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3<html>
4<head>
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]6 <title>CommandLine 2.0 Library Manual</title>
Misha Brukman7120c832003-11-07 18:11:14 +0000[diff] [blame]7 <link rel="stylesheet" href="llvm.css" type="text/css">
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]8</head>
9<body>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]10
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]11<div class="doc_title">
12 CommandLine 2.0 Library Manual
13</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]14
15<ol>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]16 <li><a href="#introduction">Introduction</a></li>
17
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]18 <li><a href="#quickstart">Quick Start Guide</a>
19 <ol>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]20 <li><a href="#bool">Boolean Arguments</a></li>
21 <li><a href="#alias">Argument Aliases</a></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]22 <li><a href="#onealternative">Selecting an alternative from a
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]23 set of possibilities</a></li>
24 <li><a href="#namedalternatives">Named alternatives</a></li>
25 <li><a href="#list">Parsing a list of options</a></li>
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]26 <li><a href="#bits">Collecting options as a set of flags</a></li>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]27 <li><a href="#description">Adding freeform text to help output</a></li>
28 </ol></li>
29
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]30 <li><a href="#referenceguide">Reference Guide</a>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]31 <ol>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]32 <li><a href="#positional">Positional Arguments</a>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]33 <ul>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]34 <li><a href="#--">Specifying positional options with hyphens</a></li>
Reid Spencerc0f1b212004-08-13 20:19:14 +0000[diff] [blame]35 <li><a href="#getPosition">Determining absolute position with
36 getPosition</a></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]37 <li><a href="#cl::ConsumeAfter">The <tt>cl::ConsumeAfter</tt>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]38 modifier</a></li>
39 </ul></li>
40
41 <li><a href="#storage">Internal vs External Storage</a></li>
42
43 <li><a href="#attributes">Option Attributes</a></li>
44
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]45 <li><a href="#modifiers">Option Modifiers</a>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]46 <ul>
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]47 <li><a href="#hiding">Hiding an option from <tt>--help</tt>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]48 output</a></li>
49 <li><a href="#numoccurrences">Controlling the number of occurrences
50 required and allowed</a></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]51 <li><a href="#valrequired">Controlling whether or not a value must be
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]52 specified</a></li>
53 <li><a href="#formatting">Controlling other formatting options</a></li>
54 <li><a href="#misc">Miscellaneous option modifiers</a></li>
55 </ul></li>
56
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]57 <li><a href="#toplevel">Top-Level Classes and Functions</a>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]58 <ul>
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]59 <li><a href="#cl::ParseCommandLineOptions">The
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]60 <tt>cl::ParseCommandLineOptions</tt> function</a></li>
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]61 <li><a href="#cl::ParseEnvironmentOptions">The
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]62 <tt>cl::ParseEnvironmentOptions</tt> function</a></li>
Chris Lattnerf1be2882007-12-19 19:48:49 +0000[diff] [blame]63 <li><a href="#cl::SetVersionPrinter">The <tt>cl::SetVersionPrinter</tt>
Reid Spencer0075b2f2006-06-05 17:30:16 +0000[diff] [blame]64 function</a></li>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]65 <li><a href="#cl::opt">The <tt>cl::opt</tt> class</a></li>
66 <li><a href="#cl::list">The <tt>cl::list</tt> class</a></li>
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]67 <li><a href="#cl::bits">The <tt>cl::bits</tt> class</a></li>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]68 <li><a href="#cl::alias">The <tt>cl::alias</tt> class</a></li>
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]69 <li><a href="#cl::extrahelp">The <tt>cl::extrahelp</tt> class</a></li>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]70 </ul></li>
71
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]72 <li><a href="#builtinparsers">Builtin parsers</a>
73 <ul>
74 <li><a href="#genericparser">The Generic <tt>parser&lt;t&gt;</tt>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]75 parser</a></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]76 <li><a href="#boolparser">The <tt>parser&lt;bool&gt;</tt>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]77 specialization</a></li>
Dale Johannesen10c5ccc2007-05-22 18:32:34 +0000[diff] [blame]78 <li><a href="#boolOrDefaultparser">The <tt>parser&lt;boolOrDefault&gt;</tt>
79 specialization</a></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]80 <li><a href="#stringparser">The <tt>parser&lt;string&gt;</tt>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]81 specialization</a></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]82 <li><a href="#intparser">The <tt>parser&lt;int&gt;</tt>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]83 specialization</a></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]84 <li><a href="#doubleparser">The <tt>parser&lt;double&gt;</tt> and
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]85 <tt>parser&lt;float&gt;</tt> specializations</a></li>
86 </ul></li>
87 </ol></li>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]88 <li><a href="#extensionguide">Extension Guide</a>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]89 <ol>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]90 <li><a href="#customparser">Writing a custom parser</a></li>
91 <li><a href="#explotingexternal">Exploiting external storage</a></li>
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]92 <li><a href="#dynamicopts">Dynamically adding command line
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]93 options</a></li>
94 </ol></li>
95</ol>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]96
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]97<div class="doc_author">
98 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a></p>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]99</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]100
101<!-- *********************************************************************** -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]102<div class="doc_section">
Misha Brukman403ff612003-11-07 19:42:44 +0000[diff] [blame]103 <a name="introduction">Introduction</a>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]104</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]105<!-- *********************************************************************** -->
106
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]107<div class="doc_text">
108
109<p>This document describes the CommandLine argument processing library. It will
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]110show you how to use it, and what it can do. The CommandLine library uses a
111declarative approach to specifying the command line options that your program
112takes. By default, these options declarations implicitly hold the value parsed
113for the option declared (of course this <a href="#storage">can be
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]114changed</a>).</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]115
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]116<p>Although there are a <b>lot</b> of command line argument parsing libraries
117out there in many different languages, none of them fit well with what I needed.
118By looking at the features and problems of other libraries, I designed the
119CommandLine library to have the following features:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]120
121<ol>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]122<li>Speed: The CommandLine library is very quick and uses little resources. The
123parsing time of the library is directly proportional to the number of arguments
124parsed, not the the number of options recognized. Additionally, command line
Chris Lattner364e6312003-06-21 21:45:56 +0000[diff] [blame]125argument values are captured transparently into user defined global variables,
126which can be accessed like any other variable (and with the same
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]127performance).</li>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]128
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]129<li>Type Safe: As a user of CommandLine, you don't have to worry about
130remembering the type of arguments that you want (is it an int? a string? a
131bool? an enum?) and keep casting it around. Not only does this help prevent
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]132error prone constructs, it also leads to dramatically cleaner source code.</li>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]133
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]134<li>No subclasses required: To use CommandLine, you instantiate variables that
135correspond to the arguments that you would like to capture, you don't subclass a
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]136parser. This means that you don't have to write <b>any</b> boilerplate
137code.</li>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]138
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]139<li>Globally accessible: Libraries can specify command line arguments that are
140automatically enabled in any tool that links to the library. This is possible
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]141because the application doesn't have to keep a list of arguments to pass to
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]142the parser. This also makes supporting <a href="#dynamicopts">dynamically
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]143loaded options</a> trivial.</li>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]144
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]145<li>Cleaner: CommandLine supports enum and other types directly, meaning that
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]146there is less error and more security built into the library. You don't have to
147worry about whether your integral command line argument accidentally got
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]148assigned a value that is not valid for your enum type.</li>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]149
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]150<li>Powerful: The CommandLine library supports many different types of
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]151arguments, from simple <a href="#boolparser">boolean flags</a> to <a
152href="#cl::opt">scalars arguments</a> (<a href="#stringparser">strings</a>, <a
153href="#intparser">integers</a>, <a href="#genericparser">enums</a>, <a
154href="#doubleparser">doubles</a>), to <a href="#cl::list">lists of
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]155arguments</a>. This is possible because CommandLine is...</li>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]156
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]157<li>Extensible: It is very simple to add a new argument type to CommandLine.
158Simply specify the parser that you want to use with the command line option when
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]159you declare it. <a href="#customparser">Custom parsers</a> are no problem.</li>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]160
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]161<li>Labor Saving: The CommandLine library cuts down on the amount of grunt work
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]162that you, the user, have to do. For example, it automatically provides a
163<tt>--help</tt> option that shows the available command line options for your
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]164tool. Additionally, it does most of the basic correctness checking for
165you.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]166
167<li>Capable: The CommandLine library can handle lots of different forms of
168options often found in real programs. For example, <a
169href="#positional">positional</a> arguments, <tt>ls</tt> style <a
170href="#cl::Grouping">grouping</a> options (to allow processing '<tt>ls
171-lad</tt>' naturally), <tt>ld</tt> style <a href="#cl::Prefix">prefix</a>
172options (to parse '<tt>-lmalloc -L/usr/lib</tt>'), and <a
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]173href="#cl::ConsumeAfter">interpreter style options</a>.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]174
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]175</ol>
176
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]177<p>This document will hopefully let you jump in and start using CommandLine in
178your utility quickly and painlessly. Additionally it should be a simple
179reference manual to figure out how stuff works. If it is failing in some area
180(or you want an extension to the library), nag the author, <a
181href="mailto:sabre@nondot.org">Chris Lattner</a>.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]182
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]183</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]184
185<!-- *********************************************************************** -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]186<div class="doc_section">
187 <a name="quickstart">Quick Start Guide</a>
188</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]189<!-- *********************************************************************** -->
190
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]191<div class="doc_text">
192
193<p>This section of the manual runs through a simple CommandLine'ification of a
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]194basic compiler tool. This is intended to show you how to jump into using the
195CommandLine library in your own program, and show you some of the cool things it
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]196can do.</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]197
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]198<p>To start out, you need to include the CommandLine header file into your
199program:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]200
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]201<div class="doc_code"><pre>
Andrew Lenharthb720e2c2005-11-14 19:32:05 +0000[diff] [blame]202 #include "llvm/Support/CommandLine.h"
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]203</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]204
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]205<p>Additionally, you need to add this as the first line of your main
206program:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]207
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]208<div class="doc_code"><pre>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]209int main(int argc, char **argv) {
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]210 <a href="#cl::ParseCommandLineOptions">cl::ParseCommandLineOptions</a>(argc, argv);
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]211 ...
212}
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]213</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]214
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]215<p>... which actually parses the arguments and fills in the variable
216declarations.</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]217
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]218<p>Now that you are ready to support command line arguments, we need to tell the
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]219system which ones we want, and what type of arguments they are. The CommandLine
Chris Lattner364e6312003-06-21 21:45:56 +0000[diff] [blame]220library uses a declarative syntax to model command line arguments with the
221global variable declarations that capture the parsed values. This means that
222for every command line option that you would like to support, there should be a
223global variable declaration to capture the result. For example, in a compiler,
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]224we would like to support the Unix-standard '<tt>-o &lt;filename&gt;</tt>' option
Chris Lattner364e6312003-06-21 21:45:56 +0000[diff] [blame]225to specify where to put the output. With the CommandLine library, this is
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]226represented like this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]227
Misha Brukman374258e2004-05-12 18:42:35 +0000[diff] [blame]228<a name="value_desc_example"></a>
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]229<div class="doc_code"><pre>
Misha Brukman374258e2004-05-12 18:42:35 +0000[diff] [blame]230<a href="#cl::opt">cl::opt</a>&lt;string&gt; OutputFilename("<i>o</i>", <a href="#cl::desc">cl::desc</a>("<i>Specify output filename</i>"), <a href="#cl::value_desc">cl::value_desc</a>("<i>filename</i>"));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]231</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]232
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]233<p>This declares a global variable "<tt>OutputFilename</tt>" that is used to
Chris Lattner364e6312003-06-21 21:45:56 +0000[diff] [blame]234capture the result of the "<tt>o</tt>" argument (first parameter). We specify
235that this is a simple scalar option by using the "<tt><a
236href="#cl::opt">cl::opt</a></tt>" template (as opposed to the <a
237href="#list">"<tt>cl::list</tt> template</a>), and tell the CommandLine library
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]238that the data type that we are parsing is a string.</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]239
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]240<p>The second and third parameters (which are optional) are used to specify what
241to output for the "<tt>--help</tt>" option. In this case, we get a line that
242looks like this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]243
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]244<div class="doc_code"><pre>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]245USAGE: compiler [options]
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]246
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]247OPTIONS:
248 -help - display available options (--help-hidden for more)
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]249 <b>-o &lt;filename&gt; - Specify output filename</b>
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]250</pre></div>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]251
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]252<p>Because we specified that the command line option should parse using the
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]253<tt>string</tt> data type, the variable declared is automatically usable as a
254real string in all contexts that a normal C++ string object may be used. For
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]255example:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]256
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]257<div class="doc_code"><pre>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]258 ...
