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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>
Devang Patel6ac5b162011-11-15 22:59:54 +0000[diff] [blame]56 <li><a href="#llvmdwarfextension">LLVM Dwarf Extensions</a>
57 <ol>
58 <li><a href="#objcproperty">Debugging Information Extension
59 for Objective C Properties</a></li>
60 <ul>
61 <li><a href="#objcpropertyintroduction">Introduction</a></li>
62 <li><a href="#objcpropertyproposal">Proposal</a></li>
63 <li><a href="#objcpropertynewattributes">New DWARF Attributes</a></li>
64 <li><a href="#objcpropertynewconstants">New DWARF Constants</a></li>
65 </ul>
66
67 </ol>
68 </li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]69</ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]70</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]71<td class="right">
Misha Brukmane849a1a2004-05-12 21:26:16 +0000[diff] [blame]72<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247"
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]73height="369">
74</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]75</tr></table>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]76
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]77<div class="doc_author">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]78 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
Jim Laskeyc760a922007-03-14 19:32:21 +0000[diff] [blame]79 and <a href="mailto:jlaskey@mac.com">Jim Laskey</a></p>
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]80</div>
81
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]82
83<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]84<h2><a name="introduction">Introduction</a></h2>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]85<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]86
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]87<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]88
89<p>This document is the central repository for all information pertaining to
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]90 debug information in LLVM. It describes the <a href="#format">actual format
91 that the LLVM debug information</a> takes, which is useful for those
92 interested in creating front-ends or dealing directly with the information.
Chris Lattner8ad2f982009-07-18 21:47:15 +0000[diff] [blame]93 Further, this document provides specific examples of what debug information
Chris Lattner89940752011-01-18 06:12:10 +0000[diff] [blame]94 for C/C++ looks like.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]95
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]96<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]97<h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]98 <a name="phil">Philosophy behind LLVM debugging information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]99</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]100
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]101<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]102
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]103<p>The idea of the LLVM debugging information is to capture how the important
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]104 pieces of the source-language's Abstract Syntax Tree map onto LLVM code.
105 Several design aspects have shaped the solution that appears here. The
106 important ones are:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]107
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]108<ul>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]109 <li>Debugging information should have very little impact on the rest of the
110 compiler. No transformations, analyses, or code generators should need to
111 be modified because of debugging information.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]112
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]113 <li>LLVM optimizations should interact in <a href="#debugopt">well-defined and
114 easily described ways</a> with the debugging information.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]115
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]116 <li>Because LLVM is designed to support arbitrary programming languages,
117 LLVM-to-LLVM tools should not need to know anything about the semantics of
118 the source-level-language.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]119
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]120 <li>Source-level languages are often <b>widely</b> different from one another.
121 LLVM should not put any restrictions of the flavor of the source-language,
122 and the debugging information should work with any language.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]123
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]124 <li>With code generator support, it should be possible to use an LLVM compiler
125 to compile a program to native machine code and standard debugging
126 formats. This allows compatibility with traditional machine-code level
127 debuggers, like GDB or DBX.</li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]128</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]129
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]130<p>The approach used by the LLVM implementation is to use a small set
131 of <a href="#format_common_intrinsics">intrinsic functions</a> to define a
132 mapping between LLVM program objects and the source-level objects. The
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]133 description of the source-level program is maintained in LLVM metadata
134 in an <a href="#ccxx_frontend">implementation-defined format</a>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]135 (the C/C++ front-end currently uses working draft 7 of
136 the <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3
137 standard</a>).</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]138
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]139<p>When a program is being debugged, a debugger interacts with the user and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]140 turns the stored debug information into source-language specific information.
141 As such, a debugger must be aware of the source-language, and is thus tied to
142 a specific language or family of languages.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]143
144</div>
145
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]146<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]147<h3>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]148 <a name="consumers">Debug information consumers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]149</h3>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]150
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]151<div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]152
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]153<p>The role of debug information is to provide meta information normally
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]154 stripped away during the compilation process. This meta information provides
155 an LLVM user a relationship between generated code and the original program
156 source code.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]157
Chris Lattnerc3107782010-04-05 04:11:11 +0000[diff] [blame]158<p>Currently, debug information is consumed by DwarfDebug to produce dwarf
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]159 information used by the gdb debugger. Other targets could use the same
160 information to produce stabs or other debug forms.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]161
162<p>It would also be reasonable to use debug information to feed profiling tools
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]163 for analysis of generated code, or, tools for reconstructing the original
164 source from generated code.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]165
166<p>TODO - expound a bit more.</p>
167
168</div>
169
170<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]171<h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]172 <a name="debugopt">Debugging optimized code</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]173</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]174
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]175<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]176
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]177<p>An extremely high priority of LLVM debugging information is to make it
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]178 interact well with optimizations and analysis. In particular, the LLVM debug
179 information provides the following guarantees:</p>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]180
181<ul>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]182 <li>LLVM debug information <b>always provides information to accurately read
183 the source-level state of the program</b>, regardless of which LLVM
184 optimizations have been run, and without any modification to the
185 optimizations themselves. However, some optimizations may impact the
186 ability to modify the current state of the program with a debugger, such
187 as setting program variables, or calling functions that have been
188 deleted.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]189
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]190 <li>As desired, LLVM optimizations can be upgraded to be aware of the LLVM
191 debugging information, allowing them to update the debugging information
192 as they perform aggressive optimizations. This means that, with effort,
193 the LLVM optimizers could optimize debug code just as well as non-debug
194 code.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]195
Devang Patele0bdc592011-05-31 17:45:27 +0000[diff] [blame]196 <li>LLVM debug information does not prevent optimizations from
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]197 happening (for example inlining, basic block reordering/merging/cleanup,
Devang Patelf729e912011-05-31 18:06:14 +0000[diff] [blame]198 tail duplication, etc).</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]199
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]200 <li>LLVM debug information is automatically optimized along with the rest of
201 the program, using existing facilities. For example, duplicate
202 information is automatically merged by the linker, and unused information
203 is automatically removed.</li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]204</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]205
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]206<p>Basically, the debug information allows you to compile a program with
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]207 "<tt>-O0 -g</tt>" and get full debug information, allowing you to arbitrarily
208 modify the program as it executes from a debugger. Compiling a program with
209 "<tt>-O3 -g</tt>" gives you full debug information that is always available
210 and accurate for reading (e.g., you get accurate stack traces despite tail
211 call elimination and inlining), but you might lose the ability to modify the
212 program and call functions where were optimized out of the program, or
213 inlined away completely.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]214
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]215<p><a href="TestingGuide.html#quicktestsuite">LLVM test suite</a> provides a
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]216 framework to test optimizer's handling of debugging information. It can be
217 run like this:</p>
Devang Patela5c05aa2008-11-21 19:35:57 +0000[diff] [blame]218
219<div class="doc_code">
220<pre>
221% cd llvm/projects/test-suite/MultiSource/Benchmarks # or some other level
222% make TEST=dbgopt
223</pre>
224</div>
225
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]226<p>This will test impact of debugging information on optimization passes. If
227 debugging information influences optimization passes then it will be reported
228 as a failure. See <a href="TestingGuide.html">TestingGuide</a> for more
229 information on LLVM test infrastructure and how to run various tests.</p>
Devang Patela5c05aa2008-11-21 19:35:57 +0000[diff] [blame]230
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]231</div>
232
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]233</div>
234
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]235<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]236<h2>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]237 <a name="format">Debugging information format</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]238</h2>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]239<!-- *********************************************************************** -->
240
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]241<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]242
243<p>LLVM debugging information has been carefully designed to make it possible
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]244 for the optimizer to optimize the program and debugging information without
245 necessarily having to know anything about debugging information. In
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]246 particular, the use of metadata avoids duplicated debugging information from
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]247 the beginning, and the global dead code elimination pass automatically
248 deletes debugging information for a function if it decides to delete the
249 function. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]250
251<p>To do this, most of the debugging information (descriptors for types,
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]252 variables, functions, source files, etc) is inserted by the language
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]253 front-end in the form of LLVM metadata. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]254
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]255<p>Debug information is designed to be agnostic about the target debugger and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]256 debugging information representation (e.g. DWARF/Stabs/etc). It uses a
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]257 generic pass to decode the information that represents variables, types,
258 functions, namespaces, etc: this allows for arbitrary source-language
259 semantics and type-systems to be used, as long as there is a module
260 written for the target debugger to interpret the information. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]261
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]262<p>To provide basic functionality, the LLVM debugger does have to make some
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]263 assumptions about the source-level language being debugged, though it keeps
264 these to a minimum. The only common features that the LLVM debugger assumes
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]265 exist are <a href="#format_files">source files</a>,
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]266 and <a href="#format_global_variables">program objects</a>. These abstract
267 objects are used by a debugger to form stack traces, show information about
268 local variables, etc.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]269
270<p>This section of the documentation first describes the representation aspects
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]271 common to any source-language. The <a href="#ccxx_frontend">next section</a>
272 describes the data layout conventions used by the C and C++ front-ends.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]273
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]274<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]275<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]276 <a name="debug_info_descriptors">Debug information descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]277</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]278
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]279<div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]280
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]281<p>In consideration of the complexity and volume of debug information, LLVM
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]282 provides a specification for well formed debug descriptors. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]283
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]284<p>Consumers of LLVM debug information expect the descriptors for program
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]285 objects to start in a canonical format, but the descriptors can include
286 additional information appended at the end that is source-language
287 specific. All LLVM debugging information is versioned, allowing backwards
288 compatibility in the case that the core structures need to change in some
289 way. Also, all debugging information objects start with a tag to indicate
290 what type of object it is. The source-language is allowed to define its own
291 objects, by using unreserved tag numbers. We recommend using with tags in
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]292 the range 0x1000 through 0x2000 (there is a defined enum DW_TAG_user_base =
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]293 0x1000.)</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]294
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]295<p>The fields of debug descriptors used internally by LLVM
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]296 are restricted to only the simple data types <tt>i32</tt>, <tt>i1</tt>,
297 <tt>float</tt>, <tt>double</tt>, <tt>mdstring</tt> and <tt>mdnode</tt>. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]298
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]299<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]300<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]301!1 = metadata !{
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]302 i32, ;; A tag
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]303 ...
