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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 0780b6303b99441fef04340b7a083006484f4743 / . / docs / SourceLevelDebugging.html
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Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]6 <title>Source Level Debugging with LLVM</title>
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9<body>
10
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]11<h1>Source Level Debugging with LLVM</h1>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]12
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]13<table class="layout" style="width:100%">
14 <tr class="layout">
15 <td class="left">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]16<ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]17 <li><a href="#introduction">Introduction</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]18 <ol>
19 <li><a href="#phil">Philosophy behind LLVM debugging information</a></li>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]20 <li><a href="#consumers">Debug information consumers</a></li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]21 <li><a href="#debugopt">Debugging optimized code</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]22 </ol></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]23 <li><a href="#format">Debugging information format</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]24 <ol>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]25 <li><a href="#debug_info_descriptors">Debug information descriptors</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]26 <ul>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]27 <li><a href="#format_compile_units">Compile unit descriptors</a></li>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]28 <li><a href="#format_files">File descriptors</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]29 <li><a href="#format_global_variables">Global variable descriptors</a></li>
30 <li><a href="#format_subprograms">Subprogram descriptors</a></li>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]31 <li><a href="#format_blocks">Block descriptors</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]32 <li><a href="#format_basic_type">Basic type descriptors</a></li>
33 <li><a href="#format_derived_type">Derived type descriptors</a></li>
34 <li><a href="#format_composite_type">Composite type descriptors</a></li>
35 <li><a href="#format_subrange">Subrange descriptors</a></li>
36 <li><a href="#format_enumeration">Enumerator descriptors</a></li>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]37 <li><a href="#format_variables">Local variables</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]38 </ul></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]39 <li><a href="#format_common_intrinsics">Debugger intrinsic functions</a>
40 <ul>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]41 <li><a href="#format_common_declare">llvm.dbg.declare</a></li>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]42 <li><a href="#format_common_value">llvm.dbg.value</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]43 </ul></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]44 </ol></li>
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]45 <li><a href="#format_common_lifetime">Object lifetimes and scoping</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]46 <li><a href="#ccxx_frontend">C/C++ front-end specific debug information</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]47 <ol>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]48 <li><a href="#ccxx_compile_units">C/C++ source file information</a></li>
49 <li><a href="#ccxx_global_variable">C/C++ global variable information</a></li>
50 <li><a href="#ccxx_subprogram">C/C++ function information</a></li>
51 <li><a href="#ccxx_basic_types">C/C++ basic types</a></li>
52 <li><a href="#ccxx_derived_types">C/C++ derived types</a></li>
53 <li><a href="#ccxx_composite_types">C/C++ struct/union types</a></li>
54 <li><a href="#ccxx_enumeration_types">C/C++ enumeration types</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]55 </ol></li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]56</ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]57</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]58<td class="right">
Misha Brukmane849a1a2004-05-12 21:26:16 +0000[diff] [blame]59<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247"
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]60height="369">
61</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]62</tr></table>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]63
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]64<div class="doc_author">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]65 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
Jim Laskeyc760a922007-03-14 19:32:21 +0000[diff] [blame]66 and <a href="mailto:jlaskey@mac.com">Jim Laskey</a></p>
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]67</div>
68
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]69
70<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]71<h2><a name="introduction">Introduction</a></h2>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]72<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]73
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]74<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]75
76<p>This document is the central repository for all information pertaining to
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]77 debug information in LLVM. It describes the <a href="#format">actual format
78 that the LLVM debug information</a> takes, which is useful for those
79 interested in creating front-ends or dealing directly with the information.
Chris Lattner8ad2f982009-07-18 21:47:15 +0000[diff] [blame]80 Further, this document provides specific examples of what debug information
Chris Lattner89940752011-01-18 06:12:10 +0000[diff] [blame]81 for C/C++ looks like.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]82
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]83<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]84<h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]85 <a name="phil">Philosophy behind LLVM debugging information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]86</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]87
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]88<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]89
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]90<p>The idea of the LLVM debugging information is to capture how the important
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]94
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]95<ul>
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]99
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]102
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]106
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]110
Bill Wendling48839d92009-05-17 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 Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]115</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]116
Bill Wendling48839d92009-05-17 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 Patele4b27562009-08-28 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 Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]125
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]126<p>When a program is being debugged, a debugger interacts with the user and
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]130
131</div>
132
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]133<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]134<h3>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]135 <a name="consumers">Debug information consumers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]136</h3>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]137
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]138<div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]139
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]140<p>The role of debug information is to provide meta information normally
Bill Wendling48839d92009-05-17 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 Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]144
Chris Lattnerc3107782010-04-05 04:11:11 +0000[diff] [blame]145<p>Currently, debug information is consumed by DwarfDebug to produce dwarf
Bill Wendling48839d92009-05-17 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 Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]148
149<p>It would also be reasonable to use debug information to feed profiling tools
Bill Wendling48839d92009-05-17 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 Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]152
153<p>TODO - expound a bit more.</p>
154
155</div>
156
157<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]158<h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]159 <a name="debugopt">Debugging optimized code</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]160</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]161
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]162<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]163
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]164<p>An extremely high priority of LLVM debugging information is to make it
Bill Wendling48839d92009-05-17 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 Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]167
168<ul>
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]176
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]182
Devang Patele0bdc592011-05-31 17:45:27 +0000[diff] [blame]183 <li>LLVM debug information does not prevent optimizations from
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]184 happening (for example inlining, basic block reordering/merging/cleanup,
Devang Patelf729e912011-05-31 18:06:14 +0000[diff] [blame]185 tail duplication, etc).</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]186
Bill Wendling48839d92009-05-17 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 Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]191</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]192
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]193<p>Basically, the debug information allows you to compile a program with
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]201
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]202<p><a href="TestingGuide.html#quicktestsuite">LLVM test suite</a> provides a
Bill Wendling48839d92009-05-17 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 Patela5c05aa2008-11-21 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 Wendling48839d92009-05-17 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 Patela5c05aa2008-11-21 19:35:57 +0000[diff] [blame]217
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]218</div>
219
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]220</div>
221
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]222<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]223<h2>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]224 <a name="format">Debugging information format</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]225</h2>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]226<!-- *********************************************************************** -->
227
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]228<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]229
230<p>LLVM debugging information has been carefully designed to make it possible
Bill Wendling48839d92009-05-17 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 Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]233 particular, the use of metadata avoids duplicated debugging information from
Devang Patele4b27562009-08-28 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]237
238<p>To do this, most of the debugging information (descriptors for types,
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]239 variables, functions, source files, etc) is inserted by the language
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]240 front-end in the form of LLVM metadata. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]241
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]242<p>Debug information is designed to be agnostic about the target debugger and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]243 debugging information representation (e.g. DWARF/Stabs/etc). It uses a
Devang Patele4b27562009-08-28 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]248
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]249<p>To provide basic functionality, the LLVM debugger does have to make some
Bill Wendling48839d92009-05-17 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 Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]252 exist are <a href="#format_files">source files</a>,
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]256
257<p>This section of the documentation first describes the representation aspects
Bill Wendling48839d92009-05-17 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]260
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]261<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]262<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]263 <a name="debug_info_descriptors">Debug information descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]264</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]265
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]266<div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]267
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]268<p>In consideration of the complexity and volume of debug information, LLVM
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]269 provides a specification for well formed debug descriptors. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]270
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]271<p>Consumers of LLVM debug information expect the descriptors for program
Bill Wendling48839d92009-05-17 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 Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]279 the range 0x1000 through 0x2000 (there is a defined enum DW_TAG_user_base =
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]280 0x1000.)</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]281
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]282<p>The fields of debug descriptors used internally by LLVM
Nick Lewycky655fd032010-03-31 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 Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]285
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]286<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]287<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]288!1 = metadata !{
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]289 i32, ;; A tag
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]290 ...