Chris Lattnera01203e2008-03-30 16:59:21 +0000[diff] [blame^]259 std::ofstream Output(OutputFilename.c_str());
260 if (Output.good()) ...
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]261 ...
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]262</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]263
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]264<p>There are many different options that you can use to customize the command
265line option handling library, but the above example shows the general interface
266to these options. The options can be specified in any order, and are specified
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]267with helper functions like <a href="#cl::desc"><tt>cl::desc(...)</tt></a>, so
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]268there are no positional dependencies to remember. The available options are
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]269discussed in detail in the <a href="#referenceguide">Reference Guide</a>.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]270
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]271<p>Continuing the example, we would like to have our compiler take an input
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]272filename as well as an output filename, but we do not want the input filename to
273be specified with a hyphen (ie, not <tt>-filename.c</tt>). To support this
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]274style of argument, the CommandLine library allows for <a
275href="#positional">positional</a> arguments to be specified for the program.
276These positional arguments are filled with command line parameters that are not
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]277in option form. We use this feature like this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]278
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]279<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]280<a href="#cl::opt">cl::opt</a>&lt;string&gt; InputFilename(<a href="#cl::Positional">cl::Positional</a>, <a href="#cl::desc">cl::desc</a>("<i>&lt;input file&gt;</i>"), <a href="#cl::init">cl::init</a>("<i>-</i>"));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]281</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]282
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]283<p>This declaration indicates that the first positional argument should be
284treated as the input filename. Here we use the <tt><a
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]285href="#cl::init">cl::init</a></tt> option to specify an initial value for the
286command line option, which is used if the option is not specified (if you do not
287specify a <tt><a href="#cl::init">cl::init</a></tt> modifier for an option, then
288the default constructor for the data type is used to initialize the value).
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]289Command line options default to being optional, so if we would like to require
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]290that the user always specify an input filename, we would add the <tt><a
291href="#cl::Required">cl::Required</a></tt> flag, and we could eliminate the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]292<tt><a href="#cl::init">cl::init</a></tt> modifier, like this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]293
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]294<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]295<a href="#cl::opt">cl::opt</a>&lt;string&gt; InputFilename(<a href="#cl::Positional">cl::Positional</a>, <a href="#cl::desc">cl::desc</a>("<i>&lt;input file&gt;</i>"), <b><a href="#cl::Required">cl::Required</a></b>);
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]296</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]297
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]298<p>Again, the CommandLine library does not require the options to be specified
299in any particular order, so the above declaration is equivalent to:</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]300
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]301<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]302<a href="#cl::opt">cl::opt</a>&lt;string&gt; InputFilename(<a href="#cl::Positional">cl::Positional</a>, <a href="#cl::Required">cl::Required</a>, <a href="#cl::desc">cl::desc</a>("<i>&lt;input file&gt;</i>"));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]303</pre></div>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]304
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]305<p>By simply adding the <tt><a href="#cl::Required">cl::Required</a></tt> flag,
306the CommandLine library will automatically issue an error if the argument is not
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]307specified, which shifts all of the command line option verification code out of
308your application into the library. This is just one example of how using flags
309can alter the default behaviour of the library, on a per-option basis. By
310adding one of the declarations above, the <tt>--help</tt> option synopsis is now
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]311extended to:</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]312
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]313<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]314USAGE: compiler [options] <b>&lt;input file&gt;</b>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]315
316OPTIONS:
317 -help - display available options (--help-hidden for more)
318 -o &lt;filename&gt; - Specify output filename
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]319</pre></div>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]320
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]321<p>... indicating that an input filename is expected.</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]322
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]323</div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]324
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]325<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]326<div class="doc_subsection">
327 <a name="bool">Boolean Arguments</a>
328</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]329
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]330<div class="doc_text">
331
332<p>In addition to input and output filenames, we would like the compiler example
333to support three boolean flags: "<tt>-f</tt>" to force overwriting of the output
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]334file, "<tt>--quiet</tt>" to enable quiet mode, and "<tt>-q</tt>" for backwards
335compatibility with some of our users. We can support these by declaring options
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]336of boolean type like this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]337
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]338<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]339<a href="#cl::opt">cl::opt</a>&lt;bool&gt; Force ("<i>f</i>", <a href="#cl::desc">cl::desc</a>("<i>Overwrite output files</i>"));
340<a href="#cl::opt">cl::opt</a>&lt;bool&gt; Quiet ("<i>quiet</i>", <a href="#cl::desc">cl::desc</a>("<i>Don't print informational messages</i>"));
341<a href="#cl::opt">cl::opt</a>&lt;bool&gt; Quiet2("<i>q</i>", <a href="#cl::desc">cl::desc</a>("<i>Don't print informational messages</i>"), <a href="#cl::Hidden">cl::Hidden</a>);
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]342</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]343
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]344<p>This does what you would expect: it declares three boolean variables
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]345("<tt>Force</tt>", "<tt>Quiet</tt>", and "<tt>Quiet2</tt>") to recognize these
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]346options. Note that the "<tt>-q</tt>" option is specified with the "<a
347href="#cl::Hidden"><tt>cl::Hidden</tt></a>" flag. This modifier prevents it
348from being shown by the standard "<tt>--help</tt>" output (note that it is still
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]349shown in the "<tt>--help-hidden</tt>" output).</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]350
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]351<p>The CommandLine library uses a <a href="#builtinparsers">different parser</a>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]352for different data types. For example, in the string case, the argument passed
353to the option is copied literally into the content of the string variable... we
354obviously cannot do that in the boolean case, however, so we must use a smarter
355parser. In the case of the boolean parser, it allows no options (in which case
356it assigns the value of true to the variable), or it allows the values
357"<tt>true</tt>" or "<tt>false</tt>" to be specified, allowing any of the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]358following inputs:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]359
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]360<div class="doc_code"><pre>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]361 compiler -f # No value, 'Force' == true
362 compiler -f=true # Value specified, 'Force' == true
363 compiler -f=TRUE # Value specified, 'Force' == true
364 compiler -f=FALSE # Value specified, 'Force' == false
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]365</pre></div>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]366
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]367<p>... you get the idea. The <a href="#boolparser">bool parser</a> just turns
368the string values into boolean values, and rejects things like '<tt>compiler
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]369-f=foo</tt>'. Similarly, the <a href="#doubleparser">float</a>, <a
370href="#doubleparser">double</a>, and <a href="#intparser">int</a> parsers work
371like you would expect, using the '<tt>strtol</tt>' and '<tt>strtod</tt>' C
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]372library calls to parse the string value into the specified data type.</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]373
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]374<p>With the declarations above, "<tt>compiler --help</tt>" emits this:</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]375
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]376<div class="doc_code"><pre>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]377USAGE: compiler [options] &lt;input file&gt;
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]378
379OPTIONS:
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]380 <b>-f - Overwrite output files</b>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]381 -o - Override output filename
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]382 <b>-quiet - Don't print informational messages</b>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]383 -help - display available options (--help-hidden for more)
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]384</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]385
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]386<p>and "<tt>compiler --help-hidden</tt>" prints this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]387
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]388<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]389USAGE: compiler [options] &lt;input file&gt;
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]390
391OPTIONS:
392 -f - Overwrite output files
393 -o - Override output filename
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]394 <b>-q - Don't print informational messages</b>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]395 -quiet - Don't print informational messages
396 -help - display available options (--help-hidden for more)
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]397</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]398
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]399<p>This brief example has shown you how to use the '<tt><a
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]400href="#cl::opt">cl::opt</a></tt>' class to parse simple scalar command line
401arguments. In addition to simple scalar arguments, the CommandLine library also
402provides primitives to support CommandLine option <a href="#alias">aliases</a>,
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]403and <a href="#list">lists</a> of options.</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]404
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]405</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]406
407<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]408<div class="doc_subsection">
409 <a name="alias">Argument Aliases</a>
410</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]411
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]412<div class="doc_text">
413
414<p>So far, the example works well, except for the fact that we need to check the
415quiet condition like this now:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]416
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]417<div class="doc_code"><pre>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]418...
419 if (!Quiet &amp;&amp; !Quiet2) printInformationalMessage(...);
420...
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]421</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]422
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]423<p>... which is a real pain! Instead of defining two values for the same
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]424condition, we can use the "<tt><a href="#cl::alias">cl::alias</a></tt>" class to make the "<tt>-q</tt>"
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]425option an <b>alias</b> for the "<tt>-quiet</tt>" option, instead of providing
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]426a value itself:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]427
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]428<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]429<a href="#cl::opt">cl::opt</a>&lt;bool&gt; Force ("<i>f</i>", <a href="#cl::desc">cl::desc</a>("<i>Overwrite output files</i>"));
430<a href="#cl::opt">cl::opt</a>&lt;bool&gt; Quiet ("<i>quiet</i>", <a href="#cl::desc">cl::desc</a>("<i>Don't print informational messages</i>"));
431<a href="#cl::alias">cl::alias</a> QuietA("<i>q</i>", <a href="#cl::desc">cl::desc</a>("<i>Alias for -quiet</i>"), <a href="#cl::aliasopt">cl::aliasopt</a>(Quiet));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]432</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]433
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]434<p>The third line (which is the only one we modified from above) defines a
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]435"<tt>-q</tt>" alias that updates the "<tt>Quiet</tt>" variable (as specified by
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]436the <tt><a href="#cl::aliasopt">cl::aliasopt</a></tt> modifier) whenever it is
437specified. Because aliases do not hold state, the only thing the program has to
438query is the <tt>Quiet</tt> variable now. Another nice feature of aliases is
439that they automatically hide themselves from the <tt>-help</tt> output
440(although, again, they are still visible in the <tt>--help-hidden
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]441output</tt>).</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]442
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]443<p>Now the application code can simply use:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]444
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]445<div class="doc_code"><pre>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]446...
447 if (!Quiet) printInformationalMessage(...);
448...
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]449</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]450
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]451<p>... which is much nicer! The "<tt><a href="#cl::alias">cl::alias</a></tt>"
452can be used to specify an alternative name for any variable type, and has many
453uses.</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]454
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]455</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]456
457<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]458<div class="doc_subsection">
459 <a name="onealternative">Selecting an alternative from a set of
460 possibilities</a>
461</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]462
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]463<div class="doc_text">
464
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]465<p>So far we have seen how the CommandLine library handles builtin types like
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]466<tt>std::string</tt>, <tt>bool</tt> and <tt>int</tt>, but how does it handle
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]467things it doesn't know about, like enums or '<tt>int*</tt>'s?</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]468
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]469<p>The answer is that it uses a table-driven generic parser (unless you specify
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]470your own parser, as described in the <a href="#extensionguide">Extension
Reid Spencera39bf3d2004-08-10 16:38:18 +0000[diff] [blame]471Guide</a>). This parser maps literal strings to whatever type is required, and
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]472requires you to tell it what this mapping should be.</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]473
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]474<p>Let's say that we would like to add four optimization levels to our
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]475optimizer, using the standard flags "<tt>-g</tt>", "<tt>-O0</tt>",
476"<tt>-O1</tt>", and "<tt>-O2</tt>". We could easily implement this with boolean
477options like above, but there are several problems with this strategy:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]478
479<ol>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]480<li>A user could specify more than one of the options at a time, for example,
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]481"<tt>compiler -O3 -O2</tt>". The CommandLine library would not be able to
482catch this erroneous input for us.</li>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]483
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]484<li>We would have to test 4 different variables to see which ones are set.</li>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]485
486<li>This doesn't map to the numeric levels that we want... so we cannot easily
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]487see if some level &gt;= "<tt>-O1</tt>" is enabled.</li>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]488
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]489</ol>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]490
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]491<p>To cope with these problems, we can use an enum value, and have the
492CommandLine library fill it in with the appropriate level directly, which is
493used like this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]494
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]495<div class="doc_code"><pre>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]496enum OptLevel {
497 g, O1, O2, O3
498};
499
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]500<a href="#cl::opt">cl::opt</a>&lt;OptLevel&gt; OptimizationLevel(<a href="#cl::desc">cl::desc</a>("<i>Choose optimization level:</i>"),
501 <a href="#cl::values">cl::values</a>(
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]502 clEnumVal(g , "<i>No optimizations, enable debugging</i>"),
503 clEnumVal(O1, "<i>Enable trivial optimizations</i>"),
504 clEnumVal(O2, "<i>Enable default optimizations</i>"),
505 clEnumVal(O3, "<i>Enable expensive optimizations</i>"),
Chris Lattner1fbd76e2004-07-16 00:10:54 +0000[diff] [blame]506 clEnumValEnd));
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]507
508...
