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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">Bytecode 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">Bytecode Modules</a></div>
264 <div class="doc_text">
265 <p>In some situations, it is desireable to build a single bytecode module from
266 a variety of sources, instead of an archive, shared library, or bytecode
267 library. Bytecode 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 bytecode modules
277 derived from the sources. The example will also build a bytecode archive
278 containing a bytecode 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 USEDLIBS := LLVMSupport.a LLVMSystem.a
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 LLVMLIBS = LLVMSupport.a LLVMSystem.a
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. However, getting the
356 right set of libraries to link with is tedious, platform specific, and error
357 prone. Additionally, the JIT has special linker switch options that it needs.
358 Consequently, to make it easier to build tools that use the JIT, you can
359 use a special value for the <tt>LLVMLIBS</tt> variable:</p>
361 TOOLNAME = my_jit_tool
365 <p>Using a value of <tt>JIT</tt> for <tt>LLVMLIBS</tt> tells the makefile
366 system to construct a special value for LLVMLIBS that gives the program all
367 the LLVM libraries needed to run the JIT. Any additional libraries needed can
368 still be specified with <tt>USEDLIBS</tt>. To get a full understanding of how
369 this changes the linker command, it is recommended that you:</p>
371 cd examples/Fibonacci
374 <p>By default, using <tt>LLVMLIBS=JIT</tt> will link in enough to support JIT
375 code generation for the architecture on which the tool is linked. If you need
376 additional target architectures linked in, you may specify them on the command
377 line or in your <tt>Makefile</tt>. For example:</p>
383 <p>will cause the tool to be able to generate code for all three platforms.
387 <!-- *********************************************************************** -->
388 <div class="doc_section"><a name="targets">Targets Supported</a></div>
389 <!-- *********************************************************************** -->
391 <div class="doc_text">
392 <p>This section describes each of the targets that can be built using the LLVM
393 Makefile system. Any target can be invoked from any directory but not all are
394 applicable to a given directory (e.g. "check", "dist" and "install" will
395 always operate as if invoked from the top level directory).</p>
397 <table style="text-align:left">
399 <th>Target Name</th><th>Implied Targets</th><th>Target Description</th>
401 <tr><td><a href="#all"><tt>all</tt></a></td><td></td>
402 <td>Compile the software recursively. Default target.
404 <tr><td><a href="#all-local"><tt>all-local</tt></a></td><td></td>
405 <td>Compile the software in the local directory only.
407 <tr><td><a href="#check"><tt>check</tt></a></td><td></td>
408 <td>Change to the <tt>test</tt> directory in a project and run the
411 <tr><td><a href="#check-local"><tt>check-local</tt></a></td><td></td>
412 <td>Run a local test suite. Generally this is only defined in the
413 <tt>Makefile</tt> of the project's <tt>test</tt> directory.
415 <tr><td><a href="#clean"><tt>clean</tt></a></td><td></td>
416 <td>Remove built objects recursively.
418 <tr><td><a href="#clean-local"><tt>clean-local</tt></a></td><td></td>
419 <td>Remove built objects from the local directory only.
421 <tr><td><a href="#dist"><tt>dist</tt></a></td><td>all</td>
422 <td>Prepare a source distribution tarball.
424 <tr><td><a href="#dist-check"><tt>dist-check</tt></a></td><td>all</td>
425 <td>Prepare a source distribution tarball and check that it builds.
427 <tr><td><a href="#dist-clean"><tt>dist-clean</tt></a></td><td>clean</td>
428 <td>Clean source distribution tarball temporary files.
430 <tr><td><a href="#install"><tt>install</tt></a></td><td>all</td>
431 <td>Copy built objects to installation directory.
433 <tr><td><a href="#preconditions"><tt>preconditions</tt></a></td><td>all</td>
434 <td>Check to make sure configuration and makefiles are up to date.
436 <tr><td><a href="#printvars"><tt>printvars</tt></a></td><td>all</td>
437 <td>Prints variables defined by the makefile system (for debugging).
439 <tr><td><a href="#tags"><tt>tags</tt></a></td><td></td>
440 <td>Make C and C++ tags files for emacs and vi.
442 <tr><td><a href="#uninstall"><tt>uninstall</tt></a></td><td></td>
443 <td>Remove built objects from installation directory.
