blob: 98dfc9af0fe6c97246fea12a98eaea64d0e9cc6a [file] [log] [blame]
Chris Lattner1811fca2004-01-05 05:06:33 +00001<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4<head>
Bill Wendlinge9353d72009-05-17 05:52:39 +00005 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Chris Lattner1811fca2004-01-05 05:06:33 +00006 <title>Source Level Debugging with LLVM</title>
7 <link rel="stylesheet" href="llvm.css" type="text/css">
8</head>
9<body>
10
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +000011<h1>Source Level Debugging with LLVM</h1>
Chris Lattner1811fca2004-01-05 05:06:33 +000012
Reid Spencerc3c4c4f2004-11-01 08:19:36 +000013<table class="layout" style="width:100%">
14 <tr class="layout">
15 <td class="left">
Chris Lattner1811fca2004-01-05 05:06:33 +000016<ul>
Misha Brukmanf91d9942004-05-12 19:21:57 +000017 <li><a href="#introduction">Introduction</a>
Chris Lattner1811fca2004-01-05 05:06:33 +000018 <ol>
19 <li><a href="#phil">Philosophy behind LLVM debugging information</a></li>
Jim Laskey5dcfd562006-03-23 17:54:33 +000020 <li><a href="#consumers">Debug information consumers</a></li>
Chris Lattner1811fca2004-01-05 05:06:33 +000021 <li><a href="#debugopt">Debugging optimized code</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +000022 </ol></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +000023 <li><a href="#format">Debugging information format</a>
Chris Lattner1811fca2004-01-05 05:06:33 +000024 <ol>
Jim Laskey14edc932006-03-14 18:08:46 +000025 <li><a href="#debug_info_descriptors">Debug information descriptors</a>
Chris Lattner1811fca2004-01-05 05:06:33 +000026 <ul>
Jim Laskey14edc932006-03-14 18:08:46 +000027 <li><a href="#format_compile_units">Compile unit descriptors</a></li>
Devang Patel59445db2010-03-09 00:44:10 +000028 <li><a href="#format_files">File descriptors</a></li>
Jim Laskey14edc932006-03-14 18:08:46 +000029 <li><a href="#format_global_variables">Global variable descriptors</a></li>
30 <li><a href="#format_subprograms">Subprogram descriptors</a></li>
Jim Laskey9dcffe72006-03-15 19:10:52 +000031 <li><a href="#format_blocks">Block descriptors</a></li>
Jim Laskey14edc932006-03-14 18:08:46 +000032 <li><a href="#format_basic_type">Basic type descriptors</a></li>
33 <li><a href="#format_derived_type">Derived type descriptors</a></li>
34 <li><a href="#format_composite_type">Composite type descriptors</a></li>
35 <li><a href="#format_subrange">Subrange descriptors</a></li>
36 <li><a href="#format_enumeration">Enumerator descriptors</a></li>
Jim Laskey5dcfd562006-03-23 17:54:33 +000037 <li><a href="#format_variables">Local variables</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +000038 </ul></li>
Jim Laskey14edc932006-03-14 18:08:46 +000039 <li><a href="#format_common_intrinsics">Debugger intrinsic functions</a>
40 <ul>
Jim Laskey14edc932006-03-14 18:08:46 +000041 <li><a href="#format_common_declare">llvm.dbg.declare</a></li>
Victor Hernandez0b62cc62010-01-11 22:53:48 +000042 <li><a href="#format_common_value">llvm.dbg.value</a></li>
Jim Laskey14edc932006-03-14 18:08:46 +000043 </ul></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +000044 </ol></li>
Devang Patel4da997b2009-11-25 23:28:01 +000045 <li><a href="#format_common_lifetime">Object lifetimes and scoping</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +000046 <li><a href="#ccxx_frontend">C/C++ front-end specific debug information</a>
Chris Lattner1811fca2004-01-05 05:06:33 +000047 <ol>
Jim Laskey14edc932006-03-14 18:08:46 +000048 <li><a href="#ccxx_compile_units">C/C++ source file information</a></li>
49 <li><a href="#ccxx_global_variable">C/C++ global variable information</a></li>
50 <li><a href="#ccxx_subprogram">C/C++ function information</a></li>
51 <li><a href="#ccxx_basic_types">C/C++ basic types</a></li>
52 <li><a href="#ccxx_derived_types">C/C++ derived types</a></li>
53 <li><a href="#ccxx_composite_types">C/C++ struct/union types</a></li>
54 <li><a href="#ccxx_enumeration_types">C/C++ enumeration types</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +000055 </ol></li>
Chris Lattner1811fca2004-01-05 05:06:33 +000056</ul>
Misha Brukmanf91d9942004-05-12 19:21:57 +000057</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +000058<td class="right">
Misha Brukman3c1f8e72004-05-12 21:26:16 +000059<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247"
Misha Brukmanf91d9942004-05-12 19:21:57 +000060height="369">
61</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +000062</tr></table>
Misha Brukmanf91d9942004-05-12 19:21:57 +000063
Chris Lattner020e1fc2004-05-23 21:07:27 +000064<div class="doc_author">
Jim Laskey14edc932006-03-14 18:08:46 +000065 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
Jim Laskey6e8a2f42007-03-14 19:32:21 +000066 and <a href="mailto:jlaskey@mac.com">Jim Laskey</a></p>
Chris Lattner020e1fc2004-05-23 21:07:27 +000067</div>
68
Chris Lattner1811fca2004-01-05 05:06:33 +000069
70<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +000071<h2><a name="introduction">Introduction</a></h2>
Misha Brukmancda6a9b2004-12-09 20:27:37 +000072<!-- *********************************************************************** -->
Chris Lattner1811fca2004-01-05 05:06:33 +000073
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +000074<div>
Chris Lattner1811fca2004-01-05 05:06:33 +000075
76<p>This document is the central repository for all information pertaining to
Bill Wendlinge9353d72009-05-17 05:52:39 +000077 debug information in LLVM. It describes the <a href="#format">actual format
78 that the LLVM debug information</a> takes, which is useful for those
79 interested in creating front-ends or dealing directly with the information.
Chris Lattnercb3f64f2009-07-18 21:47:15 +000080 Further, this document provides specific examples of what debug information
Chris Lattner92ec3d12011-01-18 06:12:10 +000081 for C/C++ looks like.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +000082
Chris Lattner1811fca2004-01-05 05:06:33 +000083<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +000084<h3>
Chris Lattner1811fca2004-01-05 05:06:33 +000085 <a name="phil">Philosophy behind LLVM debugging information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +000086</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +000087
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +000088<div>
Chris Lattner1811fca2004-01-05 05:06:33 +000089
Misha Brukmanf91d9942004-05-12 19:21:57 +000090<p>The idea of the LLVM debugging information is to capture how the important
Bill Wendlinge9353d72009-05-17 05:52:39 +000091 pieces of the source-language's Abstract Syntax Tree map onto LLVM code.
92 Several design aspects have shaped the solution that appears here. The
93 important ones are:</p>
Chris Lattner1811fca2004-01-05 05:06:33 +000094
Misha Brukmanf91d9942004-05-12 19:21:57 +000095<ul>
Bill Wendlinge9353d72009-05-17 05:52:39 +000096 <li>Debugging information should have very little impact on the rest of the
97 compiler. No transformations, analyses, or code generators should need to
98 be modified because of debugging information.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +000099
Bill Wendlinge9353d72009-05-17 05:52:39 +0000100 <li>LLVM optimizations should interact in <a href="#debugopt">well-defined and
101 easily described ways</a> with the debugging information.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000102
Bill Wendlinge9353d72009-05-17 05:52:39 +0000103 <li>Because LLVM is designed to support arbitrary programming languages,
104 LLVM-to-LLVM tools should not need to know anything about the semantics of
105 the source-level-language.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000106
Bill Wendlinge9353d72009-05-17 05:52:39 +0000107 <li>Source-level languages are often <b>widely</b> different from one another.
108 LLVM should not put any restrictions of the flavor of the source-language,
109 and the debugging information should work with any language.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000110
Bill Wendlinge9353d72009-05-17 05:52:39 +0000111 <li>With code generator support, it should be possible to use an LLVM compiler
112 to compile a program to native machine code and standard debugging
113 formats. This allows compatibility with traditional machine-code level
114 debuggers, like GDB or DBX.</li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000115</ul>
Chris Lattner1811fca2004-01-05 05:06:33 +0000116
Bill Wendlinge9353d72009-05-17 05:52:39 +0000117<p>The approach used by the LLVM implementation is to use a small set
118 of <a href="#format_common_intrinsics">intrinsic functions</a> to define a
119 mapping between LLVM program objects and the source-level objects. The
Devang Patel80ae3492009-08-28 23:24:31 +0000120 description of the source-level program is maintained in LLVM metadata
121 in an <a href="#ccxx_frontend">implementation-defined format</a>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000122 (the C/C++ front-end currently uses working draft 7 of
123 the <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3
124 standard</a>).</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000125
Jim Laskey14edc932006-03-14 18:08:46 +0000126<p>When a program is being debugged, a debugger interacts with the user and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000127 turns the stored debug information into source-language specific information.
