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9
10<div class="doc_title">Source Level Debugging with LLVM</div>
11
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]12<table class="layout" style="width:100%">
13 <tr class="layout">
14 <td class="left">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]15<ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]16 <li><a href="#introduction">Introduction</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]17 <ol>
18 <li><a href="#phil">Philosophy behind LLVM debugging information</a></li>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]19 <li><a href="#consumers">Debug information consumers</a></li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]20 <li><a href="#debugopt">Debugging optimized code</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]21 </ol></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]22 <li><a href="#format">Debugging information format</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]23 <ol>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]24 <li><a href="#debug_info_descriptors">Debug information descriptors</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]25 <ul>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]26 <li><a href="#format_anchors">Anchor descriptors</a></li>
27 <li><a href="#format_compile_units">Compile unit descriptors</a></li>
28 <li><a href="#format_global_variables">Global variable descriptors</a></li>
29 <li><a href="#format_subprograms">Subprogram descriptors</a></li>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]30 <li><a href="#format_blocks">Block descriptors</a></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]31 <li><a href="#format_basic_type">Basic type descriptors</a></li>
32 <li><a href="#format_derived_type">Derived type descriptors</a></li>
33 <li><a href="#format_composite_type">Composite type descriptors</a></li>
34 <li><a href="#format_subrange">Subrange descriptors</a></li>
35 <li><a href="#format_enumeration">Enumerator descriptors</a></li>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]36 <li><a href="#format_variables">Local variables</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]37 </ul></li>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]38 <li><a href="#format_common_intrinsics">Debugger intrinsic functions</a>
39 <ul>
40 <li><a href="#format_common_stoppoint">llvm.dbg.stoppoint</a></li>
41 <li><a href="#format_common_func_start">llvm.dbg.func.start</a></li>
42 <li><a href="#format_common_region_start">llvm.dbg.region.start</a></li>
43 <li><a href="#format_common_region_end">llvm.dbg.region.end</a></li>
44 <li><a href="#format_common_declare">llvm.dbg.declare</a></li>
45 </ul></li>
46 <li><a href="#format_common_stoppoints">Representing stopping points in the
47 source program</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]48 </ol></li>
49 <li><a href="#ccxx_frontend">C/C++ front-end specific debug information</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]50 <ol>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]51 <li><a href="#ccxx_compile_units">C/C++ source file information</a></li>
52 <li><a href="#ccxx_global_variable">C/C++ global variable information</a></li>
53 <li><a href="#ccxx_subprogram">C/C++ function information</a></li>
54 <li><a href="#ccxx_basic_types">C/C++ basic types</a></li>
55 <li><a href="#ccxx_derived_types">C/C++ derived types</a></li>
56 <li><a href="#ccxx_composite_types">C/C++ struct/union types</a></li>
57 <li><a href="#ccxx_enumeration_types">C/C++ enumeration types</a></li>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]58 </ol></li>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]59</ul>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]60</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]61<td class="right">
Misha Brukmane849a1a2004-05-12 21:26:16 +0000[diff] [blame]62<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247"
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]63height="369">
64</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]65</tr></table>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]66
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]67<div class="doc_author">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]68 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
69 and <a href="mailto:jlaskey@apple.com">Jim Laskey</a></p>
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]70</div>
71
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]72
73<!-- *********************************************************************** -->
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]74<div class="doc_section"><a name="introduction">Introduction</a></div>
75<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]76
77<div class="doc_text">
78
79<p>This document is the central repository for all information pertaining to
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]80debug information in LLVM. It describes the <a href="#format">actual format
81that the LLVM debug information</a> takes, which is useful for those interested
82in creating front-ends or dealing directly with the information. Further, this
83document provides specifc examples of what debug information for C/C++.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]84
85</div>
86
87<!-- ======================================================================= -->
88<div class="doc_subsection">
89 <a name="phil">Philosophy behind LLVM debugging information</a>
90</div>
91
92<div class="doc_text">
93
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]94<p>The idea of the LLVM debugging information is to capture how the important
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]95pieces of the source-language's Abstract Syntax Tree map onto LLVM code.
96Several design aspects have shaped the solution that appears here. The
97important ones are:</p>
98
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]99<ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]100<li>Debugging information should have very little impact on the rest of the
101compiler. No transformations, analyses, or code generators should need to be
102modified because of debugging information.</li>
103
104<li>LLVM optimizations should interact in <a href="#debugopt">well-defined and
105easily described ways</a> with the debugging information.</li>
106
107<li>Because LLVM is designed to support arbitrary programming languages,
108LLVM-to-LLVM tools should not need to know anything about the semantics of the
109source-level-language.</li>
110
111<li>Source-level languages are often <b>widely</b> different from one another.
112LLVM should not put any restrictions of the flavor of the source-language, and
113the debugging information should work with any language.</li>
114
115<li>With code generator support, it should be possible to use an LLVM compiler
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]116to compile a program to native machine code and standard debugging formats.
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]117This allows compatibility with traditional machine-code level debuggers, like
118GDB or DBX.</li>
119
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]120</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]121
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]122<p>The approach used by the LLVM implementation is to use a small set of <a
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]123href="#format_common_intrinsics">intrinsic functions</a> to define a mapping
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]124between LLVM program objects and the source-level objects. The description of
125the source-level program is maintained in LLVM global variables in an <a
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]126href="#ccxx_frontend">implementation-defined format</a> (the C/C++ front-end
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]127currently uses working draft 7 of the <a
128href="http://www.eagercon.com/dwarf/dwarf3std.htm">Dwarf 3 standard</a>).</p>
129
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]130<p>When a program is being debugged, a debugger interacts with the user and
131turns the stored debug information into source-language specific information.
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]132As such, a debugger must be aware of the source-language, and is thus tied to
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]133a specific language of family of languages.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]134
135</div>
136
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]137<!-- ======================================================================= -->
138<div class="doc_subsection">
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]139 <a name="consumers">Debug information consumers</a>
140</div>
141
142<div class="doc_text">
143<p>The role of debug information is to provide meta information normally
144stripped away during the compilation process. This meta information provides an
145llvm user a relationship between generated code and the original program source
146code.</p>
147
148<p>Currently, debug information is consumed by the DwarfWriter to produce dwarf
149information used by the gdb debugger. Other targets could use the same
150information to produce stabs or other debug forms.</p>
151
152<p>It would also be reasonable to use debug information to feed profiling tools
153for analysis of generated code, or, tools for reconstructing the original source
154from generated code.</p>
155
156<p>TODO - expound a bit more.</p>
157
158</div>
159
160<!-- ======================================================================= -->
161<div class="doc_subsection">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]162 <a name="debugopt">Debugging optimized code</a>
163</div>
164
165<div class="doc_text">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]166
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]167<p>An extremely high priority of LLVM debugging information is to make it
168interact well with optimizations and analysis. In particular, the LLVM debug
169information provides the following guarantees:</p>
170
171<ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]172
173<li>LLVM debug information <b>always provides information to accurately read the
174source-level state of the program</b>, regardless of which LLVM optimizations
175have been run, and without any modification to the optimizations themselves.
