<ol>
<li><a href="#libraries">Libraries</a>
<ol>
- <li><a href="#Modules">Bytecode Modules</a></li>
+ <li><a href="#BCModules">Bytecode Modules</a></li>
+ <li><a href="#LoadableModules">Loadable Modules</a></li>
</ol>
</li>
<li><a href="#tools">Tools</a>
LIBRARYNAME = mylib
SHARED_LIBRARY = 1
ARCHIVE_LIBRARY = 1
- DONT_BUILT_RELINKED = 1
+ DONT_BUILD_RELINKED = 1
</tt></pre>
<p>says to build a library named "mylib" with both a shared library
(<tt>mylib.so</tt>) and an archive library (<tt>mylib.a</tt>) version but
</div>
<!-- ======================================================================= -->
-<div class="doc_subsubsection"><a name="Modules">Bytecode Modules</a></div>
+<div class="doc_subsubsection"><a name="BCModules">Bytecode Modules</a></div>
<div class="doc_text">
<p>In some situations, it is desireable to build a single bytecode module from
a variety of sources, instead of an archive, shared library, or bytecode
</p>
</div>
+<!-- ======================================================================= -->
+<div class="doc_subsubsection">
+ <a name="LoadableModules">Loadable Modules</a>
+</div>
+<div class="doc_text">
+ <p>In some situations, you need to create a loadable module. Loadable modules
+ can be loaded into programs like <tt>opt</tt> or <tt>llc</tt> to specify
+ additional passes to run or targets to support. Loadable modules are also
+ useful for debugging a pass or providing a pass with another package if that
+ pass can't be included in LLVM.</p>
+ <p>LLVM provides complete support for building such a module. All you need to
+ do is use the LOADABLE_MODULE variable in your Makefile. For example, to
+ build a loadable module named <tt>MyMod</tt> that uses the LLVM libraries
+ <tt>LLVMSupport.a</tt> and <tt>LLVMSystem.a</tt>, you would specify:</p>
+ <pre><tt>
+ LIBRARYNAME := MyMod
+ LOADABLE_MODULE := 1
+ LINK_COMPONENTS := support system
+ </tt></pre>
+ <p>Use of the <tt>LOADABLE_MODULE</tt> facility implies several things:</p>
+ <ol>
+ <li>There will be no "lib" prefix on the module. This differentiates it from
+ a standard shared library of the same name.</li>
+ <li>The <a href="#SHARED_LIBRARY">SHARED_LIBRARY</a> variable is turned
+ on.</li>
+ <li>The <a href="#LINK_LIBS_IN_SHARED">LINK_LIBS_IN_SHARED</a> variable
+ is turned on.</li>
+ <li>The <a href="#DONT_BUILD_RELINKED">DONT_BUILD_RELINKED</a> variable
+ is turned on.</li>
+ </ol>
+ <p>A loadable module is loaded by LLVM via the facilities of libtool's libltdl
+ library which is part of <tt>lib/System</tt> implementation.</p>
+</div>
+
<!-- ======================================================================= -->
<div class="doc_subsection"><a name="tools">Tools</a></div>
<div class="doc_text">
<pre><tt>
TOOLNAME = mytool
USEDLIBS = mylib
- LLVMLIBS = LLVMSupport.a LLVMSystem.a
+ LINK_COMPONENTS = support system
</tt></pre>
<p>says that we are to build a tool name <tt>mytool</tt> and that it requires
three libraries: <tt>mylib</tt>, <tt>LLVMSupport.a</tt> and
<!-- ======================================================================= -->
<div class="doc_subsubsection"><a name="JIT">JIT Tools</a></div>
<div class="doc_text">
- <p>Many tools will want to use the JIT features of LLVM. However, getting the
- right set of libraries to link with is tedious, platform specific, and error
- prone. Additionally, the JIT has special linker switch options that it needs.
- Consequently, to make it easier to build tools that use the JIT, you can
- use a special value for the <tt>LLVMLIBS</tt> variable:</p>
+ <p>Many tools will want to use the JIT features of LLVM. To do this, you
+ simply specify that you want an execution 'engine', and the makefiles will
+ automatically link in the appropriate JIT for the host or an interpreter
+ if none is available:</p>
<pre><tt>
TOOLNAME = my_jit_tool
USEDLIBS = mylib
- LLVMLIBS = JIT
+ LINK_COMPONENTS = engine
</tt></pre>
- <p>Using a value of <tt>JIT</tt> for <tt>LLVMLIBS</tt> tells the makefile
- system to construct a special value for LLVMLIBS that gives the program all
- the LLVM libraries needed to run the JIT. Any additional libraries needed can
- still be specified with <tt>USEDLIBS</tt>. To get a full understanding of how
- this changes the linker command, it is recommended that you:</p>
+ <p>Of course, any additional libraries may be listed as other components. To
+ get a full understanding of how this changes the linker command, it is
+ recommended that you:</p>
<pre><tt>
cd examples/Fibonacci
make VERBOSE=1
</tt></pre>
- <p>By default, using <tt>LLVMLIBS=JIT</tt> will link in enough to support JIT
- code generation for the architecture on which the tool is linked. If you need
- additional target architectures linked in, you may specify them on the command
- line or in your <tt>Makefile</tt>. For example:</p>
- <pre><tt>
- ENABLE_X86_JIT=1
- ENABLE_SPARCV9_JIT=1
- ENALBE_PPC_JIT=1
- </tt></pre>
- <p>will cause the tool to be able to generate code for all three platforms.
