where +optional edges are differentiated by sporting a <tt class="docutils literal"><span class="pre">case</span></tt> expression +used to calculate the edge's weight.</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.</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>To get a visual representation of the compilation graph (useful for +debugging), run <tt class="docutils literal"><span class="pre">llvmc2</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> </div> - -<!-- _______________________________________________________________________ --> -<div class="doc_subsubsection"><a name="dirsearch">Directory Search</a></div> <div class="doc_text"> - <p><tt>llvmc</tt> always looks for files of a specific name. It uses the - first file with the name its looking for by searching directories in the - following order:<br/> - <ol> - <li>Any directory specified by the <tt>-config-dir</tt> option will be - checked first.</li> - <li>If the environment variable LLVM_CONFIG_DIR is set, and it contains - the name of a valid directory, that directory will be searched next.</li> - <li>If the user's home directory (typically <tt>/home/user</tt> contains - a sub-directory named <tt>.llvm</tt> and that directory contains a - sub-directory named <tt>etc</tt> then that directory will be tried - next.</li> - <li>If the LLVM installation directory (typically <tt>/usr/local/llvm</tt> - contains a sub-directory named <tt>etc</tt> then that directory will be - tried last.</li> - <li>A standard "system" directory will be searched next. This is typically - <tt>/etc/llvm</tt> on UNIX™ and <tt>C:\WINNT</tt> on Microsoft - Windows™.</li> - <li>If the configuration file sought still can't be found, <tt>llvmc</tt> - will print an error message and exit.</li> - </ol> - <p>The first file found in this search will be used. Other files with the - same name will be ignored even if they exist in one of the subsequent search - locations.</p> +<div class="doc_section"><a class="toc-backref" href="#id6" id="writing-a-tool-description" name="writing-a-tool-description">Writing a tool description</a></div> +<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">Tools.td</span></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 $OUTFILE -emit-llvm"), + (sink) + ]>; +</pre> +<p>This defines a new tool called <tt class="docutils literal"><span class="pre">llvm_gcc_cpp</span></tt>, which is an alias for +<tt class="docutils literal"><span class="pre">llvm-g++</span></tt>. As you can see, a tool definition is just a list of +properties; most of them should be self-explanatory. The <tt class="docutils literal"><span class="pre">sink</span></tt> +property means that this tool should be passed all command-line +options that lack explicit descriptions.</p> +<p>The complete list of the currently implemented tool properties follows:</p> +<ul class="simple"> +<li>Possible tool properties:<ul> +<li><tt class="docutils literal"><span class="pre">in_language</span></tt> - input language name.</li> +<li><tt class="docutils literal"><span class="pre">out_language</span></tt> - output language name.</li> +<li><tt class="docutils literal"><span class="pre">output_suffix</span></tt> - output file suffix.</li> +<li><tt class="docutils literal"><span class="pre">cmd_line</span></tt> - the actual command used to run the tool. You can +use <tt class="docutils literal"><span class="pre">$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 (more on this below).</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> +</ul> +</li> +</ul> +<p>The next tool definition is slightly more complex:</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"), + (join), + (prefix_list_option "L", (forward), + (help "add a directory to link path")), + (prefix_list_option "l", (forward), + (help "search a library when linking")), + (prefix_list_option "Wl", (unpack_values), + (help "pass options to linker")) + ]>; +</pre> +<p>This tool has a "join" property, which means that it behaves like a +linker. This tool also defines several command-line options: <tt class="docutils literal"><span class="pre">-l</span></tt>, +<tt class="docutils literal"><span class="pre">-L</span></tt> and <tt class="docutils literal"><span class="pre">-Wl</span></tt> which have their usual meaning. An option has two +attributes: a name and a (possibly empty) list of properties. All +currently implemented option types and properties are described below:</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, for example <tt class="docutils literal"><span class="pre">-time</span></tt>.