diff options
Diffstat (limited to 'docs/SourceLevelDebugging.html')
| -rw-r--r-- | docs/SourceLevelDebugging.html | 1926 |
1 files changed, 1926 insertions, 0 deletions
diff --git a/docs/SourceLevelDebugging.html b/docs/SourceLevelDebugging.html new file mode 100644 index 0000000..17851b7 --- /dev/null +++ b/docs/SourceLevelDebugging.html @@ -0,0 +1,1926 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" + "http://www.w3.org/TR/html4/strict.dtd"> +<html> +<head> + <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> + <title>Source Level Debugging with LLVM</title> + <link rel="stylesheet" href="llvm.css" type="text/css"> +</head> +<body> + +<div class="doc_title">Source Level Debugging with LLVM</div> + +<table class="layout" style="width:100%"> + <tr class="layout"> + <td class="left"> +<ul> + <li><a href="#introduction">Introduction</a> + <ol> + <li><a href="#phil">Philosophy behind LLVM debugging information</a></li> + <li><a href="#consumers">Debug information consumers</a></li> + <li><a href="#debugopt">Debugging optimized code</a></li> + </ol></li> + <li><a href="#format">Debugging information format</a> + <ol> + <li><a href="#debug_info_descriptors">Debug information descriptors</a> + <ul> + <li><a href="#format_anchors">Anchor descriptors</a></li> + <li><a href="#format_compile_units">Compile unit descriptors</a></li> + <li><a href="#format_global_variables">Global variable descriptors</a></li> + <li><a href="#format_subprograms">Subprogram descriptors</a></li> + <li><a href="#format_blocks">Block descriptors</a></li> + <li><a href="#format_basic_type">Basic type descriptors</a></li> + <li><a href="#format_derived_type">Derived type descriptors</a></li> + <li><a href="#format_composite_type">Composite type descriptors</a></li> + <li><a href="#format_subrange">Subrange descriptors</a></li> + <li><a href="#format_enumeration">Enumerator descriptors</a></li> + <li><a href="#format_variables">Local variables</a></li> + </ul></li> + <li><a href="#format_common_intrinsics">Debugger intrinsic functions</a> + <ul> + <li><a href="#format_common_stoppoint">llvm.dbg.stoppoint</a></li> + <li><a href="#format_common_func_start">llvm.dbg.func.start</a></li> + <li><a href="#format_common_region_start">llvm.dbg.region.start</a></li> + <li><a href="#format_common_region_end">llvm.dbg.region.end</a></li> + <li><a href="#format_common_declare">llvm.dbg.declare</a></li> + </ul></li> + <li><a href="#format_common_stoppoints">Representing stopping points in the + source program</a></li> + </ol></li> + <li><a href="#ccxx_frontend">C/C++ front-end specific debug information</a> + <ol> + <li><a href="#ccxx_compile_units">C/C++ source file information</a></li> + <li><a href="#ccxx_global_variable">C/C++ global variable information</a></li> + <li><a href="#ccxx_subprogram">C/C++ function information</a></li> + <li><a href="#ccxx_basic_types">C/C++ basic types</a></li> + <li><a href="#ccxx_derived_types">C/C++ derived types</a></li> + <li><a href="#ccxx_composite_types">C/C++ struct/union types</a></li> + <li><a href="#ccxx_enumeration_types">C/C++ enumeration types</a></li> + </ol></li> +</ul> +</td> +<td class="right"> +<img src="img/venusflytrap.jpg" alt="A leafy and green bug eater" width="247" +height="369"> +</td> +</tr></table> + +<div class="doc_author"> + <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a> + and <a href="mailto:jlaskey@mac.com">Jim Laskey</a></p> +</div> + + +<!-- *********************************************************************** --> +<div class="doc_section"><a name="introduction">Introduction</a></div> +<!-- *********************************************************************** --> + +<div class="doc_text"> + +<p>This document is the central repository for all information pertaining to + debug information in LLVM. It describes the <a href="#format">actual format + that the LLVM debug information</a> takes, which is useful for those + interested in creating front-ends or dealing directly with the information. + Further, this document provides specifc examples of what debug information + for C/C++.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="phil">Philosophy behind LLVM debugging information</a> +</div> + +<div class="doc_text"> + +<p>The idea of the LLVM debugging information is to capture how the important + pieces of the source-language's Abstract Syntax Tree map onto LLVM code. + Several design aspects have shaped the solution that appears here. The + important ones are:</p> + +<ul> + <li>Debugging information should have very little impact on the rest of the + compiler. No transformations, analyses, or code generators should need to + be modified because of debugging information.</li> + + <li>LLVM optimizations should interact in <a href="#debugopt">well-defined and + easily described ways</a> with the debugging information.</li> + + <li>Because LLVM is designed to support arbitrary programming languages, + LLVM-to-LLVM tools should not need to know anything about the semantics of + the source-level-language.</li> + + <li>Source-level languages are often <b>widely</b> different from one another. + LLVM should not put any restrictions of the flavor of the source-language, + and the debugging information should work with any language.</li> + + <li>With code generator support, it should be possible to use an LLVM compiler + to compile a program to native machine code and standard debugging + formats. This allows compatibility with traditional machine-code level + debuggers, like GDB or DBX.</li> +</ul> + +<p>The approach used by the LLVM implementation is to use a small set + of <a href="#format_common_intrinsics">intrinsic functions</a> to define a + mapping between LLVM program objects and the source-level objects. The + description of the source-level program is maintained in LLVM global + variables in an <a href="#ccxx_frontend">implementation-defined format</a> + (the C/C++ front-end currently uses working draft 7 of + the <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3 + standard</a>).</p> + +<p>When a program is being debugged, a debugger interacts with the user and + turns the stored debug information into source-language specific information. + As such, a debugger must be aware of the source-language, and is thus tied to + a specific language or family of languages.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="consumers">Debug information consumers</a> +</div> + +<div class="doc_text"> + +<p>The role of debug information is to provide meta information normally + stripped away during the compilation process. This meta information provides + an LLVM user a relationship between generated code and the original program + source code.</p> + +<p>Currently, debug information is consumed by the DwarfWriter to produce dwarf + information used by the gdb debugger. Other targets could use the same + information to produce stabs or other debug forms.</p> + +<p>It would also be reasonable to use debug information to feed profiling tools + for analysis of generated code, or, tools for reconstructing the original + source from generated code.</p> + +<p>TODO - expound a bit more.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="debugopt">Debugging optimized code</a> +</div> + +<div class="doc_text"> + +<p>An extremely high priority of LLVM debugging information is to make it + interact well with optimizations and analysis. In particular, the LLVM debug + information provides the following guarantees:</p> + +<ul> + <li>LLVM debug information <b>always provides information to accurately read + the source-level state of the program</b>, regardless of which LLVM + optimizations have been run, and without any modification to the + optimizations themselves. However, some optimizations may impact the + ability to modify the current state of the program with a debugger, such + as setting program variables, or calling functions that have been + deleted.