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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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10
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]11<h1>Source Level Debugging with LLVM</h1>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]12
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]13<table class="layout" style="width:100%">
14 <tr class="layout">
15 <td class="left">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]16<ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]17 <li><a href="#introduction">Introduction</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]18 <ol>
19 <li><a href="#phil">Philosophy behind LLVM debugging information</a></li>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]20 <li><a href="#consumers">Debug information consumers</a></li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]21 <li><a href="#debugopt">Debugging optimized code</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]22 </ol></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]23 <li><a href="#format">Debugging information format</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]24 <ol>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]25 <li><a href="#debug_info_descriptors">Debug information descriptors</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]26 <ul>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]27 <li><a href="#format_compile_units">Compile unit descriptors</a></li>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]28 <li><a href="#format_files">File descriptors</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]29 <li><a href="#format_global_variables">Global variable descriptors</a></li>
30 <li><a href="#format_subprograms">Subprogram descriptors</a></li>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]31 <li><a href="#format_blocks">Block descriptors</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]32 <li><a href="#format_basic_type">Basic type descriptors</a></li>
33 <li><a href="#format_derived_type">Derived type descriptors</a></li>
34 <li><a href="#format_composite_type">Composite type descriptors</a></li>
35 <li><a href="#format_subrange">Subrange descriptors</a></li>
36 <li><a href="#format_enumeration">Enumerator descriptors</a></li>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]37 <li><a href="#format_variables">Local variables</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]38 </ul></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]39 <li><a href="#format_common_intrinsics">Debugger intrinsic functions</a>
40 <ul>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]41 <li><a href="#format_common_declare">llvm.dbg.declare</a></li>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]42 <li><a href="#format_common_value">llvm.dbg.value</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]43 </ul></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]44 </ol></li>
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]45 <li><a href="#format_common_lifetime">Object lifetimes and scoping</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]46 <li><a href="#ccxx_frontend">C/C++ front-end specific debug information</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]47 <ol>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]48 <li><a href="#ccxx_compile_units">C/C++ source file information</a></li>
49 <li><a href="#ccxx_global_variable">C/C++ global variable information</a></li>
50 <li><a href="#ccxx_subprogram">C/C++ function information</a></li>
51 <li><a href="#ccxx_basic_types">C/C++ basic types</a></li>
52 <li><a href="#ccxx_derived_types">C/C++ derived types</a></li>
53 <li><a href="#ccxx_composite_types">C/C++ struct/union types</a></li>
54 <li><a href="#ccxx_enumeration_types">C/C++ enumeration types</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]55 </ol></li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]56</ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]57</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]58<td class="right">
Misha Brukmane849a1a2004-05-12 21:26:16 +0000[diff] [blame]59<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247"
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]60height="369">
61</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]62</tr></table>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]63
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]64<div class="doc_author">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]65 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
Jim Laskeyc760a922007-03-14 19:32:21 +0000[diff] [blame]66 and <a href="mailto:jlaskey@mac.com">Jim Laskey</a></p>
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]67</div>
68
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]69
70<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]71<h2><a name="introduction">Introduction</a></h2>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]72<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]73
74<div class="doc_text">
75
76<p>This document is the central repository for all information pertaining to
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]77 debug information in LLVM. It describes the <a href="#format">actual format
78 that the LLVM debug information</a> takes, which is useful for those
79 interested in creating front-ends or dealing directly with the information.
Chris Lattner8ad2f982009-07-18 21:47:15 +0000[diff] [blame]80 Further, this document provides specific examples of what debug information
Chris Lattner89940752011-01-18 06:12:10 +0000[diff] [blame]81 for C/C++ looks like.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]82
83</div>
84
85<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]86<h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]87 <a name="phil">Philosophy behind LLVM debugging information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]88</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]89
90<div class="doc_text">
91
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]92<p>The idea of the LLVM debugging information is to capture how the important
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]93 pieces of the source-language's Abstract Syntax Tree map onto LLVM code.
94 Several design aspects have shaped the solution that appears here. The
95 important ones are:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]96
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]97<ul>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]98 <li>Debugging information should have very little impact on the rest of the
99 compiler. No transformations, analyses, or code generators should need to
100 be modified because of debugging information.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]101
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]102 <li>LLVM optimizations should interact in <a href="#debugopt">well-defined and
103 easily described ways</a> with the debugging information.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]104
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]105 <li>Because LLVM is designed to support arbitrary programming languages,
106 LLVM-to-LLVM tools should not need to know anything about the semantics of
107 the source-level-language.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]108
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]109 <li>Source-level languages are often <b>widely</b> different from one another.
110 LLVM should not put any restrictions of the flavor of the source-language,
111 and the debugging information should work with any language.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]112
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]113 <li>With code generator support, it should be possible to use an LLVM compiler
114 to compile a program to native machine code and standard debugging
115 formats. This allows compatibility with traditional machine-code level
116 debuggers, like GDB or DBX.</li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]117</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]118
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]119<p>The approach used by the LLVM implementation is to use a small set
120 of <a href="#format_common_intrinsics">intrinsic functions</a> to define a
121 mapping between LLVM program objects and the source-level objects. The
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]122 description of the source-level program is maintained in LLVM metadata
123 in an <a href="#ccxx_frontend">implementation-defined format</a>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]124 (the C/C++ front-end currently uses working draft 7 of
125 the <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3
126 standard</a>).</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]127
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]128<p>When a program is being debugged, a debugger interacts with the user and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]129 turns the stored debug information into source-language specific information.