304}
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]305</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]306</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]307
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]308<p><a name="LLVMDebugVersion">The first field of a descriptor is always an
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]309 <tt>i32</tt> containing a tag value identifying the content of the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]310 descriptor. The remaining fields are specific to the descriptor. The values
311 of tags are loosely bound to the tag values of DWARF information entries.
312 However, that does not restrict the use of the information supplied to DWARF
313 targets. To facilitate versioning of debug information, the tag is augmented
Nick Lewyckyf3379da2011-07-25 21:13:23 +0000[diff] [blame]314 with the current debug version (LLVMDebugVersion = 8 &lt;&lt; 16 or
315 0x80000 or 524288.)</a></p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]316
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]317<p>The details of the various descriptors follow.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]318
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]319<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]320<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]321 <a name="format_compile_units">Compile unit descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]322</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]323
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]324<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]325
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]326<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]327<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]328!0 = metadata !{
329 i32, ;; Tag = 17 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
330 ;; (DW_TAG_compile_unit)
331 i32, ;; Unused field.
332 i32, ;; DWARF language identifier (ex. DW_LANG_C89)
333 metadata, ;; Source file name
334 metadata, ;; Source file directory (includes trailing slash)
335 metadata ;; Producer (ex. "4.0.1 LLVM (LLVM research group)")
336 i1, ;; True if this is a main compile unit.
337 i1, ;; True if this is optimized.
338 metadata, ;; Flags
339 i32 ;; Runtime version
Devang Patel9b4a2ac2011-09-09 17:07:15 +0000[diff] [blame]340 metadata ;; List of enums types
341 metadata ;; List of retained types
342 metadata ;; List of subprograms
343 metadata ;; List of global variables
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]344}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]345</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]346</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]347
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]348<p>These descriptors contain a source language ID for the file (we use the DWARF
349 3.0 ID numbers, such as <tt>DW_LANG_C89</tt>, <tt>DW_LANG_C_plus_plus</tt>,
350 <tt>DW_LANG_Cobol74</tt>, etc), three strings describing the filename,
351 working directory of the compiler, and an identifier string for the compiler
352 that produced it.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]353
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]354<p>Compile unit descriptors provide the root context for objects declared in a
Devang Patel464f4ef2011-05-03 16:18:28 +0000[diff] [blame]355 specific compilation unit. File descriptors are defined using this context.
356 These descriptors are collected by a named metadata
Devang Patel9b4a2ac2011-09-09 17:07:15 +0000[diff] [blame]357 <tt>!llvm.dbg.cu</tt>. Compile unit descriptor keeps track of subprograms,
358 global variables and type information.
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]359
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]360</div>
361
362<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]363<h4>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]364 <a name="format_files">File descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]365</h4>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]366
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]367<div>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]368
369<div class="doc_code">
370<pre>
371!0 = metadata !{
372 i32, ;; Tag = 41 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
373 ;; (DW_TAG_file_type)
374 metadata, ;; Source file name
375 metadata, ;; Source file directory (includes trailing slash)
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]376 metadata ;; Unused
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]377}
378</pre>
379</div>
380
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]381<p>These descriptors contain information for a file. Global variables and top
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]382 level functions would be defined using this context.k File descriptors also
383 provide context for source line correspondence. </p>
384
385<p>Each input file is encoded as a separate file descriptor in LLVM debugging
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]386 information output. </p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]387
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]388</div>
389
390<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]391<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]392 <a name="format_global_variables">Global variable descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]393</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]394
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]395<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]396
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]397<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]398<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]399!1 = metadata !{
400 i32, ;; Tag = 52 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
401 ;; (DW_TAG_variable)
402 i32, ;; Unused field.
403 metadata, ;; Reference to context descriptor
404 metadata, ;; Name
405 metadata, ;; Display name (fully qualified C++ name)
406 metadata, ;; MIPS linkage name (for C++)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]407 metadata, ;; Reference to file where defined
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]408 i32, ;; Line number where defined
409 metadata, ;; Reference to type descriptor
410 i1, ;; True if the global is local to compile unit (static)
411 i1, ;; True if the global is defined in the compile unit (not extern)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]412 {}* ;; Reference to the global variable
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]413}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]414</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]415</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]416
417<p>These descriptors provide debug information about globals variables. The
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]418provide details such as name, type and where the variable is defined. All
419global variables are collected by named metadata <tt>!llvm.dbg.gv</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]420
421</div>
422
423<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]424<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]425 <a name="format_subprograms">Subprogram descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]426</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]427
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]428<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]429
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]430<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]431<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]432!2 = metadata !{
433 i32, ;; Tag = 46 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
434 ;; (DW_TAG_subprogram)
435 i32, ;; Unused field.
436 metadata, ;; Reference to context descriptor
437 metadata, ;; Name
438 metadata, ;; Display name (fully qualified C++ name)
439 metadata, ;; MIPS linkage name (for C++)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]440 metadata, ;; Reference to file where defined
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]441 i32, ;; Line number where defined
442 metadata, ;; Reference to type descriptor
443 i1, ;; True if the global is local to compile unit (static)
Devang Patel5e06bb82011-04-22 23:10:17 +0000[diff] [blame]444 i1, ;; True if the global is defined in the compile unit (not extern)
445 i32, ;; Virtuality, e.g. dwarf::DW_VIRTUALITY__virtual
446 i32, ;; Index into a virtual function
Devang Patel80ecc152010-06-04 22:49:55 +0000[diff] [blame]447 metadata, ;; indicates which base type contains the vtable pointer for the
448 ;; derived class
Devang Patel473f95f2011-12-16 17:50:04 +0000[diff] [blame^]449 i32, ;; Flags - Artifical, Private, Protected, Explicit, Prototyped.
