Gitiles
Code Review Sign In
gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 5e06bb83f4d7b1b86659ad851324350afb04f5b0 / . / docs / SourceLevelDebugging.html
blob: e4566179ea2b18bde2c92f3578b432a3511a19d9 [file] [log] [blame]
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4<head>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]6 <title>Source Level Debugging with LLVM</title>
7 <link rel="stylesheet" href="llvm.css" type="text/css">
8</head>
9<body>
10
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]11<h1>Source Level Debugging with LLVM</h1>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]12
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]13<table class="layout" style="width:100%">
14 <tr class="layout">
15 <td class="left">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]16<ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]17 <li><a href="#introduction">Introduction</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]18 <ol>
19 <li><a href="#phil">Philosophy behind LLVM debugging information</a></li>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]20 <li><a href="#consumers">Debug information consumers</a></li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]21 <li><a href="#debugopt">Debugging optimized code</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]22 </ol></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]23 <li><a href="#format">Debugging information format</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]24 <ol>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]25 <li><a href="#debug_info_descriptors">Debug information descriptors</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]26 <ul>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]27 <li><a href="#format_compile_units">Compile unit descriptors</a></li>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]28 <li><a href="#format_files">File descriptors</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]29 <li><a href="#format_global_variables">Global variable descriptors</a></li>
30 <li><a href="#format_subprograms">Subprogram descriptors</a></li>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]31 <li><a href="#format_blocks">Block descriptors</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]32 <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 Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]37 <li><a href="#format_variables">Local variables</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]38 </ul></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]39 <li><a href="#format_common_intrinsics">Debugger intrinsic functions</a>
40 <ul>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]41 <li><a href="#format_common_declare">llvm.dbg.declare</a></li>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]42 <li><a href="#format_common_value">llvm.dbg.value</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]43 </ul></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]44 </ol></li>
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]45 <li><a href="#format_common_lifetime">Object lifetimes and scoping</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]46 <li><a href="#ccxx_frontend">C/C++ front-end specific debug information</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]47 <ol>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]48 <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 Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]55 </ol></li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]56</ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]57</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]58<td class="right">
Misha Brukmane849a1a2004-05-12 21:26:16 +0000[diff] [blame]59<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247"
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]60height="369">
61</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]62</tr></table>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]63
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]64<div class="doc_author">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]65 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
Jim Laskeyc760a922007-03-14 19:32:21 +0000[diff] [blame]66 and <a href="mailto:jlaskey@mac.com">Jim Laskey</a></p>
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]67</div>
68
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]69
70<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]71<h2><a name="introduction">Introduction</a></h2>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]72<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]73
74<div class="doc_text">
75
76<p>This document is the central repository for all information pertaining to
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]77 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 Lattner8ad2f982009-07-18 21:47:15 +0000[diff] [blame]80 Further, this document provides specific examples of what debug information
Chris Lattner89940752011-01-18 06:12:10 +0000[diff] [blame]81 for C/C++ looks like.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]82
83</div>
84
85<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]86<h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]87 <a name="phil">Philosophy behind LLVM debugging information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]88</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]89
90<div class="doc_text">
91
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]92<p>The idea of the LLVM debugging information is to capture how the important
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]93 pieces of the source-language's Abstract Syntax Tree map onto LLVM code.
94 Several design aspects have shaped the solution that appears here. The
95 important ones are:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]96
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]97<ul>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]98 <li>Debugging information should have very little impact on the rest of the
99 compiler. No transformations, analyses, or code generators should need to
100 be modified because of debugging information.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]101
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]102 <li>LLVM optimizations should interact in <a href="#debugopt">well-defined and
103 easily described ways</a> with the debugging information.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]104
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]105 <li>Because LLVM is designed to support arbitrary programming languages,
106 LLVM-to-LLVM tools should not need to know anything about the semantics of
107 the source-level-language.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]108
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]109 <li>Source-level languages are often <b>widely</b> different from one another.
110 LLVM should not put any restrictions of the flavor of the source-language,
111 and the debugging information should work with any language.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]112
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]113 <li>With code generator support, it should be possible to use an LLVM compiler
114 to compile a program to native machine code and standard debugging
115 formats. This allows compatibility with traditional machine-code level
116 debuggers, like GDB or DBX.</li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]117</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]118
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]119<p>The approach used by the LLVM implementation is to use a small set
120 of <a href="#format_common_intrinsics">intrinsic functions</a> to define a
121 mapping between LLVM program objects and the source-level objects. The
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]122 description of the source-level program is maintained in LLVM metadata
123 in an <a href="#ccxx_frontend">implementation-defined format</a>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]124 (the C/C++ front-end currently uses working draft 7 of
125 the <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3
126 standard</a>).</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]127
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]128<p>When a program is being debugged, a debugger interacts with the user and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]129 turns the stored debug information into source-language specific information.
