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  10 <h1>LLVM Makefile Guide</h1>
  11
  12 <ol>
  13   <li><a href="#introduction">Introduction</a></li>
  14   <li><a href="#general">General Concepts</a>
  15     <ol>
  16       <li><a href="#projects">Projects</a></li>
  17       <li><a href="#varvals">Variable Values</a></li>
  18       <li><a href="#including">Including Makefiles</a>
  19         <ol>
  20           <li><a href="#Makefile">Makefile</a></li>
  21           <li><a href="#Makefile.common">Makefile.common</a></li>
  22           <li><a href="#Makefile.config">Makefile.config</a></li>
  23           <li><a href="#Makefile.rules">Makefile.rules</a></li>
  24         </ol>
  25       </li>
  26       <li><a href="#Comments">Comments</a></li>
  27     </ol>
  28   </li>
  29   <li><a href="#tutorial">Tutorial</a>
  30     <ol>
  31       <li><a href="#libraries">Libraries</a>
  32         <ol>
  33           <li><a href="#BCModules">Bitcode Modules</a></li>
  34           <li><a href="#LoadableModules">Loadable Modules</a></li>
  35         </ol>
  36       </li>
  37       <li><a href="#tools">Tools</a>
  38         <ol>
  39           <li><a href="#JIT">JIT Tools</a></li>
  40         </ol>
  41       </li>
  42       <li><a href="#projects">Projects</a></li>
  43     </ol>
  44   </li>
  45   <li><a href="#targets">Targets Supported</a>
  46     <ol>
  47       <li><a href="#all">all</a></li>
  48       <li><a href="#all-local">all-local</a></li>
  49       <li><a href="#check">check</a></li>
  50       <li><a href="#check-local">check-local</a></li>
  51       <li><a href="#clean">clean</a></li>
  52       <li><a href="#clean-local">clean-local</a></li>
  53       <li><a href="#dist">dist</a></li>
  54       <li><a href="#dist-check">dist-check</a></li>
  55       <li><a href="#dist-clean">dist-clean</a></li>
  56       <li><a href="#install">install</a></li>
  57       <li><a href="#preconditions">preconditions</a></li>
  58       <li><a href="#printvars">printvars</a></li>
  59       <li><a href="#reconfigure">reconfigure</a></li>
  60       <li><a href="#spotless">spotless</a></li>
  61       <li><a href="#tags">tags</a></li>
  62       <li><a href="#uninstall">uninstall</a></li>
  63     </ol>
  64   </li>
  65   <li><a href="#variables">Using Variables</a>
  66     <ol>
  67       <li><a href="#setvars">Control Variables</a></li>
  68       <li><a href="#overvars">Override Variables</a></li>
  69       <li><a href="#getvars">Readable Variables</a></li>
  70       <li><a href="#intvars">Internal Variables</a></li>
  71     </ol>
  72   </li>
  73 </ol>
  74
  75 <div class="doc_author">
  76   <p>Written by <a href="mailto:reid@x10sys.com">Reid Spencer</a></p>
  77 </div>
  78
  79 <!-- *********************************************************************** -->
  80 <h2><a name="introduction">Introduction</a></h2>
  81 <!-- *********************************************************************** -->
  82
  83 <div>
  84   <p>This document provides <em>usage</em> information about the LLVM makefile
  85   system. While loosely patterned after the BSD makefile system, LLVM has taken
  86   a departure from BSD in order to implement additional features needed by LLVM.
  87   Although makefile systems such as automake were attempted at one point, it
  88   has become clear that the features needed by LLVM and the Makefile norm are
  89   too great to use a more limited tool. Consequently, LLVM requires simply GNU
  90   Make 3.79, a widely portable makefile processor. LLVM unabashedly makes heavy
  91   use of the features of GNU Make so the dependency on GNU Make is firm. If
  92   you're not familiar with <tt>make</tt>, it is recommended that you read the
  93   <a href="http://www.gnu.org/software/make/manual/make.html">GNU Makefile
  94   Manual</a>.</p>
  95   <p>While this document is rightly part of the
  96   <a href="ProgrammersManual.html">LLVM Programmer's Manual</a>, it is treated
  97   separately here because of the volume of content and because it is often an
  98   early source of bewilderment for new developers.</p>
  99 </div>
 100
 101 <!-- *********************************************************************** -->
 102 <h2><a name="general">General Concepts</a></h2>
 103 <!-- *********************************************************************** -->
 104
 105 <div>
 106   <p>The LLVM Makefile System is the component of LLVM that is responsible for
 107   building the software, testing it,  generating distributions, checking those
 108   distributions, installing and uninstalling, etc. It consists of a several
 109   files throughout the source tree. These files and other general concepts are
 110   described in this section.</p>
 111
 112 <!-- ======================================================================= -->
 113 <h3><a name="projects">Projects</a></h3>
 114 <div>
 115   <p>The LLVM Makefile System is quite generous. It not only builds its own
 116   software, but it can build yours too. Built into the system is knowledge of
 117   the <tt>llvm/projects</tt> directory. Any directory under <tt>projects</tt>
 118   that has both a <tt>configure</tt> script and a <tt>Makefile</tt> is assumed
 119   to be a project that uses the LLVM Makefile system.  Building software that
 120   uses LLVM does not require the LLVM Makefile System nor even placement in the
 121   <tt>llvm/projects</tt> directory. However, doing so will allow your project
 122   to get up and running quickly by utilizing the built-in features that are used
 123   to compile LLVM. LLVM compiles itself using the same features of the makefile
 124   system as used for projects.</p>
 125   <p>For complete details on setting up your projects configuration, simply
 126   mimic the <tt>llvm/projects/sample</tt> project or for further details,
 127   consult the <a href="Projects.html">Projects.html</a> page.</p>
 128 </div>
 129
 130 <!-- ======================================================================= -->
 131 <h3><a name="varvalues">Variable Values</a></h3>
 132 <div>
 133   <p>To use the makefile system, you simply create a file named
 134   <tt>Makefile</tt> in your directory and declare values for certain variables.
 135   The variables and values that you select determine what the makefile system
 136   will do. These variables enable rules and processing in the makefile system
 137   that automatically Do The Right Thing&trade;.
 138 </div>
 139
 140 <!-- ======================================================================= -->
 141 <h3><a name="including">Including Makefiles</a></h3>
 142 <div>
 143   <p>Setting variables alone is not enough. You must include into your Makefile
 144   additional files that provide the rules of the LLVM Makefile system. The
 145   various files involved are described in the sections that follow.</p>
 146
 147 <!-- ======================================================================= -->
 148 <h4><a name="Makefile">Makefile</a></h4>
 149 <div>
 150   <p>Each directory to participate in the build needs to have a file named
 151   <tt>Makefile</tt>. This is the file first read by <tt>make</tt>. It has three
 152   sections:</p>
 153   <ol>
 154     <li><a href="#setvars">Settable Variables</a> - Required that must be set
 155     first.</li>
 156     <li><a href="#Makefile.common">include <tt>$(LEVEL)/Makefile.common</tt></a>
 157     - include the LLVM Makefile system.