291}
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]292</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]293</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]294
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]295<p><a name="LLVMDebugVersion">The first field of a descriptor is always an
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]296 <tt>i32</tt> containing a tag value identifying the content of the
Bill Wendling48839d92009-05-17 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 Lewyckyf3379da2011-07-25 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]303
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]304<p>The details of the various descriptors follow.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]305
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]306<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]307<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]308 <a name="format_compile_units">Compile unit descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]309</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]310
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]311<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]312
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]313<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]314<pre>
Devang Patele4b27562009-08-28 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 Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]327}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]328</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]329</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]330
Bill Wendling48839d92009-05-17 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]336
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]337<p>Compile unit descriptors provide the root context for objects declared in a
Devang Patel464f4ef2011-05-03 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 Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]341
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]342</div>
343
344<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]345<h4>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]346 <a name="format_files">File descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]347</h4>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]348
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]349<div>
Devang Patel4b945502010-03-09 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)
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]358 metadata ;; Unused
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]359}
360</pre>
361</div>
362
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]363<p>These descriptors contain information for a file. Global variables and top
Devang Patel4b945502010-03-09 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
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]368 information output. </p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]369
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]370</div>
371
372<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]373<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]374 <a name="format_global_variables">Global variable descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]375</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]376
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]377<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]378
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]379<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]380<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]381!1 = metadata !{
382 i32, ;; Tag = 52 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
383 ;; (DW_TAG_variable)
384 i32, ;; Unused field.
385 metadata, ;; Reference to context descriptor
386 metadata, ;; Name
387 metadata, ;; Display name (fully qualified C++ name)
388 metadata, ;; MIPS linkage name (for C++)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]389 metadata, ;; Reference to file where defined
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]390 i32, ;; Line number where defined
391 metadata, ;; Reference to type descriptor
392 i1, ;; True if the global is local to compile unit (static)
393 i1, ;; True if the global is defined in the compile unit (not extern)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]394 {}* ;; Reference to the global variable
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]395}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]396</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]397</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]398
399<p>These descriptors provide debug information about globals variables. The
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]400provide details such as name, type and where the variable is defined. All
401global variables are collected by named metadata <tt>!llvm.dbg.gv</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]402
403</div>
404
405<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]406<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]407 <a name="format_subprograms">Subprogram descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]408</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]409
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]410<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]411
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]412<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]413<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]414!2 = metadata !{
415 i32, ;; Tag = 46 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
416 ;; (DW_TAG_subprogram)
417 i32, ;; Unused field.
418 metadata, ;; Reference to context descriptor
419 metadata, ;; Name
420 metadata, ;; Display name (fully qualified C++ name)
421 metadata, ;; MIPS linkage name (for C++)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]422 metadata, ;; Reference to file where defined
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]423 i32, ;; Line number where defined
424 metadata, ;; Reference to type descriptor
425 i1, ;; True if the global is local to compile unit (static)
Devang Patel5e06bb82011-04-22 23:10:17 +0000[diff] [blame]426 i1, ;; True if the global is defined in the compile unit (not extern)
427 i32, ;; Virtuality, e.g. dwarf::DW_VIRTUALITY__virtual
428 i32, ;; Index into a virtual function
Devang Patel80ecc152010-06-04 22:49:55 +0000[diff] [blame]429 metadata, ;; indicates which base type contains the vtable pointer for the
430 ;; derived class
Devang Patel5e06bb82011-04-22 23:10:17 +0000[diff] [blame]431 i1, ;; isArtificial
432 i1, ;; isOptimized
433 Function *,;; Pointer to LLVM function
434 metadata, ;; Lists function template parameters
435 metadata ;; Function declaration descriptor
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]436}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]437</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]438</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]439
440<p>These descriptors provide debug information about functions, methods and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]441 subprograms. They provide details such as name, return types and the source
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]442 location where the subprogram is defined.
443 All subprogram descriptors are collected by a named metadata
444 <tt>!llvm.dbg.sp</tt>.