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]509 if (OptimizationLevel &gt;= O2) doPartialRedundancyElimination(...);
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]510...
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]511</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]512
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]513<p>This declaration defines a variable "<tt>OptimizationLevel</tt>" of the
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]514"<tt>OptLevel</tt>" enum type. This variable can be assigned any of the values
515that are listed in the declaration (Note that the declaration list must be
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]516terminated with the "<tt>clEnumValEnd</tt>" argument!). The CommandLine
Chris Lattner1fbd76e2004-07-16 00:10:54 +0000[diff] [blame]517library enforces
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]518that the user can only specify one of the options, and it ensure that only valid
519enum values can be specified. The "<tt>clEnumVal</tt>" macros ensure that the
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]520command line arguments matched the enum values. With this option added, our
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]521help output now is:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]522
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]523<div class="doc_code"><pre>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]524USAGE: compiler [options] &lt;input file&gt;
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]525
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]526OPTIONS:
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]527 <b>Choose optimization level:
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]528 -g - No optimizations, enable debugging
529 -O1 - Enable trivial optimizations
530 -O2 - Enable default optimizations
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]531 -O3 - Enable expensive optimizations</b>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]532 -f - Overwrite output files
533 -help - display available options (--help-hidden for more)
534 -o &lt;filename&gt; - Specify output filename
535 -quiet - Don't print informational messages
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]536</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]537
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]538<p>In this case, it is sort of awkward that flag names correspond directly to
539enum names, because we probably don't want a enum definition named "<tt>g</tt>"
540in our program. Because of this, we can alternatively write this example like
541this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]542
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]543<div class="doc_code"><pre>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]544enum OptLevel {
545 Debug, O1, O2, O3
546};
547
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]548<a href="#cl::opt">cl::opt</a>&lt;OptLevel&gt; OptimizationLevel(<a href="#cl::desc">cl::desc</a>("<i>Choose optimization level:</i>"),
549 <a href="#cl::values">cl::values</a>(
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]550 clEnumValN(Debug, "g", "<i>No optimizations, enable debugging</i>"),
551 clEnumVal(O1 , "<i>Enable trivial optimizations</i>"),
552 clEnumVal(O2 , "<i>Enable default optimizations</i>"),
553 clEnumVal(O3 , "<i>Enable expensive optimizations</i>"),
Chris Lattner1fbd76e2004-07-16 00:10:54 +0000[diff] [blame]554 clEnumValEnd));
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]555
556...
557 if (OptimizationLevel == Debug) outputDebugInfo(...);
558...
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]559</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]560
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]561<p>By using the "<tt>clEnumValN</tt>" macro instead of "<tt>clEnumVal</tt>", we
562can directly specify the name that the flag should get. In general a direct
563mapping is nice, but sometimes you can't or don't want to preserve the mapping,
564which is when you would use it.</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]565
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]566</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]567
568<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]569<div class="doc_subsection">
570 <a name="namedalternatives">Named Alternatives</a>
571</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]572
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]573<div class="doc_text">
574
575<p>Another useful argument form is a named alternative style. We shall use this
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]576style in our compiler to specify different debug levels that can be used.
577Instead of each debug level being its own switch, we want to support the
578following options, of which only one can be specified at a time:
579"<tt>--debug-level=none</tt>", "<tt>--debug-level=quick</tt>",
580"<tt>--debug-level=detailed</tt>". To do this, we use the exact same format as
581our optimization level flags, but we also specify an option name. For this
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]582case, the code looks like this:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]583
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]584<div class="doc_code"><pre>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]585enum DebugLev {
586 nodebuginfo, quick, detailed
587};
588
589// Enable Debug Options to be specified on the command line
Chris Lattner3b8f3da2003-06-03 04:40:06 +0000[diff] [blame]590<a href="#cl::opt">cl::opt</a>&lt;DebugLev&gt; DebugLevel("<i>debug_level</i>", <a href="#cl::desc">cl::desc</a>("<i>Set the debugging level:</i>"),
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]591 <a href="#cl::values">cl::values</a>(
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]592 clEnumValN(nodebuginfo, "none", "<i>disable debug information</i>"),
593 clEnumVal(quick, "<i>enable quick debug information</i>"),
594 clEnumVal(detailed, "<i>enable detailed debug information</i>"),
Chris Lattner1fbd76e2004-07-16 00:10:54 +0000[diff] [blame]595 clEnumValEnd));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]596</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]597
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]598<p>This definition defines an enumerated command line variable of type "<tt>enum
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]599DebugLev</tt>", which works exactly the same way as before. The difference here
600is just the interface exposed to the user of your program and the help output by
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]601the "<tt>--help</tt>" option:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]602
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]603<div class="doc_code"><pre>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]604USAGE: compiler [options] &lt;input file&gt;
605
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]606OPTIONS:
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]607 Choose optimization level:
608 -g - No optimizations, enable debugging
609 -O1 - Enable trivial optimizations
610 -O2 - Enable default optimizations
611 -O3 - Enable expensive optimizations
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]612 <b>-debug_level - Set the debugging level:
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]613 =none - disable debug information
614 =quick - enable quick debug information
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]615 =detailed - enable detailed debug information</b>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]616 -f - Overwrite output files
617 -help - display available options (--help-hidden for more)
618 -o &lt;filename&gt; - Specify output filename
619 -quiet - Don't print informational messages
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]620</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]621
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]622<p>Again, the only structural difference between the debug level declaration and
John Criswella9f34ca2004-11-21 14:34:34 +0000[diff] [blame]623the optimization level declaration is that the debug level declaration includes
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]624an option name (<tt>"debug_level"</tt>), which automatically changes how the
625library processes the argument. The CommandLine library supports both forms so
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]626that you can choose the form most appropriate for your application.</p>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]627
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]628</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]629
630<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]631<div class="doc_subsection">
632 <a name="list">Parsing a list of options</a>
633</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]634
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]635<div class="doc_text">
636
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]637<p>Now that we have the standard run-of-the-mill argument types out of the way,
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]638lets get a little wild and crazy. Lets say that we want our optimizer to accept
639a <b>list</b> of optimizations to perform, allowing duplicates. For example, we
640might want to run: "<tt>compiler -dce -constprop -inline -dce -strip</tt>". In
641this case, the order of the arguments and the number of appearances is very
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]642important. This is what the "<tt><a href="#cl::list">cl::list</a></tt>"
643template is for. First, start by defining an enum of the optimizations that you
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]644would like to perform:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]645
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]646<div class="doc_code"><pre>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]647enum Opts {
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]648 // 'inline' is a C++ keyword, so name it 'inlining'
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]649 dce, constprop, inlining, strip
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]650};
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]651</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]652
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]653<p>Then define your "<tt><a href="#cl::list">cl::list</a></tt>" variable:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]654
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]655<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]656<a href="#cl::list">cl::list</a>&lt;Opts&gt; OptimizationList(<a href="#cl::desc">cl::desc</a>("<i>Available Optimizations:</i>"),
657 <a href="#cl::values">cl::values</a>(
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]658 clEnumVal(dce , "<i>Dead Code Elimination</i>"),
Misha Brukman373086d2003-05-20 21:01:22 +0000[diff] [blame]659 clEnumVal(constprop , "<i>Constant Propagation</i>"),
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]660 clEnumValN(inlining, "<i>inline</i>", "<i>Procedure Integration</i>"),
661 clEnumVal(strip , "<i>Strip Symbols</i>"),
Chris Lattner1fbd76e2004-07-16 00:10:54 +0000[diff] [blame]662 clEnumValEnd));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]663</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]664
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]665<p>This defines a variable that is conceptually of the type
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]666"<tt>std::vector&lt;enum Opts&gt;</tt>". Thus, you can access it with standard
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]667vector methods:</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]668
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]669<div class="doc_code"><pre>
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]670 for (unsigned i = 0; i != OptimizationList.size(); ++i)
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]671 switch (OptimizationList[i])
672 ...
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]673</pre></div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]674
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]675<p>... to iterate through the list of options specified.</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]676
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]677<p>Note that the "<tt><a href="#cl::list">cl::list</a></tt>" template is
678completely general and may be used with any data types or other arguments that
679you can use with the "<tt><a href="#cl::opt">cl::opt</a></tt>" template. One
680especially useful way to use a list is to capture all of the positional
681arguments together if there may be more than one specified. In the case of a
682linker, for example, the linker takes several '<tt>.o</tt>' files, and needs to
683capture them into a list. This is naturally specified as:</p>
Chris Lattner03133252002-04-13 18:35:59 +0000[diff] [blame]684
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]685<div class="doc_code"><pre>
Chris Lattner03133252002-04-13 18:35:59 +0000[diff] [blame]686...
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]687<a href="#cl::list">cl::list</a>&lt;std::string&gt; InputFilenames(<a href="#cl::Positional">cl::Positional</a>, <a href="#cl::desc">cl::desc</a>("&lt;Input files&gt;"), <a href="#cl::OneOrMore">cl::OneOrMore</a>);
Chris Lattner03133252002-04-13 18:35:59 +0000[diff] [blame]688...
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]689</pre></div>
Chris Lattner03133252002-04-13 18:35:59 +0000[diff] [blame]690
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]691<p>This variable works just like a "<tt>vector&lt;string&gt;</tt>" object. As
Chris Lattner2e19f3e2002-07-25 19:27:01 +0000[diff] [blame]692such, accessing the list is simple, just like above. In this example, we used
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]693the <tt><a href="#cl::OneOrMore">cl::OneOrMore</a></tt> modifier to inform the
694CommandLine library that it is an error if the user does not specify any
695<tt>.o</tt> files on our command line. Again, this just reduces the amount of
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]696checking we have to do.</p>
Chris Lattner03133252002-04-13 18:35:59 +0000[diff] [blame]697
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]698</div>
Chris Lattner03133252002-04-13 18:35:59 +0000[diff] [blame]699
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]700<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]701<div class="doc_subsection">
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]702 <a name="bits">Collecting options as a set of flags</a>
703</div>
704
705<div class="doc_text">
706
707<p>Instead of collecting sets of options in a list, it is also possible to
Jim Laskeyd6281ce2005-08-26 09:25:54 +0000[diff] [blame]708gather information for enum values in a <b>bit vector</b>. The represention used by
709the <a href="#bits"><tt>cl::bits</tt></a> class is an <tt>unsigned</tt>
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]710integer. An enum value is represented by a 0/1 in the enum's ordinal value bit
711position. 1 indicating that the enum was specified, 0 otherwise. As each
712specified value is parsed, the resulting enum's bit is set in the option's bit
713vector:</p>
714
715<div class="doc_code"><pre>
716 <i>bits</i> |= 1 << (unsigned)<i>enum</i>;
717</pre></div>
718
Jim Laskeya82d08f2005-08-25 23:01:25 +0000[diff] [blame]719<p>Options that are specified multiple times are redundant. Any instances after
720the first are discarded.</p>
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]721
722<p>Reworking the above list example, we could replace <a href="#list">
723<tt>cl::list</tt></a> with <a href="#bits"><tt>cl::bits</tt></a>:</p>
724
725<div class="doc_code"><pre>
726<a href="#cl::bits">cl::bits</a>&lt;Opts&gt; OptimizationBits(<a href="#cl::desc">cl::desc</a>("<i>Available Optimizations:</i>"),
727 <a href="#cl::values">cl::values</a>(
728 clEnumVal(dce , "<i>Dead Code Elimination</i>"),
729 clEnumVal(constprop , "<i>Constant Propagation</i>"),
730 clEnumValN(inlining, "<i>inline</i>", "<i>Procedure Integration</i>"),
731 clEnumVal(strip , "<i>Strip Symbols</i>"),
732 clEnumValEnd));
733</pre></div>
734
735<p>To test to see if <tt>constprop</tt> was specified, we can use the
736<tt>cl:bits::isSet</tt> function:</p>
737
738<div class="doc_code"><pre>
739 if (OptimizationBits.isSet(constprop)) {
740 ...
