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10 <div class="doc_title">LLVM Makefile Guide</div>
13 <li><a href="#introduction">Introduction</a></li>
14 <li><a href="#general">General Concepts</a>
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>
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>
26 <li><a href="#Comments">Comments</a></li>
29 <li><a href="#tutorial">Tutorial</a>
31 <li><a href="#libraries">Libraries</a>
33 <li><a href="#BCModules">Bitcode Modules</a></li>
34 <li><a href="#LoadableModules">Loadable Modules</a></li>
37 <li><a href="#tools">Tools</a>
39 <li><a href="#JIT">JIT Tools</a></li>
42 <li><a href="#projects">Projects</a></li>
45 <li><a href="#targets">Targets Supported</a>
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>
65 <li><a href="#variables">Using Variables</a>
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>
75 <div class="doc_author">
76 <p>Written by <a href="mailto:reid@x10sys.com">Reid Spencer</a></p>
79 <!-- *********************************************************************** -->
80 <div class="doc_section"><a name="introduction">Introduction </a></div>
81 <!-- *********************************************************************** -->
83 <div class="doc_text">
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
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>
101 <!-- *********************************************************************** -->
102 <div class="doc_section"><a name="general">General Concepts</a></div>
103 <!-- *********************************************************************** -->
105 <div class="doc_text">
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>
113 <!-- ======================================================================= -->
114 <div class="doc_subsection"><a name="projects">Projects</a></div>
115 <div class="doc_text">
116 <p>The LLVM Makefile System is quite generous. It not only builds its own
117 software, but it can build yours too. Built into the system is knowledge of
118 the <tt>llvm/projects</tt> directory. Any directory under <tt>projects</tt>
119 that has both a <tt>configure</tt> script and a <tt>Makefile</tt> is assumed
120 to be a project that uses the LLVM Makefile system. Building software that
121 uses LLVM does not require the LLVM Makefile System nor even placement in the
122 <tt>llvm/projects</tt> directory. However, doing so will allow your project
123 to get up and running quickly by utilizing the built-in features that are used
124 to compile LLVM. LLVM compiles itself using the same features of the makefile
125 system as used for projects.</p>
126 <p>For complete details on setting up your projects configuration, simply
127 mimic the <tt>llvm/projects/sample</tt> project or for further details,
128 consult the <a href="Projects.html">Projects.html</a> page.</p>
131 <!-- ======================================================================= -->
132 <div class="doc_subsection"><a name="varvalues">Variable Values</a></div>
133 <div class="doc_text">
134 <p>To use the makefile system, you simply create a file named
135 <tt>Makefile</tt> in your directory and declare values for certain variables.
136 The variables and values that you select determine what the makefile system
137 will do. These variables enable rules and processing in the makefile system
138 that automatically Do The Right Thing™.
141 <!-- ======================================================================= -->
142 <div class="doc_subsection"><a name="including">Including Makefiles</a></div>
143 <div class="doc_text">
144 <p>Setting variables alone is not enough. You must include into your Makefile
145 additional files that provide the rules of the LLVM Makefile system. The
146 various files involved are described in the sections that follow.</p>
149 <!-- ======================================================================= -->
150 <div class="doc_subsubsection"><a name="Makefile">Makefile</a></div>
151 <div class="doc_text">
152 <p>Each directory to participate in the build needs to have a file named
153 <tt>Makefile</tt>. This is the file first read by <tt>make</tt>. It has three
156 <li><a href="#setvars">Settable Variables</a> - Required that must be set
158 <li><a href="#Makefile.common">include <tt>$(LEVEL)/Makefile.common</tt></a>
159 - include the LLVM Makefile system.
160 <li><a href="#overvars">Override Variables</a> - Override variables set by
161 the LLVM Makefile system.
165 <!-- ======================================================================= -->
166 <div class="doc_subsubsection"><a name="Makefile.common">Makefile.common</a>
168 <div class="doc_text">
169 <p>Every project must have a <tt>Makefile.common</tt> file at its top source
170 directory. This file serves three purposes:</p>
172 <li>It includes the project's configuration makefile to obtain values
173 determined by the <tt>configure</tt> script. This is done by including the
174 <a href="#Makefile.config"><tt>$(LEVEL)/Makefile.config</tt></a> file.</li>
175 <li>It specifies any other (static) values that are needed throughout the
176 project. Only values that are used in all or a large proportion of the
177 project's directories should be placed here.</li>
178 <li>It includes the standard rules for the LLVM Makefile system,
179 <a href="#Makefile.rules"><tt>$(LLVM_SRC_ROOT)/Makefile.rules</tt></a>.