445</p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]446
447</div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]448
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]449<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]450<h4>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]451 <a name="format_blocks">Block descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]452</h4>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]453
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]454<div>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]455
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]456<div class="doc_code">
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]457<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]458!3 = metadata !{
Devang Patelc79dda22010-10-04 16:51:59 +0000[diff] [blame]459 i32, ;; Tag = 11 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block)
Devang Patel7f271fc2010-10-01 22:45:00 +0000[diff] [blame]460 metadata,;; Reference to context descriptor
461 i32, ;; Line number
Devang Patel90d81f12011-03-08 16:25:29 +0000[diff] [blame]462 i32, ;; Column number
463 metadata,;; Reference to source file
464 i32 ;; Unique ID to identify blocks from a template function
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]465}
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]466</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]467</div>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]468
469<p>These descriptors provide debug information about nested blocks within a
Devang Patel7f271fc2010-10-01 22:45:00 +0000[diff] [blame]470 subprogram. The line number and column numbers are used to dinstinguish
471 two lexical blocks at same depth. </p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]472
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]473</div>
474
475<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]476<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]477 <a name="format_basic_type">Basic type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]478</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]479
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]480<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]481
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]482<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]483<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]484!4 = metadata !{
485 i32, ;; Tag = 36 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
486 ;; (DW_TAG_base_type)
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]487 metadata, ;; Reference to context
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]488 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]489 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]490 i32, ;; Line number where defined (may be 0)
491 i64, ;; Size in bits
492 i64, ;; Alignment in bits
493 i64, ;; Offset in bits
494 i32, ;; Flags
495 i32 ;; DWARF type encoding
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]496}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]497</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]498</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]499
500<p>These descriptors define primitive types used in the code. Example int, bool
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]501 and float. The context provides the scope of the type, which is usually the
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]502 top level. Since basic types are not usually user defined the context
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]503 and line number can be left as NULL and 0. The size, alignment and offset
504 are expressed in bits and can be 64 bit values. The alignment is used to
505 round the offset when embedded in a
506 <a href="#format_composite_type">composite type</a> (example to keep float
507 doubles on 64 bit boundaries.) The offset is the bit offset if embedded in
508 a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]509
510<p>The type encoding provides the details of the type. The values are typically
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]511 one of the following:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]512
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]513<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]514<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]515DW_ATE_address = 1
516DW_ATE_boolean = 2
517DW_ATE_float = 4
518DW_ATE_signed = 5
519DW_ATE_signed_char = 6
520DW_ATE_unsigned = 7
521DW_ATE_unsigned_char = 8
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]522</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]523</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]524
525</div>
526
527<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]528<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]529 <a name="format_derived_type">Derived type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]530</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]531
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]532<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]533
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]534<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]535<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]536!5 = metadata !{
537 i32, ;; Tag (see below)
538 metadata, ;; Reference to context
539 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]540 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]541 i32, ;; Line number where defined (may be 0)
Devang Patel0ffd10b2010-10-01 19:19:30 +0000[diff] [blame]542 i64, ;; Size in bits
543 i64, ;; Alignment in bits
544 i64, ;; Offset in bits
Devang Patele9db5e22011-04-16 00:11:51 +0000[diff] [blame]545 metadata, ;; Reference to type derived from
546 metadata, ;; (optional) Name of the Objective C property assoicated with
547 ;; Objective-C an ivar
548 metadata, ;; (optional) Name of the Objective C property getter selector.
549 metadata, ;; (optional) Name of the Objective C property setter selector.
550 i32 ;; (optional) Objective C property attributes.
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]551}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]552</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]553</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]554
555<p>These descriptors are used to define types derived from other types. The
556value of the tag varies depending on the meaning. The following are possible
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]557tag values:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]558
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]559<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]560<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]561DW_TAG_formal_parameter = 5
562DW_TAG_member = 13
563DW_TAG_pointer_type = 15
564DW_TAG_reference_type = 16
565DW_TAG_typedef = 22
566DW_TAG_const_type = 38
567DW_TAG_volatile_type = 53
568DW_TAG_restrict_type = 55
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]569</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]570</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]571
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]572<p><tt>DW_TAG_member</tt> is used to define a member of
573 a <a href="#format_composite_type">composite type</a>
574 or <a href="#format_subprograms">subprogram</a>. The type of the member is
575 the <a href="#format_derived_type">derived
576 type</a>. <tt>DW_TAG_formal_parameter</tt> is used to define a member which
577 is a formal argument of a subprogram.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]578
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]579<p><tt>DW_TAG_typedef</tt> is used to provide a name for the derived type.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]580
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]581<p><tt>DW_TAG_pointer_type</tt>,<tt>DW_TAG_reference_type</tt>,
582 <tt>DW_TAG_const_type</tt>, <tt>DW_TAG_volatile_type</tt>
583 and <tt>DW_TAG_restrict_type</tt> are used to qualify
584 the <a href="#format_derived_type">derived type</a>. </p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]585
586<p><a href="#format_derived_type">Derived type</a> location can be determined
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]587 from the context and line number. The size, alignment and offset are
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]588 expressed in bits and can be 64 bit values. The alignment is used to round
589 the offset when embedded in a <a href="#format_composite_type">composite
590 type</a> (example to keep float doubles on 64 bit boundaries.) The offset is
591 the bit offset if embedded in a <a href="#format_composite_type">composite
592 type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]593
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]594<p>Note that the <tt>void *</tt> type is expressed as a type derived from NULL.
595</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]596
597</div>
598
599<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]600<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]601 <a name="format_composite_type">Composite type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]602</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]603
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]604<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]605
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]606<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]607<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]608!6 = metadata !{
609 i32, ;; Tag (see below)
610 metadata, ;; Reference to context
611 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]612 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]613 i32, ;; Line number where defined (may be 0)
614 i64, ;; Size in bits
615 i64, ;; Alignment in bits
616 i64, ;; Offset in bits
617 i32, ;; Flags
618 metadata, ;; Reference to type derived from
619 metadata, ;; Reference to array of member descriptors
620 i32 ;; Runtime languages
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]621}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]622</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]623</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]624
625<p>These descriptors are used to define types that are composed of 0 or more
626elements. The value of the tag varies depending on the meaning. The following
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]627are possible tag values:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]628
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]629<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]630<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]631DW_TAG_array_type = 1
632DW_TAG_enumeration_type = 4
633DW_TAG_structure_type = 19
634DW_TAG_union_type = 23
635DW_TAG_vector_type = 259
Bruno Cardoso Lopesd80ddc02009-05-29 17:08:57 +0000[diff] [blame]636DW_TAG_subroutine_type = 21
637DW_TAG_inheritance = 28
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]638</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]639</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]640
Jim Laskeyf8a01a92006-06-15 20:51:43 +0000[diff] [blame]641<p>The vector flag indicates that an array type is a native packed vector.</p>
642
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]643<p>The members of array types (tag = <tt>DW_TAG_array_type</tt>) or vector types
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]644 (tag = <tt>DW_TAG_vector_type</tt>) are <a href="#format_subrange">subrange
645 descriptors</a>, each representing the range of subscripts at that level of
646 indexing.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]647
648<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]649 <a href="#format_enumeration">enumerator descriptors</a>, each representing
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]650 the definition of enumeration value for the set. All enumeration type
651 descriptors are collected by named metadata <tt>!llvm.dbg.enum</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]652
653<p>The members of structure (tag = <tt>DW_TAG_structure_type</tt>) or union (tag
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]654 = <tt>DW_TAG_union_type</tt>) types are any one of
655 the <a href="#format_basic_type">basic</a>,
656 <a href="#format_derived_type">derived</a>
657 or <a href="#format_composite_type">composite</a> type descriptors, each
658 representing a field member of the structure or union.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]659
Jim Laskey4a9df242006-08-21 21:21:06 +0000[diff] [blame]660<p>For C++ classes (tag = <tt>DW_TAG_structure_type</tt>), member descriptors
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]661 provide information about base classes, static members and member
662 functions. If a member is a <a href="#format_derived_type">derived type
663 descriptor</a> and has a tag of <tt>DW_TAG_inheritance</tt>, then the type
664 represents a base class. If the member of is
665 a <a href="#format_global_variables">global variable descriptor</a> then it
666 represents a static member. And, if the member is
667 a <a href="#format_subprograms">subprogram descriptor</a> then it represents
668 a member function. For static members and member
669 functions, <tt>getName()</tt> returns the members link or the C++ mangled
670 name. <tt>getDisplayName()</tt> the simplied version of the name.</p>
Jim Laskey4a9df242006-08-21 21:21:06 +0000[diff] [blame]671
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]672<p>The first member of subroutine (tag = <tt>DW_TAG_subroutine_type</tt>) type
673 elements is the return type for the subroutine. The remaining elements are
674 the formal arguments to the subroutine.</p>
Jim Laskey094ee722006-06-20 21:13:20 +0000[diff] [blame]675
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]676<p><a href="#format_composite_type">Composite type</a> location can be
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]677 determined from the context and line number. The size, alignment and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]678 offset are expressed in bits and can be 64 bit values. The alignment is used
679 to round the offset when embedded in
680 a <a href="#format_composite_type">composite type</a> (as an example, to keep
681 float doubles on 64 bit boundaries.) The offset is the bit offset if embedded
682 in a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]683
684</div>
685
686<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]687<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]688 <a name="format_subrange">Subrange descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]689</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]690
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]691<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]692
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]693<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]694<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]695!42 = metadata !{
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]696 i32, ;; Tag = 33 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subrange_type)
697 i64, ;; Low value
698 i64 ;; High value
699}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]700</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]701</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]702
703<p>These descriptors are used to define ranges of array subscripts for an array
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]704 <a href="#format_composite_type">composite type</a>. The low value defines
705 the lower bounds typically zero for C/C++. The high value is the upper
706 bounds. Values are 64 bit. High - low + 1 is the size of the array. If low
Devang Patel3f932a72011-04-08 23:39:38 +0000[diff] [blame]707 > high the array bounds are not included in generated debugging information.