741 }
742</pre></div>
743
744<p>It's also possible to get the raw bit vector using the
745<tt>cl::bits::getBits</tt> function:</p>
746
747<div class="doc_code"><pre>
Jim Laskeyd6281ce2005-08-26 09:25:54 +0000[diff] [blame]748 unsigned bits = OptimizationBits.getBits();
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]749</pre></div>
750
751<p>Finally, if external storage is used, then the location specified must be of
Jim Laskeyd6281ce2005-08-26 09:25:54 +0000[diff] [blame]752<b>type</b> <tt>unsigned</tt>. In all other ways a <a
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]753href="#bits"><tt>cl::bits</tt></a> option is equivalent to a <a
Jim Laskeyd6281ce2005-08-26 09:25:54 +0000[diff] [blame]754href="#list"> <tt>cl::list</tt></a> option.</p>
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]755
756</div>
757
758
759<!-- ======================================================================= -->
760<div class="doc_subsection">
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]761 <a name="description">Adding freeform text to help output</a>
762</div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]763
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]764<div class="doc_text">
765
766<p>As our program grows and becomes more mature, we may decide to put summary
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]767information about what it does into the help output. The help output is styled
768to look similar to a Unix <tt>man</tt> page, providing concise information about
769a program. Unix <tt>man</tt> pages, however often have a description about what
770the program does. To add this to your CommandLine program, simply pass a third
771argument to the <a
772href="#cl::ParseCommandLineOptions"><tt>cl::ParseCommandLineOptions</tt></a>
773call in main. This additional argument is then printed as the overview
774information for your program, allowing you to include any additional information
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]775that you want. For example:</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]776
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]777<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]778int main(int argc, char **argv) {
779 <a href="#cl::ParseCommandLineOptions">cl::ParseCommandLineOptions</a>(argc, argv, " CommandLine compiler example\n\n"
780 " This program blah blah blah...\n");
781 ...
782}
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]783</pre></div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]784
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]785<p>would yield the help output:</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]786
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]787<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]788<b>OVERVIEW: CommandLine compiler example
789
790 This program blah blah blah...</b>
791
792USAGE: compiler [options] &lt;input file&gt;
793
794OPTIONS:
795 ...
796 -help - display available options (--help-hidden for more)
797 -o &lt;filename&gt; - Specify output filename
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]798</pre></div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]799
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]800</div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]801
802
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]803<!-- *********************************************************************** -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]804<div class="doc_section">
805 <a name="referenceguide">Reference Guide</a>
806</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]807<!-- *********************************************************************** -->
808
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]809<div class="doc_text">
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]810
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]811<p>Now that you know the basics of how to use the CommandLine library, this
812section will give you the detailed information you need to tune how command line
813options work, as well as information on more "advanced" command line option
814processing capabilities.</p>
815
816</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]817
818<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]819<div class="doc_subsection">
820 <a name="positional">Positional Arguments</a>
821</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]822
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]823<div class="doc_text">
824
825<p>Positional arguments are those arguments that are not named, and are not
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]826specified with a hyphen. Positional arguments should be used when an option is
827specified by its position alone. For example, the standard Unix <tt>grep</tt>
828tool takes a regular expression argument, and an optional filename to search
829through (which defaults to standard input if a filename is not specified).
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]830Using the CommandLine library, this would be specified as:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]831
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]832<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]833<a href="#cl::opt">cl::opt</a>&lt;string&gt; Regex (<a href="#cl::Positional">cl::Positional</a>, <a href="#cl::desc">cl::desc</a>("<i>&lt;regular expression&gt;</i>"), <a href="#cl::Required">cl::Required</a>);
834<a href="#cl::opt">cl::opt</a>&lt;string&gt; Filename(<a href="#cl::Positional">cl::Positional</a>, <a href="#cl::desc">cl::desc</a>("<i>&lt;input file&gt;</i>"), <a href="#cl::init">cl::init</a>("<i>-</i>"));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]835</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]836
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]837<p>Given these two option declarations, the <tt>--help</tt> output for our grep
838replacement would look like this:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]839
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]840<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]841USAGE: spiffygrep [options] <b>&lt;regular expression&gt; &lt;input file&gt;</b>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]842
843OPTIONS:
844 -help - display available options (--help-hidden for more)
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]845</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]846
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]847<p>... and the resultant program could be used just like the standard
848<tt>grep</tt> tool.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]849
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]850<p>Positional arguments are sorted by their order of construction. This means
851that command line options will be ordered according to how they are listed in a
Reid Spencerc0f1b212004-08-13 20:19:14 +0000[diff] [blame]852.cpp file, but will not have an ordering defined if the positional arguments
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]853are defined in multiple .cpp files. The fix for this problem is simply to
854define all of your positional arguments in one .cpp file.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]855
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]856</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]857
858
859<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]860<div class="doc_subsubsection">
861 <a name="--">Specifying positional options with hyphens</a>
862</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]863
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]864<div class="doc_text">
865
866<p>Sometimes you may want to specify a value to your positional argument that
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]867starts with a hyphen (for example, searching for '<tt>-foo</tt>' in a file). At
868first, you will have trouble doing this, because it will try to find an argument
869named '<tt>-foo</tt>', and will fail (and single quotes will not save you).
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]870Note that the system <tt>grep</tt> has the same problem:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]871
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]872<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]873 $ spiffygrep '-foo' test.txt
874 Unknown command line argument '-foo'. Try: spiffygrep --help'
875
876 $ grep '-foo' test.txt
877 grep: illegal option -- f
878 grep: illegal option -- o
879 grep: illegal option -- o
880 Usage: grep -hblcnsviw pattern file . . .
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]881</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]882
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]883<p>The solution for this problem is the same for both your tool and the system
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]884version: use the '<tt>--</tt>' marker. When the user specifies '<tt>--</tt>' on
885the command line, it is telling the program that all options after the
886'<tt>--</tt>' should be treated as positional arguments, not options. Thus, we
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]887can use it like this:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]888
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]889<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]890 $ spiffygrep -- -foo test.txt
891 ...output...
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]892</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]893
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]894</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]895
896<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]897<div class="doc_subsubsection">
Reid Spencerc0f1b212004-08-13 20:19:14 +0000[diff] [blame]898 <a name="getPosition">Determining absolute position with getPosition()</a>
899</div>
900<div class="doc_text">
901 <p>Sometimes an option can affect or modify the meaning of another option. For
902 example, consider <tt>gcc</tt>'s <tt>-x LANG</tt> option. This tells
903 <tt>gcc</tt> to ignore the suffix of subsequent positional arguments and force
904 the file to be interpreted as if it contained source code in language
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]905 <tt>LANG</tt>. In order to handle this properly , you need to know the
906 absolute position of each argument, especially those in lists, so their
907 interaction(s) can be applied correctly. This is also useful for options like
908 <tt>-llibname</tt> which is actually a positional argument that starts with
Reid Spencerc0f1b212004-08-13 20:19:14 +0000[diff] [blame]909 a dash.</p>
910 <p>So, generally, the problem is that you have two <tt>cl::list</tt> variables
911 that interact in some way. To ensure the correct interaction, you can use the
912 <tt>cl::list::getPosition(optnum)</tt> method. This method returns the
913 absolute position (as found on the command line) of the <tt>optnum</tt>
914 item in the <tt>cl::list</tt>.</p>
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]915 <p>The idiom for usage is like this:</p>
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]916
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]917 <div class="doc_code"><pre>
Reid Spencerc0f1b212004-08-13 20:19:14 +0000[diff] [blame]918 static cl::list&lt;std::string&gt; Files(cl::Positional, cl::OneOrMore);
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]919 static cl::list&lt;std::string&gt; Libraries("l", cl::ZeroOrMore);
Reid Spencerc0f1b212004-08-13 20:19:14 +0000[diff] [blame]920
921 int main(int argc, char**argv) {
922 // ...
923 std::vector&lt;std::string&gt;::iterator fileIt = Files.begin();
924 std::vector&lt;std::string&gt;::iterator libIt = Libraries.begin();
925 unsigned libPos = 0, filePos = 0;
926 while ( 1 ) {
927 if ( libIt != Libraries.end() )
928 libPos = Libraries.getPosition( libIt - Libraries.begin() );
929 else
930 libPos = 0;
931 if ( fileIt != Files.end() )
932 filePos = Files.getPosition( fileIt - Files.begin() );
933 else
934 filePos = 0;
935
936 if ( filePos != 0 &amp;&amp; (libPos == 0 || filePos &lt; libPos) ) {
937 // Source File Is next
938 ++fileIt;
939 }
940 else if ( libPos != 0 &amp;&amp; (filePos == 0 || libPos &lt; filePos) ) {
941 // Library is next
942 ++libIt;
943 }
944 else
945 break; // we're done with the list
946 }
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]947 }</pre></div>
948
Reid Spencerc0f1b212004-08-13 20:19:14 +0000[diff] [blame]949 <p>Note that, for compatibility reasons, the <tt>cl::opt</tt> also supports an
950 <tt>unsigned getPosition()</tt> option that will provide the absolute position
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]951 of that option. You can apply the same approach as above with a
Reid Spencerc0f1b212004-08-13 20:19:14 +0000[diff] [blame]952 <tt>cl::opt</tt> and a <tt>cl::list</tt> option as you can with two lists.</p>
953</div>
954
955<!-- _______________________________________________________________________ -->
956<div class="doc_subsubsection">
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]957 <a name="cl::ConsumeAfter">The <tt>cl::ConsumeAfter</tt> modifier</a>
958</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]959
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]960<div class="doc_text">
961
962<p>The <tt>cl::ConsumeAfter</tt> <a href="#formatting">formatting option</a> is
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]963used to construct programs that use "interpreter style" option processing. With
964this style of option processing, all arguments specified after the last
965positional argument are treated as special interpreter arguments that are not
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]966interpreted by the command line argument.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]967
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]968<p>As a concrete example, lets say we are developing a replacement for the
969standard Unix Bourne shell (<tt>/bin/sh</tt>). To run <tt>/bin/sh</tt>, first
970you specify options to the shell itself (like <tt>-x</tt> which turns on trace
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]971output), then you specify the name of the script to run, then you specify
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]972arguments to the script. These arguments to the script are parsed by the Bourne
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]973shell command line option processor, but are not interpreted as options to the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]974shell itself. Using the CommandLine library, we would specify this as:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]975
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]976<div class="doc_code"><pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]977<a href="#cl::opt">cl::opt</a>&lt;string&gt; Script(<a href="#cl::Positional">cl::Positional</a>, <a href="#cl::desc">cl::desc</a>("<i>&lt;input script&gt;</i>"), <a href="#cl::init">cl::init</a>("-"));
978<a href="#cl::list">cl::list</a>&lt;string&gt; Argv(<a href="#cl::ConsumeAfter">cl::ConsumeAfter</a>, <a href="#cl::desc">cl::desc</a>("<i>&lt;program arguments&gt;...</i>"));
979<a href="#cl::opt">cl::opt</a>&lt;bool&gt; Trace("<i>x</i>", <a href="#cl::desc">cl::desc</a>("<i>Enable trace output</i>"));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]980</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]981
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]982<p>which automatically provides the help output:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]983
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]984<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]985USAGE: spiffysh [options] <b>&lt;input script&gt; &lt;program arguments&gt;...</b>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]986
987OPTIONS:
988 -help - display available options (--help-hidden for more)
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]989 <b>-x - Enable trace output</b>
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]990</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]991
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]992<p>At runtime, if we run our new shell replacement as `<tt>spiffysh -x test.sh
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]993-a -x -y bar</tt>', the <tt>Trace</tt> variable will be set to true, the
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]994<tt>Script</tt> variable will be set to "<tt>test.sh</tt>", and the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]995<tt>Argv</tt> list will contain <tt>["-a", "-x", "-y", "bar"]</tt>, because they
996were specified after the last positional argument (which is the script
997name).</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]998
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]999<p>There are several limitations to when <tt>cl::ConsumeAfter</tt> options can
1000be specified. For example, only one <tt>cl::ConsumeAfter</tt> can be specified
1001per program, there must be at least one <a href="#positional">positional
Chris Lattnerb68bd762004-05-06 22:03:59 +0000[diff] [blame]1002argument</a> specified, there must not be any <a href="#cl::list">cl::list</a>
1003positional arguments, and the <tt>cl::ConsumeAfter</tt> option should be a <a
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1004href="#cl::list">cl::list</a> option.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1005
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1006</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1007
1008<!-- ======================================================================= -->
Chris Lattnerb68bd762004-05-06 22:03:59 +0000[diff] [blame]1009<div class="doc_subsection">
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1010 <a name="storage">Internal vs External Storage</a>
1011</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1012
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1013<div class="doc_text">
1014
1015<p>By default, all command line options automatically hold the value that they
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1016parse from the command line. This is very convenient in the common case,
1017especially when combined with the ability to define command line options in the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1018files that use them. This is called the internal storage model.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1019
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1020<p>Sometimes, however, it is nice to separate the command line option processing
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1021code from the storage of the value parsed. For example, lets say that we have a
1022'<tt>-debug</tt>' option that we would like to use to enable debug information
1023across the entire body of our program. In this case, the boolean value
1024controlling the debug code should be globally accessable (in a header file, for
1025example) yet the command line option processing code should not be exposed to
1026all of these clients (requiring lots of .cpp files to #include
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1027<tt>CommandLine.h</tt>).</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1028
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1029<p>To do this, set up your .h file with your option, like this for example:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1030
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1031<div class="doc_code">
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1032<pre>
1033<i>// DebugFlag.h - Get access to the '-debug' command line option
1034//
1035
1036// DebugFlag - This boolean is set to true if the '-debug' command line option
1037// is specified. This should probably not be referenced directly, instead, use
1038// the DEBUG macro below.