448 <!-- ======================================================================= -->
449 <div class="doc_subsection"><a name="all">all (default)</a></div>
450 <div class="doc_text">
451 <p>When you invoke <tt>make</tt> with no arguments, you are implicitly
452 instructing it to seek the "all" target (goal). This target is used for
453 building the software recursively and will do different things in different
454 directories. For example, in a <tt>lib</tt> directory, the "all" target will
455 compile source files and generate libraries. But, in a <tt>tools</tt>
456 directory, it will link libraries and generate executables.</p>
459 <!-- ======================================================================= -->
460 <div class="doc_subsection"><a name="all-local">all-local</a></div>
461 <div class="doc_text">
462 <p>This target is the same as <a href="#all">all</a> but it operates only on
463 the current directory instead of recursively.</p>
466 <!-- ======================================================================= -->
467 <div class="doc_subsection"><a name="check">check</a></div>
468 <div class="doc_text">
469 <p>This target can be invoked from anywhere within a project's directories
470 but always invokes the <a href="#check-local"><tt>check-local</tt></a> target
471 in the project's <tt>test</tt> directory, if it exists and has a
472 <tt>Makefile</tt>. A warning is produced otherwise. If
473 <a href="#TESTSUITE"><tt>TESTSUITE</tt></a> is defined on the <tt>make</tt>
474 command line, it will be passed down to the invocation of
475 <tt>make check-local</tt> in the <tt>test</tt> directory. The intended usage
476 for this is to assist in running specific suites of tests. If
477 <tt>TESTSUITE</tt> is not set, the implementation of <tt>check-local</tt>
478 should run all normal tests. It is up to the project to define what
479 different values for <tt>TESTSUTE</tt> will do. See the
480 <a href="TestingGuide.html">TestingGuide</a> for further details.</p>
483 <!-- ======================================================================= -->
484 <div class="doc_subsection"><a name="check-local">check-local</a></div>
485 <div class="doc_text">
486 <p>This target should be implemented by the <tt>Makefile</tt> in the project's
487 <tt>test</tt> directory. It is invoked by the <tt>check</tt> target elsewhere.
488 Each project is free to define the actions of <tt>check-local</tt> as
489 appropriate for that project. The LLVM project itself uses dejagnu to run a
490 suite of feature and regresson tests. Other projects may choose to use
491 dejagnu or any other testing mechanism.</p>
494 <!-- ======================================================================= -->
495 <div class="doc_subsection"><a name="clean">clean</a></div>
496 <div class="doc_text">
497 <p>This target cleans the build directory, recursively removing all things
498 that the Makefile builds. The cleaning rules have been made guarded so they
499 shouldn't go awry (via <tt>rm -f $(UNSET_VARIABLE)/*</tt> which will attempt
500 to erase the entire directory structure.</p>
503 <!-- ======================================================================= -->
504 <div class="doc_subsection"><a name="clean-local">clean-local</a></div>
505 <div class="doc_text">
506 <p>This target does the same thing as <tt>clean</tt> but only for the current
507 (local) directory.</p>
510 <!-- ======================================================================= -->
511 <div class="doc_subsection"><a name="dist">dist</a></div>
512 <div class="doc_text">
513 <p>This target builds a distribution tarball. It first builds the entire
514 project using the <tt>all</tt> target and then tars up the necessary files and
515 compresses it. The generated tarball is sufficient for a casual source
516 distribution, but probably not for a release (see <tt>dist-check</tt>).</p>
519 <!-- ======================================================================= -->
520 <div class="doc_subsection"><a name="dist-check">dist-check</a></div>
521 <div class="doc_text">
522 <p>This target does the same thing as the <tt>dist</tt> target but also checks
523 the distribution tarball. The check is made by unpacking the tarball to a new
524 directory, configuring it, building it, installing it, and then verifying that
525 the installation results are correct (by comparing to the original build).