708</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]709
710</div>
711
712<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]713<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]714 <a name="format_enumeration">Enumerator descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]715</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]716
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]717<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]718
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]719<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]720<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]721!6 = metadata !{
722 i32, ;; Tag = 40 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
723 ;; (DW_TAG_enumerator)
724 metadata, ;; Name
725 i64 ;; Value
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]726}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]727</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]728</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]729
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]730<p>These descriptors are used to define members of an
731 enumeration <a href="#format_composite_type">composite type</a>, it
732 associates the name to the value.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]733
734</div>
735
736<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]737<h4>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]738 <a name="format_variables">Local variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]739</h4>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]740
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]741<div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]742
743<div class="doc_code">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]744<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]745!7 = metadata !{
746 i32, ;; Tag (see below)
747 metadata, ;; Context
748 metadata, ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]749 metadata, ;; Reference to file where defined
Devang Patela83688f2011-03-08 16:29:40 +0000[diff] [blame]750 i32, ;; 24 bit - Line number where defined
751 ;; 8 bit - Argument number. 1 indicates 1st argument.
Devang Patel0a2a3062011-07-27 18:14:50 +0000[diff] [blame]752 metadata, ;; Type descriptor
753 i32, ;; flags
754 metadata ;; (optional) Reference to inline location
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]755}
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]756</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]757</div>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]758
759<p>These descriptors are used to define variables local to a sub program. The
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]760 value of the tag depends on the usage of the variable:</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]761
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]762<div class="doc_code">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]763<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]764DW_TAG_auto_variable = 256
765DW_TAG_arg_variable = 257
766DW_TAG_return_variable = 258
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]767</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]768</div>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]769
770<p>An auto variable is any variable declared in the body of the function. An
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]771 argument variable is any variable that appears as a formal argument to the
772 function. A return variable is used to track the result of a function and
773 has no source correspondent.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]774
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame]775<p>The context is either the subprogram or block where the variable is defined.
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]776 Name the source variable name. Context and line indicate where the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]777 variable was defined. Type descriptor defines the declared type of the
778 variable.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]779
780</div>
781
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]782</div>
783
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]784<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]785<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]786 <a name="format_common_intrinsics">Debugger intrinsic functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]787</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]788
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]789<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]790
791<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]792 provide debug information at various points in generated code.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]793
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]794<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]795<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]796 <a name="format_common_declare">llvm.dbg.declare</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]797</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]798
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]799<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]800<pre>
Devang Patel4c7c0c62010-10-01 19:22:16 +0000[diff] [blame]801 void %<a href="#format_common_declare">llvm.dbg.declare</a>(metadata, metadata)
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]802</pre>
803
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame]804<p>This intrinsic provides information about a local element (ex. variable.) The
NAKAMURA Takumi4d6deb02011-04-09 09:51:57 +0000[diff] [blame]805 first argument is metadata holding alloca for the variable. The
Devang Patele136e502011-02-01 17:22:12 +0000[diff] [blame]806 second argument is metadata containing description of the variable. </p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]807</div>
808
809<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]810<h4>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]811 <a name="format_common_value">llvm.dbg.value</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]812</h4>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]813
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]814<div>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]815<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]816 void %<a href="#format_common_value">llvm.dbg.value</a>(metadata, i64, metadata)
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]817</pre>
818
819<p>This intrinsic provides information when a user source variable is set to a
820 new value. The first argument is the new value (wrapped as metadata). The
821 second argument is the offset in the user source variable where the new value
Devang Patele136e502011-02-01 17:22:12 +0000[diff] [blame]822 is written. The third argument is metadata containing description of the
823 user source variable. </p>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]824</div>
825
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]826</div>
827
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]828<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]829<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]830 <a name="format_common_lifetime">Object lifetimes and scoping</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]831</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]832
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]833<div>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]834<p>In many languages, the local variables in functions can have their lifetimes
835 or scopes limited to a subset of a function. In the C family of languages,
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]836 for example, variables are only live (readable and writable) within the
837 source block that they are defined in. In functional languages, values are
838 only readable after they have been defined. Though this is a very obvious
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]839 concept, it is non-trivial to model in LLVM, because it has no notion of
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]840 scoping in this sense, and does not want to be tied to a language's scoping
841 rules.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]842
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]843<p>In order to handle this, the LLVM debug format uses the metadata attached to
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]844 llvm instructions to encode line number and scoping information. Consider
845 the following C fragment, for example:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]846
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]847<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]848<pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8491. void foo() {
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8502. int X = 21;
8513. int Y = 22;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8524. {
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8535. int Z = 23;
8546. Z = X;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8557. }
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8568. X = Y;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8579. }
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]858</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]859</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]860
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]861<p>Compiled to LLVM, this function would be represented like this:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]862
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]863<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]864<pre>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]865define void @foo() nounwind ssp {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]866entry:
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]867 %X = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
868 %Y = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
869 %Z = alloca i32, align 4 ; &lt;i32*&gt; [#uses=3]
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]870 %0 = bitcast i32* %X to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]871 call void @llvm.dbg.declare(metadata !{i32 * %X}, metadata !0), !dbg !7
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]872 store i32 21, i32* %X, !dbg !8
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]873 %1 = bitcast i32* %Y to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]874 call void @llvm.dbg.declare(metadata !{i32 * %Y}, metadata !9), !dbg !10