128 As such, a debugger must be aware of the source-language, and is thus tied to
129 a specific language or family of languages.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000130
131</div>
132
Chris Lattner1811fca2004-01-05 05:06:33 +0000133<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000134<h3>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000135 <a name="consumers">Debug information consumers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000136</h3>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000137
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000138<div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000139
Jim Laskey5dcfd562006-03-23 17:54:33 +0000140<p>The role of debug information is to provide meta information normally
Bill Wendlinge9353d72009-05-17 05:52:39 +0000141 stripped away during the compilation process. This meta information provides
142 an LLVM user a relationship between generated code and the original program
143 source code.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000144
Chris Lattner904f2172010-04-05 04:11:11 +0000145<p>Currently, debug information is consumed by DwarfDebug to produce dwarf
Bill Wendlinge9353d72009-05-17 05:52:39 +0000146 information used by the gdb debugger. Other targets could use the same
147 information to produce stabs or other debug forms.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000148
149<p>It would also be reasonable to use debug information to feed profiling tools
Bill Wendlinge9353d72009-05-17 05:52:39 +0000150 for analysis of generated code, or, tools for reconstructing the original
151 source from generated code.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000152
153<p>TODO - expound a bit more.</p>
154
155</div>
156
157<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000158<h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000159 <a name="debugopt">Debugging optimized code</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000160</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000161
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000162<div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000163
Misha Brukmanf91d9942004-05-12 19:21:57 +0000164<p>An extremely high priority of LLVM debugging information is to make it
Bill Wendlinge9353d72009-05-17 05:52:39 +0000165 interact well with optimizations and analysis. In particular, the LLVM debug
166 information provides the following guarantees:</p>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000167
168<ul>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000169 <li>LLVM debug information <b>always provides information to accurately read
170 the source-level state of the program</b>, regardless of which LLVM
171 optimizations have been run, and without any modification to the
172 optimizations themselves. However, some optimizations may impact the
173 ability to modify the current state of the program with a debugger, such
174 as setting program variables, or calling functions that have been
175 deleted.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000176
Bill Wendlinge9353d72009-05-17 05:52:39 +0000177 <li>As desired, LLVM optimizations can be upgraded to be aware of the LLVM
178 debugging information, allowing them to update the debugging information
179 as they perform aggressive optimizations. This means that, with effort,
180 the LLVM optimizers could optimize debug code just as well as non-debug
181 code.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000182
Devang Patel5c26a852011-05-31 17:45:27 +0000183 <li>LLVM debug information does not prevent optimizations from
Bill Wendlinge9353d72009-05-17 05:52:39 +0000184 happening (for example inlining, basic block reordering/merging/cleanup,
Devang Patel1d81ea82011-05-31 18:06:14 +0000185 tail duplication, etc).</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000186
Bill Wendlinge9353d72009-05-17 05:52:39 +0000187 <li>LLVM debug information is automatically optimized along with the rest of
188 the program, using existing facilities. For example, duplicate
189 information is automatically merged by the linker, and unused information
190 is automatically removed.</li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000191</ul>
Chris Lattner1811fca2004-01-05 05:06:33 +0000192
Misha Brukmanf91d9942004-05-12 19:21:57 +0000193<p>Basically, the debug information allows you to compile a program with
Bill Wendlinge9353d72009-05-17 05:52:39 +0000194 "<tt>-O0 -g</tt>" and get full debug information, allowing you to arbitrarily
195 modify the program as it executes from a debugger. Compiling a program with
196 "<tt>-O3 -g</tt>" gives you full debug information that is always available
197 and accurate for reading (e.g., you get accurate stack traces despite tail
198 call elimination and inlining), but you might lose the ability to modify the
199 program and call functions where were optimized out of the program, or
200 inlined away completely.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000201
Misha Brukman39dcddf2008-12-16 02:54:22 +0000202<p><a href="TestingGuide.html#quicktestsuite">LLVM test suite</a> provides a
Bill Wendlinge9353d72009-05-17 05:52:39 +0000203 framework to test optimizer's handling of debugging information. It can be
204 run like this:</p>
Devang Patelb885a912008-11-21 19:35:57 +0000205
206<div class="doc_code">
207<pre>
208% cd llvm/projects/test-suite/MultiSource/Benchmarks # or some other level
209% make TEST=dbgopt
210</pre>
211</div>
212
Bill Wendlinge9353d72009-05-17 05:52:39 +0000213<p>This will test impact of debugging information on optimization passes. If
214 debugging information influences optimization passes then it will be reported
215 as a failure. See <a href="TestingGuide.html">TestingGuide</a> for more
216 information on LLVM test infrastructure and how to run various tests.</p>
Devang Patelb885a912008-11-21 19:35:57 +0000217
Chris Lattner1811fca2004-01-05 05:06:33 +0000218</div>
219
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000220</div>
221
Chris Lattner1811fca2004-01-05 05:06:33 +0000222<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000223<h2>
Chris Lattner941515c2004-01-06 05:31:32 +0000224 <a name="format">Debugging information format</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000225</h2>
Chris Lattner1811fca2004-01-05 05:06:33 +0000226<!-- *********************************************************************** -->
227
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000228<div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000229
230<p>LLVM debugging information has been carefully designed to make it possible
Bill Wendlinge9353d72009-05-17 05:52:39 +0000231 for the optimizer to optimize the program and debugging information without
232 necessarily having to know anything about debugging information. In
John Criswell2a4b0802010-03-17 15:01:50 +0000233 particular, the use of metadata avoids duplicated debugging information from
Devang Patel80ae3492009-08-28 23:24:31 +0000234 the beginning, and the global dead code elimination pass automatically
235 deletes debugging information for a function if it decides to delete the
236 function. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000237
238<p>To do this, most of the debugging information (descriptors for types,
Bill Wendlinge9353d72009-05-17 05:52:39 +0000239 variables, functions, source files, etc) is inserted by the language
Devang Patel80ae3492009-08-28 23:24:31 +0000240 front-end in the form of LLVM metadata. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000241
Jim Laskey14edc932006-03-14 18:08:46 +0000242<p>Debug information is designed to be agnostic about the target debugger and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000243 debugging information representation (e.g. DWARF/Stabs/etc). It uses a
Devang Patel80ae3492009-08-28 23:24:31 +0000244 generic pass to decode the information that represents variables, types,
245 functions, namespaces, etc: this allows for arbitrary source-language
246 semantics and type-systems to be used, as long as there is a module
247 written for the target debugger to interpret the information. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000248
Misha Brukmanf91d9942004-05-12 19:21:57 +0000249<p>To provide basic functionality, the LLVM debugger does have to make some
Bill Wendlinge9353d72009-05-17 05:52:39 +0000250 assumptions about the source-level language being debugged, though it keeps
251 these to a minimum. The only common features that the LLVM debugger assumes
Devang Patel59445db2010-03-09 00:44:10 +0000252 exist are <a href="#format_files">source files</a>,
Bill Wendlinge9353d72009-05-17 05:52:39 +0000253 and <a href="#format_global_variables">program objects</a>. These abstract
254 objects are used by a debugger to form stack traces, show information about
255 local variables, etc.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000256
257<p>This section of the documentation first describes the representation aspects
Bill Wendlinge9353d72009-05-17 05:52:39 +0000258 common to any source-language. The <a href="#ccxx_frontend">next section</a>
259 describes the data layout conventions used by the C and C++ front-ends.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000260
Chris Lattner1811fca2004-01-05 05:06:33 +0000261<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000262<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000263 <a name="debug_info_descriptors">Debug information descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000264</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000265
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000266<div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000267
Jim Laskey14edc932006-03-14 18:08:46 +0000268<p>In consideration of the complexity and volume of debug information, LLVM
Devang Patel80ae3492009-08-28 23:24:31 +0000269 provides a specification for well formed debug descriptors. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000270
Jim Laskey14edc932006-03-14 18:08:46 +0000271<p>Consumers of LLVM debug information expect the descriptors for program
Bill Wendlinge9353d72009-05-17 05:52:39 +0000272 objects to start in a canonical format, but the descriptors can include
273 additional information appended at the end that is source-language
274 specific. All LLVM debugging information is versioned, allowing backwards
275 compatibility in the case that the core structures need to change in some
276 way. Also, all debugging information objects start with a tag to indicate
277 what type of object it is. The source-language is allowed to define its own
278 objects, by using unreserved tag numbers. We recommend using with tags in
Benjamin Kramer0f420382009-10-12 14:46:08 +0000279 the range 0x1000 through 0x2000 (there is a defined enum DW_TAG_user_base =
Bill Wendlinge9353d72009-05-17 05:52:39 +0000280 0x1000.)</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000281
Devang Patel80ae3492009-08-28 23:24:31 +0000282<p>The fields of debug descriptors used internally by LLVM
Nick Lewyckya87014f2010-03-31 07:50:17 +0000283 are restricted to only the simple data types <tt>i32</tt>, <tt>i1</tt>,
284 <tt>float</tt>, <tt>double</tt>, <tt>mdstring</tt> and <tt>mdnode</tt>. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000285
Bill Wendlinge9353d72009-05-17 05:52:39 +0000286<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000287<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000288!1 = metadata !{
Nick Lewyckya87014f2010-03-31 07:50:17 +0000289 i32, ;; A tag
Bill Wendlinge9353d72009-05-17 05:52:39 +0000290 ...
291}
Misha Brukmanf91d9942004-05-12 19:21:57 +0000292</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000293</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000294
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000295<p><a name="LLVMDebugVersion">The first field of a descriptor is always an
Nick Lewyckya87014f2010-03-31 07:50:17 +0000296 <tt>i32</tt> containing a tag value identifying the content of the
Bill Wendlinge9353d72009-05-17 05:52:39 +0000297 descriptor. The remaining fields are specific to the descriptor. The values
298 of tags are loosely bound to the tag values of DWARF information entries.
299 However, that does not restrict the use of the information supplied to DWARF
300 targets. To facilitate versioning of debug information, the tag is augmented
Nick Lewyckyf6e37112011-07-25 21:13:23 +0000301 with the current debug version (LLVMDebugVersion = 8 &lt;&lt; 16 or
302 0x80000 or 524288.)</a></p>
Jim Laskey14edc932006-03-14 18:08:46 +0000303
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000304<p>The details of the various descriptors follow.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000305
Jim Laskey14edc932006-03-14 18:08:46 +0000306<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000307<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000308 <a name="format_compile_units">Compile unit descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000309</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000310
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000311<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000312
Bill Wendlinge9353d72009-05-17 05:52:39 +0000313<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000314<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000315!0 = metadata !{
316 i32, ;; Tag = 17 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
317 ;; (DW_TAG_compile_unit)
318 i32, ;; Unused field.
319 i32, ;; DWARF language identifier (ex. DW_LANG_C89)
320 metadata, ;; Source file name
321 metadata, ;; Source file directory (includes trailing slash)
322 metadata ;; Producer (ex. "4.0.1 LLVM (LLVM research group)")
323 i1, ;; True if this is a main compile unit.
324 i1, ;; True if this is optimized.
325 metadata, ;; Flags
326 i32 ;; Runtime version
Devang Patel24a674b2011-09-09 17:07:15 +0000327 metadata ;; List of enums types
328 metadata ;; List of retained types
329 metadata ;; List of subprograms
330 metadata ;; List of global variables
Bill Wendlinge9353d72009-05-17 05:52:39 +0000331}
Jim Laskey14edc932006-03-14 18:08:46 +0000332</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000333</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000334
Bill Wendlinge9353d72009-05-17 05:52:39 +0000335<p>These descriptors contain a source language ID for the file (we use the DWARF
336 3.0 ID numbers, such as <tt>DW_LANG_C89</tt>, <tt>DW_LANG_C_plus_plus</tt>,
337 <tt>DW_LANG_Cobol74</tt>, etc), three strings describing the filename,
338 working directory of the compiler, and an identifier string for the compiler
339 that produced it.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000340
Bill Wendlinge9353d72009-05-17 05:52:39 +0000341<p>Compile unit descriptors provide the root context for objects declared in a
Devang Patel09fa69e2011-05-03 16:18:28 +0000342 specific compilation unit. File descriptors are defined using this context.