180 This file is the "guts" of the LLVM Makefile system.</li>
184 <!-- ======================================================================= -->
185 <div class="doc_subsubsection"><a name="Makefile.config">Makefile.config</a>
187 <div class="doc_text">
188 <p>Every project must have a <tt>Makefile.config</tt> at the top of its
189 <em>build</em> directory. This file is <b>generated</b> by the
190 <tt>configure</tt> script from the pattern provided by the
191 <tt>Makefile.config.in</tt> file located at the top of the project's
192 <em>source</em> directory. The contents of this file depend largely on what
193 configuration items the project uses, however most projects can get what they
194 need by just relying on LLVM's configuration found in
195 <tt>$(LLVM_OBJ_ROOT)/Makefile.config</tt>.
198 <!-- ======================================================================= -->
199 <div class="doc_subsubsection"><a name="Makefile.rules">Makefile.rules</a></div>
200 <div class="doc_text">
201 <p>This file, located at <tt>$(LLVM_SRC_ROOT)/Makefile.rules</tt> is the heart
202 of the LLVM Makefile System. It provides all the logic, dependencies, and
203 rules for building the targets supported by the system. What it does largely
204 depends on the values of <tt>make</tt> <a href="#variables">variables</a> that
205 have been set <em>before</em> <tt>Makefile.rules</tt> is included.
208 <!-- ======================================================================= -->
209 <div class="doc_subsection"><a name="Comments">Comments</a></div>
210 <div class="doc_text">
211 <p>User Makefiles need not have comments in them unless the construction is
212 unusual or it does not strictly follow the rules and patterns of the LLVM
213 makefile system. Makefile comments are invoked with the pound (#) character.
214 The # character and any text following it, to the end of the line, are ignored
215 by <tt>make</tt>.</p>
218 <!-- *********************************************************************** -->
219 <div class="doc_section"><a name="tutorial">Tutorial</a></div>
220 <!-- *********************************************************************** -->
221 <div class="doc_text">
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>
228 <!-- ======================================================================= -->
229 <div class="doc_subsection"><a name="libraries">Libraries</a></div>
230 <div class="doc_text">
231 <p>Only a few variable definitions are needed to build a regular library.
232 Normally, the makefile system will build all the software into a single
233 <tt>libname.o</tt> (pre-linked) object. This means the library is not
234 searchable and that the distinction between compilation units has been
235 dissolved. Optionally, you can ask for a shared library (.so), archive library
236 (.a) or to not have the default (relinked) library built. For example:</p>
241 DONT_BUILD_RELINKED = 1
243 <p>says to build a library named "mylib" with both a shared library
244 (<tt>mylib.so</tt>) and an archive library (<tt>mylib.a</tt>) version but
245 not to build the relinked object (<tt>mylib.o</tt>). The contents of all the
246 libraries produced will be the same, they are just constructed differently.
247 Note that you normally do not need to specify the sources involved. The LLVM
248 Makefile system will infer the source files from the contents of the source
250 <p>The <tt>LOADABLE_MODULE=1</tt> directive can be used in conjunction with
251 <tt>SHARED_LIBRARY=1</tt> to indicate that the resulting shared library should
252 be openable with the <tt>dlopen</tt> function and searchable with the
253 <tt>dlsym</tt> function (or your operating system's equivalents). While this
254 isn't strictly necessary on Linux and a few other platforms, it is required
255 on systems like HP-UX and Darwin. You should use <tt>LOADABLE_MODULE</tt> for
256 any shared library that you intend to be loaded into an tool via the
257 <tt>-load</tt> option. See the
258 <a href="WritingAnLLVMPass.html#makefile">WritingAnLLVMPass.html</a> document
259 for an example of why you might want to do this.
262 <!-- ======================================================================= -->
263 <div class="doc_subsubsection"><a name="BCModules">Bitcode Modules</a></div>
264 <div class="doc_text">
265 <p>In some situations, it is desireable to build a single bitcode module from
266 a variety of sources, instead of an archive, shared library, or bitcode
267 library. Bitcode modules can be specified in addition to any of the other
268 types of libraries by defining the <a href="#MODULE_NAME">MODULE_NAME</a>
269 variable. For example:</p>
275 <p>will build a module named <tt>mymod.bc</tt> from the sources in the
276 directory. This module will be an aggregation of all the bitcode modules
277 derived from the sources. The example will also build a bitcode archive
278 containing a bitcode module for each compiled source file. The difference is
279 subtle, but important depending on how the module or library is to be linked.