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]875 store i32 22, i32* %Y, !dbg !11
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]876 %2 = bitcast i32* %Z to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]877 call void @llvm.dbg.declare(metadata !{i32 * %Z}, metadata !12), !dbg !14
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]878 store i32 23, i32* %Z, !dbg !15
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]879 %tmp = load i32* %X, !dbg !16 ; &lt;i32&gt; [#uses=1]
880 %tmp1 = load i32* %Y, !dbg !16 ; &lt;i32&gt; [#uses=1]
881 %add = add nsw i32 %tmp, %tmp1, !dbg !16 ; &lt;i32&gt; [#uses=1]
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]882 store i32 %add, i32* %Z, !dbg !16
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]883 %tmp2 = load i32* %Y, !dbg !17 ; &lt;i32&gt; [#uses=1]
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]884 store i32 %tmp2, i32* %X, !dbg !17
885 ret void, !dbg !18
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]886}
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]887
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]888declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]889
890!0 = metadata !{i32 459008, metadata !1, metadata !"X",
891 metadata !3, i32 2, metadata !6}; [ DW_TAG_auto_variable ]
892!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
893!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo", metadata !"foo",
894 metadata !"foo", metadata !3, i32 1, metadata !4,
895 i1 false, i1 true}; [DW_TAG_subprogram ]
896!3 = metadata !{i32 458769, i32 0, i32 12, metadata !"foo.c",
897 metadata !"/private/tmp", metadata !"clang 1.1", i1 true,
898 i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
899!4 = metadata !{i32 458773, metadata !3, metadata !"", null, i32 0, i64 0, i64 0,
900 i64 0, i32 0, null, metadata !5, i32 0}; [DW_TAG_subroutine_type ]
901!5 = metadata !{null}
902!6 = metadata !{i32 458788, metadata !3, metadata !"int", metadata !3, i32 0,
903 i64 32, i64 32, i64 0, i32 0, i32 5}; [DW_TAG_base_type ]
904!7 = metadata !{i32 2, i32 7, metadata !1, null}
905!8 = metadata !{i32 2, i32 3, metadata !1, null}
906!9 = metadata !{i32 459008, metadata !1, metadata !"Y", metadata !3, i32 3,
907 metadata !6}; [ DW_TAG_auto_variable ]
908!10 = metadata !{i32 3, i32 7, metadata !1, null}
909!11 = metadata !{i32 3, i32 3, metadata !1, null}
910!12 = metadata !{i32 459008, metadata !13, metadata !"Z", metadata !3, i32 5,
911 metadata !6}; [ DW_TAG_auto_variable ]
912!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
913!14 = metadata !{i32 5, i32 9, metadata !13, null}
914!15 = metadata !{i32 5, i32 5, metadata !13, null}
915!16 = metadata !{i32 6, i32 5, metadata !13, null}
916!17 = metadata !{i32 8, i32 3, metadata !1, null}
917!18 = metadata !{i32 9, i32 1, metadata !2, null}
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]918</pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]919</div>
920
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]921<p>This example illustrates a few important details about LLVM debugging
922 information. In particular, it shows how the <tt>llvm.dbg.declare</tt>
923 intrinsic and location information, which are attached to an instruction,
924 are applied together to allow a debugger to analyze the relationship between
925 statements, variable definitions, and the code used to implement the
926 function.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]927
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]928<div class="doc_code">
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]929<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]930call void @llvm.dbg.declare(metadata, metadata !0), !dbg !7
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]931</pre>
932</div>
933
934<p>The first intrinsic
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]935 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]936 encodes debugging information for the variable <tt>X</tt>. The metadata
937 <tt>!dbg !7</tt> attached to the intrinsic provides scope information for the
938 variable <tt>X</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]939
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]940<div class="doc_code">
941<pre>
942!7 = metadata !{i32 2, i32 7, metadata !1, null}
943!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
944!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo",
945 metadata !"foo", metadata !"foo", metadata !3, i32 1,
946 metadata !4, i1 false, i1 true}; [DW_TAG_subprogram ]
947</pre>
948</div>
949
950<p>Here <tt>!7</tt> is metadata providing location information. It has four
951 fields: line number, column number, scope, and original scope. The original
952 scope represents inline location if this instruction is inlined inside a
953 caller, and is null otherwise. In this example, scope is encoded by
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]954 <tt>!1</tt>. <tt>!1</tt> represents a lexical block inside the scope
955 <tt>!2</tt>, where <tt>!2</tt> is a
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]956 <a href="#format_subprograms">subprogram descriptor</a>. This way the
957 location information attached to the intrinsics indicates that the
958 variable <tt>X</tt> is declared at line number 2 at a function level scope in
959 function <tt>foo</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]960
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]961<p>Now lets take another example.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]962
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]963<div class="doc_code">
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]964<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]965call void @llvm.dbg.declare(metadata, metadata !12), !dbg !14
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]966</pre>
967</div>
968
969<p>The second intrinsic
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]970 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]971 encodes debugging information for variable <tt>Z</tt>. The metadata
972 <tt>!dbg !14</tt> attached to the intrinsic provides scope information for
973 the variable <tt>Z</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]974
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]975<div class="doc_code">
976<pre>
977!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
978!14 = metadata !{i32 5, i32 9, metadata !13, null}
979</pre>
980</div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]981
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]982<p>Here <tt>!14</tt> indicates that <tt>Z</tt> is declared at line number 5 and
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]983 column number 9 inside of lexical scope <tt>!13</tt>. The lexical scope
984 itself resides inside of lexical scope <tt>!1</tt> described above.</p>
985
986<p>The scope information attached with each instruction provides a
987 straightforward way to find instructions covered by a scope.</p>
988
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]989</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]990
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]991</div>
992
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]993<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]994<h2>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]995 <a name="ccxx_frontend">C/C++ front-end specific debug information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]996</h2>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]997<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]998
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]999<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1000
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1001<p>The C and C++ front-ends represent information about the program in a format
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1002 that is effectively identical
1003 to <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3.0</a> in
1004 terms of information content. This allows code generators to trivially
1005 support native debuggers by generating standard dwarf information, and
1006 contains enough information for non-dwarf targets to translate it as
1007 needed.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1008
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1009<p>This section describes the forms used to represent C and C++ programs. Other
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1010 languages could pattern themselves after this (which itself is tuned to
1011 representing programs in the same way that DWARF 3 does), or they could
1012 choose to provide completely different forms if they don't fit into the DWARF
1013 model. As support for debugging information gets added to the various LLVM
1014 source-language front-ends, the information used should be documented
1015 here.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1016
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1017<p>The following sections provide examples of various C/C++ constructs and the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1018 debug information that would best describe those constructs.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1019
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1020<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1021<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1022 <a name="ccxx_compile_units">C/C++ source file information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1023</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1024
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1025<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1026
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1027<p>Given the source files <tt>MySource.cpp</tt> and <tt>MyHeader.h</tt> located
1028 in the directory <tt>/Users/mine/sources</tt>, the following code:</p>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1029
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1030<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1031<pre>
1032#include "MyHeader.h"
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1033
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1034int main(int argc, char *argv[]) {
1035 return 0;
1036}
1037</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1038</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1039
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1040<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1041
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1042<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1043<pre>
1044...