343 These descriptors are collected by a named metadata
Devang Patel24a674b2011-09-09 17:07:15 +0000344 <tt>!llvm.dbg.cu</tt>. Compile unit descriptor keeps track of subprograms,
345 global variables and type information.
Jim Laskey14edc932006-03-14 18:08:46 +0000346
Devang Patel59445db2010-03-09 00:44:10 +0000347</div>
348
349<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000350<h4>
Devang Patel59445db2010-03-09 00:44:10 +0000351 <a name="format_files">File descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000352</h4>
Devang Patel59445db2010-03-09 00:44:10 +0000353
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000354<div>
Devang Patel59445db2010-03-09 00:44:10 +0000355
356<div class="doc_code">
357<pre>
358!0 = metadata !{
359 i32, ;; Tag = 41 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
360 ;; (DW_TAG_file_type)
361 metadata, ;; Source file name
362 metadata, ;; Source file directory (includes trailing slash)
Devang Pateleb1bb4e2011-08-16 22:09:43 +0000363 metadata ;; Unused
Devang Patel59445db2010-03-09 00:44:10 +0000364}
365</pre>
366</div>
367
John Criswell2a4b0802010-03-17 15:01:50 +0000368<p>These descriptors contain information for a file. Global variables and top
Devang Patel59445db2010-03-09 00:44:10 +0000369 level functions would be defined using this context.k File descriptors also
370 provide context for source line correspondence. </p>
371
372<p>Each input file is encoded as a separate file descriptor in LLVM debugging
Devang Pateleb1bb4e2011-08-16 22:09:43 +0000373 information output. </p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000374
Jim Laskey14edc932006-03-14 18:08:46 +0000375</div>
376
377<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000378<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000379 <a name="format_global_variables">Global variable descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000380</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000381
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000382<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000383
Bill Wendlinge9353d72009-05-17 05:52:39 +0000384<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000385<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000386!1 = metadata !{
387 i32, ;; Tag = 52 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
388 ;; (DW_TAG_variable)
389 i32, ;; Unused field.
390 metadata, ;; Reference to context descriptor
391 metadata, ;; Name
392 metadata, ;; Display name (fully qualified C++ name)
393 metadata, ;; MIPS linkage name (for C++)
Devang Patel59445db2010-03-09 00:44:10 +0000394 metadata, ;; Reference to file where defined
Devang Patel80ae3492009-08-28 23:24:31 +0000395 i32, ;; Line number where defined
396 metadata, ;; Reference to type descriptor
397 i1, ;; True if the global is local to compile unit (static)
398 i1, ;; True if the global is defined in the compile unit (not extern)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000399 {}* ;; Reference to the global variable
Bill Wendlinge9353d72009-05-17 05:52:39 +0000400}
Jim Laskey14edc932006-03-14 18:08:46 +0000401</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000402</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000403
404<p>These descriptors provide debug information about globals variables. The
Devang Patel1c6b6812011-03-29 17:27:08 +0000405provide details such as name, type and where the variable is defined. All
406global variables are collected by named metadata <tt>!llvm.dbg.gv</tt>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000407
408</div>
409
410<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000411<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000412 <a name="format_subprograms">Subprogram descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000413</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000414
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000415<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000416
Bill Wendlinge9353d72009-05-17 05:52:39 +0000417<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000418<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000419!2 = metadata !{
420 i32, ;; Tag = 46 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
421 ;; (DW_TAG_subprogram)
422 i32, ;; Unused field.
423 metadata, ;; Reference to context descriptor
424 metadata, ;; Name
425 metadata, ;; Display name (fully qualified C++ name)
426 metadata, ;; MIPS linkage name (for C++)
Devang Patel59445db2010-03-09 00:44:10 +0000427 metadata, ;; Reference to file where defined
Devang Patel80ae3492009-08-28 23:24:31 +0000428 i32, ;; Line number where defined
429 metadata, ;; Reference to type descriptor
430 i1, ;; True if the global is local to compile unit (static)
Devang Patel1d6bbd42011-04-22 23:10:17 +0000431 i1, ;; True if the global is defined in the compile unit (not extern)
432 i32, ;; Virtuality, e.g. dwarf::DW_VIRTUALITY__virtual
433 i32, ;; Index into a virtual function
Devang Patele89b7592010-06-04 22:49:55 +0000434 metadata, ;; indicates which base type contains the vtable pointer for the
435 ;; derived class
Devang Patel1d6bbd42011-04-22 23:10:17 +0000436 i1, ;; isArtificial
437 i1, ;; isOptimized
438 Function *,;; Pointer to LLVM function
439 metadata, ;; Lists function template parameters
440 metadata ;; Function declaration descriptor
Devang Patel59e27c52011-08-19 23:28:12 +0000441 metadata ;; List of function variables
Bill Wendlinge9353d72009-05-17 05:52:39 +0000442}
Jim Laskey14edc932006-03-14 18:08:46 +0000443</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000444</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000445
446<p>These descriptors provide debug information about functions, methods and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000447 subprograms. They provide details such as name, return types and the source
Devang Patel1c6b6812011-03-29 17:27:08 +0000448 location where the subprogram is defined.
449 All subprogram descriptors are collected by a named metadata
450 <tt>!llvm.dbg.sp</tt>.
451</p>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000452
453</div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000454
Jim Laskey9dcffe72006-03-15 19:10:52 +0000455<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000456<h4>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000457 <a name="format_blocks">Block descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000458</h4>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000459
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000460<div>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000461
Bill Wendlinge9353d72009-05-17 05:52:39 +0000462<div class="doc_code">
Jim Laskey9dcffe72006-03-15 19:10:52 +0000463<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000464!3 = metadata !{
Devang Patel9fbc6802010-10-04 16:51:59 +0000465 i32, ;; Tag = 11 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block)
Devang Patelcac38902010-10-01 22:45:00 +0000466 metadata,;; Reference to context descriptor
467 i32, ;; Line number
Devang Patelfb30b852011-03-08 16:25:29 +0000468 i32, ;; Column number
469 metadata,;; Reference to source file
470 i32 ;; Unique ID to identify blocks from a template function
Bill Wendlinge9353d72009-05-17 05:52:39 +0000471}
Jim Laskey9dcffe72006-03-15 19:10:52 +0000472</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000473</div>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000474
475<p>These descriptors provide debug information about nested blocks within a
Devang Patelcac38902010-10-01 22:45:00 +0000476 subprogram. The line number and column numbers are used to dinstinguish
477 two lexical blocks at same depth. </p>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000478
Jim Laskey14edc932006-03-14 18:08:46 +0000479</div>
480
481<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000482<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000483 <a name="format_basic_type">Basic type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000484</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000485
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000486<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000487
Bill Wendlinge9353d72009-05-17 05:52:39 +0000488<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000489<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000490!4 = metadata !{
491 i32, ;; Tag = 36 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
492 ;; (DW_TAG_base_type)
Devang Pateleb1bb4e2011-08-16 22:09:43 +0000493 metadata, ;; Reference to context
Devang Patel80ae3492009-08-28 23:24:31 +0000494 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000495 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000496 i32, ;; Line number where defined (may be 0)
497 i64, ;; Size in bits
498 i64, ;; Alignment in bits
499 i64, ;; Offset in bits
500 i32, ;; Flags
501 i32 ;; DWARF type encoding
Bill Wendlinge9353d72009-05-17 05:52:39 +0000502}
Jim Laskey14edc932006-03-14 18:08:46 +0000503</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000504</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000505
506<p>These descriptors define primitive types used in the code. Example int, bool
Bill Wendlinge9353d72009-05-17 05:52:39 +0000507 and float. The context provides the scope of the type, which is usually the
Devang Pateleb1bb4e2011-08-16 22:09:43 +0000508 top level. Since basic types are not usually user defined the context
Bill Wendlinge9353d72009-05-17 05:52:39 +0000509 and line number can be left as NULL and 0. The size, alignment and offset
510 are expressed in bits and can be 64 bit values. The alignment is used to
511 round the offset when embedded in a
512 <a href="#format_composite_type">composite type</a> (example to keep float
513 doubles on 64 bit boundaries.) The offset is the bit offset if embedded in
514 a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000515
516<p>The type encoding provides the details of the type. The values are typically
Bill Wendlinge9353d72009-05-17 05:52:39 +0000517 one of the following:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000518
Bill Wendlinge9353d72009-05-17 05:52:39 +0000519<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000520<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000521DW_ATE_address = 1
522DW_ATE_boolean = 2
523DW_ATE_float = 4
524DW_ATE_signed = 5
525DW_ATE_signed_char = 6
526DW_ATE_unsigned = 7
527DW_ATE_unsigned_char = 8
Jim Laskey14edc932006-03-14 18:08:46 +0000528</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000529</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000530
531</div>
532
533<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000534<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000535 <a name="format_derived_type">Derived type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000536</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000537
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000538<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000539
Bill Wendlinge9353d72009-05-17 05:52:39 +0000540<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000541<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000542!5 = metadata !{
543 i32, ;; Tag (see below)
544 metadata, ;; Reference to context
545 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000546 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000547 i32, ;; Line number where defined (may be 0)
Devang Patelbed5e7d2010-10-01 19:19:30 +0000548 i64, ;; Size in bits
549 i64, ;; Alignment in bits
550 i64, ;; Offset in bits
Devang Patel514b4002011-04-16 00:11:51 +0000551 metadata, ;; Reference to type derived from
552 metadata, ;; (optional) Name of the Objective C property assoicated with
553 ;; Objective-C an ivar
554 metadata, ;; (optional) Name of the Objective C property getter selector.
555 metadata, ;; (optional) Name of the Objective C property setter selector.
556 i32 ;; (optional) Objective C property attributes.