526 This target can take a long time to run but should be done before a release
527 goes out to make sure that the distributed tarball can actually be built into
528 a working release.</p>
531 <!-- ======================================================================= -->
532 <div class="doc_subsection"><a name="dist-clean">dist-clean</a></div>
533 <div class="doc_text">
534 <p>This is a special form of the <tt>clean</tt> clean target. It performs a
535 normal <tt>clean</tt> but also removes things pertaining to building the
539 <!-- ======================================================================= -->
540 <div class="doc_subsection"><a name="install">install</a></div>
541 <div class="doc_text">
542 <p>This target finalizes shared objects and executables and copies all
543 libraries, headers, executables and documentation to the directory given
544 with the <tt>--prefix</tt> option to <tt>configure</tt>. When completed,
545 the prefix directory will have everything needed to <b>use</b> LLVM. </p>
546 <p>The LLVM makefiles can generate complete <b>internal</b> documentation
547 for all the classes by using <tt>doxygen</tt>. By default, this feature is
548 <b>not</b> enabled because it takes a long time and generates a massive
549 amount of data (>100MB). If you want this feature, you must configure LLVM
550 with the --enable-doxygen switch and ensure that a modern version of doxygen
551 (1.3.7 or later) is available in your <tt>PATH</tt>. You can download
553 <a href="http://www.stack.nl/~dimitri/doxygen/download.html#latestsrc">
557 <!-- ======================================================================= -->
558 <div class="doc_subsection"><a name="preconditions">preconditions</a></div>
559 <div class="doc_text">
560 <p>This utility target checks to see if the <tt>Makefile</tt> in the object
561 directory is older than the <tt>Makefile</tt> in the source directory and
562 copies it if so. It also reruns the <tt>configure</tt> script if that needs to
563 be done and rebuilds the <tt>Makefile.config</tt> file similarly. Users may
564 overload this target to ensure that sanity checks are run <em>before</em> any
565 building of targets as all the targets depend on <tt>preconditions</tt>.</p>
568 <!-- ======================================================================= -->
569 <div class="doc_subsection"><a name="printvars">printvars</a></div>
570 <div class="doc_text">
571 <p>This utility target just causes the LLVM makefiles to print out some of
572 the makefile variables so that you can double check how things are set. </p>
575 <!-- ======================================================================= -->
576 <div class="doc_subsection"><a name="reconfigure">reconfigure</a></div>
577 <div class="doc_text">
578 <p>This utility target will force a reconfigure of LLVM or your project. It
579 simply runs <tt>$(PROJ_OBJ_ROOT)/config.status --recheck</tt> to rerun the
580 configuration tests and rebuild the configured files. This isn't generally
581 useful as the makefiles will reconfigure themselves whenever its necessary.
585 <!-- ======================================================================= -->
586 <div class="doc_subsection"><a name="spotless">spotless</a></div>
587 <div class="doc_text">
588 <p>This utility target, only available when <tt>$(PROJ_OBJ_ROOT)</tt> is not
589 the same as <tt>$(PROJ_SRC_ROOT)</tt>, will completely clean the
590 <tt>$(PROJ_OBJ_ROOT)</tt> directory by removing its content entirely and
591 reconfiguring the directory. This returns the <tt>$(PROJ_OBJ_ROOT)</tt>
592 directory to a completely fresh state. All content in the directory except
593 configured files and top-level makefiles will be lost.</p>
594 <div class="doc_warning"><p>Use with caution.</p></div>
597 <!-- ======================================================================= -->
598 <div class="doc_subsection"><a name="tags">tags</a></div>
599 <div class="doc_text">
600 <p>This target will generate a <tt>TAGS</tt> file in the top-level source
601 directory. It is meant for use with emacs, XEmacs, or ViM. The TAGS file
602 provides an index of symbol definitions so that the editor can jump you to the
603 definition quickly. </p>
606 <!-- ======================================================================= -->
607 <div class="doc_subsection"><a name="uninstall">uninstall</a></div>
608 <div class="doc_text">
609 <p>This target is the opposite of the <tt>install</tt> target. It removes the
610 header, library and executable files from the installation directories. Note
611 that the directories themselves are not removed because it is not guaranteed
612 that LLVM is the only thing installing there (e.g. --prefix=/usr).</p>
615 <!-- *********************************************************************** -->
616 <div class="doc_section"><a name="variables">Variables</a></div>
617 <!-- *********************************************************************** -->
618 <div class="doc_text">
619 <p>Variables are used to tell the LLVM Makefile System what to do and to
620 obtain information from it. Variables are also used internally by the LLVM
621 Makefile System. Variable names that contain only the upper case alphabetic
622 letters and underscore are intended for use by the end user. All other
623 variables are internal to the LLVM Makefile System and should not be relied
624 upon nor modified. The sections below describe how to use the LLVM Makefile
628 <!-- ======================================================================= -->
629 <div class="doc_subsection"><a name="setvars">Control Variables</a></div>
630 <div class="doc_text">
631 <p>Variables listed in the table below should be set <em>before</em> the
632 inclusion of <a href="#Makefile.common"><tt>$(LEVEL)/Makefile.common</tt></a>.
