| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 1 | <?xml version="1.0" encoding="utf-8" ?> | 
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| Reid Spencer | b1254a1 | 2004-08-09 03:08:29 +0000 | [diff] [blame] | 4 | <head> | 
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| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 7 | <title>Customizing LLVMC: Reference Manual</title> | 
| Mikhail Glushenkov | 8cc8288 | 2008-12-13 17:50:58 +0000 | [diff] [blame] | 8 | <link rel="stylesheet" href="llvm.css" type="text/css" /> | 
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| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 11 | <div class="document" id="customizing-llvmc-reference-manual"> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 12 | <h1 class="title">Customizing LLVMC: Reference Manual</h1> | 
| Mikhail Glushenkov | 23f522a | 2008-12-13 17:51:47 +0000 | [diff] [blame^] | 13 | <!-- This file was automatically generated by rst2html. | 
 | 14 | Please do not edit directly! | 
 | 15 | The ReST source lives in the directory 'tools/llvmc/doc'. --> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 16 | <div class="contents topic"> | 
 | 17 | <p class="topic-title first"><a id="contents" name="contents">Contents</a></p> | 
 | 18 | <ul class="simple"> | 
 | 19 | <li><a class="reference" href="#introduction" id="id4" name="id4">Introduction</a></li> | 
 | 20 | <li><a class="reference" href="#compiling-with-llvmc" id="id5" name="id5">Compiling with LLVMC</a></li> | 
 | 21 | <li><a class="reference" href="#predefined-options" id="id6" name="id6">Predefined options</a></li> | 
 | 22 | <li><a class="reference" href="#compiling-llvmc-plugins" id="id7" name="id7">Compiling LLVMC plugins</a></li> | 
 | 23 | <li><a class="reference" href="#customizing-llvmc-the-compilation-graph" id="id8" name="id8">Customizing LLVMC: the compilation graph</a></li> | 
 | 24 | <li><a class="reference" href="#describing-options" id="id9" name="id9">Describing options</a><ul> | 
 | 25 | <li><a class="reference" href="#external-options" id="id10" name="id10">External options</a></li> | 
 | 26 | </ul> | 
 | 27 | </li> | 
 | 28 | <li><a class="reference" href="#conditional-evaluation" id="id11" name="id11">Conditional evaluation</a></li> | 
 | 29 | <li><a class="reference" href="#writing-a-tool-description" id="id12" name="id12">Writing a tool description</a><ul> | 
 | 30 | <li><a class="reference" href="#actions" id="id13" name="id13">Actions</a></li> | 
 | 31 | </ul> | 
 | 32 | </li> | 
 | 33 | <li><a class="reference" href="#language-map" id="id14" name="id14">Language map</a></li> | 
 | 34 | <li><a class="reference" href="#more-advanced-topics" id="id15" name="id15">More advanced topics</a><ul> | 
 | 35 | <li><a class="reference" href="#hooks-and-environment-variables" id="id16" name="id16">Hooks and environment variables</a></li> | 
 | 36 | <li><a class="reference" href="#how-plugins-are-loaded" id="id17" name="id17">How plugins are loaded</a></li> | 
 | 37 | <li><a class="reference" href="#debugging" id="id18" name="id18">Debugging</a></li> | 
 | 38 | </ul> | 
 | 39 | </li> | 
 | 40 | </ul> | 
 | 41 | </div> | 
 | 42 | <div class="doc_author"> | 
 | 43 | <p>Written by <a href="mailto:foldr@codedgers.com">Mikhail Glushenkov</a></p> | 
 | 44 | </div><div class="section"> | 
 | 45 | <h1><a class="toc-backref" href="#id4" id="introduction" name="introduction">Introduction</a></h1> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 46 | <p>LLVMC is a generic compiler driver, designed to be customizable and | 
 | 47 | extensible. It plays the same role for LLVM as the <tt class="docutils literal"><span class="pre">gcc</span></tt> program | 
 | 48 | does for GCC - LLVMC's job is essentially to transform a set of input | 
 | 49 | files into a set of targets depending on configuration rules and user | 
 | 50 | options. What makes LLVMC different is that these transformation rules | 
 | 51 | are completely customizable - in fact, LLVMC knows nothing about the | 
 | 52 | specifics of transformation (even the command-line options are mostly | 
 | 53 | not hard-coded) and regards the transformation structure as an | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 54 | abstract graph. The structure of this graph is completely determined | 
 | 55 | by plugins, which can be either statically or dynamically linked. This | 
 | 56 | makes it possible to easily adapt LLVMC for other purposes - for | 
 | 57 | example, as a build tool for game resources.</p> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 58 | <p>Because LLVMC employs <a class="reference" href="http://llvm.cs.uiuc.edu/docs/TableGenFundamentals.html">TableGen</a> as its configuration language, you | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 59 | need to be familiar with it to customize LLVMC.</p> | 
| Reid Spencer | b1254a1 | 2004-08-09 03:08:29 +0000 | [diff] [blame] | 60 | </div> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 61 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 62 | <h1><a class="toc-backref" href="#id5" id="compiling-with-llvmc" name="compiling-with-llvmc">Compiling with LLVMC</a></h1> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 63 | <p>LLVMC tries hard to be as compatible with <tt class="docutils literal"><span class="pre">gcc</span></tt> as possible, | 
 | 64 | although there are some small differences. Most of the time, however, | 
 | 65 | you shouldn't be able to notice them:</p> | 
 | 66 | <pre class="literal-block"> | 
 | 67 | $ # This works as expected: | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 68 | $ llvmc -O3 -Wall hello.cpp | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 69 | $ ./a.out | 
 | 70 | hello | 
 | 71 | </pre> | 
 | 72 | <p>One nice feature of LLVMC is that one doesn't have to distinguish | 
 | 73 | between different compilers for different languages (think <tt class="docutils literal"><span class="pre">g++</span></tt> and | 
 | 74 | <tt class="docutils literal"><span class="pre">gcc</span></tt>) - the right toolchain is chosen automatically based on input | 
