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Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]6 <title>Source Level Debugging with LLVM</title>
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10
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]11<h1>Source Level Debugging with LLVM</h1>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]12
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]13<table class="layout" style="width:100%">
14 <tr class="layout">
15 <td class="left">
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]16<ul>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]17 <li><a href="#introduction">Introduction</a>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]18 <ol>
19 <li><a href="#phil">Philosophy behind LLVM debugging information</a></li>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]20 <li><a href="#consumers">Debug information consumers</a></li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]21 <li><a href="#debugopt">Debugging optimized code</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]22 </ol></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]23 <li><a href="#format">Debugging information format</a>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]24 <ol>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]25 <li><a href="#debug_info_descriptors">Debug information descriptors</a>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]26 <ul>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]27 <li><a href="#format_compile_units">Compile unit descriptors</a></li>
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]28 <li><a href="#format_files">File descriptors</a></li>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]29 <li><a href="#format_global_variables">Global variable descriptors</a></li>
30 <li><a href="#format_subprograms">Subprogram descriptors</a></li>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]31 <li><a href="#format_blocks">Block descriptors</a></li>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]32 <li><a href="#format_basic_type">Basic type descriptors</a></li>
33 <li><a href="#format_derived_type">Derived type descriptors</a></li>
34 <li><a href="#format_composite_type">Composite type descriptors</a></li>
35 <li><a href="#format_subrange">Subrange descriptors</a></li>
36 <li><a href="#format_enumeration">Enumerator descriptors</a></li>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]37 <li><a href="#format_variables">Local variables</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]38 </ul></li>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]39 <li><a href="#format_common_intrinsics">Debugger intrinsic functions</a>
40 <ul>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]41 <li><a href="#format_common_declare">llvm.dbg.declare</a></li>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]42 <li><a href="#format_common_value">llvm.dbg.value</a></li>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]43 </ul></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]44 </ol></li>
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]45 <li><a href="#format_common_lifetime">Object lifetimes and scoping</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]46 <li><a href="#ccxx_frontend">C/C++ front-end specific debug information</a>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]47 <ol>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]48 <li><a href="#ccxx_compile_units">C/C++ source file information</a></li>
49 <li><a href="#ccxx_global_variable">C/C++ global variable information</a></li>
50 <li><a href="#ccxx_subprogram">C/C++ function information</a></li>
51 <li><a href="#ccxx_basic_types">C/C++ basic types</a></li>
52 <li><a href="#ccxx_derived_types">C/C++ derived types</a></li>
53 <li><a href="#ccxx_composite_types">C/C++ struct/union types</a></li>
54 <li><a href="#ccxx_enumeration_types">C/C++ enumeration types</a></li>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]55 </ol></li>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]56</ul>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]57</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]58<td class="right">
Misha Brukman3c1f8e72004-05-12 21:26:16 +0000[diff] [blame]59<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247"
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]60height="369">
61</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]62</tr></table>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]63
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]64<div class="doc_author">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]65 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
Jim Laskey6e8a2f42007-03-14 19:32:21 +0000[diff] [blame]66 and <a href="mailto:jlaskey@mac.com">Jim Laskey</a></p>
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]67</div>
68
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]69
70<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]71<h2><a name="introduction">Introduction</a></h2>
Misha Brukmancda6a9b2004-12-09 20:27:37 +0000[diff] [blame]72<!-- *********************************************************************** -->
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]73
74<div class="doc_text">
75
76<p>This document is the central repository for all information pertaining to
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]77 debug information in LLVM. It describes the <a href="#format">actual format
78 that the LLVM debug information</a> takes, which is useful for those
79 interested in creating front-ends or dealing directly with the information.
Chris Lattnercb3f64f2009-07-18 21:47:15 +0000[diff] [blame]80 Further, this document provides specific examples of what debug information
Chris Lattner92ec3d12011-01-18 06:12:10 +0000[diff] [blame]81 for C/C++ looks like.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]82
83</div>
84
85<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]86<h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]87 <a name="phil">Philosophy behind LLVM debugging information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]88</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]89
90<div class="doc_text">
91
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]92<p>The idea of the LLVM debugging information is to capture how the important
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]96
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]97<ul>
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]101
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]104
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]108
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]112
Bill Wendlinge9353d72009-05-17 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 Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]117</ul>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]118
Bill Wendlinge9353d72009-05-17 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 Patel80ae3492009-08-28 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 Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]127
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]128<p>When a program is being debugged, a debugger interacts with the user and
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]132
133</div>
134
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]135<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]136<h3>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]137 <a name="consumers">Debug information consumers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]138</h3>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]139
140<div class="doc_text">
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]141
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]142<p>The role of debug information is to provide meta information normally
Bill Wendlinge9353d72009-05-17 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 Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]146
Chris Lattner904f2172010-04-05 04:11:11 +0000[diff] [blame]147<p>Currently, debug information is consumed by DwarfDebug to produce dwarf
Bill Wendlinge9353d72009-05-17 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 Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]150
151<p>It would also be reasonable to use debug information to feed profiling tools
Bill Wendlinge9353d72009-05-17 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 Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]154
155<p>TODO - expound a bit more.</p>
156
157</div>
158
159<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]160<h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]161 <a name="debugopt">Debugging optimized code</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]162</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]163
164<div class="doc_text">
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]165
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]166<p>An extremely high priority of LLVM debugging information is to make it
Bill Wendlinge9353d72009-05-17 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 Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]169
170<ul>
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]178
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]184
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]190
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]195
Bill Wendlinge9353d72009-05-17 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 Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]200</ul>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]201
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]202<p>Basically, the debug information allows you to compile a program with
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]210
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]211<p><a href="TestingGuide.html#quicktestsuite">LLVM test suite</a> provides a
Bill Wendlinge9353d72009-05-17 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 Patelb885a912008-11-21 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 Wendlinge9353d72009-05-17 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 Patelb885a912008-11-21 19:35:57 +0000[diff] [blame]226
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]227</div>
228
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]229<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]230<h2>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]231 <a name="format">Debugging information format</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]232</h2>
Chris Lattner1811fca2004-01-05 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 Wendlinge9353d72009-05-17 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 Criswell2a4b0802010-03-17 15:01:50 +0000[diff] [blame]240 particular, the use of metadata avoids duplicated debugging information from
Devang Patel80ae3492009-08-28 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]244
245<p>To do this, most of the debugging information (descriptors for types,
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]246 variables, functions, source files, etc) is inserted by the language
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]247 front-end in the form of LLVM metadata. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]248
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]249<p>Debug information is designed to be agnostic about the target debugger and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]250 debugging information representation (e.g. DWARF/Stabs/etc). It uses a
Devang Patel80ae3492009-08-28 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]255
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]256<p>To provide basic functionality, the LLVM debugger does have to make some
Bill Wendlinge9353d72009-05-17 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 Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]259 exist are <a href="#format_files">source files</a>,
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]263
264<p>This section of the documentation first describes the representation aspects
Bill Wendlinge9353d72009-05-17 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]267
268</div>
269
270<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]271<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]272 <a name="debug_info_descriptors">Debug information descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]273</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]274
275<div class="doc_text">
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]276
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]277<p>In consideration of the complexity and volume of debug information, LLVM
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]278 provides a specification for well formed debug descriptors. </p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]279
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]280<p>Consumers of LLVM debug information expect the descriptors for program
Bill Wendlinge9353d72009-05-17 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 Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]288 the range 0x1000 through 0x2000 (there is a defined enum DW_TAG_user_base =
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]289 0x1000.)</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]290
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]291<p>The fields of debug descriptors used internally by LLVM
Nick Lewyckya87014f2010-03-31 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 Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]294
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]295<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]296<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]297!1 = metadata !{
Nick Lewyckya87014f2010-03-31 07:50:17 +0000[diff] [blame]298 i32, ;; A tag
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]299 ...