633 These variables provide input to the LLVM make system that tell it what to do
634 for the current directory.</p>
636 <dt><a name="BUILD_ARCHIVE"><tt>BUILD_ARCHIVE</tt></a></dt>
637 <dd>If set to any value, causes an archive (.a) library to be built.</dd>
638 <dt><a name="BUILT_SOURCES"><tt>BUILT_SOURCES</tt></a></dt>
639 <dd>Specifies a set of source files that are generated from other source
640 files. These sources will be built before any other target processing to
641 ensure they are present.</dd>
642 <dt><a name="BYTECODE_LIBRARY"><tt>BYTECODE_LIBRARY</tt></a></dt>
643 <dd>If set to any value, causes a bytecode library (.bc) to be built.</dd>
644 <dt><a name="CONFIG_FILES"><tt>CONFIG_FILES</tt></a></dt>
645 <dd>Specifies a set of configuration files to be installed.</dd>
646 <dt><a name="DIRS"><tt>DIRS</tt></a></dt>
647 <dd>Specifies a set of directories, usually children of the current
648 directory, that should also be made using the same goal. These directories
649 will be built serially.</dd>
650 <dt><a name="DISABLE_AUTO_DEPENDENCIES"><tt>DISABLE_AUTO_DEPENDENCIES</tt></a></dt>
651 <dd>If set to any value, causes the makefiles to <b>not</b> automatically
652 generate dependencies when running the compiler. Use of this feature is
653 discouraged and it may be removed at a later date.</dd>
654 <dt><a name="DONT_BUILD_RELINKED"><tt>DONT_BUILD_RELINKED</tt></a></dt>
655 <dd>If set to any value, causes a relinked library (.o) not to be built. By
656 default, libraries are built as re-linked since most LLVM libraries are
657 needed in their entirety and re-linked libraries will be linked more quickly
658 than equivalent archive libraries.</dd>
659 <dt><a name="ENABLE_OPTIMIZED"><tt>ENABLE_OPTIMIZED</tt></a></dt>
660 <dd>If set to any value, causes the build to generate optimized objects,
661 libraries and executables. This alters the flags specified to the compilers
662 and linkers. Generally debugging won't be a fun experience with an optimized
664 <dt><a name="ENABLE_PROFILING"><tt>ENABLE_PROFILING</tt></a></dt>
665 <dd>If set to any value, causes the build to generate both optimized and
666 profiled objects, libraries and executables. This alters the flags specified
667 to the compilers and linkers to ensure that profile data can be collected
668 from the tools built. Use the <tt>gprof</tt> tool to analyze the output from
669 the profiled tools (<tt>gmon.out</tt>).</dd>
670 <dt><a name="DISABLE_ASSERTIONS"><tt>DISABLE_ASSERTIONS</tt></a></dt>
671 <dd>If set to any value, causes the build to disable assertions, even if
672 building a release or profile build. This will exclude all assertion check
673 code from the build. LLVM will execute faster, but with little help when
674 things go wrong.</dd>
675 <dt><a name="EXPERIMENTAL_DIRS"><tt>EXPERIMENTAL_DIRS</tt></a></dt>
676 <dd>Specify a set of directories that should be built, but if they fail, it
677 should not cause the build to fail. Note that this should only be used
678 temporarily while code is being written.</dd>
679 <dt><a name="EXPORTED_SYMBOL_FILE"><tt>EXPORTED_SYMBOL_FILE</tt></a></dt>
680 <dd>Specifies the name of a single file that contains a list of the
681 symbols to be exported by the linker. One symbol per line.</dd>
682 <dt><a name="EXPORTED_SYMBOL_LIST"><tt>EXPORTED_SYMBOL_LIST</tt></a></dt>
683 <dd>Specifies a set of symbols to be exported by the linker.</dd>
684 <dt><a name="EXTRA_DIST"><tt>EXTRA_DIST</tt></a></dt>
685 <dd>Specifies additional files that should be distributed with LLVM. All
686 source files, all built sources, all Makefiles, and most documentation files
687 will be automatically distributed. Use this variable to distribute any
688 files that are not automatically distributed.</dd>
689 <dt><a name="KEEP_SYMBOLS"><tt>KEEP_SYMBOLS</tt></a></dt>
690 <dd>If set to any value, specifies that when linking executables the
691 makefiles should retain debug symbols in the executable. Normally, symbols
692 are stripped from the executable.</dd>
693 <dt><a name="LEVEL"><tt>LEVEL</tt></a><small>(required)</small></dt>
694 <dd>Specify the level of nesting from the top level. This variable must be
695 set in each makefile as it is used to find the top level and thus the other
697 <dt><a name="LIBRARYNAME"><tt>LIBRARYNAME</tt></a></dt>
698 <dd>Specify the name of the library to be built. (Required For
700 <dt><a name="LINK_LIBS_IN_SHARED"><tt>LINK_LIBS_IN_SHARED</tt></a></dt>
701 <dd>By default, shared library linking will ignore any libraries specified
702 with the <a href="LLVMLIBS">LLVMLIBS</a> or <a href="USEDLIBS">USEDLIBS</a>.