 | 75 | language names (which are, in turn, determined from file | 
 | 76 | extensions). If you want to force files ending with ".c" to compile as | 
 | 77 | C++, use the <tt class="docutils literal"><span class="pre">-x</span></tt> option, just like you would do it with <tt class="docutils literal"><span class="pre">gcc</span></tt>:</p> | 
 | 78 | <pre class="literal-block"> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 79 | $ # hello.c is really a C++ file | 
 | 80 | $ llvmc -x c++ hello.c | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 81 | $ ./a.out | 
 | 82 | hello | 
 | 83 | </pre> | 
 | 84 | <p>On the other hand, when using LLVMC as a linker to combine several C++ | 
 | 85 | object files you should provide the <tt class="docutils literal"><span class="pre">--linker</span></tt> option since it's | 
 | 86 | impossible for LLVMC to choose the right linker in that case:</p> | 
 | 87 | <pre class="literal-block"> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 88 | $ llvmc -c hello.cpp | 
 | 89 | $ llvmc hello.o | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 90 | [A lot of link-time errors skipped] | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 91 | $ llvmc --linker=c++ hello.o | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 92 | $ ./a.out | 
 | 93 | hello | 
 | 94 | </pre> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 95 | <p>By default, LLVMC uses <tt class="docutils literal"><span class="pre">llvm-gcc</span></tt> to compile the source code. It is | 
 | 96 | also possible to choose the work-in-progress <tt class="docutils literal"><span class="pre">clang</span></tt> compiler with | 
 | 97 | the <tt class="docutils literal"><span class="pre">-clang</span></tt> option.</p> | 
| Reid Spencer | b1254a1 | 2004-08-09 03:08:29 +0000 | [diff] [blame] | 98 | </div> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 99 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 100 | <h1><a class="toc-backref" href="#id6" id="predefined-options" name="predefined-options">Predefined options</a></h1> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 101 | <p>LLVMC has some built-in options that can't be overridden in the | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 102 | configuration libraries:</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 103 | <ul class="simple"> | 
 | 104 | <li><tt class="docutils literal"><span class="pre">-o</span> <span class="pre">FILE</span></tt> - Output file name.</li> | 
 | 105 | <li><tt class="docutils literal"><span class="pre">-x</span> <span class="pre">LANGUAGE</span></tt> - Specify the language of the following input files | 
 | 106 | until the next -x option.</li> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 107 | <li><tt class="docutils literal"><span class="pre">-load</span> <span class="pre">PLUGIN_NAME</span></tt> - Load the specified plugin DLL. Example: | 
 | 108 | <tt class="docutils literal"><span class="pre">-load</span> <span class="pre">$LLVM_DIR/Release/lib/LLVMCSimple.so</span></tt>.</li> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 109 | <li><tt class="docutils literal"><span class="pre">-v</span></tt> - Enable verbose mode, i.e. print out all executed commands.</li> | 
 | 110 | <li><tt class="docutils literal"><span class="pre">--view-graph</span></tt> - Show a graphical representation of the compilation | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 111 | graph. Requires that you have <tt class="docutils literal"><span class="pre">dot</span></tt> and <tt class="docutils literal"><span class="pre">gv</span></tt> programs | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 112 | installed. Hidden option, useful for debugging.</li> | 
 | 113 | <li><tt class="docutils literal"><span class="pre">--write-graph</span></tt> - Write a <tt class="docutils literal"><span class="pre">compilation-graph.dot</span></tt> file in the | 
 | 114 | current directory with the compilation graph description in the | 
 | 115 | Graphviz format. Hidden option, useful for debugging.</li> | 
 | 116 | <li><tt class="docutils literal"><span class="pre">--save-temps</span></tt> - Write temporary files to the current directory | 
 | 117 | and do not delete them on exit. Hidden option, useful for debugging.</li> | 
 | 118 | <li><tt class="docutils literal"><span class="pre">--help</span></tt>, <tt class="docutils literal"><span class="pre">--help-hidden</span></tt>, <tt class="docutils literal"><span class="pre">--version</span></tt> - These options have | 
 | 119 | their standard meaning.</li> | 
 | 120 | </ul> | 
| Reid Spencer | b1254a1 | 2004-08-09 03:08:29 +0000 | [diff] [blame] | 121 | </div> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 122 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 123 | <h1><a class="toc-backref" href="#id7" id="compiling-llvmc-plugins" name="compiling-llvmc-plugins">Compiling LLVMC plugins</a></h1> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 124 | <p>It's easiest to start working on your own LLVMC plugin by copying the | 
 | 125 | skeleton project which lives under <tt class="docutils literal"><span class="pre">$LLVMC_DIR/plugins/Simple</span></tt>:</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 126 | <pre class="literal-block"> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 127 | $ cd $LLVMC_DIR/plugins | 
 | 128 | $ cp -r Simple MyPlugin | 
 | 129 | $ cd MyPlugin | 
 | 130 | $ ls | 
 | 131 | Makefile PluginMain.cpp Simple.td | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 132 | </pre> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 133 | <p>As you can see, our basic plugin consists of only two files (not | 
 | 134 | counting the build script). <tt class="docutils literal"><span class="pre">Simple.td</span></tt> contains TableGen | 
 | 135 | description of the compilation graph; its format is documented in the | 
 | 136 | following sections. <tt class="docutils literal"><span class="pre">PluginMain.cpp</span></tt> is just a helper file used to | 
 | 137 | compile the auto-generated C++ code produced from TableGen source. It | 
 | 138 | can also contain hook definitions (see <a class="reference" href="#hooks">below</a>).</p> | 