Bill Wendlinge9353d72009-05-17 05:52:39 +0000557}
Jim Laskey14edc932006-03-14 18:08:46 +0000558</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000559</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000560
561<p>These descriptors are used to define types derived from other types. The
562value of the tag varies depending on the meaning. The following are possible
Misha Brukman39dcddf2008-12-16 02:54:22 +0000563tag values:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000564
Bill Wendlinge9353d72009-05-17 05:52:39 +0000565<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000566<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000567DW_TAG_formal_parameter = 5
568DW_TAG_member = 13
569DW_TAG_pointer_type = 15
570DW_TAG_reference_type = 16
571DW_TAG_typedef = 22
572DW_TAG_const_type = 38
573DW_TAG_volatile_type = 53
574DW_TAG_restrict_type = 55
Jim Laskey14edc932006-03-14 18:08:46 +0000575</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000576</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000577
Bill Wendlinge9353d72009-05-17 05:52:39 +0000578<p><tt>DW_TAG_member</tt> is used to define a member of
579 a <a href="#format_composite_type">composite type</a>
580 or <a href="#format_subprograms">subprogram</a>. The type of the member is
581 the <a href="#format_derived_type">derived
582 type</a>. <tt>DW_TAG_formal_parameter</tt> is used to define a member which
583 is a formal argument of a subprogram.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000584
Bill Wendlinge9353d72009-05-17 05:52:39 +0000585<p><tt>DW_TAG_typedef</tt> is used to provide a name for the derived type.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000586
Bill Wendlinge9353d72009-05-17 05:52:39 +0000587<p><tt>DW_TAG_pointer_type</tt>,<tt>DW_TAG_reference_type</tt>,
588 <tt>DW_TAG_const_type</tt>, <tt>DW_TAG_volatile_type</tt>
589 and <tt>DW_TAG_restrict_type</tt> are used to qualify
590 the <a href="#format_derived_type">derived type</a>. </p>
Jim Laskey14edc932006-03-14 18:08:46 +0000591
592<p><a href="#format_derived_type">Derived type</a> location can be determined
Devang Pateleb1bb4e2011-08-16 22:09:43 +0000593 from the context and line number. The size, alignment and offset are
Bill Wendlinge9353d72009-05-17 05:52:39 +0000594 expressed in bits and can be 64 bit values. The alignment is used to round
595 the offset when embedded in a <a href="#format_composite_type">composite
596 type</a> (example to keep float doubles on 64 bit boundaries.) The offset is
597 the bit offset if embedded in a <a href="#format_composite_type">composite
598 type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000599
Devang Patel7846c1e2011-02-03 00:22:17 +0000600<p>Note that the <tt>void *</tt> type is expressed as a type derived from NULL.
601</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000602
603</div>
604
605<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000606<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000607 <a name="format_composite_type">Composite type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000608</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000609
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000610<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000611
Bill Wendlinge9353d72009-05-17 05:52:39 +0000612<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000613<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000614!6 = metadata !{
615 i32, ;; Tag (see below)
616 metadata, ;; Reference to context
617 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000618 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000619 i32, ;; Line number where defined (may be 0)
620 i64, ;; Size in bits
621 i64, ;; Alignment in bits
622 i64, ;; Offset in bits
623 i32, ;; Flags
624 metadata, ;; Reference to type derived from
625 metadata, ;; Reference to array of member descriptors
626 i32 ;; Runtime languages
Bill Wendlinge9353d72009-05-17 05:52:39 +0000627}
Jim Laskey14edc932006-03-14 18:08:46 +0000628</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000629</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000630
631<p>These descriptors are used to define types that are composed of 0 or more
632elements. The value of the tag varies depending on the meaning. The following
Misha Brukman39dcddf2008-12-16 02:54:22 +0000633are possible tag values:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000634
Bill Wendlinge9353d72009-05-17 05:52:39 +0000635<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000636<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000637DW_TAG_array_type = 1
638DW_TAG_enumeration_type = 4
639DW_TAG_structure_type = 19
640DW_TAG_union_type = 23
641DW_TAG_vector_type = 259
Bruno Cardoso Lopes9d809ca2009-05-29 17:08:57 +0000642DW_TAG_subroutine_type = 21
643DW_TAG_inheritance = 28
Jim Laskey14edc932006-03-14 18:08:46 +0000644</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000645</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000646
Jim Laskey19f964e2006-06-15 20:51:43 +0000647<p>The vector flag indicates that an array type is a native packed vector.</p>
648
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000649<p>The members of array types (tag = <tt>DW_TAG_array_type</tt>) or vector types
Bill Wendlinge9353d72009-05-17 05:52:39 +0000650 (tag = <tt>DW_TAG_vector_type</tt>) are <a href="#format_subrange">subrange
651 descriptors</a>, each representing the range of subscripts at that level of
652 indexing.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000653
654<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are
Bill Wendlinge9353d72009-05-17 05:52:39 +0000655 <a href="#format_enumeration">enumerator descriptors</a>, each representing
Devang Patel1c6b6812011-03-29 17:27:08 +0000656 the definition of enumeration value for the set. All enumeration type
657 descriptors are collected by named metadata <tt>!llvm.dbg.enum</tt>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000658
659<p>The members of structure (tag = <tt>DW_TAG_structure_type</tt>) or union (tag
Bill Wendlinge9353d72009-05-17 05:52:39 +0000660 = <tt>DW_TAG_union_type</tt>) types are any one of
661 the <a href="#format_basic_type">basic</a>,
662 <a href="#format_derived_type">derived</a>
663 or <a href="#format_composite_type">composite</a> type descriptors, each
664 representing a field member of the structure or union.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000665
Jim Laskey4771cca2006-08-21 21:21:06 +0000666<p>For C++ classes (tag = <tt>DW_TAG_structure_type</tt>), member descriptors
Bill Wendlinge9353d72009-05-17 05:52:39 +0000667 provide information about base classes, static members and member
668 functions. If a member is a <a href="#format_derived_type">derived type
669 descriptor</a> and has a tag of <tt>DW_TAG_inheritance</tt>, then the type
670 represents a base class. If the member of is
671 a <a href="#format_global_variables">global variable descriptor</a> then it
672 represents a static member. And, if the member is
673 a <a href="#format_subprograms">subprogram descriptor</a> then it represents
674 a member function. For static members and member
675 functions, <tt>getName()</tt> returns the members link or the C++ mangled
676 name. <tt>getDisplayName()</tt> the simplied version of the name.</p>
Jim Laskey4771cca2006-08-21 21:21:06 +0000677
Bill Wendlinge9353d72009-05-17 05:52:39 +0000678<p>The first member of subroutine (tag = <tt>DW_TAG_subroutine_type</tt>) type
679 elements is the return type for the subroutine. The remaining elements are
680 the formal arguments to the subroutine.</p>
Jim Laskey4810c262006-06-20 21:13:20 +0000681
Jim Laskey14edc932006-03-14 18:08:46 +0000682<p><a href="#format_composite_type">Composite type</a> location can be
Devang Pateleb1bb4e2011-08-16 22:09:43 +0000683 determined from the context and line number. The size, alignment and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000684 offset are expressed in bits and can be 64 bit values. The alignment is used
685 to round the offset when embedded in
686 a <a href="#format_composite_type">composite type</a> (as an example, to keep
687 float doubles on 64 bit boundaries.) The offset is the bit offset if embedded
688 in a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000689
690</div>
691
692<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000693<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000694 <a name="format_subrange">Subrange descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000695</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000696
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000697<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000698
Bill Wendlinge9353d72009-05-17 05:52:39 +0000699<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000700<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000701!42 = metadata !{
Bill Wendlinge9353d72009-05-17 05:52:39 +0000702 i32, ;; Tag = 33 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subrange_type)
703 i64, ;; Low value
704 i64 ;; High value
705}
Jim Laskey14edc932006-03-14 18:08:46 +0000706</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000707</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000708
709<p>These descriptors are used to define ranges of array subscripts for an array
Bill Wendlinge9353d72009-05-17 05:52:39 +0000710 <a href="#format_composite_type">composite type</a>. The low value defines
711 the lower bounds typically zero for C/C++. The high value is the upper
712 bounds. Values are 64 bit. High - low + 1 is the size of the array. If low
Devang Patel778947c2011-04-08 23:39:38 +0000713 > high the array bounds are not included in generated debugging information.
714</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000715
716</div>
717
718<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000719<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000720 <a name="format_enumeration">Enumerator descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000721</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000722
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000723<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000724
Bill Wendlinge9353d72009-05-17 05:52:39 +0000725<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000726<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000727!6 = metadata !{
728 i32, ;; Tag = 40 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
729 ;; (DW_TAG_enumerator)
730 metadata, ;; Name
731 i64 ;; Value
Bill Wendlinge9353d72009-05-17 05:52:39 +0000732}
Jim Laskey14edc932006-03-14 18:08:46 +0000733</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000734</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000735
Bill Wendlinge9353d72009-05-17 05:52:39 +0000736<p>These descriptors are used to define members of an
737 enumeration <a href="#format_composite_type">composite type</a>, it
738 associates the name to the value.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000739
740</div>
741
742<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000743<h4>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000744 <a name="format_variables">Local variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000745</h4>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000746
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000747<div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000748
749<div class="doc_code">
Jim Laskey5dcfd562006-03-23 17:54:33 +0000750<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000751!7 = metadata !{
752 i32, ;; Tag (see below)
753 metadata, ;; Context
754 metadata, ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000755 metadata, ;; Reference to file where defined
Devang Patele1aa67c2011-03-08 16:29:40 +0000756 i32, ;; 24 bit - Line number where defined
757 ;; 8 bit - Argument number. 1 indicates 1st argument.
Devang Patelac0a1f62011-07-27 18:14:50 +0000758 metadata, ;; Type descriptor
759 i32, ;; flags
760 metadata ;; (optional) Reference to inline location
Bill Wendlinge9353d72009-05-17 05:52:39 +0000761}
Jim Laskey5dcfd562006-03-23 17:54:33 +0000762</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000763</div>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000764
765<p>These descriptors are used to define variables local to a sub program. The
Bill Wendlinge9353d72009-05-17 05:52:39 +0000766 value of the tag depends on the usage of the variable:</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000767
Bill Wendlinge9353d72009-05-17 05:52:39 +0000768<div class="doc_code">
Jim Laskey5dcfd562006-03-23 17:54:33 +0000769<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000770DW_TAG_auto_variable = 256
771DW_TAG_arg_variable = 257
772DW_TAG_return_variable = 258
Jim Laskey5dcfd562006-03-23 17:54:33 +0000773</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000774</div>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000775
776<p>An auto variable is any variable declared in the body of the function. An
Bill Wendlinge9353d72009-05-17 05:52:39 +0000777 argument variable is any variable that appears as a formal argument to the
778 function. A return variable is used to track the result of a function and
779 has no source correspondent.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000780
Jim Laskey3481e122006-03-24 09:20:27 +0000781<p>The context is either the subprogram or block where the variable is defined.