 158     <li><a href="#overvars">Override Variables</a> - Override variables set by
 159     the LLVM Makefile system.
 160   </ol>
 161 </div>
 162
 163 <!-- ======================================================================= -->
 164 <h4><a name="Makefile.common">Makefile.common</a></h4>
 165 <div>
 166   <p>Every project must have a <tt>Makefile.common</tt> file at its top source
 167   directory. This file serves three purposes:</p>
 168   <ol>
 169     <li>It includes the project's configuration makefile to obtain values
 170     determined by the <tt>configure</tt> script. This is done by including the
 171     <a href="#Makefile.config"><tt>$(LEVEL)/Makefile.config</tt></a> file.</li>
 172     <li>It specifies any other (static) values that are needed throughout the
 173     project. Only values that are used in all or a large proportion of the
 174     project's directories should be placed here.</li>
 175     <li>It includes the standard rules for the LLVM Makefile system,
 176     <a href="#Makefile.rules"><tt>$(LLVM_SRC_ROOT)/Makefile.rules</tt></a>.
 177     This file is the "guts" of the LLVM Makefile system.</li>
 178   </ol>
 179 </div>
 180
 181 <!-- ======================================================================= -->
 182 <h4><a name="Makefile.config">Makefile.config</a></h4>
 183 <div>
 184   <p>Every project must have a <tt>Makefile.config</tt> at the top of its
 185   <em>build</em> directory. This file is <b>generated</b> by the
 186   <tt>configure</tt> script from the pattern provided by the
 187   <tt>Makefile.config.in</tt> file located at the top of the project's
 188   <em>source</em> directory. The contents of this file depend largely on what
 189   configuration items the project uses, however most projects can get what they
 190   need by just relying on LLVM's configuration found in
 191   <tt>$(LLVM_OBJ_ROOT)/Makefile.config</tt>.
 192 </div>
 193
 194 <!-- ======================================================================= -->
 195 <h4><a name="Makefile.rules">Makefile.rules</a></h4>
 196 <div>
 197   <p>This file, located at <tt>$(LLVM_SRC_ROOT)/Makefile.rules</tt> is the heart
 198   of the LLVM Makefile System. It provides all the logic, dependencies, and
 199   rules for building the targets supported by the system. What it does largely
 200   depends on the values of <tt>make</tt> <a href="#variables">variables</a> that
 201   have been set <em>before</em> <tt>Makefile.rules</tt> is included.
 202 </div>
 203
 204 </div>
 205
 206 <!-- ======================================================================= -->
 207 <h3><a name="Comments">Comments</a></h3>
 208 <div>
 209   <p>User Makefiles need not have comments in them unless the construction is
 210   unusual or it does not strictly follow the rules and patterns of the LLVM
 211   makefile system. Makefile comments are invoked with the pound (#) character.
 212   The # character and any text following it, to the end of the line, are ignored
 213   by <tt>make</tt>.</p>
 214 </div>
 215
 216 </div>
 217
 218 <!-- *********************************************************************** -->
 219 <h2><a name="tutorial">Tutorial</a></h2>
 220 <!-- *********************************************************************** -->
 221 <div>
 222   <p>This section provides some examples of the different kinds of modules you
 223   can build with the LLVM makefile system. In general, each directory you
 224   provide will build a single object although that object may be composed of
 225   additionally compiled components.</p>
 226
 227 <!-- ======================================================================= -->
 228 <h3><a name="libraries">Libraries</a></h3>
 229 <div>
 230   <p>Only a few variable definitions are needed to build a regular library.
 231   Normally, the makefile system will build all the software into a single
 232   <tt>libname.o</tt> (pre-linked) object. This means the library is not
 233   searchable and that the distinction between compilation units has been
 234   dissolved. Optionally, you can ask for a shared library (.so) or archive
 235   library (.a) built.  Archive libraries are the default. For example:</p>
 236   <pre><tt>
 237       LIBRARYNAME = mylib
 238       SHARED_LIBRARY = 1
 239       ARCHIVE_LIBRARY = 1
 240   </tt></pre>
 241   <p>says to build a library named "mylib" with both a shared library
 242   (<tt>mylib.so</tt>) and an archive library (<tt>mylib.a</tt>) version. The
 243   contents of all the
 244   libraries produced will be the same, they are just constructed differently.
 245   Note that you normally do not need to specify the sources involved. The LLVM
 246   Makefile system will infer the source files from the contents of the source
 247   directory.</p>
 248   <p>The <tt>LOADABLE_MODULE=1</tt> directive can be used in conjunction with
 249   <tt>SHARED_LIBRARY=1</tt> to indicate that the resulting shared library should
 250   be openable with the <tt>dlopen</tt> function and searchable with the
 251   <tt>dlsym</tt> function (or your operating system's equivalents). While this
 252   isn't strictly necessary on Linux and a few other platforms, it is required
 253   on systems like HP-UX and Darwin. You should use <tt>LOADABLE_MODULE</tt> for
 254   any shared library that you intend to be loaded into an tool via the
 255   <tt>-load</tt> option. See the
 256   <a href="WritingAnLLVMPass.html#makefile">WritingAnLLVMPass.html</a> document
 257   for an example of why you might want to do this.
 258
 259 <!-- ======================================================================= -->
 260 <h4><a name="BCModules">Bitcode Modules</a></h4>
 261 <div>
 262   <p>In some situations, it is desirable to build a single bitcode module from
 263   a variety of sources, instead of an archive, shared library, or bitcode
 264   library. Bitcode modules can be specified in addition to any of the other
 265   types of libraries by defining the <a href="#MODULE_NAME">MODULE_NAME</a>
 266   variable. For example:</p>
 267   <pre><tt>
 268       LIBRARYNAME = mylib
 269       BYTECODE_LIBRARY = 1
 270       MODULE_NAME = mymod
 271   </tt></pre>
 272   <p>will build a module named <tt>mymod.bc</tt> from the sources in the
 273   directory. This module will be an aggregation of all the bitcode modules
 274   derived from the sources. The example will also build a bitcode archive
 275   containing a bitcode module for each compiled source file. The difference is
 276   subtle, but important depending on how the module or library is to be linked.