130 As such, a debugger must be aware of the source-language, and is thus tied to
131 a specific language or family of languages.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]132
133</div>
134
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]135<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]136<h3>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]137 <a name="consumers">Debug information consumers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]138</h3>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]139
140<div class="doc_text">
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]141
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]142<p>The role of debug information is to provide meta information normally
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]143 stripped away during the compilation process. This meta information provides
144 an LLVM user a relationship between generated code and the original program
145 source code.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]146
Chris Lattnerc3107782010-04-05 04:11:11 +0000[diff] [blame]147<p>Currently, debug information is consumed by DwarfDebug to produce dwarf
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]148 information used by the gdb debugger. Other targets could use the same
149 information to produce stabs or other debug forms.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]150
151<p>It would also be reasonable to use debug information to feed profiling tools
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]152 for analysis of generated code, or, tools for reconstructing the original
153 source from generated code.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]154
155<p>TODO - expound a bit more.</p>
156
157</div>
158
159<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]160<h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]161 <a name="debugopt">Debugging optimized code</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]162</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]163
164<div class="doc_text">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]165
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]166<p>An extremely high priority of LLVM debugging information is to make it
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]167 interact well with optimizations and analysis. In particular, the LLVM debug
168 information provides the following guarantees:</p>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]169
170<ul>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]171 <li>LLVM debug information <b>always provides information to accurately read
172 the source-level state of the program</b>, regardless of which LLVM
173 optimizations have been run, and without any modification to the
174 optimizations themselves. However, some optimizations may impact the
175 ability to modify the current state of the program with a debugger, such
176 as setting program variables, or calling functions that have been
177 deleted.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]178
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]179 <li>LLVM optimizations gracefully interact with debugging information. If
180 they are not aware of debug information, they are automatically disabled
181 as necessary in the cases that would invalidate the debug info. This
182 retains the LLVM features, making it easy to write new
183 transformations.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]184
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]185 <li>As desired, LLVM optimizations can be upgraded to be aware of the LLVM
186 debugging information, allowing them to update the debugging information
187 as they perform aggressive optimizations. This means that, with effort,
188 the LLVM optimizers could optimize debug code just as well as non-debug
189 code.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]190
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]191 <li>LLVM debug information does not prevent many important optimizations from
192 happening (for example inlining, basic block reordering/merging/cleanup,
193 tail duplication, etc), further reducing the amount of the compiler that
194 eventually is "aware" of debugging information.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]195
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]196 <li>LLVM debug information is automatically optimized along with the rest of
197 the program, using existing facilities. For example, duplicate
198 information is automatically merged by the linker, and unused information
199 is automatically removed.</li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]200</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]201
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]202<p>Basically, the debug information allows you to compile a program with
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]203 "<tt>-O0 -g</tt>" and get full debug information, allowing you to arbitrarily
204 modify the program as it executes from a debugger. Compiling a program with
205 "<tt>-O3 -g</tt>" gives you full debug information that is always available
206 and accurate for reading (e.g., you get accurate stack traces despite tail
207 call elimination and inlining), but you might lose the ability to modify the
208 program and call functions where were optimized out of the program, or
209 inlined away completely.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]210
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]211<p><a href="TestingGuide.html#quicktestsuite">LLVM test suite</a> provides a
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]212 framework to test optimizer's handling of debugging information. It can be
213 run like this:</p>
Devang Patela5c05aa2008-11-21 19:35:57 +0000[diff] [blame]214
215<div class="doc_code">
216<pre>
217% cd llvm/projects/test-suite/MultiSource/Benchmarks # or some other level
218% make TEST=dbgopt
219</pre>
220</div>
221
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]222<p>This will test impact of debugging information on optimization passes. If
223 debugging information influences optimization passes then it will be reported
224 as a failure. See <a href="TestingGuide.html">TestingGuide</a> for more
225 information on LLVM test infrastructure and how to run various tests.</p>
Devang Patela5c05aa2008-11-21 19:35:57 +0000[diff] [blame]226
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]227</div>
228
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]229<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]230<h2>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]231 <a name="format">Debugging information format</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]232</h2>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]233<!-- *********************************************************************** -->
234
235<div class="doc_text">
236
237<p>LLVM debugging information has been carefully designed to make it possible
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]238 for the optimizer to optimize the program and debugging information without
239 necessarily having to know anything about debugging information. In
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]240 particular, the use of metadata avoids duplicated debugging information from
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]241 the beginning, and the global dead code elimination pass automatically
242 deletes debugging information for a function if it decides to delete the
243 function. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]244
245<p>To do this, most of the debugging information (descriptors for types,
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]246 variables, functions, source files, etc) is inserted by the language
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]247 front-end in the form of LLVM metadata. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]248
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]249<p>Debug information is designed to be agnostic about the target debugger and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]250 debugging information representation (e.g. DWARF/Stabs/etc). It uses a
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]251 generic pass to decode the information that represents variables, types,
252 functions, namespaces, etc: this allows for arbitrary source-language
253 semantics and type-systems to be used, as long as there is a module
254 written for the target debugger to interpret the information. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]255
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]256<p>To provide basic functionality, the LLVM debugger does have to make some
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]257 assumptions about the source-level language being debugged, though it keeps
258 these to a minimum. The only common features that the LLVM debugger assumes
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]259 exist are <a href="#format_files">source files</a>,
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]260 and <a href="#format_global_variables">program objects</a>. These abstract
261 objects are used by a debugger to form stack traces, show information about
262 local variables, etc.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]263
264<p>This section of the documentation first describes the representation aspects
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]265 common to any source-language. The <a href="#ccxx_frontend">next section</a>
266 describes the data layout conventions used by the C and C++ front-ends.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]267
268</div>
269
270<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]271<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]272 <a name="debug_info_descriptors">Debug information descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]273</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]274
275<div class="doc_text">
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]276
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]277<p>In consideration of the complexity and volume of debug information, LLVM
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]278 provides a specification for well formed debug descriptors. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]279
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]280<p>Consumers of LLVM debug information expect the descriptors for program
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]281 objects to start in a canonical format, but the descriptors can include
282 additional information appended at the end that is source-language
283 specific. All LLVM debugging information is versioned, allowing backwards
284 compatibility in the case that the core structures need to change in some
285 way. Also, all debugging information objects start with a tag to indicate
286 what type of object it is. The source-language is allowed to define its own
287 objects, by using unreserved tag numbers. We recommend using with tags in
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]288 the range 0x1000 through 0x2000 (there is a defined enum DW_TAG_user_base =
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]289 0x1000.)</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]290
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]291<p>The fields of debug descriptors used internally by LLVM
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]292 are restricted to only the simple data types <tt>i32</tt>, <tt>i1</tt>,
293 <tt>float</tt>, <tt>double</tt>, <tt>mdstring</tt> and <tt>mdnode</tt>. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]294
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]295<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]296<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]297!1 = metadata !{
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]298 i32, ;; A tag
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]299 ...
300}
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]301</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]302</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]303
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]304<p><a name="LLVMDebugVersion">The first field of a descriptor is always an
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]305 <tt>i32</tt> containing a tag value identifying the content of the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]306 descriptor. The remaining fields are specific to the descriptor. The values
307 of tags are loosely bound to the tag values of DWARF information entries.