</li> +<li><tt class="docutils literal"><span class="pre">parameter_option</span></tt> - option that takes an argument, for example +<tt class="docutils literal"><span class="pre">-std=c99</span></tt>;</li> +<li><tt class="docutils literal"><span class="pre">parameter_list_option</span></tt> - same as the above, but more than one +occurence of the option 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 parameter value are not separated.</li> +<li><tt class="docutils literal"><span class="pre">prefix_list_option</span></tt> - same as the above, but more than one +occurence 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 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> +</ul> +</blockquote> +</li> +<li><p class="first">Possible option properties:</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.</li> +<li><tt class="docutils literal"><span class="pre">forward</span></tt> - forward this option unchanged.</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">(switch</span> <span class="pre">"E",</span> <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 phase.</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.</li> +<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> output.</li> +<li><tt class="docutils literal"><span class="pre">required</span></tt> - this option is obligatory.</li> +</ul> +</blockquote> +</li> +</ul> </div> - -<div class="doc_subsubsection"><a name="filenames">File Names</a></div> <div class="doc_text"> - <p>In the directories searched, each configuration file is given a specific - name to foster faster lookup (so llvmc doesn't have to do directory searches). - The name of a given language specific configuration file is simply the same - as the suffix used to identify files containing source in that language. - For example, a configuration file for C++ source might be named - <tt>cpp</tt>, <tt>C</tt>, or <tt>cxx</tt>. For languages that support multiple - file suffixes, multiple (probably identical) files (or symbolic links) will - need to be provided.</p> +<div class="doc_section"><a class="toc-backref" href="#id7" id="option-list-specifying-all-options-in-a-single-place" name="option-list-specifying-all-options-in-a-single-place">Option list - specifying all options in a single place</a></div> +<p>It can be handy to have all information about options gathered in a +single place to provide an overview. This can be achieved by using a +so-called <tt class="docutils literal"><span class="pre">OptionList</span></tt>:</p> +<pre class="literal-block"> +def Options : OptionList<[ +(switch_option "E", (help "Help string")), +(alias_option "quiet", "q") +... +]>; +</pre> +<p><tt class="docutils literal"><span class="pre">OptionList</span></tt> is also a good place to specify option aliases.</p> +<p>Tool-specific option properties like <tt class="docutils literal"><span class="pre">append_cmd</span></tt> have (obviously) +no meaning in the context of <tt class="docutils literal"><span class="pre">OptionList</span></tt>, so the only properties +allowed there are <tt class="docutils literal"><span class="pre">help</span></tt> and <tt class="docutils literal"><span class="pre">required</span></tt>.</p> +<p>Option lists are used at the file scope. See file +<tt class="docutils literal"><span class="pre">examples/Clang.td</span></tt> for an example of <tt class="docutils literal"><span class="pre">OptionList</span></tt> usage.</p> </div> - -<div class="doc_subsubsection"><a name="whatgetsread">What Gets Read</a></div> <div class="doc_text"> - <p>Which configuration files are read depends on the command line options and - the suffixes of the file names provided on <tt>llvmc</tt>'s command line. Note - that the <tt>-x LANGUAGE</tt> option alters the language that <tt>llvmc</tt> - uses for the subsequent files on the command line. Only the configuration - files actually needed to complete <tt>llvmc</tt>'s task are read. Other - language specific files will be ignored.