 277   </p>
 278 </div>
 279
 280 <!-- ======================================================================= -->
 281 <h4>
 282   <a name="LoadableModules">Loadable Modules</a>
 283 </h4>
 284 <div>
 285   <p>In some situations, you need to create a loadable module. Loadable modules
 286   can be loaded into programs like <tt>opt</tt> or <tt>llc</tt> to specify
 287   additional passes to run or targets to support.  Loadable modules are also
 288   useful for debugging a pass or providing a pass with another package if that
 289   pass can't be included in LLVM.</p>
 290   <p>LLVM provides complete support for building such a module. All you need to
 291   do is use the LOADABLE_MODULE variable in your Makefile. For example, to
 292   build a loadable module named <tt>MyMod</tt> that uses the LLVM libraries
 293   <tt>LLVMSupport.a</tt> and <tt>LLVMSystem.a</tt>, you would specify:</p>
 294   <pre><tt>
 295      LIBRARYNAME := MyMod
 296      LOADABLE_MODULE := 1
 297      LINK_COMPONENTS := support system
 298   </tt></pre>
 299   <p>Use of the <tt>LOADABLE_MODULE</tt> facility implies several things:</p>
 300   <ol>
 301     <li>There will be no "lib" prefix on the module. This differentiates it from
 302     a standard shared library of the same name.</li>
 303     <li>The <a href="#SHARED_LIBRARY">SHARED_LIBRARY</a> variable is turned
 304     on.</li>
 305     <li>The <a href="#LINK_LIBS_IN_SHARED">LINK_LIBS_IN_SHARED</a> variable
 306     is turned on.</li>
 307   </ol>
 308   <p>A loadable module is loaded by LLVM via the facilities of libtool's libltdl
 309   library which is part of <tt>lib/System</tt> implementation.</p>
 310 </div>
 311
 312 </div>
 313
 314 <!-- ======================================================================= -->
 315 <h3><a name="tools">Tools</a></h3>
 316 <div>
 317   <p>For building executable programs (tools), you must provide the name of the
 318   tool and the names of the libraries you wish to link with the tool. For
 319   example:</p>
 320   <pre><tt>
 321       TOOLNAME = mytool
 322       USEDLIBS = mylib
 323       LINK_COMPONENTS = support system
 324   </tt></pre>
 325   <p>says that we are to build a tool name <tt>mytool</tt> and that it requires
 326   three libraries: <tt>mylib</tt>, <tt>LLVMSupport.a</tt> and
 327   <tt>LLVMSystem.a</tt>.</p>
 328   <p>Note that two different variables are use to indicate which libraries are
 329   linked: <tt>USEDLIBS</tt> and <tt>LLVMLIBS</tt>. This distinction is necessary
 330   to support projects. <tt>LLVMLIBS</tt> refers to the LLVM libraries found in
 331   the LLVM object directory. <tt>USEDLIBS</tt> refers to the libraries built by
 332   your project. In the case of building LLVM tools, <tt>USEDLIBS</tt> and
 333   <tt>LLVMLIBS</tt> can be used interchangeably since the "project" is LLVM
 334   itself and <tt>USEDLIBS</tt> refers to the same place as <tt>LLVMLIBS</tt>.
 335   </p>
 336   <p>Also note that there are two different ways of specifying a library: with a
 337   <tt>.a</tt> suffix and without. Without the suffix, the entry refers to the
 338   re-linked (.o) file which will include <em>all</em> symbols of the library.
 339   This is useful, for example, to include all passes from a library of passes.
 340   If the <tt>.a</tt> suffix is used then the library is linked as a searchable
 341   library (with the <tt>-l</tt> option). In this case, only the symbols that are
 342   unresolved <em>at that point</em> will be resolved from the library, if they
 343   exist. Other (unreferenced) symbols will not be included when the <tt>.a</tt>
 344   syntax is used. Note that in order to use the <tt>.a</tt> suffix, the library
 345   in question must have been built with the <tt>ARCHIVE_LIBRARY</tt> option set.
 346   </p>
 347
 348 <!-- ======================================================================= -->
 349 <h4><a name="JIT">JIT Tools</a></h4>
 350 <div>
 351   <p>Many tools will want to use the JIT features of LLVM.  To do this, you
 352      simply specify that you want an execution 'engine', and the makefiles will
 353      automatically link in the appropriate JIT for the host or an interpreter
 354      if none is available:</p>
 355   <pre><tt>
 356       TOOLNAME = my_jit_tool
 357       USEDLIBS = mylib
 358       LINK_COMPONENTS = engine
 359   </tt></pre>
 360   <p>Of course, any additional libraries may be listed as other components.  To
 361   get a full understanding of how this changes the linker command, it is
 362   recommended that you:</p>
 363   <pre><tt>
 364       cd examples/Fibonacci
 365       make VERBOSE=1
 366   </tt></pre>
 367 </div>
 368
 369 </div>
 370
 371 </div>
 372
 373 <!-- *********************************************************************** -->
 374 <h2><a name="targets">Targets Supported</a></h2>
 375 <!-- *********************************************************************** -->
 376
 377 <div>
 378   <p>This section describes each of the targets that can be built using the LLVM
 379   Makefile system. Any target can be invoked from any directory but not all are
 380   applicable to a given directory (e.g. "check", "dist" and "install" will
 381   always operate as if invoked from the top level directory).</p>
 382
 383   <table style="text-align:left">
 384     <tr>
 385       <th>Target Name</th><th>Implied Targets</th><th>Target Description</th>
 386     </tr>
 387     <tr><td><a href="#all"><tt>all</tt></a></td><td></td>
 388       <td>Compile the software recursively. Default target.
 389     </td></tr>
 390     <tr><td><a href="#all-local"><tt>all-local</tt></a></td><td></td>
 391       <td>Compile the software in the local directory only.
 392     </td></tr>
 393     <tr><td><a href="#check"><tt>check</tt></a></td><td></td>
 394       <td>Change to the <tt>test</tt> directory in a project and run the
 395       test suite there.
 396     </td></tr>
 397     <tr><td><a href="#check-local"><tt>check-local</tt></a></td><td></td>
 398       <td>Run a local test suite. Generally this is only defined in the
 399         <tt>Makefile</tt> of the project's <tt>test</tt> directory.
 400     </td></tr>
 401     <tr><td><a href="#clean"><tt>clean</tt></a></td><td></td>
 402       <td>Remove built objects recursively.
 403     </td></tr>
 404     <tr><td><a href="#clean-local"><tt>clean-local</tt></a></td><td></td>
 405       <td>Remove built objects from the local directory only.
 406     </td></tr>
 407     <tr><td><a href="#dist"><tt>dist</tt></a></td><td>all</td>
 408       <td>Prepare a source distribution tarball.
 409     </td></tr>
 410     <tr><td><a href="#dist-check"><tt>dist-check</tt></a></td><td>all</td>
 411       <td>Prepare a source distribution tarball and check that it builds.
 412     </td></tr>
 413     <tr><td><a href="#dist-clean"><tt>dist-clean</tt></a></td><td>clean</td>
 414       <td>Clean source distribution tarball temporary files.
 415     </td></tr>
 416     <tr><td><a href="#install"><tt>install</tt></a></td><td>all</td>
 417       <td>Copy built objects to installation directory.
 418     </td></tr>
 419     <tr><td><a href="#preconditions"><tt>preconditions</tt></a></td><td>all</td>
 420       <td>Check to make sure configuration and makefiles are up to date.
 421     </td></tr>
 422     <tr><td><a href="#printvars"><tt>printvars</tt></a></td><td>all</td>
 423       <td>Prints variables defined by the makefile system (for debugging).
 424     </td></tr>
 425     <tr><td><a href="#tags"><tt>tags</tt></a></td><td></td>
 426       <td>Make C and C++ tags files for emacs and vi.
 427     </td></tr>
 428     <tr><td><a href="#uninstall"><tt>uninstall</tt></a></td><td></td>
 429       <td>Remove built objects from installation directory.
