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Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]6 <title>Source Level Debugging with LLVM</title>
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10
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]11<h1>Source Level Debugging with LLVM</h1>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]12
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]13<table class="layout" style="width:100%">
14 <tr class="layout">
15 <td class="left">
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]16<ul>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]17 <li><a href="#introduction">Introduction</a>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]18 <ol>
19 <li><a href="#phil">Philosophy behind LLVM debugging information</a></li>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]20 <li><a href="#consumers">Debug information consumers</a></li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]21 <li><a href="#debugopt">Debugging optimized code</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]22 </ol></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]23 <li><a href="#format">Debugging information format</a>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]24 <ol>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]25 <li><a href="#debug_info_descriptors">Debug information descriptors</a>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]26 <ul>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]27 <li><a href="#format_compile_units">Compile unit descriptors</a></li>
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]28 <li><a href="#format_files">File descriptors</a></li>
Jim Laskey14edc932006-03-14 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 Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]31 <li><a href="#format_blocks">Block descriptors</a></li>
Jim Laskey14edc932006-03-14 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 Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]37 <li><a href="#format_variables">Local variables</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]38 </ul></li>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]39 <li><a href="#format_common_intrinsics">Debugger intrinsic functions</a>
40 <ul>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]41 <li><a href="#format_common_declare">llvm.dbg.declare</a></li>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]42 <li><a href="#format_common_value">llvm.dbg.value</a></li>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]43 </ul></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]44 </ol></li>
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]45 <li><a href="#format_common_lifetime">Object lifetimes and scoping</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]46 <li><a href="#ccxx_frontend">C/C++ front-end specific debug information</a>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]47 <ol>
Jim Laskey14edc932006-03-14 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 Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]55 </ol></li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]56</ul>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]57</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]58<td class="right">
Misha Brukman3c1f8e72004-05-12 21:26:16 +0000[diff] [blame]59<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247"
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]60height="369">
61</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]62</tr></table>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]63
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]64<div class="doc_author">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]65 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
Jim Laskey6e8a2f42007-03-14 19:32:21 +0000[diff] [blame]66 and <a href="mailto:jlaskey@mac.com">Jim Laskey</a></p>
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]67</div>
68
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]69
70<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]71<h2><a name="introduction">Introduction</a></h2>
Misha Brukmancda6a9b2004-12-09 20:27:37 +0000[diff] [blame]72<!-- *********************************************************************** -->
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]73
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]74<div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]75
76<p>This document is the central repository for all information pertaining to
Bill Wendlinge9353d72009-05-17 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 Lattnercb3f64f2009-07-18 21:47:15 +0000[diff] [blame]80 Further, this document provides specific examples of what debug information
Chris Lattner92ec3d12011-01-18 06:12:10 +0000[diff] [blame]81 for C/C++ looks like.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]82
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]83<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]84<h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]85 <a name="phil">Philosophy behind LLVM debugging information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]86</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]87
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]88<div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]89
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]90<p>The idea of the LLVM debugging information is to capture how the important
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]91 pieces of the source-language's Abstract Syntax Tree map onto LLVM code.
92 Several design aspects have shaped the solution that appears here. The
93 important ones are:</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]94
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]95<ul>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]96 <li>Debugging information should have very little impact on the rest of the
97 compiler. No transformations, analyses, or code generators should need to
98 be modified because of debugging information.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]99
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]100 <li>LLVM optimizations should interact in <a href="#debugopt">well-defined and
101 easily described ways</a> with the debugging information.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]102
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]103 <li>Because LLVM is designed to support arbitrary programming languages,
104 LLVM-to-LLVM tools should not need to know anything about the semantics of
105 the source-level-language.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]106
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]107 <li>Source-level languages are often <b>widely</b> different from one another.
108 LLVM should not put any restrictions of the flavor of the source-language,
109 and the debugging information should work with any language.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]110
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]111 <li>With code generator support, it should be possible to use an LLVM compiler
112 to compile a program to native machine code and standard debugging
113 formats. This allows compatibility with traditional machine-code level
114 debuggers, like GDB or DBX.</li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]115</ul>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]116
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]117<p>The approach used by the LLVM implementation is to use a small set
118 of <a href="#format_common_intrinsics">intrinsic functions</a> to define a
119 mapping between LLVM program objects and the source-level objects. The
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]120 description of the source-level program is maintained in LLVM metadata
121 in an <a href="#ccxx_frontend">implementation-defined format</a>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]122 (the C/C++ front-end currently uses working draft 7 of
123 the <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3
124 standard</a>).</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]125
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]126<p>When a program is being debugged, a debugger interacts with the user and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]127 turns the stored debug information into source-language specific information.
128 As such, a debugger must be aware of the source-language, and is thus tied to
129 a specific language or family of languages.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]130
131</div>
132
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]133<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]134<h3>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]135 <a name="consumers">Debug information consumers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]136</h3>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]137
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]138<div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]139
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]140<p>The role of debug information is to provide meta information normally
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]141 stripped away during the compilation process. This meta information provides
142 an LLVM user a relationship between generated code and the original program
143 source code.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]144
Chris Lattner904f2172010-04-05 04:11:11 +0000[diff] [blame]145<p>Currently, debug information is consumed by DwarfDebug to produce dwarf
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]146 information used by the gdb debugger. Other targets could use the same
147 information to produce stabs or other debug forms.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]148
149<p>It would also be reasonable to use debug information to feed profiling tools
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]150 for analysis of generated code, or, tools for reconstructing the original
151 source from generated code.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]152
153<p>TODO - expound a bit more.</p>
154
155</div>
156
157<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]158<h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]159 <a name="debugopt">Debugging optimized code</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]160</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]161
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]162<div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]163
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]164<p>An extremely high priority of LLVM debugging information is to make it
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]165 interact well with optimizations and analysis. In particular, the LLVM debug
166 information provides the following guarantees:</p>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]167
168<ul>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]169 <li>LLVM debug information <b>always provides information to accurately read
170 the source-level state of the program</b>, regardless of which LLVM
171 optimizations have been run, and without any modification to the
172 optimizations themselves. However, some optimizations may impact the
173 ability to modify the current state of the program with a debugger, such
174 as setting program variables, or calling functions that have been
175 deleted.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]176
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]177 <li>As desired, LLVM optimizations can be upgraded to be aware of the LLVM
178 debugging information, allowing them to update the debugging information
179 as they perform aggressive optimizations. This means that, with effort,
180 the LLVM optimizers could optimize debug code just as well as non-debug
181 code.</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]182
Devang Patel5c26a852011-05-31 17:45:27 +0000[diff] [blame]183 <li>LLVM debug information does not prevent optimizations from
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]184 happening (for example inlining, basic block reordering/merging/cleanup,
Devang Patel1d81ea82011-05-31 18:06:14 +0000[diff] [blame]185 tail duplication, etc).</li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]186
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]187 <li>LLVM debug information is automatically optimized along with the rest of
188 the program, using existing facilities. For example, duplicate
189 information is automatically merged by the linker, and unused information
190 is automatically removed.</li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]191</ul>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]192
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]193<p>Basically, the debug information allows you to compile a program with