283 <!-- ======================================================================= -->
284 <div class="doc_subsubsection">
285 <a name="LoadableModules">Loadable Modules</a>
287 <div class="doc_text">
288 <p>In some situations, you need to create a loadable module. Loadable modules
289 can be loaded into programs like <tt>opt</tt> or <tt>llc</tt> to specify
290 additional passes to run or targets to support. Loadable modules are also
291 useful for debugging a pass or providing a pass with another package if that
292 pass can't be included in LLVM.</p>
293 <p>LLVM provides complete support for building such a module. All you need to
294 do is use the LOADABLE_MODULE variable in your Makefile. For example, to
295 build a loadable module named <tt>MyMod</tt> that uses the LLVM libraries
296 <tt>LLVMSupport.a</tt> and <tt>LLVMSystem.a</tt>, you would specify:</p>
300 LINK_COMPONENTS := support system
302 <p>Use of the <tt>LOADABLE_MODULE</tt> facility implies several things:</p>
304 <li>There will be no "lib" prefix on the module. This differentiates it from
305 a standard shared library of the same name.</li>
306 <li>The <a href="#SHARED_LIBRARY">SHARED_LIBRARY</a> variable is turned
308 <li>The <a href="#LINK_LIBS_IN_SHARED">LINK_LIBS_IN_SHARED</a> variable
310 <li>The <a href="#DONT_BUILD_RELINKED">DONT_BUILD_RELINKED</a> variable
313 <p>A loadable module is loaded by LLVM via the facilities of libtool's libltdl
314 library which is part of <tt>lib/System</tt> implementation.</p>
317 <!-- ======================================================================= -->
318 <div class="doc_subsection"><a name="tools">Tools</a></div>
319 <div class="doc_text">
320 <p>For building executable programs (tools), you must provide the name of the
321 tool and the names of the libraries you wish to link with the tool. For
326 LINK_COMPONENTS = support system
328 <p>says that we are to build a tool name <tt>mytool</tt> and that it requires
329 three libraries: <tt>mylib</tt>, <tt>LLVMSupport.a</tt> and
330 <tt>LLVMSystem.a</tt>.</p>
331 <p>Note that two different variables are use to indicate which libraries are
332 linked: <tt>USEDLIBS</tt> and <tt>LLVMLIBS</tt>. This distinction is necessary
333 to support projects. <tt>LLVMLIBS</tt> refers to the LLVM libraries found in
334 the LLVM object directory. <tt>USEDLIBS</tt> refers to the libraries built by
335 your project. In the case of building LLVM tools, <tt>USEDLIBS</tt> and
336 <tt>LLVMLIBS</tt> can be used interchangeably since the "project" is LLVM
337 itself and <tt>USEDLIBS</tt> refers to the same place as <tt>LLVMLIBS</tt>.
339 <p>Also note that there are two different ways of specifying a library: with a
340 <tt>.a</tt> suffix and without. Without the suffix, the entry refers to the
341 re-linked (.o) file which will include <em>all</em> symbols of the library.
342 This is useful, for example, to include all passes from a library of passes.
343 If the <tt>.a</tt> suffix is used then the library is linked as a searchable
344 library (with the <tt>-l</tt> option). In this case, only the symbols that are
345 unresolved <em>at that point</em> will be resolved from the library, if they
346 exist. Other (unreferenced) symbols will not be included when the <tt>.a</tt>
347 syntax is used. Note that in order to use the <tt>.a</tt> suffix, the library
348 in question must have been built with the <tt>ARCHIVE_LIBRARY</tt> option set.
352 <!-- ======================================================================= -->
353 <div class="doc_subsubsection"><a name="JIT">JIT Tools</a></div>
354 <div class="doc_text">
355 <p>Many tools will want to use the JIT features of LLVM. To do this, you
356 simply specify that you want an execution 'engine', and the makefiles will
357 automatically link in the appropriate JIT for the host or an interpreter
358 if none is available:</p>
360 TOOLNAME = my_jit_tool
362 LINK_COMPONENTS = engine
364 <p>Of course, any additional libraries may be listed as other components. To
365 get a full understanding of how this changes the linker command, it is
366 recommended that you:</p>
368 cd examples/Fibonacci
373 <!-- *********************************************************************** -->
374 <div class="doc_section"><a name="targets">Targets Supported</a></div>
375 <!-- *********************************************************************** -->
377 <div class="doc_text">
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>
383 <table style="text-align:left">
385 <th>Target Name</th><th>Implied Targets</th><th>Target Description</th>
387 <tr><td><a href="#all"><tt>all</tt></a></td><td></td>
388 <td>Compile the software recursively. Default target.