 430     </td></tr>
 431   </table>
 432
 433 <!-- ======================================================================= -->
 434 <h3><a name="all">all (default)</a></h3>
 435 <div>
 436   <p>When you invoke <tt>make</tt> with no arguments, you are implicitly
 437   instructing it to seek the "all" target (goal). This target is used for
 438   building the software recursively and will do different things in different
 439   directories.  For example, in a <tt>lib</tt> directory, the "all" target will
 440   compile source files and generate libraries. But, in a <tt>tools</tt>
 441   directory, it will link libraries and generate executables.</p>
 442 </div>
 443
 444 <!-- ======================================================================= -->
 445 <h3><a name="all-local">all-local</a></h3>
 446 <div>
 447   <p>This target is the same as <a href="#all">all</a> but it operates only on
 448   the current directory instead of recursively.</p>
 449 </div>
 450
 451 <!-- ======================================================================= -->
 452 <h3><a name="check">check</a></h3>
 453 <div>
 454   <p>This target can be invoked from anywhere within a project's directories
 455   but always invokes the <a href="#check-local"><tt>check-local</tt></a> target
 456   in the project's <tt>test</tt> directory, if it exists and has a
 457   <tt>Makefile</tt>. A warning is produced otherwise.  If
 458   <a href="#TESTSUITE"><tt>TESTSUITE</tt></a> is defined on the <tt>make</tt>
 459   command line, it will be passed down to the invocation of
 460   <tt>make check-local</tt> in the <tt>test</tt> directory. The intended usage
 461   for this is to assist in running specific suites of tests. If
 462   <tt>TESTSUITE</tt> is not set, the implementation of <tt>check-local</tt>
 463   should run all normal tests.  It is up to the project to define what
 464   different values for <tt>TESTSUTE</tt> will do. See the
 465   <a href="TestingGuide.html">TestingGuide</a> for further details.</p>
 466 </div>
 467
 468 <!-- ======================================================================= -->
 469 <h3><a name="check-local">check-local</a></h3>
 470 <div>
 471   <p>This target should be implemented by the <tt>Makefile</tt> in the project's
 472   <tt>test</tt> directory. It is invoked by the <tt>check</tt> target elsewhere.
 473   Each project is free to define the actions of <tt>check-local</tt> as
 474   appropriate for that project. The LLVM project itself uses dejagnu to run a
 475   suite of feature and regresson tests. Other projects may choose to use
 476   dejagnu or any other testing mechanism.</p>
 477 </div>
 478
 479 <!-- ======================================================================= -->
 480 <h3><a name="clean">clean</a></h3>
 481 <div>
 482   <p>This target cleans the build directory, recursively removing all things
 483   that the Makefile builds. The cleaning rules have been made guarded so they
 484   shouldn't go awry (via <tt>rm -f $(UNSET_VARIABLE)/*</tt> which will attempt
 485   to erase the entire directory structure.</p>
 486 </div>
 487
 488 <!-- ======================================================================= -->
 489 <h3><a name="clean-local">clean-local</a></h3>
 490 <div>
 491   <p>This target does the same thing as <tt>clean</tt> but only for the current
 492   (local) directory.</p>
 493 </div>
 494
 495 <!-- ======================================================================= -->
 496 <h3><a name="dist">dist</a></h3>
 497 <div>
 498   <p>This target builds a distribution tarball. It first builds the entire
 499   project using the <tt>all</tt> target and then tars up the necessary files and
 500   compresses it. The generated tarball is sufficient for a casual source
 501   distribution, but probably not for a release (see <tt>dist-check</tt>).</p>
 502 </div>
 503
 504 <!-- ======================================================================= -->
 505 <h3><a name="dist-check">dist-check</a></h3>
 506 <div>
 507   <p>This target does the same thing as the <tt>dist</tt> target but also checks
 508   the distribution tarball. The check is made by unpacking the tarball to a new
 509   directory, configuring it, building it, installing it, and then verifying that
 510   the installation results are correct (by comparing to the original build).
 511   This target can take a long time to run but should be done before a release
 512   goes out to make sure that the distributed tarball can actually be built into
 513   a working release.</p>
 514 </div>
 515
 516 <!-- ======================================================================= -->
 517 <h3><a name="dist-clean">dist-clean</a></h3>
 518 <div>
 519   <p>This is a special form of the <tt>clean</tt> clean target. It performs a
 520   normal <tt>clean</tt> but also removes things pertaining to building the
 521   distribution.</p>
 522 </div>
 523
 524 <!-- ======================================================================= -->
 525 <h3><a name="install">install</a></h3>
 526 <div>
 527   <p>This target finalizes shared objects and executables and copies all
 528   libraries, headers, executables and documentation to the directory given
 529   with the <tt>--prefix</tt> option to <tt>configure</tt>.  When completed,
 530   the prefix directory will have everything needed to <b>use</b> LLVM. </p>
 531   <p>The LLVM makefiles can generate complete <b>internal</b> documentation
 532   for all the classes by using <tt>doxygen</tt>. By default, this feature is
 533   <b>not</b> enabled because it takes a long time and generates a massive
 534   amount of data (>100MB). If you want this feature, you must configure LLVM
 535   with the --enable-doxygen switch and ensure that a modern version of doxygen
 536   (1.3.7 or later) is available in your <tt>PATH</tt>. You can download
 537   doxygen from
 538   <a href="http://www.stack.nl/~dimitri/doxygen/download.html#latestsrc">
 539   here</a>.
 540 </div>
 541
 542 <!-- ======================================================================= -->
 543 <h3><a name="preconditions">preconditions</a></h3>
 544 <div>
 545   <p>This utility target checks to see if the <tt>Makefile</tt> in the object
 546   directory is older than the <tt>Makefile</tt> in the source directory and
 547   copies it if so. It also reruns the <tt>configure</tt> script if that needs to
 548   be done and rebuilds the <tt>Makefile.config</tt> file similarly. Users may
 549   overload this target to ensure that sanity checks are run <em>before</em> any
 550   building of targets as all the targets depend on <tt>preconditions</tt>.</p>
 551 </div>
 552
 553 <!-- ======================================================================= -->
 554 <h3><a name="printvars">printvars</a></h3>
 555 <div>
 556   <p>This utility target just causes the LLVM makefiles to print out some of
 557   the makefile variables so that you can double check how things are set. </p>
 558 </div>
 559
 560 <!-- ======================================================================= -->
 561 <h3><a name="reconfigure">reconfigure</a></h3>
 562 <div>
 563   <p>This utility target will force a reconfigure of LLVM or your project. It
 564   simply runs <tt>$(PROJ_OBJ_ROOT)/config.status --recheck</tt> to rerun the
 565   configuration tests and rebuild the configured files. This isn't generally
 566   useful as the makefiles will reconfigure themselves whenever its necessary.