</p> +<div class="doc_section"><a class="toc-backref" href="#id8" id="using-hooks-and-environment-variables-in-the-cmd-line-property" name="using-hooks-and-environment-variables-in-the-cmd-line-property">Using hooks and environment variables in the <tt class="docutils literal"><span class="pre">cmd_line</span></tt> property</a></div> +<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 names +in the configuration file. This can be achieved via the mechanism of +hooks - to compile LLVMC with your hooks, just drop a .cpp file into +<tt class="docutils literal"><span class="pre">tools/llvmc2</span></tt> 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">(void)</span></tt>. They can be used from the <tt class="docutils literal"><span class="pre">cmd_line</span></tt> tool property:</p> +<pre class="literal-block"> +(cmd_line "$CALL(MyHook)/path/to/file -o $CALL(AnotherHook)") +</pre> +<p>It is also possible to use environment variables in the same manner:</p> +<pre class="literal-block"> +(cmd_line "$ENV(VAR1)/path/to/file -o $ENV(VAR2)") +</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 below):</p> +<pre class="literal-block"> +(cmd_line + (case + (switch_on "E"), + "llvm-g++ -E -x c $INFILE -o $OUTFILE", + (default), + "llvm-g++ -c -x c $INFILE -o $OUTFILE -emit-llvm")) +</pre> </div> - -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="syntax"></a>Syntax</div> <div class="doc_text"> - <p>The syntax of the configuration files is very simple and somewhat - compatible with Java's property files. Here are the syntax rules:</p> - <ul> - <li>The file encoding is ASCII.</li> - <li>The file is line oriented. There should be one configuration definition - per line. Lines are terminated by the newline (0x0A) and/or carriage return - characters (0x0D)</li> - <li>A backslash (<tt>\</tt>) before a newline causes the newline to be - ignored. This is useful for line continuation of long definitions. A - backslash anywhere else is recognized as a backslash.</li> - <li>A configuration item consists of a name, an <tt>=</tt> and a value.</li> - <li>A name consists of a sequence of identifiers separated by period.</li> - <li>An identifier consists of specific keywords made up of only lower case - and upper case letters (e.g. <tt>lang.name</tt>).</li> - <li>Values come in four flavors: booleans, integers, commands and - strings.</li> - <li>Valid "false" boolean values are <tt>false False FALSE no No NO - off Off</tt> and <tt>OFF</tt>.</li> - <li>Valid "true" boolean values are <tt>true True TRUE yes Yes YES - on On</tt> and <tt>ON</tt>.</li> - <li>Integers are simply sequences of digits.</li> - <li>Commands start with a program name and are followed by a sequence of - words that are passed to that program as command line arguments. Program - arguments that begin and end with the <tt>%</tt> sign will have their value - substituted. Program names beginning with <tt>/</tt> are considered to be - absolute. Otherwise the <tt>PATH</tt> will be applied to find the program to - execute.</li> - <li>Strings are composed of multiple sequences of characters from the - character class <tt>[-A-Za-z0-9_:%+/\\|,]</tt> separated by white - space.</li> - <li>White space on a line is folded. Multiple blanks or tabs will be - reduced to a single blank.</li> - <li>White space before the configuration item's name is ignored.</li> - <li>White space on either side of the <tt>=</tt> is ignored.</li> - <li>White space in a string value is used to separate the individual - components of the string value but otherwise ignored.</li> - <li>Comments are introduced by the <tt>#</tt> character. Everything after a - <tt>#</tt> and before the end of line is ignored.</li> - </ul> +<div class="doc_section"><a class="toc-backref" href="#id9" id="conditional-evaluation-the-case-expression" name="conditional-evaluation-the-case-expression">Conditional evaluation: the <tt class="docutils literal"><span class="pre">case</span></tt> expression</a></div> +<p>The 'case' construct can be used to calculate weights of the optional +edges and to choose between several alternative command line strings +in the <tt class="docutils literal"><span class="pre">cmd_line</span></tt> tool property. It 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> +<p>Examples:</p> +<pre class="literal-block"> +// Increases edge weight by 5 if "-A" is provided