300}
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]301</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]302</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]303
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000[diff] [blame]304<p><a name="LLVMDebugVersion">The first field of a descriptor is always an
Nick Lewyckya87014f2010-03-31 07:50:17 +0000[diff] [blame]305 <tt>i32</tt> containing a tag value identifying the content of the
Bill Wendlinge9353d72009-05-17 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 Lewyckya87014f2010-03-31 07:50:17 +0000[diff] [blame]310 with the current debug version (LLVMDebugVersion = 8 &lt;&lt; 16 or 0x80000 or
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]311 524288.)</a></p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]312
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000[diff] [blame]313<p>The details of the various descriptors follow.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]314
315</div>
316
317<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]318<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]319 <a name="format_compile_units">Compile unit descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]320</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]321
322<div class="doc_text">
323
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]324<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]325<pre>
Devang Patel80ae3492009-08-28 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 Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]338}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]339</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]340</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]341
Bill Wendlinge9353d72009-05-17 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 Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]347
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]348<p>Compile unit descriptors provide the root context for objects declared in a
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]349 specific compilation unit. File descriptors are defined using this context.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]350
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]351</div>
352
353<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]354<h4>
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]355 <a name="format_files">File descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]356</h4>
Devang Patel59445db2010-03-09 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 Criswell2a4b0802010-03-17 15:01:50 +0000[diff] [blame]372<p>These descriptors contain information for a file. Global variables and top
Devang Patel59445db2010-03-09 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 Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]379
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]380</div>
381
382<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]383<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]384 <a name="format_global_variables">Global variable descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]385</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]386
387<div class="doc_text">
388
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]389<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]390<pre>
Devang Patel80ae3492009-08-28 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 Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]399 metadata, ;; Reference to file where defined
Devang Patel80ae3492009-08-28 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 Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]404 {}* ;; Reference to the global variable
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]405}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]406</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]407</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]408
409<p>These descriptors provide debug information about globals variables. The
Devang Patel1c6b6812011-03-29 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 Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]412
413</div>
414
415<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]416<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]417 <a name="format_subprograms">Subprogram descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]418</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]419
420<div class="doc_text">
421
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]422<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]423<pre>
Devang Patel80ae3492009-08-28 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 Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]432 metadata, ;; Reference to file where defined
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]433 i32, ;; Line number where defined
434 metadata, ;; Reference to type descriptor
435 i1, ;; True if the global is local to compile unit (static)
Devang Patel1d6bbd42011-04-22 23:10:17 +0000[diff] [blame]436 i1, ;; True if the global is defined in the compile unit (not extern)
437 i32, ;; Virtuality, e.g. dwarf::DW_VIRTUALITY__virtual
438 i32, ;; Index into a virtual function
Devang Patele89b7592010-06-04 22:49:55 +0000[diff] [blame]439 metadata, ;; indicates which base type contains the vtable pointer for the
440 ;; derived class
Devang Patel1d6bbd42011-04-22 23:10:17 +0000[diff] [blame]441 i1, ;; isArtificial
442 i1, ;; isOptimized
443 Function *,;; Pointer to LLVM function
444 metadata, ;; Lists function template parameters
445 metadata ;; Function declaration descriptor
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]446}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]447</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]448</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]449
450<p>These descriptors provide debug information about functions, methods and
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]451 subprograms. They provide details such as name, return types and the source
Devang Patel1c6b6812011-03-29 17:27:08 +0000[diff] [blame]452 location where the subprogram is defined.
453 All subprogram descriptors are collected by a named metadata
454 <tt>!llvm.dbg.sp</tt>.
455</p>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]456
457</div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]458
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]459<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]460<h4>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]461 <a name="format_blocks">Block descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]462</h4>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]463
464<div class="doc_text">
465
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]466<div class="doc_code">
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]467<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]468!3 = metadata !{
Devang Patel9fbc6802010-10-04 16:51:59 +0000[diff] [blame]469 i32, ;; Tag = 11 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block)
Devang Patelcac38902010-10-01 22:45:00 +0000[diff] [blame]470 metadata,;; Reference to context descriptor
471 i32, ;; Line number
Devang Patelfb30b852011-03-08 16:25:29 +0000[diff] [blame]472 i32, ;; Column number
473 metadata,;; Reference to source file
474 i32 ;; Unique ID to identify blocks from a template function
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]475}
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]476</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]477</div>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]478
479<p>These descriptors provide debug information about nested blocks within a
Devang Patelcac38902010-10-01 22:45:00 +0000[diff] [blame]480 subprogram. The line number and column numbers are used to dinstinguish
481 two lexical blocks at same depth. </p>
Jim Laskey9dcffe72006-03-15 19:10:52 +0000[diff] [blame]482
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]483</div>
484
485<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]486<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]487 <a name="format_basic_type">Basic type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]488</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]489
490<div class="doc_text">
491
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]492<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]493<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]494!4 = metadata !{
495 i32, ;; Tag = 36 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
496 ;; (DW_TAG_base_type)
497 metadata, ;; Reference to context (typically a compile unit)
498 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]499 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]500 i32, ;; Line number where defined (may be 0)
501 i64, ;; Size in bits
502 i64, ;; Alignment in bits
503 i64, ;; Offset in bits
504 i32, ;; Flags
505 i32 ;; DWARF type encoding
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]506}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]507</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]508</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]509
510<p>These descriptors define primitive types used in the code. Example int, bool
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]511 and float. The context provides the scope of the type, which is usually the
512 top level. Since basic types are not usually user defined the compile unit
513 and line number can be left as NULL and 0. The size, alignment and offset
514 are expressed in bits and can be 64 bit values. The alignment is used to
515 round the offset when embedded in a
516 <a href="#format_composite_type">composite type</a> (example to keep float
517 doubles on 64 bit boundaries.) The offset is the bit offset if embedded in
518 a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]519
520<p>The type encoding provides the details of the type. The values are typically
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]521 one of the following:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]522
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]523<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]524<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]525DW_ATE_address = 1
526DW_ATE_boolean = 2
527DW_ATE_float = 4
528DW_ATE_signed = 5
529DW_ATE_signed_char = 6
530DW_ATE_unsigned = 7
531DW_ATE_unsigned_char = 8
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]532</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]533</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]534
535</div>
536
537<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]538<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]539 <a name="format_derived_type">Derived type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]540</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]541
542<div class="doc_text">
543
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]544<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]545<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]546!5 = metadata !{
547 i32, ;; Tag (see below)
548 metadata, ;; Reference to context
549 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]550 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]551 i32, ;; Line number where defined (may be 0)
Devang Patelbed5e7d2010-10-01 19:19:30 +0000[diff] [blame]552 i64, ;; Size in bits
553 i64, ;; Alignment in bits
554 i64, ;; Offset in bits
Devang Patel514b4002011-04-16 00:11:51 +0000[diff] [blame]555 metadata, ;; Reference to type derived from
556 metadata, ;; (optional) Name of the Objective C property assoicated with
557 ;; Objective-C an ivar
558 metadata, ;; (optional) Name of the Objective C property getter selector.