Devang Patel5e06bb82011-04-22 23:10:17 +0000[diff] [blame]450 i1, ;; isOptimized
451 Function *,;; Pointer to LLVM function
452 metadata, ;; Lists function template parameters
453 metadata ;; Function declaration descriptor
Devang Patel93d39be2011-08-19 23:28:12 +0000[diff] [blame]454 metadata ;; List of function variables
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]455}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]456</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]457</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]458
459<p>These descriptors provide debug information about functions, methods and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]460 subprograms. They provide details such as name, return types and the source
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]461 location where the subprogram is defined.
462 All subprogram descriptors are collected by a named metadata
463 <tt>!llvm.dbg.sp</tt>.
464</p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]465
466</div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]467
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]468<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]469<h4>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]470 <a name="format_blocks">Block descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]471</h4>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]472
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]473<div>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]474
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]475<div class="doc_code">
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]476<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]477!3 = metadata !{
Devang Patelc79dda22010-10-04 16:51:59 +0000[diff] [blame]478 i32, ;; Tag = 11 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block)
Devang Patel7f271fc2010-10-01 22:45:00 +0000[diff] [blame]479 metadata,;; Reference to context descriptor
480 i32, ;; Line number
Devang Patel90d81f12011-03-08 16:25:29 +0000[diff] [blame]481 i32, ;; Column number
482 metadata,;; Reference to source file
483 i32 ;; Unique ID to identify blocks from a template function
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]484}
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]485</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]486</div>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]487
Eric Christopher6618a242011-10-11 22:59:11 +0000[diff] [blame]488<p>This descriptor provides debug information about nested blocks within a
Devang Patel7f271fc2010-10-01 22:45:00 +0000[diff] [blame]489 subprogram. The line number and column numbers are used to dinstinguish
490 two lexical blocks at same depth. </p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]491
Eric Christopher6618a242011-10-11 22:59:11 +0000[diff] [blame]492<div class="doc_code">
493<pre>
494!3 = metadata !{
495 i32, ;; Tag = 11 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block)
496 metadata ;; Reference to the scope we're annotating with a file change
497 metadata,;; Reference to the file the scope is enclosed in.
498}
499</pre>
500</div>
501
502<p>This descriptor provides a wrapper around a lexical scope to handle file
503 changes in the middle of a lexical block.</p>
504
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]505</div>
506
507<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]508<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]509 <a name="format_basic_type">Basic type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]510</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]511
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]512<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]513
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]514<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]515<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]516!4 = metadata !{
517 i32, ;; Tag = 36 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
518 ;; (DW_TAG_base_type)
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]519 metadata, ;; Reference to context
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]520 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]521 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]522 i32, ;; Line number where defined (may be 0)
523 i64, ;; Size in bits
524 i64, ;; Alignment in bits
525 i64, ;; Offset in bits
526 i32, ;; Flags
527 i32 ;; DWARF type encoding
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]528}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]529</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]530</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]531
532<p>These descriptors define primitive types used in the code. Example int, bool
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]533 and float. The context provides the scope of the type, which is usually the
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]534 top level. Since basic types are not usually user defined the context
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]535 and line number can be left as NULL and 0. The size, alignment and offset
536 are expressed in bits and can be 64 bit values. The alignment is used to
537 round the offset when embedded in a
538 <a href="#format_composite_type">composite type</a> (example to keep float
539 doubles on 64 bit boundaries.) The offset is the bit offset if embedded in
540 a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]541
542<p>The type encoding provides the details of the type. The values are typically
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]543 one of the following:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]544
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]545<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]546<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]547DW_ATE_address = 1
548DW_ATE_boolean = 2
549DW_ATE_float = 4
550DW_ATE_signed = 5
551DW_ATE_signed_char = 6
552DW_ATE_unsigned = 7
553DW_ATE_unsigned_char = 8
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]554</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]555</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]556
557</div>
558
559<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]560<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]561 <a name="format_derived_type">Derived type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]562</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]563
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]564<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]565
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]566<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]567<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]568!5 = metadata !{
569 i32, ;; Tag (see below)
570 metadata, ;; Reference to context
571 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]572 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]573 i32, ;; Line number where defined (may be 0)
Devang Patel0ffd10b2010-10-01 19:19:30 +0000[diff] [blame]574 i64, ;; Size in bits
575 i64, ;; Alignment in bits
576 i64, ;; Offset in bits
Devang Patele9db5e22011-04-16 00:11:51 +0000[diff] [blame]577 metadata, ;; Reference to type derived from
578 metadata, ;; (optional) Name of the Objective C property assoicated with
579 ;; Objective-C an ivar
580 metadata, ;; (optional) Name of the Objective C property getter selector.
581 metadata, ;; (optional) Name of the Objective C property setter selector.
582 i32 ;; (optional) Objective C property attributes.
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]583}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]584</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]585</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]586
587<p>These descriptors are used to define types derived from other types. The
588value of the tag varies depending on the meaning. The following are possible
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]589tag values:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]590
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]591<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]592<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]593DW_TAG_formal_parameter = 5
594DW_TAG_member = 13
595DW_TAG_pointer_type = 15
596DW_TAG_reference_type = 16
597DW_TAG_typedef = 22
598DW_TAG_const_type = 38
599DW_TAG_volatile_type = 53
600DW_TAG_restrict_type = 55
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]601</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]602</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]603
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]604<p><tt>DW_TAG_member</tt> is used to define a member of
605 a <a href="#format_composite_type">composite type</a>
606 or <a href="#format_subprograms">subprogram</a>. The type of the member is
607 the <a href="#format_derived_type">derived
608 type</a>. <tt>DW_TAG_formal_parameter</tt> is used to define a member which
609 is a formal argument of a subprogram.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]610
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]611<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]612
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]613<p><tt>DW_TAG_pointer_type</tt>,<tt>DW_TAG_reference_type</tt>,
614 <tt>DW_TAG_const_type</tt>, <tt>DW_TAG_volatile_type</tt>
615 and <tt>DW_TAG_restrict_type</tt> are used to qualify
616 the <a href="#format_derived_type">derived type</a>. </p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]617
618<p><a href="#format_derived_type">Derived type</a> location can be determined
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]619 from the context and line number. The size, alignment and offset are
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]620 expressed in bits and can be 64 bit values. The alignment is used to round
621 the offset when embedded in a <a href="#format_composite_type">composite
622 type</a> (example to keep float doubles on 64 bit boundaries.) The offset is
623 the bit offset if embedded in a <a href="#format_composite_type">composite
624 type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]625
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]626<p>Note that the <tt>void *</tt> type is expressed as a type derived from NULL.