on the +// command-line, and by 5 more if "-B" is also provided. +(case + (switch_on "A"), (inc_weight 5), + (switch_on "B"), (inc_weight 5)) + +// Evaluates to "cmdline1" if option "-A" is provided on the +// command line, otherwise to "cmdline2" +(case + (switch_on "A"), "cmdline1", + (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>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> +<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 option is +provided by the user. Example: <tt class="docutils literal"><span class="pre">(switch_on</span> <span class="pre">"opt")</span></tt>. Note that +you have to define all possible command-line options separately in +the tool descriptions. See the next doc_text for the discussion of +different kinds of command-line options.</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 +includes 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 +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 language of the input +file equals to the argument. Valid only when using <tt class="docutils literal"><span class="pre">case</span></tt> +expression in a <tt class="docutils literal"><span class="pre">cmd_line</span></tt> tool property. 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">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> +</ul> +</li> +</ul> </div> - -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="items">Configuration Items</a></div> <div class="doc_text"> - <p>The table below provides definitions of the allowed configuration items - that may appear in a configuration file. Every item has a default value and - does not need to appear in the configuration file. Missing items will have the - default value. Each identifier may appear as all lower case, first letter - capitalized or all upper case.</p> - <table> - <tbody> - <tr> - <th>Name</th> - <th>Value Type</th> - <th>Description</th> - <th>Default</th> - </tr> - <tr><td colspan="4"><h4>LLVMC ITEMS</h4></td></tr> - <tr> - <td><b>version</b></td> - <td>string</td> - <td class="td_left">Provides the version string for the contents of this - configuration file. What is accepted as a legal configuration file - will change over time and this item tells <tt>llvmc</tt> which version - should be expected.</td> - <td><i>b</i></td> - </tr> - <tr><td colspan="4"><h4>LANG ITEMS</h4></td></tr> - <tr> - <td><b>lang.name</b></td> - <td>string</td> - <td class="td_left">Provides the common name for a language definition. - For example "C++", "Pascal", "FORTRAN", etc.</td> - <td><i>blank</i></td> - </tr> - <tr> - <td><b>lang.opt1</b></td> - <td>string</td> - <td class="td_left">Specifies the parameters to give the optimizer when - <tt>-O1</tt> is specified on the <tt>llvmc</tt> command line.</td> - <td><tt>-simplifycfg -instcombine -mem2reg</tt></td> - </tr> - <tr> - <td><b>lang.opt2</b></td> - <td>string</td> - <td class="td_left">Specifies the parameters to give the optimizer when - <tt>-O2</tt> is specified on the <tt>llvmc</tt> command line.</td> - <td><i>TBD</i></td> - </tr> - <tr> - <td><b>lang.opt3</b></td> - <td>string</td> - <td class="td_left">Specifies the parameters to give the optimizer when - <tt>-O3</tt> is specified on the <tt>llvmc</tt> command line.</td> - <td><i>TBD</i></td> - </tr> - <tr> - <td><b>lang.opt4</b></td> - <td>string</td> - <td class="td_left">Specifies the parameters to give the optimizer when - <tt>-O4</tt> is specified on the <tt>llvmc</tt> command line.</td> - <td><i>TBD</i></td> - </tr> - <tr> - <td><b>lang.opt5</b></td> - <td>string</td> - <td class="td_left">Specifies the parameters to give the optimizer when - <tt>-O5</tt> is specified on the <tt>llvmc</tt> command line.</td> - <td><i>TBD</i></td> - </tr> - <tr><td colspan="4"><h4>PREPROCESSOR ITEMS</h4></td></tr> - <tr> - <td><b>preprocessor.command</b></td> - <td>command</td> - <td class="td_left">This provides the command prototype that will be used - to run the preprocessor. This is generally only used with the - <tt>-E</tt> option.</td> - <td><blank></td> - </tr> - <tr> - <td><b>preprocessor.required</b></td> - <td>boolean</td> - <td class="td_left">This item specifies whether the pre-processing phase - is required by the language. If the value is true, then the - <tt>preprocessor.command</tt> value must not be blank. With this option, - <tt>llvmc</tt> will always run the preprocessor as it assumes that the - translation and optimization phases don't know how to pre-process their - input.