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]194 "<tt>-O0 -g</tt>" and get full debug information, allowing you to arbitrarily
195 modify the program as it executes from a debugger. Compiling a program with
196 "<tt>-O3 -g</tt>" gives you full debug information that is always available
197 and accurate for reading (e.g., you get accurate stack traces despite tail
198 call elimination and inlining), but you might lose the ability to modify the
199 program and call functions where were optimized out of the program, or
200 inlined away completely.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]201
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]202<p><a href="TestingGuide.html#quicktestsuite">LLVM test suite</a> provides a
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]203 framework to test optimizer's handling of debugging information. It can be
204 run like this:</p>
Devang Patelb885a912008-11-21 19:35:57 +0000[diff] [blame]205
206<div class="doc_code">
207<pre>
208% cd llvm/projects/test-suite/MultiSource/Benchmarks # or some other level
209% make TEST=dbgopt
210</pre>
211</div>
212
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]213<p>This will test impact of debugging information on optimization passes. If
214 debugging information influences optimization passes then it will be reported
215 as a failure. See <a href="TestingGuide.html">TestingGuide</a> for more
216 information on LLVM test infrastructure and how to run various tests.</p>
Devang Patelb885a912008-11-21 19:35:57 +0000[diff] [blame]217
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]218</div>
219
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]220</div>
221
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]222<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]223<h2>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]224 <a name="format">Debugging information format</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]225</h2>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]226<!-- *********************************************************************** -->
227
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]228<div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]229
230<p>LLVM debugging information has been carefully designed to make it possible
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]231 for the optimizer to optimize the program and debugging information without
232 necessarily having to know anything about debugging information. In
John Criswell2a4b0802010-03-17 15:01:50 +0000[diff] [blame]233 particular, the use of metadata avoids duplicated debugging information from
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]234 the beginning, and the global dead code elimination pass automatically
235 deletes debugging information for a function if it decides to delete the
236 function. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]237
238<p>To do this, most of the debugging information (descriptors for types,
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]239 variables, functions, source files, etc) is inserted by the language
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]240 front-end in the form of LLVM metadata. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]241
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]242<p>Debug information is designed to be agnostic about the target debugger and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]243 debugging information representation (e.g. DWARF/Stabs/etc). It uses a
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]244 generic pass to decode the information that represents variables, types,
245 functions, namespaces, etc: this allows for arbitrary source-language
246 semantics and type-systems to be used, as long as there is a module
247 written for the target debugger to interpret the information. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]248
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]249<p>To provide basic functionality, the LLVM debugger does have to make some
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]250 assumptions about the source-level language being debugged, though it keeps
251 these to a minimum. The only common features that the LLVM debugger assumes
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]252 exist are <a href="#format_files">source files</a>,
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]253 and <a href="#format_global_variables">program objects</a>. These abstract
254 objects are used by a debugger to form stack traces, show information about
255 local variables, etc.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]256
257<p>This section of the documentation first describes the representation aspects
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]258 common to any source-language. The <a href="#ccxx_frontend">next section</a>
259 describes the data layout conventions used by the C and C++ front-ends.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]260
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]261<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]262<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]263 <a name="debug_info_descriptors">Debug information descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]264</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]265
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]266<div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]267
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]268<p>In consideration of the complexity and volume of debug information, LLVM
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]269 provides a specification for well formed debug descriptors. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]270
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]271<p>Consumers of LLVM debug information expect the descriptors for program
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]272 objects to start in a canonical format, but the descriptors can include
273 additional information appended at the end that is source-language
274 specific. All LLVM debugging information is versioned, allowing backwards
275 compatibility in the case that the core structures need to change in some
276 way. Also, all debugging information objects start with a tag to indicate
277 what type of object it is. The source-language is allowed to define its own
278 objects, by using unreserved tag numbers. We recommend using with tags in
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]279 the range 0x1000 through 0x2000 (there is a defined enum DW_TAG_user_base =
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]280 0x1000.)</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]281
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]282<p>The fields of debug descriptors used internally by LLVM
Nick Lewyckya87014f2010-03-31 07:50:17 +0000[diff] [blame]283 are restricted to only the simple data types <tt>i32</tt>, <tt>i1</tt>,
284 <tt>float</tt>, <tt>double</tt>, <tt>mdstring</tt> and <tt>mdnode</tt>. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]285
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]286<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]287<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]288!1 = metadata !{
Nick Lewyckya87014f2010-03-31 07:50:17 +0000[diff] [blame]289 i32, ;; A tag
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]290 ...
291}
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]292</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]293</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]294
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000[diff] [blame]295<p><a name="LLVMDebugVersion">The first field of a descriptor is always an
Nick Lewyckya87014f2010-03-31 07:50:17 +0000[diff] [blame]296 <tt>i32</tt> containing a tag value identifying the content of the
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]297 descriptor. The remaining fields are specific to the descriptor. The values
298 of tags are loosely bound to the tag values of DWARF information entries.
299 However, that does not restrict the use of the information supplied to DWARF
300 targets. To facilitate versioning of debug information, the tag is augmented
Nick Lewyckyf6e37112011-07-25 21:13:23 +0000[diff] [blame^]301 with the current debug version (LLVMDebugVersion = 8 &lt;&lt; 16 or
302 0x80000 or 524288.)</a></p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]303
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000[diff] [blame]304<p>The details of the various descriptors follow.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]305
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]306<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]307<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]308 <a name="format_compile_units">Compile unit descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]309</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]310
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]311<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]312
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]313<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]314<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]315!0 = metadata !{
316 i32, ;; Tag = 17 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
317 ;; (DW_TAG_compile_unit)
318 i32, ;; Unused field.
319 i32, ;; DWARF language identifier (ex. DW_LANG_C89)
320 metadata, ;; Source file name
321 metadata, ;; Source file directory (includes trailing slash)
322 metadata ;; Producer (ex. "4.0.1 LLVM (LLVM research group)")
323 i1, ;; True if this is a main compile unit.
324 i1, ;; True if this is optimized.
325 metadata, ;; Flags
326 i32 ;; Runtime version
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]327}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]328</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]329</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]330
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]331<p>These descriptors contain a source language ID for the file (we use the DWARF
332 3.0 ID numbers, such as <tt>DW_LANG_C89</tt>, <tt>DW_LANG_C_plus_plus</tt>,
333 <tt>DW_LANG_Cobol74</tt>, etc), three strings describing the filename,
334 working directory of the compiler, and an identifier string for the compiler
335 that produced it.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]336
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]337<p>Compile unit descriptors provide the root context for objects declared in a
Devang Patel09fa69e2011-05-03 16:18:28 +0000[diff] [blame]338 specific compilation unit. File descriptors are defined using this context.
339 These descriptors are collected by a named metadata
340 <tt>!llvm.dbg.cu</tt>.
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]341
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]342</div>
343
344<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]345<h4>
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]346 <a name="format_files">File descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]347</h4>
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]348
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]349<div>
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]350
351<div class="doc_code">
352<pre>
353!0 = metadata !{
354 i32, ;; Tag = 41 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
355 ;; (DW_TAG_file_type)
356 metadata, ;; Source file name
357 metadata, ;; Source file directory (includes trailing slash)
358 metadata ;; Reference to compile unit where defined
359}
360</pre>
361</div>
362
John Criswell2a4b0802010-03-17 15:01:50 +0000[diff] [blame]363<p>These descriptors contain information for a file. Global variables and top
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]364 level functions would be defined using this context.k File descriptors also
365 provide context for source line correspondence. </p>
366
367<p>Each input file is encoded as a separate file descriptor in LLVM debugging
368 information output. Each file descriptor would be defined using a
369 compile unit. </p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]370
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]371</div>
372
373<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]374<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]375 <a name="format_global_variables">Global variable descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]376</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]377
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]378<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]379
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]380<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]381<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]382!1 = metadata !{
383 i32, ;; Tag = 52 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
384 ;; (DW_TAG_variable)
385 i32, ;; Unused field.