559 metadata, ;; (optional) Name of the Objective C property setter selector.
560 i32 ;; (optional) Objective C property attributes.
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]561}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]562</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]563</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]564
565<p>These descriptors are used to define types derived from other types. The
566value of the tag varies depending on the meaning. The following are possible
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]567tag values:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]568
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]569<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]570<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]571DW_TAG_formal_parameter = 5
572DW_TAG_member = 13
573DW_TAG_pointer_type = 15
574DW_TAG_reference_type = 16
575DW_TAG_typedef = 22
576DW_TAG_const_type = 38
577DW_TAG_volatile_type = 53
578DW_TAG_restrict_type = 55
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]579</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]580</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]581
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]582<p><tt>DW_TAG_member</tt> is used to define a member of
583 a <a href="#format_composite_type">composite type</a>
584 or <a href="#format_subprograms">subprogram</a>. The type of the member is
585 the <a href="#format_derived_type">derived
586 type</a>. <tt>DW_TAG_formal_parameter</tt> is used to define a member which
587 is a formal argument of a subprogram.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]588
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]589<p><tt>DW_TAG_typedef</tt> is used to provide a name for the derived type.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]590
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]591<p><tt>DW_TAG_pointer_type</tt>,<tt>DW_TAG_reference_type</tt>,
592 <tt>DW_TAG_const_type</tt>, <tt>DW_TAG_volatile_type</tt>
593 and <tt>DW_TAG_restrict_type</tt> are used to qualify
594 the <a href="#format_derived_type">derived type</a>. </p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]595
596<p><a href="#format_derived_type">Derived type</a> location can be determined
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]597 from the compile unit and line number. The size, alignment and offset are
598 expressed in bits and can be 64 bit values. The alignment is used to round
599 the offset when embedded in a <a href="#format_composite_type">composite
600 type</a> (example to keep float doubles on 64 bit boundaries.) The offset is
601 the bit offset if embedded in a <a href="#format_composite_type">composite
602 type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]603
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]604<p>Note that the <tt>void *</tt> type is expressed as a type derived from NULL.
605</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]606
607</div>
608
609<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]610<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]611 <a name="format_composite_type">Composite type descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]612</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]613
614<div class="doc_text">
615
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]616<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]617<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]618!6 = metadata !{
619 i32, ;; Tag (see below)
620 metadata, ;; Reference to context
621 metadata, ;; Name (may be "" for anonymous types)
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]622 metadata, ;; Reference to file where defined (may be NULL)
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]623 i32, ;; Line number where defined (may be 0)
624 i64, ;; Size in bits
625 i64, ;; Alignment in bits
626 i64, ;; Offset in bits
627 i32, ;; Flags
628 metadata, ;; Reference to type derived from
629 metadata, ;; Reference to array of member descriptors
630 i32 ;; Runtime languages
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]631}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]632</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]633</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]634
635<p>These descriptors are used to define types that are composed of 0 or more
636elements. The value of the tag varies depending on the meaning. The following
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]637are possible tag values:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]638
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]639<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]640<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]641DW_TAG_array_type = 1
642DW_TAG_enumeration_type = 4
643DW_TAG_structure_type = 19
644DW_TAG_union_type = 23
645DW_TAG_vector_type = 259
Bruno Cardoso Lopes9d809ca2009-05-29 17:08:57 +0000[diff] [blame]646DW_TAG_subroutine_type = 21
647DW_TAG_inheritance = 28
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]648</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]649</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]650
Jim Laskey19f964e2006-06-15 20:51:43 +0000[diff] [blame]651<p>The vector flag indicates that an array type is a native packed vector.</p>
652
Jim Laskeyb2ff2d42006-06-16 13:14:03 +0000[diff] [blame]653<p>The members of array types (tag = <tt>DW_TAG_array_type</tt>) or vector types
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]654 (tag = <tt>DW_TAG_vector_type</tt>) are <a href="#format_subrange">subrange
655 descriptors</a>, each representing the range of subscripts at that level of
656 indexing.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]657
658<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]659 <a href="#format_enumeration">enumerator descriptors</a>, each representing
Devang Patel1c6b6812011-03-29 17:27:08 +0000[diff] [blame]660 the definition of enumeration value for the set. All enumeration type
661 descriptors are collected by named metadata <tt>!llvm.dbg.enum</tt>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]662
663<p>The members of structure (tag = <tt>DW_TAG_structure_type</tt>) or union (tag
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]664 = <tt>DW_TAG_union_type</tt>) types are any one of
665 the <a href="#format_basic_type">basic</a>,
666 <a href="#format_derived_type">derived</a>
667 or <a href="#format_composite_type">composite</a> type descriptors, each
668 representing a field member of the structure or union.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]669
Jim Laskey4771cca2006-08-21 21:21:06 +0000[diff] [blame]670<p>For C++ classes (tag = <tt>DW_TAG_structure_type</tt>), member descriptors
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]671 provide information about base classes, static members and member
672 functions. If a member is a <a href="#format_derived_type">derived type
673 descriptor</a> and has a tag of <tt>DW_TAG_inheritance</tt>, then the type
674 represents a base class. If the member of is
675 a <a href="#format_global_variables">global variable descriptor</a> then it
676 represents a static member. And, if the member is
677 a <a href="#format_subprograms">subprogram descriptor</a> then it represents
678 a member function. For static members and member
679 functions, <tt>getName()</tt> returns the members link or the C++ mangled
680 name. <tt>getDisplayName()</tt> the simplied version of the name.</p>
Jim Laskey4771cca2006-08-21 21:21:06 +0000[diff] [blame]681
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]682<p>The first member of subroutine (tag = <tt>DW_TAG_subroutine_type</tt>) type
683 elements is the return type for the subroutine. The remaining elements are
684 the formal arguments to the subroutine.</p>
Jim Laskey4810c262006-06-20 21:13:20 +0000[diff] [blame]685
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]686<p><a href="#format_composite_type">Composite type</a> location can be
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]687 determined from the compile unit and line number. The size, alignment and
688 offset are expressed in bits and can be 64 bit values. The alignment is used
689 to round the offset when embedded in
690 a <a href="#format_composite_type">composite type</a> (as an example, to keep
691 float doubles on 64 bit boundaries.) The offset is the bit offset if embedded
692 in a <a href="#format_composite_type">composite type</a>.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]693
694</div>
695
696<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]697<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]698 <a name="format_subrange">Subrange descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]699</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]700
701<div class="doc_text">
702
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]703<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]704<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]705!42 = metadata !{
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]706 i32, ;; Tag = 33 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subrange_type)
707 i64, ;; Low value
708 i64 ;; High value
709}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]710</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]711</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]712
713<p>These descriptors are used to define ranges of array subscripts for an array
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]714 <a href="#format_composite_type">composite type</a>. The low value defines
715 the lower bounds typically zero for C/C++. The high value is the upper
716 bounds. Values are 64 bit. High - low + 1 is the size of the array. If low
Devang Patel778947c2011-04-08 23:39:38 +0000[diff] [blame]717 > high the array bounds are not included in generated debugging information.