176However, some optimizations may impact the ability to modify the current state
177of the program with a debugger, such as setting program variables, or calling
178function that have been deleted.</li>
179
180<li>LLVM optimizations gracefully interact with debugging information. If they
181are not aware of debug information, they are automatically disabled as necessary
182in the cases that would invalidate the debug info. This retains the LLVM
183features making it easy to write new transformations.</li>
184
185<li>As desired, LLVM optimizations can be upgraded to be aware of the LLVM
186debugging information, allowing them to update the debugging information as they
187perform aggressive optimizations. This means that, with effort, the LLVM
188optimizers could optimize debug code just as well as non-debug code.</li>
189
190<li>LLVM debug information does not prevent many important optimizations from
191happening (for example inlining, basic block reordering/merging/cleanup, tail
192duplication, etc), further reducing the amount of the compiler that eventually
193is "aware" of debugging information.</li>
194
195<li>LLVM debug information is automatically optimized along with the rest of the
196program, using existing facilities. For example, duplicate information is
197automatically merged by the linker, and unused information is automatically
198removed.</li>
199
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]200</ul>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]201
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]202<p>Basically, the debug information allows you to compile a program with
203"<tt>-O0 -g</tt>" and get full debug information, allowing you to arbitrarily
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]204modify the program as it executes from a debugger. Compiling a program with
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]205"<tt>-O3 -g</tt>" gives you full debug information that is always available and
206accurate for reading (e.g., you get accurate stack traces despite tail call
207elimination and inlining), but you might lose the ability to modify the program
208and call functions where were optimized out of the program, or inlined away
209completely.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]210
211</div>
212
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]213<!-- *********************************************************************** -->
214<div class="doc_section">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]215 <a name="format">Debugging information format</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]216</div>
217<!-- *********************************************************************** -->
218
219<div class="doc_text">
220
221<p>LLVM debugging information has been carefully designed to make it possible
222for the optimizer to optimize the program and debugging information without
223necessarily having to know anything about debugging information. In particular,
224the global constant merging pass automatically eliminates duplicated debugging
225information (often caused by header files), the global dead code elimination
226pass automatically deletes debugging information for a function if it decides to
227delete the function, and the linker eliminates debug information when it merges
228<tt>linkonce</tt> functions.</p>
229
230<p>To do this, most of the debugging information (descriptors for types,
231variables, functions, source files, etc) is inserted by the language front-end
232in the form of LLVM global variables. These LLVM global variables are no
233different from any other global variables, except that they have a web of LLVM
234intrinsic functions that point to them. If the last references to a particular
235piece of debugging information are deleted (for example, by the
236<tt>-globaldce</tt> pass), the extraneous debug information will automatically
237become dead and be removed by the optimizer.</p>
238
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]239<p>Debug information is designed to be agnostic about the target debugger and
240debugging information representation (e.g. DWARF/Stabs/etc). It uses a generic
241machine debug information pass to decode the information that represents
242variables, types, functions, namespaces, etc: this allows for arbitrary
243source-language semantics and type-systems to be used, as long as there is a
244module written for the target debugger to interpret the information. In
245addition, debug global variables are declared in the <tt>"llvm.metadata"</tt>
246section. All values declared in this section are stripped away after target
247debug information is constructed and before the program object is emitted.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]248
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]249<p>To provide basic functionality, the LLVM debugger does have to make some
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]250assumptions about the source-level language being debugged, though it keeps
251these to a minimum. The only common features that the LLVM debugger assumes
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]252exist are <a href="#format_compile_units">source files</a>, and <a
253href="#format_global_variables">program objects</a>. These abstract objects are
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]254used by a debugger to form stack traces, show information about local
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]255variables, etc.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]256
257<p>This section of the documentation first describes the representation aspects
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]258common to any source-language. The <a href="#ccxx_frontend">next section</a>
259describes the data layout conventions used by the C and C++ front-ends.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]260
261</div>
262
263<!-- ======================================================================= -->
264<div class="doc_subsection">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]265 <a name="debug_info_descriptors">Debug information descriptors</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]266</div>
267
268<div class="doc_text">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]269<p>In consideration of the complexity and volume of debug information, LLVM
270provides a specification for well formed debug global variables. The constant
271value of each of these globals is one of a limited set of structures, known as
272debug descriptors.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]273
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]274<p>Consumers of LLVM debug information expect the descriptors for program
275objects to start in a canonical format, but the descriptors can include
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]276additional information appended at the end that is source-language specific. All
277LLVM debugging information is versioned, allowing backwards compatibility in the
278case that the core structures need to change in some way. Also, all debugging
279information objects start with a tag to indicate what type of object it is. The
280source-language is allowed to define its own objects, by using unreserved tag
281numbers. We recommend using with tags in the range 0x1000 thru 0x2000 (there is
282a defined enum DW_TAG_user_base = 0x1000.)</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]283
284<p>The fields of debug descriptors used internally by LLVM (MachineDebugInfo)
285are restricted to only the simple data types <tt>int</tt>, <tt>uint</tt>,
286<tt>bool</tt>, <tt>float</tt>, <tt>double</tt>, <tt>sbyte*</tt> and <tt> { }*
287</tt>. References to arbitrary values are handled using a <tt> { }* </tt> and a
288cast to <tt> { }* </tt> expression; typically references to other field
289descriptors, arrays of descriptors or global variables.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]290
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]291<pre>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]292 %llvm.dbg.object.type = type {
293 uint, ;; A tag
294 ...
295 }
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]296</pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]297
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]298<p>The first field of a descriptor is always an <tt>uint</tt> containing a tag
299value identifying the content of the descriptor. The remaining fields are
300specific to the descriptor. The values of tags are loosely bound to the tag
301values of Dwarf information entries. However, that does not restrict the use of
302the information supplied to Dwarf targets.</p>
303
304<p>The details of the various descriptors follow.</p>
305
306</div>
307
308<!-- ======================================================================= -->
309<div class="doc_subsubsection">
310 <a name="format_anchors">Anchor descriptors</a>
311</div>
312
313<div class="doc_text">
314
315<pre>
316 %<a href="#format_anchors">llvm.dbg.anchor.type</a> = type {
317 uint, ;; Tag = 0
318 uint ;; Tag of descriptors grouped by the anchor
319 }
320</pre>
321
322<p>One important aspect of the LLVM debug representation is that it allows the
323LLVM debugger to efficiently index all of the global objects without having the
324scan the program. To do this, all of the global objects use "anchor"
325descriptors with designated names. All of the global objects of a particular
326type (e.g., compile units) contain a pointer to the anchor. This pointer allows
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]327a debugger to use def-use chains to find all global objects of that type.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]328
329<p>The following names are recognized as anchors by LLVM:</p>
330
331<pre>
332 %<a href="#format_compile_units">llvm.dbg.compile_units</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { uint 0, uint 17 } ;; DW_TAG_compile_unit
333 %<a href="#format_global_variables">llvm.dbg.global_variables</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { uint 0, uint 52 } ;; DW_TAG_variable
334 %<a href="#format_subprograms">llvm.dbg.subprograms</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { uint 0, uint 46 } ;; DW_TAG_subprogram
335</pre>
336
337<p>Using anchors in this way (where the compile unit descriptor points to the
338anchors, as opposed to having a list of compile unit descriptors) allows for the
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]339standard dead global elimination and merging passes to automatically remove
340unused debugging information. If the globals were kept track of through lists,
341there would always be an object pointing to the descriptors, thus would never be
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]342deleted.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]343
344</div>
345
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]346<!-- ======================================================================= -->
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]347<div class="doc_subsubsection">
348 <a name="format_compile_units">Compile unit descriptors</a>
349</div>
350
351<div class="doc_text">
352
353<pre>
354 %<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> = type {
355 uint, ;; Tag = 17 (DW_TAG_compile_unit)
356 { }*, ;; Compile unit anchor = cast = (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_units</a> to { }*)
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]357 uint, ;; LLVM debug version number = 3
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]358 uint, ;; Dwarf language identifier (ex. DW_LANG_C89)
359 sbyte*, ;; Source file name
360 sbyte*, ;; Source file directory (includes trailing slash)
361 sbyte* ;; Producer (ex. "4.0.1 LLVM (LLVM research group)")
362 }
363</pre>
364
365<p>These descriptors contain the version number for the debug info (currently
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]3663), a source language ID for the file (we use the Dwarf 3.0 ID numbers, such as