386 metadata, ;; Reference to context descriptor
387 metadata, ;; Name
388 metadata, ;; Display name (fully qualified C++ name)
389 metadata, ;; MIPS linkage name (for C++)
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]390 metadata, ;; Reference to file where defined
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]391 i32, ;; Line number where defined
392 metadata, ;; Reference to type descriptor
393 i1, ;; True if the global is local to compile unit (static)
394 i1, ;; True if the global is defined in the compile unit (not extern)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]395 {}* ;; Reference to the global variable
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]396}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]397</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]398</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]399
400<p>These descriptors provide debug information about globals variables. The
Devang Patel1c6b6812011-03-29 17:27:08 +0000[diff] [blame]401provide details such as name, type and where the variable is defined. All
402global variables are collected by named metadata <tt>!llvm.dbg.gv</tt>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]403
404</div>
405
406<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]407<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]408 <a name="format_subprograms">Subprogram descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]409</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]410
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]411<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]412
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]413<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]414<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]415!2 = metadata !{
416 i32, ;; Tag = 46 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
417 ;; (DW_TAG_subprogram)
418 i32, ;; Unused field.
419 metadata, ;; Reference to context descriptor
420 metadata, ;; Name
421 metadata, ;; Display name (fully qualified C++ name)
422 metadata, ;; MIPS linkage name (for C++)
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]423 metadata, ;; Reference to file where defined
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]424 i32, ;; Line number where defined
425 metadata, ;; Reference to type descriptor
426 i1, ;; True if the global is local to compile unit (static)
Devang Patel1d6bbd42011-04-22 23:10:17 +0000[diff] [blame]427 i1, ;; True if the global is defined in the compile unit (not extern)
428 i32, ;; Virtuality, e.g. dwarf::DW_VIRTUALITY__virtual
429 i32, ;; Index into a virtual function
Devang Patele89b7592010-06-04 22:49:55 +0000[diff] [blame]430 metadata, ;; indicates which base type contains the vtable pointer for the
431 ;; derived class
Devang Patel1d6bbd42011-04-22 23:10:17 +0000[diff] [blame]432 i1, ;; isArtificial
433 i1, ;; isOptimized
434 Function *,;; Pointer to LLVM function
435 metadata, ;; Lists function template parameters
436 metadata ;; Function declaration descriptor
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]437}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]438</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]439</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]440
441<p>These descriptors provide debug information about functions, methods and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]442 subprograms. They provide details such as name, return types and the source
Devang Patel1c6b6812011-03-29 17:27:08 +0000[diff] [blame]443 location where the subprogram is defined.
444 All subprogram descriptors are collected by a named metadata
445 <tt>!llvm.dbg.sp</tt>.
446</p>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]447
448</div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]449
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]450<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]451<h4>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]452 <a name="format_blocks">Block descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]453</h4>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]454
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]455<div>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]456
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]457<div class="doc_code">
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]458<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]459!3 = metadata !{
Devang Patel9fbc6802010-10-04 16:51:59 +0000[diff] [blame]460 i32, ;; Tag = 11 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block)
Devang Patelcac38902010-10-01 22:45:00 +0000[diff] [blame]461 metadata,;; Reference to context descriptor
462 i32, ;; Line number
Devang Patelfb30b852011-03-08 16:25:29 +0000[diff] [blame]463 i32, ;; Column number
464 metadata,;; Reference to source file
465 i32 ;; Unique ID to identify blocks from a template function
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]466}
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]467</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]468</div>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]469
470<p>These descriptors provide debug information about nested blocks within a
Devang Patelcac38902010-10-01 22:45:00 +0000[diff] [blame]471 subprogram. The line number and column numbers are used to dinstinguish
472 two lexical blocks at same depth. </p>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]473
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]474</div>
475
476<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]477<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]478 <a name="format_basic_type">Basic type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]479</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]480
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]481<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]482
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]483<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]484<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]485!4 = metadata !{
486 i32, ;; Tag = 36 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
487 ;; (DW_TAG_base_type)
488 metadata, ;; Reference to context (typically a compile unit)
489 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]490 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]491 i32, ;; Line number where defined (may be 0)
492 i64, ;; Size in bits
493 i64, ;; Alignment in bits
494 i64, ;; Offset in bits
495 i32, ;; Flags
496 i32 ;; DWARF type encoding
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]497}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]498</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]499</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]500
501<p>These descriptors define primitive types used in the code. Example int, bool
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]502 and float. The context provides the scope of the type, which is usually the
503 top level. Since basic types are not usually user defined the compile unit
504 and line number can be left as NULL and 0. The size, alignment and offset
505 are expressed in bits and can be 64 bit values. The alignment is used to
506 round the offset when embedded in a
507 <a href="#format_composite_type">composite type</a> (example to keep float
508 doubles on 64 bit boundaries.) The offset is the bit offset if embedded in
509 a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]510
511<p>The type encoding provides the details of the type. The values are typically
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]512 one of the following:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]513
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]514<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]515<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]516DW_ATE_address = 1
517DW_ATE_boolean = 2
518DW_ATE_float = 4
519DW_ATE_signed = 5
520DW_ATE_signed_char = 6
521DW_ATE_unsigned = 7
522DW_ATE_unsigned_char = 8
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]523</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]524</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]525
526</div>
527
528<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]529<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]530 <a name="format_derived_type">Derived type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]531</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]532
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]533<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]534
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]535<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]536<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]537!5 = metadata !{
538 i32, ;; Tag (see below)
539 metadata, ;; Reference to context
540 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]541 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]542 i32, ;; Line number where defined (may be 0)
Devang Patelbed5e7d2010-10-01 19:19:30 +0000[diff] [blame]543 i64, ;; Size in bits
544 i64, ;; Alignment in bits
545 i64, ;; Offset in bits
Devang Patel514b4002011-04-16 00:11:51 +0000[diff] [blame]546 metadata, ;; Reference to type derived from
547 metadata, ;; (optional) Name of the Objective C property assoicated with
548 ;; Objective-C an ivar
549 metadata, ;; (optional) Name of the Objective C property getter selector.
550 metadata, ;; (optional) Name of the Objective C property setter selector.
551 i32 ;; (optional) Objective C property attributes.
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]552}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]553</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]554</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]555
556<p>These descriptors are used to define types derived from other types. The
557value of the tag varies depending on the meaning. The following are possible
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]558tag values:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]559
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]560<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]561<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]562DW_TAG_formal_parameter = 5
563DW_TAG_member = 13
564DW_TAG_pointer_type = 15
565DW_TAG_reference_type = 16
566DW_TAG_typedef = 22
567DW_TAG_const_type = 38
568DW_TAG_volatile_type = 53
569DW_TAG_restrict_type = 55
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]570</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]571</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]572
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]573<p><tt>DW_TAG_member</tt> is used to define a member of
574 a <a href="#format_composite_type">composite type</a>
575 or <a href="#format_subprograms">subprogram</a>. The type of the member is
576 the <a href="#format_derived_type">derived
577 type</a>. <tt>DW_TAG_formal_parameter</tt> is used to define a member which
578 is a formal argument of a subprogram.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]579
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]580<p><tt>DW_TAG_typedef</tt> is used to provide a name for the derived type.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]581
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]582<p><tt>DW_TAG_pointer_type</tt>,<tt>DW_TAG_reference_type</tt>,
583 <tt>DW_TAG_const_type</tt>, <tt>DW_TAG_volatile_type</tt>
584 and <tt>DW_TAG_restrict_type</tt> are used to qualify
585 the <a href="#format_derived_type">derived type</a>. </p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]586
587<p><a href="#format_derived_type">Derived type</a> location can be determined
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]588 from the compile unit and line number. The size, alignment and offset are
589 expressed in bits and can be 64 bit values. The alignment is used to round
590 the offset when embedded in a <a href="#format_composite_type">composite
591 type</a> (example to keep float doubles on 64 bit boundaries.) The offset is
592 the bit offset if embedded in a <a href="#format_composite_type">composite
593 type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]594
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]595<p>Note that the <tt>void *</tt> type is expressed as a type derived from NULL.