718</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]719
720</div>
721
722<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]723<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]724 <a name="format_enumeration">Enumerator descriptors</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]725</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]726
727<div class="doc_text">
728
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]729<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]730<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]731!6 = metadata !{
732 i32, ;; Tag = 40 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
733 ;; (DW_TAG_enumerator)
734 metadata, ;; Name
735 i64 ;; Value
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]736}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]737</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]738</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]739
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]740<p>These descriptors are used to define members of an
741 enumeration <a href="#format_composite_type">composite type</a>, it
742 associates the name to the value.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]743
744</div>
745
746<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]747<h4>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]748 <a name="format_variables">Local variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]749</h4>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]750
751<div class="doc_text">
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]752
753<div class="doc_code">
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]754<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]755!7 = metadata !{
756 i32, ;; Tag (see below)
757 metadata, ;; Context
758 metadata, ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]759 metadata, ;; Reference to file where defined
Devang Patele1aa67c2011-03-08 16:29:40 +0000[diff] [blame]760 i32, ;; 24 bit - Line number where defined
761 ;; 8 bit - Argument number. 1 indicates 1st argument.
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]762 metadata ;; Type descriptor
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]763}
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]764</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]765</div>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]766
767<p>These descriptors are used to define variables local to a sub program. The
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]768 value of the tag depends on the usage of the variable:</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]769
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]770<div class="doc_code">
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]771<pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]772DW_TAG_auto_variable = 256
773DW_TAG_arg_variable = 257
774DW_TAG_return_variable = 258
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]775</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]776</div>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]777
778<p>An auto variable is any variable declared in the body of the function. An
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]779 argument variable is any variable that appears as a formal argument to the
780 function. A return variable is used to track the result of a function and
781 has no source correspondent.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]782
Jim Laskey3481e122006-03-24 09:20:27 +0000[diff] [blame]783<p>The context is either the subprogram or block where the variable is defined.
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]784 Name the source variable name. Compile unit and line indicate where the
785 variable was defined. Type descriptor defines the declared type of the
786 variable.</p>
Jim Laskey5dcfd562006-03-23 17:54:33 +0000[diff] [blame]787
788</div>
789
790<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]791<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]792 <a name="format_common_intrinsics">Debugger intrinsic functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]793</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]794
795<div class="doc_text">
796
797<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]798 provide debug information at various points in generated code.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]799
800</div>
801
802<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]803<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]804 <a name="format_common_declare">llvm.dbg.declare</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]805</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]806
807<div class="doc_text">
808<pre>
Devang Patel6df452c2010-10-01 19:22:16 +0000[diff] [blame]809 void %<a href="#format_common_declare">llvm.dbg.declare</a>(metadata, metadata)
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]810</pre>
811
Jim Laskey3481e122006-03-24 09:20:27 +0000[diff] [blame]812<p>This intrinsic provides information about a local element (ex. variable.) The
NAKAMURA Takumi6bd36d52011-04-09 09:51:57 +0000[diff] [blame]813 first argument is metadata holding alloca for the variable. The
Devang Patel9a8539c2011-02-01 17:22:12 +0000[diff] [blame]814 second argument is metadata containing description of the variable. </p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]815</div>
816
817<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]818<h4>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]819 <a name="format_common_value">llvm.dbg.value</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]820</h4>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]821
822<div class="doc_text">
823<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]824 void %<a href="#format_common_value">llvm.dbg.value</a>(metadata, i64, metadata)
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]825</pre>
826
827<p>This intrinsic provides information when a user source variable is set to a
828 new value. The first argument is the new value (wrapped as metadata). The
829 second argument is the offset in the user source variable where the new value
Devang Patel9a8539c2011-02-01 17:22:12 +0000[diff] [blame]830 is written. The third argument is metadata containing description of the
831 user source variable. </p>
Victor Hernandez0b62cc62010-01-11 22:53:48 +0000[diff] [blame]832</div>
833
834<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]835<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]836 <a name="format_common_lifetime">Object lifetimes and scoping</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]837</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]838
839<div class="doc_text">
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]840<p>In many languages, the local variables in functions can have their lifetimes
841 or scopes limited to a subset of a function. In the C family of languages,
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]842 for example, variables are only live (readable and writable) within the
843 source block that they are defined in. In functional languages, values are
844 only readable after they have been defined. Though this is a very obvious
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]845 concept, it is non-trivial to model in LLVM, because it has no notion of
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]846 scoping in this sense, and does not want to be tied to a language's scoping
847 rules.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]848
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]849<p>In order to handle this, the LLVM debug format uses the metadata attached to
Nick Lewyckya87014f2010-03-31 07:50:17 +0000[diff] [blame]850 llvm instructions to encode line number and scoping information. Consider
851 the following C fragment, for example:</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]852
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]853<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]854<pre>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]8551. void foo() {
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]8562. int X = 21;
8573. int Y = 22;
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]8584. {
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]8595. int Z = 23;
8606. Z = X;
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]8617. }
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]8628. X = Y;
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]8639. }
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]864</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]865</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]866
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]867<p>Compiled to LLVM, this function would be represented like this:</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]868
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]869<div class="doc_code">
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]870<pre>
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]871define void @foo() nounwind ssp {
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]872entry:
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]873 %X = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
874 %Y = alloca i32, align 4 ; &lt;i32*&gt; [#uses=4]
875 %Z = alloca i32, align 4 ; &lt;i32*&gt; [#uses=3]
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]876 %0 = bitcast i32* %X to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]877 call void @llvm.dbg.declare(metadata !{i32 * %X}, metadata !0), !dbg !7
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]878 store i32 21, i32* %X, !dbg !8
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]879 %1 = bitcast i32* %Y to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]880 call void @llvm.dbg.declare(metadata !{i32 * %Y}, metadata !9), !dbg !10
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]881 store i32 22, i32* %Y, !dbg !11
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]882 %2 = bitcast i32* %Z to {}* ; &lt;{}*&gt; [#uses=1]
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]883 call void @llvm.dbg.declare(metadata !{i32 * %Z}, metadata !12), !dbg !14