1039//</i>
1040extern bool DebugFlag;
1041
1042<i>// DEBUG macro - This macro should be used by code to emit debug information.
1043// In the '-debug' option is specified on the command line, and if this is a
1044// debug build, then the code specified as the option to the macro will be
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1045// executed. Otherwise it will not be.</i>
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1046<span class="doc_hilite">#ifdef NDEBUG
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1047#define DEBUG(X)
1048#else
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1049#define DEBUG(X)</span> do { if (DebugFlag) { X; } } while (0)
1050<span class="doc_hilite">#endif</span>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1051</pre>
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1052</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1053
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1054<p>This allows clients to blissfully use the <tt>DEBUG()</tt> macro, or the
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1055<tt>DebugFlag</tt> explicitly if they want to. Now we just need to be able to
1056set the <tt>DebugFlag</tt> boolean when the option is set. To do this, we pass
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1057an additional argument to our command line argument processor, and we specify
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1058where to fill in with the <a href="#cl::location">cl::location</a>
1059attribute:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1060
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1061<div class="doc_code">
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1062<pre>
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1063bool DebugFlag; <i>// the actual value</i>
Chris Lattner76884682003-08-01 21:30:37 +0000[diff] [blame]1064static <a href="#cl::opt">cl::opt</a>&lt;bool, true&gt; <i>// The parser</i>
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1065Debug("<i>debug</i>", <a href="#cl::desc">cl::desc</a>("<i>Enable debug output</i>"), <a href="#cl::Hidden">cl::Hidden</a>, <a href="#cl::location">cl::location</a>(DebugFlag));
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1066</pre>
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1067</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1068
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1069<p>In the above example, we specify "<tt>true</tt>" as the second argument to
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1070the <tt><a href="#cl::opt">cl::opt</a></tt> template, indicating that the
1071template should not maintain a copy of the value itself. In addition to this,
1072we specify the <tt><a href="#cl::location">cl::location</a></tt> attribute, so
1073that <tt>DebugFlag</tt> is automatically set.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1074
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1075</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1076
1077<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1078<div class="doc_subsection">
1079 <a name="attributes">Option Attributes</a>
1080</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1081
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1082<div class="doc_text">
1083
1084<p>This section describes the basic attributes that you can specify on
1085options.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1086
1087<ul>
1088
1089<li>The option name attribute (which is required for all options, except <a
1090href="#positional">positional options</a>) specifies what the option name is.
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1091This option is specified in simple double quotes:
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1092
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1093<pre>
1094<a href="#cl::opt">cl::opt</a>&lt;<b>bool</b>&gt; Quiet("<i>quiet</i>");
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1095</pre>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1096
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1097</li>
1098
1099<li><a name="cl::desc">The <b><tt>cl::desc</tt></b></a> attribute specifies a
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1100description for the option to be shown in the <tt>--help</tt> output for the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1101program.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1102
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1103<li><a name="cl::value_desc">The <b><tt>cl::value_desc</tt></b></a> attribute
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1104specifies a string that can be used to fine tune the <tt>--help</tt> output for
1105a command line option. Look <a href="#value_desc_example">here</a> for an
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1106example.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1107
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1108<li><a name="cl::init">The <b><tt>cl::init</tt></b></a> attribute specifies an
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1109inital value for a <a href="#cl::opt">scalar</a> option. If this attribute is
1110not specified then the command line option value defaults to the value created
Brian Gaeke8b89b2b2003-08-19 22:56:22 +0000[diff] [blame]1111by the default constructor for the type. <b>Warning</b>: If you specify both
1112<b><tt>cl::init</tt></b> and <b><tt>cl::location</tt></b> for an option,
1113you must specify <b><tt>cl::location</tt></b> first, so that when the
1114command-line parser sees <b><tt>cl::init</tt></b>, it knows where to put the
1115initial value. (You will get an error at runtime if you don't put them in
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1116the right order.)</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1117
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1118<li><a name="cl::location">The <b><tt>cl::location</tt></b></a> attribute where to
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1119store the value for a parsed command line option if using external storage. See
1120the section on <a href="#storage">Internal vs External Storage</a> for more
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1121information.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1122
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1123<li><a name="cl::aliasopt">The <b><tt>cl::aliasopt</tt></b></a> attribute
Misha Brukmanb139a7d2005-02-09 22:49:05 +0000[diff] [blame]1124specifies which option a <tt><a href="#cl::alias">cl::alias</a></tt> option is
1125an alias for.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1126
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1127<li><a name="cl::values">The <b><tt>cl::values</tt></b></a> attribute specifies
1128the string-to-value mapping to be used by the generic parser. It takes a
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]1129<b>clEnumValEnd terminated</b> list of (option, value, description) triplets
Chris Lattner1fbd76e2004-07-16 00:10:54 +0000[diff] [blame]1130that
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1131specify the option name, the value mapped to, and the description shown in the
1132<tt>--help</tt> for the tool. Because the generic parser is used most
1133frequently with enum values, two macros are often useful:
1134
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1135<ol>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1136
1137<li><a name="clEnumVal">The <b><tt>clEnumVal</tt></b></a> macro is used as a
1138nice simple way to specify a triplet for an enum. This macro automatically
1139makes the option name be the same as the enum name. The first option to the
1140macro is the enum, the second is the description for the command line
1141option.</li>
1142
1143<li><a name="clEnumValN">The <b><tt>clEnumValN</tt></b></a> macro is used to
1144specify macro options where the option name doesn't equal the enum name. For
1145this macro, the first argument is the enum value, the second is the flag name,
1146and the second is the description.</li>
1147
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1148</ol>
1149
1150You will get a compile time error if you try to use cl::values with a parser
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1151that does not support it.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1152
1153</ul>
1154
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1155</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1156
1157<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1158<div class="doc_subsection">
1159 <a name="modifiers">Option Modifiers</a>
1160</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1161
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1162<div class="doc_text">
1163
1164<p>Option modifiers are the flags and expressions that you pass into the
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1165constructors for <tt><a href="#cl::opt">cl::opt</a></tt> and <tt><a
1166href="#cl::list">cl::list</a></tt>. These modifiers give you the ability to
1167tweak how options are parsed and how <tt>--help</tt> output is generated to fit
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1168your application well.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1169
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1170<p>These options fall into five main catagories:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1171
1172<ol>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1173<li><a href="#hiding">Hiding an option from <tt>--help</tt> output</a></li>
1174<li><a href="#numoccurrences">Controlling the number of occurrences
1175 required and allowed</a></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1176<li><a href="#valrequired">Controlling whether or not a value must be
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1177 specified</a></li>
1178<li><a href="#formatting">Controlling other formatting options</a></li>
1179<li><a href="#misc">Miscellaneous option modifiers</a></li>
1180</ol>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1181
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1182<p>It is not possible to specify two options from the same catagory (you'll get
1183a runtime error) to a single option, except for options in the miscellaneous
Chris Lattner7333cc12003-05-22 20:36:06 +0000[diff] [blame]1184catagory. The CommandLine library specifies defaults for all of these settings
1185that are the most useful in practice and the most common, which mean that you
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1186usually shouldn't have to worry about these.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1187
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1188</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1189
1190<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1191<div class="doc_subsubsection">
1192 <a name="hiding">Hiding an option from <tt>--help</tt> output</a>
1193</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1194
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1195<div class="doc_text">
1196
1197<p>The <tt>cl::NotHidden</tt>, <tt>cl::Hidden</tt>, and
1198<tt>cl::ReallyHidden</tt> modifiers are used to control whether or not an option
1199appears in the <tt>--help</tt> and <tt>--help-hidden</tt> output for the
1200compiled program:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1201
1202<ul>
1203
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1204<li><a name="cl::NotHidden">The <b><tt>cl::NotHidden</tt></b></a> modifier
1205(which is the default for <tt><a href="#cl::opt">cl::opt</a></tt> and <tt><a
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1206href="#cl::list">cl::list</a></tt> options) indicates the option is to appear
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1207in both help listings.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1208
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1209<li><a name="cl::Hidden">The <b><tt>cl::Hidden</tt></b></a> modifier (which is the
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1210default for <tt><a href="#cl::alias">cl::alias</a></tt> options) indicates that
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1211the option should not appear in the <tt>--help</tt> output, but should appear in
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1212the <tt>--help-hidden</tt> output.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1213
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1214<li><a name="cl::ReallyHidden">The <b><tt>cl::ReallyHidden</tt></b></a> modifier
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1215indicates that the option should not appear in any help output.</li>
1216
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1217</ul>
1218
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1219</div>
1220
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1221<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1222<div class="doc_subsubsection">
1223 <a name="numoccurrences">Controlling the number of occurrences required and
1224 allowed</a>
1225</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1226
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1227<div class="doc_text">
1228
1229<p>This group of options is used to control how many time an option is allowed
1230(or required) to be specified on the command line of your program. Specifying a
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1231value for this setting allows the CommandLine library to do error checking for
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1232you.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1233
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1234<p>The allowed values for this option group are:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1235
1236<ul>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1237
1238<li><a name="cl::Optional">The <b><tt>cl::Optional</tt></b></a> modifier (which
1239is the default for the <tt><a href="#cl::opt">cl::opt</a></tt> and <tt><a
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1240href="#cl::alias">cl::alias</a></tt> classes) indicates that your program will
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1241allow either zero or one occurrence of the option to be specified.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1242
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1243<li><a name="cl::ZeroOrMore">The <b><tt>cl::ZeroOrMore</tt></b></a> modifier
1244(which is the default for the <tt><a href="#cl::list">cl::list</a></tt> class)
1245indicates that your program will allow the option to be specified zero or more
1246times.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1247
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1248<li><a name="cl::Required">The <b><tt>cl::Required</tt></b></a> modifier
1249indicates that the specified option must be specified exactly one time.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1250
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1251<li><a name="cl::OneOrMore">The <b><tt>cl::OneOrMore</tt></b></a> modifier
1252indicates that the option must be specified at least one time.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1253
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1254<li>The <b><tt>cl::ConsumeAfter</tt></b> modifier is described in the <a
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1255href="#positional">Positional arguments section</a>.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1256
1257</ul>
1258
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1259<p>If an option is not specified, then the value of the option is equal to the
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1260value specified by the <tt><a href="#cl::init">cl::init</a></tt> attribute. If
1261the <tt><a href="#cl::init">cl::init</a></tt> attribute is not specified, the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1262option value is initialized with the default constructor for the data type.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1263
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1264<p>If an option is specified multiple times for an option of the <tt><a
1265href="#cl::opt">cl::opt</a></tt> class, only the last value will be
1266retained.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1267
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1268</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1269
1270<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1271<div class="doc_subsubsection">
1272 <a name="valrequired">Controlling whether or not a value must be specified</a>
1273</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1274
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1275<div class="doc_text">
1276
1277<p>This group of options is used to control whether or not the option allows a
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1278value to be present. In the case of the CommandLine library, a value is either
1279specified with an equal sign (e.g. '<tt>-index-depth=17</tt>') or as a trailing
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1280string (e.g. '<tt>-o a.out</tt>').</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1281
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1282<p>The allowed values for this option group are:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1283
1284<ul>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1285
1286<li><a name="cl::ValueOptional">The <b><tt>cl::ValueOptional</tt></b></a> modifier
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1287(which is the default for <tt>bool</tt> typed options) specifies that it is
1288acceptable to have a value, or not. A boolean argument can be enabled just by
1289appearing on the command line, or it can have an explicit '<tt>-foo=true</tt>'.