 | 139 | <p>The first thing that you should do is to change the <tt class="docutils literal"><span class="pre">LLVMC_PLUGIN</span></tt> | 
 | 140 | variable in the <tt class="docutils literal"><span class="pre">Makefile</span></tt> to avoid conflicts (since this variable | 
 | 141 | is used to name the resulting library):</p> | 
 | 142 | <pre class="literal-block"> | 
 | 143 | LLVMC_PLUGIN=MyPlugin | 
 | 144 | </pre> | 
 | 145 | <p>It is also a good idea to rename <tt class="docutils literal"><span class="pre">Simple.td</span></tt> to something less | 
 | 146 | generic:</p> | 
 | 147 | <pre class="literal-block"> | 
 | 148 | $ mv Simple.td MyPlugin.td | 
 | 149 | </pre> | 
 | 150 | <p>Note that the plugin source directory must be placed under | 
 | 151 | <tt class="docutils literal"><span class="pre">$LLVMC_DIR/plugins</span></tt> to make use of the existing build | 
 | 152 | infrastructure. To build a version of the LLVMC executable called | 
 | 153 | <tt class="docutils literal"><span class="pre">mydriver</span></tt> with your plugin compiled in, use the following command:</p> | 
 | 154 | <pre class="literal-block"> | 
 | 155 | $ cd $LLVMC_DIR | 
 | 156 | $ make BUILTIN_PLUGINS=MyPlugin DRIVER_NAME=mydriver | 
 | 157 | </pre> | 
 | 158 | <p>To build your plugin as a dynamic library, just <tt class="docutils literal"><span class="pre">cd</span></tt> to its source | 
 | 159 | directory and run <tt class="docutils literal"><span class="pre">make</span></tt>. The resulting file will be called | 
 | 160 | <tt class="docutils literal"><span class="pre">LLVMC$(LLVMC_PLUGIN).$(DLL_EXTENSION)</span></tt> (in our case, | 
 | 161 | <tt class="docutils literal"><span class="pre">LLVMCMyPlugin.so</span></tt>). This library can be then loaded in with the | 
 | 162 | <tt class="docutils literal"><span class="pre">-load</span></tt> option. Example:</p> | 
 | 163 | <pre class="literal-block"> | 
 | 164 | $ cd $LLVMC_DIR/plugins/Simple | 
 | 165 | $ make | 
 | 166 | $ llvmc -load $LLVM_DIR/Release/lib/LLVMCSimple.so | 
 | 167 | </pre> | 
 | 168 | <p>Sometimes, you will want a 'bare-bones' version of LLVMC that has no | 
 | 169 | built-in plugins. It can be compiled with the following command:</p> | 
 | 170 | <pre class="literal-block"> | 
 | 171 | $ cd $LLVMC_DIR | 
 | 172 | $ make BUILTIN_PLUGINS="" | 
 | 173 | </pre> | 
 | 174 | </div> | 
 | 175 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 176 | <h1><a class="toc-backref" href="#id8" id="customizing-llvmc-the-compilation-graph" name="customizing-llvmc-the-compilation-graph">Customizing LLVMC: the compilation graph</a></h1> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 177 | <p>Each TableGen configuration file should include the common | 
 | 178 | definitions:</p> | 
 | 179 | <pre class="literal-block"> | 
 | 180 | include "llvm/CompilerDriver/Common.td" | 
 | 181 | </pre> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 182 | <p>Internally, LLVMC stores information about possible source | 
 | 183 | transformations in form of a graph. Nodes in this graph represent | 
 | 184 | tools, and edges between two nodes represent a transformation path. A | 
 | 185 | special "root" node is used to mark entry points for the | 
 | 186 | transformations. LLVMC also assigns a weight to each edge (more on | 
 | 187 | this later) to choose between several alternative edges.</p> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 188 | <p>The definition of the compilation graph (see file | 
 | 189 | <tt class="docutils literal"><span class="pre">plugins/Base/Base.td</span></tt> for an example) is just a list of edges:</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 190 | <pre class="literal-block"> | 
 | 191 | def CompilationGraph : CompilationGraph<[ | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 192 |     Edge<"root", "llvm_gcc_c">, | 
 | 193 |     Edge<"root", "llvm_gcc_assembler">, | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 194 |     ... | 
 | 195 |  | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 196 |     Edge<"llvm_gcc_c", "llc">, | 
 | 197 |     Edge<"llvm_gcc_cpp", "llc">, | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 198 |     ... | 
 | 199 |  | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 200 |     OptionalEdge<"llvm_gcc_c", "opt", (case (switch_on "opt"), | 
 | 201 |                                       (inc_weight))>, | 
 | 202 |     OptionalEdge<"llvm_gcc_cpp", "opt", (case (switch_on "opt"), | 
 | 203 |                                               (inc_weight))>, | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 204 |     ... | 
 | 205 |  | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 206 |     OptionalEdge<"llvm_gcc_assembler", "llvm_gcc_cpp_linker", | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 207 |         (case (input_languages_contain "c++"), (inc_weight), | 
 | 208 |               (or (parameter_equals "linker", "g++"), | 
 | 209 |                   (parameter_equals "linker", "c++")), (inc_weight))>, | 
 | 210 |     ... | 
 | 211 |  | 
 | 212 |     ]>; | 
 | 213 | </pre> | 
 | 214 | <p>As you can see, the edges can be either default or optional, where | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 215 | optional edges are differentiated by an additional <tt class="docutils literal"><span class="pre">case</span></tt> expression | 
 | 216 | used to calculate the weight of this edge. Notice also that we refer | 
 | 217 | to tools via their names (as strings). This makes it possible to add | 
 | 218 | edges to an existing compilation graph in plugins without having to | 
 | 219 | know about all tool definitions used in the graph.</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 220 | <p>The default edges are assigned a weight of 1, and optional edges get a | 
 | 221 | weight of 0 + 2*N where N is the number of tests that evaluated to | 
 | 222 | true in the <tt class="docutils literal"><span class="pre">case</span></tt> expression. It is also possible to provide an | 