627</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]628
629</div>
630
631<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]632<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]633 <a name="format_composite_type">Composite type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]634</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]635
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]636<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]637
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]638<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]639<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]640!6 = metadata !{
641 i32, ;; Tag (see below)
642 metadata, ;; Reference to context
643 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]644 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]645 i32, ;; Line number where defined (may be 0)
646 i64, ;; Size in bits
647 i64, ;; Alignment in bits
648 i64, ;; Offset in bits
649 i32, ;; Flags
650 metadata, ;; Reference to type derived from
651 metadata, ;; Reference to array of member descriptors
652 i32 ;; Runtime languages
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]653}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]654</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]655</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]656
657<p>These descriptors are used to define types that are composed of 0 or more
658elements. The value of the tag varies depending on the meaning. The following
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]659are possible tag values:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]660
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]661<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]662<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]663DW_TAG_array_type = 1
664DW_TAG_enumeration_type = 4
665DW_TAG_structure_type = 19
666DW_TAG_union_type = 23
667DW_TAG_vector_type = 259
Bruno Cardoso Lopesd80ddc02009-05-29 17:08:57 +0000[diff] [blame]668DW_TAG_subroutine_type = 21
669DW_TAG_inheritance = 28
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]670</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]671</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]672
Jim Laskeyf8a01a92006-06-15 20:51:43 +0000[diff] [blame]673<p>The vector flag indicates that an array type is a native packed vector.</p>
674
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]675<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]676 (tag = <tt>DW_TAG_vector_type</tt>) are <a href="#format_subrange">subrange
677 descriptors</a>, each representing the range of subscripts at that level of
678 indexing.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]679
680<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]681 <a href="#format_enumeration">enumerator descriptors</a>, each representing
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]682 the definition of enumeration value for the set. All enumeration type
683 descriptors are collected by named metadata <tt>!llvm.dbg.enum</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]684
685<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]686 = <tt>DW_TAG_union_type</tt>) types are any one of
687 the <a href="#format_basic_type">basic</a>,
688 <a href="#format_derived_type">derived</a>
689 or <a href="#format_composite_type">composite</a> type descriptors, each
690 representing a field member of the structure or union.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]691
Jim Laskey4a9df242006-08-21 21:21:06 +0000[diff] [blame]692<p>For C++ classes (tag = <tt>DW_TAG_structure_type</tt>), member descriptors
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]693 provide information about base classes, static members and member
694 functions. If a member is a <a href="#format_derived_type">derived type
695 descriptor</a> and has a tag of <tt>DW_TAG_inheritance</tt>, then the type
696 represents a base class. If the member of is
697 a <a href="#format_global_variables">global variable descriptor</a> then it
698 represents a static member. And, if the member is
699 a <a href="#format_subprograms">subprogram descriptor</a> then it represents
700 a member function. For static members and member
701 functions, <tt>getName()</tt> returns the members link or the C++ mangled
702 name. <tt>getDisplayName()</tt> the simplied version of the name.</p>
Jim Laskey4a9df242006-08-21 21:21:06 +0000[diff] [blame]703
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]704<p>The first member of subroutine (tag = <tt>DW_TAG_subroutine_type</tt>) type
705 elements is the return type for the subroutine. The remaining elements are
706 the formal arguments to the subroutine.</p>
Jim Laskey094ee722006-06-20 21:13:20 +0000[diff] [blame]707
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]708<p><a href="#format_composite_type">Composite type</a> location can be
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]709 determined from the context and line number. The size, alignment and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]710 offset are expressed in bits and can be 64 bit values. The alignment is used
711 to round the offset when embedded in
712 a <a href="#format_composite_type">composite type</a> (as an example, to keep
713 float doubles on 64 bit boundaries.) The offset is the bit offset if embedded
714 in a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]715
716</div>
717
718<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]719<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]720 <a name="format_subrange">Subrange descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]721</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]722
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]723<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]724
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]725<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]726<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]727!42 = metadata !{
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]728 i32, ;; Tag = 33 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subrange_type)
729 i64, ;; Low value
730 i64 ;; High value
731}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]732</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]733</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]734
735<p>These descriptors are used to define ranges of array subscripts for an array
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]736 <a href="#format_composite_type">composite type</a>. The low value defines
737 the lower bounds typically zero for C/C++. The high value is the upper
738 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]739 > high the array bounds are not included in generated debugging information.
740</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]741
742</div>
743
744<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]745<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]746 <a name="format_enumeration">Enumerator descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]747</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]748
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]749<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]750
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]751<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]752<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]753!6 = metadata !{
754 i32, ;; Tag = 40 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
755 ;; (DW_TAG_enumerator)
756 metadata, ;; Name
757 i64 ;; Value
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]758}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]759</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]760</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]761
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]762<p>These descriptors are used to define members of an
763 enumeration <a href="#format_composite_type">composite type</a>, it
764 associates the name to the value.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]765
766</div>
767
768<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]769<h4>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]770 <a name="format_variables">Local variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]771</h4>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]772
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]773<div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]774
775<div class="doc_code">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]776<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]777!7 = metadata !{
778 i32, ;; Tag (see below)
779 metadata, ;; Context
780 metadata, ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]781 metadata, ;; Reference to file where defined
Devang Patela83688f2011-03-08 16:29:40 +0000[diff] [blame]782 i32, ;; 24 bit - Line number where defined
783 ;; 8 bit - Argument number. 1 indicates 1st argument.
Devang Patel0a2a3062011-07-27 18:14:50 +0000[diff] [blame]784 metadata, ;; Type descriptor
785 i32, ;; flags
786 metadata ;; (optional) Reference to inline location
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]787}
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]788</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]789</div>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]790
791<p>These descriptors are used to define variables local to a sub program. The
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]792 value of the tag depends on the usage of the variable:</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]793
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]794<div class="doc_code">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]795<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]796DW_TAG_auto_variable = 256
797DW_TAG_arg_variable = 257
798DW_TAG_return_variable = 258
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]799</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]800</div>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]801
802<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]803 argument variable is any variable that appears as a formal argument to the
804 function. A return variable is used to track the result of a function and
805 has no source correspondent.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]806
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame]807<p>The context is either the subprogram or block where the variable is defined.
Devang Patel94c7ddb2011-08-16 22:09:43 +0000[diff] [blame]808 Name the source variable name. Context and line indicate where the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]809 variable was defined. Type descriptor defines the declared type of the
810 variable.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]811
812</div>
813
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]814</div>
815
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]816<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]817<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]818 <a name="format_common_intrinsics">Debugger intrinsic functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]819</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]820
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]821<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]822
823<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]824 provide debug information at various points in generated code.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]825
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]826<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]827<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]828 <a name="format_common_declare">llvm.dbg.declare</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]829</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]830
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]831<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]832<pre>
Devang Patel4c7c0c62010-10-01 19:22:16 +0000[diff] [blame]833 void %<a href="#format_common_declare">llvm.dbg.declare</a>(metadata, metadata)
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]834</pre>
835
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame]836<p>This intrinsic provides information about a local element (ex. variable.) The
NAKAMURA Takumi4d6deb02011-04-09 09:51:57 +0000[diff] [blame]837 first argument is metadata holding alloca for the variable. The
Devang Patele136e502011-02-01 17:22:12 +0000[diff] [blame]838 second argument is metadata containing description of the variable. </p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]839</div>
840
841<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]842<h4>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]843 <a name="format_common_value">llvm.dbg.value</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]844</h4>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]845
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]846<div>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]847<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]848 void %<a href="#format_common_value">llvm.dbg.value</a>(metadata, i64, metadata)
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]849</pre>
850
851<p>This intrinsic provides information when a user source variable is set to a
852 new value. The first argument is the new value (wrapped as metadata). The
853 second argument is the offset in the user source variable where the new value
Devang Patele136e502011-02-01 17:22:12 +0000[diff] [blame]854 is written. The third argument is metadata containing description of the
855 user source variable. </p>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]856</div>
857
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]858</div>
859
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]860<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]861<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]862 <a name="format_common_lifetime">Object lifetimes and scoping</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]863</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]864
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]865<div>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]866<p>In many languages, the local variables in functions can have their lifetimes
867 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]868 for example, variables are only live (readable and writable) within the
869 source block that they are defined in. In functional languages, values are
870 only readable after they have been defined. Though this is a very obvious