130 As such, a debugger must be aware of the source-language, and is thus tied to
131 a specific language or family of languages.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]132
133</div>
134
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]135<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]136<h3>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]137 <a name="consumers">Debug information consumers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]138</h3>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]139
140<div class="doc_text">
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]141
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]142<p>The role of debug information is to provide meta information normally
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]143 stripped away during the compilation process. This meta information provides
144 an LLVM user a relationship between generated code and the original program
145 source code.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]146
Chris Lattnerc3107782010-04-05 04:11:11 +0000[diff] [blame]147<p>Currently, debug information is consumed by DwarfDebug to produce dwarf
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]148 information used by the gdb debugger. Other targets could use the same
149 information to produce stabs or other debug forms.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]150
151<p>It would also be reasonable to use debug information to feed profiling tools
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]152 for analysis of generated code, or, tools for reconstructing the original
153 source from generated code.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]154
155<p>TODO - expound a bit more.</p>
156
157</div>
158
159<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]160<h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]161 <a name="debugopt">Debugging optimized code</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]162</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]163
164<div class="doc_text">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]165
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]166<p>An extremely high priority of LLVM debugging information is to make it
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]167 interact well with optimizations and analysis. In particular, the LLVM debug
168 information provides the following guarantees:</p>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]169
170<ul>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]171 <li>LLVM debug information <b>always provides information to accurately read
172 the source-level state of the program</b>, regardless of which LLVM
173 optimizations have been run, and without any modification to the
174 optimizations themselves. However, some optimizations may impact the
175 ability to modify the current state of the program with a debugger, such
176 as setting program variables, or calling functions that have been
177 deleted.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]178
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]179 <li>LLVM optimizations gracefully interact with debugging information. If
180 they are not aware of debug information, they are automatically disabled
181 as necessary in the cases that would invalidate the debug info. This
182 retains the LLVM features, making it easy to write new
183 transformations.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]184
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]185 <li>As desired, LLVM optimizations can be upgraded to be aware of the LLVM
186 debugging information, allowing them to update the debugging information
187 as they perform aggressive optimizations. This means that, with effort,
188 the LLVM optimizers could optimize debug code just as well as non-debug
189 code.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]190
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]191 <li>LLVM debug information does not prevent many important optimizations from
192 happening (for example inlining, basic block reordering/merging/cleanup,
193 tail duplication, etc), further reducing the amount of the compiler that
194 eventually is "aware" of debugging information.</li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]195
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]196 <li>LLVM debug information is automatically optimized along with the rest of
197 the program, using existing facilities. For example, duplicate
198 information is automatically merged by the linker, and unused information
199 is automatically removed.</li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]200</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]201
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]202<p>Basically, the debug information allows you to compile a program with
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]203 "<tt>-O0 -g</tt>" and get full debug information, allowing you to arbitrarily
204 modify the program as it executes from a debugger. Compiling a program with
205 "<tt>-O3 -g</tt>" gives you full debug information that is always available
206 and accurate for reading (e.g., you get accurate stack traces despite tail
207 call elimination and inlining), but you might lose the ability to modify the
208 program and call functions where were optimized out of the program, or
209 inlined away completely.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]210
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]211<p><a href="TestingGuide.html#quicktestsuite">LLVM test suite</a> provides a
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]212 framework to test optimizer's handling of debugging information. It can be
213 run like this:</p>
Devang Patela5c05aa2008-11-21 19:35:57 +0000[diff] [blame]214
215<div class="doc_code">
216<pre>
217% cd llvm/projects/test-suite/MultiSource/Benchmarks # or some other level
218% make TEST=dbgopt
219</pre>
220</div>
221
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]222<p>This will test impact of debugging information on optimization passes. If
223 debugging information influences optimization passes then it will be reported
224 as a failure. See <a href="TestingGuide.html">TestingGuide</a> for more
225 information on LLVM test infrastructure and how to run various tests.</p>
Devang Patela5c05aa2008-11-21 19:35:57 +0000[diff] [blame]226
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]227</div>
228
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]229<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]230<h2>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]231 <a name="format">Debugging information format</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]232</h2>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]233<!-- *********************************************************************** -->
234
235<div class="doc_text">
236
237<p>LLVM debugging information has been carefully designed to make it possible
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]238 for the optimizer to optimize the program and debugging information without
239 necessarily having to know anything about debugging information. In
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]240 particular, the use of metadata avoids duplicated debugging information from
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]241 the beginning, and the global dead code elimination pass automatically
242 deletes debugging information for a function if it decides to delete the
243 function. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]244
245<p>To do this, most of the debugging information (descriptors for types,
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]246 variables, functions, source files, etc) is inserted by the language
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]247 front-end in the form of LLVM metadata. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]248
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]249<p>Debug information is designed to be agnostic about the target debugger and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]250 debugging information representation (e.g. DWARF/Stabs/etc). It uses a
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]251 generic pass to decode the information that represents variables, types,
252 functions, namespaces, etc: this allows for arbitrary source-language
253 semantics and type-systems to be used, as long as there is a module
254 written for the target debugger to interpret the information. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]255
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]256<p>To provide basic functionality, the LLVM debugger does have to make some
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]257 assumptions about the source-level language being debugged, though it keeps
258 these to a minimum. The only common features that the LLVM debugger assumes
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]259 exist are <a href="#format_files">source files</a>,
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]260 and <a href="#format_global_variables">program objects</a>. These abstract
261 objects are used by a debugger to form stack traces, show information about
262 local variables, etc.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]263
264<p>This section of the documentation first describes the representation aspects
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]265 common to any source-language. The <a href="#ccxx_frontend">next section</a>
266 describes the data layout conventions used by the C and C++ front-ends.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]267
268</div>
269
270<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]271<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]272 <a name="debug_info_descriptors">Debug information descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]273</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]274
275<div class="doc_text">
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]276
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]277<p>In consideration of the complexity and volume of debug information, LLVM
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]278 provides a specification for well formed debug descriptors. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]279
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]280<p>Consumers of LLVM debug information expect the descriptors for program
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]281 objects to start in a canonical format, but the descriptors can include
282 additional information appended at the end that is source-language
283 specific. All LLVM debugging information is versioned, allowing backwards
284 compatibility in the case that the core structures need to change in some
285 way. Also, all debugging information objects start with a tag to indicate
286 what type of object it is. The source-language is allowed to define its own
287 objects, by using unreserved tag numbers. We recommend using with tags in
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]288 the range 0x1000 through 0x2000 (there is a defined enum DW_TAG_user_base =
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]289 0x1000.)</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]290
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]291<p>The fields of debug descriptors used internally by LLVM
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]292 are restricted to only the simple data types <tt>i32</tt>, <tt>i1</tt>,
293 <tt>float</tt>, <tt>double</tt>, <tt>mdstring</tt> and <tt>mdnode</tt>. </p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]294
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]295<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]296<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]297!1 = metadata !{
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]298 i32, ;; A tag
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]299 ...
300}
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]301</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]302</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]303
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]304<p><a name="LLVMDebugVersion">The first field of a descriptor is always an
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]305 <tt>i32</tt> containing a tag value identifying the content of the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]306 descriptor. The remaining fields are specific to the descriptor. The values
307 of tags are loosely bound to the tag values of DWARF information entries.
308 However, that does not restrict the use of the information supplied to DWARF
309 targets. To facilitate versioning of debug information, the tag is augmented
Nick Lewycky655fd032010-03-31 07:50:17 +0000[diff] [blame]310 with the current debug version (LLVMDebugVersion = 8 &lt;&lt; 16 or 0x80000 or
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]311 524288.)</a></p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]312
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]313<p>The details of the various descriptors follow.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]314
315</div>
316
317<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]318<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]319 <a name="format_compile_units">Compile unit descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]320</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]321
322<div class="doc_text">
323
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]324<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]325<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]326!0 = metadata !{
327 i32, ;; Tag = 17 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
328 ;; (DW_TAG_compile_unit)
329 i32, ;; Unused field.
330 i32, ;; DWARF language identifier (ex. DW_LANG_C89)
331 metadata, ;; Source file name
332 metadata, ;; Source file directory (includes trailing slash)
333 metadata ;; Producer (ex. "4.0.1 LLVM (LLVM research group)")
334 i1, ;; True if this is a main compile unit.
335 i1, ;; True if this is optimized.
336 metadata, ;; Flags
337 i32 ;; Runtime version
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]338}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]339</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]340</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]341
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]342<p>These descriptors contain a source language ID for the file (we use the DWARF
343 3.0 ID numbers, such as <tt>DW_LANG_C89</tt>, <tt>DW_LANG_C_plus_plus</tt>,
344 <tt>DW_LANG_Cobol74</tt>, etc), three strings describing the filename,
345 working directory of the compiler, and an identifier string for the compiler
346 that produced it.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]347
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]348<p>Compile unit descriptors provide the root context for objects declared in a
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]349 specific compilation unit. File descriptors are defined using this context.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]350
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]351</div>
352
353<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]354<h4>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]355 <a name="format_files">File descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]356</h4>
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]357
358<div class="doc_text">
359
360<div class="doc_code">
361<pre>
362!0 = metadata !{
363 i32, ;; Tag = 41 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
364 ;; (DW_TAG_file_type)
365 metadata, ;; Source file name
366 metadata, ;; Source file directory (includes trailing slash)
367 metadata ;; Reference to compile unit where defined
368}
369</pre>
370</div>
371
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]372<p>These descriptors contain information for a file. Global variables and top
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]373 level functions would be defined using this context.k File descriptors also
374 provide context for source line correspondence. </p>
375
376<p>Each input file is encoded as a separate file descriptor in LLVM debugging
377 information output. Each file descriptor would be defined using a
378 compile unit. </p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]379
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]380</div>
381
382<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]383<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]384 <a name="format_global_variables">Global variable descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]385</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]386
387<div class="doc_text">
388
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]389<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]390<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]391!1 = metadata !{
392 i32, ;; Tag = 52 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
393 ;; (DW_TAG_variable)
394 i32, ;; Unused field.