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]367<tt>DW_LANG_C89</tt>, <tt>DW_LANG_C_plus_plus</tt>, <tt>DW_LANG_Cobol74</tt>,
368etc), three strings describing the filename, working directory of the compiler,
369and an identifier string for the compiler that produced it.</p>
370
371<p> Compile unit descriptors provide the root context for objects declared in a
372specific source file. Global variables and top level functions would be defined
373using this context. Compile unit descriptors also provide context for source
374line correspondence.</p>
375
376</div>
377
378<!-- ======================================================================= -->
379<div class="doc_subsubsection">
380 <a name="format_global_variables">Global variable descriptors</a>
381</div>
382
383<div class="doc_text">
384
385<pre>
386 %<a href="#format_global_variables">llvm.dbg.global_variable.type</a> = type {
387 uint, ;; Tag = 52 (DW_TAG_variable)
388 { }*, ;; Global variable anchor = cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_global_variables">llvm.dbg.global_variables</a> to { }*),
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]389 { }*, ;; Reference to context descriptor
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]390 sbyte*, ;; Name
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]391 { }*, ;; Reference to compile unit where defined
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]392 uint, ;; Line number where defined
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]393 { }*, ;; Reference to type descriptor
394 bool, ;; True if the global is local to compile unit (static)
395 bool, ;; True if the global is defined in the compile unit (not extern)
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]396 { }* ;; Reference to the global variable
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]397 }
398</pre>
399
400<p>These descriptors provide debug information about globals variables. The
401provide details such as name, type and where the variable is defined.</p>
402
403</div>
404
405<!-- ======================================================================= -->
406<div class="doc_subsubsection">
407 <a name="format_subprograms">Subprogram descriptors</a>
408</div>
409
410<div class="doc_text">
411
412<pre>
413 %<a href="#format_subprograms">llvm.dbg.subprogram.type</a> = type {
414 uint, ;; Tag = 46 (DW_TAG_subprogram)
415 { }*, ;; Subprogram anchor = cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_subprograms">llvm.dbg.subprograms</a> to { }*),
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]416 { }*, ;; Reference to context descriptor
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]417 sbyte*, ;; Name
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]418 { }*, ;; Reference to compile unit where defined
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]419 uint, ;; Line number where defined
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]420 { }*, ;; Reference to type descriptor
421 bool, ;; True if the global is local to compile unit (static)
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]422 bool ;; True if the global is defined in the compile unit (not extern)
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]423 }
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]424</pre>
425
426<p>These descriptors provide debug information about functions, methods and
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]427subprograms. They provide details such as name, return types and the source
428location where the subprogram is defined.</p>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]429
430</div>
431<!-- ======================================================================= -->
432<div class="doc_subsubsection">
433 <a name="format_blocks">Block descriptors</a>
434</div>
435
436<div class="doc_text">
437
438<pre>
439 %<a href="#format_blocks">llvm.dbg.block</a> = type {
440 uint, ;; Tag = 13 (DW_TAG_lexical_block)
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]441 { }* ;; Reference to context descriptor
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]442 }
443</pre>
444
445<p>These descriptors provide debug information about nested blocks within a
446subprogram. The array of member descriptors is used to define local variables
447and deeper nested blocks.</p>
448
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]449</div>
450
451<!-- ======================================================================= -->
452<div class="doc_subsubsection">
453 <a name="format_basic_type">Basic type descriptors</a>
454</div>
455
456<div class="doc_text">
457
458<pre>
459 %<a href="#format_basic_type">llvm.dbg.basictype.type</a> = type {
460 uint, ;; Tag = 36 (DW_TAG_base_type)
461 { }*, ;; Reference to context (typically a compile unit)
462 sbyte*, ;; Name (may be "" for anonymous types)
463 { }*, ;; Reference to compile unit where defined (may be NULL)
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]464 uint, ;; Line number where defined (may be 0)
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]465 uint, ;; Size in bits
466 uint, ;; Alignment in bits
467 uint, ;; Offset in bits
468 uint ;; Dwarf type encoding
469 }
470</pre>
471
472<p>These descriptors define primitive types used in the code. Example int, bool
473and float. The context provides the scope of the type, which is usually the top
474level. Since basic types are not usually user defined the compile unit and line
475number can be left as NULL and 0. The size, alignment and offset are expressed
476in bits and can be 64 bit values. The alignment is used to round the offset
477when embedded in a <a href="#format_composite_type">composite type</a>
478(example to keep float doubles on 64 bit boundaries.) The offset is the bit
479offset if embedded in a <a href="#format_composite_type">composite
480type</a>.</p>
481
482<p>The type encoding provides the details of the type. The values are typically
483one of the following;</p>
484
485<pre>
486 DW_ATE_address = 1
487 DW_ATE_boolean = 2
488 DW_ATE_float = 4
489 DW_ATE_signed = 5
490 DW_ATE_signed_char = 6
491 DW_ATE_unsigned = 7
492 DW_ATE_unsigned_char = 8
493</pre>
494
495</div>
496
497<!-- ======================================================================= -->
498<div class="doc_subsubsection">
499 <a name="format_derived_type">Derived type descriptors</a>
500</div>
501
502<div class="doc_text">
503
504<pre>
505 %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> = type {
506 uint, ;; Tag (see below)
507 { }*, ;; Reference to context
508 sbyte*, ;; Name (may be "" for anonymous types)
509 { }*, ;; Reference to compile unit where defined (may be NULL)
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]510 uint, ;; Line number where defined (may be 0)
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]511 uint, ;; Size in bits
512 uint, ;; Alignment in bits
513 uint, ;; Offset in bits
514 { }* ;; Reference to type derived from
515 }
516</pre>
517
518<p>These descriptors are used to define types derived from other types. The
519value of the tag varies depending on the meaning. The following are possible
520tag values;</p>
521
522<pre>
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]523 DW_TAG_formal_parameter = 5
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]524 DW_TAG_member = 13
525 DW_TAG_pointer_type = 15
526 DW_TAG_reference_type = 16
527 DW_TAG_typedef = 22
528 DW_TAG_const_type = 38
529 DW_TAG_volatile_type = 53
530 DW_TAG_restrict_type = 55
531</pre>
532
533<p> <tt>DW_TAG_member</tt> is used to define a member of a <a
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]534href="#format_composite_type">composite type</a> or <a
535href="#format_subprograms">subprogram</a>. The type of the member is the <a
536href="#format_derived_type">derived type</a>. <tt>DW_TAG_formal_parameter</tt>
537is used to define a member which is a formal argument of a subprogram.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]538
539<p><tt>DW_TAG_typedef</tt> is used to
540provide a name for the derived type.</p>
541
542<p><tt>DW_TAG_pointer_type</tt>,
543<tt>DW_TAG_reference_type</tt>, <tt>DW_TAG_const_type</tt>,
544<tt>DW_TAG_volatile_type</tt> and <tt>DW_TAG_restrict_type</tt> are used to
545qualify the <a href="#format_derived_type">derived type</a>. </p>
546
547<p><a href="#format_derived_type">Derived type</a> location can be determined
548from the compile unit and line number. The size, alignment and offset are
549expressed in bits and can be 64 bit values. The alignment is used to round the
550offset when embedded in a <a href="#format_composite_type">composite type</a>
551(example to keep float doubles on 64 bit boundaries.) The offset is the bit
552offset if embedded in a <a href="#format_composite_type">composite
553type</a>.</p>
554
555<p>Note that the <tt>void *</tt> type is expressed as a
556<tt>llvm.dbg.derivedtype.type</tt> with tag of <tt>DW_TAG_pointer_type</tt> and
557NULL derived type.</p>
558
559</div>
560
561<!-- ======================================================================= -->
562<div class="doc_subsubsection">
563 <a name="format_composite_type">Composite type descriptors</a>
564</div>
565
566<div class="doc_text">
567
568<pre>
569 %<a href="#format_composite_type">llvm.dbg.compositetype.type</a> = type {
570 uint, ;; Tag (see below)
571 { }*, ;; Reference to context
572 sbyte*, ;; Name (may be "" for anonymous types)
573 { }*, ;; Reference to compile unit where defined (may be NULL)
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]574 uint, ;; Line number where defined (may be 0)
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]575 uint, ;; Size in bits
576 uint, ;; Alignment in bits
577 uint, ;; Offset in bits
578 { }* ;; Reference to array of member descriptors
579 }
580</pre>
581
582<p>These descriptors are used to define types that are composed of 0 or more
583elements. The value of the tag varies depending on the meaning. The following
584are possible tag values;</p>
585
586<pre>
587 DW_TAG_array_type = 1
588 DW_TAG_enumeration_type = 4
589 DW_TAG_structure_type = 19
590 DW_TAG_union_type = 23
591</pre>
592
593<p>The members of array types (tag = <tt>DW_TAG_array_type</tt>) are <a
594href="#format_subrange">subrange descriptors</a>, each representing the range of
595subscripts at that level of indexing.</p>
596
597<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are
598<a href="#format_enumeration">enumerator descriptors</a>, each representing the
599definition of enumeration value
600for the set.</p>
601
602<p>The members of structure (tag = <tt>DW_TAG_structure_type</tt>) or union (tag
603= <tt>DW_TAG_union_type</tt>) types are any one of the <a
604href="#format_basic_type">basic</a>, <a href="#format_derived_type">derived</a>
605or <a href="#format_composite_type">composite</a> type descriptors, each
606representing a field member of the structure or union.</p>
607
608<p><a href="#format_composite_type">Composite type</a> location can be
609determined from the compile unit and line number. The size, alignment and
610offset are expressed in bits and can be 64 bit values. The alignment is used to
611round the offset when embedded in a <a href="#format_composite_type">composite
612type</a> (as an example, to keep float doubles on 64 bit boundaries.) The offset
613is the bit offset if embedded in a <a href="#format_composite_type">composite
614type</a>.</p>
615
616</div>
617
618<!-- ======================================================================= -->
619<div class="doc_subsubsection">
620 <a name="format_subrange">Subrange descriptors</a>
621</div>
622
623<div class="doc_text">
624
625<pre>
626 %<a href="#format_subrange">llvm.dbg.subrange.type</a> = type {
627 uint, ;; Tag = 33 (DW_TAG_subrange_type)
628 uint, ;; Low value
629 uint ;; High value
630 }
631</pre>
632
633<p>These descriptors are used to define ranges of array subscripts for an array
634<a href="#format_composite_type">composite type</a>. The low value defines the
635lower bounds typically zero for C/C++. The high value is the upper bounds.