308 However, that does not restrict the use of the information supplied to DWARF
309 targets. To facilitate versioning of debug information, the tag is augmented
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]310 with the current debug version (LLVMDebugVersion = 8 &lt;&lt; 16 or 0x80000 or
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]311 524288.)</a></p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]312
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]313<p>The details of the various descriptors follow.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]314
315</div>
316
317<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]318<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]319 <a name="format_compile_units">Compile unit descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]320</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]321
322<div class="doc_text">
323
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]324<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]325<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]326!0 = metadata !{
327 i32, ;; Tag = 17 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
328 ;; (DW_TAG_compile_unit)
329 i32, ;; Unused field.
330 i32, ;; DWARF language identifier (ex. DW_LANG_C89)
331 metadata, ;; Source file name
332 metadata, ;; Source file directory (includes trailing slash)
333 metadata ;; Producer (ex. "4.0.1 LLVM (LLVM research group)")
334 i1, ;; True if this is a main compile unit.
335 i1, ;; True if this is optimized.
336 metadata, ;; Flags
337 i32 ;; Runtime version
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]338}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]339</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]340</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]341
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]342<p>These descriptors contain a source language ID for the file (we use the DWARF
343 3.0 ID numbers, such as <tt>DW_LANG_C89</tt>, <tt>DW_LANG_C_plus_plus</tt>,
344 <tt>DW_LANG_Cobol74</tt>, etc), three strings describing the filename,
345 working directory of the compiler, and an identifier string for the compiler
346 that produced it.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]347
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]348<p>Compile unit descriptors provide the root context for objects declared in a
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]349 specific compilation unit. File descriptors are defined using this context.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]350
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]351</div>
352
353<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]354<h4>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]355 <a name="format_files">File descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]356</h4>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]357
358<div class="doc_text">
359
360<div class="doc_code">
361<pre>
362!0 = metadata !{
363 i32, ;; Tag = 41 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
364 ;; (DW_TAG_file_type)
365 metadata, ;; Source file name
366 metadata, ;; Source file directory (includes trailing slash)
367 metadata ;; Reference to compile unit where defined
368}
369</pre>
370</div>
371
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]372<p>These descriptors contain information for a file. Global variables and top
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]373 level functions would be defined using this context.k File descriptors also
374 provide context for source line correspondence. </p>
375
376<p>Each input file is encoded as a separate file descriptor in LLVM debugging
377 information output. Each file descriptor would be defined using a
378 compile unit. </p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]379
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]380</div>
381
382<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]383<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]384 <a name="format_global_variables">Global variable descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]385</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]386
387<div class="doc_text">
388
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]389<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]390<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]391!1 = metadata !{
392 i32, ;; Tag = 52 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
393 ;; (DW_TAG_variable)
394 i32, ;; Unused field.
395 metadata, ;; Reference to context descriptor
396 metadata, ;; Name
397 metadata, ;; Display name (fully qualified C++ name)
398 metadata, ;; MIPS linkage name (for C++)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]399 metadata, ;; Reference to file where defined
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]400 i32, ;; Line number where defined
401 metadata, ;; Reference to type descriptor
402 i1, ;; True if the global is local to compile unit (static)
403 i1, ;; True if the global is defined in the compile unit (not extern)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]404 {}* ;; Reference to the global variable
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]405}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]406</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]407</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]408
409<p>These descriptors provide debug information about globals variables. The
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]410provide details such as name, type and where the variable is defined. All
411global variables are collected by named metadata <tt>!llvm.dbg.gv</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]412
413</div>
414
415<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]416<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]417 <a name="format_subprograms">Subprogram descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]418</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]419
420<div class="doc_text">
421
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]422<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]423<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]424!2 = metadata !{
425 i32, ;; Tag = 46 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
426 ;; (DW_TAG_subprogram)
427 i32, ;; Unused field.
428 metadata, ;; Reference to context descriptor
429 metadata, ;; Name
430 metadata, ;; Display name (fully qualified C++ name)
431 metadata, ;; MIPS linkage name (for C++)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]432 metadata, ;; Reference to file where defined
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]433 i32, ;; Line number where defined
434 metadata, ;; Reference to type descriptor
435 i1, ;; True if the global is local to compile unit (static)
Devang Patel5e06bb82011-04-22 23:10:17 +0000[diff] [blame^]436 i1, ;; True if the global is defined in the compile unit (not extern)
437 i32, ;; Virtuality, e.g. dwarf::DW_VIRTUALITY__virtual
438 i32, ;; Index into a virtual function
Devang Patel80ecc152010-06-04 22:49:55 +0000[diff] [blame]439 metadata, ;; indicates which base type contains the vtable pointer for the
440 ;; derived class
Devang Patel5e06bb82011-04-22 23:10:17 +0000[diff] [blame^]441 i1, ;; isArtificial
442 i1, ;; isOptimized
443 Function *,;; Pointer to LLVM function
444 metadata, ;; Lists function template parameters
445 metadata ;; Function declaration descriptor
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]446}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]447</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]448</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]449
450<p>These descriptors provide debug information about functions, methods and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]451 subprograms. They provide details such as name, return types and the source
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]452 location where the subprogram is defined.
453 All subprogram descriptors are collected by a named metadata
454 <tt>!llvm.dbg.sp</tt>.