 | 223 | integer parameter to <tt class="docutils literal"><span class="pre">inc_weight</span></tt> and <tt class="docutils literal"><span class="pre">dec_weight</span></tt> - in this case, | 
 | 224 | the weight is increased (or decreased) by the provided value instead | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 225 | of the default 2. It is also possible to change the default weight of | 
 | 226 | an optional edge by using the <tt class="docutils literal"><span class="pre">default</span></tt> clause of the <tt class="docutils literal"><span class="pre">case</span></tt> | 
 | 227 | construct.</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 228 | <p>When passing an input file through the graph, LLVMC picks the edge | 
 | 229 | with the maximum weight. To avoid ambiguity, there should be only one | 
 | 230 | default edge between two nodes (with the exception of the root node, | 
 | 231 | which gets a special treatment - there you are allowed to specify one | 
 | 232 | default edge <em>per language</em>).</p> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 233 | <p>When multiple plugins are loaded, their compilation graphs are merged | 
 | 234 | together. Since multiple edges that have the same end nodes are not | 
 | 235 | allowed (i.e. the graph is not a multigraph), an edge defined in | 
 | 236 | several plugins will be replaced by the definition from the plugin | 
 | 237 | that was loaded last. Plugin load order can be controlled by using the | 
 | 238 | plugin priority feature described above.</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 239 | <p>To get a visual representation of the compilation graph (useful for | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 240 | debugging), run <tt class="docutils literal"><span class="pre">llvmc</span> <span class="pre">--view-graph</span></tt>. You will need <tt class="docutils literal"><span class="pre">dot</span></tt> and | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 241 | <tt class="docutils literal"><span class="pre">gsview</span></tt> installed for this to work properly.</p> | 
| Reid Spencer | b1254a1 | 2004-08-09 03:08:29 +0000 | [diff] [blame] | 242 | </div> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 243 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 244 | <h1><a class="toc-backref" href="#id9" id="describing-options" name="describing-options">Describing options</a></h1> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 245 | <p>Command-line options that the plugin supports are defined by using an | 
 | 246 | <tt class="docutils literal"><span class="pre">OptionList</span></tt>:</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 247 | <pre class="literal-block"> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 248 | def Options : OptionList<[ | 
 | 249 | (switch_option "E", (help "Help string")), | 
 | 250 | (alias_option "quiet", "q") | 
 | 251 | ... | 
 | 252 | ]>; | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 253 | </pre> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 254 | <p>As you can see, the option list is just a list of DAGs, where each DAG | 
 | 255 | is an option description consisting of the option name and some | 
 | 256 | properties. A plugin can define more than one option list (they are | 
 | 257 | all merged together in the end), which can be handy if one wants to | 
 | 258 | separate option groups syntactically.</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 259 | <ul> | 
 | 260 | <li><p class="first">Possible option types:</p> | 
 | 261 | <blockquote> | 
 | 262 | <ul class="simple"> | 
 | 263 | <li><tt class="docutils literal"><span class="pre">switch_option</span></tt> - a simple boolean switch, for example <tt class="docutils literal"><span class="pre">-time</span></tt>.</li> | 
 | 264 | <li><tt class="docutils literal"><span class="pre">parameter_option</span></tt> - option that takes an argument, for example | 
 | 265 | <tt class="docutils literal"><span class="pre">-std=c99</span></tt>;</li> | 
 | 266 | <li><tt class="docutils literal"><span class="pre">parameter_list_option</span></tt> - same as the above, but more than one | 
 | 267 | occurence of the option is allowed.</li> | 
 | 268 | <li><tt class="docutils literal"><span class="pre">prefix_option</span></tt> - same as the parameter_option, but the option name | 
 | 269 | and parameter value are not separated.</li> | 
 | 270 | <li><tt class="docutils literal"><span class="pre">prefix_list_option</span></tt> - same as the above, but more than one | 
 | 271 | occurence of the option is allowed; example: <tt class="docutils literal"><span class="pre">-lm</span> <span class="pre">-lpthread</span></tt>.</li> | 
 | 272 | <li><tt class="docutils literal"><span class="pre">alias_option</span></tt> - a special option type for creating | 
 | 273 | aliases. Unlike other option types, aliases are not allowed to | 
 | 274 | have any properties besides the aliased option name. Usage | 
 | 275 | example: <tt class="docutils literal"><span class="pre">(alias_option</span> <span class="pre">"preprocess",</span> <span class="pre">"E")</span></tt></li> | 
 | 276 | </ul> | 
 | 277 | </blockquote> | 
 | 278 | </li> | 
 | 279 | <li><p class="first">Possible option properties:</p> | 
 | 280 | <blockquote> | 
 | 281 | <ul class="simple"> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 282 | <li><tt class="docutils literal"><span class="pre">help</span></tt> - help string associated with this option. Used for | 
 | 283 | <tt class="docutils literal"><span class="pre">--help</span></tt> output.</li> | 
 | 284 | <li><tt class="docutils literal"><span class="pre">required</span></tt> - this option is obligatory.</li> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 285 | <li><tt class="docutils literal"><span class="pre">hidden</span></tt> - this option should not appear in the <tt class="docutils literal"><span class="pre">--help</span></tt> | 
 | 286 | output (but should appear in the <tt class="docutils literal"><span class="pre">--help-hidden</span></tt> output).</li> | 
 | 287 | <li><tt class="docutils literal"><span class="pre">really_hidden</span></tt> - the option should not appear in any help | 
 | 288 | output.</li> | 