Devang Pateleb1bb4e2011-08-16 22:09:43 +0000782 Name the source variable name. Context and line indicate where the
Bill Wendlinge9353d72009-05-17 05:52:39 +0000783 variable was defined. Type descriptor defines the declared type of the
784 variable.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000785
786</div>
787
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000788</div>
789
Jim Laskey5dcfd562006-03-23 17:54:33 +0000790<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000791<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000792 <a name="format_common_intrinsics">Debugger intrinsic functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000793</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000794
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000795<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000796
797<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to
Bill Wendlinge9353d72009-05-17 05:52:39 +0000798 provide debug information at various points in generated code.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000799
Jim Laskey14edc932006-03-14 18:08:46 +0000800<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000801<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000802 <a name="format_common_declare">llvm.dbg.declare</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000803</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000804
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000805<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000806<pre>
Devang Patel6df452c2010-10-01 19:22:16 +0000807 void %<a href="#format_common_declare">llvm.dbg.declare</a>(metadata, metadata)
Jim Laskey14edc932006-03-14 18:08:46 +0000808</pre>
809
Jim Laskey3481e122006-03-24 09:20:27 +0000810<p>This intrinsic provides information about a local element (ex. variable.) The
NAKAMURA Takumi6bd36d52011-04-09 09:51:57 +0000811 first argument is metadata holding alloca for the variable. The
Devang Patel9a8539c2011-02-01 17:22:12 +0000812 second argument is metadata containing description of the variable. </p>
Jim Laskey14edc932006-03-14 18:08:46 +0000813</div>
814
815<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000816<h4>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000817 <a name="format_common_value">llvm.dbg.value</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000818</h4>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000819
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000820<div>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000821<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000822 void %<a href="#format_common_value">llvm.dbg.value</a>(metadata, i64, metadata)
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000823</pre>
824
825<p>This intrinsic provides information when a user source variable is set to a
826 new value. The first argument is the new value (wrapped as metadata). The
827 second argument is the offset in the user source variable where the new value
Devang Patel9a8539c2011-02-01 17:22:12 +0000828 is written. The third argument is metadata containing description of the
829 user source variable. </p>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000830</div>
831
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000832</div>
833
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000834<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000835<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000836 <a name="format_common_lifetime">Object lifetimes and scoping</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000837</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000838
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000839<div>
Bill Wendling991b84e2009-12-01 00:53:11 +0000840<p>In many languages, the local variables in functions can have their lifetimes
841 or scopes limited to a subset of a function. In the C family of languages,
Bill Wendlinge9353d72009-05-17 05:52:39 +0000842 for example, variables are only live (readable and writable) within the
843 source block that they are defined in. In functional languages, values are
844 only readable after they have been defined. Though this is a very obvious
Bill Wendling991b84e2009-12-01 00:53:11 +0000845 concept, it is non-trivial to model in LLVM, because it has no notion of
Bill Wendlinge9353d72009-05-17 05:52:39 +0000846 scoping in this sense, and does not want to be tied to a language's scoping
847 rules.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000848
Bill Wendling991b84e2009-12-01 00:53:11 +0000849<p>In order to handle this, the LLVM debug format uses the metadata attached to
Nick Lewyckya87014f2010-03-31 07:50:17 +0000850 llvm instructions to encode line number and scoping information. Consider
851 the following C fragment, for example:</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000852
Bill Wendlinge9353d72009-05-17 05:52:39 +0000853<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000854<pre>
Chris Lattner1811fca2004-01-05 05:06:33 +00008551. void foo() {
Devang Patel4da997b2009-11-25 23:28:01 +00008562. int X = 21;
8573. int Y = 22;
Chris Lattner1811fca2004-01-05 05:06:33 +00008584. {
Devang Patel4da997b2009-11-25 23:28:01 +00008595. int Z = 23;
8606. Z = X;
Chris Lattner1811fca2004-01-05 05:06:33 +00008617. }
Devang Patel4da997b2009-11-25 23:28:01 +00008628. X = Y;
Chris Lattner1811fca2004-01-05 05:06:33 +00008639. }
Misha Brukmanf91d9942004-05-12 19:21:57 +0000864</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000865</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000866
Jim Laskey14edc932006-03-14 18:08:46 +0000867<p>Compiled to LLVM, this function would be represented like this:</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000868
Bill Wendlinge9353d72009-05-17 05:52:39 +0000869<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000870<pre>
Bill Wendling991b84e2009-12-01 00:53:11 +0000871define void @foo() nounwind ssp {
Jim Laskey14edc932006-03-14 18:08:46 +0000872entry:
Bill Wendling05252352009-12-01 00:59:58 +0000873 %X = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
874 %Y = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
875 %Z = alloca i32, align 4 ; &lt;i32*&gt; [#uses=3]
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000876 %0 = bitcast i32* %X to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000877 call void @llvm.dbg.declare(metadata !{i32 * %X}, metadata !0), !dbg !7
Devang Patel4da997b2009-11-25 23:28:01 +0000878 store i32 21, i32* %X, !dbg !8
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000879 %1 = bitcast i32* %Y to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000880 call void @llvm.dbg.declare(metadata !{i32 * %Y}, metadata !9), !dbg !10
Devang Patel4da997b2009-11-25 23:28:01 +0000881 store i32 22, i32* %Y, !dbg !11
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000882 %2 = bitcast i32* %Z to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000883 call void @llvm.dbg.declare(metadata !{i32 * %Z}, metadata !12), !dbg !14
Devang Patel4da997b2009-11-25 23:28:01 +0000884 store i32 23, i32* %Z, !dbg !15
Bill Wendling05252352009-12-01 00:59:58 +0000885 %tmp = load i32* %X, !dbg !16 ; &lt;i32&gt; [#uses=1]
886 %tmp1 = load i32* %Y, !dbg !16 ; &lt;i32&gt; [#uses=1]
887 %add = add nsw i32 %tmp, %tmp1, !dbg !16 ; &lt;i32&gt; [#uses=1]
Devang Patel4da997b2009-11-25 23:28:01 +0000888 store i32 %add, i32* %Z, !dbg !16
Bill Wendling05252352009-12-01 00:59:58 +0000889 %tmp2 = load i32* %Y, !dbg !17 ; &lt;i32&gt; [#uses=1]
Devang Patel4da997b2009-11-25 23:28:01 +0000890 store i32 %tmp2, i32* %X, !dbg !17
891 ret void, !dbg !18
Chris Lattner1811fca2004-01-05 05:06:33 +0000892}
Devang Patel4da997b2009-11-25 23:28:01 +0000893
Devang Patel7846c1e2011-02-03 00:22:17 +0000894declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
Devang Patel4da997b2009-11-25 23:28:01 +0000895
896!0 = metadata !{i32 459008, metadata !1, metadata !"X",
897 metadata !3, i32 2, metadata !6}; [ DW_TAG_auto_variable ]
898!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
899!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo", metadata !"foo",
900 metadata !"foo", metadata !3, i32 1, metadata !4,
901 i1 false, i1 true}; [DW_TAG_subprogram ]
902!3 = metadata !{i32 458769, i32 0, i32 12, metadata !"foo.c",
903 metadata !"/private/tmp", metadata !"clang 1.1", i1 true,
904 i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
905!4 = metadata !{i32 458773, metadata !3, metadata !"", null, i32 0, i64 0, i64 0,
906 i64 0, i32 0, null, metadata !5, i32 0}; [DW_TAG_subroutine_type ]
907!5 = metadata !{null}
908!6 = metadata !{i32 458788, metadata !3, metadata !"int", metadata !3, i32 0,
909 i64 32, i64 32, i64 0, i32 0, i32 5}; [DW_TAG_base_type ]
910!7 = metadata !{i32 2, i32 7, metadata !1, null}
911!8 = metadata !{i32 2, i32 3, metadata !1, null}
912!9 = metadata !{i32 459008, metadata !1, metadata !"Y", metadata !3, i32 3,
913 metadata !6}; [ DW_TAG_auto_variable ]
914!10 = metadata !{i32 3, i32 7, metadata !1, null}
915!11 = metadata !{i32 3, i32 3, metadata !1, null}
916!12 = metadata !{i32 459008, metadata !13, metadata !"Z", metadata !3, i32 5,
917 metadata !6}; [ DW_TAG_auto_variable ]
918!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
919!14 = metadata !{i32 5, i32 9, metadata !13, null}
920!15 = metadata !{i32 5, i32 5, metadata !13, null}
921!16 = metadata !{i32 6, i32 5, metadata !13, null}
922!17 = metadata !{i32 8, i32 3, metadata !1, null}
923!18 = metadata !{i32 9, i32 1, metadata !2, null}
Misha Brukmanf91d9942004-05-12 19:21:57 +0000924</pre>
Chris Lattner1811fca2004-01-05 05:06:33 +0000925</div>
926
Bill Wendling991b84e2009-12-01 00:53:11 +0000927<p>This example illustrates a few important details about LLVM debugging
928 information. In particular, it shows how the <tt>llvm.dbg.declare</tt>
929 intrinsic and location information, which are attached to an instruction,
930 are applied together to allow a debugger to analyze the relationship between
931 statements, variable definitions, and the code used to implement the
932 function.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000933
Bill Wendling991b84e2009-12-01 00:53:11 +0000934<div class="doc_code">
Bill Wendling05252352009-12-01 00:59:58 +0000935<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000936call void @llvm.dbg.declare(metadata, metadata !0), !dbg !7
Bill Wendling991b84e2009-12-01 00:53:11 +0000937</pre>
938</div>
939
940<p>The first intrinsic
Devang Patel4da997b2009-11-25 23:28:01 +0000941 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendling991b84e2009-12-01 00:53:11 +0000942 encodes debugging information for the variable <tt>X</tt>. The metadata
943 <tt>!dbg !7</tt> attached to the intrinsic provides scope information for the
944 variable <tt>X</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000945
Bill Wendling991b84e2009-12-01 00:53:11 +0000946<div class="doc_code">
947<pre>
948!7 = metadata !{i32 2, i32 7, metadata !1, null}
949!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
950!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo",