 567   </p>
 568 </div>
 569
 570 <!-- ======================================================================= -->
 571 <h3><a name="spotless">spotless</a></h3>
 572 <div>
 573   <p>This utility target, only available when <tt>$(PROJ_OBJ_ROOT)</tt> is not
 574   the same as <tt>$(PROJ_SRC_ROOT)</tt>, will completely clean the
 575   <tt>$(PROJ_OBJ_ROOT)</tt> directory by removing its content entirely and
 576   reconfiguring the directory. This returns the <tt>$(PROJ_OBJ_ROOT)</tt>
 577   directory to a completely fresh state. All content in the directory except
 578   configured files and top-level makefiles will be lost.</p>
 579   <div class="doc_warning"><p>Use with caution.</p></div>
 580 </div>
 581
 582 <!-- ======================================================================= -->
 583 <h3><a name="tags">tags</a></h3>
 584 <div>
 585   <p>This target will generate a <tt>TAGS</tt> file in the top-level source
 586   directory. It is meant for use with emacs, XEmacs, or ViM. The TAGS file
 587   provides an index of symbol definitions so that the editor can jump you to the
 588   definition quickly. </p>
 589 </div>
 590
 591 <!-- ======================================================================= -->
 592 <h3><a name="uninstall">uninstall</a></h3>
 593 <div>
 594   <p>This target is the opposite of the <tt>install</tt> target. It removes the
 595   header, library and executable files from the installation directories. Note
 596   that the directories themselves are not removed because it is not guaranteed
 597   that LLVM is the only thing installing there (e.g. --prefix=/usr).</p>
 598 </div>
 599
 600 </div>
 601
 602 <!-- *********************************************************************** -->
 603 <h2><a name="variables">Variables</a></h2>
 604 <!-- *********************************************************************** -->
 605 <div>
 606   <p>Variables are used to tell the LLVM Makefile System what to do and to
 607   obtain information from it. Variables are also used internally by the LLVM
 608   Makefile System. Variable names that contain only the upper case alphabetic
 609   letters and underscore are intended for use by the end user. All other
 610   variables are internal to the LLVM Makefile System and should not be relied
 611   upon nor modified. The sections below describe how to use the LLVM Makefile
 612   variables.</p>
 613
 614 <!-- ======================================================================= -->
 615 <h3><a name="setvars">Control Variables</a></h3>
 616 <div>
 617   <p>Variables listed in the table below should be set <em>before</em> the
 618   inclusion of <a href="#Makefile.common"><tt>$(LEVEL)/Makefile.common</tt></a>.
 619   These variables provide input to the LLVM make system that tell it what to do
 620   for the current directory.</p>
 621   <dl>
 622     <dt><a name="BUILD_ARCHIVE"><tt>BUILD_ARCHIVE</tt></a></dt>
 623     <dd>If set to any value, causes an archive (.a) library to be built.</dd>
 624     <dt><a name="BUILT_SOURCES"><tt>BUILT_SOURCES</tt></a></dt>
 625     <dd>Specifies a set of source files that are generated from other source
 626     files. These sources will be built before any other target processing to
 627     ensure they are present.</dd>
 628     <dt><a name="BYTECODE_LIBRARY"><tt>BYTECODE_LIBRARY</tt></a></dt>
 629     <dd>If set to any value, causes a bitcode library (.bc) to be built.</dd>
 630     <dt><a name="CONFIG_FILES"><tt>CONFIG_FILES</tt></a></dt>
 631     <dd>Specifies a set of configuration files to be installed.</dd>
 632     <dt><a name="DEBUG_SYMBOLS"><tt>DEBUG_SYMBOLS</tt></a></dt>
 633     <dd>If set to any value, causes the build to include debugging
 634     symbols even in optimized objects, libraries and executables. This
 635     alters the flags specified to the compilers and linkers. Debugging
 636     isn't fun in an optimized build, but it is possible.</dd>
 637     <dt><a name="DIRS"><tt>DIRS</tt></a></dt>
 638     <dd>Specifies a set of directories, usually children of the current
 639     directory, that should also be made using the same goal. These directories
 640     will be built serially.</dd>
 641     <dt><a name="DISABLE_AUTO_DEPENDENCIES"><tt>DISABLE_AUTO_DEPENDENCIES</tt></a></dt>
 642     <dd>If set to any value, causes the makefiles to <b>not</b> automatically
 643     generate dependencies when running the compiler. Use of this feature is
 644     discouraged and it may be removed at a later date.</dd>
 645     <dt><a name="ENABLE_OPTIMIZED"><tt>ENABLE_OPTIMIZED</tt></a></dt>
 646     <dd>If set to 1, causes the build to generate optimized objects,
 647     libraries and executables. This alters the flags specified to the compilers
 648     and linkers. Generally debugging won't be a fun experience with an optimized
 649     build.</dd>
 650     <dt><a name="ENABLE_PROFILING"><tt>ENABLE_PROFILING</tt></a></dt>
 651     <dd>If set to 1, causes the build to generate both optimized and
 652     profiled objects, libraries and executables. This alters the flags specified
 653     to the compilers and linkers to ensure that profile data can be collected
 654     from the tools built. Use the <tt>gprof</tt> tool to analyze the output from
 655     the profiled tools (<tt>gmon.out</tt>).</dd>
 656     <dt><a name="DISABLE_ASSERTIONS"><tt>DISABLE_ASSERTIONS</tt></a></dt>
 657     <dd>If set to 1, causes the build to disable assertions, even if
 658     building a debug or profile build.  This will exclude all assertion check
 659     code from the build. LLVM will execute faster, but with little help when
 660     things go wrong.</dd>
 661     <dt><a name="EXPERIMENTAL_DIRS"><tt>EXPERIMENTAL_DIRS</tt></a></dt>
 662     <dd>Specify a set of directories that should be built, but if they fail, it
 663     should not cause the build to fail. Note that this should only be used
 664     temporarily while code is being written.</dd>
 665     <dt><a name="EXPORTED_SYMBOL_FILE"><tt>EXPORTED_SYMBOL_FILE</tt></a></dt>
 666     <dd>Specifies the name of a single file that contains a list of the
 667     symbols to be exported by the linker. One symbol per line.</dd>
 668     <dt><a name="EXPORTED_SYMBOL_LIST"><tt>EXPORTED_SYMBOL_LIST</tt></a></dt>
 669     <dd>Specifies a set of symbols to be exported by the linker.</dd>
 670     <dt><a name="EXTRA_DIST"><tt>EXTRA_DIST</tt></a></dt>
 671     <dd>Specifies additional files that should be distributed with LLVM. All
 672     source files, all built sources, all Makefiles, and most documentation files
 673     will be automatically distributed. Use this variable to distribute any
 674     files that are not automatically distributed.</dd>
 675     <dt><a name="KEEP_SYMBOLS"><tt>KEEP_SYMBOLS</tt></a></dt>
 676     <dd>If set to any value, specifies that when linking executables the
 677     makefiles should retain debug symbols in the executable. Normally, symbols
 678     are stripped from the executable.</dd>
 679     <dt><a name="LEVEL"><tt>LEVEL</tt></a><small>(required)</small></dt>
 680     <dd>Specify the level of nesting from the top level. This variable must be
 681     set in each makefile as it is used to find the top level and thus the other
 682     makefiles.</dd>
 683     <dt><a name="LIBRARYNAME"><tt>LIBRARYNAME</tt></a></dt>
 684     <dd>Specify the name of the library to be built. (Required For
 685     Libraries)</dd>
 686     <dt><a name="LINK_COMPONENTS"><tt>LINK_COMPONENTS</tt></a></dt>
 687     <dd>When specified for building a tool, the value of this variable will be
 688     passed to the <tt>llvm-config</tt> tool to generate a link line for the
 689     tool. Unlike <tt>USEDLIBS</tt> and <tt>LLVMLIBS</tt>, not all libraries need
 690     to be specified. The <tt>llvm-config</tt> tool will figure out the library
 691     dependencies and add any libraries that are needed. The <tt>USEDLIBS</tt>
 692     variable can still be used in conjunction with <tt>LINK_COMPONENTS</tt> so
 693     that additional project-specific libraries can be linked with the LLVM
 694     libraries specified by <tt>LINK_COMPONENTS</tt></dd>
 695     <dt><a name="LINK_LIBS_IN_SHARED"><tt>LINK_LIBS_IN_SHARED</tt></a></dt>
 696     <dd>By default, shared library linking will ignore any libraries specified
 697     with the <a href="LLVMLIBS">LLVMLIBS</a> or <a href="USEDLIBS">USEDLIBS</a>.