395 metadata, ;; Reference to context descriptor
396 metadata, ;; Name
397 metadata, ;; Display name (fully qualified C++ name)
398 metadata, ;; MIPS linkage name (for C++)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]399 metadata, ;; Reference to file where defined
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]400 i32, ;; Line number where defined
401 metadata, ;; Reference to type descriptor
402 i1, ;; True if the global is local to compile unit (static)
403 i1, ;; True if the global is defined in the compile unit (not extern)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]404 {}* ;; Reference to the global variable
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]405}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]406</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]407</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]408
409<p>These descriptors provide debug information about globals variables. The
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]410provide details such as name, type and where the variable is defined. All
411global variables are collected by named metadata <tt>!llvm.dbg.gv</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]412
413</div>
414
415<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]416<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]417 <a name="format_subprograms">Subprogram descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]418</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]419
420<div class="doc_text">
421
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]422<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]423<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]424!2 = metadata !{
425 i32, ;; Tag = 46 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
426 ;; (DW_TAG_subprogram)
427 i32, ;; Unused field.
428 metadata, ;; Reference to context descriptor
429 metadata, ;; Name
430 metadata, ;; Display name (fully qualified C++ name)
431 metadata, ;; MIPS linkage name (for C++)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]432 metadata, ;; Reference to file where defined
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]433 i32, ;; Line number where defined
434 metadata, ;; Reference to type descriptor
435 i1, ;; True if the global is local to compile unit (static)
436 i1 ;; True if the global is defined in the compile unit (not extern)
Devang Patel80ecc152010-06-04 22:49:55 +0000[diff] [blame]437 i32 ;; Virtuality, e.g. dwarf::DW_VIRTUALITY__virtual
438 i32 ;; Index into a virtual function
439 metadata, ;; indicates which base type contains the vtable pointer for the
440 ;; derived class
441 i1 ;; isArtificial
442 i1 ;; isOptimized
443 Function *;; Pointer to LLVM function
Devang Patelda194752011-04-05 22:52:06 +0000[diff] [blame]444 metadata ;; Lists function template parameters
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]445}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]446</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]447</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]448
449<p>These descriptors provide debug information about functions, methods and
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]450 subprograms. They provide details such as name, return types and the source
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]451 location where the subprogram is defined.
452 All subprogram descriptors are collected by a named metadata
453 <tt>!llvm.dbg.sp</tt>.
454</p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]455
456</div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]457
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]458<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]459<h4>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]460 <a name="format_blocks">Block descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]461</h4>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]462
463<div class="doc_text">
464
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]465<div class="doc_code">
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]466<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]467!3 = metadata !{
Devang Patelc79dda22010-10-04 16:51:59 +0000[diff] [blame]468 i32, ;; Tag = 11 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block)
Devang Patel7f271fc2010-10-01 22:45:00 +0000[diff] [blame]469 metadata,;; Reference to context descriptor
470 i32, ;; Line number
Devang Patel90d81f12011-03-08 16:25:29 +0000[diff] [blame]471 i32, ;; Column number
472 metadata,;; Reference to source file
473 i32 ;; Unique ID to identify blocks from a template function
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]474}
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]475</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]476</div>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]477
478<p>These descriptors provide debug information about nested blocks within a
Devang Patel7f271fc2010-10-01 22:45:00 +0000[diff] [blame]479 subprogram. The line number and column numbers are used to dinstinguish
480 two lexical blocks at same depth. </p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]481
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]482</div>
483
484<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]485<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]486 <a name="format_basic_type">Basic type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]487</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]488
489<div class="doc_text">
490
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]491<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]492<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]493!4 = metadata !{
494 i32, ;; Tag = 36 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
495 ;; (DW_TAG_base_type)
496 metadata, ;; Reference to context (typically a compile unit)
497 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]498 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]499 i32, ;; Line number where defined (may be 0)
500 i64, ;; Size in bits
501 i64, ;; Alignment in bits
502 i64, ;; Offset in bits
503 i32, ;; Flags
504 i32 ;; DWARF type encoding
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]505}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]506</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]507</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]508
509<p>These descriptors define primitive types used in the code. Example int, bool
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]510 and float. The context provides the scope of the type, which is usually the
511 top level. Since basic types are not usually user defined the compile unit
512 and line number can be left as NULL and 0. The size, alignment and offset
513 are expressed in bits and can be 64 bit values. The alignment is used to
514 round the offset when embedded in a
515 <a href="#format_composite_type">composite type</a> (example to keep float
516 doubles on 64 bit boundaries.) The offset is the bit offset if embedded in
517 a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]518
519<p>The type encoding provides the details of the type. The values are typically
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]520 one of the following:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]521
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]522<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]523<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]524DW_ATE_address = 1
525DW_ATE_boolean = 2
526DW_ATE_float = 4
527DW_ATE_signed = 5
528DW_ATE_signed_char = 6
529DW_ATE_unsigned = 7
530DW_ATE_unsigned_char = 8
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]531</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]532</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]533
534</div>
535
536<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]537<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]538 <a name="format_derived_type">Derived type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]539</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]540
541<div class="doc_text">
542
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]543<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]544<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]545!5 = metadata !{
546 i32, ;; Tag (see below)
547 metadata, ;; Reference to context
548 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]549 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]550 i32, ;; Line number where defined (may be 0)
Devang Patel0ffd10b2010-10-01 19:19:30 +0000[diff] [blame]551 i64, ;; Size in bits
552 i64, ;; Alignment in bits
553 i64, ;; Offset in bits
Devang Patele9db5e22011-04-16 00:11:51 +0000[diff] [blame]554 metadata, ;; Reference to type derived from
555 metadata, ;; (optional) Name of the Objective C property assoicated with
556 ;; Objective-C an ivar
557 metadata, ;; (optional) Name of the Objective C property getter selector.
558 metadata, ;; (optional) Name of the Objective C property setter selector.
559 i32 ;; (optional) Objective C property attributes.
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]560}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]561</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]562</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]563
564<p>These descriptors are used to define types derived from other types. The
565value of the tag varies depending on the meaning. The following are possible
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]566tag values:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]567
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]568<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]569<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]570DW_TAG_formal_parameter = 5
571DW_TAG_member = 13
572DW_TAG_pointer_type = 15
573DW_TAG_reference_type = 16
574DW_TAG_typedef = 22
575DW_TAG_const_type = 38
576DW_TAG_volatile_type = 53
577DW_TAG_restrict_type = 55
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]578</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]579</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]580
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]581<p><tt>DW_TAG_member</tt> is used to define a member of
582 a <a href="#format_composite_type">composite type</a>
583 or <a href="#format_subprograms">subprogram</a>. The type of the member is
584 the <a href="#format_derived_type">derived
585 type</a>. <tt>DW_TAG_formal_parameter</tt> is used to define a member which
586 is a formal argument of a subprogram.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]587
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]588<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]589
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]590<p><tt>DW_TAG_pointer_type</tt>,<tt>DW_TAG_reference_type</tt>,
591 <tt>DW_TAG_const_type</tt>, <tt>DW_TAG_volatile_type</tt>
592 and <tt>DW_TAG_restrict_type</tt> are used to qualify
593 the <a href="#format_derived_type">derived type</a>. </p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]594
595<p><a href="#format_derived_type">Derived type</a> location can be determined
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]596 from the compile unit and line number. The size, alignment and offset are
597 expressed in bits and can be 64 bit values. The alignment is used to round
598 the offset when embedded in a <a href="#format_composite_type">composite
599 type</a> (example to keep float doubles on 64 bit boundaries.) The offset is
600 the bit offset if embedded in a <a href="#format_composite_type">composite
601 type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]602
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]603<p>Note that the <tt>void *</tt> type is expressed as a type derived from NULL.