596</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]597
598</div>
599
600<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]601<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]602 <a name="format_composite_type">Composite type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]603</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]604
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]605<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]606
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]607<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]608<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]609!6 = metadata !{
610 i32, ;; Tag (see below)
611 metadata, ;; Reference to context
612 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]613 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]614 i32, ;; Line number where defined (may be 0)
615 i64, ;; Size in bits
616 i64, ;; Alignment in bits
617 i64, ;; Offset in bits
618 i32, ;; Flags
619 metadata, ;; Reference to type derived from
620 metadata, ;; Reference to array of member descriptors
621 i32 ;; Runtime languages
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]622}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]623</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]624</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]625
626<p>These descriptors are used to define types that are composed of 0 or more
627elements. The value of the tag varies depending on the meaning. The following
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]628are possible tag values:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]629
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]630<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]631<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]632DW_TAG_array_type = 1
633DW_TAG_enumeration_type = 4
634DW_TAG_structure_type = 19
635DW_TAG_union_type = 23
636DW_TAG_vector_type = 259
Bruno Cardoso Lopes9d809ca2009-05-29 17:08:57 +0000[diff] [blame]637DW_TAG_subroutine_type = 21
638DW_TAG_inheritance = 28
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]639</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]640</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]641
Jim Laskey19f964e2006-06-15 20:51:43 +0000[diff] [blame]642<p>The vector flag indicates that an array type is a native packed vector.</p>
643
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000[diff] [blame]644<p>The members of array types (tag = <tt>DW_TAG_array_type</tt>) or vector types
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]645 (tag = <tt>DW_TAG_vector_type</tt>) are <a href="#format_subrange">subrange
646 descriptors</a>, each representing the range of subscripts at that level of
647 indexing.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]648
649<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]650 <a href="#format_enumeration">enumerator descriptors</a>, each representing
Devang Patel1c6b6812011-03-29 17:27:08 +0000[diff] [blame]651 the definition of enumeration value for the set. All enumeration type
652 descriptors are collected by named metadata <tt>!llvm.dbg.enum</tt>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]653
654<p>The members of structure (tag = <tt>DW_TAG_structure_type</tt>) or union (tag
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]655 = <tt>DW_TAG_union_type</tt>) types are any one of
656 the <a href="#format_basic_type">basic</a>,
657 <a href="#format_derived_type">derived</a>
658 or <a href="#format_composite_type">composite</a> type descriptors, each
659 representing a field member of the structure or union.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]660
Jim Laskey4771cca2006-08-21 21:21:06 +0000[diff] [blame]661<p>For C++ classes (tag = <tt>DW_TAG_structure_type</tt>), member descriptors
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]662 provide information about base classes, static members and member
663 functions. If a member is a <a href="#format_derived_type">derived type
664 descriptor</a> and has a tag of <tt>DW_TAG_inheritance</tt>, then the type
665 represents a base class. If the member of is
666 a <a href="#format_global_variables">global variable descriptor</a> then it
667 represents a static member. And, if the member is
668 a <a href="#format_subprograms">subprogram descriptor</a> then it represents
669 a member function. For static members and member
670 functions, <tt>getName()</tt> returns the members link or the C++ mangled
671 name. <tt>getDisplayName()</tt> the simplied version of the name.</p>
Jim Laskey4771cca2006-08-21 21:21:06 +0000[diff] [blame]672
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]673<p>The first member of subroutine (tag = <tt>DW_TAG_subroutine_type</tt>) type
674 elements is the return type for the subroutine. The remaining elements are
675 the formal arguments to the subroutine.</p>
Jim Laskey4810c262006-06-20 21:13:20 +0000[diff] [blame]676
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]677<p><a href="#format_composite_type">Composite type</a> location can be
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]678 determined from the compile unit and line number. The size, alignment and
679 offset are expressed in bits and can be 64 bit values. The alignment is used
680 to round the offset when embedded in
681 a <a href="#format_composite_type">composite type</a> (as an example, to keep
682 float doubles on 64 bit boundaries.) The offset is the bit offset if embedded
683 in a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]684
685</div>
686
687<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]688<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]689 <a name="format_subrange">Subrange descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]690</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]691
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]692<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]693
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]694<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]695<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]696!42 = metadata !{
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]697 i32, ;; Tag = 33 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subrange_type)
698 i64, ;; Low value
699 i64 ;; High value
700}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]701</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]702</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]703
704<p>These descriptors are used to define ranges of array subscripts for an array
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]705 <a href="#format_composite_type">composite type</a>. The low value defines
706 the lower bounds typically zero for C/C++. The high value is the upper
707 bounds. Values are 64 bit. High - low + 1 is the size of the array. If low
Devang Patel778947c2011-04-08 23:39:38 +0000[diff] [blame]708 > high the array bounds are not included in generated debugging information.
709</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]710
711</div>
712
713<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]714<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]715 <a name="format_enumeration">Enumerator descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]716</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]717
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]718<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]719
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]720<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]721<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]722!6 = metadata !{
723 i32, ;; Tag = 40 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
724 ;; (DW_TAG_enumerator)
725 metadata, ;; Name
726 i64 ;; Value
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]727}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]728</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]729</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]730
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]731<p>These descriptors are used to define members of an
732 enumeration <a href="#format_composite_type">composite type</a>, it
733 associates the name to the value.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]734
735</div>
736
737<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]738<h4>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]739 <a name="format_variables">Local variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]740</h4>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]741
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]742<div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]743
744<div class="doc_code">
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]745<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]746!7 = metadata !{
747 i32, ;; Tag (see below)
748 metadata, ;; Context
749 metadata, ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]750 metadata, ;; Reference to file where defined
Devang Patele1aa67c2011-03-08 16:29:40 +0000[diff] [blame]751 i32, ;; 24 bit - Line number where defined
752 ;; 8 bit - Argument number. 1 indicates 1st argument.
Bob Wilson088df092011-07-19 16:31:58 +0000[diff] [blame]753 metadata ;; Type descriptor
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]754}
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]755</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]756</div>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]757
758<p>These descriptors are used to define variables local to a sub program. The
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]759 value of the tag depends on the usage of the variable:</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]760
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]761<div class="doc_code">
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]762<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]763DW_TAG_auto_variable = 256
764DW_TAG_arg_variable = 257
765DW_TAG_return_variable = 258
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]766</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]767</div>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]768
769<p>An auto variable is any variable declared in the body of the function. An
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]770 argument variable is any variable that appears as a formal argument to the
771 function. A return variable is used to track the result of a function and
772 has no source correspondent.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]773
Jim Laskey3481e122006-03-24 09:20:27 +0000[diff] [blame]774<p>The context is either the subprogram or block where the variable is defined.