 698     This prevents shared libs from including things that will be in the LLVM
 699     tool the shared library will be loaded into. However, sometimes it is useful
 700     to link certain libraries into your shared library and this option enables
 701     that feature.</dd>
 702     <dt><a name="LLVMLIBS"><tt>LLVMLIBS</tt></a></dt>
 703     <dd>Specifies the set of libraries from the LLVM $(ObjDir) that will be
 704     linked into the tool or library.</dd>
 705     <dt><a name="LOADABLE_MODULE"><tt>LOADABLE_MODULE</tt></a></dt>
 706     <dd>If set to any value, causes the shared library being built to also be
 707     a loadable module. Loadable modules can be opened with the dlopen() function
 708     and searched with dlsym (or the operating system's equivalent). Note that
 709     setting this variable without also setting <tt>SHARED_LIBRARY</tt> will have
 710     no effect.</dd>
 711     <dt><a name="MODULE_NAME"><tt>MODULE_NAME</tt></a></dt>
 712     <dd>Specifies the name of a bitcode module to be created. A bitcode
 713     module can be specified in conjunction with other kinds of library builds
 714     or by itself. It constructs from the sources a single linked bitcode
 715     file.</dd>
 716     <dt><a name="NO_INSTALL"><tt>NO_INSTALL</tt></a></dt>
 717     <dd>Specifies that the build products of the directory should not be
 718     installed but should be built even if the <tt>install</tt> target is given.
 719     This is handy for directories that build libraries or tools that are only
 720     used as part of the build process, such as code generators (e.g.
 721     <tt>tblgen</tt>).</dd>
 722     <dt><a name="OPTIONAL_DIRS"><tt>OPTIONAL_DIRS</tt></a></dt>
 723     <dd>Specify a set of directories that may be built, if they exist, but its
 724     not an error for them not to exist.</dd>
 725     <dt><a name="PARALLEL_DIRS"><tt>PARALLEL_DIRS</tt></a></dt>
 726     <dd>Specify a set of directories to build recursively and in parallel if
 727     the -j option was used with <tt>make</tt>.</dd>
 728     <dt><a name="SHARED_LIBRARY"><tt>SHARED_LIBRARY</tt></a></dt>
 729     <dd>If set to any value, causes a shared library (.so) to be built in
 730     addition to any other kinds of libraries. Note that this option will cause
 731     all source files to be built twice: once with options for position
 732     independent code and once without. Use it only where you really need a
 733     shared library.</dd>
 734     <dt><a name="SOURCES"><tt>SOURCES</tt><small>(optional)</small></a></dt>
 735     <dd>Specifies the list of source files in the current directory to be
 736     built. Source files of any type may be specified (programs, documentation,
 737     config files, etc.). If not specified, the makefile system will infer the
 738     set of source files from the files present in the current directory.</dd>
 739     <dt><a name="SUFFIXES"><tt>SUFFIXES</tt></a></dt>
 740     <dd>Specifies a set of filename suffixes that occur in suffix match rules.
 741     Only set this if your local <tt>Makefile</tt> specifies additional suffix
 742     match rules.</dd>
 743     <dt><a name="TARGET"><tt>TARGET</tt></a></dt>
 744     <dd>Specifies the name of the LLVM code generation target that the
 745     current directory builds. Setting this variable enables additional rules to
 746     build <tt>.inc</tt> files from <tt>.td</tt> files. </dd>
 747     <dt><a name="TESTSUITE"><tt>TESTSUITE</tt></a></dt>
 748     <dd>Specifies the directory of tests to run in <tt>llvm/test</tt>.</dd>
 749     <dt><a name="TOOLNAME"><tt>TOOLNAME</tt></a></dt>
 750     <dd>Specifies the name of the tool that the current directory should
 751     build.</dd>
 752     <dt><a name="TOOL_VERBOSE"><tt>TOOL_VERBOSE</tt></a></dt>
 753     <dd>Implies VERBOSE and also tells each tool invoked to be verbose. This is
 754     handy when you're trying to see the sub-tools invoked by each tool invoked
 755     by the makefile. For example, this will pass <tt>-v</tt> to the GCC
 756     compilers which causes it to print out the command lines it uses to invoke
 757     sub-tools (compiler, assembler, linker).</dd>
 758     <dt><a name="USEDLIBS"><tt>USEDLIBS</tt></a></dt>
 759     <dd>Specifies the list of project libraries that will be linked into the
 760     tool or library.</dd>
 761     <dt><a name="VERBOSE"><tt>VERBOSE</tt></a></dt>
 762     <dd>Tells the Makefile system to produce detailed output of what it is doing
 763     instead of just summary comments. This will generate a LOT of output.</dd>
 764   </dl>
 765 </div>
 766
 767 <!-- ======================================================================= -->
 768 <h3><a name="overvars">Override Variables</a></h3>
 769 <div>
 770   <p>Override variables can be used to override the default
 771   values provided by the LLVM makefile system. These variables can be set in
 772   several ways:</p>
 773   <ul>
 774     <li>In the environment (e.g. setenv, export) -- not recommended.</li>
 775     <li>On the <tt>make</tt> command line -- recommended.</li>
 776     <li>On the <tt>configure</tt> command line</li>
 777     <li>In the Makefile (only <em>after</em> the inclusion of <a
 778     href="#Makefile.common"><tt>$(LEVEL)/Makefile.common</tt></a>).</li>
 779   </ul>
 780   <p>The override variables are given below:</p>
 781   <dl>
 782     <dt><a name="AR"><tt>AR</tt></a> <small>(defaulted)</small></dt>
 783     <dd>Specifies the path to the <tt>ar</tt> tool.</dd>
 784     <dt><a name="PROJ_OBJ_DIR"><tt>PROJ_OBJ_DIR</tt></a></dt>
 785     <dd>The directory into which the products of build rules will be placed.