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.
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
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.
401 <tr><td><a href="#clean"><tt>clean</tt></a></td><td></td>
402 <td>Remove built objects recursively.
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.
407 <tr><td><a href="#dist"><tt>dist</tt></a></td><td>all</td>
408 <td>Prepare a source distribution tarball.
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.
413 <tr><td><a href="#dist-clean"><tt>dist-clean</tt></a></td><td>clean</td>
414 <td>Clean source distribution tarball temporary files.
416 <tr><td><a href="#install"><tt>install</tt></a></td><td>all</td>
417 <td>Copy built objects to installation directory.
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.
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).
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.
428 <tr><td><a href="#uninstall"><tt>uninstall</tt></a></td><td></td>
429 <td>Remove built objects from installation directory.
434 <!-- ======================================================================= -->
435 <div class="doc_subsection"><a name="all">all (default)</a></div>
436 <div class="doc_text">
437 <p>When you invoke <tt>make</tt> with no arguments, you are implicitly
438 instructing it to seek the "all" target (goal). This target is used for
439 building the software recursively and will do different things in different
440 directories. For example, in a <tt>lib</tt> directory, the "all" target will
441 compile source files and generate libraries. But, in a <tt>tools</tt>
442 directory, it will link libraries and generate executables.</p>
445 <!-- ======================================================================= -->
446 <div class="doc_subsection"><a name="all-local">all-local</a></div>
447 <div class="doc_text">
448 <p>This target is the same as <a href="#all">all</a> but it operates only on
449 the current directory instead of recursively.</p>
452 <!-- ======================================================================= -->
453 <div class="doc_subsection"><a name="check">check</a></div>
454 <div class="doc_text">
455 <p>This target can be invoked from anywhere within a project's directories
456 but always invokes the <a href="#check-local"><tt>check-local</tt></a> target
457 in the project's <tt>test</tt> directory, if it exists and has a
458 <tt>Makefile</tt>. A warning is produced otherwise. If
459 <a href="#TESTSUITE"><tt>TESTSUITE</tt></a> is defined on the <tt>make</tt>
460 command line, it will be passed down to the invocation of
461 <tt>make check-local</tt> in the <tt>test</tt> directory. The intended usage
462 for this is to assist in running specific suites of tests. If
463 <tt>TESTSUITE</tt> is not set, the implementation of <tt>check-local</tt>
464 should run all normal tests. It is up to the project to define what
465 different values for <tt>TESTSUTE</tt> will do. See the
466 <a href="TestingGuide.html">TestingGuide</a> for further details.</p>
469 <!-- ======================================================================= -->
470 <div class="doc_subsection"><a name="check-local">check-local</a></div>
471 <div class="doc_text">
472 <p>This target should be implemented by the <tt>Makefile</tt> in the project's
473 <tt>test</tt> directory. It is invoked by the <tt>check</tt> target elsewhere.
474 Each project is free to define the actions of <tt>check-local</tt> as
475 appropriate for that project. The LLVM project itself uses dejagnu to run a
476 suite of feature and regresson tests. Other projects may choose to use
477 dejagnu or any other testing mechanism.</p>
480 <!-- ======================================================================= -->
481 <div class="doc_subsection"><a name="clean">clean</a></div>
482 <div class="doc_text">
483 <p>This target cleans the build directory, recursively removing all things
484 that the Makefile builds. The cleaning rules have been made guarded so they
485 shouldn't go awry (via <tt>rm -f $(UNSET_VARIABLE)/*</tt> which will attempt
486 to erase the entire directory structure.</p>
489 <!-- ======================================================================= -->
490 <div class="doc_subsection"><a name="clean-local">clean-local</a></div>
491 <div class="doc_text">
492 <p>This target does the same thing as <tt>clean</tt> but only for the current
493 (local) directory.</p>
496 <!-- ======================================================================= -->
497 <div class="doc_subsection"><a name="dist">dist</a></div>
498 <div class="doc_text">
499 <p>This target builds a distribution tarball. It first builds the entire
500 project using the <tt>all</tt> target and then tars up the necessary files and
501 compresses it. The generated tarball is sufficient for a casual source
502 distribution, but probably not for a release (see <tt>dist-check</tt>).</p>
505 <!-- ======================================================================= -->
506 <div class="doc_subsection"><a name="dist-check">dist-check</a></div>
507 <div class="doc_text">
508 <p>This target does the same thing as the <tt>dist</tt> target but also checks
509 the distribution tarball. The check is made by unpacking the tarball to a new
510 directory, configuring it, building it, installing it, and then verifying that
511 the installation results are correct (by comparing to the original build).