703 This prevents shared libs from including things that will be in the LLVM
704 tool the shared library will be loaded into. However, sometimes it is useful
705 to link certain libraries into your shared library and this option enables
707 <dt><a name="LLVMLIBS"><tt>LLVMLIBS</tt></a></dt>
708 <dd>Specifies the set of libraries from the LLVM $(ObjDir) that will be
709 linked into the tool or library.</dd>
710 <dt><a name="LOADABLE_MODULE"><tt>LOADABLE_MODULE</tt></a></dt>
711 <dd>If set to any value, causes the shared library being built to also be
712 a loadable module. Loadable modules can be opened with the dlopen() function
713 and searched with dlsym (or the operating system's equivalent). Note that
714 setting this variable without also setting <tt>SHARED_LIBRARY</tt> will have
716 <dt><a name="MODULE_NAME"><tt>MODULE_NAME</tt></a></dt>
717 <dd>Specifies the name of a bytecode module to be created. A bytecode
718 module can be specified in conjunction with other kinds of library builds
719 or by itself. It constructs from the sources a single linked bytecode
721 <dt><a name="OPTIONAL_DIRS"><tt>OPTIONAL_DIRS</tt></a></dt>
722 <dd>Specify a set of directories that may be built, if they exist, but its
723 not an error for them not to exist.</dd>
724 <dt><a name="PARALLEL_DIRS"><tt>PARALLEL_DIRS</tt></a></dt>
725 <dd>Specify a set of directories to build recursively and in parallel if
726 the -j option was used with <tt>make</tt>.</dd>
727 <dt><a name="SHARED_LIBRARY"><tt>SHARED_LIBRARY</tt></a></dt>
728 <dd>If set to any value, causes a shared library (.so) to be built in
729 addition to any other kinds of libraries. Note that this option will cause
730 all source files to be built twice: once with options for position
731 independent code and once without. Use it only where you really need a
733 <dt><a name="SOURCES"><tt>SOURCES</tt><small>(optional)</small></a></dt>
734 <dd>Specifies the list of source files in the current directory to be
735 built. Source files of any type may be specified (programs, documentation,
736 config files, etc.). If not specified, the makefile system will infer the
737 set of source files from the files present in the current directory.</dd>
738 <dt><a name="SUFFIXES"><tt>SUFFIXES</tt></a></dt>
739 <dd>Specifies a set of filename suffixes that occur in suffix match rules.