951 metadata !"foo", metadata !"foo", metadata !3, i32 1,
952 metadata !4, i1 false, i1 true}; [DW_TAG_subprogram ]
953</pre>
954</div>
955
956<p>Here <tt>!7</tt> is metadata providing location information. It has four
957 fields: line number, column number, scope, and original scope. The original
958 scope represents inline location if this instruction is inlined inside a
959 caller, and is null otherwise. In this example, scope is encoded by
Devang Patel4da997b2009-11-25 23:28:01 +0000960 <tt>!1</tt>. <tt>!1</tt> represents a lexical block inside the scope
961 <tt>!2</tt>, where <tt>!2</tt> is a
Bill Wendling991b84e2009-12-01 00:53:11 +0000962 <a href="#format_subprograms">subprogram descriptor</a>. This way the
963 location information attached to the intrinsics indicates that the
964 variable <tt>X</tt> is declared at line number 2 at a function level scope in
965 function <tt>foo</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000966
Devang Patel4da997b2009-11-25 23:28:01 +0000967<p>Now lets take another example.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000968
Bill Wendling991b84e2009-12-01 00:53:11 +0000969<div class="doc_code">
Bill Wendling05252352009-12-01 00:59:58 +0000970<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000971call void @llvm.dbg.declare(metadata, metadata !12), !dbg !14
Bill Wendling991b84e2009-12-01 00:53:11 +0000972</pre>
973</div>
974
975<p>The second intrinsic
Devang Patel4da997b2009-11-25 23:28:01 +0000976 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendling991b84e2009-12-01 00:53:11 +0000977 encodes debugging information for variable <tt>Z</tt>. The metadata
978 <tt>!dbg !14</tt> attached to the intrinsic provides scope information for
979 the variable <tt>Z</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000980
Bill Wendling991b84e2009-12-01 00:53:11 +0000981<div class="doc_code">
982<pre>
983!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
984!14 = metadata !{i32 5, i32 9, metadata !13, null}
985</pre>
986</div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000987
John Criswell2a4b0802010-03-17 15:01:50 +0000988<p>Here <tt>!14</tt> indicates that <tt>Z</tt> is declared at line number 5 and
Bill Wendling991b84e2009-12-01 00:53:11 +0000989 column number 9 inside of lexical scope <tt>!13</tt>. The lexical scope
990 itself resides inside of lexical scope <tt>!1</tt> described above.</p>
991
992<p>The scope information attached with each instruction provides a
993 straightforward way to find instructions covered by a scope.</p>
994
Bill Wendlinge9353d72009-05-17 05:52:39 +0000995</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000996
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000997</div>
998
Chris Lattner1811fca2004-01-05 05:06:33 +0000999<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001000<h2>
Chris Lattner941515c2004-01-06 05:31:32 +00001001 <a name="ccxx_frontend">C/C++ front-end specific debug information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001002</h2>
Misha Brukmancda6a9b2004-12-09 20:27:37 +00001003<!-- *********************************************************************** -->
Chris Lattner1811fca2004-01-05 05:06:33 +00001004
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001005<div>
Chris Lattner1811fca2004-01-05 05:06:33 +00001006
Misha Brukmanf91d9942004-05-12 19:21:57 +00001007<p>The C and C++ front-ends represent information about the program in a format
Bill Wendlinge9353d72009-05-17 05:52:39 +00001008 that is effectively identical
1009 to <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3.0</a> in
1010 terms of information content. This allows code generators to trivially
1011 support native debuggers by generating standard dwarf information, and
1012 contains enough information for non-dwarf targets to translate it as
1013 needed.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +00001014
Jim Laskey14edc932006-03-14 18:08:46 +00001015<p>This section describes the forms used to represent C and C++ programs. Other
Bill Wendlinge9353d72009-05-17 05:52:39 +00001016 languages could pattern themselves after this (which itself is tuned to
1017 representing programs in the same way that DWARF 3 does), or they could
1018 choose to provide completely different forms if they don't fit into the DWARF
1019 model. As support for debugging information gets added to the various LLVM
1020 source-language front-ends, the information used should be documented
1021 here.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +00001022
Jim Laskey14edc932006-03-14 18:08:46 +00001023<p>The following sections provide examples of various C/C++ constructs and the
Bill Wendlinge9353d72009-05-17 05:52:39 +00001024 debug information that would best describe those constructs.</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001025
Chris Lattner1811fca2004-01-05 05:06:33 +00001026<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001027<h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001028 <a name="ccxx_compile_units">C/C++ source file information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001029</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +00001030
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001031<div>
Chris Lattner1811fca2004-01-05 05:06:33 +00001032
Bill Wendlinge9353d72009-05-17 05:52:39 +00001033<p>Given the source files <tt>MySource.cpp</tt> and <tt>MyHeader.h</tt> located
1034 in the directory <tt>/Users/mine/sources</tt>, the following code:</p>
Chris Lattner941515c2004-01-06 05:31:32 +00001035
Bill Wendlinge9353d72009-05-17 05:52:39 +00001036<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001037<pre>
1038#include "MyHeader.h"
Chris Lattner941515c2004-01-06 05:31:32 +00001039
Jim Laskey14edc932006-03-14 18:08:46 +00001040int main(int argc, char *argv[]) {
1041 return 0;
1042}
1043</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001044</div>
Chris Lattner941515c2004-01-06 05:31:32 +00001045
Misha Brukman39dcddf2008-12-16 02:54:22 +00001046<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001047
Bill Wendlinge9353d72009-05-17 05:52:39 +00001048<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001049<pre>
1050...
1051;;
Devang Patel59445db2010-03-09 00:44:10 +00001052;; Define the compile unit for the main source file "/Users/mine/sources/MySource.cpp".
Jim Laskey14edc932006-03-14 18:08:46 +00001053;;
Devang Patel59445db2010-03-09 00:44:10 +00001054!2 = metadata !{
1055 i32 524305, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001056 i32 0, ;; Unused
1057 i32 4, ;; Language Id
1058 metadata !"MySource.cpp",
1059 metadata !"/Users/mine/sources",
1060 metadata !"4.2.1 (Based on Apple Inc. build 5649) (LLVM build 00)",
1061 i1 true, ;; Main Compile Unit
1062 i1 false, ;; Optimized compile unit
1063 metadata !"", ;; Compiler flags
1064 i32 0} ;; Runtime version
1065
Jim Laskey14edc932006-03-14 18:08:46 +00001066;;
Devang Patel59445db2010-03-09 00:44:10 +00001067;; Define the file for the file "/Users/mine/sources/MySource.cpp".
Jim Laskey14edc932006-03-14 18:08:46 +00001068;;
Devang Patel80ae3492009-08-28 23:24:31 +00001069!1 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001070 i32 524329, ;; Tag
1071 metadata !"MySource.cpp",
Devang Patel80ae3492009-08-28 23:24:31 +00001072 metadata !"/Users/mine/sources",
Devang Patel4a7904d62010-07-13 16:53:20 +00001073 metadata !2 ;; Compile unit
Devang Patel59445db2010-03-09 00:44:10 +00001074}
1075
1076;;
1077;; Define the file for the file "/Users/mine/sources/Myheader.h"
1078;;
1079!3 = metadata !{
1080 i32 524329, ;; Tag
1081 metadata !"Myheader.h"
1082 metadata !"/Users/mine/sources",
Devang Patel4a7904d62010-07-13 16:53:20 +00001083 metadata !2 ;; Compile unit
Devang Patel59445db2010-03-09 00:44:10 +00001084}
Jim Laskey14edc932006-03-14 18:08:46 +00001085
Jim Laskey14edc932006-03-14 18:08:46 +00001086...
1087</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001088</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001089
Devang Patel5bc1c4b2010-03-26 19:08:36 +00001090<p>llvm::Instruction provides easy access to metadata attached with an
1091instruction. One can extract line number information encoded in LLVM IR
1092using <tt>Instruction::getMetadata()</tt> and
1093<tt>DILocation::getLineNumber()</tt>.
1094<pre>
1095 if (MDNode *N = I->getMetadata("dbg")) { // Here I is an LLVM instruction
1096 DILocation Loc(N); // DILocation is in DebugInfo.h
1097 unsigned Line = Loc.getLineNumber();
1098 StringRef File = Loc.getFilename();
1099 StringRef Dir = Loc.getDirectory();
1100 }
1101</pre>
Chris Lattner941515c2004-01-06 05:31:32 +00001102</div>
1103
1104<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001105<h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001106 <a name="ccxx_global_variable">C/C++ global variable information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001107</h3>
Chris Lattner941515c2004-01-06 05:31:32 +00001108
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001109<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001110
Misha Brukman39dcddf2008-12-16 02:54:22 +00001111<p>Given an integer global variable declared as follows:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001112
Bill Wendlinge9353d72009-05-17 05:52:39 +00001113<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001114<pre>
1115int MyGlobal = 100;
1116</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001117</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001118
Misha Brukman39dcddf2008-12-16 02:54:22 +00001119<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001120
Bill Wendlinge9353d72009-05-17 05:52:39 +00001121<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001122<pre>
1123;;
Jim Laskey14edc932006-03-14 18:08:46 +00001124;; Define the global itself.
1125;;
1126%MyGlobal = global int 100
1127...
1128;;
Devang Patel80ae3492009-08-28 23:24:31 +00001129;; List of debug info of globals
Jim Laskey14edc932006-03-14 18:08:46 +00001130;;
Devang Patel80ae3492009-08-28 23:24:31 +00001131!llvm.dbg.gv = !{!0}
Jim Laskey14edc932006-03-14 18:08:46 +00001132
1133;;
1134;; Define the global variable descriptor. Note the reference to the global
1135;; variable anchor and the global variable itself.
1136;;
Devang Patel80ae3492009-08-28 23:24:31 +00001137!0 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001138 i32 524340, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001139 i32 0, ;; Unused
1140 metadata !1, ;; Context
1141 metadata !"MyGlobal", ;; Name
1142 metadata !"MyGlobal", ;; Display Name
1143 metadata !"MyGlobal", ;; Linkage Name
Devang Patel59445db2010-03-09 00:44:10 +00001144 metadata !3, ;; Compile Unit
Devang Patel80ae3492009-08-28 23:24:31 +00001145 i32 1, ;; Line Number
Devang Patel59445db2010-03-09 00:44:10 +00001146 metadata !4, ;; Type
Devang Patel80ae3492009-08-28 23:24:31 +00001147 i1 false, ;; Is a local variable
1148 i1 true, ;; Is this a definition
1149 i32* @MyGlobal ;; The global variable
1150}
1151
Jim Laskey14edc932006-03-14 18:08:46 +00001152;;
1153;; Define the basic type of 32 bit signed integer. Note that since int is an
1154;; intrinsic type the source file is NULL and line 0.