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]775 Name the source variable name. Compile unit and line indicate where the
776 variable was defined. Type descriptor defines the declared type of the
777 variable.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]778
779</div>
780
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]781</div>
782
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]783<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]784<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]785 <a name="format_common_intrinsics">Debugger intrinsic functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]786</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]787
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]788<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]789
790<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]791 provide debug information at various points in generated code.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]792
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]793<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]794<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]795 <a name="format_common_declare">llvm.dbg.declare</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]796</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]797
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]798<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]799<pre>
Devang Patel6df452c2010-10-01 19:22:16 +0000[diff] [blame]800 void %<a href="#format_common_declare">llvm.dbg.declare</a>(metadata, metadata)
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]801</pre>
802
Jim Laskey3481e122006-03-24 09:20:27 +0000[diff] [blame]803<p>This intrinsic provides information about a local element (ex. variable.) The
NAKAMURA Takumi6bd36d52011-04-09 09:51:57 +0000[diff] [blame]804 first argument is metadata holding alloca for the variable. The
Devang Patel9a8539c2011-02-01 17:22:12 +0000[diff] [blame]805 second argument is metadata containing description of the variable. </p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]806</div>
807
808<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]809<h4>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]810 <a name="format_common_value">llvm.dbg.value</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]811</h4>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]812
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]813<div>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]814<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]815 void %<a href="#format_common_value">llvm.dbg.value</a>(metadata, i64, metadata)
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]816</pre>
817
818<p>This intrinsic provides information when a user source variable is set to a
819 new value. The first argument is the new value (wrapped as metadata). The
820 second argument is the offset in the user source variable where the new value
Devang Patel9a8539c2011-02-01 17:22:12 +0000[diff] [blame]821 is written. The third argument is metadata containing description of the
822 user source variable. </p>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]823</div>
824
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]825</div>
826
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]827<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]828<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]829 <a name="format_common_lifetime">Object lifetimes and scoping</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]830</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]831
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]832<div>
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]833<p>In many languages, the local variables in functions can have their lifetimes
834 or scopes limited to a subset of a function. In the C family of languages,
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]835 for example, variables are only live (readable and writable) within the
836 source block that they are defined in. In functional languages, values are
837 only readable after they have been defined. Though this is a very obvious
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]838 concept, it is non-trivial to model in LLVM, because it has no notion of
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]839 scoping in this sense, and does not want to be tied to a language's scoping
840 rules.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]841
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]842<p>In order to handle this, the LLVM debug format uses the metadata attached to
Nick Lewyckya87014f2010-03-31 07:50:17 +0000[diff] [blame]843 llvm instructions to encode line number and scoping information. Consider
844 the following C fragment, for example:</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]845
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]846<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]847<pre>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]8481. void foo() {
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]8492. int X = 21;
8503. int Y = 22;
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]8514. {
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]8525. int Z = 23;
8536. Z = X;
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]8547. }
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]8558. X = Y;
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]8569. }
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]857</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]858</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]859
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]860<p>Compiled to LLVM, this function would be represented like this:</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]861
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]862<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]863<pre>
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]864define void @foo() nounwind ssp {
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]865entry:
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]866 %X = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
867 %Y = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
868 %Z = alloca i32, align 4 ; &lt;i32*&gt; [#uses=3]
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]869 %0 = bitcast i32* %X to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]870 call void @llvm.dbg.declare(metadata !{i32 * %X}, metadata !0), !dbg !7
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]871 store i32 21, i32* %X, !dbg !8
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]872 %1 = bitcast i32* %Y to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]873 call void @llvm.dbg.declare(metadata !{i32 * %Y}, metadata !9), !dbg !10
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]874 store i32 22, i32* %Y, !dbg !11
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]875 %2 = bitcast i32* %Z to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]876 call void @llvm.dbg.declare(metadata !{i32 * %Z}, metadata !12), !dbg !14
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]877 store i32 23, i32* %Z, !dbg !15
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]878 %tmp = load i32* %X, !dbg !16 ; &lt;i32&gt; [#uses=1]
879 %tmp1 = load i32* %Y, !dbg !16 ; &lt;i32&gt; [#uses=1]
880 %add = add nsw i32 %tmp, %tmp1, !dbg !16 ; &lt;i32&gt; [#uses=1]
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]881 store i32 %add, i32* %Z, !dbg !16
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]882 %tmp2 = load i32* %Y, !dbg !17 ; &lt;i32&gt; [#uses=1]
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]883 store i32 %tmp2, i32* %X, !dbg !17
884 ret void, !dbg !18
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]885}
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]886
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]887declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]888
889!0 = metadata !{i32 459008, metadata !1, metadata !"X",
890 metadata !3, i32 2, metadata !6}; [ DW_TAG_auto_variable ]
891!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
892!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo", metadata !"foo",
893 metadata !"foo", metadata !3, i32 1, metadata !4,
894 i1 false, i1 true}; [DW_TAG_subprogram ]
895!3 = metadata !{i32 458769, i32 0, i32 12, metadata !"foo.c",
896 metadata !"/private/tmp", metadata !"clang 1.1", i1 true,
897 i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
898!4 = metadata !{i32 458773, metadata !3, metadata !"", null, i32 0, i64 0, i64 0,
899 i64 0, i32 0, null, metadata !5, i32 0}; [DW_TAG_subroutine_type ]
900!5 = metadata !{null}
901!6 = metadata !{i32 458788, metadata !3, metadata !"int", metadata !3, i32 0,
902 i64 32, i64 32, i64 0, i32 0, i32 5}; [DW_TAG_base_type ]
903!7 = metadata !{i32 2, i32 7, metadata !1, null}
904!8 = metadata !{i32 2, i32 3, metadata !1, null}
905!9 = metadata !{i32 459008, metadata !1, metadata !"Y", metadata !3, i32 3,
906 metadata !6}; [ DW_TAG_auto_variable ]
907!10 = metadata !{i32 3, i32 7, metadata !1, null}
908!11 = metadata !{i32 3, i32 3, metadata !1, null}
909!12 = metadata !{i32 459008, metadata !13, metadata !"Z", metadata !3, i32 5,
910 metadata !6}; [ DW_TAG_auto_variable ]
911!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
912!14 = metadata !{i32 5, i32 9, metadata !13, null}
913!15 = metadata !{i32 5, i32 5, metadata !13, null}
914!16 = metadata !{i32 6, i32 5, metadata !13, null}
915!17 = metadata !{i32 8, i32 3, metadata !1, null}
916!18 = metadata !{i32 9, i32 1, metadata !2, null}
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]917</pre>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]918</div>
919
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]920<p>This example illustrates a few important details about LLVM debugging
921 information. In particular, it shows how the <tt>llvm.dbg.declare</tt>
922 intrinsic and location information, which are attached to an instruction,
923 are applied together to allow a debugger to analyze the relationship between
924 statements, variable definitions, and the code used to implement the
925 function.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]926
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]927<div class="doc_code">
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]928<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]929call void @llvm.dbg.declare(metadata, metadata !0), !dbg !7
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]930</pre>
931</div>
932
933<p>The first intrinsic
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]934 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]935 encodes debugging information for the variable <tt>X</tt>. The metadata
936 <tt>!dbg !7</tt> attached to the intrinsic provides scope information for the
937 variable <tt>X</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]938
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]939<div class="doc_code">
940<pre>
941!7 = metadata !{i32 2, i32 7, metadata !1, null}
942!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
943!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo",
944 metadata !"foo", metadata !"foo", metadata !3, i32 1,
945 metadata !4, i1 false, i1 true}; [DW_TAG_subprogram ]