1290If an option is specified with this mode, it is illegal for the value to be
1291provided without the equal sign. Therefore '<tt>-foo true</tt>' is illegal. To
1292get this behavior, you must use the <a
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1293href="#cl::ValueRequired">cl::ValueRequired</a> modifier.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1294
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1295<li><a name="cl::ValueRequired">The <b><tt>cl::ValueRequired</tt></b></a> modifier
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1296(which is the default for all other types except for <a
1297href="#onealternative">unnamed alternatives using the generic parser</a>)
1298specifies that a value must be provided. This mode informs the command line
1299library that if an option is not provides with an equal sign, that the next
1300argument provided must be the value. This allows things like '<tt>-o
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1301a.out</tt>' to work.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1302
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1303<li><a name="cl::ValueDisallowed">The <b><tt>cl::ValueDisallowed</tt></b></a>
1304modifier (which is the default for <a href="#onealternative">unnamed
1305alternatives using the generic parser</a>) indicates that it is a runtime error
1306for the user to specify a value. This can be provided to disallow users from
1307providing options to boolean options (like '<tt>-foo=true</tt>').</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1308
1309</ul>
1310
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1311<p>In general, the default values for this option group work just like you would
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1312want them to. As mentioned above, you can specify the <a
1313href="#cl::ValueDisallowed">cl::ValueDisallowed</a> modifier to a boolean
1314argument to restrict your command line parser. These options are mostly useful
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1315when <a href="#extensionguide">extending the library</a>.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1316
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1317</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1318
1319<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1320<div class="doc_subsubsection">
1321 <a name="formatting">Controlling other formatting options</a>
1322</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1323
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1324<div class="doc_text">
1325
1326<p>The formatting option group is used to specify that the command line option
1327has special abilities and is otherwise different from other command line
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1328arguments. As usual, you can only specify one of these arguments at most.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1329
1330<ul>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1331
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1332<li><a name="cl::NormalFormatting">The <b><tt>cl::NormalFormatting</tt></b></a>
1333modifier (which is the default all options) specifies that this option is
1334"normal".</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1335
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1336<li><a name="cl::Positional">The <b><tt>cl::Positional</tt></b></a> modifier
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1337specifies that this is a positional argument that does not have a command line
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1338option associated with it. See the <a href="#positional">Positional
1339Arguments</a> section for more information.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1340
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1341<li>The <b><a href="#cl::ConsumeAfter"><tt>cl::ConsumeAfter</tt></a></b> modifier
1342specifies that this option is used to capture "interpreter style" arguments. See <a href="#cl::ConsumeAfter">this section for more information</a>.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1343
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1344<li><a name="cl::Prefix">The <b><tt>cl::Prefix</tt></b></a> modifier specifies
Reid Spencer80bb6932004-11-24 06:13:42 +0000[diff] [blame]1345that this option prefixes its value. With 'Prefix' options, the equal sign does
1346not separate the value from the option name specified. Instead, the value is
1347everything after the prefix, including any equal sign if present. This is useful
1348for processing odd arguments like <tt>-lmalloc</tt> and <tt>-L/usr/lib</tt> in a
Misha Brukman3f2fa8d2005-05-10 22:05:27 +0000[diff] [blame]1349linker tool or <tt>-DNAME=value</tt> in a compiler tool. Here, the
Reid Spencer80bb6932004-11-24 06:13:42 +0000[diff] [blame]1350'<tt>l</tt>', '<tt>D</tt>' and '<tt>L</tt>' options are normal string (or list)
Misha Brukman3f2fa8d2005-05-10 22:05:27 +0000[diff] [blame]1351options, that have the <b><tt><a href="#cl::Prefix">cl::Prefix</a></tt></b>
1352modifier added to allow the CommandLine library to recognize them. Note that
1353<b><tt><a href="#cl::Prefix">cl::Prefix</a></tt></b> options must not have the
1354<b><tt><a href="#cl::ValueDisallowed">cl::ValueDisallowed</a></tt></b> modifier
1355specified.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1356
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1357<li><a name="cl::Grouping">The <b><tt>cl::Grouping</tt></b></a> modifier is used
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1358to implement Unix-style tools (like <tt>ls</tt>) that have lots of single letter
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1359arguments, but only require a single dash. For example, the '<tt>ls -labF</tt>'
1360command actually enables four different options, all of which are single
Misha Brukman3f2fa8d2005-05-10 22:05:27 +0000[diff] [blame]1361letters. Note that <b><tt><a href="#cl::Grouping">cl::Grouping</a></tt></b>
1362options cannot have values.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1363
1364</ul>
1365
Misha Brukman3f2fa8d2005-05-10 22:05:27 +0000[diff] [blame]1366<p>The CommandLine library does not restrict how you use the <b><tt><a
1367href="#cl::Prefix">cl::Prefix</a></tt></b> or <b><tt><a
1368href="#cl::Grouping">cl::Grouping</a></tt></b> modifiers, but it is possible to
1369specify ambiguous argument settings. Thus, it is possible to have multiple
1370letter options that are prefix or grouping options, and they will still work as
1371designed.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1372
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1373<p>To do this, the CommandLine library uses a greedy algorithm to parse the
1374input option into (potentially multiple) prefix and grouping options. The
1375strategy basically looks like this:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1376
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1377<div class="doc_code"><tt>parse(string OrigInput) {</tt>
Misha Brukman374258e2004-05-12 18:42:35 +0000[diff] [blame]1378
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1379<ol>
1380<li><tt>string input = OrigInput;</tt>
1381<li><tt>if (isOption(input)) return getOption(input).parse();</tt>&nbsp;&nbsp;&nbsp;&nbsp;<i>// Normal option</i>
1382<li><tt>while (!isOption(input) &amp;&amp; !input.empty()) input.pop_back();</tt>&nbsp;&nbsp;&nbsp;&nbsp;<i>// Remove the last letter</i>
1383<li><tt>if (input.empty()) return error();</tt>&nbsp;&nbsp;&nbsp;&nbsp;<i>// No matching option</i>
1384<li><tt>if (getOption(input).isPrefix())<br>
1385&nbsp;&nbsp;return getOption(input).parse(input);</tt>
1386<li><tt>while (!input.empty()) {&nbsp;&nbsp;&nbsp;&nbsp;<i>// Must be grouping options</i><br>
1387&nbsp;&nbsp;getOption(input).parse();<br>
1388&nbsp;&nbsp;OrigInput.erase(OrigInput.begin(), OrigInput.begin()+input.length());<br>
1389&nbsp;&nbsp;input = OrigInput;<br>
1390&nbsp;&nbsp;while (!isOption(input) &amp;&amp; !input.empty()) input.pop_back();<br>
1391}</tt>
Misha Brukman374258e2004-05-12 18:42:35 +0000[diff] [blame]1392<li><tt>if (!OrigInput.empty()) error();</tt></li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1393</ol>
Misha Brukman374258e2004-05-12 18:42:35 +0000[diff] [blame]1394
1395<p><tt>}</tt></p>
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1396</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1397
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1398</div>
Chris Lattner7333cc12003-05-22 20:36:06 +0000[diff] [blame]1399
1400<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1401<div class="doc_subsubsection">
1402 <a name="misc">Miscellaneous option modifiers</a>
1403</div>
Chris Lattner7333cc12003-05-22 20:36:06 +0000[diff] [blame]1404
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1405<div class="doc_text">
1406
1407<p>The miscellaneous option modifiers are the only flags where you can specify
1408more than one flag from the set: they are not mutually exclusive. These flags
1409specify boolean properties that modify the option.</p>
Chris Lattner7333cc12003-05-22 20:36:06 +0000[diff] [blame]1410
1411<ul>
1412
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1413<li><a name="cl::CommaSeparated">The <b><tt>cl::CommaSeparated</tt></b></a> modifier
Chris Lattner7333cc12003-05-22 20:36:06 +0000[diff] [blame]1414indicates that any commas specified for an option's value should be used to
1415split the value up into multiple values for the option. For example, these two
1416options are equivalent when <tt>cl::CommaSeparated</tt> is specified:
1417"<tt>-foo=a -foo=b -foo=c</tt>" and "<tt>-foo=a,b,c</tt>". This option only
1418makes sense to be used in a case where the option is allowed to accept one or
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1419more values (i.e. it is a <a href="#cl::list">cl::list</a> option).</li>
1420
Chris Lattnerb68bd762004-05-06 22:03:59 +0000[diff] [blame]1421<li><a name="cl::PositionalEatsArgs">The
1422<b><tt>cl::PositionalEatsArgs</tt></b></a> modifier (which only applies to
1423positional arguments, and only makes sense for lists) indicates that positional
1424argument should consume any strings after it (including strings that start with
1425a "-") up until another recognized positional argument. For example, if you
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1426have two "eating" positional arguments, "<tt>pos1</tt>" and "<tt>pos2</tt>", the
Chris Lattnerb68bd762004-05-06 22:03:59 +0000[diff] [blame]1427string "<tt>-pos1 -foo -bar baz -pos2 -bork</tt>" would cause the "<tt>-foo -bar
1428-baz</tt>" strings to be applied to the "<tt>-pos1</tt>" option and the
1429"<tt>-bork</tt>" string to be applied to the "<tt>-pos2</tt>" option.</li>
1430
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]1431<li><a name="cl::Sink">The <b><tt>cl::Sink</tt></b></a> modifier is
1432used to handle unknown options. If there is at least one option with
1433<b><tt>cl::Sink</tt></b></a> modifier specified, the parser passes
1434unrecognized option strings to it as values instead of signaling an
1435error. As with <b><tt>cl::CommaSeparated</tt></b></a>, this modifier
1436only makes sense with a <a href="#cl::list">cl::list</a> option.</li>
1437
1438
Chris Lattner7333cc12003-05-22 20:36:06 +0000[diff] [blame]1439</ul>
1440
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]1441<p>So far, these are the only three miscellaneous option modifiers.</p>
Chris Lattner7333cc12003-05-22 20:36:06 +0000[diff] [blame]1442
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1443</div>
Chris Lattner7333cc12003-05-22 20:36:06 +0000[diff] [blame]1444
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1445<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1446<div class="doc_subsection">
1447 <a name="toplevel">Top-Level Classes and Functions</a>
1448</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1449
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1450<div class="doc_text">
1451
1452<p>Despite all of the built-in flexibility, the CommandLine option library
1453really only consists of one function (<a
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1454href="#cl::ParseCommandLineOptions"><tt>cl::ParseCommandLineOptions</tt></a>)
1455and three main classes: <a href="#cl::opt"><tt>cl::opt</tt></a>, <a
1456href="#cl::list"><tt>cl::list</tt></a>, and <a
1457href="#cl::alias"><tt>cl::alias</tt></a>. This section describes these three
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1458classes in detail.</p>
1459
1460</div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1461
1462<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1463<div class="doc_subsubsection">
1464 <a name="cl::ParseCommandLineOptions">The <tt>cl::ParseCommandLineOptions</tt>
1465 function</a>
1466</div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1467
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1468<div class="doc_text">
1469
1470<p>The <tt>cl::ParseCommandLineOptions</tt> function is designed to be called
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1471directly from <tt>main</tt>, and is used to fill in the values of all of the
1472command line option variables once <tt>argc</tt> and <tt>argv</tt> are
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1473available.</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1474
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1475<p>The <tt>cl::ParseCommandLineOptions</tt> function requires two parameters