 | 289 | <li><tt class="docutils literal"><span class="pre">extern</span></tt> - this option is defined in some other plugin, see below.</li> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 290 | </ul> | 
 | 291 | </blockquote> | 
 | 292 | </li> | 
 | 293 | </ul> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 294 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 295 | <h2><a class="toc-backref" href="#id10" id="external-options" name="external-options">External options</a></h2> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 296 | <p>Sometimes, when linking several plugins together, one plugin needs to | 
 | 297 | access options defined in some other plugin. Because of the way | 
 | 298 | options are implemented, such options should be marked as | 
 | 299 | <tt class="docutils literal"><span class="pre">extern</span></tt>. This is what the <tt class="docutils literal"><span class="pre">extern</span></tt> option property is | 
 | 300 | for. Example:</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 301 | <pre class="literal-block"> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 302 | ... | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 303 | (switch_option "E", (extern)) | 
 | 304 | ... | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 305 | </pre> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 306 | <p>See also the section on plugin <a class="reference" href="#priorities">priorities</a>.</p> | 
| Reid Spencer | b1254a1 | 2004-08-09 03:08:29 +0000 | [diff] [blame] | 307 | </div> | 
| Reid Spencer | b1254a1 | 2004-08-09 03:08:29 +0000 | [diff] [blame] | 308 | </div> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 309 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 310 | <h1><a class="toc-backref" href="#id11" id="conditional-evaluation" name="conditional-evaluation"><span id="case"></span>Conditional evaluation</a></h1> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 311 | <p>The 'case' construct is the main means by which programmability is | 
 | 312 | achieved in LLVMC. It can be used to calculate edge weights, program | 
 | 313 | actions and modify the shell commands to be executed. The 'case' | 
 | 314 | expression is designed after the similarly-named construct in | 
 | 315 | functional languages and takes the form <tt class="docutils literal"><span class="pre">(case</span> <span class="pre">(test_1),</span> <span class="pre">statement_1,</span> | 
 | 316 | <span class="pre">(test_2),</span> <span class="pre">statement_2,</span> <span class="pre">...</span> <span class="pre">(test_N),</span> <span class="pre">statement_N)</span></tt>. The statements | 
 | 317 | are evaluated only if the corresponding tests evaluate to true.</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 318 | <p>Examples:</p> | 
 | 319 | <pre class="literal-block"> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 320 | // Edge weight calculation | 
 | 321 |  | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 322 | // Increases edge weight by 5 if "-A" is provided on the | 
 | 323 | // command-line, and by 5 more if "-B" is also provided. | 
 | 324 | (case | 
 | 325 |     (switch_on "A"), (inc_weight 5), | 
 | 326 |     (switch_on "B"), (inc_weight 5)) | 
 | 327 |  | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 328 |  | 
 | 329 | // Tool command line specification | 
 | 330 |  | 
 | 331 | // Evaluates to "cmdline1" if the option "-A" is provided on the | 
 | 332 | // command line; to "cmdline2" if "-B" is provided; | 
 | 333 | // otherwise to "cmdline3". | 
 | 334 |  | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 335 | (case | 
 | 336 |     (switch_on "A"), "cmdline1", | 
 | 337 |     (switch_on "B"), "cmdline2", | 
 | 338 |     (default), "cmdline3") | 
 | 339 | </pre> | 
 | 340 | <p>Note the slight difference in 'case' expression handling in contexts | 
 | 341 | of edge weights and command line specification - in the second example | 
 | 342 | the value of the <tt class="docutils literal"><span class="pre">"B"</span></tt> switch is never checked when switch <tt class="docutils literal"><span class="pre">"A"</span></tt> is | 
 | 343 | enabled, and the whole expression always evaluates to <tt class="docutils literal"><span class="pre">"cmdline1"</span></tt> in | 
 | 344 | that case.</p> | 
 | 345 | <p>Case expressions can also be nested, i.e. the following is legal:</p> | 
 | 346 | <pre class="literal-block"> | 
 | 347 | (case (switch_on "E"), (case (switch_on "o"), ..., (default), ...) | 
 | 348 |       (default), ...) | 
 | 349 | </pre> | 
 | 350 | <p>You should, however, try to avoid doing that because it hurts | 
 | 351 | readability. It is usually better to split tool descriptions and/or | 
 | 352 | use TableGen inheritance instead.</p> | 
 | 353 | <ul class="simple"> | 
 | 354 | <li>Possible tests are:<ul> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 355 | <li><tt class="docutils literal"><span class="pre">switch_on</span></tt> - Returns true if a given command-line switch is | 
 | 356 | provided by the user. Example: <tt class="docutils literal"><span class="pre">(switch_on</span> <span class="pre">"opt")</span></tt>.</li> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 357 | <li><tt class="docutils literal"><span class="pre">parameter_equals</span></tt> - Returns true if a command-line parameter equals | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 358 | a given value. | 
 | 359 | Example: <tt class="docutils literal"><span class="pre">(parameter_equals</span> <span class="pre">"W",</span> <span class="pre">"all")</span></tt>.</li> | 
 | 360 | <li><tt class="docutils literal"><span class="pre">element_in_list</span></tt> - Returns true if a command-line parameter | 
 | 361 | list contains a given value. | 
 | 362 | Example: <tt class="docutils literal"><span class="pre">(parameter_in_list</span> <span class="pre">"l",</span> <span class="pre">"pthread")</span></tt>.</li> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 363 | <li><tt class="docutils literal"><span class="pre">input_languages_contain</span></tt> - Returns true if a given language | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 364 | belongs to the current input language set. | 