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]884 store i32 23, i32* %Z, !dbg !15
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]885 %tmp = load i32* %X, !dbg !16 ; &lt;i32&gt; [#uses=1]
886 %tmp1 = load i32* %Y, !dbg !16 ; &lt;i32&gt; [#uses=1]
887 %add = add nsw i32 %tmp, %tmp1, !dbg !16 ; &lt;i32&gt; [#uses=1]
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]888 store i32 %add, i32* %Z, !dbg !16
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]889 %tmp2 = load i32* %Y, !dbg !17 ; &lt;i32&gt; [#uses=1]
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]890 store i32 %tmp2, i32* %X, !dbg !17
891 ret void, !dbg !18
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]892}
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]893
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]894declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]895
896!0 = metadata !{i32 459008, metadata !1, metadata !"X",
897 metadata !3, i32 2, metadata !6}; [ DW_TAG_auto_variable ]
898!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
899!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo", metadata !"foo",
900 metadata !"foo", metadata !3, i32 1, metadata !4,
901 i1 false, i1 true}; [DW_TAG_subprogram ]
902!3 = metadata !{i32 458769, i32 0, i32 12, metadata !"foo.c",
903 metadata !"/private/tmp", metadata !"clang 1.1", i1 true,
904 i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
905!4 = metadata !{i32 458773, metadata !3, metadata !"", null, i32 0, i64 0, i64 0,
906 i64 0, i32 0, null, metadata !5, i32 0}; [DW_TAG_subroutine_type ]
907!5 = metadata !{null}
908!6 = metadata !{i32 458788, metadata !3, metadata !"int", metadata !3, i32 0,
909 i64 32, i64 32, i64 0, i32 0, i32 5}; [DW_TAG_base_type ]
910!7 = metadata !{i32 2, i32 7, metadata !1, null}
911!8 = metadata !{i32 2, i32 3, metadata !1, null}
912!9 = metadata !{i32 459008, metadata !1, metadata !"Y", metadata !3, i32 3,
913 metadata !6}; [ DW_TAG_auto_variable ]
914!10 = metadata !{i32 3, i32 7, metadata !1, null}
915!11 = metadata !{i32 3, i32 3, metadata !1, null}
916!12 = metadata !{i32 459008, metadata !13, metadata !"Z", metadata !3, i32 5,
917 metadata !6}; [ DW_TAG_auto_variable ]
918!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
919!14 = metadata !{i32 5, i32 9, metadata !13, null}
920!15 = metadata !{i32 5, i32 5, metadata !13, null}
921!16 = metadata !{i32 6, i32 5, metadata !13, null}
922!17 = metadata !{i32 8, i32 3, metadata !1, null}
923!18 = metadata !{i32 9, i32 1, metadata !2, null}
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]924</pre>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]925</div>
926
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]927<p>This example illustrates a few important details about LLVM debugging
928 information. In particular, it shows how the <tt>llvm.dbg.declare</tt>
929 intrinsic and location information, which are attached to an instruction,
930 are applied together to allow a debugger to analyze the relationship between
931 statements, variable definitions, and the code used to implement the
932 function.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]933
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]934<div class="doc_code">
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]935<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]936call void @llvm.dbg.declare(metadata, metadata !0), !dbg !7
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]937</pre>
938</div>
939
940<p>The first intrinsic
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]941 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]942 encodes debugging information for the variable <tt>X</tt>. The metadata
943 <tt>!dbg !7</tt> attached to the intrinsic provides scope information for the
944 variable <tt>X</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]945
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]946<div class="doc_code">
947<pre>
948!7 = metadata !{i32 2, i32 7, metadata !1, null}
949!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
950!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"foo",
951 metadata !"foo", metadata !"foo", metadata !3, i32 1,
952 metadata !4, i1 false, i1 true}; [DW_TAG_subprogram ]
953</pre>
954</div>
955
956<p>Here <tt>!7</tt> is metadata providing location information. It has four
957 fields: line number, column number, scope, and original scope. The original
958 scope represents inline location if this instruction is inlined inside a
959 caller, and is null otherwise. In this example, scope is encoded by
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]960 <tt>!1</tt>. <tt>!1</tt> represents a lexical block inside the scope
961 <tt>!2</tt>, where <tt>!2</tt> is a
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]962 <a href="#format_subprograms">subprogram descriptor</a>. This way the
963 location information attached to the intrinsics indicates that the
964 variable <tt>X</tt> is declared at line number 2 at a function level scope in
965 function <tt>foo</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]966
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]967<p>Now lets take another example.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]968
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]969<div class="doc_code">
Bill Wendling05252352009-12-01 00:59:58 +0000[diff] [blame]970<pre>
Devang Patel7846c1e2011-02-03 00:22:17 +0000[diff] [blame]971call void @llvm.dbg.declare(metadata, metadata !12), !dbg !14
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]972</pre>
973</div>
974
975<p>The second intrinsic
Devang Patel4da997b2009-11-25 23:28:01 +0000[diff] [blame]976 <tt>%<a href="#format_common_declare">llvm.dbg.declare</a></tt>
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]977 encodes debugging information for variable <tt>Z</tt>. The metadata
978 <tt>!dbg !14</tt> attached to the intrinsic provides scope information for
979 the variable <tt>Z</tt>.</p>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]980
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]981<div class="doc_code">
982<pre>
983!13 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
984!14 = metadata !{i32 5, i32 9, metadata !13, null}
985</pre>
986</div>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]987
John Criswell2a4b0802010-03-17 15:01:50 +0000[diff] [blame]988<p>Here <tt>!14</tt> indicates that <tt>Z</tt> is declared at line number 5 and
Bill Wendling991b84e2009-12-01 00:53:11 +0000[diff] [blame]989 column number 9 inside of lexical scope <tt>!13</tt>. The lexical scope
990 itself resides inside of lexical scope <tt>!1</tt> described above.</p>
991
992<p>The scope information attached with each instruction provides a
993 straightforward way to find instructions covered by a scope.</p>
994
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]995</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]996
997<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]998<h2>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]999 <a name="ccxx_frontend">C/C++ front-end specific debug information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1000</h2>
Misha Brukmancda6a9b2004-12-09 20:27:37 +0000[diff] [blame]1001<!-- *********************************************************************** -->
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1002
1003<div class="doc_text">
1004
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1005<p>The C and C++ front-ends represent information about the program in a format
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1006 that is effectively identical
1007 to <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3.0</a> in
1008 terms of information content. This allows code generators to trivially
1009 support native debuggers by generating standard dwarf information, and
1010 contains enough information for non-dwarf targets to translate it as
1011 needed.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1012
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1013<p>This section describes the forms used to represent C and C++ programs. Other
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1014 languages could pattern themselves after this (which itself is tuned to
1015 representing programs in the same way that DWARF 3 does), or they could
1016 choose to provide completely different forms if they don't fit into the DWARF
1017 model. As support for debugging information gets added to the various LLVM
1018 source-language front-ends, the information used should be documented
1019 here.</p>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1020
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1021<p>The following sections provide examples of various C/C++ constructs and the
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1022 debug information that would best describe those constructs.</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1023
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1024</div>
1025
1026<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1027<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1028 <a name="ccxx_compile_units">C/C++ source file information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1029</h3>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1030
1031<div class="doc_text">
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1032
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1033<p>Given the source files <tt>MySource.cpp</tt> and <tt>MyHeader.h</tt> located
1034 in the directory <tt>/Users/mine/sources</tt>, the following code:</p>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1035
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1036<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1037<pre>
1038#include "MyHeader.h"
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1039
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1040int main(int argc, char *argv[]) {
1041 return 0;
1042}
1043</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1044</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1045
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1046<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1047
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1048<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1049<pre>
1050...