- </p>
</div>
<!-- *********************************************************************** -->
<dt><a name="LIBRARYNAME"><tt>LIBRARYNAME</tt></a></dt>
<dd>Specify the name of the library to be built. (Required For
Libraries)</dd>
+ <dt><a name="LINK_COMPONENTS"><tt>LINK_COMPONENTS</tt></a></dt>
+ <dd>When specified for building a tool, the value of this variable will be
+ passed to the <tt>llvm-config</tt> tool to generate a link line for the
+ tool. Unlike <tt>USEDLIBS</tt> and <tt>LLVMLIBS</tt>, not all libraries need
+ to be specified. The <tt>llvm-config</tt> tool will figure out the library
+ dependencies and add any libraries that are needed. The <tt>USEDLIBS</tt>
+ variable can still be used in conjunction with <tt>LINK_COMPONENTS</tt> so
+ that additional project-specific libraries can be linked with the LLVM
+ libraries specified by <tt>LINK_COMPONENTS</tt></dd>
+ <dt><a name="LINK_LIBS_IN_SHARED"><tt>LINK_LIBS_IN_SHARED</tt></a></dt>
+ <dd>By default, shared library linking will ignore any libraries specified
+ with the <a href="LLVMLIBS">LLVMLIBS</a> or <a href="USEDLIBS">USEDLIBS</a>.
+ This prevents shared libs from including things that will be in the LLVM
+ tool the shared library will be loaded into. However, sometimes it is useful
+ to link certain libraries into your shared library and this option enables
+ that feature.</dd>
<dt><a name="LLVMLIBS"><tt>LLVMLIBS</tt></a></dt>
<dd>Specifies the set of libraries from the LLVM $(ObjDir) that will be
linked into the tool or library.</dd>
module can be specified in conjunction with other kinds of library builds
or by itself. It constructs from the sources a single linked bytecode
file.</dd>
+ <dt><a name="NO_INSTALL"><tt>NO_INSTALL</tt></a></dt>
+ <dd>Specifies that the build products of the directory should not be
+ installed but should be built even if the <tt>install</tt> target is given.
+ This is handy for directories that build libraries or tools that are only
+ used as part of the build process, such as code generators (e.g.
+ <tt>tblgen</tt>).</dd>
<dt><a name="OPTIONAL_DIRS"><tt>OPTIONAL_DIRS</tt></a></dt>
<dd>Specify a set of directories that may be built, if they exist, but its
not an error for them not to exist.</dd>
executables (e.g. Unix).</dd>
<dt><a name="FLEX"><tt>FLEX</tt></a><small>(configured)</small></dt>
<dd>Specifies the path to the <tt>flex</tt> tool.</dd>
- <dt><a name="GCCLD"><tt>GCCLD</tt></a><small>(defaulted)</small></dt>
- <dd>Specifies the path to the <tt>gccld</tt> tool.</dd>
<dt><a name="INSTALL"><tt>INSTALL</tt></a><small>(configured)</small></dt>
<dd>Specifies the path to the <tt>install</tt> tool.</dd>
<dt><a name="LDFLAGS"><tt>LDFLAGS</tt></a><small>(configured)</small></dt>
<dd>Specifies the path to the LLVM version of the GCC 'C' Compiler</dd>
<dt><a name="LLVMGXX"><tt>LLVMGXX</tt></a><small>(defaulted)</small></dt>
<dd>Specifies the path to the LLVM version of the GCC C++ Compiler</dd>
+ <dt><a name="LLVMLD"><tt>LLVMLD</tt></a><small>(defaulted)</small></dt>
+ <dd>Specifies the path to the LLVM bytecode linker tool</dd>
<dt><a name="LLVM_OBJ_ROOT"><tt>LLVM_OBJ_ROOT</tt></a><small>(configured)
</small></dt>
<dd>Specifies the top directory into which the output of the build is