740 Only set this if your local <tt>Makefile</tt> specifies additional suffix
742 <dt><a name="TARGET"><tt>TARGET</tt></a></dt>
743 <dd>Specifies the name of the LLVM code generation target that the
744 current directory builds. Setting this variable enables additional rules to
745 build <tt>.inc</tt> files from <tt>.td</tt> files. </dd>
746 <dt><a name="TESTSUITE"><tt>TESTSUITE</tt></a></dt>
747 <dd>Specifies the directory of tests to run in <tt>llvm/test</tt>.</dd>
748 <dt><a name="TOOLNAME"><tt>TOOLNAME</tt></a></dt>
749 <dd>Specifies the name of the tool that the current directory should
751 <dt><a name="TOOL_VERBOSE"><tt>TOOL_VERBOSE</tt></a></dt>
752 <dd>Implies VERBOSE and also tells each tool invoked to be verbose. This is
753 handy when you're trying to see the sub-tools invoked by each tool invoked
754 by the makefile. For example, this will pass <tt>-v</tt> to the GCC
755 compilers which causes it to print out the command lines it uses to invoke
756 sub-tools (compiler, assembler, linker).</dd>
757 <dt><a name="USEDLIBS"><tt>USEDLIBS</tt></a></dt>
758 <dd>Specifies the list of project libraries that will be linked into the
759 tool or library.</dd>
760 <dt><a name="VERBOSE"><tt>VERBOSE</tt></a></dt>
761 <dd>Tells the Makefile system to produce detailed output of what it is doing
762 instead of just summary comments. This will generate a LOT of output.</dd>
766 <!-- ======================================================================= -->
767 <div class="doc_subsection"><a name="overvars">Override Variables</a></div>
768 <div class="doc_text">
769 <p>Override variables can be used to override the default
770 values provided by the LLVM makefile system. These variables can be set in
773 <li>In the environment (e.g. setenv, export) -- not recommended.</li>
774 <li>On the <tt>make</tt> command line -- recommended.</li>
775 <li>On the <tt>configure</tt> command line</li>
776 <li>In the Makefile (only <em>after</em> the inclusion of <a
777 href="#Makefile.common"><tt>$(LEVEL)/Makefile.common</tt></a>).</li>
779 <p>The override variables are given below:</p>
781 <dt><a name="AR"><tt>AR</tt></a> <small>(defaulted)</small></dt>
782 <dd>Specifies the path to the <tt>ar</tt> tool.</dd>
783 <dt><a name="BISON"><tt>BISON</tt></a><small>(configured)</small></dt>
784 <dd>Specifies the path to the <tt>bison</tt> tool.</dd>
785 <dt><a name="PROJ_OBJ_DIR"><tt>PROJ_OBJ_DIR</tt></a></dt>
786 <dd>The directory into which the products of build rules will be placed.
787 This might be the same as
788 <a href="#PROJ_SRC_DIR"><tt>PROJ_SRC_DIR</tt></a> but typically is
790 <dt><a name="PROJ_SRC_DIR"><tt>PROJ_SRC_DIR</tt></a></dt>
791 <dd>The directory which contains the source files to be built.</dd>
792 <dt><a name="BZIP2"><tt>BZIP2</tt></a><small>(configured)</small></dt>
793 <dd>The path to the <tt>bzip2</tt> tool.</dd>
794 <dt><a name="CC"><tt>CC</tt></a><small>(configured)</small></dt>
795 <dd>The path to the 'C' compiler.</dd>
796 <dt><a name="CFLAGS"><tt>CFLAGS</tt></a></dt>
797 <dd>Additional flags to be passed to the 'C' compiler.</dd>
798 <dt><a name="CXX"><tt>CXX</tt></a></dt>
799 <dd>Specifies the path to the C++ compiler.</dd>
800 <dt><a name="CXXFLAGS"><tt>CXXFLAGS</tt></a></dt>
801 <dd>Additional flags to be passed to the C++ compiler.</dd>
802 <dt><a name="DATE"><tt>DATE<small>(configured)</small></tt></a></dt>
803 <dd>Specifies the path to the <tt>date</tt> program or any program that can
804 generate the current date and time on its standard output</dd>
805 <dt><a name="DOT"><tt>DOT</tt></a><small>(configured)</small></dt>
806 <dd>Specifies the path to the <tt>dot</tt> tool or <tt>false</tt> if there
808 <dt><a name="ECHO"><tt>ECHO</tt></a><small>(configured)</small></dt>
809 <dd>Specifies the path to the <tt>echo</tt> tool for printing output.</dd>
810 <dt><a name="ETAGS"><tt>ETAGS</tt></a><small>(configured)</small></dt>
811 <dd>Specifies the path to the <tt>etags</tt> tool.</dd>
812 <dt><a name="ETAGSFLAGS"><tt>ETAGSFLAGS</tt></a><small>(configured)</small>
814 <dd>Provides flags to be passed to the <tt>etags</tt> tool.</dd>
815 <dt><a name="EXEEXT"><tt>EXEEXT</tt></a><small>(configured)</small></dt>
816 <dd>Provides the extension to be used on executables built by the makefiles.