</td> - <td>false</td> - </tr> - <tr><td colspan="4"><h4>TRANSLATOR ITEMS</h4></td></tr> - <tr> - <td><b>translator.command</b></td> - <td>command</td> - <td class="td_left">This provides the command prototype that will be used - to run the translator. Valid substitutions are <tt>%in%</tt> for the - input file and <tt>%out%</tt> for the output file.</td> - <td><blank></td> - </tr> - <tr> - <td><b>translator.output</b></td> - <td><tt>bitcode</tt> or <tt>assembly</tt></td> - <td class="td_left">This item specifies the kind of output the language's - translator generates.</td> - <td><tt>bitcode</tt></td> - </tr> - <tr> - <td><b>translator.preprocesses</b></td> - <td>boolean</td> - <td class="td_left">Indicates that the translator also preprocesses. If - this is true, then <tt>llvmc</tt> will skip the pre-processing phase - whenever the final phase is not pre-processing.</td> - <td><tt>false</tt></td> - </tr> - <tr><td colspan="4"><h4>OPTIMIZER ITEMS</h4></td></tr> - <tr> - <td><b>optimizer.command</b></td> - <td>command</td> - <td class="td_left">This provides the command prototype that will be used - to run the optimizer. Valid substitutions are <tt>%in%</tt> for the - input file and <tt>%out%</tt> for the output file.</td> - <td><blank></td> - </tr> - <tr> - <td><b>optimizer.output</b></td> - <td><tt>bitcode</tt> or <tt>assembly</tt></td> - <td class="td_left">This item specifies the kind of output the language's - optimizer generates. Valid values are "assembly" and "bitcode"</td> - <td><tt>bitcode</tt></td> - </tr> - <tr> - <td><b>optimizer.preprocesses</b></td> - <td>boolean</td> - <td class="td_left">Indicates that the optimizer also preprocesses. If - this is true, then <tt>llvmc</tt> will skip the pre-processing phase - whenever the final phase is optimization or later.</td> - <td><tt>false</tt></td> - </tr> - <tr> - <td><b>optimizer.translates</b></td> - <td>boolean</td> - <td class="td_left">Indicates that the optimizer also translates. If - this is true, then <tt>llvmc</tt> will skip the translation phase - whenever the final phase is optimization or later.</td> - <td><tt>false</tt></td> - </tr> - <tr><td colspan="4"><h4>ASSEMBLER ITEMS</h4></td></tr> - <tr> - <td><b>assembler.command</b></td> - <td>command</td> - <td class="td_left">This provides the command prototype that will be used - to run the assembler. Valid substitutions are <tt>%in%</tt> for the - input file and <tt>%out%</tt> for the output file.</td> - <td><blank></td> - </tr> - </tbody> - </table> +<div class="doc_section"><a class="toc-backref" href="#id10" id="language-map" name="language-map">Language map</a></div> +<p>One last thing that you will need to modify when adding support for a +new language to LLVMC is 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 is +located in the file <tt class="docutils literal"><span class="pre">Tools.td</span></tt> and looks like this:</p> +<pre class="literal-block"> +def LanguageMap : LanguageMap< + [LangToSuffixes<"c++", ["cc", "cp", "cxx", "cpp", "CPP", "c++", "C"]>, + LangToSuffixes<"c", ["c"]>, + ... + ]>; +</pre> </div> - -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="substitutions">Substitutions</a></div> <div class="doc_text"> - <p>On any configuration item that ends in <tt>command</tt>, you must - specify substitution tokens. Substitution tokens begin and end with a percent - sign (<tt>%</tt>) and are replaced by the corresponding text. Any substitution - token may be given on any <tt>command</tt> line but some are more useful than - others. In particular each command <em>should</em> have both an <tt>%in%</tt> - and an <tt>%out%</tt> substitution. The table below provides definitions of - each of the allowed substitution tokens.