 | 365 | Example: <tt class="docutils literal"><span class="pre">(input_languages_contain</span> <span class="pre">"c++")</span></tt>.</li> | 
 | 366 | <li><tt class="docutils literal"><span class="pre">in_language</span></tt> - Evaluates to true if the input file language | 
 | 367 | equals to the argument. At the moment works only with <tt class="docutils literal"><span class="pre">cmd_line</span></tt> | 
 | 368 | and <tt class="docutils literal"><span class="pre">actions</span></tt> (on non-join nodes). | 
 | 369 | Example: <tt class="docutils literal"><span class="pre">(in_language</span> <span class="pre">"c++")</span></tt>.</li> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 370 | <li><tt class="docutils literal"><span class="pre">not_empty</span></tt> - Returns true if a given option (which should be | 
 | 371 | either a parameter or a parameter list) is set by the | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 372 | user. | 
 | 373 | Example: <tt class="docutils literal"><span class="pre">(not_empty</span> <span class="pre">"o")</span></tt>.</li> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 374 | <li><tt class="docutils literal"><span class="pre">default</span></tt> - Always evaluates to true. Should always be the last | 
 | 375 | test in the <tt class="docutils literal"><span class="pre">case</span></tt> expression.</li> | 
 | 376 | <li><tt class="docutils literal"><span class="pre">and</span></tt> - A standard logical combinator that returns true iff all | 
 | 377 | of its arguments return true. Used like this: <tt class="docutils literal"><span class="pre">(and</span> <span class="pre">(test1),</span> | 
 | 378 | <span class="pre">(test2),</span> <span class="pre">...</span> <span class="pre">(testN))</span></tt>. Nesting of <tt class="docutils literal"><span class="pre">and</span></tt> and <tt class="docutils literal"><span class="pre">or</span></tt> is allowed, | 
 | 379 | but not encouraged.</li> | 
 | 380 | <li><tt class="docutils literal"><span class="pre">or</span></tt> - Another logical combinator that returns true only if any | 
 | 381 | one of its arguments returns true. Example: <tt class="docutils literal"><span class="pre">(or</span> <span class="pre">(test1),</span> | 
 | 382 | <span class="pre">(test2),</span> <span class="pre">...</span> <span class="pre">(testN))</span></tt>.</li> | 
 | 383 | </ul> | 
 | 384 | </li> | 
 | 385 | </ul> | 
| Reid Spencer | 46d2192 | 2004-08-22 18:06:59 +0000 | [diff] [blame] | 386 | </div> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 387 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 388 | <h1><a class="toc-backref" href="#id12" id="writing-a-tool-description" name="writing-a-tool-description">Writing a tool description</a></h1> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 389 | <p>As was said earlier, nodes in the compilation graph represent tools, | 
 | 390 | which are described separately. A tool definition looks like this | 
 | 391 | (taken from the <tt class="docutils literal"><span class="pre">include/llvm/CompilerDriver/Tools.td</span></tt> file):</p> | 
 | 392 | <pre class="literal-block"> | 
 | 393 | def llvm_gcc_cpp : Tool<[ | 
 | 394 |     (in_language "c++"), | 
 | 395 |     (out_language "llvm-assembler"), | 
 | 396 |     (output_suffix "bc"), | 
 | 397 |     (cmd_line "llvm-g++ -c $INFILE -o $OUTFILE -emit-llvm"), | 
 | 398 |     (sink) | 
 | 399 |     ]>; | 
 | 400 | </pre> | 
 | 401 | <p>This defines a new tool called <tt class="docutils literal"><span class="pre">llvm_gcc_cpp</span></tt>, which is an alias for | 
 | 402 | <tt class="docutils literal"><span class="pre">llvm-g++</span></tt>. As you can see, a tool definition is just a list of | 
 | 403 | properties; most of them should be self-explanatory. The <tt class="docutils literal"><span class="pre">sink</span></tt> | 
 | 404 | property means that this tool should be passed all command-line | 
 | 405 | options that aren't mentioned in the option list.</p> | 
 | 406 | <p>The complete list of all currently implemented tool properties follows.</p> | 
 | 407 | <ul class="simple"> | 
 | 408 | <li>Possible tool properties:<ul> | 
 | 409 | <li><tt class="docutils literal"><span class="pre">in_language</span></tt> - input language name. Can be either a string or a | 
 | 410 | list, in case the tool supports multiple input languages.</li> | 
 | 411 | <li><tt class="docutils literal"><span class="pre">out_language</span></tt> - output language name. Tools are not allowed to | 
 | 412 | have multiple output languages.</li> | 
 | 413 | <li><tt class="docutils literal"><span class="pre">output_suffix</span></tt> - output file suffix. Can also be changed | 
 | 414 | dynamically, see documentation on actions.</li> | 
 | 415 | <li><tt class="docutils literal"><span class="pre">cmd_line</span></tt> - the actual command used to run the tool. You can | 
 | 416 | use <tt class="docutils literal"><span class="pre">$INFILE</span></tt> and <tt class="docutils literal"><span class="pre">$OUTFILE</span></tt> variables, output redirection | 
 | 417 | with <tt class="docutils literal"><span class="pre">></span></tt>, hook invocations (<tt class="docutils literal"><span class="pre">$CALL</span></tt>), environment variables | 
 | 418 | (via <tt class="docutils literal"><span class="pre">$ENV</span></tt>) and the <tt class="docutils literal"><span class="pre">case</span></tt> construct.</li> | 
 | 419 | <li><tt class="docutils literal"><span class="pre">join</span></tt> - this tool is a "join node" in the graph, i.e. it gets a | 
 | 420 | list of input files and joins them together. Used for linkers.</li> | 
 | 421 | <li><tt class="docutils literal"><span class="pre">sink</span></tt> - all command-line options that are not handled by other | 
 | 422 | tools are passed to this tool.</li> | 
 | 423 | <li><tt class="docutils literal"><span class="pre">actions</span></tt> - A single big <tt class="docutils literal"><span class="pre">case</span></tt> expression that specifies how | 