512 This target can take a long time to run but should be done before a release
513 goes out to make sure that the distributed tarball can actually be built into
514 a working release.</p>
517 <!-- ======================================================================= -->
518 <div class="doc_subsection"><a name="dist-clean">dist-clean</a></div>
519 <div class="doc_text">
520 <p>This is a special form of the <tt>clean</tt> clean target. It performs a
521 normal <tt>clean</tt> but also removes things pertaining to building the
525 <!-- ======================================================================= -->
526 <div class="doc_subsection"><a name="install">install</a></div>
527 <div class="doc_text">
528 <p>This target finalizes shared objects and executables and copies all
529 libraries, headers, executables and documentation to the directory given
530 with the <tt>--prefix</tt> option to <tt>configure</tt>. When completed,
531 the prefix directory will have everything needed to <b>use</b> LLVM. </p>
532 <p>The LLVM makefiles can generate complete <b>internal</b> documentation
533 for all the classes by using <tt>doxygen</tt>. By default, this feature is
534 <b>not</b> enabled because it takes a long time and generates a massive
535 amount of data (>100MB). If you want this feature, you must configure LLVM
536 with the --enable-doxygen switch and ensure that a modern version of doxygen
537 (1.3.7 or later) is available in your <tt>PATH</tt>. You can download
539 <a href="http://www.stack.nl/~dimitri/doxygen/download.html#latestsrc">
543 <!-- ======================================================================= -->
544 <div class="doc_subsection"><a name="preconditions">preconditions</a></div>
545 <div class="doc_text">
546 <p>This utility target checks to see if the <tt>Makefile</tt> in the object
547 directory is older than the <tt>Makefile</tt> in the source directory and
548 copies it if so. It also reruns the <tt>configure</tt> script if that needs to
549 be done and rebuilds the <tt>Makefile.config</tt> file similarly. Users may
550 overload this target to ensure that sanity checks are run <em>before</em> any
551 building of targets as all the targets depend on <tt>preconditions</tt>.</p>
554 <!-- ======================================================================= -->
555 <div class="doc_subsection"><a name="printvars">printvars</a></div>
556 <div class="doc_text">
557 <p>This utility target just causes the LLVM makefiles to print out some of
558 the makefile variables so that you can double check how things are set. </p>
561 <!-- ======================================================================= -->
562 <div class="doc_subsection"><a name="reconfigure">reconfigure</a></div>
563 <div class="doc_text">
564 <p>This utility target will force a reconfigure of LLVM or your project. It
565 simply runs <tt>$(PROJ_OBJ_ROOT)/config.status --recheck</tt> to rerun the
566 configuration tests and rebuild the configured files. This isn't generally
567 useful as the makefiles will reconfigure themselves whenever its necessary.