455</p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]456
457</div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]458
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]459<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]460<h4>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]461 <a name="format_blocks">Block descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]462</h4>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]463
464<div class="doc_text">
465
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]466<div class="doc_code">
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]467<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]468!3 = metadata !{
Devang Patelc79dda22010-10-04 16:51:59 +0000[diff] [blame]469 i32, ;; Tag = 11 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block)
Devang Patel7f271fc2010-10-01 22:45:00 +0000[diff] [blame]470 metadata,;; Reference to context descriptor
471 i32, ;; Line number
Devang Patel90d81f12011-03-08 16:25:29 +0000[diff] [blame]472 i32, ;; Column number
473 metadata,;; Reference to source file
474 i32 ;; Unique ID to identify blocks from a template function
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]475}
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]476</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]477</div>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]478
479<p>These descriptors provide debug information about nested blocks within a
Devang Patel7f271fc2010-10-01 22:45:00 +0000[diff] [blame]480 subprogram. The line number and column numbers are used to dinstinguish
481 two lexical blocks at same depth. </p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]482
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]483</div>
484
485<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]486<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]487 <a name="format_basic_type">Basic type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]488</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]489
490<div class="doc_text">
491
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]492<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]493<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]494!4 = metadata !{
495 i32, ;; Tag = 36 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
496 ;; (DW_TAG_base_type)
497 metadata, ;; Reference to context (typically a compile unit)
498 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]499 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]500 i32, ;; Line number where defined (may be 0)
501 i64, ;; Size in bits
502 i64, ;; Alignment in bits
503 i64, ;; Offset in bits
504 i32, ;; Flags
505 i32 ;; DWARF type encoding
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]506}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]507</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]508</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]509
510<p>These descriptors define primitive types used in the code. Example int, bool
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]511 and float. The context provides the scope of the type, which is usually the
512 top level. Since basic types are not usually user defined the compile unit
513 and line number can be left as NULL and 0. The size, alignment and offset
514 are expressed in bits and can be 64 bit values. The alignment is used to
515 round the offset when embedded in a
516 <a href="#format_composite_type">composite type</a> (example to keep float
517 doubles on 64 bit boundaries.) The offset is the bit offset if embedded in
518 a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]519
520<p>The type encoding provides the details of the type. The values are typically
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]521 one of the following:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]522
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]523<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]524<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]525DW_ATE_address = 1
526DW_ATE_boolean = 2
527DW_ATE_float = 4
528DW_ATE_signed = 5
529DW_ATE_signed_char = 6
530DW_ATE_unsigned = 7
531DW_ATE_unsigned_char = 8
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]532</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]533</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]534
535</div>
536
537<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]538<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]539 <a name="format_derived_type">Derived type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]540</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]541
542<div class="doc_text">
543
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]544<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]545<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]546!5 = metadata !{
547 i32, ;; Tag (see below)
548 metadata, ;; Reference to context
549 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]550 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]551 i32, ;; Line number where defined (may be 0)
Devang Patel0ffd10b2010-10-01 19:19:30 +0000[diff] [blame]552 i64, ;; Size in bits
553 i64, ;; Alignment in bits
554 i64, ;; Offset in bits
Devang Patele9db5e22011-04-16 00:11:51 +0000[diff] [blame]555 metadata, ;; Reference to type derived from
556 metadata, ;; (optional) Name of the Objective C property assoicated with
557 ;; Objective-C an ivar
558 metadata, ;; (optional) Name of the Objective C property getter selector.
559 metadata, ;; (optional) Name of the Objective C property setter selector.
560 i32 ;; (optional) Objective C property attributes.
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]561}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]562</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]563</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]564
565<p>These descriptors are used to define types derived from other types. The
566value of the tag varies depending on the meaning. The following are possible
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]567tag values:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]568
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]569<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]570<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]571DW_TAG_formal_parameter = 5
572DW_TAG_member = 13
573DW_TAG_pointer_type = 15
574DW_TAG_reference_type = 16
575DW_TAG_typedef = 22
576DW_TAG_const_type = 38
577DW_TAG_volatile_type = 53
578DW_TAG_restrict_type = 55
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]579</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]580</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]581
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]582<p><tt>DW_TAG_member</tt> is used to define a member of
583 a <a href="#format_composite_type">composite type</a>
584 or <a href="#format_subprograms">subprogram</a>. The type of the member is
585 the <a href="#format_derived_type">derived
586 type</a>. <tt>DW_TAG_formal_parameter</tt> is used to define a member which
587 is a formal argument of a subprogram.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]588
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]589<p><tt>DW_TAG_typedef</tt> is used to provide a name for the derived type.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]590
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]591<p><tt>DW_TAG_pointer_type</tt>,<tt>DW_TAG_reference_type</tt>,
592 <tt>DW_TAG_const_type</tt>, <tt>DW_TAG_volatile_type</tt>
593 and <tt>DW_TAG_restrict_type</tt> are used to qualify
594 the <a href="#format_derived_type">derived type</a>. </p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]595
596<p><a href="#format_derived_type">Derived type</a> location can be determined
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]597 from the compile unit and line number. The size, alignment and offset are
598 expressed in bits and can be 64 bit values. The alignment is used to round
599 the offset when embedded in a <a href="#format_composite_type">composite
600 type</a> (example to keep float doubles on 64 bit boundaries.) The offset is
601 the bit offset if embedded in a <a href="#format_composite_type">composite
602 type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]603
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]604<p>Note that the <tt>void *</tt> type is expressed as a type derived from NULL.
605</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]606
607</div>
608
609<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]610<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]611 <a name="format_composite_type">Composite type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]612</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]613
614<div class="doc_text">
615
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]616<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]617<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]618!6 = metadata !{
619 i32, ;; Tag (see below)
620 metadata, ;; Reference to context
621 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]622 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]623 i32, ;; Line number where defined (may be 0)
624 i64, ;; Size in bits
625 i64, ;; Alignment in bits
626 i64, ;; Offset in bits
627 i32, ;; Flags
628 metadata, ;; Reference to type derived from
629 metadata, ;; Reference to array of member descriptors