</p> - <table> - <tbody> - <tr> - <th>Substitution Token</th> - <th>Replacement Description</th> - </tr> - <tr> - <td><tt>%args%</tt></td> - <td class="td_left">Replaced with all the tool-specific arguments given - to <tt>llvmc</tt> via the <tt>-T</tt> set of options. This just allows - you to place these arguments in the correct place on the command line. - If the <tt>%args%</tt> option does not appear on your command line, - then you are explicitly disallowing the <tt>-T</tt> option for your - tool. - </td> - <tr> - <td><tt>%force%</tt></td> - <td class="td_left">Replaced with the <tt>-f</tt> option if it was - specified on the <tt>llvmc</tt> command line. This is intended to tell - the compiler tool to force the overwrite of output files. - </td> - </tr> - <tr> - <td><tt>%in%</tt></td> - <td class="td_left">Replaced with the full path of the input file. You - needn't worry about the cascading of file names. <tt>llvmc</tt> will - create temporary files and ensure that the output of one phase is the - input to the next phase.</td> - </tr> - <tr> - <td><tt>%opt%</tt></td> - <td class="td_left">Replaced with the optimization options for the - tool. If the tool understands the <tt>-O</tt> options then that will - be passed. Otherwise, the <tt>lang.optN</tt> series of configuration - items will specify which arguments are to be given.</td> - </tr> - <tr> - <td><tt>%out%</tt></td> - <td class="td_left">Replaced with the full path of the output file. - Note that this is not necessarily the output file specified with the - <tt>-o</tt> option on <tt>llvmc</tt>'s command line. It might be a - temporary file that will be passed to a subsequent phase's input. - </td> - </tr> - <tr> - <td><tt>%stats%</tt></td> - <td class="td_left">If your command accepts the <tt>-stats</tt> option, - use this substitution token. If the user requested <tt>-stats</tt> - from the <tt>llvmc</tt> command line then this token will be replaced - with <tt>-stats</tt>, otherwise it will be ignored. - </td> - </tr> - <tr> - <td><tt>%target%</tt></td> - <td class="td_left">Replaced with the name of the target "machine" for - which code should be generated. The value used here is taken from the - <tt>llvmc</tt> option <tt>-march</tt>. - </td> - </tr> - <tr> - <td><tt>%time%</tt></td> - <td class="td_left">If your command accepts the <tt>-time-passes</tt> - option, use this substitution token. If the user requested - <tt>-time-passes</tt> from the <tt>llvmc</tt> command line then this - token will be replaced with <tt>-time-passes</tt>, otherwise it will - be ignored. - </td> - </tr> - </tbody> - </table> +<div class="doc_section"><a class="toc-backref" href="#id11" id="references" name="references">References</a></div> +<table class="docutils footnote" frame="void" id="id2" rules="none"> +<colgroup><col class="label" /><col /></colgroup> +<tbody valign="top"> +<tr><td class="label"><a class="fn-backref" href="#id1" name="id2">[1]</a></td><td>TableGen Fundamentals +<a class="reference" href="http://llvm.cs.uiuc.edu/docs/TableGenFundamentals.html">http://llvm.cs.uiuc.edu/docs/TableGenFundamentals.html</a></td></tr> +</tbody> +</table> </div> - -<!-- _______________________________________________________________________ --> -<div class="doc_subsection"><a name="sample">Sample Config File</a></div> -<div class="doc_text"> - <p>Since an example is always instructive, here's how the Stacker language - configuration file looks.</p> - <pre><tt> -# Stacker Configuration File For llvmc - -########################################################## -# Language definitions -########################################################## - lang.name=Stacker - lang.opt1=-simplifycfg -instcombine -mem2reg - lang.opt2=-simplifycfg -instcombine -mem2reg -load-vn \ - -gcse -dse -scalarrepl -sccp - lang.opt3=-simplifycfg -instcombine -mem2reg -load-vn \ - -gcse -dse -scalarrepl -sccp -branch-combine -adce \ - -globaldce -inline -licm - lang.opt4=-simplifycfg -instcombine -mem2reg -load-vn \ - -gcse -dse -scalarrepl -sccp -ipconstprop \ - -branch-combine -adce -globaldce -inline -licm - lang.opt5=-simplifycfg -instcombine -mem2reg --load-vn \ - -gcse -dse scalarrepl -sccp -ipconstprop \ - -branch-combine -adce -globaldce -inline -licm \ - -block-placement - -########################################################## -# Pre-processor definitions -########################################################## - - # Stacker doesn't have a preprocessor but the following - # allows the -E option to be supported - preprocessor.command=cp %in% %out% - preprocessor.required=false - -########################################################## -# Translator definitions -########################################################## - - # To