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]871 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]872 scoping in this sense, and does not want to be tied to a language's scoping
873 rules.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]874
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]875<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]876 llvm instructions to encode line number and scoping information. Consider
877 the following C fragment, for example:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]878
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]879<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]880<pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8811. void foo() {
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8822. int X = 21;
8833. int Y = 22;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8844. {
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8855. int Z = 23;
8866. Z = X;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8877. }
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8888. X = Y;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8899. }
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]890</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]891</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]892
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]893<p>Compiled to LLVM, this function would be represented like this:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]894
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]895<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]896<pre>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]897define void @foo() nounwind ssp {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]898entry:
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]899 %X = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
900 %Y = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
901 %Z = alloca i32, align 4 ; &lt;i32*&gt; [#uses=3]
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]902 %0 = bitcast i32* %X to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]903 call void @llvm.dbg.declare(metadata !{i32 * %X}, metadata !0), !dbg !7
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]904 store i32 21, i32* %X, !dbg !8
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]905 %1 = bitcast i32* %Y to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]906 call void @llvm.dbg.declare(metadata !{i32 * %Y}, metadata !9), !dbg !10
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]907 store i32 22, i32* %Y, !dbg !11
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]908 %2 = bitcast i32* %Z to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]909 call void @llvm.dbg.declare(metadata !{i32 * %Z}, metadata !12), !dbg !14
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]910 store i32 23, i32* %Z, !dbg !15
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]911 %tmp = load i32* %X, !dbg !16 ; &lt;i32&gt; [#uses=1]
912 %tmp1 = load i32* %Y, !dbg !16 ; &lt;i32&gt; [#uses=1]
913 %add = add nsw i32 %tmp, %tmp1, !dbg !16 ; &lt;i32&gt; [#uses=1]
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]914 store i32 %add, i32* %Z, !dbg !16
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]915 %tmp2 = load i32* %Y, !dbg !17 ; &lt;i32&gt; [#uses=1]
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]916 store i32 %tmp2, i32* %X, !dbg !17
917 ret void, !dbg !18
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]918}
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]919
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]920declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]921
922!0 = metadata !{i32 459008, metadata !1, metadata !"X",
923 metadata !3, i32 2, metadata !6}; [ DW_TAG_auto_variable ]
924!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
925!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo", metadata !"foo",
926 metadata !"foo", metadata !3, i32 1, metadata !4,
927 i1 false, i1 true}; [DW_TAG_subprogram ]
928!3 = metadata !{i32 458769, i32 0, i32 12, metadata !"foo.c",
929 metadata !"/private/tmp", metadata !"clang 1.1", i1 true,
930 i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
931!4 = metadata !{i32 458773, metadata !3, metadata !"", null, i32 0, i64 0, i64 0,
932 i64 0, i32 0, null, metadata !5, i32 0}; [DW_TAG_subroutine_type ]
933!5 = metadata !{null}
934!6 = metadata !{i32 458788, metadata !3, metadata !"int", metadata !3, i32 0,
935 i64 32, i64 32, i64 0, i32 0, i32 5}; [DW_TAG_base_type ]
936!7 = metadata !{i32 2, i32 7, metadata !1, null}
937!8 = metadata !{i32 2, i32 3, metadata !1, null}
938!9 = metadata !{i32 459008, metadata !1, metadata !"Y", metadata !3, i32 3,
939 metadata !6}; [ DW_TAG_auto_variable ]
940!10 = metadata !{i32 3, i32 7, metadata !1, null}
941!11 = metadata !{i32 3, i32 3, metadata !1, null}
942!12 = metadata !{i32 459008, metadata !13, metadata !"Z", metadata !3, i32 5,
943 metadata !6}; [ DW_TAG_auto_variable ]
944!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
945!14 = metadata !{i32 5, i32 9, metadata !13, null}
946!15 = metadata !{i32 5, i32 5, metadata !13, null}
947!16 = metadata !{i32 6, i32 5, metadata !13, null}
948!17 = metadata !{i32 8, i32 3, metadata !1, null}
949!18 = metadata !{i32 9, i32 1, metadata !2, null}
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]950</pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]951</div>
952
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]953<p>This example illustrates a few important details about LLVM debugging
954 information. In particular, it shows how the <tt>llvm.dbg.declare</tt>
955 intrinsic and location information, which are attached to an instruction,
956 are applied together to allow a debugger to analyze the relationship between
957 statements, variable definitions, and the code used to implement the
958 function.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]959
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]960<div class="doc_code">
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]961<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]962call void @llvm.dbg.declare(metadata, metadata !0), !dbg !7
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]963</pre>
964</div>
965
966<p>The first intrinsic
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]967 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]968 encodes debugging information for the variable <tt>X</tt>. The metadata
969 <tt>!dbg !7</tt> attached to the intrinsic provides scope information for the
970 variable <tt>X</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]971
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]972<div class="doc_code">
973<pre>
974!7 = metadata !{i32 2, i32 7, metadata !1, null}
975!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
976!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo",
977 metadata !"foo", metadata !"foo", metadata !3, i32 1,
978 metadata !4, i1 false, i1 true}; [DW_TAG_subprogram ]
979</pre>
980</div>
981
982<p>Here <tt>!7</tt> is metadata providing location information. It has four
983 fields: line number, column number, scope, and original scope. The original
984 scope represents inline location if this instruction is inlined inside a
985 caller, and is null otherwise. In this example, scope is encoded by
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]986 <tt>!1</tt>. <tt>!1</tt> represents a lexical block inside the scope
987 <tt>!2</tt>, where <tt>!2</tt> is a
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]988 <a href="#format_subprograms">subprogram descriptor</a>. This way the
989 location information attached to the intrinsics indicates that the
990 variable <tt>X</tt> is declared at line number 2 at a function level scope in
991 function <tt>foo</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]992
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]993<p>Now lets take another example.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]994
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]995<div class="doc_code">
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]996<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]997call void @llvm.dbg.declare(metadata, metadata !12), !dbg !14
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]998</pre>
999</div>
1000
1001<p>The second intrinsic
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]1002 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]1003 encodes debugging information for variable <tt>Z</tt>. The metadata
1004 <tt>!dbg !14</tt> attached to the intrinsic provides scope information for
1005 the variable <tt>Z</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1006
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]1007<div class="doc_code">
1008<pre>
1009!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
1010!14 = metadata !{i32 5, i32 9, metadata !13, null}
1011</pre>
1012</div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1013
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]1014<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]1015 column number 9 inside of lexical scope <tt>!13</tt>. The lexical scope
1016 itself resides inside of lexical scope <tt>!1</tt> described above.</p>
1017
1018<p>The scope information attached with each instruction provides a
1019 straightforward way to find instructions covered by a scope.</p>
1020
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1021</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1022
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1023</div>
1024
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1025<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1026<h2>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1027 <a name="ccxx_frontend">C/C++ front-end specific debug information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1028</h2>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]1029<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1030
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1031<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1032
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1033<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]1034 that is effectively identical
1035 to <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3.0</a> in
1036 terms of information content. This allows code generators to trivially
1037 support native debuggers by generating standard dwarf information, and
1038 contains enough information for non-dwarf targets to translate it as
1039 needed.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1040
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1041<p>This section describes the forms used to represent C and C++ programs. Other
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1042 languages could pattern themselves after this (which itself is tuned to
1043 representing programs in the same way that DWARF 3 does), or they could
1044 choose to provide completely different forms if they don't fit into the DWARF
1045 model. As support for debugging information gets added to the various LLVM
1046 source-language front-ends, the information used should be documented
1047 here.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1048
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1049<p>The following sections provide examples of various C/C++ constructs and the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1050 debug information that would best describe those constructs.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1051
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1052<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1053<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1054 <a name="ccxx_compile_units">C/C++ source file information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1055</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1056
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1057<div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1058
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1059<p>Given the source files <tt>MySource.cpp</tt> and <tt>MyHeader.h</tt> located
1060 in the directory <tt>/Users/mine/sources</tt>, the following code:</p>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1061
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1062<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1063<pre>
1064#include "MyHeader.h"
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1065
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1066int main(int argc, char *argv[]) {
1067 return 0;
1068}
1069</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1070</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1071
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1072<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1073
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1074<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1075<pre>
1076...
1077;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1078;; Define the compile unit for the main source file "/Users/mine/sources/MySource.cpp".
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1079;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1080!2 = metadata !{
1081 i32 524305, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1082 i32 0, ;; Unused
1083 i32 4, ;; Language Id
1084 metadata !"MySource.cpp",
1085 metadata !"/Users/mine/sources",
1086 metadata !"4.2.1 (Based on Apple Inc. build 5649) (LLVM build 00)",
1087 i1 true, ;; Main Compile Unit
1088 i1 false, ;; Optimized compile unit
1089 metadata !"", ;; Compiler flags
1090 i32 0} ;; Runtime version
1091
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1092;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1093;; Define the file for the file "/Users/mine/sources/MySource.cpp".
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1094;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1095!1 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1096 i32 524329, ;; Tag
1097 metadata !"MySource.cpp",
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1098 metadata !"/Users/mine/sources",
Devang Patel9fea9c22010-07-13 16:53:20 +0000[diff] [blame]1099 metadata !2 ;; Compile unit
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1100}
1101
1102;;
1103;; Define the file for the file "/Users/mine/sources/Myheader.h"
1104;;
1105!3 = metadata !{
1106 i32 524329, ;; Tag
1107 metadata !"Myheader.h"
1108 metadata !"/Users/mine/sources",
Devang Patel9fea9c22010-07-13 16:53:20 +0000[diff] [blame]1109 metadata !2 ;; Compile unit
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1110}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1111
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1112...