636Values are 64 bit. High - low + 1 is the size of the array. If
637low == high the array will be unbounded.</p>
638
639</div>
640
641<!-- ======================================================================= -->
642<div class="doc_subsubsection">
643 <a name="format_enumeration">Enumerator descriptors</a>
644</div>
645
646<div class="doc_text">
647
648<pre>
649 %<a href="#format_enumeration">llvm.dbg.enumerator.type</a> = type {
650 uint, ;; Tag = 40 (DW_TAG_enumerator)
651 sbyte*, ;; Name
652 uint ;; Value
653 }
654</pre>
655
656<p>These descriptors are used to define members of an enumeration <a
657href="#format_composite_type">composite type</a>, it associates the name to the
658value.</p>
659
660</div>
661
662<!-- ======================================================================= -->
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]663<div class="doc_subsubsection">
664 <a name="format_variables">Local variables</a>
665</div>
666
667<div class="doc_text">
668<pre>
669 %<a href="#format_variables">llvm.dbg.variable.type</a> = type {
670 uint, ;; Tag (see below)
671 { }*, ;; Context
672 sbyte*, ;; Name
673 { }*, ;; Reference to compile unit where defined
674 uint, ;; Line number where defined
675 { }* ;; Type descriptor
676 }
677</pre>
678
679<p>These descriptors are used to define variables local to a sub program. The
680value of the tag depends on the usage of the variable;</p>
681
682<pre>
683 DW_TAG_auto_variable = 256
684 DW_TAG_arg_variable = 257
685 DW_TAG_return_variable = 258
686</pre>
687
688<p>An auto variable is any variable declared in the body of the function. An
689argument variable is any variable that appears as a formal argument to the
690function. A return variable is used to track the result of a function and has
691no source correspondent.</p>
692
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame^]693<p>The context is either the subprogram or block where the variable is defined.
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]694Name the source variable name. Compile unit and line indicate where the
695variable was defined. Type descriptor defines the declared type of the
696variable.</p>
697
698</div>
699
700<!-- ======================================================================= -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]701<div class="doc_subsection">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]702 <a name="format_common_intrinsics">Debugger intrinsic functions</a>
703</div>
704
705<div class="doc_text">
706
707<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to
708provide debug information at various points in generated code.</p>
709
710</div>
711
712<!-- ======================================================================= -->
713<div class="doc_subsubsection">
714 <a name="format_common_stoppoint">llvm.dbg.stoppoint</a>
715</div>
716
717<div class="doc_text">
718<pre>
Jim Laskey108a6382006-03-23 17:58:46 +0000[diff] [blame]719 void %<a href="#format_common_stoppoint">llvm.dbg.stoppoint</a>( uint, uint, { }* )
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]720</pre>
721
722<p>This intrinsic is used to provide correspondence between the source file and
723the generated code. The first argument is the line number (base 1), second
724argument si the column number (0 if unknown) and the third argument the source
Jim Laskey108a6382006-03-23 17:58:46 +0000[diff] [blame]725<tt>%<a href="#format_compile_units">llvm.dbg.compile_unit</a>*</tt> cast to a
726<tt>{ }*</tt>. Code following a call to this intrinsic will have been defined
727in close proximity of the line, column and file. This information holds until
728the next call to <tt>%<a
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]729href="#format_common_stoppoint">lvm.dbg.stoppoint</a></tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]730
731</div>
732
733<!-- ======================================================================= -->
734<div class="doc_subsubsection">
735 <a name="format_common_func_start">llvm.dbg.func.start</a>
736</div>
737
738<div class="doc_text">
739<pre>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]740 void %<a href="#format_common_func_start">llvm.dbg.func.start</a>( { }* )
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]741</pre>
742
743<p>This intrinsic is used to link the debug information in <tt>%<a
744href="#format_subprograms">llvm.dbg.subprogram</a></tt> to the function. It also
745defines the beginning of the function's declarative region (scope.) The
746intrinsic should be called early in the function after the all the alloca
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]747instructions. It should be paired off with a closing <tt>%<a
748href="#format_common_region_end">llvm.dbg.region.end</a></tt>. The function's
749single argument is the <tt>%<a
750href="#format_subprograms">llvm.dbg.subprogram.type</a></tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]751
752</div>
753
754<!-- ======================================================================= -->
755<div class="doc_subsubsection">
756 <a name="format_common_region_start">llvm.dbg.region.start</a>
757</div>
758
759<div class="doc_text">
760<pre>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]761 void %<a href="#format_common_region_start">llvm.dbg.region.start</a>( { }* )
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]762</pre>
763
764<p>This intrinsic is used to define the beginning of a declarative scope (ex.
765block) for local language elements. It should be paired off with a closing
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]766<tt>%<a href="#format_common_region_end">llvm.dbg.region.end</a></tt>. The
767function's single argument is the <tt>%<a
768href="#format_blocks">llvm.dbg.block</a></tt> which is starting.</p>
769
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]770
771</div>
772
773<!-- ======================================================================= -->
774<div class="doc_subsubsection">
775 <a name="format_common_region_end">llvm.dbg.region.end</a>
776</div>
777
778<div class="doc_text">
779<pre>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]780 void %<a href="#format_common_region_end">llvm.dbg.region.end</a>( { }* )
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]781</pre>
782
783<p>This intrinsic is used to define the end of a declarative scope (ex. block)
784for local language elements. It should be paired off with an opening <tt>%<a
785href="#format_common_region_start">llvm.dbg.region.start</a></tt> or <tt>%<a
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]786href="#format_common_func_start">llvm.dbg.func.start</a></tt>. The function's
787single argument is either the <tt>%<a
788href="#format_blocks">llvm.dbg.block</a></tt> or the <tt>%<a
789href="#format_subprograms">llvm.dbg.subprogram.type</a></tt> which is
790ending.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]791
792</div>
793
794<!-- ======================================================================= -->
795<div class="doc_subsubsection">
796 <a name="format_common_declare">llvm.dbg.declare</a>
797</div>
798
799<div class="doc_text">
800<pre>
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]801 void %<a href="#format_common_declare">llvm.dbg.declare</a>( { } *, { }* )
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]802</pre>
803
Jim Laskey2d395d92006-03-24 09:20:27 +0000[diff] [blame^]804<p>This intrinsic provides information about a local element (ex. variable.) The
805first argument is the alloca for the variable, cast to a <tt>{ }*</tt>. The
806second argument is the <tt>%<a
807href="#format_variables">llvm.dbg.variable</a></tt> containing the description
808of the variable, also cast to a <tt>{ }*</tt>.</p>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]809
810</div>
811
812<!-- ======================================================================= -->
813<div class="doc_subsection">
814 <a name="format_common_stoppoints">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]815 Representing stopping points in the source program
816 </a>
817</div>
818
819<div class="doc_text">
820
821<p>LLVM debugger "stop points" are a key part of the debugging representation
822that allows the LLVM to maintain simple semantics for <a
823href="#debugopt">debugging optimized code</a>. The basic idea is that the
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]824front-end inserts calls to the <a
825href="#format_common_stoppoint">%<tt>llvm.dbg.stoppoint</tt></a> intrinsic
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]826function at every point in the program where a debugger should be able to
827inspect the program (these correspond to places a debugger stops when you
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]828"<tt>step</tt>" through it). The front-end can choose to place these as
829fine-grained as it would like (for example, before every subexpression
830evaluated), but it is recommended to only put them after every source statement
831that includes executable code.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]832
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]833<p>Using calls to this intrinsic function to demark legal points for the
834debugger to inspect the program automatically disables any optimizations that
835could potentially confuse debugging information. To non-debug-information-aware
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]836transformations, these calls simply look like calls to an external function,
837which they must assume to do anything (including reading or writing to any part
838of reachable memory). On the other hand, it does not impact many optimizations,
839such as code motion of non-trapping instructions, nor does it impact
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]840optimization of subexpressions, code duplication transformations, or basic-block
841reordering transformations.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]842
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]843</div>
844
845
846<!-- ======================================================================= -->
847<div class="doc_subsection">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]848 <a name="format_common_lifetime">Object lifetimes and scoping</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]849</div>
850
851<div class="doc_text">
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]852<p>In many languages, the local variables in functions can have their lifetime
853or scope limited to a subset of a function. In the C family of languages, for
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]854example, variables are only live (readable and writable) within the source block
855that they are defined in. In functional languages, values are only readable
856after they have been defined. Though this is a very obvious concept, it is also
857non-trivial to model in LLVM, because it has no notion of scoping in this sense,
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]858and does not want to be tied to a language's scoping rules.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]859
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]860<p>In order to handle this, the LLVM debug format uses the notion of "regions"
861of a function, delineated by calls to intrinsic functions. These intrinsic
862functions define new regions of the program and indicate when the region
863lifetime expires. Consider the following C fragment, for example:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]864
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]865<pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]8661. void foo() {
8672. int X = ...;
8683. int Y = ...;
8694. {
8705. int Z = ...;
8716. ...