571 <!-- ======================================================================= -->
572 <div class="doc_subsection"><a name="spotless">spotless</a></div>
573 <div class="doc_text">
574 <p>This utility target, only available when <tt>$(PROJ_OBJ_ROOT)</tt> is not
575 the same as <tt>$(PROJ_SRC_ROOT)</tt>, will completely clean the
576 <tt>$(PROJ_OBJ_ROOT)</tt> directory by removing its content entirely and
577 reconfiguring the directory. This returns the <tt>$(PROJ_OBJ_ROOT)</tt>
578 directory to a completely fresh state. All content in the directory except
579 configured files and top-level makefiles will be lost.</p>
580 <div class="doc_warning"><p>Use with caution.</p></div>
583 <!-- ======================================================================= -->
584 <div class="doc_subsection"><a name="tags">tags</a></div>
585 <div class="doc_text">
586 <p>This target will generate a <tt>TAGS</tt> file in the top-level source
587 directory. It is meant for use with emacs, XEmacs, or ViM. The TAGS file
588 provides an index of symbol definitions so that the editor can jump you to the
589 definition quickly. </p>
592 <!-- ======================================================================= -->
593 <div class="doc_subsection"><a name="uninstall">uninstall</a></div>
594 <div class="doc_text">
595 <p>This target is the opposite of the <tt>install</tt> target. It removes the
596 header, library and executable files from the installation directories. Note
597 that the directories themselves are not removed because it is not guaranteed
598 that LLVM is the only thing installing there (e.g. --prefix=/usr).</p>
601 <!-- *********************************************************************** -->
602 <div class="doc_section"><a name="variables">Variables</a></div>
603 <!-- *********************************************************************** -->
604 <div class="doc_text">
605 <p>Variables are used to tell the LLVM Makefile System what to do and to
606 obtain information from it. Variables are also used internally by the LLVM
607 Makefile System. Variable names that contain only the upper case alphabetic
608 letters and underscore are intended for use by the end user. All other
609 variables are internal to the LLVM Makefile System and should not be relied
610 upon nor modified. The sections below describe how to use the LLVM Makefile
614 <!-- ======================================================================= -->
615 <div class="doc_subsection"><a name="setvars">Control Variables</a></div>
616 <div class="doc_text">
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>
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="DIRS"><tt>DIRS</tt></a></dt>
633 <dd>Specifies a set of directories, usually children of the current
634 directory, that should also be made using the same goal. These directories
635 will be built serially.</dd>
636 <dt><a name="DISABLE_AUTO_DEPENDENCIES"><tt>DISABLE_AUTO_DEPENDENCIES</tt></a></dt>
637 <dd>If set to any value, causes the makefiles to <b>not</b> automatically
638 generate dependencies when running the compiler. Use of this feature is
639 discouraged and it may be removed at a later date.</dd>
640 <dt><a name="DONT_BUILD_RELINKED"><tt>DONT_BUILD_RELINKED</tt></a></dt>
641 <dd>If set to any value, causes a relinked library (.o) not to be built. By
642 default, libraries are built as re-linked since most LLVM libraries are
643 needed in their entirety and re-linked libraries will be linked more quickly
644 than equivalent archive libraries.</dd>
645 <dt><a name="ENABLE_OPTIMIZED"><tt>ENABLE_OPTIMIZED</tt></a></dt>
646 <dd>If set to any value, 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
650 <dt><a name="ENABLE_PROFILING"><tt>ENABLE_PROFILING</tt></a></dt>
651 <dd>If set to any value, 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 any value, causes the build to disable assertions, even if
658 building a release 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
683 <dt><a name="LIBRARYNAME"><tt>LIBRARYNAME</tt></a></dt>
684 <dd>Specify the name of the library to be built. (Required For
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
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
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
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
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
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
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>
767 <!-- ======================================================================= -->
768 <div class="doc_subsection"><a name="overvars">Override Variables</a></div>
769 <div class="doc_text">
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
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>
780 <p>The override variables are given below:</p>
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
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="BZIP2"><tt>BZIP2</tt></a><small>(configured)</small></dt>
792 <dd>The path to the <tt>bzip2</tt> tool.</dd>
793 <dt><a name="CC"><tt>CC</tt></a><small>(configured)</small></dt>
794 <dd>The path to the 'C' compiler.</dd>
795 <dt><a name="CFLAGS"><tt>CFLAGS</tt></a></dt>
796 <dd>Additional flags to be passed to the 'C' compiler.</dd>
797 <dt><a name="CXX"><tt>CXX</tt></a></dt>
798 <dd>Specifies the path to the C++ compiler.</dd>
799 <dt><a name="CXXFLAGS"><tt>CXXFLAGS</tt></a></dt>
800 <dd>Additional flags to be passed to the C++ compiler.</dd>
801 <dt><a name="DATE"><tt>DATE<small>(configured)</small></tt></a></dt>
802 <dd>Specifies the path to the <tt>date</tt> program or any program that can
803 generate the current date and time on its standard output</dd>
804 <dt><a name="DOT"><tt>DOT</tt></a><small>(configured)</small></dt>
805 <dd>Specifies the path to the <tt>dot</tt> tool or <tt>false</tt> if there
807 <dt><a name="ECHO"><tt>ECHO</tt></a><small>(configured)</small></dt>
808 <dd>Specifies the path to the <tt>echo</tt> tool for printing output.</dd>
809 <dt><a name="EXEEXT"><tt>EXEEXT</tt></a><small>(configured)</small></dt>
810 <dd>Provides the extension to be used on executables built by the makefiles.