604</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]605
606</div>
607
608<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]609<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]610 <a name="format_composite_type">Composite type descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]611</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]612
613<div class="doc_text">
614
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]615<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]616<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]617!6 = metadata !{
618 i32, ;; Tag (see below)
619 metadata, ;; Reference to context
620 metadata, ;; Name (may be "" for anonymous types)
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]621 metadata, ;; Reference to file where defined (may be NULL)
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]622 i32, ;; Line number where defined (may be 0)
623 i64, ;; Size in bits
624 i64, ;; Alignment in bits
625 i64, ;; Offset in bits
626 i32, ;; Flags
627 metadata, ;; Reference to type derived from
628 metadata, ;; Reference to array of member descriptors
629 i32 ;; Runtime languages
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]630}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]631</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]632</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]633
634<p>These descriptors are used to define types that are composed of 0 or more
635elements. The value of the tag varies depending on the meaning. The following
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]636are possible tag values:</p>
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>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]640DW_TAG_array_type = 1
641DW_TAG_enumeration_type = 4
642DW_TAG_structure_type = 19
643DW_TAG_union_type = 23
644DW_TAG_vector_type = 259
Bruno Cardoso Lopesd80ddc02009-05-29 17:08:57 +0000[diff] [blame]645DW_TAG_subroutine_type = 21
646DW_TAG_inheritance = 28
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]647</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]648</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]649
Jim Laskeyf8a01a92006-06-15 20:51:43 +0000[diff] [blame]650<p>The vector flag indicates that an array type is a native packed vector.</p>
651
Jim Laskey7089f452006-06-16 13:14:03 +0000[diff] [blame]652<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]653 (tag = <tt>DW_TAG_vector_type</tt>) are <a href="#format_subrange">subrange
654 descriptors</a>, each representing the range of subscripts at that level of
655 indexing.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]656
657<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]658 <a href="#format_enumeration">enumerator descriptors</a>, each representing
Devang Patelda6eed32011-03-29 17:27:08 +0000[diff] [blame]659 the definition of enumeration value for the set. All enumeration type
660 descriptors are collected by named metadata <tt>!llvm.dbg.enum</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]661
662<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]663 = <tt>DW_TAG_union_type</tt>) types are any one of
664 the <a href="#format_basic_type">basic</a>,
665 <a href="#format_derived_type">derived</a>
666 or <a href="#format_composite_type">composite</a> type descriptors, each
667 representing a field member of the structure or union.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]668
Jim Laskey4a9df242006-08-21 21:21:06 +0000[diff] [blame]669<p>For C++ classes (tag = <tt>DW_TAG_structure_type</tt>), member descriptors
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]670 provide information about base classes, static members and member
671 functions. If a member is a <a href="#format_derived_type">derived type
672 descriptor</a> and has a tag of <tt>DW_TAG_inheritance</tt>, then the type
673 represents a base class. If the member of is
674 a <a href="#format_global_variables">global variable descriptor</a> then it
675 represents a static member. And, if the member is
676 a <a href="#format_subprograms">subprogram descriptor</a> then it represents
677 a member function. For static members and member
678 functions, <tt>getName()</tt> returns the members link or the C++ mangled
679 name. <tt>getDisplayName()</tt> the simplied version of the name.</p>
Jim Laskey4a9df242006-08-21 21:21:06 +0000[diff] [blame]680
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]681<p>The first member of subroutine (tag = <tt>DW_TAG_subroutine_type</tt>) type
682 elements is the return type for the subroutine. The remaining elements are
683 the formal arguments to the subroutine.</p>
Jim Laskey094ee722006-06-20 21:13:20 +0000[diff] [blame]684
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]685<p><a href="#format_composite_type">Composite type</a> location can be
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]686 determined from the compile unit and line number. The size, alignment and
687 offset are expressed in bits and can be 64 bit values. The alignment is used
688 to round the offset when embedded in
689 a <a href="#format_composite_type">composite type</a> (as an example, to keep
690 float doubles on 64 bit boundaries.) The offset is the bit offset if embedded
691 in a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]692
693</div>
694
695<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]696<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]697 <a name="format_subrange">Subrange descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]698</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]699
700<div class="doc_text">
701
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]702<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]703<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]704!42 = metadata !{
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]705 i32, ;; Tag = 33 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subrange_type)
706 i64, ;; Low value
707 i64 ;; High value
708}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]709</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]710</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]711
712<p>These descriptors are used to define ranges of array subscripts for an array
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]713 <a href="#format_composite_type">composite type</a>. The low value defines
714 the lower bounds typically zero for C/C++. The high value is the upper
715 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]716 > high the array bounds are not included in generated debugging information.
717</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]718
719</div>
720
721<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]722<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]723 <a name="format_enumeration">Enumerator descriptors</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]724</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]725
726<div class="doc_text">
727
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]728<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]729<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]730!6 = metadata !{
731 i32, ;; Tag = 40 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
732 ;; (DW_TAG_enumerator)
733 metadata, ;; Name
734 i64 ;; Value
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]735}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]736</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]737</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]738
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]739<p>These descriptors are used to define members of an
740 enumeration <a href="#format_composite_type">composite type</a>, it
741 associates the name to the value.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]742
743</div>
744
745<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]746<h4>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]747 <a name="format_variables">Local variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]748</h4>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]749
750<div class="doc_text">
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]751
752<div class="doc_code">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]753<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]754!7 = metadata !{
755 i32, ;; Tag (see below)
756 metadata, ;; Context
757 metadata, ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]758 metadata, ;; Reference to file where defined
Devang Patela83688f2011-03-08 16:29:40 +0000[diff] [blame]759 i32, ;; 24 bit - Line number where defined
760 ;; 8 bit - Argument number. 1 indicates 1st argument.
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]761 metadata ;; Type descriptor
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]762}
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]763</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]764</div>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]765
766<p>These descriptors are used to define variables local to a sub program. The
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]767 value of the tag depends on the usage of the variable:</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]768
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]769<div class="doc_code">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]770<pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]771DW_TAG_auto_variable = 256
772DW_TAG_arg_variable = 257
773DW_TAG_return_variable = 258
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]774</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]775</div>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]776
777<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]778 argument variable is any variable that appears as a formal argument to the
779 function. A return variable is used to track the result of a function and
780 has no source correspondent.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]781
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame]782<p>The context is either the subprogram or block where the variable is defined.