8727. }
8738. ...
8749. }
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]875</pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]876
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]877<p>Compiled to LLVM, this function would be represented like this:</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]878
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]879<pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]880void %foo() {
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]881entry:
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]882 %X = alloca int
883 %Y = alloca int
884 %Z = alloca int
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]885
886 ...
887
888 call void %<a href="#format_common_func_start">llvm.dbg.func.start</a>( %<a href="#format_subprograms">llvm.dbg.subprogram.type</a>* %llvm.dbg.subprogram )
889
890 call void %<a href="#format_common_stoppoint">llvm.dbg.stoppoint</a>( uint 2, uint 2, %<a href="#format_compile_units">llvm.dbg.compile_unit</a>* %llvm.dbg.compile_unit )
891
892 call void %<a href="#format_common_declare">llvm.dbg.declare</a>({}* %X, ...)
893 call void %<a href="#format_common_declare">llvm.dbg.declare</a>({}* %Y, ...)
894
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]895 <i>;; Evaluate expression on line 2, assigning to X.</i>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]896
897 call void %<a href="#format_common_stoppoint">llvm.dbg.stoppoint</a>( uint 3, uint 2, %<a href="#format_compile_units">llvm.dbg.compile_unit</a>* %llvm.dbg.compile_unit )
898
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]899 <i>;; Evaluate expression on line 3, assigning to Y.</i>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]900
901 call void %<a href="#format_common_stoppoint">llvm.region.start</a>()
902 call void %<a href="#format_common_stoppoint">llvm.dbg.stoppoint</a>( uint 5, uint 4, %<a href="#format_compile_units">llvm.dbg.compile_unit</a>* %llvm.dbg.compile_unit )
903 call void %<a href="#format_common_declare">llvm.dbg.declare</a>({}* %X, ...)
904
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]905 <i>;; Evaluate expression on line 5, assigning to Z.</i>
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]906
907 call void %<a href="#format_common_stoppoint">llvm.dbg.stoppoint</a>( uint 7, uint 2, %<a href="#format_compile_units">llvm.dbg.compile_unit</a>* %llvm.dbg.compile_unit )
908 call void %<a href="#format_common_region_end">llvm.region.end</a>()
909
910 call void %<a href="#format_common_stoppoint">llvm.dbg.stoppoint</a>( uint 9, uint 2, %<a href="#format_compile_units">llvm.dbg.compile_unit</a>* %llvm.dbg.compile_unit )
911
912 call void %<a href="#format_common_region_end">llvm.region.end</a>()
913
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]914 ret void
915}
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]916</pre>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]917
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]918<p>This example illustrates a few important details about the LLVM debugging
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]919information. In particular, it shows how the various intrinsics are applied
920together to allow a debugger to analyze the relationship between statements,
921variable definitions, and the code used to implement the function.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]922
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]923<p>The first intrinsic <tt>%<a
924href="#format_common_func_start">llvm.dbg.func.start</a></tt> provides
925a link with the <a href="#format_subprograms">subprogram descriptor</a>
926containing the details of this function. This call also defines the beginning
927of the function region, bounded by the <tt>%<a
928href="#format_common_region_end">llvm.region.end</a></tt> at the end of
929the function. This region is used to bracket the lifetime of variables declared
930within. For a function, this outer region defines a new stack frame whose
931lifetime ends when the region is ended.</p>
932
933<p>It is possible to define inner regions for short term variables by using the
934%<a href="#format_common_stoppoint"><tt>llvm.region.start</tt></a> and <a
935href="#format_common_region_end"><tt>%llvm.region.end</tt></a> to bound a
936region. The inner region in this example would be for the block containing the
937declaration of Z.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]938
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]939<p>Using regions to represent the boundaries of source-level functions allow
940LLVM interprocedural optimizations to arbitrarily modify LLVM functions without
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]941having to worry about breaking mapping information between the LLVM code and the
942and source-level program. In particular, the inliner requires no modification
943to support inlining with debugging information: there is no explicit correlation
944drawn between LLVM functions and their source-level counterparts (note however,
945that if the inliner inlines all instances of a non-strong-linkage function into
946its caller that it will not be possible for the user to manually invoke the
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]947inlined function from a debugger).</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]948
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]949<p>Once the function has been defined, the <a
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]950href="#format_common_stoppoint"><tt>stopping point</tt></a> corresponding to
951line #2 (column #2) of the function is encountered. At this point in the
952function, <b>no</b> local variables are live. As lines 2 and 3 of the example
953are executed, their variable definitions are introduced into the program using
954%<a href="#format_common_declare"><tt>llvm.dbg.declare</tt></a>, without the
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]955need to specify a new region. These variables do not require new regions to be
956introduced because they go out of scope at the same point in the program: line
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]9579.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]958
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]959<p>In contrast, the <tt>Z</tt> variable goes out of scope at a different time,
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]960on line 7. For this reason, it is defined within the inner region, which kills
961the availability of <tt>Z</tt> before the code for line 8 is executed. In this
962way, regions can support arbitrary source-language scoping rules, as long as
963they can only be nested (ie, one scope cannot partially overlap with a part of
964another scope).</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]965
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]966<p>It is worth noting that this scoping mechanism is used to control scoping of
967all declarations, not just variable declarations. For example, the scope of a
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]968C++ using declaration is controlled with this couldchange how name lookup is
969performed.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]970
971</div>
972
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]973
974
975<!-- *********************************************************************** -->
976<div class="doc_section">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]977 <a name="ccxx_frontend">C/C++ front-end specific debug information</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]978</div>
Misha Brukman94218a72004-12-09 20:27:37 +0000[diff] [blame]979<!-- *********************************************************************** -->
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]980
981<div class="doc_text">
982
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]983<p>The C and C++ front-ends represent information about the program in a format
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]984that is effectively identical to <a
985href="http://www.eagercon.com/dwarf/dwarf3std.htm">Dwarf 3.0</a> in terms of
986information content. This allows code generators to trivially support native
987debuggers by generating standard dwarf information, and contains enough
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]988information for non-dwarf targets to translate it as needed.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]989
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]990<p>This section describes the forms used to represent C and C++ programs. Other
991languages could pattern themselves after this (which itself is tuned to
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]992representing programs in the same way that Dwarf 3 does), or they could choose
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]993to provide completely different forms if they don't fit into the Dwarf model.
994As support for debugging information gets added to the various LLVM
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]995source-language front-ends, the information used should be documented here.</p>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]996
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]997<p>The following sections provide examples of various C/C++ constructs and the
998debug information that would best describe those constructs.</p>
999
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1000</div>
1001
1002<!-- ======================================================================= -->
1003<div class="doc_subsection">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1004 <a name="ccxx_compile_units">C/C++ source file information</a>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1005</div>
1006
1007<div class="doc_text">
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1008
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1009<p>Given the source files "MySource.cpp" and "MyHeader.h" located in the
1010directory "/Users/mine/sources", the following code;</p>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1011
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1012<pre>
1013#include "MyHeader.h"
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1014
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1015int main(int argc, char *argv[]) {
1016 return 0;
1017}
1018</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1019
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1020<p>a C/C++ front-end would generate the following descriptors;</p>
1021
1022<pre>
1023...
1024;;
1025;; Define types used. In this case we need one for compile unit anchors and one
1026;; for compile units.
1027;;
1028%<a href="#format_anchors">llvm.dbg.anchor.type</a> = type { uint, uint }
1029%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> = type { uint, { }*, uint, uint, sbyte*, sbyte*, sbyte* }
1030...
1031;;
1032;; Define the anchor for compile units. Note that the second field of the
1033;; anchor is 17, which is the same as the tag for compile units
1034;; (17 = DW_TAG_compile_unit.)