1051;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1052;; Define the compile unit for the main source file "/Users/mine/sources/MySource.cpp".
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1053;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1054!2 = metadata !{
1055 i32 524305, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1056 i32 0, ;; Unused
1057 i32 4, ;; Language Id
1058 metadata !"MySource.cpp",
1059 metadata !"/Users/mine/sources",
1060 metadata !"4.2.1 (Based on Apple Inc. build 5649) (LLVM build 00)",
1061 i1 true, ;; Main Compile Unit
1062 i1 false, ;; Optimized compile unit
1063 metadata !"", ;; Compiler flags
1064 i32 0} ;; Runtime version
1065
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1066;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1067;; Define the file for the file "/Users/mine/sources/MySource.cpp".
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1068;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1069!1 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1070 i32 524329, ;; Tag
1071 metadata !"MySource.cpp",
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1072 metadata !"/Users/mine/sources",
Devang Patel4a7904d62010-07-13 16:53:20 +0000[diff] [blame]1073 metadata !2 ;; Compile unit
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1074}
1075
1076;;
1077;; Define the file for the file "/Users/mine/sources/Myheader.h"
1078;;
1079!3 = metadata !{
1080 i32 524329, ;; Tag
1081 metadata !"Myheader.h"
1082 metadata !"/Users/mine/sources",
Devang Patel4a7904d62010-07-13 16:53:20 +0000[diff] [blame]1083 metadata !2 ;; Compile unit
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1084}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1085
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1086...
1087</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1088</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1089
Devang Patel5bc1c4b2010-03-26 19:08:36 +0000[diff] [blame]1090<p>llvm::Instruction provides easy access to metadata attached with an
1091instruction. One can extract line number information encoded in LLVM IR
1092using <tt>Instruction::getMetadata()</tt> and
1093<tt>DILocation::getLineNumber()</tt>.
1094<pre>
1095 if (MDNode *N = I->getMetadata("dbg")) { // Here I is an LLVM instruction
1096 DILocation Loc(N); // DILocation is in DebugInfo.h
1097 unsigned Line = Loc.getLineNumber();
1098 StringRef File = Loc.getFilename();
1099 StringRef Dir = Loc.getDirectory();
1100 }
1101</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1102</div>
1103
1104<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1105<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1106 <a name="ccxx_global_variable">C/C++ global variable information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1107</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1108
1109<div class="doc_text">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1110
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1111<p>Given an integer global variable declared as follows:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1112
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1113<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1114<pre>
1115int MyGlobal = 100;
1116</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1117</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1118
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1119<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1120
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1121<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1122<pre>
1123;;
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1124;; Define the global itself.
1125;;
1126%MyGlobal = global int 100
1127...
1128;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1129;; List of debug info of globals
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1130;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1131!llvm.dbg.gv = !{!0}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1132
1133;;
1134;; Define the global variable descriptor. Note the reference to the global
1135;; variable anchor and the global variable itself.
1136;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1137!0 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1138 i32 524340, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1139 i32 0, ;; Unused
1140 metadata !1, ;; Context
1141 metadata !"MyGlobal", ;; Name
1142 metadata !"MyGlobal", ;; Display Name
1143 metadata !"MyGlobal", ;; Linkage Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1144 metadata !3, ;; Compile Unit
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1145 i32 1, ;; Line Number
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1146 metadata !4, ;; Type
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1147 i1 false, ;; Is a local variable
1148 i1 true, ;; Is this a definition
1149 i32* @MyGlobal ;; The global variable
1150}
1151
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1152;;
1153;; Define the basic type of 32 bit signed integer. Note that since int is an
1154;; intrinsic type the source file is NULL and line 0.
1155;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1156!4 = metadata !{
1157 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1158 metadata !1, ;; Context
1159 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1160 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1161 i32 0, ;; Line number
1162 i64 32, ;; Size in Bits
1163 i64 32, ;; Align in Bits
1164 i64 0, ;; Offset in Bits
1165 i32 0, ;; Flags
1166 i32 5 ;; Encoding
1167}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1168
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1169</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1170</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1171
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]1172</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1173
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1174<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1175<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1176 <a name="ccxx_subprogram">C/C++ function information</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1177</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1178
1179<div class="doc_text">
1180
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1181<p>Given a function declared as follows:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1182
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1183<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1184<pre>
1185int main(int argc, char *argv[]) {
1186 return 0;
1187}
1188</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1189</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1190
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1191<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1192
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1193<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1194<pre>
1195;;
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1196;; Define the anchor for subprograms. Note that the second field of the
1197;; anchor is 46, which is the same as the tag for subprograms
1198;; (46 = DW_TAG_subprogram.)
1199;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1200!6 = metadata !{
1201 i32 524334, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1202 i32 0, ;; Unused
1203 metadata !1, ;; Context
1204 metadata !"main", ;; Name
1205 metadata !"main", ;; Display name
1206 metadata !"main", ;; Linkage name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1207 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1208 i32 1, ;; Line number
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1209 metadata !4, ;; Type
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1210 i1 false, ;; Is local
Devang Patel9f738842011-04-05 22:52:06 +0000[diff] [blame]1211 i1 true, ;; Is definition
1212 i32 0, ;; Virtuality attribute, e.g. pure virtual function
1213 i32 0, ;; Index into virtual table for C++ methods
1214 i32 0, ;; Type that holds virtual table.
1215 i32 0, ;; Flags
1216 i1 false, ;; True if this function is optimized
1217 Function *, ;; Pointer to llvm::Function
1218 null ;; Function template parameters
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1219}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1220;;
1221;; Define the subprogram itself.
1222;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1223define i32 @main(i32 %argc, i8** %argv) {
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1224...