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]783 Name the source variable name. Compile unit and line indicate where the
784 variable was defined. Type descriptor defines the declared type of the
785 variable.</p>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]786
787</div>
788
789<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]790<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]791 <a name="format_common_intrinsics">Debugger intrinsic functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]792</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]793
794<div class="doc_text">
795
796<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]797 provide debug information at various points in generated code.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]798
799</div>
800
801<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]802<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]803 <a name="format_common_declare">llvm.dbg.declare</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]804</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]805
806<div class="doc_text">
807<pre>
Devang Patel4c7c0c62010-10-01 19:22:16 +0000[diff] [blame]808 void %<a href="#format_common_declare">llvm.dbg.declare</a>(metadata, metadata)
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]809</pre>
810
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame]811<p>This intrinsic provides information about a local element (ex. variable.) The
NAKAMURA Takumi4d6deb02011-04-09 09:51:57 +0000[diff] [blame]812 first argument is metadata holding alloca for the variable. The
Devang Patele136e502011-02-01 17:22:12 +0000[diff] [blame]813 second argument is metadata containing description of the variable. </p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]814</div>
815
816<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]817<h4>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]818 <a name="format_common_value">llvm.dbg.value</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]819</h4>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]820
821<div class="doc_text">
822<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]823 void %<a href="#format_common_value">llvm.dbg.value</a>(metadata, i64, metadata)
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]824</pre>
825
826<p>This intrinsic provides information when a user source variable is set to a
827 new value. The first argument is the new value (wrapped as metadata). The
828 second argument is the offset in the user source variable where the new value
Devang Patele136e502011-02-01 17:22:12 +0000[diff] [blame]829 is written. The third argument is metadata containing description of the
830 user source variable. </p>
Victor Hernandez67a1a542010-01-11 22:53:48 +0000[diff] [blame]831</div>
832
833<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]834<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]835 <a name="format_common_lifetime">Object lifetimes and scoping</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]836</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]837
838<div class="doc_text">
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]839<p>In many languages, the local variables in functions can have their lifetimes
840 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]841 for example, variables are only live (readable and writable) within the
842 source block that they are defined in. In functional languages, values are
843 only readable after they have been defined. Though this is a very obvious
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]844 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]845 scoping in this sense, and does not want to be tied to a language's scoping
846 rules.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]847
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]848<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]849 llvm instructions to encode line number and scoping information. Consider
850 the following C fragment, for example:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]851
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]852<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]853<pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8541. void foo() {
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8552. int X = 21;
8563. int Y = 22;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8574. {
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8585. int Z = 23;
8596. Z = X;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8607. }
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]8618. X = Y;
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8629. }
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]863</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]864</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]865
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]866<p>Compiled to LLVM, this function would be represented like this:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]867
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]868<div class="doc_code">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]869<pre>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]870define void @foo() nounwind ssp {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]871entry:
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]872 %X = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
873 %Y = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
874 %Z = alloca i32, align 4 ; &lt;i32*&gt; [#uses=3]
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]875 %0 = bitcast i32* %X to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]876 call void @llvm.dbg.declare(metadata !{i32 * %X}, metadata !0), !dbg !7
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]877 store i32 21, i32* %X, !dbg !8
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]878 %1 = bitcast i32* %Y to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]879 call void @llvm.dbg.declare(metadata !{i32 * %Y}, metadata !9), !dbg !10
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]880 store i32 22, i32* %Y, !dbg !11
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]881 %2 = bitcast i32* %Z to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]882 call void @llvm.dbg.declare(metadata !{i32 * %Z}, metadata !12), !dbg !14
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]883 store i32 23, i32* %Z, !dbg !15
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]884 %tmp = load i32* %X, !dbg !16 ; &lt;i32&gt; [#uses=1]
885 %tmp1 = load i32* %Y, !dbg !16 ; &lt;i32&gt; [#uses=1]
886 %add = add nsw i32 %tmp, %tmp1, !dbg !16 ; &lt;i32&gt; [#uses=1]
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]887 store i32 %add, i32* %Z, !dbg !16
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]888 %tmp2 = load i32* %Y, !dbg !17 ; &lt;i32&gt; [#uses=1]
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]889 store i32 %tmp2, i32* %X, !dbg !17
890 ret void, !dbg !18
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]891}
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]892
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]893declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]894
895!0 = metadata !{i32 459008, metadata !1, metadata !"X",
896 metadata !3, i32 2, metadata !6}; [ DW_TAG_auto_variable ]
897!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
898!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo", metadata !"foo",
899 metadata !"foo", metadata !3, i32 1, metadata !4,
900 i1 false, i1 true}; [DW_TAG_subprogram ]
901!3 = metadata !{i32 458769, i32 0, i32 12, metadata !"foo.c",
902 metadata !"/private/tmp", metadata !"clang 1.1", i1 true,
903 i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
904!4 = metadata !{i32 458773, metadata !3, metadata !"", null, i32 0, i64 0, i64 0,
905 i64 0, i32 0, null, metadata !5, i32 0}; [DW_TAG_subroutine_type ]
906!5 = metadata !{null}
907!6 = metadata !{i32 458788, metadata !3, metadata !"int", metadata !3, i32 0,
908 i64 32, i64 32, i64 0, i32 0, i32 5}; [DW_TAG_base_type ]
909!7 = metadata !{i32 2, i32 7, metadata !1, null}
910!8 = metadata !{i32 2, i32 3, metadata !1, null}
911!9 = metadata !{i32 459008, metadata !1, metadata !"Y", metadata !3, i32 3,
912 metadata !6}; [ DW_TAG_auto_variable ]
913!10 = metadata !{i32 3, i32 7, metadata !1, null}
914!11 = metadata !{i32 3, i32 3, metadata !1, null}
915!12 = metadata !{i32 459008, metadata !13, metadata !"Z", metadata !3, i32 5,
916 metadata !6}; [ DW_TAG_auto_variable ]
917!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
918!14 = metadata !{i32 5, i32 9, metadata !13, null}
919!15 = metadata !{i32 5, i32 5, metadata !13, null}
920!16 = metadata !{i32 6, i32 5, metadata !13, null}
921!17 = metadata !{i32 8, i32 3, metadata !1, null}
922!18 = metadata !{i32 9, i32 1, metadata !2, null}
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]923</pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]924</div>
925
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]926<p>This example illustrates a few important details about LLVM debugging
927 information. In particular, it shows how the <tt>llvm.dbg.declare</tt>
928 intrinsic and location information, which are attached to an instruction,
929 are applied together to allow a debugger to analyze the relationship between
930 statements, variable definitions, and the code used to implement the
931 function.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]932
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]933<div class="doc_code">
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]934<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]935call void @llvm.dbg.declare(metadata, metadata !0), !dbg !7
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]936</pre>
937</div>
938
939<p>The first intrinsic
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]940 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]941 encodes debugging information for the variable <tt>X</tt>. The metadata
942 <tt>!dbg !7</tt> attached to the intrinsic provides scope information for the
943 variable <tt>X</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]944
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]945<div class="doc_code">
946<pre>
947!7 = metadata !{i32 2, i32 7, metadata !1, null}
948!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
949!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo",
950 metadata !"foo", metadata !"foo", metadata !3, i32 1,
951 metadata !4, i1 false, i1 true}; [DW_TAG_subprogram ]
952</pre>
953</div>
954
955<p>Here <tt>!7</tt> is metadata providing location information. It has four
956 fields: line number, column number, scope, and original scope. The original
957 scope represents inline location if this instruction is inlined inside a
958 caller, and is null otherwise. In this example, scope is encoded by
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]959 <tt>!1</tt>. <tt>!1</tt> represents a lexical block inside the scope
960 <tt>!2</tt>, where <tt>!2</tt> is a
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]961 <a href="#format_subprograms">subprogram descriptor</a>. This way the
962 location information attached to the intrinsics indicates that the
963 variable <tt>X</tt> is declared at line number 2 at a function level scope in
964 function <tt>foo</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]965
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]966<p>Now lets take another example.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]967
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]968<div class="doc_code">
Bill Wendling02216ff2009-12-01 00:59:58 +0000[diff] [blame]969<pre>
Devang Patel37280782011-02-03 00:22:17 +0000[diff] [blame]970call void @llvm.dbg.declare(metadata, metadata !12), !dbg !14