1035;;
1036%<a href="#format_compile_units">llvm.dbg.compile_units</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { uint 0, uint 17 }, section "llvm.metadata"
1037
1038;;
1039;; Define the compile unit for the source file "/Users/mine/sources/MySource.cpp".
1040;;
1041%<a href="#format_compile_units">llvm.dbg.compile_unit1</a> = internal constant %<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> {
1042 uint 17,
1043 { }* cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_units</a> to { }*),
1044 uint 1,
1045 uint 1,
1046 sbyte* getelementptr ([13 x sbyte]* %str1, int 0, int 0),
1047 sbyte* getelementptr ([21 x sbyte]* %str2, int 0, int 0),
1048 sbyte* getelementptr ([33 x sbyte]* %str3, int 0, int 0) }, section "llvm.metadata"
1049
1050;;
1051;; Define the compile unit for the header file "/Users/mine/sources/MyHeader.h".
1052;;
1053%<a href="#format_compile_units">llvm.dbg.compile_unit2</a> = internal constant %<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> {
1054 uint 17,
1055 { }* cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_units</a> to { }*),
1056 uint 1,
1057 uint 1,
1058 sbyte* getelementptr ([11 x sbyte]* %str4, int 0, int 0),
1059 sbyte* getelementptr ([21 x sbyte]* %str2, int 0, int 0),
1060 sbyte* getelementptr ([33 x sbyte]* %str3, int 0, int 0) }, section "llvm.metadata"
1061
1062;;
1063;; Define each of the strings used in the compile units.
1064;;
1065%str1 = internal constant [13 x sbyte] c"MySource.cpp\00", section "llvm.metadata";
1066%str2 = internal constant [21 x sbyte] c"/Users/mine/sources/\00", section "llvm.metadata";
1067%str3 = internal constant [33 x sbyte] c"4.0.1 LLVM (LLVM research group)\00", section "llvm.metadata";
1068%str4 = internal constant [11 x sbyte] c"MyHeader.h\00", section "llvm.metadata";
1069...
1070</pre>
1071
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1072</div>
1073
1074<!-- ======================================================================= -->
1075<div class="doc_subsection">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1076 <a name="ccxx_global_variable">C/C++ global variable information</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1077</div>
1078
1079<div class="doc_text">
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1080
1081<p>Given an integer global variable declared as follows;</p>
1082
1083<pre>
1084int MyGlobal = 100;
1085</pre>
1086
1087<p>a C/C++ front-end would generate the following descriptors;</p>
1088
1089<pre>
1090;;
1091;; Define types used. One for global variable anchors, one for the global
1092;; variable descriptor, one for the global's basic type and one for the global's
1093;; compile unit.
1094;;
1095%<a href="#format_anchors">llvm.dbg.anchor.type</a> = type { uint, uint }
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]1096%<a href="#format_global_variables">llvm.dbg.global_variable.type</a> = type { uint, { }*, { }*, sbyte*, { }*, uint, { }*, bool, bool, { }*, uint }
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1097%<a href="#format_basic_type">llvm.dbg.basictype.type</a> = type { uint, { }*, sbyte*, { }*, int, uint, uint, uint, uint }
1098%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> = ...
1099...
1100;;
1101;; Define the global itself.
1102;;
1103%MyGlobal = global int 100
1104...
1105;;
1106;; Define the anchor for global variables. Note that the second field of the
1107;; anchor is 52, which is the same as the tag for global variables
1108;; (52 = DW_TAG_variable.)
1109;;
1110%<a href="#format_global_variables">llvm.dbg.global_variables</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { uint 0, uint 52 }, section "llvm.metadata"
1111
1112;;
1113;; Define the global variable descriptor. Note the reference to the global
1114;; variable anchor and the global variable itself.
1115;;
1116%<a href="#format_global_variables">llvm.dbg.global_variable</a> = internal constant %<a href="#format_global_variables">llvm.dbg.global_variable.type</a> {
1117 uint 52,
1118 { }* cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_global_variables">llvm.dbg.global_variables</a> to { }*),
1119 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1120 sbyte* getelementptr ([9 x sbyte]* %str1, int 0, int 0),
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]1121 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1122 uint 1,
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1123 { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype</a> to { }*),
1124 bool false,
1125 bool true,
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]1126 { }* cast (int* %MyGlobal to { }*) }, section "llvm.metadata"
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1127
1128;;
1129;; Define the basic type of 32 bit signed integer. Note that since int is an
1130;; intrinsic type the source file is NULL and line 0.
1131;;
1132%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1133 uint 36,
1134 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1135 sbyte* getelementptr ([4 x sbyte]* %str2, int 0, int 0),
1136 { }* null,
1137 int 0,
1138 uint 32,
1139 uint 32,
1140 uint 0,
1141 uint 5 }, section "llvm.metadata"
1142
1143;;
1144;; Define the names of the global variable and basic type.
1145;;
1146%str1 = internal constant [9 x sbyte] c"MyGlobal\00", section "llvm.metadata"
1147%str2 = internal constant [4 x sbyte] c"int\00", section "llvm.metadata"
1148</pre>
1149
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]1150</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1151
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1152<!-- ======================================================================= -->
1153<div class="doc_subsection">
1154 <a name="ccxx_subprogram">C/C++ function information</a>
1155</div>
1156
1157<div class="doc_text">
1158
1159<p>Given a function declared as follows;</p>
1160
1161<pre>
1162int main(int argc, char *argv[]) {
1163 return 0;
1164}
1165</pre>
1166
1167<p>a C/C++ front-end would generate the following descriptors;</p>
1168
1169<pre>
1170;;
1171;; Define types used. One for subprogram anchors, one for the subprogram
1172;; descriptor, one for the global's basic type and one for the subprogram's
1173;; compile unit.
1174;;
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]1175%<a href="#format_subprograms">llvm.dbg.subprogram.type</a> = type { uint, { }*, { }*, sbyte*, { }*, bool, bool }
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1176%<a href="#format_anchors">llvm.dbg.anchor.type</a> = type { uint, uint }
1177%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> = ...
1178
1179;;
1180;; Define the anchor for subprograms. Note that the second field of the
1181;; anchor is 46, which is the same as the tag for subprograms
1182;; (46 = DW_TAG_subprogram.)
1183;;
1184%<a href="#format_subprograms">llvm.dbg.subprograms</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { uint 0, uint 46 }, section "llvm.metadata"
1185
1186;;
1187;; Define the descriptor for the subprogram. TODO - more details.
1188;;
1189%<a href="#format_subprograms">llvm.dbg.subprogram</a> = internal constant %<a href="#format_subprograms">llvm.dbg.subprogram.type</a> {
1190 uint 46,
1191 { }* cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_subprograms">llvm.dbg.subprograms</a> to { }*),
1192 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1193 sbyte* getelementptr ([5 x sbyte]* %str1, int 0, int 0),
Jim Laskey3d11bee2006-03-15 19:10:52 +0000[diff] [blame]1194 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1195 uint 1,
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1196 { }* null,
1197 bool false,
Jim Laskey383e0092006-03-23 17:54:33 +0000[diff] [blame]1198 bool true }, section "llvm.metadata"
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1199
1200;;
1201;; Define the name of the subprogram.
1202;;
1203%str1 = internal constant [5 x sbyte] c"main\00", section "llvm.metadata"
1204
1205;;
1206;; Define the subprogram itself.
1207;;
1208int %main(int %argc, sbyte** %argv) {
1209...