</li> + + <li>LLVM optimizations gracefully interact with debugging information. If + they are not aware of debug information, they are automatically disabled + as necessary in the cases that would invalidate the debug info. This + retains the LLVM features, making it easy to write new + transformations.</li> + + <li>As desired, LLVM optimizations can be upgraded to be aware of the LLVM + debugging information, allowing them to update the debugging information + as they perform aggressive optimizations. This means that, with effort, + the LLVM optimizers could optimize debug code just as well as non-debug + code.</li> + + <li>LLVM debug information does not prevent many important optimizations from + happening (for example inlining, basic block reordering/merging/cleanup, + tail duplication, etc), further reducing the amount of the compiler that + eventually is "aware" of debugging information.</li> + + <li>LLVM debug information is automatically optimized along with the rest of + the program, using existing facilities. For example, duplicate + information is automatically merged by the linker, and unused information + is automatically removed.</li> +</ul> + +<p>Basically, the debug information allows you to compile a program with + "<tt>-O0 -g</tt>" and get full debug information, allowing you to arbitrarily + modify the program as it executes from a debugger. Compiling a program with + "<tt>-O3 -g</tt>" gives you full debug information that is always available + and accurate for reading (e.g., you get accurate stack traces despite tail + call elimination and inlining), but you might lose the ability to modify the + program and call functions where were optimized out of the program, or + inlined away completely.</p> + +<p><a href="TestingGuide.html#quicktestsuite">LLVM test suite</a> provides a + framework to test optimizer's handling of debugging information. It can be + run like this:</p> + +<div class="doc_code"> +<pre> +% cd llvm/projects/test-suite/MultiSource/Benchmarks # or some other level +% make TEST=dbgopt +</pre> +</div> + +<p>This will test impact of debugging information on optimization passes. If + debugging information influences optimization passes then it will be reported + as a failure. See <a href="TestingGuide.html">TestingGuide</a> for more + information on LLVM test infrastructure and how to run various tests.</p> + +</div> + +<!-- *********************************************************************** --> +<div class="doc_section"> + <a name="format">Debugging information format</a> +</div> +<!-- *********************************************************************** --> + +<div class="doc_text"> + +<p>LLVM debugging information has been carefully designed to make it possible + for the optimizer to optimize the program and debugging information without + necessarily having to know anything about debugging information. In + particular, the global constant merging pass automatically eliminates + duplicated debugging information (often caused by header files), the global + dead code elimination pass automatically deletes debugging information for a + function if it decides to delete the function, and the linker eliminates + debug information when it merges <tt>linkonce</tt> functions.</p> + +<p>To do this, most of the debugging information (descriptors for types, + variables, functions, source files, etc) is inserted by the language + front-end in the form of LLVM global variables. These LLVM global variables + are no different from any other global variables, except that they have a web + of LLVM intrinsic functions that point to them. If the last references to a + particular piece of debugging information are deleted (for example, by the + <tt>-globaldce</tt> pass), the extraneous debug information will + automatically become dead and be removed by the optimizer.</p> + +<p>Debug information is designed to be agnostic about the target debugger and + debugging information representation (e.g. DWARF/Stabs/etc). It uses a + generic machine debug information pass to decode the information that + represents variables, types, functions, namespaces, etc: this allows for + arbitrary source-language semantics and type-systems to be used, as long as + there is a module written for the target debugger to interpret the + information. In addition, debug global variables are declared in + the <tt>"llvm.metadata"</tt> section. All values declared in this section + are stripped away after target debug information is constructed and before + the program object is emitted.</p> + +<p>To provide basic functionality, the LLVM debugger does have to make some + assumptions about the source-level language being debugged, though it keeps + these to a minimum. The only common features that the LLVM debugger assumes + exist are <a href="#format_compile_units">source files</a>, + and <a href="#format_global_variables">program objects</a>. These abstract + objects are used by a debugger to form stack traces, show information about + local variables, etc.</p> + +<p>This section of the documentation first describes the representation aspects + common to any source-language. The <a href="#ccxx_frontend">next section</a> + describes the data layout conventions used by the C and C++ front-ends.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="debug_info_descriptors">Debug information descriptors</a> +</div> + +<div class="doc_text"> + +<p>In consideration of the complexity and volume of debug information, LLVM + provides a specification for well formed debug global variables. The + constant value of each of these globals is one of a limited set of + structures, known as debug descriptors.</p> + +<p>Consumers of LLVM debug information expect the descriptors for program + objects to start in a canonical format, but the descriptors can include + additional information appended at the end that is source-language + specific. All LLVM debugging information is versioned, allowing backwards + compatibility in the case that the core structures need to change in some + way. Also, all debugging information objects start with a tag to indicate + what type of object it is. The source-language is allowed to define its own + objects, by using unreserved tag numbers. We recommend using with tags in + the range 0x1000 thru 0x2000 (there is a defined enum DW_TAG_user_base = + 0x1000.)</p> + +<p>The fields of debug descriptors used internally by LLVM (MachineModuleInfo) + are restricted to only the simple data types <tt>int</tt>, <tt>uint</tt>, + <tt>bool</tt>, <tt>float</tt>, <tt>double</tt>, <tt>i8*</tt> and + <tt>{ }*</tt>. References to arbitrary values are handled using a + <tt>{ }*</tt> and a cast to <tt>{ }*</tt> expression; typically + references to other field descriptors, arrays of descriptors or global + variables.</p> + +<div class="doc_code"> +<pre> +%llvm.dbg.object.type = type { + uint, ;; A tag + ... +} +</pre> +</div> + +<p><a name="LLVMDebugVersion">The first field of a descriptor is always an + <tt>uint</tt> containing a tag value identifying the content of the + descriptor. The remaining fields are specific to the descriptor. The values + of tags are loosely bound to the tag values of DWARF information entries. + However, that does not restrict the use of the information supplied to DWARF + targets. To facilitate versioning of debug information, the tag is augmented + with the current debug version (LLVMDebugVersion = 4 << 16 or 0x40000 or + 262144.)</a></p> + +<p>The details of the various descriptors follow.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_anchors">Anchor descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_anchors">llvm.dbg.anchor.type</a> = type { + i32, ;; Tag = 0 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> + i32 ;; Tag of descriptors grouped by the anchor +} +</pre> +</div> + +<p>One important aspect of the LLVM debug representation is that it allows the + LLVM debugger to efficiently index all of the global objects without having + to scan the program. To do this, all of the global objects use "anchor" + descriptors with designated names. All of the global objects of a particular + type (e.g., compile units) contain a pointer to the anchor. This pointer + allows a debugger to use def-use chains to find all global objects of that + type.