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]971</pre>
972</div>
973
974<p>The second intrinsic
Devang Patel744950d2009-11-25 23:28:01 +0000[diff] [blame]975 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]976 encodes debugging information for variable <tt>Z</tt>. The metadata
977 <tt>!dbg !14</tt> attached to the intrinsic provides scope information for
978 the variable <tt>Z</tt>.</p>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]979
Bill Wendlingcf493b82009-12-01 00:53:11 +0000[diff] [blame]980<div class="doc_code">
981<pre>
982!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
983!14 = metadata !{i32 5, i32 9, metadata !13, null}
984</pre>
985</div>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]986
John Criswellb34500f2010-03-17 15:01:50 +0000[diff] [blame]987<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]988 column number 9 inside of lexical scope <tt>!13</tt>. The lexical scope
989 itself resides inside of lexical scope <tt>!1</tt> described above.</p>
990
991<p>The scope information attached with each instruction provides a
992 straightforward way to find instructions covered by a scope.</p>
993
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]994</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]995
996<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]997<h2>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]998 <a name="ccxx_frontend">C/C++ front-end specific debug information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]999</h2>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]1000<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1001
1002<div class="doc_text">
1003
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1004<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]1005 that is effectively identical
1006 to <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3.0</a> in
1007 terms of information content. This allows code generators to trivially
1008 support native debuggers by generating standard dwarf information, and
1009 contains enough information for non-dwarf targets to translate it as
1010 needed.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1011
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1012<p>This section describes the forms used to represent C and C++ programs. Other
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1013 languages could pattern themselves after this (which itself is tuned to
1014 representing programs in the same way that DWARF 3 does), or they could
1015 choose to provide completely different forms if they don't fit into the DWARF
1016 model. As support for debugging information gets added to the various LLVM
1017 source-language front-ends, the information used should be documented
1018 here.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1019
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1020<p>The following sections provide examples of various C/C++ constructs and the
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1021 debug information that would best describe those constructs.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1022
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1023</div>
1024
1025<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1026<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1027 <a name="ccxx_compile_units">C/C++ source file information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1028</h3>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1029
1030<div class="doc_text">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1031
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1032<p>Given the source files <tt>MySource.cpp</tt> and <tt>MyHeader.h</tt> located
1033 in the directory <tt>/Users/mine/sources</tt>, the following code:</p>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1034
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1035<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1036<pre>
1037#include "MyHeader.h"
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1038
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1039int main(int argc, char *argv[]) {
1040 return 0;
1041}
1042</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1043</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1044
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1045<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1046
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1047<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1048<pre>
1049...
1050;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1051;; Define the compile unit for the main source file "/Users/mine/sources/MySource.cpp".
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1052;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1053!2 = metadata !{
1054 i32 524305, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1055 i32 0, ;; Unused
1056 i32 4, ;; Language Id
1057 metadata !"MySource.cpp",
1058 metadata !"/Users/mine/sources",
1059 metadata !"4.2.1 (Based on Apple Inc. build 5649) (LLVM build 00)",
1060 i1 true, ;; Main Compile Unit
1061 i1 false, ;; Optimized compile unit
1062 metadata !"", ;; Compiler flags
1063 i32 0} ;; Runtime version
1064
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1065;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1066;; Define the file for the file "/Users/mine/sources/MySource.cpp".
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1067;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1068!1 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1069 i32 524329, ;; Tag
1070 metadata !"MySource.cpp",
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1071 metadata !"/Users/mine/sources",
Devang Patel9fea9c22010-07-13 16:53:20 +0000[diff] [blame]1072 metadata !2 ;; Compile unit
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1073}
1074
1075;;
1076;; Define the file for the file "/Users/mine/sources/Myheader.h"
1077;;
1078!3 = metadata !{
1079 i32 524329, ;; Tag
1080 metadata !"Myheader.h"
1081 metadata !"/Users/mine/sources",
Devang Patel9fea9c22010-07-13 16:53:20 +0000[diff] [blame]1082 metadata !2 ;; Compile unit
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1083}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1084
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1085...
1086</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1087</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1088
Devang Pateld98ec5f2010-03-26 19:08:36 +0000[diff] [blame]1089<p>llvm::Instruction provides easy access to metadata attached with an
1090instruction. One can extract line number information encoded in LLVM IR
1091using <tt>Instruction::getMetadata()</tt> and
1092<tt>DILocation::getLineNumber()</tt>.
1093<pre>
1094 if (MDNode *N = I->getMetadata("dbg")) { // Here I is an LLVM instruction
1095 DILocation Loc(N); // DILocation is in DebugInfo.h
1096 unsigned Line = Loc.getLineNumber();
1097 StringRef File = Loc.getFilename();
1098 StringRef Dir = Loc.getDirectory();
1099 }
1100</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1101</div>
1102
1103<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1104<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1105 <a name="ccxx_global_variable">C/C++ global variable information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1106</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1107
1108<div class="doc_text">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1109
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1110<p>Given an integer global variable declared as follows:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1111
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1112<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1113<pre>
1114int MyGlobal = 100;
1115</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1116</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1117
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1118<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1119
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1120<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1121<pre>
1122;;
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1123;; Define the global itself.
1124;;
1125%MyGlobal = global int 100
1126...
1127;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1128;; List of debug info of globals
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1129;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1130!llvm.dbg.gv = !{!0}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1131
1132;;
1133;; Define the global variable descriptor. Note the reference to the global
1134;; variable anchor and the global variable itself.
1135;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1136!0 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1137 i32 524340, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1138 i32 0, ;; Unused
1139 metadata !1, ;; Context
1140 metadata !"MyGlobal", ;; Name
1141 metadata !"MyGlobal", ;; Display Name
1142 metadata !"MyGlobal", ;; Linkage Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1143 metadata !3, ;; Compile Unit
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1144 i32 1, ;; Line Number
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1145 metadata !4, ;; Type
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1146 i1 false, ;; Is a local variable
1147 i1 true, ;; Is this a definition
1148 i32* @MyGlobal ;; The global variable
1149}
1150
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1151;;
1152;; Define the basic type of 32 bit signed integer. Note that since int is an
1153;; intrinsic type the source file is NULL and line 0.
1154;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1155!4 = metadata !{
1156 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1157 metadata !1, ;; Context
1158 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1159 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1160 i32 0, ;; Line number
1161 i64 32, ;; Size in Bits
1162 i64 32, ;; Align in Bits
1163 i64 0, ;; Offset in Bits
1164 i32 0, ;; Flags
1165 i32 5 ;; Encoding
1166}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1167
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1168</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1169</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1170
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1171</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1172
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1173<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1174<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1175 <a name="ccxx_subprogram">C/C++ function information</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1176</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1177
1178<div class="doc_text">
1179
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1180<p>Given a function declared as follows:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1181
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1182<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1183<pre>
1184int main(int argc, char *argv[]) {
1185 return 0;
1186}
1187</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1188</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1189
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1190<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1191
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1192<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1193<pre>
1194;;
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1195;; Define the anchor for subprograms. Note that the second field of the
1196;; anchor is 46, which is the same as the tag for subprograms
1197;; (46 = DW_TAG_subprogram.)