1045;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1046;; Define the compile unit for the main source file "/Users/mine/sources/MySource.cpp".
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1047;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1048!2 = metadata !{
1049 i32 524305, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1050 i32 0, ;; Unused
1051 i32 4, ;; Language Id
1052 metadata !"MySource.cpp",
1053 metadata !"/Users/mine/sources",
1054 metadata !"4.2.1 (Based on Apple Inc. build 5649) (LLVM build 00)",
1055 i1 true, ;; Main Compile Unit
1056 i1 false, ;; Optimized compile unit
1057 metadata !"", ;; Compiler flags
1058 i32 0} ;; Runtime version
1059
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1060;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1061;; Define the file for the file "/Users/mine/sources/MySource.cpp".
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1062;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1063!1 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1064 i32 524329, ;; Tag
1065 metadata !"MySource.cpp",
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1066 metadata !"/Users/mine/sources",
Devang Patel9fea9c22010-07-13 16:53:20 +0000[diff] [blame]1067 metadata !2 ;; Compile unit
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1068}
1069
1070;;
1071;; Define the file for the file "/Users/mine/sources/Myheader.h"
1072;;
1073!3 = metadata !{
1074 i32 524329, ;; Tag
1075 metadata !"Myheader.h"
1076 metadata !"/Users/mine/sources",
Devang Patel9fea9c22010-07-13 16:53:20 +0000[diff] [blame]1077 metadata !2 ;; Compile unit
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1078}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1079
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1080...
1081</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1082</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1083
Devang Pateld98ec5f2010-03-26 19:08:36 +0000[diff] [blame]1084<p>llvm::Instruction provides easy access to metadata attached with an
1085instruction. One can extract line number information encoded in LLVM IR
1086using <tt>Instruction::getMetadata()</tt> and
1087<tt>DILocation::getLineNumber()</tt>.
1088<pre>
1089 if (MDNode *N = I->getMetadata("dbg")) { // Here I is an LLVM instruction
1090 DILocation Loc(N); // DILocation is in DebugInfo.h
1091 unsigned Line = Loc.getLineNumber();
1092 StringRef File = Loc.getFilename();
1093 StringRef Dir = Loc.getDirectory();
1094 }
1095</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1096</div>
1097
1098<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1099<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1100 <a name="ccxx_global_variable">C/C++ global variable information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1101</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1102
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1103<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1104
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1105<p>Given an integer global variable declared as follows:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1106
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1107<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1108<pre>
1109int MyGlobal = 100;
1110</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1111</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1112
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1113<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1114
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1115<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1116<pre>
1117;;
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1118;; Define the global itself.
1119;;
1120%MyGlobal = global int 100
1121...
1122;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1123;; List of debug info of globals
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1124;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1125!llvm.dbg.gv = !{!0}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1126
1127;;
1128;; Define the global variable descriptor. Note the reference to the global
1129;; variable anchor and the global variable itself.
1130;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1131!0 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1132 i32 524340, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1133 i32 0, ;; Unused
1134 metadata !1, ;; Context
1135 metadata !"MyGlobal", ;; Name
1136 metadata !"MyGlobal", ;; Display Name
1137 metadata !"MyGlobal", ;; Linkage Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1138 metadata !3, ;; Compile Unit
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1139 i32 1, ;; Line Number
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1140 metadata !4, ;; Type
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1141 i1 false, ;; Is a local variable
1142 i1 true, ;; Is this a definition
1143 i32* @MyGlobal ;; The global variable
1144}
1145
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1146;;
1147;; Define the basic type of 32 bit signed integer. Note that since int is an
1148;; intrinsic type the source file is NULL and line 0.
1149;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1150!4 = metadata !{
1151 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1152 metadata !1, ;; Context
1153 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1154 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1155 i32 0, ;; Line number
1156 i64 32, ;; Size in Bits
1157 i64 32, ;; Align in Bits
1158 i64 0, ;; Offset in Bits
1159 i32 0, ;; Flags
1160 i32 5 ;; Encoding
1161}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1162
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1163</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1164</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1165
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1166</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1167
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1168<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1169<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1170 <a name="ccxx_subprogram">C/C++ function information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1171</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1172
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1173<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1174
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1175<p>Given a function declared as follows:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1176
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1177<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1178<pre>
1179int main(int argc, char *argv[]) {
1180 return 0;
1181}
1182</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1183</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1184
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1185<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1186
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1187<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1188<pre>
1189;;
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1190;; Define the anchor for subprograms. Note that the second field of the
1191;; anchor is 46, which is the same as the tag for subprograms
1192;; (46 = DW_TAG_subprogram.)
1193;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1194!6 = metadata !{
1195 i32 524334, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1196 i32 0, ;; Unused
1197 metadata !1, ;; Context
1198 metadata !"main", ;; Name
1199 metadata !"main", ;; Display name
1200 metadata !"main", ;; Linkage name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1201 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1202 i32 1, ;; Line number
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1203 metadata !4, ;; Type
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1204 i1 false, ;; Is local
Devang Patelda194752011-04-05 22:52:06 +0000[diff] [blame]1205 i1 true, ;; Is definition
1206 i32 0, ;; Virtuality attribute, e.g. pure virtual function
1207 i32 0, ;; Index into virtual table for C++ methods
1208 i32 0, ;; Type that holds virtual table.
1209 i32 0, ;; Flags
1210 i1 false, ;; True if this function is optimized
1211 Function *, ;; Pointer to llvm::Function
1212 null ;; Function template parameters
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1213}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1214;;
1215;; Define the subprogram itself.