817 The value may be empty on platforms that do not use file extensions for
818 executables (e.g. Unix).</dd>
819 <dt><a name="FLEX"><tt>FLEX</tt></a><small>(configured)</small></dt>
820 <dd>Specifies the path to the <tt>flex</tt> tool.</dd>
821 <dt><a name="GCCLD"><tt>GCCLD</tt></a><small>(defaulted)</small></dt>
822 <dd>Specifies the path to the <tt>gccld</tt> tool.</dd>
823 <dt><a name="INSTALL"><tt>INSTALL</tt></a><small>(configured)</small></dt>
824 <dd>Specifies the path to the <tt>install</tt> tool.</dd>
825 <dt><a name="LDFLAGS"><tt>LDFLAGS</tt></a><small>(configured)</small></dt>
826 <dd>Allows users to specify additional flags to pass to the linker.</dd>
827 <dt><a name="LIBS"><tt>LIBS</tt></a><small>(configured)</small></dt>
828 <dd>The list of libraries that should be linked with each tool.</dd>
829 <dt><a name="LIBTOOL"><tt>LIBTOOL</tt></a><small>(configured)</small></dt>
830 <dd>Specifies the path to the <tt>libtool</tt> tool. This tool is renamed
831 <tt>mklib</tt> by the <tt>configure</tt> script and always located in the
832 <dt><a name="LLVMAS"><tt>LLVMAS</tt></a><small>(defaulted)</small></dt>
833 <dd>Specifies the path to the <tt>llvm-as</tt> tool.</dd>
834 <dt><a name="LLVMGCC"><tt>LLVMGCC</tt></a><small>(defaulted)</small></dt>
835 <dd>Specifies the path to the LLVM version of the GCC 'C' Compiler</dd>
836 <dt><a name="LLVMGXX"><tt>LLVMGXX</tt></a><small>(defaulted)</small></dt>
837 <dd>Specifies the path to the LLVM version of the GCC C++ Compiler</dd>
838 <dt><a name="LLVM_OBJ_ROOT"><tt>LLVM_OBJ_ROOT</tt></a><small>(configured)
840 <dd>Specifies the top directory into which the output of the build is
842 <dt><a name="LLVM_SRC_ROOT"><tt>LLVM_SRC_ROOT</tt></a><small>(configured)
844 <dd>Specifies the top directory in which the sources are found.</dd>
845 <dt><a name="LLVM_TARBALL_NAME"><tt>LLVM_TARBALL_NAME</tt></a>
846 <small>(configured)</small></dt>
847 <dd>Specifies the name of the distribution tarball to create. This is
848 configured from the name of the project and its version number.</dd>
849 <dt><a name="MKDIR"><tt>MKDIR</tt></a><small>(defaulted)</small></dt>
850 <dd>Specifies the path to the <tt>mkdir</tt> tool that creates
852 <dt><a name="PLATFORMSTRIPOPTS"><tt>PLATFORMSTRIPOPTS</tt></a></dt>
853 <dd>The options to provide to the linker to specify that a stripped (no
854 symbols) executable should be built.</dd>
855 <dt><a name="RANLIB"><tt>RANLIB</tt></a><small>(defaulted)</small></dt>
856 <dd>Specifies the path to the <tt>ranlib</tt> tool.</dd>
857 <dt><a name="RM"><tt>RM</tt></a><small>(defaulted)</small></dt>
858 <dd>Specifies the path to the <tt>rm</tt> tool.</dd>
859 <dt><a name="SED"><tt>SED</tt></a><small>(defaulted)</small></dt>
860 <dd>Specifies the path to the <tt>sed</tt> tool.</dd>
861 <dt><a name="SHLIBEXT"><tt>SHLIBEXT</tt></a><small>(configured)</small></dt>
862 <dd>Provides the filename extension to use for shared libraries.</dd>
863 <dt><a name="TBLGEN"><tt>TBLGEN</tt></a><small>(defaulted)</small></dt>
864 <dd>Specifies the path to the <tt>tblgen</tt> tool.</dd>
865 <dt><a name="TAR"><tt>TAR</tt></a><small>(defaulted)</small></dt>
866 <dd>Specifies the path to the <tt>tar</tt> tool.</dd>
867 <dt><a name="ZIP"><tt>ZIP</tt></a><small>(defaulted)</small></dt>
868 <dd>Specifies the path to the <tt>zip</tt> tool.</dd>
872 <!-- ======================================================================= -->
873 <div class="doc_subsection"><a name="getvars">Readable Variables</a></div>
874 <div class="doc_text">
875 <p>Variables listed in the table below can be used by the user's Makefile but
876 should not be changed. Changing the value will generally cause the build to go
877 wrong, so don't do it.</p>