811 The value may be empty on platforms that do not use file extensions for
812 executables (e.g. Unix).</dd>
813 <dt><a name="INSTALL"><tt>INSTALL</tt></a><small>(configured)</small></dt>
814 <dd>Specifies the path to the <tt>install</tt> tool.</dd>
815 <dt><a name="LDFLAGS"><tt>LDFLAGS</tt></a><small>(configured)</small></dt>
816 <dd>Allows users to specify additional flags to pass to the linker.</dd>
817 <dt><a name="LIBS"><tt>LIBS</tt></a><small>(configured)</small></dt>
818 <dd>The list of libraries that should be linked with each tool.</dd>
819 <dt><a name="LIBTOOL"><tt>LIBTOOL</tt></a><small>(configured)</small></dt>
820 <dd>Specifies the path to the <tt>libtool</tt> tool. This tool is renamed
821 <tt>mklib</tt> by the <tt>configure</tt> script and always located in the
822 <dt><a name="LLVMAS"><tt>LLVMAS</tt></a><small>(defaulted)</small></dt>
823 <dd>Specifies the path to the <tt>llvm-as</tt> tool.</dd>
824 <dt><a name="LLVMGCC"><tt>LLVMGCC</tt></a><small>(defaulted)</small></dt>
825 <dd>Specifies the path to the LLVM version of the GCC 'C' Compiler</dd>
826 <dt><a name="LLVMGXX"><tt>LLVMGXX</tt></a><small>(defaulted)</small></dt>
827 <dd>Specifies the path to the LLVM version of the GCC C++ Compiler</dd>
828 <dt><a name="LLVMLD"><tt>LLVMLD</tt></a><small>(defaulted)</small></dt>
829 <dd>Specifies the path to the LLVM bitcode linker tool</dd>
830 <dt><a name="LLVM_OBJ_ROOT"><tt>LLVM_OBJ_ROOT</tt></a><small>(configured)
832 <dd>Specifies the top directory into which the output of the build is
834 <dt><a name="LLVM_SRC_ROOT"><tt>LLVM_SRC_ROOT</tt></a><small>(configured)
836 <dd>Specifies the top directory in which the sources are found.</dd>
837 <dt><a name="LLVM_TARBALL_NAME"><tt>LLVM_TARBALL_NAME</tt></a>
838 <small>(configured)</small></dt>
839 <dd>Specifies the name of the distribution tarball to create. This is
840 configured from the name of the project and its version number.</dd>
841 <dt><a name="MKDIR"><tt>MKDIR</tt></a><small>(defaulted)</small></dt>
842 <dd>Specifies the path to the <tt>mkdir</tt> tool that creates
844 <dt><a name="PLATFORMSTRIPOPTS"><tt>PLATFORMSTRIPOPTS</tt></a></dt>
845 <dd>The options to provide to the linker to specify that a stripped (no
846 symbols) executable should be built.</dd>
847 <dt><a name="RANLIB"><tt>RANLIB</tt></a><small>(defaulted)</small></dt>
848 <dd>Specifies the path to the <tt>ranlib</tt> tool.</dd>
849 <dt><a name="RM"><tt>RM</tt></a><small>(defaulted)</small></dt>
850 <dd>Specifies the path to the <tt>rm</tt> tool.</dd>
851 <dt><a name="SED"><tt>SED</tt></a><small>(defaulted)</small></dt>
852 <dd>Specifies the path to the <tt>sed</tt> tool.</dd>
853 <dt><a name="SHLIBEXT"><tt>SHLIBEXT</tt></a><small>(configured)</small></dt>
854 <dd>Provides the filename extension to use for shared libraries.</dd>
855 <dt><a name="TBLGEN"><tt>TBLGEN</tt></a><small>(defaulted)</small></dt>
856 <dd>Specifies the path to the <tt>tblgen</tt> tool.</dd>
857 <dt><a name="TAR"><tt>TAR</tt></a><small>(defaulted)</small></dt>
858 <dd>Specifies the path to the <tt>tar</tt> tool.</dd>
859 <dt><a name="ZIP"><tt>ZIP</tt></a><small>(defaulted)</small></dt>
860 <dd>Specifies the path to the <tt>zip</tt> tool.</dd>
864 <!-- ======================================================================= -->
865 <div class="doc_subsection"><a name="getvars">Readable Variables</a></div>
866 <div class="doc_text">
867 <p>Variables listed in the table below can be used by the user's Makefile but
868 should not be changed. Changing the value will generally cause the build to go
869 wrong, so don't do it.</p>
871 <dt><a name="bindir"><tt>bindir</tt></a></dt>