1225}
1226</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1227</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1228
1229</div>
1230
1231<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1232<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1233 <a name="ccxx_basic_types">C/C++ basic types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1234</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1235
1236<div class="doc_text">
1237
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1238<p>The following are the basic type descriptors for C/C++ core types:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1239
1240</div>
1241
1242<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1243<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1244 <a name="ccxx_basic_type_bool">bool</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1245</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1246
1247<div class="doc_text">
1248
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1249<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1250<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1251!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1252 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1253 metadata !1, ;; Context
1254 metadata !"bool", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1255 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1256 i32 0, ;; Line number
1257 i64 8, ;; Size in Bits
1258 i64 8, ;; Align in Bits
1259 i64 0, ;; Offset in Bits
1260 i32 0, ;; Flags
1261 i32 2 ;; Encoding
1262}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1263</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1264</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1265
1266</div>
1267
1268<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1269<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1270 <a name="ccxx_basic_char">char</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1271</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1272
1273<div class="doc_text">
1274
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1275<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1276<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1277!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1278 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1279 metadata !1, ;; Context
1280 metadata !"char", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1281 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1282 i32 0, ;; Line number
1283 i64 8, ;; Size in Bits
1284 i64 8, ;; Align in Bits
1285 i64 0, ;; Offset in Bits
1286 i32 0, ;; Flags
1287 i32 6 ;; Encoding
1288}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1289</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1290</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1291
1292</div>
1293
1294<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1295<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1296 <a name="ccxx_basic_unsigned_char">unsigned char</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1297</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1298
1299<div class="doc_text">
1300
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1301<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1302<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1303!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1304 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1305 metadata !1, ;; Context
1306 metadata !"unsigned char",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1307 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1308 i32 0, ;; Line number
1309 i64 8, ;; Size in Bits
1310 i64 8, ;; Align in Bits
1311 i64 0, ;; Offset in Bits
1312 i32 0, ;; Flags
1313 i32 8 ;; Encoding
1314}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1315</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1316</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1317
1318</div>
1319
1320<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1321<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1322 <a name="ccxx_basic_short">short</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1323</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1324
1325<div class="doc_text">
1326
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1327<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1328<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1329!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1330 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1331 metadata !1, ;; Context
1332 metadata !"short int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1333 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1334 i32 0, ;; Line number
1335 i64 16, ;; Size in Bits
1336 i64 16, ;; Align in Bits
1337 i64 0, ;; Offset in Bits
1338 i32 0, ;; Flags
1339 i32 5 ;; Encoding
1340}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1341</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1342</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1343
1344</div>
1345
1346<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1347<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1348 <a name="ccxx_basic_unsigned_short">unsigned short</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1349</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1350
1351<div class="doc_text">
1352
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1353<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1354<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1355!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1356 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1357 metadata !1, ;; Context
1358 metadata !"short unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1359 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1360 i32 0, ;; Line number
1361 i64 16, ;; Size in Bits
1362 i64 16, ;; Align in Bits
1363 i64 0, ;; Offset in Bits
1364 i32 0, ;; Flags
1365 i32 7 ;; Encoding
1366}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1367</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1368</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1369
1370</div>
1371
1372<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1373<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1374 <a name="ccxx_basic_int">int</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1375</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1376
1377<div class="doc_text">
1378
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1379<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1380<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1381!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1382 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1383 metadata !1, ;; Context
1384 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1385 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1386 i32 0, ;; Line number
1387 i64 32, ;; Size in Bits
1388 i64 32, ;; Align in Bits
1389 i64 0, ;; Offset in Bits
1390 i32 0, ;; Flags
1391 i32 5 ;; Encoding
1392}
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1393</pre></div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1394
1395</div>
1396
1397<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1398<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1399 <a name="ccxx_basic_unsigned_int">unsigned int</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1400</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1401
1402<div class="doc_text">
1403
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1404<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1405<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1406!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1407 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1408 metadata !1, ;; Context
1409 metadata !"unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1410 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1411 i32 0, ;; Line number
1412 i64 32, ;; Size in Bits
1413 i64 32, ;; Align in Bits
1414 i64 0, ;; Offset in Bits
1415 i32 0, ;; Flags
1416 i32 7 ;; Encoding
1417}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1418</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1419</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1420
1421</div>
1422
1423<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1424<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1425 <a name="ccxx_basic_long_long">long long</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1426</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1427
1428<div class="doc_text">
1429
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1430<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1431<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1432!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1433 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1434 metadata !1, ;; Context
1435 metadata !"long long int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1436 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1437 i32 0, ;; Line number
1438 i64 64, ;; Size in Bits
1439 i64 64, ;; Align in Bits
1440 i64 0, ;; Offset in Bits
1441 i32 0, ;; Flags
1442 i32 5 ;; Encoding
1443}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1444</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1445</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1446
1447</div>
1448
1449<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1450<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1451 <a name="ccxx_basic_unsigned_long_long">unsigned long long</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1452</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1453
1454<div class="doc_text">
1455
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1456<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1457<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1458!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1459 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1460 metadata !1, ;; Context
1461 metadata !"long long unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1462 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1463 i32 0, ;; Line number
1464 i64 64, ;; Size in Bits
1465 i64 64, ;; Align in Bits
1466 i64 0, ;; Offset in Bits
1467 i32 0, ;; Flags
1468 i32 7 ;; Encoding
1469}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1470</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1471</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1472
1473</div>
1474
1475<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1476<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1477 <a name="ccxx_basic_float">float</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1478</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1479
1480<div class="doc_text">
1481
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1482<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1483<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1484!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1485 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1486 metadata !1, ;; Context
1487 metadata !"float",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1488 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1489 i32 0, ;; Line number
1490 i64 32, ;; Size in Bits
1491 i64 32, ;; Align in Bits
1492 i64 0, ;; Offset in Bits
1493 i32 0, ;; Flags
1494 i32 4 ;; Encoding
1495}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1496</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1497</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1498
1499</div>
1500
1501<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1502<h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1503 <a name="ccxx_basic_double">double</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1504</h4>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1505
1506<div class="doc_text">
1507
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1508<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1509<pre>
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1510!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1511 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1512 metadata !1, ;; Context
1513 metadata !"double",;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1514 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1515 i32 0, ;; Line number
1516 i64 64, ;; Size in Bits
1517 i64 64, ;; Align in Bits
1518 i64 0, ;; Offset in Bits
1519 i32 0, ;; Flags
1520 i32 4 ;; Encoding
1521}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1522</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1523</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1524
1525</div>
1526
1527<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1528<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1529 <a name="ccxx_derived_types">C/C++ derived types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1530</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1531
1532<div class="doc_text">
1533
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1534<p>Given the following as an example of C/C++ derived type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1535
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1536<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1537<pre>
1538typedef const int *IntPtr;
1539</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1540</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1541
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1542<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1543
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1544<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1545<pre>
1546;;
1547;; Define the typedef "IntPtr".
1548;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1549!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1550 i32 524310, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1551 metadata !1, ;; Context
1552 metadata !"IntPtr", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1553 metadata !3, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1554 i32 0, ;; Line number
1555 i64 0, ;; Size in bits
1556 i64 0, ;; Align in bits
1557 i64 0, ;; Offset in bits
1558 i32 0, ;; Flags
1559 metadata !4 ;; Derived From type
1560}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1561
1562;;
1563;; Define the pointer type.