879 <dt><a name="bindir"><tt>bindir</tt></a></dt>
880 <dd>The directory into which executables will ultimately be installed. This
881 value is derived from the <tt>--prefix</tt> option given to
882 <tt>configure</tt>.</dd>
883 <dt><a name="BuildMode"><tt>BuildMode</tt></a></dt>
884 <dd>The name of the type of build being performed: Debug, Release, or
886 <dt><a name="bytecode_libdir"><tt>bytecode_libdir</tt></a></dt>
887 <dd>The directory into which bytecode libraries will ultimately be
888 installed. This value is derived from the <tt>--prefix</tt> option given to
889 <tt>configure</tt>.</dd>
890 <dt><a name="ConfigureScriptFLAGS"><tt>ConfigureScriptFLAGS</tt></a></dt>
891 <dd>Additional flags given to the <tt>configure</tt> script when
893 <dt><a name="DistDir"><tt>DistDir</tt></a></dt>
894 <dd>The <em>current</em> directory for which a distribution copy is being
896 <dt><a name="Echo"><tt>Echo</tt></a></dt>
897 <dd>The LLVM Makefile System output command. This provides the
898 <tt>llvm[n]</tt> prefix and starts with @ so the command itself is not
899 printed by <tt>make</tt>.</dd>
900 <dt><a name="EchoCmd"><tt>EchoCmd</tt></a></dt>
901 <dd> Same as <a href="#Echo"><tt>Echo</tt></a> but without the leading @.
903 <dt><a name="includedir"><tt>includedir</tt></a></dt>
904 <dd>The directory into which include files will ultimately be installed.
905 This value is derived from the <tt>--prefix</tt> option given to
906 <tt>configure</tt>.</dd>
907 <dt><a name="libdir"><tt>libdir</tt></a></dt><dd></dd>
908 <dd>The directory into which native libraries will ultimately be installed.
909 This value is derived from the <tt>--prefix</tt> option given to
910 <tt>configure</tt>.</dd>
911 <dt><a name="LibDir"><tt>LibDir</tt></a></dt>
912 <dd>The configuration specific directory into which libraries are placed
913 before installation.</dd>
914 <dt><a name="MakefileConfig"><tt>MakefileConfig</tt></a></dt>
915 <dd>Full path of the <tt>Makefile.config</tt> file.</dd>
916 <dt><a name="MakefileConfigIn"><tt>MakefileConfigIn</tt></a></dt>
917 <dd>Full path of the <tt>Makefile.config.in</tt> file.</dd>
918 <dt><a name="ObjDir"><tt>ObjDir</tt></a></dt>
919 <dd>The configuration and directory specific directory where build objects
920 (compilation results) are placed.</dd>
921 <dt><a name="SubDirs"><tt>SubDirs</tt></a></dt>
922 <dd>The complete list of sub-directories of the current directory as
923 specified by other variables.</dd>
924 <dt><a name="Sources"><tt>Sources</tt></a></dt>
925 <dd>The complete list of source files.</dd>
926 <dt><a name="sysconfdir"><tt>sysconfdir</tt></a></dt>
927 <dd>The directory into which configuration files will ultimately be
928 installed. This value is derived from the <tt>--prefix</tt> option given to
929 <tt>configure</tt>.</dd>
930 <dt><a name="ToolDir"><tt>ToolDir</tt></a></dt>
931 <dd>The configuration specific directory into which executables are placed
932 before they are installed.</dd>
933 <dt><a name="TopDistDir"><tt>TopDistDir</tt></a></dt>
934 <dd>The top most directory into which the distribution files are copied.
936 <dt><a name="Verb"><tt>Verb</tt></a></dt>
937 <dd>Use this as the first thing on your build script lines to enable or
938 disable verbose mode. It expands to either an @ (quiet mode) or nothing
939 (verbose mode). </dd>
943 <!-- ======================================================================= -->
944 <div class="doc_subsection"><a name="intvars">Internal Variables</a></div>
945 <div class="doc_text">
946 <p>Variables listed below are used by the LLVM Makefile System
947 and considered internal. You should not use these variables under any
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