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diff --git a/docs/CompilerDriver.html b/docs/CompilerDriver.html new file mode 100644 index 0000000..253f471 --- /dev/null +++ b/docs/CompilerDriver.html @@ -0,0 +1,823 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> +<html> +<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."> +</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="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_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> + +<!-- _______________________________________________________________________ --> +<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> +</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_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> + +<!-- *********************************************************************** --> +<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> + +<!-- _______________________________________________________________________ --> +<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> + +<!-- _______________________________________________________________________ --> +<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> + +<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> + +<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> + +<!-- _______________________________________________________________________ --> +<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> + +<!-- _______________________________________________________________________ --> +<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> + +<!-- _______________________________________________________________________ --> +<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> + +<!-- _______________________________________________________________________ --> +<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> |