</p> + +<p>The following names are recognized as anchors by LLVM:</p> + +<div class="doc_code"> +<pre> +%<a href="#format_compile_units">llvm.dbg.compile_units</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { + i32 0, + i32 17 +} ;; DW_TAG_compile_unit +%<a href="#format_global_variables">llvm.dbg.global_variables</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { + i32 0, + i32 52 +} ;; DW_TAG_variable +%<a href="#format_subprograms">llvm.dbg.subprograms</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> { + i32 0, + i32 46 +} ;; DW_TAG_subprogram +</pre> +</div> + +<p>Using anchors in this way (where the compile unit descriptor points to the + anchors, as opposed to having a list of compile unit descriptors) allows for + the standard dead global elimination and merging passes to automatically + remove unused debugging information. If the globals were kept track of + through lists, there would always be an object pointing to the descriptors, + thus would never be deleted.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_compile_units">Compile unit descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> = type { + i32, ;; Tag = 17 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_compile_unit) + { }*, ;; Compile unit anchor = cast = (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_units</a> to { }*) + i32, ;; DWARF language identifier (ex. DW_LANG_C89) + i8*, ;; Source file name + i8*, ;; Source file directory (includes trailing slash) + i8* ;; Producer (ex. "4.0.1 LLVM (LLVM research group)") + i1, ;; True if this is a main compile unit. + i1, ;; True if this is optimized. + i8*, ;; Flags + i32 ;; Runtime version +} +</pre> +</div> + +<p>These descriptors contain a source language ID for the file (we use the DWARF + 3.0 ID numbers, such as <tt>DW_LANG_C89</tt>, <tt>DW_LANG_C_plus_plus</tt>, + <tt>DW_LANG_Cobol74</tt>, etc), three strings describing the filename, + working directory of the compiler, and an identifier string for the compiler + that produced it.</p> + +<p>Compile unit descriptors provide the root context for objects declared in a + specific source file. Global variables and top level functions would be + defined using this context. Compile unit descriptors also provide context + for source line correspondence.</p> + +<p>Each input file is encoded as a separate compile unit in LLVM debugging + information output. However, many target specific tool chains prefer to + encode only one compile unit in an object file. In this situation, the LLVM + code generator will include debugging information entities in the compile + unit that is marked as main compile unit. The code generator accepts maximum + one main compile unit per module. If a module does not contain any main + compile unit then the code generator will emit multiple compile units in the + output object file.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_global_variables">Global variable descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_global_variables">llvm.dbg.global_variable.type</a> = type { + i32, ;; Tag = 52 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_variable) + { }*, ;; Global variable anchor = cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_global_variables">llvm.dbg.global_variables</a> to { }*), + { }*, ;; Reference to context descriptor + i8*, ;; Name + i8*, ;; Display name (fully qualified C++ name) + i8*, ;; MIPS linkage name (for C++) + { }*, ;; Reference to compile unit where defined + i32, ;; Line number where defined + { }*, ;; Reference to type descriptor + i1, ;; True if the global is local to compile unit (static) + i1, ;; True if the global is defined in the compile unit (not extern) + { }* ;; Reference to the global variable +} +</pre> +</div> + +<p>These descriptors provide debug information about globals variables. The +provide details such as name, type and where the variable is defined.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_subprograms">Subprogram descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_subprograms">llvm.dbg.subprogram.type</a> = type { + i32, ;; Tag = 46 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subprogram) + { }*, ;; Subprogram anchor = cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_subprograms">llvm.dbg.subprograms</a> to { }*), + { }*, ;; Reference to context descriptor + i8*, ;; Name + i8*, ;; Display name (fully qualified C++ name) + i8*, ;; MIPS linkage name (for C++) + { }*, ;; Reference to compile unit where defined + i32, ;; Line number where defined + { }*, ;; Reference to type descriptor + i1, ;; True if the global is local to compile unit (static) + i1 ;; True if the global is defined in the compile unit (not extern) +} +</pre> +</div> + +<p>These descriptors provide debug information about functions, methods and + subprograms. They provide details such as name, return types and the source + location where the subprogram is defined.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_blocks">Block descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_blocks">llvm.dbg.block</a> = type { + i32, ;; Tag = 13 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_lexical_block) + { }* ;; Reference to context descriptor +} +</pre> +</div> + +<p>These descriptors provide debug information about nested blocks within a + subprogram. The array of member descriptors is used to define local + variables and deeper nested blocks.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_basic_type">Basic type descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype.type</a> = type { + i32, ;; Tag = 36 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_base_type) + { }*, ;; Reference to context (typically a compile unit) + i8*, ;; Name (may be "" for anonymous types) + { }*, ;; Reference to compile unit where defined (may be NULL) + i32, ;; Line number where defined (may be 0) + i64, ;; Size in bits + i64, ;; Alignment in bits + i64, ;; Offset in bits + i32, ;; Flags + i32 ;; DWARF type encoding +} +</pre> +</div> + +<p>These descriptors define primitive types used in the code. Example int, bool + and float. The context provides the scope of the type, which is usually the + top level. Since basic types are not usually user defined the compile unit + and line number can be left as NULL and 0. The size, alignment and offset + are expressed in bits and can be 64 bit values. The alignment is used to + round the offset when embedded in a + <a href="#format_composite_type">composite type</a> (example to keep float + doubles on 64 bit boundaries.) The offset is the bit offset if embedded in + a <a href="#format_composite_type">composite type</a>.</p> + +<p>The type encoding provides the details of the type. The values are typically + one of the following:</p> + +<div class="doc_code"> +<pre> +DW_ATE_address = 1 +DW_ATE_boolean = 2 +DW_ATE_float = 4 +DW_ATE_signed = 5 +DW_ATE_signed_char = 6 +DW_ATE_unsigned = 7 +DW_ATE_unsigned_char = 8 +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_derived_type">Derived type descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> = type { + i32, ;; Tag (see below) + { }*, ;; Reference to context + i8*, ;; Name (may be "" for anonymous types) + { }*, ;; Reference to compile unit where defined (may be NULL) + i32, ;; Line number where defined (may be 0) + i32, ;; Size in bits + i32, ;; Alignment in bits + i32, ;; Offset in bits + { }* ;; Reference to type derived from +} +</pre> +</div> + +<p>These descriptors are used to define types derived from other types. The +value of the tag varies depending on the meaning. The following are possible +tag values:</p> + +<div class="doc_code"> +<pre> +DW_TAG_formal_parameter = 5 +DW_TAG_member = 13 +DW_TAG_pointer_type = 15 +DW_TAG_reference_type = 16 +DW_TAG_typedef = 22 +DW_TAG_const_type = 38 +DW_TAG_volatile_type = 53 +DW_TAG_restrict_type = 55 +</pre> +</div> + +<p><tt>DW_TAG_member</tt> is used to define a member of + a <a href="#format_composite_type">composite type</a> + or <a href="#format_subprograms">subprogram</a>. The type of the member is + the <a href="#format_derived_type">derived + type</a>. <tt>DW_TAG_formal_parameter</tt> is used to define a member which + is a formal argument of a subprogram.