1113</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1114</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1115
Devang Pateld98ec5f2010-03-26 19:08:36 +0000[diff] [blame]1116<p>llvm::Instruction provides easy access to metadata attached with an
1117instruction. One can extract line number information encoded in LLVM IR
1118using <tt>Instruction::getMetadata()</tt> and
1119<tt>DILocation::getLineNumber()</tt>.
1120<pre>
1121 if (MDNode *N = I->getMetadata("dbg")) { // Here I is an LLVM instruction
1122 DILocation Loc(N); // DILocation is in DebugInfo.h
1123 unsigned Line = Loc.getLineNumber();
1124 StringRef File = Loc.getFilename();
1125 StringRef Dir = Loc.getDirectory();
1126 }
1127</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1128</div>
1129
1130<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1131<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1132 <a name="ccxx_global_variable">C/C++ global variable information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1133</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1134
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1135<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1136
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1137<p>Given an integer global variable declared as follows:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1138
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1139<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1140<pre>
1141int MyGlobal = 100;
1142</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1143</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1144
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1145<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1146
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1147<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1148<pre>
1149;;
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1150;; Define the global itself.
1151;;
1152%MyGlobal = global int 100
1153...
1154;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1155;; List of debug info of globals
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1156;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1157!llvm.dbg.gv = !{!0}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1158
1159;;
1160;; Define the global variable descriptor. Note the reference to the global
1161;; variable anchor and the global variable itself.
1162;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1163!0 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1164 i32 524340, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1165 i32 0, ;; Unused
1166 metadata !1, ;; Context
1167 metadata !"MyGlobal", ;; Name
1168 metadata !"MyGlobal", ;; Display Name
1169 metadata !"MyGlobal", ;; Linkage Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1170 metadata !3, ;; Compile Unit
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1171 i32 1, ;; Line Number
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1172 metadata !4, ;; Type
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1173 i1 false, ;; Is a local variable
1174 i1 true, ;; Is this a definition
1175 i32* @MyGlobal ;; The global variable
1176}
1177
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1178;;
1179;; Define the basic type of 32 bit signed integer. Note that since int is an
1180;; intrinsic type the source file is NULL and line 0.
1181;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1182!4 = metadata !{
1183 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1184 metadata !1, ;; Context
1185 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1186 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1187 i32 0, ;; Line number
1188 i64 32, ;; Size in Bits
1189 i64 32, ;; Align in Bits
1190 i64 0, ;; Offset in Bits
1191 i32 0, ;; Flags
1192 i32 5 ;; Encoding
1193}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1194
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1195</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1196</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1197
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1198</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1199
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1200<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1201<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1202 <a name="ccxx_subprogram">C/C++ function information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1203</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1204
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1205<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1206
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1207<p>Given a function declared as follows:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1208
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1209<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1210<pre>
1211int main(int argc, char *argv[]) {
1212 return 0;
1213}
1214</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1215</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1216
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1217<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1218
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1219<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1220<pre>
1221;;
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1222;; Define the anchor for subprograms. Note that the second field of the
1223;; anchor is 46, which is the same as the tag for subprograms
1224;; (46 = DW_TAG_subprogram.)
1225;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1226!6 = metadata !{
1227 i32 524334, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1228 i32 0, ;; Unused
1229 metadata !1, ;; Context
1230 metadata !"main", ;; Name
1231 metadata !"main", ;; Display name
1232 metadata !"main", ;; Linkage name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1233 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1234 i32 1, ;; Line number
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1235 metadata !4, ;; Type
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1236 i1 false, ;; Is local
Devang Patelda194752011-04-05 22:52:06 +0000[diff] [blame]1237 i1 true, ;; Is definition
1238 i32 0, ;; Virtuality attribute, e.g. pure virtual function
1239 i32 0, ;; Index into virtual table for C++ methods
1240 i32 0, ;; Type that holds virtual table.
1241 i32 0, ;; Flags
1242 i1 false, ;; True if this function is optimized
1243 Function *, ;; Pointer to llvm::Function
1244 null ;; Function template parameters
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1245}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1246;;
1247;; Define the subprogram itself.
1248;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1249define i32 @main(i32 %argc, i8** %argv) {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1250...
1251}
1252</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1253</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1254
1255</div>
1256
1257<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1258<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1259 <a name="ccxx_basic_types">C/C++ basic types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1260</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1261
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1262<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1263
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1264<p>The following are the basic type descriptors for C/C++ core types:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1265
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1266<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1267<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1268 <a name="ccxx_basic_type_bool">bool</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1269</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1270
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1271<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1272
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1273<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1274<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1275!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1276 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1277 metadata !1, ;; Context
1278 metadata !"bool", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1279 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1280 i32 0, ;; Line number
1281 i64 8, ;; Size in Bits
1282 i64 8, ;; Align in Bits
1283 i64 0, ;; Offset in Bits
1284 i32 0, ;; Flags
1285 i32 2 ;; Encoding
1286}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1287</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1288</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1289
1290</div>
1291
1292<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1293<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1294 <a name="ccxx_basic_char">char</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1295</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1296
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1297<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1298
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1299<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1300<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1301!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1302 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1303 metadata !1, ;; Context
1304 metadata !"char", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1305 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1306 i32 0, ;; Line number
1307 i64 8, ;; Size in Bits
1308 i64 8, ;; Align in Bits
1309 i64 0, ;; Offset in Bits
1310 i32 0, ;; Flags
1311 i32 6 ;; Encoding
1312}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1313</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1314</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1315
1316</div>
1317
1318<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1319<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1320 <a name="ccxx_basic_unsigned_char">unsigned char</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1321</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1322
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1323<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1324
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1325<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1326<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1327!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1328 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1329 metadata !1, ;; Context
1330 metadata !"unsigned char",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1331 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1332 i32 0, ;; Line number
1333 i64 8, ;; Size in Bits
1334 i64 8, ;; Align in Bits
1335 i64 0, ;; Offset in Bits
1336 i32 0, ;; Flags
1337 i32 8 ;; Encoding
1338}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1339</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1340</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1341
1342</div>
1343
1344<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1345<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1346 <a name="ccxx_basic_short">short</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1347</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1348
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1349<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1350
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1351<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1352<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1353!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1354 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1355 metadata !1, ;; Context
1356 metadata !"short int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1357 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1358 i32 0, ;; Line number
1359 i64 16, ;; Size in Bits
1360 i64 16, ;; Align in Bits
1361 i64 0, ;; Offset in Bits
1362 i32 0, ;; Flags
1363 i32 5 ;; Encoding
1364}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1365</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1366</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1367
1368</div>
1369
1370<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1371<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1372 <a name="ccxx_basic_unsigned_short">unsigned short</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1373</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1374
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1375<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1376
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1377<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1378<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1379!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1380 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1381 metadata !1, ;; Context
1382 metadata !"short unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1383 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1384 i32 0, ;; Line number
1385 i64 16, ;; Size in Bits
1386 i64 16, ;; Align in Bits
1387 i64 0, ;; Offset in Bits
1388 i32 0, ;; Flags
1389 i32 7 ;; Encoding
1390}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1391</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1392</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1393
1394</div>
1395
1396<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1397<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1398 <a name="ccxx_basic_int">int</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1399</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1400
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1401<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1402
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1403<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1404<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1405!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1406 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1407 metadata !1, ;; Context
1408 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1409 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1410 i32 0, ;; Line number
1411 i64 32, ;; Size in Bits
1412 i64 32, ;; Align in Bits
1413 i64 0, ;; Offset in Bits
1414 i32 0, ;; Flags
1415 i32 5 ;; Encoding
1416}
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1417</pre></div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1418
1419</div>
1420
1421<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1422<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1423 <a name="ccxx_basic_unsigned_int">unsigned int</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1424</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1425
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1426<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1427
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1428<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1429<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1430!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1431 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1432 metadata !1, ;; Context