630 i32 ;; Runtime languages
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]631}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]632</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]633</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]634
635<p>These descriptors are used to define types that are composed of 0 or more
636elements. The value of the tag varies depending on the meaning. The following
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]637are possible tag values:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]638
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]639<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]640<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]641DW_TAG_array_type = 1
642DW_TAG_enumeration_type = 4
643DW_TAG_structure_type = 19
644DW_TAG_union_type = 23
645DW_TAG_vector_type = 259
Bruno Cardoso Lopesd80ddc02009-05-29 17:08:57 +0000[diff] [blame]646DW_TAG_subroutine_type = 21
647DW_TAG_inheritance = 28
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]648</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]649</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]650
Jim Laskeyf8a01a92006-06-15 20:51:43 +0000[diff] [blame]651<p>The vector flag indicates that an array type is a native packed vector.</p>
652
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]653<p>The members of array types (tag = <tt>DW_TAG_array_type</tt>) or vector types
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]654 (tag = <tt>DW_TAG_vector_type</tt>) are <a href="#format_subrange">subrange
655 descriptors</a>, each representing the range of subscripts at that level of
656 indexing.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]657
658<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]659 <a href="#format_enumeration">enumerator descriptors</a>, each representing
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]660 the definition of enumeration value for the set. All enumeration type
661 descriptors are collected by named metadata <tt>!llvm.dbg.enum</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]662
663<p>The members of structure (tag = <tt>DW_TAG_structure_type</tt>) or union (tag
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]664 = <tt>DW_TAG_union_type</tt>) types are any one of
665 the <a href="#format_basic_type">basic</a>,
666 <a href="#format_derived_type">derived</a>
667 or <a href="#format_composite_type">composite</a> type descriptors, each
668 representing a field member of the structure or union.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]669
Jim Laskey4a9df242006-08-21 21:21:06 +0000[diff] [blame]670<p>For C++ classes (tag = <tt>DW_TAG_structure_type</tt>), member descriptors
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]671 provide information about base classes, static members and member
672 functions. If a member is a <a href="#format_derived_type">derived type
673 descriptor</a> and has a tag of <tt>DW_TAG_inheritance</tt>, then the type
674 represents a base class. If the member of is
675 a <a href="#format_global_variables">global variable descriptor</a> then it
676 represents a static member. And, if the member is
677 a <a href="#format_subprograms">subprogram descriptor</a> then it represents
678 a member function. For static members and member
679 functions, <tt>getName()</tt> returns the members link or the C++ mangled
680 name. <tt>getDisplayName()</tt> the simplied version of the name.</p>
Jim Laskey4a9df242006-08-21 21:21:06 +0000[diff] [blame]681
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]682<p>The first member of subroutine (tag = <tt>DW_TAG_subroutine_type</tt>) type
683 elements is the return type for the subroutine. The remaining elements are
684 the formal arguments to the subroutine.</p>
Jim Laskey094ee722006-06-20 21:13:20 +0000[diff] [blame]685
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]686<p><a href="#format_composite_type">Composite type</a> location can be
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]687 determined from the compile unit and line number. The size, alignment and
688 offset are expressed in bits and can be 64 bit values. The alignment is used
689 to round the offset when embedded in
690 a <a href="#format_composite_type">composite type</a> (as an example, to keep
691 float doubles on 64 bit boundaries.) The offset is the bit offset if embedded
692 in a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]693
694</div>
695
696<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]697<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]698 <a name="format_subrange">Subrange descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]699</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]700
701<div class="doc_text">
702
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]703<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]704<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]705!42 = metadata !{
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]706 i32, ;; Tag = 33 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subrange_type)
707 i64, ;; Low value
708 i64 ;; High value
709}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]710</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]711</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]712
713<p>These descriptors are used to define ranges of array subscripts for an array
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]714 <a href="#format_composite_type">composite type</a>. The low value defines
715 the lower bounds typically zero for C/C++. The high value is the upper
716 bounds. Values are 64 bit. High - low + 1 is the size of the array. If low
Devang Patel3f932a72011-04-08 23:39:38 +0000[diff] [blame]717 > high the array bounds are not included in generated debugging information.
718</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]719
720</div>
721
722<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]723<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]724 <a name="format_enumeration">Enumerator descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]725</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]726
727<div class="doc_text">
728
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]729<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]730<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]731!6 = metadata !{
732 i32, ;; Tag = 40 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
733 ;; (DW_TAG_enumerator)
734 metadata, ;; Name
735 i64 ;; Value
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]736}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]737</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]738</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]739
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]740<p>These descriptors are used to define members of an
741 enumeration <a href="#format_composite_type">composite type</a>, it
742 associates the name to the value.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]743
744</div>
745
746<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]747<h4>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]748 <a name="format_variables">Local variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]749</h4>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]750
751<div class="doc_text">
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]752
753<div class="doc_code">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]754<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]755!7 = metadata !{
756 i32, ;; Tag (see below)
757 metadata, ;; Context
758 metadata, ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]759 metadata, ;; Reference to file where defined
Devang Patela83688f2011-03-08 16:29:40 +0000[diff] [blame]760 i32, ;; 24 bit - Line number where defined
761 ;; 8 bit - Argument number. 1 indicates 1st argument.
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]762 metadata ;; Type descriptor
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]763}
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]764</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]765</div>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]766
767<p>These descriptors are used to define variables local to a sub program. The
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]768 value of the tag depends on the usage of the variable:</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]769
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]770<div class="doc_code">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]771<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]772DW_TAG_auto_variable = 256
773DW_TAG_arg_variable = 257
774DW_TAG_return_variable = 258
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]775</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]776</div>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]777
778<p>An auto variable is any variable declared in the body of the function. An
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]779 argument variable is any variable that appears as a formal argument to the
780 function. A return variable is used to track the result of a function and
781 has no source correspondent.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]782
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame]783<p>The context is either the subprogram or block where the variable is defined.