946</pre>
947</div>
948
949<p>Here <tt>!7</tt> is metadata providing location information. It has four
950 fields: line number, column number, scope, and original scope. The original
951 scope represents inline location if this instruction is inlined inside a
952 caller, and is null otherwise. In this example, scope is encoded by
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]953 <tt>!1</tt>. <tt>!1</tt> represents a lexical block inside the scope
954 <tt>!2</tt>, where <tt>!2</tt> is a
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]955 <a href="#format_subprograms">subprogram descriptor</a>. This way the
956 location information attached to the intrinsics indicates that the
957 variable <tt>X</tt> is declared at line number 2 at a function level scope in
958 function <tt>foo</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]959
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]960<p>Now lets take another example.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]961
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]962<div class="doc_code">
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]963<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]964call void @llvm.dbg.declare(metadata, metadata !12), !dbg !14
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]965</pre>
966</div>
967
968<p>The second intrinsic
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]969 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]970 encodes debugging information for variable <tt>Z</tt>. The metadata
971 <tt>!dbg !14</tt> attached to the intrinsic provides scope information for
972 the variable <tt>Z</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]973
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]974<div class="doc_code">
975<pre>
976!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
977!14 = metadata !{i32 5, i32 9, metadata !13, null}
978</pre>
979</div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]980
John Criswell2a4b0802010-03-17 15:01:50 +0000[diff] [blame]981<p>Here <tt>!14</tt> indicates that <tt>Z</tt> is declared at line number 5 and
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]982 column number 9 inside of lexical scope <tt>!13</tt>. The lexical scope
983 itself resides inside of lexical scope <tt>!1</tt> described above.</p>
984
985<p>The scope information attached with each instruction provides a
986 straightforward way to find instructions covered by a scope.</p>
987
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]988</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]989
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]990</div>
991
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]992<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]993<h2>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]994 <a name="ccxx_frontend">C/C++ front-end specific debug information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]995</h2>
Misha Brukmancda6a9b2004-12-09 20:27:37 +0000[diff] [blame]996<!-- *********************************************************************** -->
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]997
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]998<div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]999
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1000<p>The C and C++ front-ends represent information about the program in a format
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1001 that is effectively identical
1002 to <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3.0</a> in
1003 terms of information content. This allows code generators to trivially
1004 support native debuggers by generating standard dwarf information, and
1005 contains enough information for non-dwarf targets to translate it as
1006 needed.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1007
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1008<p>This section describes the forms used to represent C and C++ programs. Other
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1009 languages could pattern themselves after this (which itself is tuned to
1010 representing programs in the same way that DWARF 3 does), or they could
1011 choose to provide completely different forms if they don't fit into the DWARF
1012 model. As support for debugging information gets added to the various LLVM
1013 source-language front-ends, the information used should be documented
1014 here.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1015
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1016<p>The following sections provide examples of various C/C++ constructs and the
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1017 debug information that would best describe those constructs.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1018
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1019<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1020<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1021 <a name="ccxx_compile_units">C/C++ source file information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1022</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1023
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1024<div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1025
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1026<p>Given the source files <tt>MySource.cpp</tt> and <tt>MyHeader.h</tt> located
1027 in the directory <tt>/Users/mine/sources</tt>, the following code:</p>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1028
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1029<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1030<pre>
1031#include "MyHeader.h"
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1032
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1033int main(int argc, char *argv[]) {
1034 return 0;
1035}
1036</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1037</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1038
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1039<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1040
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1041<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1042<pre>
1043...
1044;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1045;; Define the compile unit for the main source file "/Users/mine/sources/MySource.cpp".
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1046;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1047!2 = metadata !{
1048 i32 524305, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1049 i32 0, ;; Unused
1050 i32 4, ;; Language Id
1051 metadata !"MySource.cpp",
1052 metadata !"/Users/mine/sources",
1053 metadata !"4.2.1 (Based on Apple Inc. build 5649) (LLVM build 00)",
1054 i1 true, ;; Main Compile Unit
1055 i1 false, ;; Optimized compile unit
1056 metadata !"", ;; Compiler flags
1057 i32 0} ;; Runtime version
1058
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1059;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1060;; Define the file for the file "/Users/mine/sources/MySource.cpp".
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1061;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1062!1 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1063 i32 524329, ;; Tag
1064 metadata !"MySource.cpp",
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1065 metadata !"/Users/mine/sources",
Devang Patel4a7904d62010-07-13 16:53:20 +0000[diff] [blame]1066 metadata !2 ;; Compile unit
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1067}
1068
1069;;
1070;; Define the file for the file "/Users/mine/sources/Myheader.h"
1071;;
1072!3 = metadata !{
1073 i32 524329, ;; Tag
1074 metadata !"Myheader.h"
1075 metadata !"/Users/mine/sources",
Devang Patel4a7904d62010-07-13 16:53:20 +0000[diff] [blame]1076 metadata !2 ;; Compile unit
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1077}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1078
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1079...
1080</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1081</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1082
Devang Patel5bc1c4b2010-03-26 19:08:36 +0000[diff] [blame]1083<p>llvm::Instruction provides easy access to metadata attached with an
1084instruction. One can extract line number information encoded in LLVM IR
1085using <tt>Instruction::getMetadata()</tt> and
1086<tt>DILocation::getLineNumber()</tt>.
1087<pre>
1088 if (MDNode *N = I->getMetadata("dbg")) { // Here I is an LLVM instruction
1089 DILocation Loc(N); // DILocation is in DebugInfo.h
1090 unsigned Line = Loc.getLineNumber();
1091 StringRef File = Loc.getFilename();
1092 StringRef Dir = Loc.getDirectory();
1093 }
1094</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1095</div>
1096
1097<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1098<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1099 <a name="ccxx_global_variable">C/C++ global variable information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1100</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1101
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1102<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1103
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1104<p>Given an integer global variable declared as follows:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1105
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1106<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1107<pre>
1108int MyGlobal = 100;
1109</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1110</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1111
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1112<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1113
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1114<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1115<pre>
1116;;
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1117;; Define the global itself.
1118;;
1119%MyGlobal = global int 100
1120...
1121;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1122;; List of debug info of globals
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1123;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1124!llvm.dbg.gv = !{!0}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1125
1126;;
1127;; Define the global variable descriptor. Note the reference to the global
1128;; variable anchor and the global variable itself.
1129;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1130!0 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1131 i32 524340, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1132 i32 0, ;; Unused
1133 metadata !1, ;; Context
1134 metadata !"MyGlobal", ;; Name
1135 metadata !"MyGlobal", ;; Display Name
1136 metadata !"MyGlobal", ;; Linkage Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1137 metadata !3, ;; Compile Unit
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1138 i32 1, ;; Line Number
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1139 metadata !4, ;; Type
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1140 i1 false, ;; Is a local variable
1141 i1 true, ;; Is this a definition
1142 i32* @MyGlobal ;; The global variable
1143}
1144
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1145;;
1146;; Define the basic type of 32 bit signed integer. Note that since int is an
1147;; intrinsic type the source file is NULL and line 0.