1210}
1211</pre>
1212
1213</div>
1214
1215<!-- ======================================================================= -->
1216<div class="doc_subsection">
1217 <a name="ccxx_basic_types">C/C++ basic types</a>
1218</div>
1219
1220<div class="doc_text">
1221
1222<p>The following are the basic type descriptors for C/C++ core types;</p>
1223
1224</div>
1225
1226<!-- ======================================================================= -->
1227<div class="doc_subsubsection">
1228 <a name="ccxx_basic_type_bool">bool</a>
1229</div>
1230
1231<div class="doc_text">
1232
1233<pre>
1234%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1235 uint 36,
1236 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1237 sbyte* getelementptr ([5 x sbyte]* %str1, int 0, int 0),
1238 { }* null,
1239 int 0,
1240 uint 32,
1241 uint 32,
1242 uint 0,
1243 uint 2 }, section "llvm.metadata"
1244%str1 = internal constant [5 x sbyte] c"bool\00", section "llvm.metadata"
1245</pre>
1246
1247</div>
1248
1249<!-- ======================================================================= -->
1250<div class="doc_subsubsection">
1251 <a name="ccxx_basic_char">char</a>
1252</div>
1253
1254<div class="doc_text">
1255
1256<pre>
1257%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1258 uint 36,
1259 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1260 sbyte* getelementptr ([5 x sbyte]* %str1, int 0, int 0),
1261 { }* null,
1262 int 0,
1263 uint 8,
1264 uint 8,
1265 uint 0,
1266 uint 6 }, section "llvm.metadata"
1267%str1 = internal constant [5 x sbyte] c"char\00", section "llvm.metadata"
1268</pre>
1269
1270</div>
1271
1272<!-- ======================================================================= -->
1273<div class="doc_subsubsection">
1274 <a name="ccxx_basic_unsigned_char">unsigned char</a>
1275</div>
1276
1277<div class="doc_text">
1278
1279<pre>
1280%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1281 uint 36,
1282 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1283 sbyte* getelementptr ([14 x sbyte]* %str1, int 0, int 0),
1284 { }* null,
1285 int 0,
1286 uint 8,
1287 uint 8,
1288 uint 0,
1289 uint 8 }, section "llvm.metadata"
1290%str1 = internal constant [14 x sbyte] c"unsigned char\00", section "llvm.metadata"
1291</pre>
1292
1293</div>
1294
1295<!-- ======================================================================= -->
1296<div class="doc_subsubsection">
1297 <a name="ccxx_basic_short">short</a>
1298</div>
1299
1300<div class="doc_text">
1301
1302<pre>
1303%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1304 uint 36,
1305 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1306 sbyte* getelementptr ([10 x sbyte]* %str1, int 0, int 0),
1307 { }* null,
1308 int 0,
1309 uint 16,
1310 uint 16,
1311 uint 0,
1312 uint 5 }, section "llvm.metadata"
1313%str1 = internal constant [10 x sbyte] c"short int\00", section "llvm.metadata"
1314</pre>
1315
1316</div>
1317
1318<!-- ======================================================================= -->
1319<div class="doc_subsubsection">
1320 <a name="ccxx_basic_unsigned_short">unsigned short</a>
1321</div>
1322
1323<div class="doc_text">
1324
1325<pre>
1326%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1327 uint 36,
1328 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1329 sbyte* getelementptr ([19 x sbyte]* %str1, int 0, int 0),
1330 { }* null,
1331 int 0,
1332 uint 16,
1333 uint 16,
1334 uint 0,
1335 uint 7 }, section "llvm.metadata"
1336%str1 = internal constant [19 x sbyte] c"short unsigned int\00", section "llvm.metadata"
1337</pre>
1338
1339</div>
1340
1341<!-- ======================================================================= -->
1342<div class="doc_subsubsection">
1343 <a name="ccxx_basic_int">int</a>
1344</div>
1345
1346<div class="doc_text">
1347
1348<pre>
1349%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1350 uint 36,
1351 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1352 sbyte* getelementptr ([4 x sbyte]* %str1, int 0, int 0),
1353 { }* null,
1354 int 0,
1355 uint 32,
1356 uint 32,
1357 uint 0,
1358 uint 5 }, section "llvm.metadata"
1359%str1 = internal constant [4 x sbyte] c"int\00", section "llvm.metadata"
1360</pre>
1361
1362</div>
1363
1364<!-- ======================================================================= -->
1365<div class="doc_subsubsection">
1366 <a name="ccxx_basic_unsigned_int">unsigned int</a>
1367</div>
1368
1369<div class="doc_text">
1370
1371<pre>
1372%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1373 uint 36,
1374 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1375 sbyte* getelementptr ([13 x sbyte]* %str1, int 0, int 0),
1376 { }* null,
1377 int 0,
1378 uint 32,
1379 uint 32,
1380 uint 0,
1381 uint 7 }, section "llvm.metadata"
1382%str1 = internal constant [13 x sbyte] c"unsigned int\00", section "llvm.metadata"
1383</pre>
1384
1385</div>
1386
1387<!-- ======================================================================= -->
1388<div class="doc_subsubsection">
1389 <a name="ccxx_basic_long_long">long long</a>
1390</div>
1391
1392<div class="doc_text">
1393
1394<pre>
1395%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1396 uint 36,
1397 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1398 sbyte* getelementptr ([14 x sbyte]* %str1, int 0, int 0),
1399 { }* null,
1400 int 0,
1401 uint 64,
1402 uint 64,
1403 uint 0,
1404 uint 5 }, section "llvm.metadata"
1405%str1 = internal constant [14 x sbyte] c"long long int\00", section "llvm.metadata"
1406</pre>
1407
1408</div>
1409
1410<!-- ======================================================================= -->
1411<div class="doc_subsubsection">
1412 <a name="ccxx_basic_unsigned_long_long">unsigned long long</a>
1413</div>
1414
1415<div class="doc_text">
1416
1417<pre>
1418%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1419 uint 36,
1420 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1421 sbyte* getelementptr ([23 x sbyte]* %str1, int 0, int 0),
1422 { }* null,
1423 int 0,
1424 uint 64,
1425 uint 64,
1426 uint 0,
1427 uint 7 }, section "llvm.metadata"
1428%str1 = internal constant [23 x sbyte] c"long long unsigned int\00", section "llvm.metadata"
1429</pre>
1430
1431</div>
1432
1433<!-- ======================================================================= -->
1434<div class="doc_subsubsection">
1435 <a name="ccxx_basic_float">float</a>
1436</div>
1437
1438<div class="doc_text">
1439
1440<pre>
1441%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1442 uint 36,
1443 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1444 sbyte* getelementptr ([6 x sbyte]* %str1, int 0, int 0),
1445 { }* null,
1446 int 0,
1447 uint 32,
1448 uint 32,
1449 uint 0,
1450 uint 4 }, section "llvm.metadata"
1451%str1 = internal constant [6 x sbyte] c"float\00", section "llvm.metadata"
1452</pre>
1453
1454</div>
1455
1456<!-- ======================================================================= -->
1457<div class="doc_subsubsection">
1458 <a name="ccxx_basic_double">double</a>
1459</div>
1460
1461<div class="doc_text">
1462
1463<pre>
1464%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1465 uint 36,
1466 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1467 sbyte* getelementptr ([7 x sbyte]* %str1, int 0, int 0),
1468 { }* null,
1469 int 0,
1470 uint 64,
1471 uint 64,
1472 uint 0,
1473 uint 4 }, section "llvm.metadata"
1474%str1 = internal constant [7 x sbyte] c"double\00", section "llvm.metadata"
1475</pre>
1476
1477</div>
1478
1479<!-- ======================================================================= -->
1480<div class="doc_subsection">
1481 <a name="ccxx_derived_types">C/C++ derived types</a>
1482</div>
1483
1484<div class="doc_text">
1485
1486<p>Given the following as an example of C/C++ derived type;</p>
1487
1488<pre>
1489typedef const int *IntPtr;
1490</pre>
1491
1492<p>a C/C++ front-end would generate the following descriptors;</p>
1493
1494<pre>
1495;;
1496;; Define the typedef "IntPtr".
1497;;
1498%<a href="#format_derived_type">llvm.dbg.derivedtype1</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> {
1499 uint 22,
1500 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1501 sbyte* getelementptr ([7 x sbyte]* %str1, int 0, int 0),
1502 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1503 int 1,
1504 uint 0,
1505 uint 0,
1506 uint 0,
1507 { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype2</a> to { }*) }, section "llvm.metadata"
1508%str1 = internal constant [7 x sbyte] c"IntPtr\00", section "llvm.metadata"
1509
1510;;
1511;; Define the pointer type.
1512;;
1513%<a href="#format_derived_type">llvm.dbg.derivedtype2</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> {
1514 uint 15,
1515 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
Jim Laskey4d9b10b2006-03-14 18:50:50 +0000[diff] [blame]1516 sbyte* null,
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1517 { }* null,
1518 int 0,
1519 uint 32,
1520 uint 32,
1521 uint 0,
1522 { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype3</a> to { }*) }, section "llvm.metadata"
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1523
1524;;
1525;; Define the const type.
1526;;
1527%<a href="#format_derived_type">llvm.dbg.derivedtype3</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> {
1528 uint 38,
1529 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
Jim Laskey4d9b10b2006-03-14 18:50:50 +0000[diff] [blame]1530 sbyte* null,
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1531 { }* null,
1532 int 0,
1533 uint 0,
1534 uint 0,
1535 uint 0,
1536 { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype1</a> to { }*) }, section "llvm.metadata"
1537
1538;;
1539;; Define the int type.