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]784 Name the source variable name. Compile unit and line indicate where the
785 variable was defined. Type descriptor defines the declared type of the
786 variable.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]787
788</div>
789
790<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]791<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]792 <a name="format_common_intrinsics">Debugger intrinsic functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]793</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]794
795<div class="doc_text">
796
797<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]798 provide debug information at various points in generated code.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]799
800</div>
801
802<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]803<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]804 <a name="format_common_declare">llvm.dbg.declare</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]805</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]806
807<div class="doc_text">
808<pre>
Devang Patel4c7c0c62010-10-01 19:22:16 +0000[diff] [blame]809 void %<a href="#format_common_declare">llvm.dbg.declare</a>(metadata, metadata)
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]810</pre>
811
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame]812<p>This intrinsic provides information about a local element (ex. variable.) The
NAKAMURA Takumi4d6deb02011-04-09 09:51:57 +0000[diff] [blame]813 first argument is metadata holding alloca for the variable. The
Devang Patele136e502011-02-01 17:22:12 +0000[diff] [blame]814 second argument is metadata containing description of the variable. </p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]815</div>
816
817<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]818<h4>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]819 <a name="format_common_value">llvm.dbg.value</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]820</h4>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]821
822<div class="doc_text">
823<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]824 void %<a href="#format_common_value">llvm.dbg.value</a>(metadata, i64, metadata)
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]825</pre>
826
827<p>This intrinsic provides information when a user source variable is set to a
828 new value. The first argument is the new value (wrapped as metadata). The
829 second argument is the offset in the user source variable where the new value
Devang Patele136e502011-02-01 17:22:12 +0000[diff] [blame]830 is written. The third argument is metadata containing description of the
831 user source variable. </p>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]832</div>
833
834<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]835<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]836 <a name="format_common_lifetime">Object lifetimes and scoping</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]837</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]838
839<div class="doc_text">
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]840<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 Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]842 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 Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]845 concept, it is non-trivial to model in LLVM, because it has no notion of
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]846 scoping in this sense, and does not want to be tied to a language's scoping
847 rules.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]848
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]849<p>In order to handle this, the LLVM debug format uses the metadata attached to
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]850 llvm instructions to encode line number and scoping information. Consider
851 the following C fragment, for example:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]852
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]853<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]854<pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8551. void foo() {
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8562. int X = 21;
8573. int Y = 22;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8584. {
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8595. int Z = 23;
8606. Z = X;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8617. }
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8628. X = Y;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8639. }
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]864</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]865</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]866
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]867<p>Compiled to LLVM, this function would be represented like this:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]868
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]869<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]870<pre>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]871define void @foo() nounwind ssp {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]872entry:
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]873 %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 Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]876 %0 = bitcast i32* %X to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]877 call void @llvm.dbg.declare(metadata !{i32 * %X}, metadata !0), !dbg !7
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]878 store i32 21, i32* %X, !dbg !8
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]879 %1 = bitcast i32* %Y to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]880 call void @llvm.dbg.declare(metadata !{i32 * %Y}, metadata !9), !dbg !10
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]881 store i32 22, i32* %Y, !dbg !11
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]882 %2 = bitcast i32* %Z to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]883 call void @llvm.dbg.declare(metadata !{i32 * %Z}, metadata !12), !dbg !14
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]884 store i32 23, i32* %Z, !dbg !15
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]885 %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 Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]888 store i32 %add, i32* %Z, !dbg !16
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]889 %tmp2 = load i32* %Y, !dbg !17 ; &lt;i32&gt; [#uses=1]
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]890 store i32 %tmp2, i32* %X, !dbg !17
891 ret void, !dbg !18
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]892}
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]893
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]894declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]895
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 Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]924</pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]925</div>
926
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]927<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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]933
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]934<div class="doc_code">
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]935<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]936call void @llvm.dbg.declare(metadata, metadata !0), !dbg !7
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]937</pre>
938</div>
939
940<p>The first intrinsic
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]941 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]942 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 Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]945
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]946<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 Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]960 <tt>!1</tt>. <tt>!1</tt> represents a lexical block inside the scope
961 <tt>!2</tt>, where <tt>!2</tt> is a
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]962 <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 Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]966
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]967<p>Now lets take another example.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]968
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]969<div class="doc_code">
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]970<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]971call void @llvm.dbg.declare(metadata, metadata !12), !dbg !14
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]972</pre>
973</div>
974
975<p>The second intrinsic
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]976 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]977 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 Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]980
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]981<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 Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]987
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]988<p>Here <tt>!14</tt> indicates that <tt>Z</tt> is declared at line number 5 and
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]989 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 Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]995</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]996
997<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]998<h2>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]999 <a name="ccxx_frontend">C/C++ front-end specific debug information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1000</h2>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]1001<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1002
1003<div class="doc_text">
1004
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1005<p>The C and C++ front-ends represent information about the program in a format
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1006 that is effectively identical
1007 to <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3.0</a> in
1008 terms of information content. This allows code generators to trivially
1009 support native debuggers by generating standard dwarf information, and
1010 contains enough information for non-dwarf targets to translate it as
1011 needed.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1012
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1013<p>This section describes the forms used to represent C and C++ programs. Other
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1014 languages could pattern themselves after this (which itself is tuned to
1015 representing programs in the same way that DWARF 3 does), or they could
1016 choose to provide completely different forms if they don't fit into the DWARF
1017 model. As support for debugging information gets added to the various LLVM
1018 source-language front-ends, the information used should be documented
1019 here.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1020
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1021<p>The following sections provide examples of various C/C++ constructs and the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1022 debug information that would best describe those constructs.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1023
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1024</div>
1025
1026<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1027<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1028 <a name="ccxx_compile_units">C/C++ source file information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1029</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1030
1031<div class="doc_text">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1032
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1033<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 Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1035
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1036<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1037<pre>
1038#include "MyHeader.h"
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1039
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1040int main(int argc, char *argv[]) {
1041 return 0;
1042}
1043</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1044</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1045
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1046<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1047
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1048<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1049<pre>
1050...
1051;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1052;; Define the compile unit for the main source file "/Users/mine/sources/MySource.cpp".
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1053;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1054!2 = metadata !{
1055 i32 524305, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1056 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1066;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1067;; Define the file for the file "/Users/mine/sources/MySource.cpp".
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1068;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1069!1 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1070 i32 524329, ;; Tag
1071 metadata !"MySource.cpp",
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1072 metadata !"/Users/mine/sources",
Devang Patel9fea9c22010-07-13 16:53:20 +0000[diff] [blame]1073 metadata !2 ;; Compile unit
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1074}
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 Patel9fea9c22010-07-13 16:53:20 +0000[diff] [blame]1083 metadata !2 ;; Compile unit
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1084}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1085
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1086...
1087</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1088</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1089
Devang Pateld98ec5f2010-03-26 19:08:36 +0000[diff] [blame]1090<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 Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1102</div>
1103
1104<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1105<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1106 <a name="ccxx_global_variable">C/C++ global variable information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1107</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1108
1109<div class="doc_text">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1110
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1111<p>Given an integer global variable declared as follows:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1112
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1113<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1114<pre>
1115int MyGlobal = 100;
1116</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1117</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1118
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1119<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1120
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1121<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1122<pre>
1123;;
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1124;; Define the global itself.
1125;;
1126%MyGlobal = global int 100
1127...
1128;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1129;; List of debug info of globals
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1130;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1131!llvm.dbg.gv = !{!0}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1132
1133;;
1134;; Define the global variable descriptor. Note the reference to the global
1135;; variable anchor and the global variable itself.