1148;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1149!4 = metadata !{
1150 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1151 metadata !1, ;; Context
1152 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1153 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1154 i32 0, ;; Line number
1155 i64 32, ;; Size in Bits
1156 i64 32, ;; Align in Bits
1157 i64 0, ;; Offset in Bits
1158 i32 0, ;; Flags
1159 i32 5 ;; Encoding
1160}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1161
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1162</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1163</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1164
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1165</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1166
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1167<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1168<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1169 <a name="ccxx_subprogram">C/C++ function information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1170</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1171
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1172<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1173
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1174<p>Given a function declared as follows:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1175
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1176<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1177<pre>
1178int main(int argc, char *argv[]) {
1179 return 0;
1180}
1181</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1182</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1183
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1184<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1185
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1186<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1187<pre>
1188;;
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1189;; Define the anchor for subprograms. Note that the second field of the
1190;; anchor is 46, which is the same as the tag for subprograms
1191;; (46 = DW_TAG_subprogram.)
1192;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1193!6 = metadata !{
1194 i32 524334, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1195 i32 0, ;; Unused
1196 metadata !1, ;; Context
1197 metadata !"main", ;; Name
1198 metadata !"main", ;; Display name
1199 metadata !"main", ;; Linkage name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1200 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1201 i32 1, ;; Line number
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1202 metadata !4, ;; Type
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1203 i1 false, ;; Is local
Devang Patel9f738842011-04-05 22:52:06 +0000[diff] [blame]1204 i1 true, ;; Is definition
1205 i32 0, ;; Virtuality attribute, e.g. pure virtual function
1206 i32 0, ;; Index into virtual table for C++ methods
1207 i32 0, ;; Type that holds virtual table.
1208 i32 0, ;; Flags
1209 i1 false, ;; True if this function is optimized
1210 Function *, ;; Pointer to llvm::Function
1211 null ;; Function template parameters
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1212}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1213;;
1214;; Define the subprogram itself.
1215;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1216define i32 @main(i32 %argc, i8** %argv) {
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1217...
1218}
1219</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1220</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1221
1222</div>
1223
1224<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1225<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1226 <a name="ccxx_basic_types">C/C++ basic types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1227</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1228
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1229<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1230
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1231<p>The following are the basic type descriptors for C/C++ core types:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1232
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1233<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1234<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1235 <a name="ccxx_basic_type_bool">bool</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1236</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1237
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1238<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1239
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1240<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1241<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1242!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1243 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1244 metadata !1, ;; Context
1245 metadata !"bool", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1246 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1247 i32 0, ;; Line number
1248 i64 8, ;; Size in Bits
1249 i64 8, ;; Align in Bits
1250 i64 0, ;; Offset in Bits
1251 i32 0, ;; Flags
1252 i32 2 ;; Encoding
1253}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1254</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1255</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1256
1257</div>
1258
1259<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1260<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1261 <a name="ccxx_basic_char">char</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1262</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1263
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1264<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1265
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1266<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1267<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1268!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1269 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1270 metadata !1, ;; Context
1271 metadata !"char", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1272 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1273 i32 0, ;; Line number
1274 i64 8, ;; Size in Bits
1275 i64 8, ;; Align in Bits
1276 i64 0, ;; Offset in Bits
1277 i32 0, ;; Flags
1278 i32 6 ;; Encoding
1279}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1280</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1281</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1282
1283</div>
1284
1285<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1286<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1287 <a name="ccxx_basic_unsigned_char">unsigned char</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1288</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1289
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1290<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1291
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1292<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1293<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1294!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1295 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1296 metadata !1, ;; Context
1297 metadata !"unsigned char",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1298 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1299 i32 0, ;; Line number
1300 i64 8, ;; Size in Bits
1301 i64 8, ;; Align in Bits
1302 i64 0, ;; Offset in Bits
1303 i32 0, ;; Flags
1304 i32 8 ;; Encoding
1305}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1306</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1307</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1308
1309</div>
1310
1311<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1312<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1313 <a name="ccxx_basic_short">short</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1314</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1315
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1316<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1317
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1318<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1319<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1320!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1321 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1322 metadata !1, ;; Context
1323 metadata !"short int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1324 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1325 i32 0, ;; Line number
1326 i64 16, ;; Size in Bits
1327 i64 16, ;; Align in Bits
1328 i64 0, ;; Offset in Bits
1329 i32 0, ;; Flags
1330 i32 5 ;; Encoding
1331}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1332</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1333</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1334
1335</div>
1336
1337<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1338<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1339 <a name="ccxx_basic_unsigned_short">unsigned short</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1340</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1341
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1342<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1343
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1344<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1345<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1346!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1347 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1348 metadata !1, ;; Context
1349 metadata !"short unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1350 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1351 i32 0, ;; Line number
1352 i64 16, ;; Size in Bits
1353 i64 16, ;; Align in Bits
1354 i64 0, ;; Offset in Bits
1355 i32 0, ;; Flags
1356 i32 7 ;; Encoding
1357}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1358</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1359</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1360
1361</div>
1362
1363<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1364<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1365 <a name="ccxx_basic_int">int</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1366</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1367
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1368<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1369
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1370<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1371<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1372!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1373 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1374 metadata !1, ;; Context
1375 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1376 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1377 i32 0, ;; Line number
1378 i64 32, ;; Size in Bits
1379 i64 32, ;; Align in Bits
1380 i64 0, ;; Offset in Bits
1381 i32 0, ;; Flags
1382 i32 5 ;; Encoding
1383}
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1384</pre></div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1385
1386</div>
1387
1388<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1389<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1390 <a name="ccxx_basic_unsigned_int">unsigned int</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1391</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1392
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1393<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1394
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1395<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1396<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1397!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1398 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1399 metadata !1, ;; Context
1400 metadata !"unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1401 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1402 i32 0, ;; Line number
1403 i64 32, ;; Size in Bits
1404 i64 32, ;; Align in Bits
1405 i64 0, ;; Offset in Bits
1406 i32 0, ;; Flags
1407 i32 7 ;; Encoding
1408}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1409</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1410</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1411
1412</div>
1413
1414<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1415<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1416 <a name="ccxx_basic_long_long">long long</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1417</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1418
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1419<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1420
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1421<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1422<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1423!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1424 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1425 metadata !1, ;; Context
1426 metadata !"long long int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1427 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1428 i32 0, ;; Line number
1429 i64 64, ;; Size in Bits
1430 i64 64, ;; Align in Bits
1431 i64 0, ;; Offset in Bits
1432 i32 0, ;; Flags
1433 i32 5 ;; Encoding
1434}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1435</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1436</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1437
1438</div>
1439
1440<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1441<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1442 <a name="ccxx_basic_unsigned_long_long">unsigned long long</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1443</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1444
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1445<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1446
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1447<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1448<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1449!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1450 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1451 metadata !1, ;; Context
1452 metadata !"long long unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1453 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1454 i32 0, ;; Line number
1455 i64 64, ;; Size in Bits
1456 i64 64, ;; Align in Bits
1457 i64 0, ;; Offset in Bits
1458 i32 0, ;; Flags
1459 i32 7 ;; Encoding
1460}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1461</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1462</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1463
1464</div>
1465
1466<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1467<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1468 <a name="ccxx_basic_float">float</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1469</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1470
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1471<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1472
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1473<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1474<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1475!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1476 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1477 metadata !1, ;; Context
1478 metadata !"float",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1479 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1480 i32 0, ;; Line number
1481 i64 32, ;; Size in Bits
1482 i64 32, ;; Align in Bits
1483 i64 0, ;; Offset in Bits
1484 i32 0, ;; Flags
1485 i32 4 ;; Encoding
1486}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1487</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1488</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1489
1490</div>
1491
1492<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1493<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1494 <a name="ccxx_basic_double">double</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1495</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1496
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1497<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1498
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1499<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1500<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1501!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1502 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1503 metadata !1, ;; Context
1504 metadata !"double",;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1505 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1506 i32 0, ;; Line number
1507 i64 64, ;; Size in Bits
1508 i64 64, ;; Align in Bits
1509 i64 0, ;; Offset in Bits
1510 i32 0, ;; Flags
1511 i32 4 ;; Encoding
1512}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1513</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1514</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1515
1516</div>
1517
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1518</div>
1519
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1520<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1521<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1522 <a name="ccxx_derived_types">C/C++ derived types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1523</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1524
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1525<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1526
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1527<p>Given the following as an example of C/C++ derived type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1528
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1529<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1530<pre>
1531typedef const int *IntPtr;
1532</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1533</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1534
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1535<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1536
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1537<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1538<pre>
1539;;
1540;; Define the typedef "IntPtr".