1433 metadata !"unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1434 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1435 i32 0, ;; Line number
1436 i64 32, ;; Size in Bits
1437 i64 32, ;; Align in Bits
1438 i64 0, ;; Offset in Bits
1439 i32 0, ;; Flags
1440 i32 7 ;; Encoding
1441}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1442</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1443</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1444
1445</div>
1446
1447<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1448<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1449 <a name="ccxx_basic_long_long">long long</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1450</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1451
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1452<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1453
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1454<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1455<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1456!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1457 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1458 metadata !1, ;; Context
1459 metadata !"long long int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1460 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1461 i32 0, ;; Line number
1462 i64 64, ;; Size in Bits
1463 i64 64, ;; Align in Bits
1464 i64 0, ;; Offset in Bits
1465 i32 0, ;; Flags
1466 i32 5 ;; Encoding
1467}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1468</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1469</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1470
1471</div>
1472
1473<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1474<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1475 <a name="ccxx_basic_unsigned_long_long">unsigned long long</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1476</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1477
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1478<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1479
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1480<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1481<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1482!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1483 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1484 metadata !1, ;; Context
1485 metadata !"long long unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1486 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1487 i32 0, ;; Line number
1488 i64 64, ;; Size in Bits
1489 i64 64, ;; Align in Bits
1490 i64 0, ;; Offset in Bits
1491 i32 0, ;; Flags
1492 i32 7 ;; Encoding
1493}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1494</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1495</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1496
1497</div>
1498
1499<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1500<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1501 <a name="ccxx_basic_float">float</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1502</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1503
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1504<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1505
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1506<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1507<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1508!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1509 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1510 metadata !1, ;; Context
1511 metadata !"float",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1512 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1513 i32 0, ;; Line number
1514 i64 32, ;; Size in Bits
1515 i64 32, ;; Align in Bits
1516 i64 0, ;; Offset in Bits
1517 i32 0, ;; Flags
1518 i32 4 ;; Encoding
1519}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1520</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1521</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1522
1523</div>
1524
1525<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1526<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1527 <a name="ccxx_basic_double">double</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1528</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1529
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1530<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1531
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1532<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1533<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1534!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1535 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1536 metadata !1, ;; Context
1537 metadata !"double",;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1538 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1539 i32 0, ;; Line number
1540 i64 64, ;; Size in Bits
1541 i64 64, ;; Align in Bits
1542 i64 0, ;; Offset in Bits
1543 i32 0, ;; Flags
1544 i32 4 ;; Encoding
1545}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1546</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1547</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1548
1549</div>
1550
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1551</div>
1552
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1553<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1554<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1555 <a name="ccxx_derived_types">C/C++ derived types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1556</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1557
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1558<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1559
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1560<p>Given the following as an example of C/C++ derived type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1561
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1562<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1563<pre>
1564typedef const int *IntPtr;
1565</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1566</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1567
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1568<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1569
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1570<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1571<pre>
1572;;
1573;; Define the typedef "IntPtr".
1574;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1575!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1576 i32 524310, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1577 metadata !1, ;; Context
1578 metadata !"IntPtr", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1579 metadata !3, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1580 i32 0, ;; Line number
1581 i64 0, ;; Size in bits
1582 i64 0, ;; Align in bits
1583 i64 0, ;; Offset in bits
1584 i32 0, ;; Flags
1585 metadata !4 ;; Derived From type
1586}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1587
1588;;
1589;; Define the pointer type.
1590;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1591!4 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1592 i32 524303, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1593 metadata !1, ;; Context
1594 metadata !"", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1595 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1596 i32 0, ;; Line number
1597 i64 64, ;; Size in bits
1598 i64 64, ;; Align in bits
1599 i64 0, ;; Offset in bits
1600 i32 0, ;; Flags
1601 metadata !5 ;; Derived From type
1602}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1603;;
1604;; Define the const type.
1605;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1606!5 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1607 i32 524326, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1608 metadata !1, ;; Context
1609 metadata !"", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1610 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1611 i32 0, ;; Line number
1612 i64 32, ;; Size in bits
1613 i64 32, ;; Align in bits
1614 i64 0, ;; Offset in bits
1615 i32 0, ;; Flags
1616 metadata !6 ;; Derived From type
1617}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1618;;
1619;; Define the int type.
1620;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1621!6 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1622 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1623 metadata !1, ;; Context
1624 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1625 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1626 i32 0, ;; Line number
1627 i64 32, ;; Size in bits
1628 i64 32, ;; Align in bits
1629 i64 0, ;; Offset in bits
1630 i32 0, ;; Flags
1631 5 ;; Encoding
1632}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1633</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1634</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1635
1636</div>
1637
1638<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1639<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1640 <a name="ccxx_composite_types">C/C++ struct/union types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1641</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1642
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1643<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1644
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1645<p>Given the following as an example of C/C++ struct type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1646
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1647<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1648<pre>
1649struct Color {
1650 unsigned Red;
1651 unsigned Green;
1652 unsigned Blue;
1653};
1654</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1655</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1656
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1657<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1658
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1659<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1660<pre>
1661;;
1662;; Define basic type for unsigned int.
1663;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1664!5 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1665 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1666 metadata !1, ;; Context
1667 metadata !"unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1668 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1669 i32 0, ;; Line number
1670 i64 32, ;; Size in Bits
1671 i64 32, ;; Align in Bits
1672 i64 0, ;; Offset in Bits
1673 i32 0, ;; Flags
1674 i32 7 ;; Encoding
1675}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1676;;
1677;; Define composite type for struct Color.
1678;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1679!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1680 i32 524307, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1681 metadata !1, ;; Context
1682 metadata !"Color", ;; Name
1683 metadata !1, ;; Compile unit
1684 i32 1, ;; Line number
1685 i64 96, ;; Size in bits
1686 i64 32, ;; Align in bits
1687 i64 0, ;; Offset in bits
1688 i32 0, ;; Flags
1689 null, ;; Derived From
1690 metadata !3, ;; Elements
1691 i32 0 ;; Runtime Language
1692}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1693
1694;;
1695;; Define the Red field.
1696;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1697!4 = 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 !"Red", ;; 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 2, ;; Line number
1703 i64 32, ;; Size in bits
1704 i64 32, ;; Align in bits
1705 i64 0, ;; 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 Green field.
1712;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1713!6 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1714 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1715 metadata !1, ;; Context
1716 metadata !"Green", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1717 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1718 i32 3, ;; Line number
1719 i64 32, ;; Size in bits
1720 i64 32, ;; Align in bits
1721 i64 32, ;; Offset in bits
1722 i32 0, ;; Flags
1723 metadata !5 ;; Derived From type
1724}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1725
1726;;
1727;; Define the Blue field.
1728;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1729!7 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1730 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1731 metadata !1, ;; Context
1732 metadata !"Blue", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1733 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1734 i32 4, ;; Line number
1735 i64 32, ;; Size in bits
1736 i64 32, ;; Align in bits
1737 i64 64, ;; Offset in bits
1738 i32 0, ;; Flags
1739 metadata !5 ;; Derived From type
1740}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1741
1742;;
1743;; Define the array of fields used by the composite type Color.
1744;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1745!3 = metadata !{metadata !4, metadata !6, metadata !7}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1746</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1747</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1748
1749</div>
1750
1751<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1752<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1753 <a name="ccxx_enumeration_types">C/C++ enumeration types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1754</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1755
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1756<div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1757
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1758<p>Given the following as an example of C/C++ enumeration type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1759
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1760<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1761<pre>
1762enum Trees {
1763 Spruce = 100,
1764 Oak = 200,
1765 Maple = 300
1766};
1767</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1768</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1769
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1770<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1771
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1772<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1773<pre>
1774;;
1775;; Define composite type for enum Trees
1776;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1777!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1778 i32 524292, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1779 metadata !1, ;; Context
1780 metadata !"Trees", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1781 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1782 i32 1, ;; Line number
1783 i64 32, ;; Size in bits
1784 i64 32, ;; Align in bits
1785 i64 0, ;; Offset in bits
1786 i32 0, ;; Flags
1787 null, ;; Derived From type
1788 metadata !3, ;; Elements
1789 i32 0 ;; Runtime language
1790}
Devang Patel2a610c72009-08-25 05:24:07 +0000[diff] [blame]1791
Devang Patel82459882009-08-26 05:01:18 +0000[diff] [blame]1792;;
1793;; Define the array of enumerators used by composite type Trees.