1564;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1565!4 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1566 i32 524303, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1567 metadata !1, ;; Context
1568 metadata !"", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1569 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1570 i32 0, ;; Line number
1571 i64 64, ;; Size in bits
1572 i64 64, ;; Align in bits
1573 i64 0, ;; Offset in bits
1574 i32 0, ;; Flags
1575 metadata !5 ;; Derived From type
1576}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1577;;
1578;; Define the const type.
1579;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1580!5 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1581 i32 524326, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1582 metadata !1, ;; Context
1583 metadata !"", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1584 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1585 i32 0, ;; Line number
1586 i64 32, ;; Size in bits
1587 i64 32, ;; Align in bits
1588 i64 0, ;; Offset in bits
1589 i32 0, ;; Flags
1590 metadata !6 ;; Derived From type
1591}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1592;;
1593;; Define the int type.
1594;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1595!6 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1596 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1597 metadata !1, ;; Context
1598 metadata !"int", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1599 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1600 i32 0, ;; Line number
1601 i64 32, ;; Size in bits
1602 i64 32, ;; Align in bits
1603 i64 0, ;; Offset in bits
1604 i32 0, ;; Flags
1605 5 ;; Encoding
1606}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1607</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1608</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1609
1610</div>
1611
1612<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1613<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1614 <a name="ccxx_composite_types">C/C++ struct/union types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1615</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1616
1617<div class="doc_text">
1618
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1619<p>Given the following as an example of C/C++ struct type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1620
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1621<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1622<pre>
1623struct Color {
1624 unsigned Red;
1625 unsigned Green;
1626 unsigned Blue;
1627};
1628</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1629</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1630
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1631<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1632
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1633<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1634<pre>
1635;;
1636;; Define basic type for unsigned int.
1637;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1638!5 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1639 i32 524324, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1640 metadata !1, ;; Context
1641 metadata !"unsigned int",
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1642 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1643 i32 0, ;; Line number
1644 i64 32, ;; Size in Bits
1645 i64 32, ;; Align in Bits
1646 i64 0, ;; Offset in Bits
1647 i32 0, ;; Flags
1648 i32 7 ;; Encoding
1649}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1650;;
1651;; Define composite type for struct Color.
1652;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1653!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1654 i32 524307, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1655 metadata !1, ;; Context
1656 metadata !"Color", ;; Name
1657 metadata !1, ;; Compile unit
1658 i32 1, ;; Line number
1659 i64 96, ;; Size in bits
1660 i64 32, ;; Align in bits
1661 i64 0, ;; Offset in bits
1662 i32 0, ;; Flags
1663 null, ;; Derived From
1664 metadata !3, ;; Elements
1665 i32 0 ;; Runtime Language
1666}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1667
1668;;
1669;; Define the Red field.
1670;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1671!4 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1672 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1673 metadata !1, ;; Context
1674 metadata !"Red", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1675 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1676 i32 2, ;; Line number
1677 i64 32, ;; Size in bits
1678 i64 32, ;; Align in bits
1679 i64 0, ;; Offset in bits
1680 i32 0, ;; Flags
1681 metadata !5 ;; Derived From type
1682}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1683
1684;;
1685;; Define the Green field.
1686;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1687!6 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1688 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1689 metadata !1, ;; Context
1690 metadata !"Green", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1691 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1692 i32 3, ;; Line number
1693 i64 32, ;; Size in bits
1694 i64 32, ;; Align in bits
1695 i64 32, ;; Offset in bits
1696 i32 0, ;; Flags
1697 metadata !5 ;; Derived From type
1698}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1699
1700;;
1701;; Define the Blue field.
1702;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1703!7 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1704 i32 524301, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1705 metadata !1, ;; Context
1706 metadata !"Blue", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1707 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1708 i32 4, ;; Line number
1709 i64 32, ;; Size in bits
1710 i64 32, ;; Align in bits
1711 i64 64, ;; Offset in bits
1712 i32 0, ;; Flags
1713 metadata !5 ;; Derived From type
1714}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1715
1716;;
1717;; Define the array of fields used by the composite type Color.
1718;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1719!3 = metadata !{metadata !4, metadata !6, metadata !7}
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1720</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1721</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1722
1723</div>
1724
1725<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1726<h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1727 <a name="ccxx_enumeration_types">C/C++ enumeration types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1728</h3>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1729
1730<div class="doc_text">
1731
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1732<p>Given the following as an example of C/C++ enumeration type:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1733
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1734<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1735<pre>
1736enum Trees {
1737 Spruce = 100,
1738 Oak = 200,
1739 Maple = 300
1740};
1741</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1742</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1743
Misha Brukman39dcddf2008-12-16 02:54:22 +0000[diff] [blame]1744<p>a C/C++ front-end would generate the following descriptors:</p>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1745
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1746<div class="doc_code">
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1747<pre>
1748;;
1749;; Define composite type for enum Trees
1750;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1751!2 = metadata !{
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1752 i32 524292, ;; Tag
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1753 metadata !1, ;; Context
1754 metadata !"Trees", ;; Name
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1755 metadata !1, ;; File
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1756 i32 1, ;; Line number
1757 i64 32, ;; Size in bits
1758 i64 32, ;; Align in bits
1759 i64 0, ;; Offset in bits
1760 i32 0, ;; Flags
1761 null, ;; Derived From type
1762 metadata !3, ;; Elements
1763 i32 0 ;; Runtime language
1764}
Devang Patel02aac922009-08-25 05:24:07 +0000[diff] [blame]1765
Devang Patelf08e35d2009-08-26 05:01:18 +0000[diff] [blame]1766;;
1767;; Define the array of enumerators used by composite type Trees.
1768;;
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1769!3 = metadata !{metadata !4, metadata !5, metadata !6}
1770
1771;;
1772;; Define Spruce enumerator.
1773;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1774!4 = metadata !{i32 524328, metadata !"Spruce", i64 100}
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1775
1776;;
1777;; Define Oak enumerator.
1778;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1779!5 = metadata !{i32 524328, metadata !"Oak", i64 200}
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1780
1781;;
1782;; Define Maple enumerator.
1783;;
Devang Patel59445db2010-03-09 00:44:10 +0000[diff] [blame]1784!6 = metadata !{i32 524328, metadata !"Maple", i64 300}
Devang Patel80ae3492009-08-28 23:24:31 +0000[diff] [blame]1785
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1786</pre>
Bill Wendlinge9353d72009-05-17 05:52:39 +0000[diff] [blame]1787</div>
Jim Laskey14edc932006-03-14 18:08:46 +0000[diff] [blame]1788
1789</div>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1790
1791<!-- *********************************************************************** -->
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1792
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1793<hr>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1794<address>
1795 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]1796 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1797 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]1798 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1799
1800 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]1801 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1802 Last modified: $Date$
Misha Brukmanf91d9942004-05-12 19:21:57 +0000[diff] [blame]1803</address>
Chris Lattner1811fca2004-01-05 05:06:33 +0000[diff] [blame]1804
1805</body>
1806</html>