 | 424 | this tool reacts on command-line options (described in more detail | 
 | 425 | below).</li> | 
 | 426 | </ul> | 
 | 427 | </li> | 
 | 428 | </ul> | 
 | 429 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 430 | <h2><a class="toc-backref" href="#id13" id="actions" name="actions">Actions</a></h2> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 431 | <p>A tool often needs to react to command-line options, and this is | 
 | 432 | precisely what the <tt class="docutils literal"><span class="pre">actions</span></tt> property is for. The next example | 
 | 433 | illustrates this feature:</p> | 
 | 434 | <pre class="literal-block"> | 
 | 435 | def llvm_gcc_linker : Tool<[ | 
 | 436 |     (in_language "object-code"), | 
 | 437 |     (out_language "executable"), | 
 | 438 |     (output_suffix "out"), | 
 | 439 |     (cmd_line "llvm-gcc $INFILE -o $OUTFILE"), | 
 | 440 |     (join), | 
 | 441 |     (actions (case (not_empty "L"), (forward "L"), | 
 | 442 |                    (not_empty "l"), (forward "l"), | 
 | 443 |                    (not_empty "dummy"), | 
 | 444 |                              [(append_cmd "-dummy1"), (append_cmd "-dummy2")]) | 
 | 445 |     ]>; | 
 | 446 | </pre> | 
 | 447 | <p>The <tt class="docutils literal"><span class="pre">actions</span></tt> tool property is implemented on top of the omnipresent | 
 | 448 | <tt class="docutils literal"><span class="pre">case</span></tt> expression. It associates one or more different <em>actions</em> | 
 | 449 | with given conditions - in the example, the actions are <tt class="docutils literal"><span class="pre">forward</span></tt>, | 
 | 450 | which forwards a given option unchanged, and <tt class="docutils literal"><span class="pre">append_cmd</span></tt>, which | 
 | 451 | appends a given string to the tool execution command. Multiple actions | 
 | 452 | can be associated with a single condition by using a list of actions | 
 | 453 | (used in the example to append some dummy options). The same <tt class="docutils literal"><span class="pre">case</span></tt> | 
 | 454 | construct can also be used in the <tt class="docutils literal"><span class="pre">cmd_line</span></tt> property to modify the | 
 | 455 | tool command line.</p> | 
 | 456 | <p>The "join" property used in the example means that this tool behaves | 
 | 457 | like a linker.</p> | 
 | 458 | <p>The list of all possible actions follows.</p> | 
 | 459 | <ul> | 
 | 460 | <li><p class="first">Possible actions:</p> | 
 | 461 | <blockquote> | 
 | 462 | <ul class="simple"> | 
 | 463 | <li><tt class="docutils literal"><span class="pre">append_cmd</span></tt> - append a string to the tool invocation | 
 | 464 | command. | 
 | 465 | Example: <tt class="docutils literal"><span class="pre">(case</span> <span class="pre">(switch_on</span> <span class="pre">"pthread"),</span> <span class="pre">(append_cmd</span> <span class="pre">"-lpthread"))</span></tt></li> | 
 | 466 | <li><tt class="docutils literal"><span class="pre">forward</span></tt> - forward an option unchanged. | 
 | 467 | Example: <tt class="docutils literal"><span class="pre">(forward</span> <span class="pre">"Wall")</span></tt>.</li> | 
 | 468 | <li><tt class="docutils literal"><span class="pre">forward_as</span></tt> - Change the name of an option, but forward the | 
 | 469 | argument unchanged. | 
 | 470 | Example: <tt class="docutils literal"><span class="pre">(forward_as</span> <span class="pre">"O0"</span> <span class="pre">"--disable-optimization")</span></tt>.</li> | 
 | 471 | <li><tt class="docutils literal"><span class="pre">output_suffix</span></tt> - modify the output suffix of this | 
 | 472 | tool. | 
 | 473 | Example: <tt class="docutils literal"><span class="pre">(output_suffix</span> <span class="pre">"i")</span></tt>.</li> | 
 | 474 | <li><tt class="docutils literal"><span class="pre">stop_compilation</span></tt> - stop compilation after this tool processes | 
 | 475 | its input. Used without arguments.</li> | 
 | 476 | <li><tt class="docutils literal"><span class="pre">unpack_values</span></tt> - used for for splitting and forwarding | 
 | 477 | comma-separated lists of options, e.g. <tt class="docutils literal"><span class="pre">-Wa,-foo=bar,-baz</span></tt> is | 
 | 478 | converted to <tt class="docutils literal"><span class="pre">-foo=bar</span> <span class="pre">-baz</span></tt> and appended to the tool invocation | 
 | 479 | command. | 
 | 480 | Example: <tt class="docutils literal"><span class="pre">(unpack_values</span> <span class="pre">"Wa,")</span></tt>.</li> | 
 | 481 | </ul> | 
 | 482 | </blockquote> | 
 | 483 | </li> | 
 | 484 | </ul> | 
 | 485 | </div> | 
 | 486 | </div> | 
 | 487 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 488 | <h1><a class="toc-backref" href="#id14" id="language-map" name="language-map">Language map</a></h1> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 489 | <p>If you are adding support for a new language to LLVMC, you'll need to | 
 | 490 | modify the language map, which defines mappings from file extensions | 
 | 491 | to language names. It is used to choose the proper toolchain(s) for a | 
 | 492 | given input file set. Language map definition looks like this:</p> | 
| Anton Korobeynikov | 7412031 | 2008-06-09 04:15:49 +0000 | [diff] [blame] | 493 | <pre class="literal-block"> | 
 | 494 | def LanguageMap : LanguageMap< | 
 | 495 |     [LangToSuffixes<"c++", ["cc", "cp", "cxx", "cpp", "CPP", "c++", "C"]>, | 
 | 496 |      LangToSuffixes<"c", ["c"]>, | 
 | 497 |      ... | 
 | 498 |     ]>; | 
 | 499 | </pre> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 500 | <p>For example, without those definitions the following command wouldn't work:</p> | 
 | 501 | <pre class="literal-block"> | 
 | 502 | $ llvmc hello.cpp | 
 | 503 | llvmc: Unknown suffix: cpp | 
 | 504 | </pre> | 
 | 505 | <p>The language map entries should be added only for tools that are | 
 | 506 | linked with the root node. Since tools are not allowed to have | 
 | 507 | multiple output languages, for nodes "inside" the graph the input and | 
 | 508 | output languages should match. This is enforced at compile-time.</p> | 