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1476(<tt>argc</tt> and <tt>argv</tt>), but may also take an optional third parameter
1477which holds <a href="#description">additional extra text</a> to emit when the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1478<tt>--help</tt> option is invoked.</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1479
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1480</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1481
1482<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1483<div class="doc_subsubsection">
1484 <a name="cl::ParseEnvironmentOptions">The <tt>cl::ParseEnvironmentOptions</tt>
1485 function</a>
1486</div>
Brian Gaekef2ea9e02003-08-19 23:11:43 +0000[diff] [blame]1487
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1488<div class="doc_text">
Brian Gaekef2ea9e02003-08-19 23:11:43 +0000[diff] [blame]1489
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1490<p>The <tt>cl::ParseEnvironmentOptions</tt> function has mostly the same effects
1491as <a
1492href="#cl::ParseCommandLineOptions"><tt>cl::ParseCommandLineOptions</tt></a>,
1493except that it is designed to take values for options from an environment
1494variable, for those cases in which reading the command line is not convenient or
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1495desired. It fills in the values of all the command line option variables just
1496like <a
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1497href="#cl::ParseCommandLineOptions"><tt>cl::ParseCommandLineOptions</tt></a>
1498does.</p>
1499
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1500<p>It takes three parameters: the name of the program (since <tt>argv</tt> may
1501not be available, it can't just look in <tt>argv[0]</tt>), the name of the
1502environment variable to examine, and the optional
Brian Gaekef2ea9e02003-08-19 23:11:43 +0000[diff] [blame]1503<a href="#description">additional extra text</a> to emit when the
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1504<tt>--help</tt> option is invoked.</p>
Brian Gaekef2ea9e02003-08-19 23:11:43 +0000[diff] [blame]1505
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1506<p><tt>cl::ParseEnvironmentOptions</tt> will break the environment
Brian Gaekef2ea9e02003-08-19 23:11:43 +0000[diff] [blame]1507variable's value up into words and then process them using
1508<a href="#cl::ParseCommandLineOptions"><tt>cl::ParseCommandLineOptions</tt></a>.
1509<b>Note:</b> Currently <tt>cl::ParseEnvironmentOptions</tt> does not support
1510quoting, so an environment variable containing <tt>-option "foo bar"</tt> will
1511be parsed as three words, <tt>-option</tt>, <tt>"foo</tt>, and <tt>bar"</tt>,
1512which is different from what you would get from the shell with the same
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1513input.</p>
1514
1515</div>
Brian Gaekef2ea9e02003-08-19 23:11:43 +0000[diff] [blame]1516
1517<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1518<div class="doc_subsubsection">
Reid Spencer0075b2f2006-06-05 17:30:16 +0000[diff] [blame]1519 <a name="cl::SetVersionPrinter">The <tt>cl::SetVersionPrinter</tt>
1520 function</a>
1521</div>
1522
1523<div class="doc_text">
1524
1525<p>The <tt>cl::SetVersionPrinter</tt> function is designed to be called
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1526directly from <tt>main</tt> and <i>before</i>
Reid Spencer0075b2f2006-06-05 17:30:16 +0000[diff] [blame]1527<tt>cl::ParseCommandLineOptions</tt>. Its use is optional. It simply arranges
1528for a function to be called in response to the <tt>--version</tt> option instead
1529of having the <tt>CommandLine</tt> library print out the usual version string
1530for LLVM. This is useful for programs that are not part of LLVM but wish to use
1531the <tt>CommandLine</tt> facilities. Such programs should just define a small
1532function that takes no arguments and returns <tt>void</tt> and that prints out
1533whatever version information is appropriate for the program. Pass the address
1534of that function to <tt>cl::SetVersionPrinter</tt> to arrange for it to be
1535called when the <tt>--version</tt> option is given by the user.</p>
1536
1537</div>
1538<!-- _______________________________________________________________________ -->
1539<div class="doc_subsubsection">
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1540 <a name="cl::opt">The <tt>cl::opt</tt> class</a>
1541</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1542
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1543<div class="doc_text">
1544
1545<p>The <tt>cl::opt</tt> class is the class used to represent scalar command line
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1546options, and is the one used most of the time. It is a templated class which
1547can take up to three arguments (all except for the first have default values
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1548though):</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1549
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1550<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1551<b>namespace</b> cl {
1552 <b>template</b> &lt;<b>class</b> DataType, <b>bool</b> ExternalStorage = <b>false</b>,
1553 <b>class</b> ParserClass = parser&lt;DataType&gt; &gt;
1554 <b>class</b> opt;
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1555}
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1556</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1557
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1558<p>The first template argument specifies what underlying data type the command
1559line argument is, and is used to select a default parser implementation. The
1560second template argument is used to specify whether the option should contain
1561the storage for the option (the default) or whether external storage should be
1562used to contain the value parsed for the option (see <a href="#storage">Internal
1563vs External Storage</a> for more information).</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1564
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1565<p>The third template argument specifies which parser to use. The default value
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1566selects an instantiation of the <tt>parser</tt> class based on the underlying
1567data type of the option. In general, this default works well for most
1568applications, so this option is only used when using a <a
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1569href="#customparser">custom parser</a>.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1570
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1571</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1572
1573<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1574<div class="doc_subsubsection">
1575 <a name="cl::list">The <tt>cl::list</tt> class</a>
1576</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1577
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1578<div class="doc_text">
1579
1580<p>The <tt>cl::list</tt> class is the class used to represent a list of command
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1581line options. It too is a templated class which can take up to three
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1582arguments:</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1583
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1584<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1585<b>namespace</b> cl {
1586 <b>template</b> &lt;<b>class</b> DataType, <b>class</b> Storage = <b>bool</b>,
1587 <b>class</b> ParserClass = parser&lt;DataType&gt; &gt;
1588 <b>class</b> list;
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1589}
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1590</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1591
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1592<p>This class works the exact same as the <a
1593href="#cl::opt"><tt>cl::opt</tt></a> class, except that the second argument is
1594the <b>type</b> of the external storage, not a boolean value. For this class,
1595the marker type '<tt>bool</tt>' is used to indicate that internal storage should
1596be used.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1597
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1598</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1599
1600<!-- _______________________________________________________________________ -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1601<div class="doc_subsubsection">
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]1602 <a name="cl::bits">The <tt>cl::bits</tt> class</a>
1603</div>
1604
1605<div class="doc_text">
1606
1607<p>The <tt>cl::bits</tt> class is the class used to represent a list of command
1608line options in the form of a bit vector. It is also a templated class which
1609can take up to three arguments:</p>
1610
1611<div class="doc_code"><pre>
1612<b>namespace</b> cl {
1613 <b>template</b> &lt;<b>class</b> DataType, <b>class</b> Storage = <b>bool</b>,
1614 <b>class</b> ParserClass = parser&lt;DataType&gt; &gt;
1615 <b>class</b> bits;
1616}
1617</pre></div>
1618
1619<p>This class works the exact same as the <a
1620href="#cl::opt"><tt>cl::lists</tt></a> class, except that the second argument
Jim Laskeyd6281ce2005-08-26 09:25:54 +0000[diff] [blame]1621must be of <b>type</b> <tt>unsigned</tt> if external storage is used.</p>
Jim Laskey295810d2005-08-25 22:52:43 +0000[diff] [blame]1622
1623</div>
1624
1625<!-- _______________________________________________________________________ -->
1626<div class="doc_subsubsection">
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1627 <a name="cl::alias">The <tt>cl::alias</tt> class</a>
1628</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1629
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1630<div class="doc_text">
1631
1632<p>The <tt>cl::alias</tt> class is a nontemplated class that is used to form
1633aliases for other arguments.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1634
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1635<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1636<b>namespace</b> cl {
1637 <b>class</b> alias;
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1638}
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1639</pre></div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1640
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1641<p>The <a href="#cl::aliasopt"><tt>cl::aliasopt</tt></a> attribute should be
1642used to specify which option this is an alias for. Alias arguments default to
1643being <a href="#cl::Hidden">Hidden</a>, and use the aliased options parser to do
1644the conversion from string to data.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1645
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1646</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1647
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]1648<!-- _______________________________________________________________________ -->
1649<div class="doc_subsubsection">
1650 <a name="cl::extrahelp">The <tt>cl::extrahelp</tt> class</a>
1651</div>
1652
1653<div class="doc_text">
1654
1655<p>The <tt>cl::extrahelp</tt> class is a nontemplated class that allows extra
1656help text to be printed out for the <tt>--help</tt> option.</p>
1657
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1658<div class="doc_code"><pre>
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]1659<b>namespace</b> cl {
1660 <b>struct</b> extrahelp;
1661}
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1662</pre></div>
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]1663
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]1664<p>To use the extrahelp, simply construct one with a <tt>const char*</tt>
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]1665parameter to the constructor. The text passed to the constructor will be printed
1666at the bottom of the help message, verbatim. Note that multiple
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1667<tt>cl::extrahelp</tt> <b>can</b> be used, but this practice is discouraged. If
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]1668your tool needs to print additional help information, put all that help into a
1669single <tt>cl::extrahelp</tt> instance.</p>
1670<p>For example:</p>
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1671<div class="doc_code"><pre>
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]1672 cl::extrahelp("\nADDITIONAL HELP:\n\n This is the extra help\n");
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1673</pre></div>
Reid Spencer5e554702004-11-16 06:11:52 +0000[diff] [blame]1674</div>
1675
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1676<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1677<div class="doc_subsection">
1678 <a name="builtinparsers">Builtin parsers</a>
1679</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1680
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1681<div class="doc_text">
1682
1683<p>Parsers control how the string value taken from the command line is
1684translated into a typed value, suitable for use in a C++ program. By default,
1685the CommandLine library uses an instance of <tt>parser&lt;type&gt;</tt> if the
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1686command line option specifies that it uses values of type '<tt>type</tt>'.