</p> + +<p><tt>DW_TAG_typedef</tt> is used to provide a name for the derived type.</p> + +<p><tt>DW_TAG_pointer_type</tt>,<tt>DW_TAG_reference_type</tt>, + <tt>DW_TAG_const_type</tt>, <tt>DW_TAG_volatile_type</tt> + and <tt>DW_TAG_restrict_type</tt> are used to qualify + the <a href="#format_derived_type">derived type</a>. </p> + +<p><a href="#format_derived_type">Derived type</a> location can be determined + from the compile unit and line number. The size, alignment and offset are + expressed in bits and can be 64 bit values. The alignment is used to round + the offset when embedded in a <a href="#format_composite_type">composite + type</a> (example to keep float doubles on 64 bit boundaries.) The offset is + the bit offset if embedded in a <a href="#format_composite_type">composite + type</a>.</p> + +<p>Note that the <tt>void *</tt> type is expressed as a + <tt>llvm.dbg.derivedtype.type</tt> with tag of <tt>DW_TAG_pointer_type</tt> + and <tt>NULL</tt> derived type.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_composite_type">Composite type descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_composite_type">llvm.dbg.compositetype.type</a> = type { + i32, ;; Tag (see below) + { }*, ;; Reference to context + i8*, ;; Name (may be "" for anonymous types) + { }*, ;; Reference to compile unit where defined (may be NULL) + i32, ;; Line number where defined (may be 0) + i64, ;; Size in bits + i64, ;; Alignment in bits + i64, ;; Offset in bits + i32, ;; Flags + { }*, ;; Reference to type derived from + { }*, ;; Reference to array of member descriptors + i32 ;; Runtime languages +} +</pre> +</div> + +<p>These descriptors are used to define types that are composed of 0 or more +elements. The value of the tag varies depending on the meaning. The following +are possible tag values:</p> + +<div class="doc_code"> +<pre> +DW_TAG_array_type = 1 +DW_TAG_enumeration_type = 4 +DW_TAG_structure_type = 19 +DW_TAG_union_type = 23 +DW_TAG_vector_type = 259 +DW_TAG_subroutine_type = 21 +DW_TAG_inheritance = 28 +</pre> +</div> + +<p>The vector flag indicates that an array type is a native packed vector.</p> + +<p>The members of array types (tag = <tt>DW_TAG_array_type</tt>) or vector types + (tag = <tt>DW_TAG_vector_type</tt>) are <a href="#format_subrange">subrange + descriptors</a>, each representing the range of subscripts at that level of + indexing.</p> + +<p>The members of enumeration types (tag = <tt>DW_TAG_enumeration_type</tt>) are + <a href="#format_enumeration">enumerator descriptors</a>, each representing + the definition of enumeration value for the set.</p> + +<p>The members of structure (tag = <tt>DW_TAG_structure_type</tt>) or union (tag + = <tt>DW_TAG_union_type</tt>) types are any one of + the <a href="#format_basic_type">basic</a>, + <a href="#format_derived_type">derived</a> + or <a href="#format_composite_type">composite</a> type descriptors, each + representing a field member of the structure or union.</p> + +<p>For C++ classes (tag = <tt>DW_TAG_structure_type</tt>), member descriptors + provide information about base classes, static members and member + functions. If a member is a <a href="#format_derived_type">derived type + descriptor</a> and has a tag of <tt>DW_TAG_inheritance</tt>, then the type + represents a base class. If the member of is + a <a href="#format_global_variables">global variable descriptor</a> then it + represents a static member. And, if the member is + a <a href="#format_subprograms">subprogram descriptor</a> then it represents + a member function. For static members and member + functions, <tt>getName()</tt> returns the members link or the C++ mangled + name. <tt>getDisplayName()</tt> the simplied version of the name.</p> + +<p>The first member of subroutine (tag = <tt>DW_TAG_subroutine_type</tt>) type + elements is the return type for the subroutine. The remaining elements are + the formal arguments to the subroutine.</p> + +<p><a href="#format_composite_type">Composite type</a> location can be + determined from the compile unit and line number. The size, alignment and + offset are expressed in bits and can be 64 bit values. The alignment is used + to round the offset when embedded in + a <a href="#format_composite_type">composite type</a> (as an example, to keep + float doubles on 64 bit boundaries.) The offset is the bit offset if embedded + in a <a href="#format_composite_type">composite type</a>.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_subrange">Subrange descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_subrange">llvm.dbg.subrange.type</a> = type { + i32, ;; Tag = 33 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_subrange_type) + i64, ;; Low value + i64 ;; High value +} +</pre> +</div> + +<p>These descriptors are used to define ranges of array subscripts for an array + <a href="#format_composite_type">composite type</a>. The low value defines + the lower bounds typically zero for C/C++. The high value is the upper + bounds. Values are 64 bit. High - low + 1 is the size of the array. If low + == high the array will be unbounded.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_enumeration">Enumerator descriptors</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_enumeration">llvm.dbg.enumerator.type</a> = type { + i32, ;; Tag = 40 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a> (DW_TAG_enumerator) + i8*, ;; Name + i64 ;; Value +} +</pre> +</div> + +<p>These descriptors are used to define members of an + enumeration <a href="#format_composite_type">composite type</a>, it + associates the name to the value.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_variables">Local variables</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_variables">llvm.dbg.variable.type</a> = type { + i32, ;; Tag (see below) + { }*, ;; Context + i8*, ;; Name + { }*, ;; Reference to compile unit where defined + i32, ;; Line number where defined + { }* ;; Type descriptor +} +</pre> +</div> + +<p>These descriptors are used to define variables local to a sub program. The + value of the tag depends on the usage of the variable:</p> + +<div class="doc_code"> +<pre> +DW_TAG_auto_variable = 256 +DW_TAG_arg_variable = 257 +DW_TAG_return_variable = 258 +</pre> +</div> + +<p>An auto variable is any variable declared in the body of the function. An + argument variable is any variable that appears as a formal argument to the + function. A return variable is used to track the result of a function and + has no source correspondent.</p> + +<p>The context is either the subprogram or block where the variable is defined. + Name the source variable name. Compile unit and line indicate where the + variable was defined. Type descriptor defines the declared type of the + variable.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="format_common_intrinsics">Debugger intrinsic functions</a> +</div> + +<div class="doc_text"> + +<p>LLVM uses several intrinsic functions (name prefixed with "llvm.dbg") to + provide debug information at various points in generated code.