| Reid Spencer | 46d2192 | 2004-08-22 18:06:59 +0000 | [diff] [blame] | 509 | </div> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 510 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 511 | <h1><a class="toc-backref" href="#id15" id="more-advanced-topics" name="more-advanced-topics">More advanced topics</a></h1> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 512 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 513 | <h2><a class="toc-backref" href="#id16" id="hooks-and-environment-variables" name="hooks-and-environment-variables"><span id="hooks"></span>Hooks and environment variables</a></h2> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 514 | <p>Normally, LLVMC executes programs from the system <tt class="docutils literal"><span class="pre">PATH</span></tt>. Sometimes, | 
 | 515 | this is not sufficient: for example, we may want to specify tool names | 
 | 516 | in the configuration file. This can be achieved via the mechanism of | 
 | 517 | hooks - to write your own hooks, just add their definitions to the | 
 | 518 | <tt class="docutils literal"><span class="pre">PluginMain.cpp</span></tt> or drop a <tt class="docutils literal"><span class="pre">.cpp</span></tt> file into the | 
 | 519 | <tt class="docutils literal"><span class="pre">$LLVMC_DIR/driver</span></tt> directory. Hooks should live in the <tt class="docutils literal"><span class="pre">hooks</span></tt> | 
 | 520 | namespace and have the signature <tt class="docutils literal"><span class="pre">std::string</span> <span class="pre">hooks::MyHookName</span> | 
 | 521 | <span class="pre">(void)</span></tt>. They can be used from the <tt class="docutils literal"><span class="pre">cmd_line</span></tt> tool property:</p> | 
 | 522 | <pre class="literal-block"> | 
 | 523 | (cmd_line "$CALL(MyHook)/path/to/file -o $CALL(AnotherHook)") | 
 | 524 | </pre> | 
 | 525 | <p>It is also possible to use environment variables in the same manner:</p> | 
 | 526 | <pre class="literal-block"> | 
 | 527 | (cmd_line "$ENV(VAR1)/path/to/file -o $ENV(VAR2)") | 
 | 528 | </pre> | 
 | 529 | <p>To change the command line string based on user-provided options use | 
 | 530 | the <tt class="docutils literal"><span class="pre">case</span></tt> expression (documented <a class="reference" href="#case">above</a>):</p> | 
 | 531 | <pre class="literal-block"> | 
 | 532 | (cmd_line | 
 | 533 |   (case | 
 | 534 |     (switch_on "E"), | 
 | 535 |        "llvm-g++ -E -x c $INFILE -o $OUTFILE", | 
 | 536 |     (default), | 
 | 537 |        "llvm-g++ -c -x c $INFILE -o $OUTFILE -emit-llvm")) | 
 | 538 | </pre> | 
 | 539 | </div> | 
 | 540 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 541 | <h2><a class="toc-backref" href="#id17" id="how-plugins-are-loaded" name="how-plugins-are-loaded"><span id="priorities"></span>How plugins are loaded</a></h2> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 542 | <p>It is possible for LLVMC plugins to depend on each other. For example, | 
 | 543 | one can create edges between nodes defined in some other plugin. To | 
 | 544 | make this work, however, that plugin should be loaded first. To | 
 | 545 | achieve this, the concept of plugin priority was introduced. By | 
 | 546 | default, every plugin has priority zero; to specify the priority | 
 | 547 | explicitly, put the following line in your plugin's TableGen file:</p> | 
 | 548 | <pre class="literal-block"> | 
 | 549 | def Priority : PluginPriority<$PRIORITY_VALUE>; | 
 | 550 | # Where PRIORITY_VALUE is some integer > 0 | 
 | 551 | </pre> | 
 | 552 | <p>Plugins are loaded in order of their (increasing) priority, starting | 
 | 553 | with 0. Therefore, the plugin with the highest priority value will be | 
 | 554 | loaded last.</p> | 
 | 555 | </div> | 
 | 556 | <div class="section"> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 557 | <h2><a class="toc-backref" href="#id18" id="debugging" name="debugging">Debugging</a></h2> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 558 | <p>When writing LLVMC plugins, it can be useful to get a visual view of | 
 | 559 | the resulting compilation graph. This can be achieved via the command | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 560 | line option <tt class="docutils literal"><span class="pre">--view-graph</span></tt>. This command assumes that <a class="reference" href="http://www.graphviz.org/">Graphviz</a> and | 
 | 561 | <a class="reference" href="http://pages.cs.wisc.edu/~ghost/">Ghostview</a> are installed. There is also a <tt class="docutils literal"><span class="pre">--dump-graph</span></tt> option that | 
 | 562 | creates a Graphviz source file (<tt class="docutils literal"><span class="pre">compilation-graph.dot</span></tt>) in the | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 563 | current directory.</p> | 
| Mikhail Glushenkov | 9053154 | 2008-12-11 23:43:14 +0000 | [diff] [blame] | 564 | <hr /> | 
| Anton Korobeynikov | 28b6670 | 2008-06-09 04:17:51 +0000 | [diff] [blame] | 565 | <address> | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 566 | <a href="http://jigsaw.w3.org/css-validator/check/referer"> | 
 | 567 | <img src="http://jigsaw.w3.org/css-validator/images/vcss-blue" | 
 | 568 |    alt="Valid CSS" /></a> | 
 | 569 | <a href="http://validator.w3.org/check?uri=referer"> | 
 | 570 | <img src="http://www.w3.org/Icons/valid-xhtml10-blue" | 
 | 571 |    alt="Valid XHTML 1.0 Transitional"/></a> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 572 |  | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 573 | <a href="mailto:foldr@codedgers.com">Mikhail Glushenkov</a><br /> | 
 | 574 | <a href="http://llvm.org">LLVM Compiler Infrastructure</a><br /> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 575 |  | 
| Mikhail Glushenkov | d565203 | 2008-12-13 02:28:58 +0000 | [diff] [blame] | 576 | Last modified: $Date: 2008-12-11 11:34:48 -0600 (Thu, 11 Dec 2008) $ | 
 | 577 | </address></div> | 
| Mikhail Glushenkov | 68319f8 | 2008-12-11 23:24:40 +0000 | [diff] [blame] | 578 | </div> | 
 | 579 | </div> | 
| Reid Spencer | b1254a1 | 2004-08-09 03:08:29 +0000 | [diff] [blame] | 580 | </body> | 
 | 581 | </html> |