compile stacker source, we just run the stacker - # compiler with a default stack size of 2048 entries. - translator.command=stkrc -s 2048 %in% -o %out% %time% \ - %stats% %force% %args% - - # stkrc doesn't preprocess but we set this to true so - # that we don't run the cp command by default. - translator.preprocesses=true - - # The translator is required to run. - translator.required=true - - # stkrc doesn't handle the -On options - translator.output=bitcode - -########################################################## -# Optimizer definitions -########################################################## - - # For optimization, we use the LLVM "opt" program - optimizer.command=opt %in% -o %out% %opt% %time% %stats% \ - %force% %args% - - optimizer.required = true - - # opt doesn't translate - optimizer.translates = no - - # opt doesn't preprocess - optimizer.preprocesses=no - - # opt produces bitcode - optimizer.output = bc - -########################################################## -# Assembler definitions -########################################################## - assembler.command=llc %in% -o %out% %target% %time% %stats% -</tt></pre> -</div> - -<!-- *********************************************************************** --> -<div class="doc_section"><a name="glossary">Glossary</a></div> -<!-- *********************************************************************** --> -<div class="doc_text"> - <p>This document uses precise terms in reference to the various artifacts and - concepts related to compilation. The terms used throughout this document are - defined below.</p> - <dl> - <dt><a name="def_assembly"><b>assembly</b></a></dt> - <dd>A compilation <a href="#def_phase">phase</a> in which LLVM bitcode or - LLVM assembly code is assembled to a native code format (either target - specific aseembly language or the platform's native object file format). - </dd> - - <dt><a name="def_compiler"><b>compiler</b></a></dt> - <dd>Refers to any program that can be invoked by <tt>llvmc</tt> to accomplish - the work of one or more compilation <a href="#def_phase">phases</a>.</dd> - - <dt><a name="def_driver"><b>driver</b></a></dt> - <dd>Refers to <tt>llvmc</tt> itself.</dd> - - <dt><a name="def_linking"><b>linking</b></a></dt> - <dd>A compilation <a href="#def_phase">phase</a> in which LLVM bitcode files - and (optionally) native system libraries are combined to form a complete - executable program.</dd> - - <dt><a name="def_optimization"><b>optimization</b></a></dt> - <dd>A compilation <a href="#def_phase">phase</a> in which LLVM bitcode is - optimized.</dd> - - <dt><a name="def_phase"><b>phase</b></a></dt> - <dd>Refers to any one of the five compilation phases that that - <tt>llvmc</tt> supports. The five phases are: - <a href="#def_preprocessing">preprocessing</a>, - <a href="#def_translation">translation</a>, - <a href="#def_optimization">optimization</a>, - <a href="#def_assembly">assembly</a>, - <a href="#def_linking">linking</a>.</dd> - - <dt><a name="def_sourcelanguage"><b>source language</b></a></dt> - <dd>Any common programming language (e.g. C, C++, Java, Stacker, ML, - FORTRAN). These languages are distinguished from any of the lower level - languages (such as LLVM or native assembly), by the fact that a - <a href="#def_translation">translation</a> <a href="#def_phase">phase</a> - is required before LLVM can be applied.</dd> - - <dt><a name="def_tool"><b>tool</b></a></dt> - <dd>Refers to any program in the LLVM tool set.</dd> - - <dt><a name="def_translation"><b>translation</b></a></dt> - <dd>A compilation <a href="#def_phase">phase</a> in which - <a href="#def_sourcelanguage">source language</a> code is translated into - either LLVM assembly language or LLVM bitcode.</dd> - </dl> </div> -<!-- *********************************************************************** --> -<hr> -<address> <a href="http://jigsaw.w3.org/css-validator/check/referer"><img - src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a><a - href="http://validator.w3.org/check/referer"><img - src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a><a - href="mailto:rspencer@x10sys.com">Reid Spencer</a><br> -<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br> -Last modified: $Date$ -</address> -<!-- vim: sw=2 ---> </body> </html> |