1136;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1137!0 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1138 i32 524340, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1139 i32 0, ;; Unused
1140 metadata !1, ;; Context
1141 metadata !"MyGlobal", ;; Name
1142 metadata !"MyGlobal", ;; Display Name
1143 metadata !"MyGlobal", ;; Linkage Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1144 metadata !3, ;; Compile Unit
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1145 i32 1, ;; Line Number
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1146 metadata !4, ;; Type
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1147 i1 false, ;; Is a local variable
1148 i1 true, ;; Is this a definition
1149 i32* @MyGlobal ;; The global variable
1150}
1151
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1152;;
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 Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1156!4 = metadata !{
1157 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1158 metadata !1, ;; Context
1159 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1160 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1161 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1168
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1169</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1170</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1171
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1172</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1173
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1174<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1175<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1176 <a name="ccxx_subprogram">C/C++ function information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1177</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1178
1179<div class="doc_text">
1180
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1181<p>Given a function declared as follows:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1182
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1183<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1184<pre>
1185int main(int argc, char *argv[]) {
1186 return 0;
1187}
1188</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1189</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1190
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1191<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1192
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1193<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1194<pre>
1195;;
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1196;; 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 Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1200!6 = metadata !{
1201 i32 524334, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1202 i32 0, ;; Unused
1203 metadata !1, ;; Context
1204 metadata !"main", ;; Name
1205 metadata !"main", ;; Display name
1206 metadata !"main", ;; Linkage name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1207 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1208 i32 1, ;; Line number
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1209 metadata !4, ;; Type
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1210 i1 false, ;; Is local
Devang Patelda194752011-04-05 22:52:06 +0000[diff] [blame]1211 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 Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1219}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1220;;
1221;; Define the subprogram itself.
1222;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1223define i32 @main(i32 %argc, i8** %argv) {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1224...
1225}
1226</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1227</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1228
1229</div>
1230
1231<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1232<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1233 <a name="ccxx_basic_types">C/C++ basic types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1234</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1235
1236<div class="doc_text">
1237
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1238<p>The following are the basic type descriptors for C/C++ core types:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1239
1240</div>
1241
1242<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1243<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1244 <a name="ccxx_basic_type_bool">bool</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1245</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1246
1247<div class="doc_text">
1248
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1249<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1250<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1251!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1252 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1253 metadata !1, ;; Context
1254 metadata !"bool", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1255 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1256 i32 0, ;; Line number
1257 i64 8, ;; Size in Bits
1258 i64 8, ;; Align in Bits
1259 i64 0, ;; Offset in Bits
1260 i32 0, ;; Flags
1261 i32 2 ;; Encoding
1262}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1263</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1264</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1265
1266</div>
1267
1268<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1269<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1270 <a name="ccxx_basic_char">char</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1271</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1272
1273<div class="doc_text">
1274
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1275<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1276<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1277!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1278 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1279 metadata !1, ;; Context
1280 metadata !"char", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1281 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1282 i32 0, ;; Line number
1283 i64 8, ;; Size in Bits
1284 i64 8, ;; Align in Bits
1285 i64 0, ;; Offset in Bits
1286 i32 0, ;; Flags
1287 i32 6 ;; Encoding
1288}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1289</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1290</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1291
1292</div>
1293
1294<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1295<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1296 <a name="ccxx_basic_unsigned_char">unsigned char</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1297</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1298
1299<div class="doc_text">
1300
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1301<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1302<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1303!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1304 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1305 metadata !1, ;; Context
1306 metadata !"unsigned char",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1307 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1308 i32 0, ;; Line number
1309 i64 8, ;; Size in Bits
1310 i64 8, ;; Align in Bits
1311 i64 0, ;; Offset in Bits
1312 i32 0, ;; Flags
1313 i32 8 ;; Encoding
1314}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1315</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1316</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1317
1318</div>
1319
1320<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1321<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1322 <a name="ccxx_basic_short">short</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1323</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1324
1325<div class="doc_text">
1326
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1327<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1328<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1329!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1330 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1331 metadata !1, ;; Context
1332 metadata !"short int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1333 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1334 i32 0, ;; Line number
1335 i64 16, ;; Size in Bits
1336 i64 16, ;; Align in Bits
1337 i64 0, ;; Offset in Bits
1338 i32 0, ;; Flags
1339 i32 5 ;; Encoding
1340}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1341</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1342</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1343
1344</div>
1345
1346<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1347<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1348 <a name="ccxx_basic_unsigned_short">unsigned short</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1349</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1350
1351<div class="doc_text">
1352
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1353<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1354<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1355!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1356 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1357 metadata !1, ;; Context
1358 metadata !"short unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1359 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1360 i32 0, ;; Line number
1361 i64 16, ;; Size in Bits
1362 i64 16, ;; Align in Bits
1363 i64 0, ;; Offset in Bits
1364 i32 0, ;; Flags
1365 i32 7 ;; Encoding
1366}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1367</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1368</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1369
1370</div>
1371
1372<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1373<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1374 <a name="ccxx_basic_int">int</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1375</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1376
1377<div class="doc_text">
1378
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1379<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1380<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1381!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1382 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1383 metadata !1, ;; Context
1384 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1385 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1386 i32 0, ;; Line number
1387 i64 32, ;; Size in Bits
1388 i64 32, ;; Align in Bits
1389 i64 0, ;; Offset in Bits
1390 i32 0, ;; Flags
1391 i32 5 ;; Encoding
1392}
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1393</pre></div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1394
1395</div>
1396
1397<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1398<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1399 <a name="ccxx_basic_unsigned_int">unsigned int</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1400</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1401
1402<div class="doc_text">
1403
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1404<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1405<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1406!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1407 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1408 metadata !1, ;; Context
1409 metadata !"unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1410 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1411 i32 0, ;; Line number
1412 i64 32, ;; Size in Bits
1413 i64 32, ;; Align in Bits
1414 i64 0, ;; Offset in Bits
1415 i32 0, ;; Flags
1416 i32 7 ;; Encoding
1417}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1418</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1419</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1420
1421</div>
1422
1423<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1424<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1425 <a name="ccxx_basic_long_long">long long</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1426</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1427
1428<div class="doc_text">
1429
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1430<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1431<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1432!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1433 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1434 metadata !1, ;; Context
1435 metadata !"long long int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1436 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1437 i32 0, ;; Line number
1438 i64 64, ;; Size in Bits
1439 i64 64, ;; Align in Bits
1440 i64 0, ;; Offset in Bits
1441 i32 0, ;; Flags
1442 i32 5 ;; Encoding
1443}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1444</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1445</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1446
1447</div>
1448