 786     This might be the same as
 787     <a href="#PROJ_SRC_DIR"><tt>PROJ_SRC_DIR</tt></a> but typically is
 788     not.</dd>
 789     <dt><a name="PROJ_SRC_DIR"><tt>PROJ_SRC_DIR</tt></a></dt>
 790     <dd>The directory which contains the source files to be built.</dd>
 791     <dt><a name="BUILD_EXAMPLES"><tt>BUILD_EXAMPLES</tt></a></dt>
 792     <dd>If set to 1, build examples in <tt>examples</tt> and (if building
 793     Clang) <tt>tools/clang/examples</tt> directories.</dd>
 794     <dt><a name="BZIP2"><tt>BZIP2</tt></a><small>(configured)</small></dt>
 795     <dd>The path to the <tt>bzip2</tt> tool.</dd>
 796     <dt><a name="CC"><tt>CC</tt></a><small>(configured)</small></dt>
 797     <dd>The path to the 'C' compiler.</dd>
 798     <dt><a name="CFLAGS"><tt>CFLAGS</tt></a></dt>
 799     <dd>Additional flags to be passed to the 'C' compiler.</dd>
 800     <dt><a name="CXX"><tt>CXX</tt></a></dt>
 801     <dd>Specifies the path to the C++ compiler.</dd>
 802     <dt><a name="CXXFLAGS"><tt>CXXFLAGS</tt></a></dt>
 803     <dd>Additional flags to be passed to the C++ compiler.</dd>
 804     <dt><a name="DATE"><tt>DATE<small>(configured)</small></tt></a></dt>
 805     <dd>Specifies the path to the <tt>date</tt> program or any program that can
 806     generate the current date and time on its standard output</dd>
 807     <dt><a name="DOT"><tt>DOT</tt></a><small>(configured)</small></dt>
 808     <dd>Specifies the path to the <tt>dot</tt> tool or <tt>false</tt> if there
 809     isn't one.</dd>
 810     <dt><a name="ECHO"><tt>ECHO</tt></a><small>(configured)</small></dt>
 811     <dd>Specifies the path to the <tt>echo</tt> tool for printing output.</dd>
 812     <dt><a name="EXEEXT"><tt>EXEEXT</tt></a><small>(configured)</small></dt>
 813     <dd>Provides the extension to be used on executables built by the makefiles.
 814     The value may be empty on platforms that do not use file extensions for
 815     executables (e.g. Unix).</dd>
 816     <dt><a name="INSTALL"><tt>INSTALL</tt></a><small>(configured)</small></dt>
 817     <dd>Specifies the path to the <tt>install</tt> tool.</dd>
 818     <dt><a name="LDFLAGS"><tt>LDFLAGS</tt></a><small>(configured)</small></dt>
 819     <dd>Allows users to specify additional flags to pass to the linker.</dd>
 820     <dt><a name="LIBS"><tt>LIBS</tt></a><small>(configured)</small></dt>
 821     <dd>The list of libraries that should be linked with each tool.</dd>
 822     <dt><a name="LIBTOOL"><tt>LIBTOOL</tt></a><small>(configured)</small></dt>
 823     <dd>Specifies the path to the <tt>libtool</tt> tool. This tool is renamed
 824     <tt>mklib</tt> by the <tt>configure</tt> script and always located in the
 825     <dt><a name="LLVMAS"><tt>LLVMAS</tt></a><small>(defaulted)</small></dt>
 826     <dd>Specifies the path to the <tt>llvm-as</tt> tool.</dd>
 827     <dt><a name="LLVMCC"><tt>LLVMCC</tt></a></dt>
 828     <dd>Specifies the path to the LLVM capable compiler.</dd>
 829     <dt><a name="LLVMCXX"><tt>LLVMCXX</tt></a></dt>
 830     <dd>Specifies the path to the LLVM C++ capable compiler.</dd>
 831     <dt><a name="LLVMGCC"><tt>LLVMGCC</tt></a><small>(defaulted)</small></dt>
 832     <dd>Specifies the path to the LLVM version of the GCC 'C' Compiler</dd>
 833     <dt><a name="LLVMGXX"><tt>LLVMGXX</tt></a><small>(defaulted)</small></dt>
 834     <dd>Specifies the path to the LLVM version of the GCC C++ Compiler</dd>
 835     <dt><a name="LLVMLD"><tt>LLVMLD</tt></a><small>(defaulted)</small></dt>
 836     <dd>Specifies the path to the LLVM bitcode linker tool</dd>
 837     <dt><a name="LLVM_OBJ_ROOT"><tt>LLVM_OBJ_ROOT</tt></a><small>(configured)
 838     </small></dt>
 839     <dd>Specifies the top directory into which the output of the build is
 840     placed.</dd>
 841     <dt><a name="LLVM_SRC_ROOT"><tt>LLVM_SRC_ROOT</tt></a><small>(configured)
 842     </small></dt>
 843     <dd>Specifies the top directory in which the sources are found.</dd>
 844     <dt><a name="LLVM_TARBALL_NAME"><tt>LLVM_TARBALL_NAME</tt></a>
 845     <small>(configured)</small></dt>
 846     <dd>Specifies the name of the distribution tarball to create. This is
 847     configured from the name of the project and its version number.</dd>
 848     <dt><a name="MKDIR"><tt>MKDIR</tt></a><small>(defaulted)</small></dt>
 849     <dd>Specifies the path to the <tt>mkdir</tt> tool that creates
 850     directories.</dd>
 851     <dt><a name="ONLY_TOOLS"><tt>ONLY_TOOLS</tt></a></dt>
 852     <dd>If set, specifies the list of tools to build.</dd>
 853     <dt><a name="PLATFORMSTRIPOPTS"><tt>PLATFORMSTRIPOPTS</tt></a></dt>
 854     <dd>The options to provide to the linker to specify that a stripped (no
 855     symbols) executable should be built.</dd>
 856     <dt><a name="RANLIB"><tt>RANLIB</tt></a><small>(defaulted)</small></dt>
 857     <dd>Specifies the path to the <tt>ranlib</tt> tool.</dd>
 858     <dt><a name="RM"><tt>RM</tt></a><small>(defaulted)</small></dt>
 859     <dd>Specifies the path to the <tt>rm</tt> tool.</dd>
 860     <dt><a name="SED"><tt>SED</tt></a><small>(defaulted)</small></dt>
 861     <dd>Specifies the path to the <tt>sed</tt> tool.</dd>
 862     <dt><a name="SHLIBEXT"><tt>SHLIBEXT</tt></a><small>(configured)</small></dt>
 863     <dd>Provides the filename extension to use for shared libraries.</dd>
 864     <dt><a name="TBLGEN"><tt>TBLGEN</tt></a><small>(defaulted)</small></dt>
 865     <dd>Specifies the path to the <tt>tblgen</tt> tool.</dd>
 866     <dt><a name="TAR"><tt>TAR</tt></a><small>(defaulted)</small></dt>
 867     <dd>Specifies the path to the <tt>tar</tt> tool.</dd>
 868     <dt><a name="ZIP"><tt>ZIP</tt></a><small>(defaulted)</small></dt>
 869     <dd>Specifies the path to the <tt>zip</tt> tool.</dd>
 870   </dl>
 871 </div>
 872
 873 <!-- ======================================================================= -->
 874 <h3><a name="getvars">Readable Variables</a></h3>
 875 <div>
 876   <p>Variables listed in the table below can be used by the user's Makefile but
 877   should not be changed. Changing the value will generally cause the build to go
 878   wrong, so don't do it.</p>
 879   <dl>
 880     <dt><a name="bindir"><tt>bindir</tt></a></dt>
 881     <dd>The directory into which executables will ultimately be installed. This
 882     value is derived from the <tt>--prefix</tt> option given to
 883     <tt>configure</tt>.</dd>
 884     <dt><a name="BuildMode"><tt>BuildMode</tt></a></dt>
 885     <dd>The name of the type of build being performed: Debug, Release, or
 886     Profile</dd>
 887     <dt><a name="bitcode_libdir"><tt>bytecode_libdir</tt></a></dt>
 888     <dd>The directory into which bitcode libraries will ultimately be
 889     installed.  This value is derived from the <tt>--prefix</tt> option given to
 890     <tt>configure</tt>.</dd>
 891     <dt><a name="ConfigureScriptFLAGS"><tt>ConfigureScriptFLAGS</tt></a></dt>
 892     <dd>Additional flags given to the <tt>configure</tt> script when
 893     reconfiguring.</dd>
 894     <dt><a name="DistDir"><tt>DistDir</tt></a></dt>
 895     <dd>The <em>current</em> directory for which a distribution copy is being
 896     made.</dd>
 897     <dt><a name="Echo"><tt>Echo</tt></a></dt>
 898     <dd>The LLVM Makefile System output command. This provides the
 899     <tt>llvm[n]</tt> prefix and starts with @ so the command itself is not
 900     printed by <tt>make</tt>.</dd>
 901     <dt><a name="EchoCmd"><tt>EchoCmd</tt></a></dt>
 902     <dd> Same as <a href="#Echo"><tt>Echo</tt></a> but without the leading @.