1687Because of this, custom option processing is specified with specializations of
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1688the '<tt>parser</tt>' class.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1689
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1690<p>The CommandLine library provides the following builtin parser
1691specializations, which are sufficient for most applications. It can, however,
1692also be extended to work with new data types and new ways of interpreting the
1693same data. See the <a href="#customparser">Writing a Custom Parser</a> for more
1694details on this type of library extension.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1695
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1696<ul>
1697
1698<li><a name="genericparser">The <b>generic <tt>parser&lt;t&gt;</tt> parser</b></a>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1699can be used to map strings values to any data type, through the use of the <a
1700href="#cl::values">cl::values</a> property, which specifies the mapping
1701information. The most common use of this parser is for parsing enum values,
1702which allows you to use the CommandLine library for all of the error checking to
1703make sure that only valid enum values are specified (as opposed to accepting
1704arbitrary strings). Despite this, however, the generic parser class can be used
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1705for any data type.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1706
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1707<li><a name="boolparser">The <b><tt>parser&lt;bool&gt;</tt> specialization</b></a>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1708is used to convert boolean strings to a boolean value. Currently accepted
1709strings are "<tt>true</tt>", "<tt>TRUE</tt>", "<tt>True</tt>", "<tt>1</tt>",
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1710"<tt>false</tt>", "<tt>FALSE</tt>", "<tt>False</tt>", and "<tt>0</tt>".</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1711
Dale Johannesen10c5ccc2007-05-22 18:32:34 +0000[diff] [blame]1712<li><a name="boolOrDefaultparser">The <b><tt>parser&lt;boolOrDefault&gt;</tt>
1713 specialization</b></a> is used for cases where the value is boolean,
1714but we also need to know whether the option was specified at all. boolOrDefault
1715is an enum with 3 values, BOU_UNSET, BOU_TRUE and BOU_FALSE. This parser accepts
1716the same strings as <b><tt>parser&lt;bool&gt;</tt></b>.</li>
1717
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1718<li><a name="stringparser">The <b><tt>parser&lt;string&gt;</tt>
1719specialization</b></a> simply stores the parsed string into the string value
1720specified. No conversion or modification of the data is performed.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1721
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1722<li><a name="intparser">The <b><tt>parser&lt;int&gt;</tt> specialization</b></a>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1723uses the C <tt>strtol</tt> function to parse the string input. As such, it will
1724accept a decimal number (with an optional '+' or '-' prefix) which must start
1725with a non-zero digit. It accepts octal numbers, which are identified with a
1726'<tt>0</tt>' prefix digit, and hexadecimal numbers with a prefix of
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1727'<tt>0x</tt>' or '<tt>0X</tt>'.</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1728
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1729<li><a name="doubleparser">The <b><tt>parser&lt;double&gt;</tt></b></a> and
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1730<b><tt>parser&lt;float&gt;</tt> specializations</b> use the standard C
1731<tt>strtod</tt> function to convert floating point strings into floating point
1732values. As such, a broad range of string formats is supported, including
1733exponential notation (ex: <tt>1.7e15</tt>) and properly supports locales.
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1734</li>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1735
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1736</ul>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]1737
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1738</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]1739
1740<!-- *********************************************************************** -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1741<div class="doc_section">
1742 <a name="extensionguide">Extension Guide</a>
1743</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]1744<!-- *********************************************************************** -->
1745
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1746<div class="doc_text">
1747
1748<p>Although the CommandLine library has a lot of functionality built into it
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1749already (as discussed previously), one of its true strengths lie in its
1750extensibility. This section discusses how the CommandLine library works under
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1751the covers and illustrates how to do some simple, common, extensions.</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1752
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1753</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]1754
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1755<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1756<div class="doc_subsection">
1757 <a name="customparser">Writing a custom parser</a>
1758</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1759
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1760<div class="doc_text">
1761
1762<p>One of the simplest and most common extensions is the use of a custom parser.
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1763As <a href="#builtinparsers">discussed previously</a>, parsers are the portion
1764of the CommandLine library that turns string input from the user into a
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1765particular parsed data type, validating the input in the process.</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1766
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1767<p>There are two ways to use a new parser:</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1768
1769<ol>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1770
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1771<li>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1772
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1773<p>Specialize the <a href="#genericparser"><tt>cl::parser</tt></a> template for
1774your custom data type.<p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1775
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1776<p>This approach has the advantage that users of your custom data type will
1777automatically use your custom parser whenever they define an option with a value
1778type of your data type. The disadvantage of this approach is that it doesn't
Jim Laskey88b5e792006-07-31 20:18:49 +0000[diff] [blame]1779work if your fundamental data type is something that is already supported.</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1780
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1781</li>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1782
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1783<li>
1784
1785<p>Write an independent class, using it explicitly from options that need
1786it.</p>
1787
1788<p>This approach works well in situations where you would line to parse an
1789option using special syntax for a not-very-special data-type. The drawback of
1790this approach is that users of your parser have to be aware that they are using
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1791your parser instead of the builtin ones.</p>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1792
1793</li>
1794
1795</ol>
1796
1797<p>To guide the discussion, we will discuss a custom parser that accepts file
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1798sizes, specified with an optional unit after the numeric size. For example, we
1799would like to parse "102kb", "41M", "1G" into the appropriate integer value. In
1800this case, the underlying data type we want to parse into is
1801'<tt>unsigned</tt>'. We choose approach #2 above because we don't want to make
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1802this the default for all <tt>unsigned</tt> options.</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1803
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1804<p>To start out, we declare our new <tt>FileSizeParser</tt> class:</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1805
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1806<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1807<b>struct</b> FileSizeParser : <b>public</b> cl::basic_parser&lt;<b>unsigned</b>&gt; {
1808 <i>// parse - Return true on error.</i>
1809 <b>bool</b> parse(cl::Option &amp;O, <b>const char</b> *ArgName, <b>const</b> std::string &amp;ArgValue,
1810 <b>unsigned</b> &amp;Val);
1811};
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1812</pre></div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1813
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1814<p>Our new class inherits from the <tt>cl::basic_parser</tt> template class to
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1815fill in the default, boiler plate code for us. We give it the data type that
1816we parse into, the last argument to the <tt>parse</tt> method, so that clients of
1817our custom parser know what object type to pass in to the parse method. (Here we
1818declare that we parse into '<tt>unsigned</tt>' variables.)</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1819
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1820<p>For most purposes, the only method that must be implemented in a custom
1821parser is the <tt>parse</tt> method. The <tt>parse</tt> method is called
1822whenever the option is invoked, passing in the option itself, the option name,
1823the string to parse, and a reference to a return value. If the string to parse
Chris Lattner204e4a22008-01-09 19:28:50 +0000[diff] [blame]1824is not well-formed, the parser should output an error message and return true.
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1825Otherwise it should return false and set '<tt>Val</tt>' to the parsed value. In
1826our example, we implement <tt>parse</tt> as:</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1827
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1828<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1829<b>bool</b> FileSizeParser::parse(cl::Option &amp;O, <b>const char</b> *ArgName,
1830 <b>const</b> std::string &amp;Arg, <b>unsigned</b> &amp;Val) {
1831 <b>const char</b> *ArgStart = Arg.c_str();
1832 <b>char</b> *End;
Anton Korobeynikov581ba342008-02-20 12:38:31 +0000[diff] [blame]1833
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1834 <i>// Parse integer part, leaving 'End' pointing to the first non-integer char</i>
1835 Val = (unsigned)strtol(ArgStart, &amp;End, 0);
1836
1837 <b>while</b> (1) {
1838 <b>switch</b> (*End++) {
Chris Lattnerd50b29a2005-08-22 16:24:25 +0000[diff] [blame]1839 <b>case</b> 0: <b>return</b> false; <i>// No error</i>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1840 <b>case</b> 'i': <i>// Ignore the 'i' in KiB if people use that</i>
1841 <b>case</b> 'b': <b>case</b> 'B': <i>// Ignore B suffix</i>
1842 <b>break</b>;
1843
1844 <b>case</b> 'g': <b>case</b> 'G': Val *= 1024*1024*1024; <b>break</b>;
1845 <b>case</b> 'm': <b>case</b> 'M': Val *= 1024*1024; <b>break</b>;
1846 <b>case</b> 'k': <b>case</b> 'K': Val *= 1024; <b>break</b>;
1847
1848 default:
1849 <i>// Print an error message if unrecognized character!</i>
1850 <b>return</b> O.error(": '" + Arg + "' value invalid for file size argument!");
1851 }
1852 }
1853}
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1854</pre></div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1855
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1856<p>This function implements a very simple parser for the kinds of strings we are
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1857interested in. Although it has some holes (it allows "<tt>123KKK</tt>" for
1858example), it is good enough for this example. Note that we use the option
1859itself to print out the error message (the <tt>error</tt> method always returns
1860true) in order to get a nice error message (shown below). Now that we have our
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1861parser class, we can use it like this:</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1862
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1863<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1864<b>static</b> <a href="#cl::opt">cl::opt</a>&lt;<b>unsigned</b>, <b>false</b>, FileSizeParser&gt;
1865MFS(<i>"max-file-size"</i>, <a href="#cl::desc">cl::desc</a>(<i>"Maximum file size to accept"</i>),
1866 <a href="#cl::value_desc">cl::value_desc</a>("<i>size</i>"));
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1867</pre></div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1868
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1869<p>Which adds this to the output of our program:</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1870
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1871<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1872OPTIONS:
1873 -help - display available options (--help-hidden for more)
1874 ...
1875 <b>-max-file-size=&lt;size&gt; - Maximum file size to accept</b>
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1876</pre></div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1877
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1878<p>And we can test that our parse works correctly now (the test program just
1879prints out the max-file-size argument value):</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1880
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1881<div class="doc_code"><pre>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1882$ ./test
1883MFS: 0
1884$ ./test -max-file-size=123MB
1885MFS: 128974848
1886$ ./test -max-file-size=3G
1887MFS: 3221225472
1888$ ./test -max-file-size=dog
1889-max-file-size option: 'dog' value invalid for file size argument!
Misha Brukman922bf922005-03-11 00:00:33 +0000[diff] [blame]1890</pre></div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1891
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1892<p>It looks like it works. The error message that we get is nice and helpful,
1893and we seem to accept reasonable file sizes. This wraps up the "custom parser"
1894tutorial.</p>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1895
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1896</div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1897
1898<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1899<div class="doc_subsection">
1900 <a name="explotingexternal">Exploiting external storage</a>
1901</div>
Chris Lattner74ea5a62002-08-07 18:27:04 +0000[diff] [blame]1902
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1903<div class="doc_text">
Reid Spencercf2bc3d2004-08-30 05:56:51 +0000[diff] [blame]1904 <p>Several of the LLVM libraries define static <tt>cl::opt</tt> instances that
1905 will automatically be included in any program that links with that library.
1906 This is a feature. However, sometimes it is necessary to know the value of the
1907 command line option outside of the library. In these cases the library does or
1908 should provide an external storage location that is accessible to users of the
1909 library. Examples of this include the <tt>llvm::DebugFlag</tt> exported by the
1910 <tt>lib/Support/Debug.cpp</tt> file and the <tt>llvm::TimePassesIsEnabled</tt>
1911 flag exported by the <tt>lib/VMCore/Pass.cpp</tt> file.</p>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1912
Reid Spencercf2bc3d2004-08-30 05:56:51 +0000[diff] [blame]1913<p>TODO: complete this section</p>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1914
1915</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1916
1917<!-- ======================================================================= -->
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1918<div class="doc_subsection">
1919 <a name="dynamicopts">Dynamically adding command line options</a>
1920</div>
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1921
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1922<div class="doc_text">
Chris Lattner50761292002-08-06 19:36:06 +0000[diff] [blame]1923
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1924<p>TODO: fill in this section</p>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]1925
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1926</div>
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]1927
Chris Lattnerba025252001-07-23 23:03:12 +0000[diff] [blame]1928<!-- *********************************************************************** -->
1929
1930<hr>
Misha Brukman374258e2004-05-12 18:42:35 +0000[diff] [blame]1931<address>
1932 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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1936
1937 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]1938 <a href="http://llvm.org">LLVM Compiler Infrastructure</a><br>
Misha Brukman7120c832003-11-07 18:11:14 +0000[diff] [blame]1939 Last modified: $Date$
Misha Brukman374258e2004-05-12 18:42:35 +0000[diff] [blame]1940</address>
Misha Brukmanc86e8b12003-10-24 19:59:21 +0000[diff] [blame]1941
1942</body>
1943</html>