1216;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1217define i32 @main(i32 %argc, i8** %argv) {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1218...
1219}
1220</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1221</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1222
1223</div>
1224
1225<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1226<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1227 <a name="ccxx_basic_types">C/C++ basic types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1228</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1229
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1230<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1231
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1232<p>The following are the basic type descriptors for C/C++ core types:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1233
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1234<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1235<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1236 <a name="ccxx_basic_type_bool">bool</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1237</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1238
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1239<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1240
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1241<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1242<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1243!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1244 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1245 metadata !1, ;; Context
1246 metadata !"bool", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1247 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1248 i32 0, ;; Line number
1249 i64 8, ;; Size in Bits
1250 i64 8, ;; Align in Bits
1251 i64 0, ;; Offset in Bits
1252 i32 0, ;; Flags
1253 i32 2 ;; Encoding
1254}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1255</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1256</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1257
1258</div>
1259
1260<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1261<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1262 <a name="ccxx_basic_char">char</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1263</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1264
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1265<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1266
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1267<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1268<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1269!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1270 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1271 metadata !1, ;; Context
1272 metadata !"char", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1273 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1274 i32 0, ;; Line number
1275 i64 8, ;; Size in Bits
1276 i64 8, ;; Align in Bits
1277 i64 0, ;; Offset in Bits
1278 i32 0, ;; Flags
1279 i32 6 ;; Encoding
1280}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1281</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1282</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1283
1284</div>
1285
1286<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1287<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1288 <a name="ccxx_basic_unsigned_char">unsigned char</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1289</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1290
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1291<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1292
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1293<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1294<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1295!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1296 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1297 metadata !1, ;; Context
1298 metadata !"unsigned char",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1299 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1300 i32 0, ;; Line number
1301 i64 8, ;; Size in Bits
1302 i64 8, ;; Align in Bits
1303 i64 0, ;; Offset in Bits
1304 i32 0, ;; Flags
1305 i32 8 ;; Encoding
1306}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1307</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1308</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1309
1310</div>
1311
1312<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1313<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1314 <a name="ccxx_basic_short">short</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1315</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1316
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1317<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1318
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1319<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1320<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1321!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1322 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1323 metadata !1, ;; Context
1324 metadata !"short int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1325 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1326 i32 0, ;; Line number
1327 i64 16, ;; Size in Bits
1328 i64 16, ;; Align in Bits
1329 i64 0, ;; Offset in Bits
1330 i32 0, ;; Flags
1331 i32 5 ;; Encoding
1332}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1333</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1334</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1335
1336</div>
1337
1338<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1339<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1340 <a name="ccxx_basic_unsigned_short">unsigned short</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1341</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1342
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1343<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1344
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1345<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1346<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1347!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1348 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1349 metadata !1, ;; Context
1350 metadata !"short unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1351 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1352 i32 0, ;; Line number
1353 i64 16, ;; Size in Bits
1354 i64 16, ;; Align in Bits
1355 i64 0, ;; Offset in Bits
1356 i32 0, ;; Flags
1357 i32 7 ;; Encoding
1358}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1359</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1360</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1361
1362</div>
1363
1364<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1365<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1366 <a name="ccxx_basic_int">int</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1367</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1368
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1369<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1370
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1371<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1372<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1373!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1374 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1375 metadata !1, ;; Context
1376 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1377 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1378 i32 0, ;; Line number
1379 i64 32, ;; Size in Bits
1380 i64 32, ;; Align in Bits
1381 i64 0, ;; Offset in Bits
1382 i32 0, ;; Flags
1383 i32 5 ;; Encoding
1384}
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1385</pre></div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1386
1387</div>
1388
1389<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1390<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1391 <a name="ccxx_basic_unsigned_int">unsigned int</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1392</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1393
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1394<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1395
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1396<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1397<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1398!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1399 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1400 metadata !1, ;; Context
1401 metadata !"unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1402 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1403 i32 0, ;; Line number
1404 i64 32, ;; Size in Bits
1405 i64 32, ;; Align in Bits
1406 i64 0, ;; Offset in Bits
1407 i32 0, ;; Flags
1408 i32 7 ;; Encoding
1409}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1410</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1411</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1412
1413</div>
1414
1415<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1416<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1417 <a name="ccxx_basic_long_long">long long</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1418</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1419
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1420<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1421
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1422<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1423<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1424!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1425 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1426 metadata !1, ;; Context
1427 metadata !"long long int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1428 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1429 i32 0, ;; Line number
1430 i64 64, ;; Size in Bits
1431 i64 64, ;; Align in Bits
1432 i64 0, ;; Offset in Bits
1433 i32 0, ;; Flags
1434 i32 5 ;; Encoding
1435}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1436</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1437</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1438
1439</div>
1440
1441<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1442<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1443 <a name="ccxx_basic_unsigned_long_long">unsigned long long</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1444</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1445
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1446<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1447
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1448<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1449<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1450!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1451 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1452 metadata !1, ;; Context
1453 metadata !"long long unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1454 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1455 i32 0, ;; Line number
1456 i64 64, ;; Size in Bits
1457 i64 64, ;; Align in Bits
1458 i64 0, ;; Offset in Bits
1459 i32 0, ;; Flags
1460 i32 7 ;; Encoding
1461}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1462</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1463</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1464
1465</div>
1466
1467<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1468<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1469 <a name="ccxx_basic_float">float</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1470</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1471
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1472<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1473
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1474<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1475<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1476!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1477 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1478 metadata !1, ;; Context
1479 metadata !"float",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1480 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1481 i32 0, ;; Line number
1482 i64 32, ;; Size in Bits
1483 i64 32, ;; Align in Bits
1484 i64 0, ;; Offset in Bits
1485 i32 0, ;; Flags
1486 i32 4 ;; Encoding
1487}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1488</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1489</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1490
1491</div>
1492
1493<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1494<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1495 <a name="ccxx_basic_double">double</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1496</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1497
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1498<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1499
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1500<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1501<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1502!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1503 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1504 metadata !1, ;; Context
1505 metadata !"double",;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1506 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1507 i32 0, ;; Line number
1508 i64 64, ;; Size in Bits
1509 i64 64, ;; Align in Bits
1510 i64 0, ;; Offset in Bits
1511 i32 0, ;; Flags
1512 i32 4 ;; Encoding
1513}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1514</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1515</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1516
1517</div>
1518
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1519</div>
1520
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1521<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1522<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1523 <a name="ccxx_derived_types">C/C++ derived types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1524</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1525
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1526<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1527
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1528<p>Given the following as an example of C/C++ derived type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1529
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1530<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1531<pre>
1532typedef const int *IntPtr;
1533</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1534</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1535
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1536<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1537
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1538<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1539<pre>
1540;;
1541;; Define the typedef "IntPtr".