 903     </dd>
 904     <dt><a name="includedir"><tt>includedir</tt></a></dt>
 905     <dd>The directory into which include files will ultimately be installed.
 906     This value is derived from the <tt>--prefix</tt> option given to
 907     <tt>configure</tt>.</dd>
 908     <dt><a name="libdir"><tt>libdir</tt></a></dt><dd></dd>
 909     <dd>The directory into which native libraries will ultimately be installed.
 910     This value is derived from the <tt>--prefix</tt> option given to
 911     <tt>configure</tt>.</dd>
 912     <dt><a name="LibDir"><tt>LibDir</tt></a></dt>
 913     <dd>The configuration specific directory into which libraries are placed
 914     before installation.</dd>
 915     <dt><a name="MakefileConfig"><tt>MakefileConfig</tt></a></dt>
 916     <dd>Full path of the <tt>Makefile.config</tt> file.</dd>
 917     <dt><a name="MakefileConfigIn"><tt>MakefileConfigIn</tt></a></dt>
 918     <dd>Full path of the <tt>Makefile.config.in</tt> file.</dd>
 919     <dt><a name="ObjDir"><tt>ObjDir</tt></a></dt>
 920     <dd>The configuration and directory specific directory where build objects
 921     (compilation results) are placed.</dd>
 922     <dt><a name="SubDirs"><tt>SubDirs</tt></a></dt>
 923     <dd>The complete list of sub-directories of the current directory as
 924     specified by other variables.</dd>
 925     <dt><a name="Sources"><tt>Sources</tt></a></dt>
 926     <dd>The complete list of source files.</dd>
 927     <dt><a name="sysconfdir"><tt>sysconfdir</tt></a></dt>
 928     <dd>The directory into which configuration files will ultimately be
 929     installed. This value is derived from the <tt>--prefix</tt> option given to
 930     <tt>configure</tt>.</dd>
 931     <dt><a name="ToolDir"><tt>ToolDir</tt></a></dt>
 932     <dd>The configuration specific directory into which executables are placed
 933     before they are installed.</dd>
 934     <dt><a name="TopDistDir"><tt>TopDistDir</tt></a></dt>
 935     <dd>The top most directory into which the distribution files are copied.
 936     </dd>
 937     <dt><a name="Verb"><tt>Verb</tt></a></dt>
 938     <dd>Use this as the first thing on your build script lines to enable or
 939     disable verbose mode. It expands to either an @ (quiet mode) or nothing
 940     (verbose mode). </dd>
 941   </dl>
 942 </div>
 943
 944 <!-- ======================================================================= -->
 945 <h3><a name="intvars">Internal Variables</a></h3>
 946 <div>
 947   <p>Variables listed below are used by the LLVM Makefile System
 948   and considered internal. You should not use these variables under any
 949   circumstances.</p>
 950   <p><tt>
 951     Archive
 952     AR.Flags
 953     BaseNameSources
 954     BCCompile.C
 955     BCCompile.CXX
 956     BCLinkLib
 957     C.Flags
 958     Compile.C
 959     CompileCommonOpts
 960     Compile.CXX
 961     ConfigStatusScript
 962     ConfigureScript
 963     CPP.Flags
 964     CPP.Flags
 965     CXX.Flags
 966     DependFiles
 967     DestArchiveLib
 968     DestBitcodeLib
 969     DestModule
 970     DestSharedLib
 971     DestTool
 972     DistAlways
 973     DistCheckDir
 974     DistCheckTop
 975     DistFiles
 976     DistName
 977     DistOther
 978     DistSources
 979     DistSubDirs
 980     DistTarBZ2
 981     DistTarGZip
 982     DistZip
 983     ExtraLibs
 984     FakeSources
 985     INCFiles
 986     InternalTargets
 987     LD.Flags
 988     LibName.A
 989     LibName.BC
 990     LibName.LA
 991     LibName.O
 992     LibTool.Flags
 993     Link
 994     LinkModule
 995     LLVMLibDir
 996     LLVMLibsOptions
 997     LLVMLibsPaths
 998     LLVMToolDir
 999     LLVMUsedLibs
1000     LocalTargets
1001     Module
1002     ObjectsBC
1003     ObjectsLO
1004     ObjectsO
1005     ObjMakefiles
1006     ParallelTargets
1007     PreConditions
1008     ProjLibsOptions
1009     ProjLibsPaths
1010     ProjUsedLibs
1011     Ranlib
1012     RecursiveTargets
1013     SrcMakefiles
1014     Strip
1015     StripWarnMsg
1016     TableGen
1017     TDFiles
1018     ToolBuildPath
1019     TopLevelTargets
1020     UserTargets
1021   </tt></p>
1022 </div>
1023
1024 </div>
1025
1026 <!-- *********************************************************************** -->
1027 <hr>
1028 <address>
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1033
1034   <a href="mailto:rspencer@x10sys.com">Reid Spencer</a><br>
1035   <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
1036   Last modified: $Date$
1037 </address>
1038 </body>
1039 </html>