1541;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1542!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1543 i32 524310, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1544 metadata !1, ;; Context
1545 metadata !"IntPtr", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1546 metadata !3, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1547 i32 0, ;; Line number
1548 i64 0, ;; Size in bits
1549 i64 0, ;; Align in bits
1550 i64 0, ;; Offset in bits
1551 i32 0, ;; Flags
1552 metadata !4 ;; Derived From type
1553}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1554
1555;;
1556;; Define the pointer type.
1557;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1558!4 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1559 i32 524303, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1560 metadata !1, ;; Context
1561 metadata !"", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1562 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1563 i32 0, ;; Line number
1564 i64 64, ;; Size in bits
1565 i64 64, ;; Align in bits
1566 i64 0, ;; Offset in bits
1567 i32 0, ;; Flags
1568 metadata !5 ;; Derived From type
1569}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1570;;
1571;; Define the const type.
1572;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1573!5 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1574 i32 524326, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1575 metadata !1, ;; Context
1576 metadata !"", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1577 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1578 i32 0, ;; Line number
1579 i64 32, ;; Size in bits
1580 i64 32, ;; Align in bits
1581 i64 0, ;; Offset in bits
1582 i32 0, ;; Flags
1583 metadata !6 ;; Derived From type
1584}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1585;;
1586;; Define the int type.
1587;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1588!6 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1589 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1590 metadata !1, ;; Context
1591 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1592 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1593 i32 0, ;; Line number
1594 i64 32, ;; Size in bits
1595 i64 32, ;; Align in bits
1596 i64 0, ;; Offset in bits
1597 i32 0, ;; Flags
1598 5 ;; Encoding
1599}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1600</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1601</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1602
1603</div>
1604
1605<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1606<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1607 <a name="ccxx_composite_types">C/C++ struct/union types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1608</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1609
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1610<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1611
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1612<p>Given the following as an example of C/C++ struct type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1613
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1614<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1615<pre>
1616struct Color {
1617 unsigned Red;
1618 unsigned Green;
1619 unsigned Blue;
1620};
1621</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1622</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1623
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1624<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1625
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1626<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1627<pre>
1628;;
1629;; Define basic type for unsigned int.
1630;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1631!5 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1632 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1633 metadata !1, ;; Context
1634 metadata !"unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1635 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1636 i32 0, ;; Line number
1637 i64 32, ;; Size in Bits
1638 i64 32, ;; Align in Bits
1639 i64 0, ;; Offset in Bits
1640 i32 0, ;; Flags
1641 i32 7 ;; Encoding
1642}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1643;;
1644;; Define composite type for struct Color.
1645;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1646!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1647 i32 524307, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1648 metadata !1, ;; Context
1649 metadata !"Color", ;; Name
1650 metadata !1, ;; Compile unit
1651 i32 1, ;; Line number
1652 i64 96, ;; Size in bits
1653 i64 32, ;; Align in bits
1654 i64 0, ;; Offset in bits
1655 i32 0, ;; Flags
1656 null, ;; Derived From
1657 metadata !3, ;; Elements
1658 i32 0 ;; Runtime Language
1659}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1660
1661;;
1662;; Define the Red field.
1663;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1664!4 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1665 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1666 metadata !1, ;; Context
1667 metadata !"Red", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1668 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1669 i32 2, ;; Line number
1670 i64 32, ;; Size in bits
1671 i64 32, ;; Align in bits
1672 i64 0, ;; Offset in bits
1673 i32 0, ;; Flags
1674 metadata !5 ;; Derived From type
1675}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1676
1677;;
1678;; Define the Green field.
1679;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1680!6 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1681 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1682 metadata !1, ;; Context
1683 metadata !"Green", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1684 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1685 i32 3, ;; Line number
1686 i64 32, ;; Size in bits
1687 i64 32, ;; Align in bits
1688 i64 32, ;; Offset in bits
1689 i32 0, ;; Flags
1690 metadata !5 ;; Derived From type
1691}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1692
1693;;
1694;; Define the Blue field.
1695;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1696!7 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1697 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1698 metadata !1, ;; Context
1699 metadata !"Blue", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1700 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1701 i32 4, ;; Line number
1702 i64 32, ;; Size in bits
1703 i64 32, ;; Align in bits
1704 i64 64, ;; Offset in bits
1705 i32 0, ;; Flags
1706 metadata !5 ;; Derived From type
1707}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1708
1709;;
1710;; Define the array of fields used by the composite type Color.
1711;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1712!3 = metadata !{metadata !4, metadata !6, metadata !7}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1713</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1714</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1715
1716</div>
1717
1718<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1719<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1720 <a name="ccxx_enumeration_types">C/C++ enumeration types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1721</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1722
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1723<div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1724
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1725<p>Given the following as an example of C/C++ enumeration type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1726
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1727<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1728<pre>
1729enum Trees {
1730 Spruce = 100,
1731 Oak = 200,
1732 Maple = 300
1733};
1734</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1735</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1736
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1737<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1738
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1739<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1740<pre>
1741;;
1742;; Define composite type for enum Trees
1743;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1744!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1745 i32 524292, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1746 metadata !1, ;; Context
1747 metadata !"Trees", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1748 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1749 i32 1, ;; Line number
1750 i64 32, ;; Size in bits
1751 i64 32, ;; Align in bits
1752 i64 0, ;; Offset in bits
1753 i32 0, ;; Flags
1754 null, ;; Derived From type
1755 metadata !3, ;; Elements
1756 i32 0 ;; Runtime language
1757}
Devang Patel02aac922009-08-25 05:24:07 +0000[diff] [blame]1758
Devang Patelf08e35d2009-08-26 05:01:18 +0000[diff] [blame]1759;;
1760;; Define the array of enumerators used by composite type Trees.
1761;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1762!3 = metadata !{metadata !4, metadata !5, metadata !6}
1763
1764;;
1765;; Define Spruce enumerator.
1766;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1767!4 = metadata !{i32 524328, metadata !"Spruce", i64 100}
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1768
1769;;
1770;; Define Oak enumerator.
1771;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1772!5 = metadata !{i32 524328, metadata !"Oak", i64 200}
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1773
1774;;
1775;; Define Maple enumerator.
1776;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1777!6 = metadata !{i32 524328, metadata !"Maple", i64 300}
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1778
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1779</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1780</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1781
1782</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1783
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1784</div>
1785
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1786<!-- *********************************************************************** -->
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1787
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1788<hr>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1789<address>
1790 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]1791 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1792 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]1793 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1794
1795 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]1796 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1797 Last modified: $Date$
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1798</address>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1799
1800</body>
1801</html>