872 <dd>The directory into which executables will ultimately be installed. This
873 value is derived from the <tt>--prefix</tt> option given to
874 <tt>configure</tt>.</dd>
875 <dt><a name="BuildMode"><tt>BuildMode</tt></a></dt>
876 <dd>The name of the type of build being performed: Debug, Release, or
878 <dt><a name="bitcode_libdir"><tt>bytecode_libdir</tt></a></dt>
879 <dd>The directory into which bitcode libraries will ultimately be
880 installed. This value is derived from the <tt>--prefix</tt> option given to
881 <tt>configure</tt>.</dd>
882 <dt><a name="ConfigureScriptFLAGS"><tt>ConfigureScriptFLAGS</tt></a></dt>
883 <dd>Additional flags given to the <tt>configure</tt> script when
885 <dt><a name="DistDir"><tt>DistDir</tt></a></dt>
886 <dd>The <em>current</em> directory for which a distribution copy is being
888 <dt><a name="Echo"><tt>Echo</tt></a></dt>
889 <dd>The LLVM Makefile System output command. This provides the
890 <tt>llvm[n]</tt> prefix and starts with @ so the command itself is not
891 printed by <tt>make</tt>.</dd>
892 <dt><a name="EchoCmd"><tt>EchoCmd</tt></a></dt>
893 <dd> Same as <a href="#Echo"><tt>Echo</tt></a> but without the leading @.
895 <dt><a name="includedir"><tt>includedir</tt></a></dt>
896 <dd>The directory into which include files will ultimately be installed.
897 This value is derived from the <tt>--prefix</tt> option given to
898 <tt>configure</tt>.</dd>
899 <dt><a name="libdir"><tt>libdir</tt></a></dt><dd></dd>
900 <dd>The directory into which native libraries will ultimately be installed.
901 This value is derived from the <tt>--prefix</tt> option given to
902 <tt>configure</tt>.</dd>
903 <dt><a name="LibDir"><tt>LibDir</tt></a></dt>
904 <dd>The configuration specific directory into which libraries are placed
905 before installation.</dd>
906 <dt><a name="MakefileConfig"><tt>MakefileConfig</tt></a></dt>
907 <dd>Full path of the <tt>Makefile.config</tt> file.</dd>
908 <dt><a name="MakefileConfigIn"><tt>MakefileConfigIn</tt></a></dt>
909 <dd>Full path of the <tt>Makefile.config.in</tt> file.</dd>
910 <dt><a name="ObjDir"><tt>ObjDir</tt></a></dt>
911 <dd>The configuration and directory specific directory where build objects
912 (compilation results) are placed.</dd>
913 <dt><a name="SubDirs"><tt>SubDirs</tt></a></dt>
914 <dd>The complete list of sub-directories of the current directory as
915 specified by other variables.</dd>
916 <dt><a name="Sources"><tt>Sources</tt></a></dt>
917 <dd>The complete list of source files.</dd>
918 <dt><a name="sysconfdir"><tt>sysconfdir</tt></a></dt>
919 <dd>The directory into which configuration files will ultimately be
920 installed. This value is derived from the <tt>--prefix</tt> option given to
921 <tt>configure</tt>.</dd>
922 <dt><a name="ToolDir"><tt>ToolDir</tt></a></dt>
923 <dd>The configuration specific directory into which executables are placed
924 before they are installed.</dd>
925 <dt><a name="TopDistDir"><tt>TopDistDir</tt></a></dt>
926 <dd>The top most directory into which the distribution files are copied.
928 <dt><a name="Verb"><tt>Verb</tt></a></dt>
929 <dd>Use this as the first thing on your build script lines to enable or
930 disable verbose mode. It expands to either an @ (quiet mode) or nothing
931 (verbose mode). </dd>
935 <!-- ======================================================================= -->
936 <div class="doc_subsection"><a name="intvars">Internal Variables</a></div>
937 <div class="doc_text">
938 <p>Variables listed below are used by the LLVM Makefile System
939 and considered internal. You should not use these variables under any
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