1449<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1450<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1451 <a name="ccxx_basic_unsigned_long_long">unsigned long long</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1452</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1453
1454<div class="doc_text">
1455
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1456<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1457<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1458!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1459 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1460 metadata !1, ;; Context
1461 metadata !"long long unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1462 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1463 i32 0, ;; Line number
1464 i64 64, ;; Size in Bits
1465 i64 64, ;; Align in Bits
1466 i64 0, ;; Offset in Bits
1467 i32 0, ;; Flags
1468 i32 7 ;; Encoding
1469}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1470</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1471</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1472
1473</div>
1474
1475<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1476<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1477 <a name="ccxx_basic_float">float</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1478</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1479
1480<div class="doc_text">
1481
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1482<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1483<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1484!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1485 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1486 metadata !1, ;; Context
1487 metadata !"float",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1488 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1489 i32 0, ;; Line number
1490 i64 32, ;; Size in Bits
1491 i64 32, ;; Align in Bits
1492 i64 0, ;; Offset in Bits
1493 i32 0, ;; Flags
1494 i32 4 ;; Encoding
1495}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1496</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1497</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1498
1499</div>
1500
1501<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1502<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1503 <a name="ccxx_basic_double">double</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1504</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1505
1506<div class="doc_text">
1507
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1508<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1509<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1510!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1511 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1512 metadata !1, ;; Context
1513 metadata !"double",;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1514 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1515 i32 0, ;; Line number
1516 i64 64, ;; Size in Bits
1517 i64 64, ;; Align in Bits
1518 i64 0, ;; Offset in Bits
1519 i32 0, ;; Flags
1520 i32 4 ;; Encoding
1521}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1522</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1523</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1524
1525</div>
1526
1527<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1528<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1529 <a name="ccxx_derived_types">C/C++ derived types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1530</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1531
1532<div class="doc_text">
1533
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1534<p>Given the following as an example of C/C++ derived type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1535
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1536<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1537<pre>
1538typedef const int *IntPtr;
1539</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1540</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1541
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1542<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1543
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1544<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1545<pre>
1546;;
1547;; Define the typedef "IntPtr".
1548;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1549!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1550 i32 524310, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1551 metadata !1, ;; Context
1552 metadata !"IntPtr", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1553 metadata !3, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1554 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1561
1562;;
1563;; Define the pointer type.
1564;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1565!4 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1566 i32 524303, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1567 metadata !1, ;; Context
1568 metadata !"", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1569 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1570 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1577;;
1578;; Define the const type.
1579;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1580!5 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1581 i32 524326, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1582 metadata !1, ;; Context
1583 metadata !"", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1584 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1585 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1592;;
1593;; Define the int type.
1594;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1595!6 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1596 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1597 metadata !1, ;; Context
1598 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1599 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1600 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1607</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1608</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1609
1610</div>
1611
1612<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1613<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1614 <a name="ccxx_composite_types">C/C++ struct/union types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1615</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1616
1617<div class="doc_text">
1618
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1619<p>Given the following as an example of C/C++ struct type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1620
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1621<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1622<pre>
1623struct Color {
1624 unsigned Red;
1625 unsigned Green;
1626 unsigned Blue;
1627};
1628</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1629</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1630
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1631<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1632
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1633<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1634<pre>
1635;;
1636;; Define basic type for unsigned int.
1637;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1638!5 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1639 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1640 metadata !1, ;; Context
1641 metadata !"unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1642 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1643 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1650;;
1651;; Define composite type for struct Color.
1652;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1653!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1654 i32 524307, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1655 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1667
1668;;
1669;; Define the Red field.
1670;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1671!4 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1672 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1673 metadata !1, ;; Context
1674 metadata !"Red", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1675 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1676 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1683
1684;;
1685;; Define the Green field.
1686;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1687!6 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1688 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1689 metadata !1, ;; Context
1690 metadata !"Green", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1691 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1692 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1699
1700;;
1701;; Define the Blue field.
1702;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1703!7 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1704 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1705 metadata !1, ;; Context
1706 metadata !"Blue", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1707 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1708 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1715
1716;;
1717;; Define the array of fields used by the composite type Color.
1718;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1719!3 = metadata !{metadata !4, metadata !6, metadata !7}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1720</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1721</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1722
1723</div>
1724
1725<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1726<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1727 <a name="ccxx_enumeration_types">C/C++ enumeration types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1728</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1729
1730<div class="doc_text">
1731
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1732<p>Given the following as an example of C/C++ enumeration type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1733
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1734<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1735<pre>
1736enum Trees {
1737 Spruce = 100,
1738 Oak = 200,
1739 Maple = 300
1740};
1741</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1742</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1743
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1744<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1745
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1746<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1747<pre>
1748;;
1749;; Define composite type for enum Trees
1750;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1751!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1752 i32 524292, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1753 metadata !1, ;; Context
1754 metadata !"Trees", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1755 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1756 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 Patel2a610c72009-08-25 05:24:07 +0000[diff] [blame]1765
Devang Patel82459882009-08-26 05:01:18 +0000[diff] [blame]1766;;
1767;; Define the array of enumerators used by composite type Trees.
1768;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1769!3 = metadata !{metadata !4, metadata !5, metadata !6}
1770
1771;;
1772;; Define Spruce enumerator.
1773;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1774!4 = metadata !{i32 524328, metadata !"Spruce", i64 100}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1775
1776;;
1777;; Define Oak enumerator.
1778;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1779!5 = metadata !{i32 524328, metadata !"Oak", i64 200}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1780
1781;;
1782;; Define Maple enumerator.
1783;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1784!6 = metadata !{i32 524328, metadata !"Maple", i64 300}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1785
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1786</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1787</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1788
1789</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1790
1791<!-- *********************************************************************** -->
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1792
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1793<hr>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1794<address>
1795 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1796 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1797 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1798 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1799
1800 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]1801 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1802 Last modified: $Date$
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1803</address>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1804
1805</body>
1806</html>