1198;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1199!6 = metadata !{
1200 i32 524334, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1201 i32 0, ;; Unused
1202 metadata !1, ;; Context
1203 metadata !"main", ;; Name
1204 metadata !"main", ;; Display name
1205 metadata !"main", ;; Linkage name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1206 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1207 i32 1, ;; Line number
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1208 metadata !4, ;; Type
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1209 i1 false, ;; Is local
Devang Patelda194752011-04-05 22:52:06 +0000[diff] [blame]1210 i1 true, ;; Is definition
1211 i32 0, ;; Virtuality attribute, e.g. pure virtual function
1212 i32 0, ;; Index into virtual table for C++ methods
1213 i32 0, ;; Type that holds virtual table.
1214 i32 0, ;; Flags
1215 i1 false, ;; True if this function is optimized
1216 Function *, ;; Pointer to llvm::Function
1217 null ;; Function template parameters
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1218}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1219;;
1220;; Define the subprogram itself.
1221;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1222define i32 @main(i32 %argc, i8** %argv) {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1223...
1224}
1225</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1226</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1227
1228</div>
1229
1230<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1231<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1232 <a name="ccxx_basic_types">C/C++ basic types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1233</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1234
1235<div class="doc_text">
1236
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1237<p>The following are the basic type descriptors for C/C++ core types:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1238
1239</div>
1240
1241<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1242<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1243 <a name="ccxx_basic_type_bool">bool</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1244</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1245
1246<div class="doc_text">
1247
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1248<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1249<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1250!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1251 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1252 metadata !1, ;; Context
1253 metadata !"bool", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1254 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1255 i32 0, ;; Line number
1256 i64 8, ;; Size in Bits
1257 i64 8, ;; Align in Bits
1258 i64 0, ;; Offset in Bits
1259 i32 0, ;; Flags
1260 i32 2 ;; Encoding
1261}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1262</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1263</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1264
1265</div>
1266
1267<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1268<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1269 <a name="ccxx_basic_char">char</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1270</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1271
1272<div class="doc_text">
1273
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1274<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1275<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1276!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1277 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1278 metadata !1, ;; Context
1279 metadata !"char", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1280 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1281 i32 0, ;; Line number
1282 i64 8, ;; Size in Bits
1283 i64 8, ;; Align in Bits
1284 i64 0, ;; Offset in Bits
1285 i32 0, ;; Flags
1286 i32 6 ;; Encoding
1287}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1288</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1289</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1290
1291</div>
1292
1293<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1294<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1295 <a name="ccxx_basic_unsigned_char">unsigned char</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1296</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1297
1298<div class="doc_text">
1299
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1300<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1301<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1302!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1303 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1304 metadata !1, ;; Context
1305 metadata !"unsigned char",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1306 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1307 i32 0, ;; Line number
1308 i64 8, ;; Size in Bits
1309 i64 8, ;; Align in Bits
1310 i64 0, ;; Offset in Bits
1311 i32 0, ;; Flags
1312 i32 8 ;; Encoding
1313}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1314</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1315</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1316
1317</div>
1318
1319<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1320<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1321 <a name="ccxx_basic_short">short</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1322</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1323
1324<div class="doc_text">
1325
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1326<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1327<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1328!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1329 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1330 metadata !1, ;; Context
1331 metadata !"short int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1332 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1333 i32 0, ;; Line number
1334 i64 16, ;; Size in Bits
1335 i64 16, ;; Align in Bits
1336 i64 0, ;; Offset in Bits
1337 i32 0, ;; Flags
1338 i32 5 ;; Encoding
1339}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1340</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1341</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1342
1343</div>
1344
1345<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1346<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1347 <a name="ccxx_basic_unsigned_short">unsigned short</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1348</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1349
1350<div class="doc_text">
1351
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1352<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1353<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1354!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1355 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1356 metadata !1, ;; Context
1357 metadata !"short unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1358 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1359 i32 0, ;; Line number
1360 i64 16, ;; Size in Bits
1361 i64 16, ;; Align in Bits
1362 i64 0, ;; Offset in Bits
1363 i32 0, ;; Flags
1364 i32 7 ;; Encoding
1365}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1366</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1367</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1368
1369</div>
1370
1371<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1372<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1373 <a name="ccxx_basic_int">int</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1374</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1375
1376<div class="doc_text">
1377
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1378<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1379<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1380!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1381 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1382 metadata !1, ;; Context
1383 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1384 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1385 i32 0, ;; Line number
1386 i64 32, ;; Size in Bits
1387 i64 32, ;; Align in Bits
1388 i64 0, ;; Offset in Bits
1389 i32 0, ;; Flags
1390 i32 5 ;; Encoding
1391}
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1392</pre></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_unsigned_int">unsigned 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
1401<div class="doc_text">
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 !"unsigned int",
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 7 ;; Encoding
1416}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1417</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1418</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1419
1420</div>
1421
1422<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1423<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1424 <a name="ccxx_basic_long_long">long long</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1425</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1426
1427<div class="doc_text">
1428
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1429<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1430<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1431!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1432 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1433 metadata !1, ;; Context
1434 metadata !"long long int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1435 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1436 i32 0, ;; Line number
1437 i64 64, ;; Size in Bits
1438 i64 64, ;; Align in Bits
1439 i64 0, ;; Offset in Bits
1440 i32 0, ;; Flags
1441 i32 5 ;; Encoding
1442}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1443</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1444</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1445
1446</div>
1447
1448<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1449<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1450 <a name="ccxx_basic_unsigned_long_long">unsigned long long</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1451</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1452
1453<div class="doc_text">
1454
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1455<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1456<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1457!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1458 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1459 metadata !1, ;; Context
1460 metadata !"long long unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1461 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1462 i32 0, ;; Line number
1463 i64 64, ;; Size in Bits
1464 i64 64, ;; Align in Bits
1465 i64 0, ;; Offset in Bits
1466 i32 0, ;; Flags
1467 i32 7 ;; Encoding
1468}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1469</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1470</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1471
1472</div>
1473
1474<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1475<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1476 <a name="ccxx_basic_float">float</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1477</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1478
1479<div class="doc_text">
1480
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1481<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1482<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1483!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1484 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1485 metadata !1, ;; Context
1486 metadata !"float",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1487 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1488 i32 0, ;; Line number
1489 i64 32, ;; Size in Bits
1490 i64 32, ;; Align in Bits
1491 i64 0, ;; Offset in Bits
1492 i32 0, ;; Flags
1493 i32 4 ;; Encoding
1494}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1495</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1496</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1497
1498</div>
1499
1500<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1501<h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1502 <a name="ccxx_basic_double">double</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1503</h4>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1504
1505<div class="doc_text">
1506
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1507<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1508<pre>
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1509!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1510 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1511 metadata !1, ;; Context
1512 metadata !"double",;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1513 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1514 i32 0, ;; Line number
1515 i64 64, ;; Size in Bits
1516 i64 64, ;; Align in Bits
1517 i64 0, ;; Offset in Bits
1518 i32 0, ;; Flags
1519 i32 4 ;; Encoding
1520}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1521</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1522</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1523
1524</div>
1525
1526<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1527<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1528 <a name="ccxx_derived_types">C/C++ derived types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1529</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1530
1531<div class="doc_text">
1532
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1533<p>Given the following as an example of C/C++ derived type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1534
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1535<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1536<pre>
1537typedef const int *IntPtr;
1538</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1539</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1540
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1541<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1542
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1543<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1544<pre>
1545;;
1546;; Define the typedef "IntPtr".