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_common_stoppoint">llvm.dbg.stoppoint</a> +</div> + +<div class="doc_text"> +<pre> + void %<a href="#format_common_stoppoint">llvm.dbg.stoppoint</a>( uint, uint, { }* ) +</pre> + +<p>This intrinsic is used to provide correspondence between the source file and + the generated code. The first argument is the line number (base 1), second + argument is the column number (0 if unknown) and the third argument the + source <tt>%<a href="#format_compile_units">llvm.dbg.compile_unit</a>*</tt> + cast to a <tt>{ }*</tt>. Code following a call to this intrinsic will + have been defined in close proximity of the line, column and file. This + information holds until the next call + to <tt>%<a href="#format_common_stoppoint">lvm.dbg.stoppoint</a></tt>.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_common_func_start">llvm.dbg.func.start</a> +</div> + +<div class="doc_text"> +<pre> + void %<a href="#format_common_func_start">llvm.dbg.func.start</a>( { }* ) +</pre> + +<p>This intrinsic is used to link the debug information + in <tt>%<a href="#format_subprograms">llvm.dbg.subprogram</a></tt> to the + function. It defines the beginning of the function's declarative region + (scope). It also implies a call to + %<tt><a href="#format_common_stoppoint">llvm.dbg.stoppoint</a></tt> which + defines a source line "stop point". The intrinsic should be called early in + the function after the all the alloca instructions. It should be paired off + with a closing + <tt>%<a href="#format_common_region_end">llvm.dbg.region.end</a></tt>. + The function's single argument is + the <tt>%<a href="#format_subprograms">llvm.dbg.subprogram.type</a></tt>.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_common_region_start">llvm.dbg.region.start</a> +</div> + +<div class="doc_text"> +<pre> + void %<a href="#format_common_region_start">llvm.dbg.region.start</a>( { }* ) +</pre> + +<p>This intrinsic is used to define the beginning of a declarative scope (ex. + block) for local language elements. It should be paired off with a closing + <tt>%<a href="#format_common_region_end">llvm.dbg.region.end</a></tt>. The + function's single argument is + the <tt>%<a href="#format_blocks">llvm.dbg.block</a></tt> which is + starting.</p> + + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_common_region_end">llvm.dbg.region.end</a> +</div> + +<div class="doc_text"> +<pre> + void %<a href="#format_common_region_end">llvm.dbg.region.end</a>( { }* ) +</pre> + +<p>This intrinsic is used to define the end of a declarative scope (ex. block) + for local language elements. It should be paired off with an + opening <tt>%<a href="#format_common_region_start">llvm.dbg.region.start</a></tt> + or <tt>%<a href="#format_common_func_start">llvm.dbg.func.start</a></tt>. + The function's single argument is either + the <tt>%<a href="#format_blocks">llvm.dbg.block</a></tt> or + the <tt>%<a href="#format_subprograms">llvm.dbg.subprogram.type</a></tt> + which is ending.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="format_common_declare">llvm.dbg.declare</a> +</div> + +<div class="doc_text"> +<pre> + void %<a href="#format_common_declare">llvm.dbg.declare</a>( { } *, { }* ) +</pre> + +<p>This intrinsic provides information about a local element (ex. variable.) The + first argument is the alloca for the variable, cast to a <tt>{ }*</tt>. The + second argument is + the <tt>%<a href="#format_variables">llvm.dbg.variable</a></tt> containing + the description of the variable, also cast to a <tt>{ }*</tt>.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="format_common_stoppoints"> + Representing stopping points in the source program + </a> +</div> + +<div class="doc_text"> + +<p>LLVM debugger "stop points" are a key part of the debugging representation + that allows the LLVM to maintain simple semantics + for <a href="#debugopt">debugging optimized code</a>. The basic idea is that + the front-end inserts calls to + the <a href="#format_common_stoppoint">%<tt>llvm.dbg.stoppoint</tt></a> + intrinsic function at every point in the program where a debugger should be + able to inspect the program (these correspond to places a debugger stops when + you "<tt>step</tt>" through it). The front-end can choose to place these as + fine-grained as it would like (for example, before every subexpression + evaluated), but it is recommended to only put them after every source + statement that includes executable code.</p> + +<p>Using calls to this intrinsic function to demark legal points for the + debugger to inspect the program automatically disables any optimizations that + could potentially confuse debugging information. To + non-debug-information-aware transformations, these calls simply look like + calls to an external function, which they must assume to do anything + (including reading or writing to any part of reachable memory). On the other + hand, it does not impact many optimizations, such as code motion of + non-trapping instructions, nor does it impact optimization of subexpressions, + code duplication transformations, or basic-block reordering + transformations.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="format_common_lifetime">Object lifetimes and scoping</a> +</div> + +<div class="doc_text"> +<p>In many languages, the local variables in functions can have their lifetime + or scope limited to a subset of a function. In the C family of languages, + for example, variables are only live (readable and writable) within the + source block that they are defined in. In functional languages, values are + only readable after they have been defined. Though this is a very obvious + concept, it is also non-trivial to model in LLVM, because it has no notion of + scoping in this sense, and does not want to be tied to a language's scoping + rules.</p> + +<p>In order to handle this, the LLVM debug format uses the notion of "regions" + of a function, delineated by calls to intrinsic functions. These intrinsic + functions define new regions of the program and indicate when the region + lifetime expires. Consider the following C fragment, for example:</p> + +<div class="doc_code"> +<pre> +1. void foo() { +2. int X = ...; +3. int Y = ...; +4. { +5. int Z = ...; +6. ... +7. } +8. ... +9. } +</pre> +</div> + +<p>Compiled to LLVM, this function would be represented like this:</p> + +<div class="doc_code"> +<pre> +void %foo() { +entry: + %X = alloca int + %Y = alloca int + %Z = alloca int + + ... + + 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 ) + + 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 ) + + call void @<a href="#format_common_declare">llvm.dbg.declare</a>({}* %X, ...) + call void @<a href="#format_common_declare">llvm.dbg.declare</a>({}* %Y, ...) + + <i>;; Evaluate expression on line 2, assigning to X.</i> + + 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 ) + + <i>;; Evaluate expression on line 3, assigning to Y.</i> + + call void @<a href="#format_common_stoppoint">llvm.region.start</a>() + 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 ) + call void @<a href="#format_common_declare">llvm.dbg.declare</a>({}* %X, ...) + + <i>;; Evaluate expression on line 5, assigning to Z.</i> + + 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 ) + call void @<a href="#format_common_region_end">llvm.region.end</a>() + + 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 ) + + call void @<a href="#format_common_region_end">llvm.region.end</a>() + + ret void +} +</pre> +</div> + +<p>This example illustrates a few important details about the LLVM debugging + information. In particular, it shows how the various intrinsics are applied + together to allow a debugger to analyze the relationship between statements, + variable definitions, and the code used to implement the function.</p> + +<p>The first + intrinsic <tt>%<a href="#format_common_func_start">llvm.dbg.func.start</a></tt> + provides a link with the <a href="#format_subprograms">subprogram + descriptor</a> containing the details of this function. This call also + defines the beginning of the function region, bounded by + the <tt>%<a href="#format_common_region_end">llvm.region.end</a></tt> at the + end of the function. This region is used to bracket the lifetime of + variables declared within. For a function, this outer region defines a new + stack frame whose lifetime ends when the region is ended.