1155;;
Devang Patel59445db2010-03-09 00:44:10 +00001156!4 = metadata !{
1157 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001158 metadata !1, ;; Context
1159 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001160 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001161 i32 0, ;; Line number
1162 i64 32, ;; Size in Bits
1163 i64 32, ;; Align in Bits
1164 i64 0, ;; Offset in Bits
1165 i32 0, ;; Flags
1166 i32 5 ;; Encoding
1167}
Jim Laskey14edc932006-03-14 18:08:46 +00001168
Jim Laskey14edc932006-03-14 18:08:46 +00001169</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001170</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001171
Chris Lattner941515c2004-01-06 05:31:32 +00001172</div>
Chris Lattner1811fca2004-01-05 05:06:33 +00001173
Jim Laskey14edc932006-03-14 18:08:46 +00001174<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001175<h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001176 <a name="ccxx_subprogram">C/C++ function information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001177</h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001178
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001179<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001180
Misha Brukman39dcddf2008-12-16 02:54:22 +00001181<p>Given a function declared as follows:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001182
Bill Wendlinge9353d72009-05-17 05:52:39 +00001183<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001184<pre>
1185int main(int argc, char *argv[]) {
1186 return 0;
1187}
1188</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001189</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001190
Misha Brukman39dcddf2008-12-16 02:54:22 +00001191<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001192
Bill Wendlinge9353d72009-05-17 05:52:39 +00001193<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001194<pre>
1195;;
Jim Laskey14edc932006-03-14 18:08:46 +00001196;; Define the anchor for subprograms. Note that the second field of the
1197;; anchor is 46, which is the same as the tag for subprograms
1198;; (46 = DW_TAG_subprogram.)
1199;;
Devang Patel59445db2010-03-09 00:44:10 +00001200!6 = metadata !{
1201 i32 524334, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001202 i32 0, ;; Unused
1203 metadata !1, ;; Context
1204 metadata !"main", ;; Name
1205 metadata !"main", ;; Display name
1206 metadata !"main", ;; Linkage name
Devang Patel59445db2010-03-09 00:44:10 +00001207 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001208 i32 1, ;; Line number
Devang Patel59445db2010-03-09 00:44:10 +00001209 metadata !4, ;; Type
Devang Patel80ae3492009-08-28 23:24:31 +00001210 i1 false, ;; Is local
Devang Patel9f738842011-04-05 22:52:06 +00001211 i1 true, ;; Is definition
1212 i32 0, ;; Virtuality attribute, e.g. pure virtual function
1213 i32 0, ;; Index into virtual table for C++ methods
1214 i32 0, ;; Type that holds virtual table.
1215 i32 0, ;; Flags
1216 i1 false, ;; True if this function is optimized
1217 Function *, ;; Pointer to llvm::Function
1218 null ;; Function template parameters
Devang Patel80ae3492009-08-28 23:24:31 +00001219}
Jim Laskey14edc932006-03-14 18:08:46 +00001220;;
1221;; Define the subprogram itself.
1222;;
Devang Patel80ae3492009-08-28 23:24:31 +00001223define i32 @main(i32 %argc, i8** %argv) {
Jim Laskey14edc932006-03-14 18:08:46 +00001224...
1225}
1226</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001227</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001228
1229</div>
1230
1231<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001232<h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001233 <a name="ccxx_basic_types">C/C++ basic types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001234</h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001235
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001236<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001237
Misha Brukman39dcddf2008-12-16 02:54:22 +00001238<p>The following are the basic type descriptors for C/C++ core types:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001239
Jim Laskey14edc932006-03-14 18:08:46 +00001240<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001241<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001242 <a name="ccxx_basic_type_bool">bool</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001243</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001244
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001245<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001246
Bill Wendlinge9353d72009-05-17 05:52:39 +00001247<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001248<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001249!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001250 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001251 metadata !1, ;; Context
1252 metadata !"bool", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001253 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001254 i32 0, ;; Line number
1255 i64 8, ;; Size in Bits
1256 i64 8, ;; Align in Bits
1257 i64 0, ;; Offset in Bits
1258 i32 0, ;; Flags
1259 i32 2 ;; Encoding
1260}
Jim Laskey14edc932006-03-14 18:08:46 +00001261</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001262</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001263
1264</div>
1265
1266<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001267<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001268 <a name="ccxx_basic_char">char</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001269</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001271<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001272
Bill Wendlinge9353d72009-05-17 05:52:39 +00001273<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001274<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001275!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001276 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001277 metadata !1, ;; Context
1278 metadata !"char", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001279 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001280 i32 0, ;; Line number
1281 i64 8, ;; Size in Bits
1282 i64 8, ;; Align in Bits
1283 i64 0, ;; Offset in Bits
1284 i32 0, ;; Flags
1285 i32 6 ;; Encoding
1286}
Jim Laskey14edc932006-03-14 18:08:46 +00001287</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001288</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001289
1290</div>
1291
1292<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001293<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001294 <a name="ccxx_basic_unsigned_char">unsigned char</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001295</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001296
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001297<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001298
Bill Wendlinge9353d72009-05-17 05:52:39 +00001299<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001300<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001301!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001302 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001303 metadata !1, ;; Context
1304 metadata !"unsigned char",
Devang Patel59445db2010-03-09 00:44:10 +00001305 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001306 i32 0, ;; Line number
1307 i64 8, ;; Size in Bits
1308 i64 8, ;; Align in Bits
1309 i64 0, ;; Offset in Bits
1310 i32 0, ;; Flags
1311 i32 8 ;; Encoding
1312}
Jim Laskey14edc932006-03-14 18:08:46 +00001313</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001314</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001315
1316</div>
1317
1318<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001319<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001320 <a name="ccxx_basic_short">short</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001321</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001322
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001323<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001324
Bill Wendlinge9353d72009-05-17 05:52:39 +00001325<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001326<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001327!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001328 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001329 metadata !1, ;; Context
1330 metadata !"short int",
Devang Patel59445db2010-03-09 00:44:10 +00001331 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001332 i32 0, ;; Line number
1333 i64 16, ;; Size in Bits
1334 i64 16, ;; Align in Bits
1335 i64 0, ;; Offset in Bits
1336 i32 0, ;; Flags
1337 i32 5 ;; Encoding
1338}
Jim Laskey14edc932006-03-14 18:08:46 +00001339</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001340</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001341
1342</div>
1343
1344<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001345<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001346 <a name="ccxx_basic_unsigned_short">unsigned short</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001347</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001348
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001349<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001350
Bill Wendlinge9353d72009-05-17 05:52:39 +00001351<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001352<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001353!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001354 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001355 metadata !1, ;; Context
1356 metadata !"short unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +00001357 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001358 i32 0, ;; Line number
1359 i64 16, ;; Size in Bits
1360 i64 16, ;; Align in Bits
1361 i64 0, ;; Offset in Bits
1362 i32 0, ;; Flags
1363 i32 7 ;; Encoding
1364}
Jim Laskey14edc932006-03-14 18:08:46 +00001365</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001366</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001367
1368</div>
1369
1370<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001371<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001372 <a name="ccxx_basic_int">int</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001373</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001374
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001375<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001376
Bill Wendlinge9353d72009-05-17 05:52:39 +00001377<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001378<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001379!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001380 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001381 metadata !1, ;; Context
1382 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001383 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001384 i32 0, ;; Line number
1385 i64 32, ;; Size in Bits
1386 i64 32, ;; Align in Bits
1387 i64 0, ;; Offset in Bits
1388 i32 0, ;; Flags
1389 i32 5 ;; Encoding
1390}
Bill Wendlinge9353d72009-05-17 05:52:39 +00001391</pre></div>
Jim Laskey14edc932006-03-14 18:08:46 +00001392
1393</div>
1394
1395<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001396<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001397 <a name="ccxx_basic_unsigned_int">unsigned int</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001398</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001399
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001400<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001401
Bill Wendlinge9353d72009-05-17 05:52:39 +00001402<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001403<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001404!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001405 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001406 metadata !1, ;; Context
1407 metadata !"unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +00001408 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001409 i32 0, ;; Line number
1410 i64 32, ;; Size in Bits
1411 i64 32, ;; Align in Bits
1412 i64 0, ;; Offset in Bits
1413 i32 0, ;; Flags
1414 i32 7 ;; Encoding
1415}
Jim Laskey14edc932006-03-14 18:08:46 +00001416</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001417</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001418
1419</div>
1420
1421<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001422<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001423 <a name="ccxx_basic_long_long">long long</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001424</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001425
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001426<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001427
Bill Wendlinge9353d72009-05-17 05:52:39 +00001428<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001429<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001430!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001431 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001432 metadata !1, ;; Context
1433 metadata !"long long int",
Devang Patel59445db2010-03-09 00:44:10 +00001434 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001435 i32 0, ;; Line number
1436 i64 64, ;; Size in Bits
1437 i64 64, ;; Align in Bits
1438 i64 0, ;; Offset in Bits
1439 i32 0, ;; Flags
1440 i32 5 ;; Encoding
1441}
Jim Laskey14edc932006-03-14 18:08:46 +00001442</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001443</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001444
1445</div>
1446
1447<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001448<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001449 <a name="ccxx_basic_unsigned_long_long">unsigned long long</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001450</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001451
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001452<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001453
Bill Wendlinge9353d72009-05-17 05:52:39 +00001454<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001455<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001456!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001457 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001458 metadata !1, ;; Context
1459 metadata !"long long unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +00001460 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001461 i32 0, ;; Line number
1462 i64 64, ;; Size in Bits
1463 i64 64, ;; Align in Bits
1464 i64 0, ;; Offset in Bits
1465 i32 0, ;; Flags
1466 i32 7 ;; Encoding
1467}
Jim Laskey14edc932006-03-14 18:08:46 +00001468</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001469</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001470
1471</div>
1472
1473<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001474<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001475 <a name="ccxx_basic_float">float</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001476</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001477
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001478<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001479
Bill Wendlinge9353d72009-05-17 05:52:39 +00001480<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001481<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001482!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001483 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001484 metadata !1, ;; Context
1485 metadata !"float",
Devang Patel59445db2010-03-09 00:44:10 +00001486 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001487 i32 0, ;; Line number
1488 i64 32, ;; Size in Bits
1489 i64 32, ;; Align in Bits
1490 i64 0, ;; Offset in Bits
1491 i32 0, ;; Flags
1492 i32 4 ;; Encoding
1493}
Jim Laskey14edc932006-03-14 18:08:46 +00001494</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001495</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001496
1497</div>
1498
1499<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001500<h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001501 <a name="ccxx_basic_double">double</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001502</h4>
Jim Laskey14edc932006-03-14 18:08:46 +00001503
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001504<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001505
Bill Wendlinge9353d72009-05-17 05:52:39 +00001506<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001507<pre>
Devang Patel80ae3492009-08-28 23:24:31 +00001508!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001509 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001510 metadata !1, ;; Context
1511 metadata !"double",;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001512 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001513 i32 0, ;; Line number
1514 i64 64, ;; Size in Bits
1515 i64 64, ;; Align in Bits
1516 i64 0, ;; Offset in Bits
1517 i32 0, ;; Flags
1518 i32 4 ;; Encoding
1519}
Jim Laskey14edc932006-03-14 18:08:46 +00001520</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001521</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001522
1523</div>
1524
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001525</div>
1526
Jim Laskey14edc932006-03-14 18:08:46 +00001527<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001528<h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001529 <a name="ccxx_derived_types">C/C++ derived types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001530</h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001531
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001532<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001533
Misha Brukman39dcddf2008-12-16 02:54:22 +00001534<p>Given the following as an example of C/C++ derived type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001535
Bill Wendlinge9353d72009-05-17 05:52:39 +00001536<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001537<pre>
1538typedef const int *IntPtr;
1539</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001540</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001541
Misha Brukman39dcddf2008-12-16 02:54:22 +00001542<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001543
Bill Wendlinge9353d72009-05-17 05:52:39 +00001544<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001545<pre>
1546;;
1547;; Define the typedef "IntPtr".