1547;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1548!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1549 i32 524310, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1550 metadata !1, ;; Context
1551 metadata !"IntPtr", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1552 metadata !3, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1553 i32 0, ;; Line number
1554 i64 0, ;; Size in bits
1555 i64 0, ;; Align in bits
1556 i64 0, ;; Offset in bits
1557 i32 0, ;; Flags
1558 metadata !4 ;; Derived From type
1559}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1560
1561;;
1562;; Define the pointer type.
1563;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1564!4 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1565 i32 524303, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1566 metadata !1, ;; Context
1567 metadata !"", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1568 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1569 i32 0, ;; Line number
1570 i64 64, ;; Size in bits
1571 i64 64, ;; Align in bits
1572 i64 0, ;; Offset in bits
1573 i32 0, ;; Flags
1574 metadata !5 ;; Derived From type
1575}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1576;;
1577;; Define the const type.
1578;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1579!5 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1580 i32 524326, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1581 metadata !1, ;; Context
1582 metadata !"", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1583 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1584 i32 0, ;; Line number
1585 i64 32, ;; Size in bits
1586 i64 32, ;; Align in bits
1587 i64 0, ;; Offset in bits
1588 i32 0, ;; Flags
1589 metadata !6 ;; Derived From type
1590}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1591;;
1592;; Define the int type.
1593;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1594!6 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1595 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1596 metadata !1, ;; Context
1597 metadata !"int", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1598 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1599 i32 0, ;; Line number
1600 i64 32, ;; Size in bits
1601 i64 32, ;; Align in bits
1602 i64 0, ;; Offset in bits
1603 i32 0, ;; Flags
1604 5 ;; Encoding
1605}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1606</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1607</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1608
1609</div>
1610
1611<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1612<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1613 <a name="ccxx_composite_types">C/C++ struct/union types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1614</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1615
1616<div class="doc_text">
1617
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1618<p>Given the following as an example of C/C++ struct type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1619
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1620<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1621<pre>
1622struct Color {
1623 unsigned Red;
1624 unsigned Green;
1625 unsigned Blue;
1626};
1627</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1628</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1629
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1630<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1631
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1632<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1633<pre>
1634;;
1635;; Define basic type for unsigned int.
1636;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1637!5 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1638 i32 524324, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1639 metadata !1, ;; Context
1640 metadata !"unsigned int",
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1641 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1642 i32 0, ;; Line number
1643 i64 32, ;; Size in Bits
1644 i64 32, ;; Align in Bits
1645 i64 0, ;; Offset in Bits
1646 i32 0, ;; Flags
1647 i32 7 ;; Encoding
1648}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1649;;
1650;; Define composite type for struct Color.
1651;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1652!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1653 i32 524307, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1654 metadata !1, ;; Context
1655 metadata !"Color", ;; Name
1656 metadata !1, ;; Compile unit
1657 i32 1, ;; Line number
1658 i64 96, ;; Size in bits
1659 i64 32, ;; Align in bits
1660 i64 0, ;; Offset in bits
1661 i32 0, ;; Flags
1662 null, ;; Derived From
1663 metadata !3, ;; Elements
1664 i32 0 ;; Runtime Language
1665}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1666
1667;;
1668;; Define the Red field.
1669;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1670!4 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1671 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1672 metadata !1, ;; Context
1673 metadata !"Red", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1674 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1675 i32 2, ;; Line number
1676 i64 32, ;; Size in bits
1677 i64 32, ;; Align in bits
1678 i64 0, ;; Offset in bits
1679 i32 0, ;; Flags
1680 metadata !5 ;; Derived From type
1681}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1682
1683;;
1684;; Define the Green field.
1685;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1686!6 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1687 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1688 metadata !1, ;; Context
1689 metadata !"Green", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1690 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1691 i32 3, ;; Line number
1692 i64 32, ;; Size in bits
1693 i64 32, ;; Align in bits
1694 i64 32, ;; Offset in bits
1695 i32 0, ;; Flags
1696 metadata !5 ;; Derived From type
1697}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1698
1699;;
1700;; Define the Blue field.
1701;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1702!7 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1703 i32 524301, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1704 metadata !1, ;; Context
1705 metadata !"Blue", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1706 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1707 i32 4, ;; Line number
1708 i64 32, ;; Size in bits
1709 i64 32, ;; Align in bits
1710 i64 64, ;; Offset in bits
1711 i32 0, ;; Flags
1712 metadata !5 ;; Derived From type
1713}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1714
1715;;
1716;; Define the array of fields used by the composite type Color.
1717;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1718!3 = metadata !{metadata !4, metadata !6, metadata !7}
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1719</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1720</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1721
1722</div>
1723
1724<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1725<h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1726 <a name="ccxx_enumeration_types">C/C++ enumeration types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame^]1727</h3>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1728
1729<div class="doc_text">
1730
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1731<p>Given the following as an example of C/C++ enumeration type:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1732
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1733<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1734<pre>
1735enum Trees {
1736 Spruce = 100,
1737 Oak = 200,
1738 Maple = 300
1739};
1740</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1741</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1742
Misha Brukman96e00812008-12-16 02:54:22 +0000[diff] [blame]1743<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1744
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1745<div class="doc_code">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1746<pre>
1747;;
1748;; Define composite type for enum Trees
1749;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1750!2 = metadata !{
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1751 i32 524292, ;; Tag
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1752 metadata !1, ;; Context
1753 metadata !"Trees", ;; Name
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1754 metadata !1, ;; File
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1755 i32 1, ;; Line number
1756 i64 32, ;; Size in bits
1757 i64 32, ;; Align in bits
1758 i64 0, ;; Offset in bits
1759 i32 0, ;; Flags
1760 null, ;; Derived From type
1761 metadata !3, ;; Elements
1762 i32 0 ;; Runtime language
1763}
Devang Patel2a610c72009-08-25 05:24:07 +0000[diff] [blame]1764
Devang Patel82459882009-08-26 05:01:18 +0000[diff] [blame]1765;;
1766;; Define the array of enumerators used by composite type Trees.
1767;;
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1768!3 = metadata !{metadata !4, metadata !5, metadata !6}
1769
1770;;
1771;; Define Spruce enumerator.
1772;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1773!4 = metadata !{i32 524328, metadata !"Spruce", i64 100}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1774
1775;;
1776;; Define Oak enumerator.
1777;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1778!5 = metadata !{i32 524328, metadata !"Oak", i64 200}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1779
1780;;
1781;; Define Maple enumerator.
1782;;
Devang Patel4b945502010-03-09 00:44:10 +0000[diff] [blame]1783!6 = metadata !{i32 524328, metadata !"Maple", i64 300}
Devang Patele4b27562009-08-28 23:24:31 +0000[diff] [blame]1784
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1785</pre>
Bill Wendling48839d92009-05-17 05:52:39 +0000[diff] [blame]1786</div>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1787
1788</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1789
1790<!-- *********************************************************************** -->
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1791
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1792<hr>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1793<address>
1794 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1795 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1796 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1797 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1798
1799 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]1800 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1801 Last modified: $Date$
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1802</address>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1803
1804</body>
1805</html>