1540;;
1541%<a href="#format_basic_type">llvm.dbg.basictype1</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1542 uint 36,
1543 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
Jim Laskey4d9b10b2006-03-14 18:50:50 +0000[diff] [blame]1544 sbyte* getelementptr ([4 x sbyte]* %str2, int 0, int 0),
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1545 { }* null,
1546 int 0,
1547 uint 32,
1548 uint 32,
1549 uint 0,
1550 uint 5 }, section "llvm.metadata"
Jim Laskey4d9b10b2006-03-14 18:50:50 +0000[diff] [blame]1551%str2 = internal constant [4 x sbyte] c"int\00", section "llvm.metadata"
Jim Laskeycec12a52006-03-14 18:08:46 +0000[diff] [blame]1552</pre>
1553
1554</div>
1555
1556<!-- ======================================================================= -->
1557<div class="doc_subsection">
1558 <a name="ccxx_composite_types">C/C++ struct/union types</a>
1559</div>
1560
1561<div class="doc_text">
1562
1563<p>Given the following as an example of C/C++ struct type;</p>
1564
1565<pre>
1566struct Color {
1567 unsigned Red;
1568 unsigned Green;
1569 unsigned Blue;
1570};
1571</pre>
1572
1573<p>a C/C++ front-end would generate the following descriptors;</p>
1574
1575<pre>
1576;;
1577;; Define basic type for unsigned int.
1578;;
1579%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> {
1580 uint 36,
1581 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1582 sbyte* getelementptr ([13 x sbyte]* %str1, int 0, int 0),
1583 { }* null,
1584 int 0,
1585 uint 32,
1586 uint 32,
1587 uint 0,
1588 uint 7 }, section "llvm.metadata"
1589%str1 = internal constant [13 x sbyte] c"unsigned int\00", section "llvm.metadata"
1590
1591;;
1592;; Define composite type for struct Color.
1593;;
1594%<a href="#format_composite_type">llvm.dbg.compositetype</a> = internal constant %<a href="#format_composite_type">llvm.dbg.compositetype.type</a> {
1595 uint 19,
1596 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1597 sbyte* getelementptr ([6 x sbyte]* %str2, int 0, int 0),
1598 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1599 int 1,
1600 uint 96,
1601 uint 32,
1602 uint 0,
1603 { }* null,
1604 { }* cast ([3 x { }*]* %llvm.dbg.array to { }*) }, section "llvm.metadata"
1605%str2 = internal constant [6 x sbyte] c"Color\00", section "llvm.metadata"
1606
1607;;
1608;; Define the Red field.
1609;;
1610%<a href="#format_derived_type">llvm.dbg.derivedtype1</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> {
1611 uint 13,
1612 { }* null,
1613 sbyte* getelementptr ([4 x sbyte]* %str3, int 0, int 0),
1614 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1615 int 2,
1616 uint 32,
1617 uint 32,
1618 uint 0,
1619 { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype</a> to { }*) }, section "llvm.metadata"
1620%str3 = internal constant [4 x sbyte] c"Red\00", section "llvm.metadata"
1621
1622;;
1623;; Define the Green field.
1624;;
1625%<a href="#format_derived_type">llvm.dbg.derivedtype2</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> {
1626 uint 13,
1627 { }* null,
1628 sbyte* getelementptr ([6 x sbyte]* %str4, int 0, int 0),
1629 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1630 int 3,
1631 uint 32,
1632 uint 32,
1633 uint 32,
1634 { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype</a> to { }*) }, section "llvm.metadata"
1635%str4 = internal constant [6 x sbyte] c"Green\00", section "llvm.metadata"
1636
1637;;
1638;; Define the Blue field.
1639;;
1640%<a href="#format_derived_type">llvm.dbg.derivedtype3</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> {
1641 uint 13,
1642 { }* null,
1643 sbyte* getelementptr ([5 x sbyte]* %str5, int 0, int 0),
1644 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1645 int 4,
1646 uint 32,
1647 uint 32,
1648 uint 64,
1649 { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype</a> to { }*) }, section "llvm.metadata"
1650%str5 = internal constant [5 x sbyte] c"Blue\00", section "llvm.metadata"
1651
1652;;
1653;; Define the array of fields used by the composite type Color.
1654;;
1655%llvm.dbg.array = internal constant [3 x { }*] [
1656 { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype1</a> to { }*),
1657 { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype2</a> to { }*),
1658 { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype3</a> to { }*) ], section "llvm.metadata"
1659</pre>
1660
1661</div>
1662
1663<!-- ======================================================================= -->
1664<div class="doc_subsection">
1665 <a name="ccxx_enumeration_types">C/C++ enumeration types</a>
1666</div>
1667
1668<div class="doc_text">
1669
1670<p>Given the following as an example of C/C++ enumeration type;</p>
1671
1672<pre>
1673enum Trees {
1674 Spruce = 100,
1675 Oak = 200,
1676 Maple = 300
1677};
1678</pre>
1679
1680<p>a C/C++ front-end would generate the following descriptors;</p>
1681
1682<pre>
1683;;
1684;; Define composite type for enum Trees
1685;;
1686%<a href="#format_composite_type">llvm.dbg.compositetype</a> = internal constant %<a href="#format_composite_type">llvm.dbg.compositetype.type</a> {
1687 uint 4,
1688 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1689 sbyte* getelementptr ([6 x sbyte]* %str1, int 0, int 0),
1690 { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*),
1691 int 1,
1692 uint 32,
1693 uint 32,
1694 uint 0,
1695 { }* null,
1696 { }* cast ([3 x { }*]* %llvm.dbg.array to { }*) }, section "llvm.metadata"
1697%str1 = internal constant [6 x sbyte] c"Trees\00", section "llvm.metadata"
1698
1699;;
1700;; Define Spruce enumerator.
1701;;
1702%<a href="#format_enumeration">llvm.dbg.enumerator1</a> = internal constant %<a href="#format_enumeration">llvm.dbg.enumerator.type</a> {
1703 uint 40,
1704 sbyte* getelementptr ([7 x sbyte]* %str2, int 0, int 0),
1705 int 100 }, section "llvm.metadata"
1706%str2 = internal constant [7 x sbyte] c"Spruce\00", section "llvm.metadata"
1707
1708;;
1709;; Define Oak enumerator.
1710;;
1711%<a href="#format_enumeration">llvm.dbg.enumerator2</a> = internal constant %<a href="#format_enumeration">llvm.dbg.enumerator.type</a> {
1712 uint 40,
1713 sbyte* getelementptr ([4 x sbyte]* %str3, int 0, int 0),
1714 int 200 }, section "llvm.metadata"
1715%str3 = internal constant [4 x sbyte] c"Oak\00", section "llvm.metadata"
1716
1717;;
1718;; Define Maple enumerator.
1719;;
1720%<a href="#format_enumeration">llvm.dbg.enumerator3</a> = internal constant %<a href="#format_enumeration">llvm.dbg.enumerator.type</a> {
1721 uint 40,
1722 sbyte* getelementptr ([6 x sbyte]* %str4, int 0, int 0),
1723 int 300 }, section "llvm.metadata"
1724%str4 = internal constant [6 x sbyte] c"Maple\00", section "llvm.metadata"
1725
1726;;
1727;; Define the array of enumerators used by composite type Trees.
1728;;
1729%llvm.dbg.array = internal constant [3 x { }*] [
1730 { }* cast (%<a href="#format_enumeration">llvm.dbg.enumerator.type</a>* %<a href="#format_enumeration">llvm.dbg.enumerator1</a> to { }*),
1731 { }* cast (%<a href="#format_enumeration">llvm.dbg.enumerator.type</a>* %<a href="#format_enumeration">llvm.dbg.enumerator2</a> to { }*),
1732 { }* cast (%<a href="#format_enumeration">llvm.dbg.enumerator.type</a>* %<a href="#format_enumeration">llvm.dbg.enumerator3</a> to { }*) ], section "llvm.metadata"
1733</pre>
1734
1735</div>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1736
1737<!-- *********************************************************************** -->
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1738
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1739<hr>
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1740<address>
1741 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
1742 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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1745
1746 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]1747 <a href="http://llvm.org">LLVM Compiler Infrastructure</a><br>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1748 Last modified: $Date$
Misha Brukman82873732004-05-12 19:21:57 +0000[diff] [blame]1749</address>
Chris Lattnerbdfb3392004-01-05 05:06:33 +0000[diff] [blame]1750
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