1542;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1543!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1544 i32 524310, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1545 metadata !1, ;; Context
1546 metadata !"IntPtr", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1547 metadata !3, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1548 i32 0, ;; Line number
1549 i64 0, ;; Size in bits
1550 i64 0, ;; Align in bits
1551 i64 0, ;; Offset in bits
1552 i32 0, ;; Flags
1553 metadata !4 ;; Derived From type
1554}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1555
1556;;
1557;; Define the pointer type.
1558;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1559!4 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1560 i32 524303, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1561 metadata !1, ;; Context
1562 metadata !"", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1563 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1564 i32 0, ;; Line number
1565 i64 64, ;; Size in bits
1566 i64 64, ;; Align in bits
1567 i64 0, ;; Offset in bits
1568 i32 0, ;; Flags
1569 metadata !5 ;; Derived From type
1570}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1571;;
1572;; Define the const type.
1573;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1574!5 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1575 i32 524326, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1576 metadata !1, ;; Context
1577 metadata !"", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1578 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1579 i32 0, ;; Line number
1580 i64 32, ;; Size in bits
1581 i64 32, ;; Align in bits
1582 i64 0, ;; Offset in bits
1583 i32 0, ;; Flags
1584 metadata !6 ;; Derived From type
1585}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1586;;
1587;; Define the int type.
1588;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1589!6 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1590 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1591 metadata !1, ;; Context
1592 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1593 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1594 i32 0, ;; Line number
1595 i64 32, ;; Size in bits
1596 i64 32, ;; Align in bits
1597 i64 0, ;; Offset in bits
1598 i32 0, ;; Flags
1599 5 ;; Encoding
1600}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1601</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1602</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1603
1604</div>
1605
1606<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1607<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1608 <a name="ccxx_composite_types">C/C++ struct/union types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1609</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1610
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1611<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1612
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1613<p>Given the following as an example of C/C++ struct type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1614
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1615<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1616<pre>
1617struct Color {
1618 unsigned Red;
1619 unsigned Green;
1620 unsigned Blue;
1621};
1622</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1623</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1624
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1625<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1626
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1627<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1628<pre>
1629;;
1630;; Define basic type for unsigned int.
1631;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1632!5 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1633 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1634 metadata !1, ;; Context
1635 metadata !"unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1636 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1637 i32 0, ;; Line number
1638 i64 32, ;; Size in Bits
1639 i64 32, ;; Align in Bits
1640 i64 0, ;; Offset in Bits
1641 i32 0, ;; Flags
1642 i32 7 ;; Encoding
1643}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1644;;
1645;; Define composite type for struct Color.
1646;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1647!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1648 i32 524307, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1649 metadata !1, ;; Context
1650 metadata !"Color", ;; Name
1651 metadata !1, ;; Compile unit
1652 i32 1, ;; Line number
1653 i64 96, ;; Size in bits
1654 i64 32, ;; Align in bits
1655 i64 0, ;; Offset in bits
1656 i32 0, ;; Flags
1657 null, ;; Derived From
1658 metadata !3, ;; Elements
1659 i32 0 ;; Runtime Language
1660}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1661
1662;;
1663;; Define the Red field.
1664;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1665!4 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1666 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1667 metadata !1, ;; Context
1668 metadata !"Red", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1669 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1670 i32 2, ;; Line number
1671 i64 32, ;; Size in bits
1672 i64 32, ;; Align in bits
1673 i64 0, ;; Offset in bits
1674 i32 0, ;; Flags
1675 metadata !5 ;; Derived From type
1676}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1677
1678;;
1679;; Define the Green field.
1680;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1681!6 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1682 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1683 metadata !1, ;; Context
1684 metadata !"Green", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1685 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1686 i32 3, ;; Line number
1687 i64 32, ;; Size in bits
1688 i64 32, ;; Align in bits
1689 i64 32, ;; Offset in bits
1690 i32 0, ;; Flags
1691 metadata !5 ;; Derived From type
1692}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1693
1694;;
1695;; Define the Blue field.
1696;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1697!7 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1698 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1699 metadata !1, ;; Context
1700 metadata !"Blue", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1701 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1702 i32 4, ;; Line number
1703 i64 32, ;; Size in bits
1704 i64 32, ;; Align in bits
1705 i64 64, ;; Offset in bits
1706 i32 0, ;; Flags
1707 metadata !5 ;; Derived From type
1708}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1709
1710;;
1711;; Define the array of fields used by the composite type Color.
1712;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1713!3 = metadata !{metadata !4, metadata !6, metadata !7}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1714</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1715</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1716
1717</div>
1718
1719<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1720<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1721 <a name="ccxx_enumeration_types">C/C++ enumeration types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1722</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1723
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1724<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1725
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1726<p>Given the following as an example of C/C++ enumeration type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1727
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1728<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1729<pre>
1730enum Trees {
1731 Spruce = 100,
1732 Oak = 200,
1733 Maple = 300
1734};
1735</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1736</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1737
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1738<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1739
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1740<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1741<pre>
1742;;
1743;; Define composite type for enum Trees
1744;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1745!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1746 i32 524292, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1747 metadata !1, ;; Context
1748 metadata !"Trees", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1749 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1750 i32 1, ;; Line number
1751 i64 32, ;; Size in bits
1752 i64 32, ;; Align in bits
1753 i64 0, ;; Offset in bits
1754 i32 0, ;; Flags
1755 null, ;; Derived From type
1756 metadata !3, ;; Elements
1757 i32 0 ;; Runtime language
1758}
Devang Patel2a610c72009-08-25 05:24:07 +0000[diff] [blame]1759
Devang Patel82459882009-08-26 05:01:18 +0000[diff] [blame]1760;;
1761;; Define the array of enumerators used by composite type Trees.
1762;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1763!3 = metadata !{metadata !4, metadata !5, metadata !6}
1764
1765;;
1766;; Define Spruce enumerator.
1767;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1768!4 = metadata !{i32 524328, metadata !"Spruce", i64 100}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1769
1770;;
1771;; Define Oak enumerator.
1772;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1773!5 = metadata !{i32 524328, metadata !"Oak", i64 200}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1774
1775;;
1776;; Define Maple enumerator.
1777;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1778!6 = metadata !{i32 524328, metadata !"Maple", i64 300}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1779
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1780</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1781</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1782
1783</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1784
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1785</div>
1786
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1787<!-- *********************************************************************** -->
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1788
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1789<hr>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1790<address>
1791 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1792 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1793 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1794 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1795
1796 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]1797 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1798 Last modified: $Date$
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1799</address>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1800
1801</body>
1802</html>