1794;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1795!3 = metadata !{metadata !4, metadata !5, metadata !6}
1796
1797;;
1798;; Define Spruce enumerator.
1799;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1800!4 = metadata !{i32 524328, metadata !"Spruce", i64 100}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1801
1802;;
1803;; Define Oak enumerator.
1804;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1805!5 = metadata !{i32 524328, metadata !"Oak", i64 200}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1806
1807;;
1808;; Define Maple enumerator.
1809;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1810!6 = metadata !{i32 524328, metadata !"Maple", i64 300}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1811
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1812</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1813</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1814
1815</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1816
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1817</div>
1818
Devang Patel6ac5b162011-11-15 22:59:54 +0000[diff] [blame]1819
1820<!-- *********************************************************************** -->
1821<h2>
1822 <a name="llvmdwarfextension">Debugging information format</a>
1823</h2>
1824<!-- *********************************************************************** -->
1825<div>
1826<!-- ======================================================================= -->
1827<h3>
1828 <a name="objcproperty">Debugging Information Extension for Objective C
1829Properties</a></li>
1830</h3>
1831<div>
1832<!-- *********************************************************************** -->
1833<h4>
1834 <a name="objcpropertyintroduction">Introduction</a>
1835</h4>
1836<!-- *********************************************************************** -->
1837
1838<div>
1839<p>Objective C provides a simpler way to declare and define accessor methods
1840using declared properties. The language provides features to declare a
1841property and to let compiler synthesize accessor methods.
1842</p>
1843
1844<p>The debugger lets developer inspect Objective C interfaces and their
1845instance variables and class variables. However, the debugger does not know
1846anything about the properties defined in Objective C interfaces. The debugger
1847consumes information generated by compiler in DWARF format. The format does
1848not support encoding of Objective C properties. This proposal describes DWARF
1849extensions to encode Objective C properties, which the debugger can use to let
1850developers inspect Objective C properties.
1851</p>
1852
1853</div>
1854
1855
1856<!-- *********************************************************************** -->
1857<h4>
1858 <a name="objcpropertyproposal">Proposal</a>
1859</h4>
1860<!-- *********************************************************************** -->
1861
1862<div>
1863<p>Objective C properties are always backed by an instance variable. The
1864instance variables backing properties are identified using
1865DW_AT_APPLE_property_name attribute. The instance variables with this
1866attribute may not have data location attributes. The location of instance
1867variables is determined by debugger only after consulting Objective C runtime.
1868</p>
1869
1870<div class="doc_code">
1871<pre>
1872@interface I1 {
1873 int n2;
1874}
1875
1876@property p1;
1877@property p2;
1878@end
1879
1880@implementation I1
1881@synthesize p1;
1882@synthesize p2 = n2;
1883@end
1884
1885
1886TAG_structure_type [7] *
1887 AT_APPLE_runtime_class( 0x10 )
1888 AT_name( "I1" )
1889 AT_decl_file( "Objc_Property.m" )
1890 AT_decl_line( 3 )
1891
1892 TAG_member [8]
1893 AT_name( "p1" )
1894 AT_APPLE_property_name(“p1”)
1895 AT_type( {0x00000147} ( int ) )
1896
1897 TAG_member [8]
1898 AT_name( "n2" )
1899 AT_APPLE_property_name(“p2”)
1900 AT_type( {0x00000147} ( int ) )
1901</pre>
1902</div>
1903
1904<p> Developers can decorate a property with attributes which are encoded using
1905DW_AT_APPLE_property_attribute.
1906</p>
1907
1908<div class="doc_code">
1909<pre>
1910@property (readonly, nonatomic) int pr;
1911
1912
1913TAG_member [8]
1914 AT_name(“pr”)
1915 AT_APPLE_property_name(“pr”)
1916 AT_type ( {0x00000147} (int) )
1917 AT_APPLE_property_attribute (DW_APPLE_PROPERTY_readonly, DW_APPLE_PROPERTY_nonatomic)
1918</pre>
1919</div>
1920
1921<p> The setter and getter method names are attached to the property using
1922DW_AT_APPLE_property_setter and DW_AT_APPLE_property_getter attributes.
1923</p>
1924<div class="doc_code">
1925<pre>
1926@interface I1
1927@property (setter=myOwnP3Setter:) int p3;
1928-(void)myOwnP3Setter:(int)a;
1929@end
1930
1931@implementation I1
1932@synthesize p3;
1933-(void)myOwnP3Setter:(int)a{ }
1934@end
1935
19360x000003bd: TAG_structure_type [7] *
1937 AT_APPLE_runtime_class( 0x10 )
1938 AT_name( "I1" )
1939 AT_decl_file( "Objc_Property.m" )
1940 AT_decl_line( 3 )
19410x000003f3: TAG_member [8]
1942 AT_name( "p3" )
1943 AT_APPLE_property_name(“p3”)
1944 AT_APPLE_property_setter(“myOwnP3Setter:”)
1945 AT_type( {0x00000147} ( int ) )
1946</pre>
1947</div>
1948
1949</div>
1950
1951<!-- *********************************************************************** -->
1952<h4>
1953 <a name="objcpropertynewattributes">New DWARF Attributes</a>
1954</h4>
1955<!-- *********************************************************************** -->
1956
1957<div>
1958<table border="1" cellspacing="0">
1959 <tr>
1960 <th width=200 >Attribute</th>
1961 <th width=200 >Value</th>
1962 <th width=200 >Classes</th>
1963 </tr>
1964 <tr>
1965 <td width=200 >DW_AT_APPLE_property_name</td>
1966 <td width=200 >0x3fe8</td>
1967 <td width=200 >String</td>
1968 </tr>
1969 <tr>
1970 <td width=200 >DW_AT_APPLE_property_getter</td>
1971 <td width=200 >0x3fe9</td>
1972 <td width=200 >String</td>
1973 </tr>
1974 <tr>
1975 <td width=200 >DW_AT_APPLE_property_setter</td>
1976 <td width=200 >0x3fea</td>
1977 <td width=200 >String</td>
1978 </tr>
1979 <tr>
1980 <td width=200 >DW_AT_APPLE_property_attribute</td>
1981 <td width=200 >0x3feb</td>
1982 <td width=200 >Constant</td>
1983 </tr>
1984</table>
1985
1986</div>
1987
1988<!-- *********************************************************************** -->
1989<h4>
1990 <a name="objcpropertynewconstants">New DWARF Constants</a>
1991</h4>
1992<!-- *********************************************************************** -->
1993
1994<div>
1995<table border="1" cellspacing="0">
1996 <tr>
1997 <th width=200 >Name</th>
1998 <th width=200 >Value</th>
1999 </tr>
2000 <tr>
2001 <td width=200 >DW_AT_APPLE_PROPERTY_readonly</td>
2002 <td width=200 >0x1</td>
2003 </tr>
2004 <tr>
2005 <td width=200 >DW_AT_APPLE_PROPERTY_readwrite</td>
2006 <td width=200 >0x2</td>
2007 </tr>
2008 <tr>
2009 <td width=200 >DW_AT_APPLE_PROPERTY_assign</td>
2010 <td width=200 >0x4</td>
2011 </tr>
2012 <tr>
2013 <td width=200 >DW_AT_APPLE_PROPERTY_retain</td>
2014 <td width=200 >0x8</td>
2015 </tr>
2016 <tr>
2017 <td width=200 >DW_AT_APPLE_PROPERTY_copy</td>
2018 <td width=200 >0x10</td>
2019 </tr>
2020 <tr>
2021 <td width=200 >DW_AT_APPLE_PROPERTY_nonatomic</td>
2022 <td width=200 >0x20</td>
2023 </tr>
2024</table>
2025
2026</div>
2027</div>
2028</div>
2029
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]2030<!-- *********************************************************************** -->
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Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]2032<hr>
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2039 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
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