</p> + +<p>It is possible to define inner regions for short term variables by using the + %<a href="#format_common_stoppoint"><tt>llvm.region.start</tt></a> + and <a href="#format_common_region_end"><tt>%llvm.region.end</tt></a> to + bound a region. The inner region in this example would be for the block + containing the declaration of Z.</p> + +<p>Using regions to represent the boundaries of source-level functions allow + LLVM interprocedural optimizations to arbitrarily modify LLVM functions + without having to worry about breaking mapping information between the LLVM + code and the and source-level program. In particular, the inliner requires + no modification to support inlining with debugging information: there is no + explicit correlation drawn between LLVM functions and their source-level + counterparts (note however, that if the inliner inlines all instances of a + non-strong-linkage function into its caller that it will not be possible for + the user to manually invoke the inlined function from a debugger).</p> + +<p>Once the function has been defined, + the <a href="#format_common_stoppoint"><tt>stopping point</tt></a> + corresponding to line #2 (column #2) of the function is encountered. At this + point in the function, <b>no</b> local variables are live. As lines 2 and 3 + of the example are executed, their variable definitions are introduced into + the program using + %<a href="#format_common_declare"><tt>llvm.dbg.declare</tt></a>, without the + need to specify a new region. These variables do not require new regions to + be introduced because they go out of scope at the same point in the program: + line 9.</p> + +<p>In contrast, the <tt>Z</tt> variable goes out of scope at a different time, + on line 7. For this reason, it is defined within the inner region, which + kills the availability of <tt>Z</tt> before the code for line 8 is executed. + In this way, regions can support arbitrary source-language scoping rules, as + long as they can only be nested (ie, one scope cannot partially overlap with + a part of another scope).</p> + +<p>It is worth noting that this scoping mechanism is used to control scoping of + all declarations, not just variable declarations. For example, the scope of + a C++ using declaration is controlled with this and could change how name + lookup is performed.</p> + +</div> + +<!-- *********************************************************************** --> +<div class="doc_section"> + <a name="ccxx_frontend">C/C++ front-end specific debug information</a> +</div> +<!-- *********************************************************************** --> + +<div class="doc_text"> + +<p>The C and C++ front-ends represent information about the program in a format + that is effectively identical + to <a href="http://www.eagercon.com/dwarf/dwarf3std.htm">DWARF 3.0</a> in + terms of information content. This allows code generators to trivially + support native debuggers by generating standard dwarf information, and + contains enough information for non-dwarf targets to translate it as + needed.</p> + +<p>This section describes the forms used to represent C and C++ programs. Other + languages could pattern themselves after this (which itself is tuned to + representing programs in the same way that DWARF 3 does), or they could + choose to provide completely different forms if they don't fit into the DWARF + model. As support for debugging information gets added to the various LLVM + source-language front-ends, the information used should be documented + here.</p> + +<p>The following sections provide examples of various C/C++ constructs and the + debug information that would best describe those constructs.</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="ccxx_compile_units">C/C++ source file information</a> +</div> + +<div class="doc_text"> + +<p>Given the source files <tt>MySource.cpp</tt> and <tt>MyHeader.h</tt> located + in the directory <tt>/Users/mine/sources</tt>, the following code:</p> + +<div class="doc_code"> +<pre> +#include "MyHeader.h" + +int main(int argc, char *argv[]) { + return 0; +} +</pre> +</div> + +<p>a C/C++ front-end would generate the following descriptors:</p> + +<div class="doc_code"> +<pre> +... +;; +;; Define types used. In this case we need one for compile unit anchors and one +;; for compile units. +;; +%<a href="#format_anchors">llvm.dbg.anchor.type</a> = type { uint, uint } +%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> = type { uint, { }*, uint, uint, i8*, i8*, i8* } +... +;; +;; Define the anchor for compile units. Note that the second field of the +;; anchor is 17, which is the same as the tag for compile units +;; (17 = DW_TAG_compile_unit.) +;; +%<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" + +;; +;; Define the compile unit for the source file "/Users/mine/sources/MySource.cpp". +;; +%<a href="#format_compile_units">llvm.dbg.compile_unit1</a> = internal constant %<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> { + uint add(uint 17, uint 262144), + { }* cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_units</a> to { }*), + uint 1, + uint 1, + i8* getelementptr ([13 x i8]* %str1, i32 0, i32 0), + i8* getelementptr ([21 x i8]* %str2, i32 0, i32 0), + i8* getelementptr ([33 x i8]* %str3, i32 0, i32 0) }, section "llvm.metadata" + +;; +;; Define the compile unit for the header file "/Users/mine/sources/MyHeader.h". +;; +%<a href="#format_compile_units">llvm.dbg.compile_unit2</a> = internal constant %<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> { + uint add(uint 17, uint 262144), + { }* cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_units</a> to { }*), + uint 1, + uint 1, + i8* getelementptr ([11 x i8]* %str4, int 0, int 0), + i8* getelementptr ([21 x i8]* %str2, int 0, int 0), + i8* getelementptr ([33 x i8]* %str3, int 0, int 0) }, section "llvm.metadata" + +;; +;; Define each of the strings used in the compile units. +;; +%str1 = internal constant [13 x i8] c"MySource.cpp\00", section "llvm.metadata"; +%str2 = internal constant [21 x i8] c"/Users/mine/sources/\00", section "llvm.metadata"; +%str3 = internal constant [33 x i8] c"4.0.1 LLVM (LLVM research group)\00", section "llvm.metadata"; +%str4 = internal constant [11 x i8] c"MyHeader.h\00", section "llvm.metadata"; +... +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="ccxx_global_variable">C/C++ global variable information</a> +</div> + +<div class="doc_text"> + +<p>Given an integer global variable declared as follows:</p> + +<div class="doc_code"> +<pre> +int MyGlobal = 100; +</pre> +</div> + +<p>a C/C++ front-end would generate the following descriptors:</p> + +<div class="doc_code"> +<pre> +;; +;; Define types used. One for global variable anchors, one for the global +;; variable descriptor, one for the global's basic type and one for the global's +;; compile unit. +;; +%<a href="#format_anchors">llvm.dbg.anchor.type</a> = type { uint, uint } +%<a href="#format_global_variables">llvm.dbg.global_variable.type</a> = type { uint, { }*, { }*, i8*, { }*, uint, { }*, bool, bool, { }*, uint } +%<a href="#format_basic_type">llvm.dbg.basictype.type</a> = type { uint, { }*, i8*, { }*, int, uint, uint, uint, uint } +%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> = ... +... +;; +;; Define the global itself. +;; +%MyGlobal = global int 100 +... +;; +;; Define the anchor for global variables. Note that the second field of the +;; anchor is 52, which is the same as the tag for global variables +;; (52 = DW_TAG_variable.) +;; +%<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" + +;; +;; Define the global variable descriptor. Note the reference to the global +;; variable anchor and the global variable itself. +;; +%<a