1548;;
Devang Patel80ae3492009-08-28 23:24:31 +00001549!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001550 i32 524310, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001551 metadata !1, ;; Context
1552 metadata !"IntPtr", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001553 metadata !3, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001554 i32 0, ;; Line number
1555 i64 0, ;; Size in bits
1556 i64 0, ;; Align in bits
1557 i64 0, ;; Offset in bits
1558 i32 0, ;; Flags
1559 metadata !4 ;; Derived From type
1560}
Jim Laskey14edc932006-03-14 18:08:46 +00001561
1562;;
1563;; Define the pointer type.
1564;;
Devang Patel80ae3492009-08-28 23:24:31 +00001565!4 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001566 i32 524303, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001567 metadata !1, ;; Context
1568 metadata !"", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001569 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001570 i32 0, ;; Line number
1571 i64 64, ;; Size in bits
1572 i64 64, ;; Align in bits
1573 i64 0, ;; Offset in bits
1574 i32 0, ;; Flags
1575 metadata !5 ;; Derived From type
1576}
Jim Laskey14edc932006-03-14 18:08:46 +00001577;;
1578;; Define the const type.
1579;;
Devang Patel80ae3492009-08-28 23:24:31 +00001580!5 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001581 i32 524326, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001582 metadata !1, ;; Context
1583 metadata !"", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001584 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001585 i32 0, ;; Line number
1586 i64 32, ;; Size in bits
1587 i64 32, ;; Align in bits
1588 i64 0, ;; Offset in bits
1589 i32 0, ;; Flags
1590 metadata !6 ;; Derived From type
1591}
Jim Laskey14edc932006-03-14 18:08:46 +00001592;;
1593;; Define the int type.
1594;;
Devang Patel80ae3492009-08-28 23:24:31 +00001595!6 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001596 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001597 metadata !1, ;; Context
1598 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001599 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001600 i32 0, ;; Line number
1601 i64 32, ;; Size in bits
1602 i64 32, ;; Align in bits
1603 i64 0, ;; Offset in bits
1604 i32 0, ;; Flags
1605 5 ;; Encoding
1606}
Jim Laskey14edc932006-03-14 18:08:46 +00001607</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001608</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001609
1610</div>
1611
1612<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001613<h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001614 <a name="ccxx_composite_types">C/C++ struct/union types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001615</h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001616
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001617<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001618
Misha Brukman39dcddf2008-12-16 02:54:22 +00001619<p>Given the following as an example of C/C++ struct type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001620
Bill Wendlinge9353d72009-05-17 05:52:39 +00001621<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001622<pre>
1623struct Color {
1624 unsigned Red;
1625 unsigned Green;
1626 unsigned Blue;
1627};
1628</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001629</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001630
Misha Brukman39dcddf2008-12-16 02:54:22 +00001631<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001632
Bill Wendlinge9353d72009-05-17 05:52:39 +00001633<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001634<pre>
1635;;
1636;; Define basic type for unsigned int.
1637;;
Devang Patel80ae3492009-08-28 23:24:31 +00001638!5 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001639 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001640 metadata !1, ;; Context
1641 metadata !"unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +00001642 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001643 i32 0, ;; Line number
1644 i64 32, ;; Size in Bits
1645 i64 32, ;; Align in Bits
1646 i64 0, ;; Offset in Bits
1647 i32 0, ;; Flags
1648 i32 7 ;; Encoding
1649}
Jim Laskey14edc932006-03-14 18:08:46 +00001650;;
1651;; Define composite type for struct Color.
1652;;
Devang Patel80ae3492009-08-28 23:24:31 +00001653!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001654 i32 524307, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001655 metadata !1, ;; Context
1656 metadata !"Color", ;; Name
1657 metadata !1, ;; Compile unit
1658 i32 1, ;; Line number
1659 i64 96, ;; Size in bits
1660 i64 32, ;; Align in bits
1661 i64 0, ;; Offset in bits
1662 i32 0, ;; Flags
1663 null, ;; Derived From
1664 metadata !3, ;; Elements
1665 i32 0 ;; Runtime Language
1666}
Jim Laskey14edc932006-03-14 18:08:46 +00001667
1668;;
1669;; Define the Red field.
1670;;
Devang Patel80ae3492009-08-28 23:24:31 +00001671!4 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001672 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001673 metadata !1, ;; Context
1674 metadata !"Red", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001675 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001676 i32 2, ;; Line number
1677 i64 32, ;; Size in bits
1678 i64 32, ;; Align in bits
1679 i64 0, ;; Offset in bits
1680 i32 0, ;; Flags
1681 metadata !5 ;; Derived From type
1682}
Jim Laskey14edc932006-03-14 18:08:46 +00001683
1684;;
1685;; Define the Green field.
1686;;
Devang Patel80ae3492009-08-28 23:24:31 +00001687!6 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001688 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001689 metadata !1, ;; Context
1690 metadata !"Green", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001691 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001692 i32 3, ;; Line number
1693 i64 32, ;; Size in bits
1694 i64 32, ;; Align in bits
1695 i64 32, ;; Offset in bits
1696 i32 0, ;; Flags
1697 metadata !5 ;; Derived From type
1698}
Jim Laskey14edc932006-03-14 18:08:46 +00001699
1700;;
1701;; Define the Blue field.
1702;;
Devang Patel80ae3492009-08-28 23:24:31 +00001703!7 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001704 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001705 metadata !1, ;; Context
1706 metadata !"Blue", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001707 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001708 i32 4, ;; Line number
1709 i64 32, ;; Size in bits
1710 i64 32, ;; Align in bits
1711 i64 64, ;; Offset in bits
1712 i32 0, ;; Flags
1713 metadata !5 ;; Derived From type
1714}
Jim Laskey14edc932006-03-14 18:08:46 +00001715
1716;;
1717;; Define the array of fields used by the composite type Color.
1718;;
Devang Patel80ae3492009-08-28 23:24:31 +00001719!3 = metadata !{metadata !4, metadata !6, metadata !7}
Jim Laskey14edc932006-03-14 18:08:46 +00001720</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001721</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001722
1723</div>
1724
1725<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001726<h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001727 <a name="ccxx_enumeration_types">C/C++ enumeration types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +00001728</h3>
Jim Laskey14edc932006-03-14 18:08:46 +00001729
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001730<div>
Jim Laskey14edc932006-03-14 18:08:46 +00001731
Misha Brukman39dcddf2008-12-16 02:54:22 +00001732<p>Given the following as an example of C/C++ enumeration type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001733
Bill Wendlinge9353d72009-05-17 05:52:39 +00001734<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001735<pre>
1736enum Trees {
1737 Spruce = 100,
1738 Oak = 200,
1739 Maple = 300
1740};
1741</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001742</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001743
Misha Brukman39dcddf2008-12-16 02:54:22 +00001744<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +00001745
Bill Wendlinge9353d72009-05-17 05:52:39 +00001746<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +00001747<pre>
1748;;
1749;; Define composite type for enum Trees
1750;;
Devang Patel80ae3492009-08-28 23:24:31 +00001751!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +00001752 i32 524292, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +00001753 metadata !1, ;; Context
1754 metadata !"Trees", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +00001755 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +00001756 i32 1, ;; Line number
1757 i64 32, ;; Size in bits
1758 i64 32, ;; Align in bits
1759 i64 0, ;; Offset in bits
1760 i32 0, ;; Flags
1761 null, ;; Derived From type
1762 metadata !3, ;; Elements
1763 i32 0 ;; Runtime language
1764}
Devang Patel02aac922009-08-25 05:24:07 +00001765
Devang Patelf08e35d2009-08-26 05:01:18 +00001766;;
1767;; Define the array of enumerators used by composite type Trees.
1768;;
Devang Patel80ae3492009-08-28 23:24:31 +00001769!3 = metadata !{metadata !4, metadata !5, metadata !6}
1770
1771;;
1772;; Define Spruce enumerator.
1773;;
Devang Patel59445db2010-03-09 00:44:10 +00001774!4 = metadata !{i32 524328, metadata !"Spruce", i64 100}
Devang Patel80ae3492009-08-28 23:24:31 +00001775
1776;;
1777;; Define Oak enumerator.
1778;;
Devang Patel59445db2010-03-09 00:44:10 +00001779!5 = metadata !{i32 524328, metadata !"Oak", i64 200}
Devang Patel80ae3492009-08-28 23:24:31 +00001780
1781;;
1782;; Define Maple enumerator.
1783;;
Devang Patel59445db2010-03-09 00:44:10 +00001784!6 = metadata !{i32 524328, metadata !"Maple", i64 300}
Devang Patel80ae3492009-08-28 23:24:31 +00001785
Jim Laskey14edc932006-03-14 18:08:46 +00001786</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +00001787</div>
Jim Laskey14edc932006-03-14 18:08:46 +00001788
1789</div>
Chris Lattner1811fca2004-01-05 05:06:33 +00001790
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +00001791</div>
1792
Chris Lattner1811fca2004-01-05 05:06:33 +00001793<!-- *********************************************************************** -->
Misha Brukmanf91d9942004-05-12 19:21:57 +00001794
Chris Lattner1811fca2004-01-05 05:06:33 +00001795<hr>
Misha Brukmanf91d9942004-05-12 19:21:57 +00001796<address>
1797 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +00001798 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanf91d9942004-05-12 19:21:57 +00001799 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +00001800 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanf91d9942004-05-12 19:21:57 +00001801
1802 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +00001803 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattner1811fca2004-01-05 05:06:33 +00001804 Last modified: $Date$
Misha Brukmanf91d9942004-05-12 19:21:57 +00001805</address>
Chris Lattner1811fca2004-01-05 05:06:33 +00001806
1807</body>
1808</html>