href="#format_global_variables">llvm.dbg.global_variable</a> = internal constant %<a href="#format_global_variables">llvm.dbg.global_variable.type</a> { + uint add(uint 52, uint 262144), + { }* cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_global_variables">llvm.dbg.global_variables</a> to { }*), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([9 x i8]* %str1, int 0, int 0), + i8* getelementptr ([1 x i8]* %str2, int 0, int 0), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + uint 1, + { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype</a> to { }*), + bool false, + bool true, + { }* cast (int* %MyGlobal to { }*) }, section "llvm.metadata" + +;; +;; Define the basic type of 32 bit signed integer. Note that since int is an +;; intrinsic type the source file is NULL and line 0. +;; +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([4 x i8]* %str3, int 0, int 0), + { }* null, + int 0, + uint 32, + uint 32, + uint 0, + uint 5 }, section "llvm.metadata" + +;; +;; Define the names of the global variable and basic type. +;; +%str1 = internal constant [9 x i8] c"MyGlobal\00", section "llvm.metadata" +%str2 = internal constant [1 x i8] c"\00", section "llvm.metadata" +%str3 = internal constant [4 x i8] c"int\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="ccxx_subprogram">C/C++ function information</a> +</div> + +<div class="doc_text"> + +<p>Given a function declared as follows:</p> + +<div class="doc_code"> +<pre> +int main(int argc, char *argv[]) { + return 0; +} +</pre> +</div> + +<p>a C/C++ front-end would generate the following descriptors:</p> + +<div class="doc_code"> +<pre> +;; +;; Define types used. One for subprogram anchors, one for the subprogram +;; descriptor, one for the global's basic type and one for the subprogram's +;; compile unit. +;; +%<a href="#format_subprograms">llvm.dbg.subprogram.type</a> = type { uint, { }*, { }*, i8*, { }*, bool, bool } +%<a href="#format_anchors">llvm.dbg.anchor.type</a> = type { uint, uint } +%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a> = ... + +;; +;; Define the anchor for subprograms. Note that the second field of the +;; anchor is 46, which is the same as the tag for subprograms +;; (46 = DW_TAG_subprogram.) +;; +%<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" + +;; +;; Define the descriptor for the subprogram. TODO - more details. +;; +%<a href="#format_subprograms">llvm.dbg.subprogram</a> = internal constant %<a href="#format_subprograms">llvm.dbg.subprogram.type</a> { + uint add(uint 46, uint 262144), + { }* cast (%<a href="#format_anchors">llvm.dbg.anchor.type</a>* %<a href="#format_subprograms">llvm.dbg.subprograms</a> to { }*), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([5 x i8]* %str1, int 0, int 0), + i8* getelementptr ([1 x i8]* %str2, int 0, int 0), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + uint 1, + { }* null, + bool false, + bool true }, section "llvm.metadata" + +;; +;; Define the name of the subprogram. +;; +%str1 = internal constant [5 x i8] c"main\00", section "llvm.metadata" +%str2 = internal constant [1 x i8] c"\00", section "llvm.metadata" + +;; +;; Define the subprogram itself. +;; +int %main(int %argc, i8** %argv) { +... +} +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="ccxx_basic_types">C/C++ basic types</a> +</div> + +<div class="doc_text"> + +<p>The following are the basic type descriptors for C/C++ core types:</p> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_type_bool">bool</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([5 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 32, + uint 32, + uint 0, + uint 2 }, section "llvm.metadata" +%str1 = internal constant [5 x i8] c"bool\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_char">char</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([5 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 8, + uint 8, + uint 0, + uint 6 }, section "llvm.metadata" +%str1 = internal constant [5 x i8] c"char\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_unsigned_char">unsigned char</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([14 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 8, + uint 8, + uint 0, + uint 8 }, section "llvm.metadata" +%str1 = internal constant [14 x i8] c"unsigned char\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_short">short</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([10 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 16, + uint 16, + uint 0, + uint 5 }, section "llvm.metadata" +%str1 = internal constant [10 x i8] c"short int\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_unsigned_short">unsigned short</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([19 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 16, + uint 16, + uint 0, + uint 7 }, section "llvm.metadata" +%str1 = internal constant [19 x i8] c"short unsigned int\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_int">int</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([4 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 32, + uint 32, + uint 0, + uint 5 }, section "llvm.metadata" +%str1 = internal constant [4 x i8] c"int\00", section "llvm.metadata" +</pre></div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_unsigned_int">unsigned int</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([13 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 32, + uint 32, + uint 0, + uint 7 }, section "llvm.metadata" +%str1 = internal constant [13 x i8] c"unsigned int\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_long_long">long long</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([14 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 64, + uint 64, + uint 0, + uint 5 }, section "llvm.metadata" +%str1 = internal constant [14 x i8] c"long long int\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_unsigned_long_long">unsigned long long</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([23 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 64, + uint 64, + uint 0, + uint 7 }, section "llvm.metadata" +%str1 = internal constant [23 x 8] c"long long unsigned int\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_float">float</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([6 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 32, + uint 32, + uint 0, + uint 4 }, section "llvm.metadata" +%str1 = internal constant [6 x i8] c"float\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsubsection"> + <a name="ccxx_basic_double">double</a> +</div> + +<div class="doc_text"> + +<div class="doc_code"> +<pre> +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + 8* getelementptr ([7 x 8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 64, + uint 64, + uint 0, + uint 4 }, section "llvm.metadata" +%str1 = internal constant [7 x 8] c"double\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="ccxx_derived_types">C/C++ derived types</a> +</div> + +<div class="doc_text"> + +<p>Given the following as an example of C/C++ derived type:</p> + +<div class="doc_code"> +<pre> +typedef const int *IntPtr; +</pre> +</div> + +<p>a C/C++ front-end would generate the following descriptors:</p> + +<div class="doc_code"> +<pre> +;; +;; Define the typedef "IntPtr". +;; +%<a href="#format_derived_type">llvm.dbg.derivedtype1</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> { + uint add(uint 22, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([7 x 8]* %str1, int 0, int 0), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + int 1, + uint 0, + uint 0, + uint 0, + { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype2</a> to { }*) }, section "llvm.metadata" +%str1 = internal constant [7 x 8] c"IntPtr\00", section "llvm.metadata" + +;; +;; Define the pointer type. +;; +%<a href="#format_derived_type">llvm.dbg.derivedtype2</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> { + uint add(uint 15, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* null, + { }* null, + int 0, + uint 32, + uint 32, + uint 0, + { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype3</a> to { }*) }, section "llvm.metadata" + +;; +;; Define the const type. +;; +%<a href="#format_derived_type">llvm.dbg.derivedtype3</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> { + uint add(uint 38, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* null, + { }* null, + int 0, + uint 0, + uint 0, + uint 0, + { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype1</a> to { }*) }, section "llvm.metadata" + +;; +;; Define the int type. +;; +%<a href="#format_basic_type">llvm.dbg.basictype1</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + 8* getelementptr ([4 x 8]* %str2, int 0, int 0), + { }* null, + int 0, + uint 32, + uint 32, + uint 0, + uint 5 }, section "llvm.metadata" +%str2 = internal constant [4 x 8] c"int\00", section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="ccxx_composite_types">C/C++ struct/union types</a> +</div> + +<div class="doc_text"> + +<p>Given the following as an example of C/C++ struct type:</p> + +<div class="doc_code"> +<pre> +struct Color { + unsigned Red; + unsigned Green; + unsigned Blue; +}; +</pre> +</div> + +<p>a C/C++ front-end would generate the following descriptors:</p> + +<div class="doc_code"> +<pre> +;; +;; Define basic type for unsigned int. +;; +%<a href="#format_basic_type">llvm.dbg.basictype</a> = internal constant %<a href="#format_basic_type">llvm.dbg.basictype.type</a> { + uint add(uint 36, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([13 x i8]* %str1, int 0, int 0), + { }* null, + int 0, + uint 32, + uint 32, + uint 0, + uint 7 }, section "llvm.metadata" +%str1 = internal constant [13 x i8] c"unsigned int\00", section "llvm.metadata" + +;; +;; Define composite type for struct Color. +;; +%<a href="#format_composite_type">llvm.dbg.compositetype</a> = internal constant %<a href="#format_composite_type">llvm.dbg.compositetype.type</a> { + uint add(uint 19, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([6 x i8]* %str2, int 0, int 0), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + int 1, + uint 96, + uint 32, + uint 0, + { }* null, + { }* cast ([3 x { }*]* %llvm.dbg.array to { }*) }, section "llvm.metadata" +%str2 = internal constant [6 x i8] c"Color\00", section "llvm.metadata" + +;; +;; Define the Red field. +;; +%<a href="#format_derived_type">llvm.dbg.derivedtype1</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> { + uint add(uint 13, uint 262144), + { }* null, + i8* getelementptr ([4 x i8]* %str3, int 0, int 0), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + int 2, + uint 32, + uint 32, + uint 0, + { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype</a> to { }*) }, section "llvm.metadata" +%str3 = internal constant [4 x i8] c"Red\00", section "llvm.metadata" + +;; +;; Define the Green field. +;; +%<a href="#format_derived_type">llvm.dbg.derivedtype2</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> { + uint add(uint 13, uint 262144), + { }* null, + i8* getelementptr ([6 x i8]* %str4, int 0, int 0), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + int 3, + uint 32, + uint 32, + uint 32, + { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype</a> to { }*) }, section "llvm.metadata" +%str4 = internal constant [6 x i8] c"Green\00", section "llvm.metadata" + +;; +;; Define the Blue field. +;; +%<a href="#format_derived_type">llvm.dbg.derivedtype3</a> = internal constant %<a href="#format_derived_type">llvm.dbg.derivedtype.type</a> { + uint add(uint 13, uint 262144), + { }* null, + i8* getelementptr ([5 x i8]* %str5, int 0, int 0), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + int 4, + uint 32, + uint 32, + uint 64, + { }* cast (%<a href="#format_basic_type">llvm.dbg.basictype.type</a>* %<a href="#format_basic_type">llvm.dbg.basictype</a> to { }*) }, section "llvm.metadata" +%str5 = internal constant [5 x 8] c"Blue\00", section "llvm.metadata" + +;; +;; Define the array of fields used by the composite type Color. +;; +%llvm.dbg.array = internal constant [3 x { }*] [ + { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype1</a> to { }*), + { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype2</a> to { }*), + { }* cast (%<a href="#format_derived_type">llvm.dbg.derivedtype.type</a>* %<a href="#format_derived_type">llvm.dbg.derivedtype3</a> to { }*) ], section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- ======================================================================= --> +<div class="doc_subsection"> + <a name="ccxx_enumeration_types">C/C++ enumeration types</a> +</div> + +<div class="doc_text"> + +<p>Given the following as an example of C/C++ enumeration type:</p> + +<div class="doc_code"> +<pre> +enum Trees { + Spruce = 100, + Oak = 200, + Maple = 300 +}; +</pre> +</div> + +<p>a C/C++ front-end would generate the following descriptors:</p> + +<div class="doc_code"> +<pre> +;; +;; Define composite type for enum Trees +;; +%<a href="#format_composite_type">llvm.dbg.compositetype</a> = internal constant %<a href="#format_composite_type">llvm.dbg.compositetype.type</a> { + uint add(uint 4, uint 262144), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + i8* getelementptr ([6 x i8]* %str1, int 0, int 0), + { }* cast (%<a href="#format_compile_units">llvm.dbg.compile_unit.type</a>* %<a href="#format_compile_units">llvm.dbg.compile_unit</a> to { }*), + int 1, + uint 32, + uint 32, + uint 0, + { }* null, + { }* cast ([3 x { }*]* %llvm.dbg.array to { }*) }, section "llvm.metadata" +%str1 = internal constant [6 x i8] c"Trees\00", section "llvm.metadata" + +;; +;; Define Spruce enumerator. +;; +%<a href="#format_enumeration">llvm.dbg.enumerator1</a> = internal constant %<a href="#format_enumeration">llvm.dbg.enumerator.type</a> { + uint add(uint 40, uint 262144), + i8* getelementptr ([7 x i8]* %str2, int 0, int 0), + int 100 }, section "llvm.metadata" +%str2 = internal constant [7 x i8] c"Spruce\00", section "llvm.metadata" + +;; +;; Define Oak enumerator. +;; +%<a href="#format_enumeration">llvm.dbg.enumerator2</a> = internal constant %<a href="#format_enumeration">llvm.dbg.enumerator.type</a> { + uint add(uint 40, uint 262144), + i8* getelementptr ([4 x i8]* %str3, int 0, int 0), + int 200 }, section "llvm.metadata" +%str3 = internal constant [4 x i8] c"Oak\00", section "llvm.metadata" + +;; +;; Define Maple enumerator. +;; +%<a href="#format_enumeration">llvm.dbg.enumerator3</a> = internal constant %<a href="#format_enumeration">llvm.dbg.enumerator.type</a> { + uint add(uint 40, uint 262144), + i8* getelementptr ([6 x i8]* %str4, int 0, int 0), + int 300 }, section "llvm.metadata" +%str4 = internal constant [6 x i8] c"Maple\00", section "llvm.metadata" + +;; +;; Define the array of enumerators used by composite type Trees. +;; +%llvm.dbg.array = internal constant [3 x { }*] [ + { }* cast (%<a href="#format_enumeration">llvm.dbg.enumerator.type</a>* %<a href="#format_enumeration">llvm.dbg.enumerator1</a> to { }*), + { }* cast (%<a href="#format_enumeration">llvm.dbg.enumerator.type</a>* %<a href="#format_enumeration">llvm.dbg.enumerator2</a> to { }*), + { }* cast (%<a href="#format_enumeration">llvm.dbg.enumerator.type</a>* %<a href="#format_enumeration">llvm.dbg.enumerator3</a> to { }*) ], section "llvm.metadata" +</pre> +</div> + +</div> + +<!-- *********************************************************************** --> + +<hr> +<address> + <a href="http://jigsaw.w3.org/css-validator/check/referer"><img + src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a> + <a href="http://validator.w3.org/check/referer"><img + src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a> + + <a href="mailto:sabre@nondot.org">Chris Lattner</a><br> + <a href="http://llvm.org">LLVM Compiler Infrastructure</a><br> + Last modified: $Date: 2009-05-29 19:08:57 +0200 (Fri, 29 May 2009) $ +</address> + +</body> +</html> |
