docs/Packaging.html - platform/external/llvm - Gitiles

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   <title>Advice on Packaging LLVM</title>
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 <div class="doc_title">Advice on Packaging LLVM</div>
 <ol>
   <li><a href="#overview">Overview</a></li>
   <li><a href="#compilation">Compile Flags</a></li>
   <li><a href="#cxx-features">C++ Features</a></li>
   <li><a href="#shared-library">Shared Library</a></li>
   <li><a href="#deps">Dependencies</a></li>
 </ol>

 <!--=========================================================================-->
 <div class="doc_section"><a name="overview">Overview</a></div>
 <!--=========================================================================-->
 <div class="doc_text">

 <p>LLVM sets certain default configure options to make sure our developers don't
 break things for constrained platforms.  These settings are not optimal for most
 desktop systems, and we hope that packagers (e.g., Redhat, Debian, MacPorts,
 etc.) will tweak them.  This document lists settings we suggest you tweak.
 </p>

 <p>LLVM's API changes with each release, so users are likely to want, for
 example, both LLVM-2.6 and LLVM-2.7 installed at the same time to support apps
 developed against each.
 </p>
 </div>

 <!--=========================================================================-->
 <div class="doc_section"><a name="compilation">Compile Flags</a></div>
 <!--=========================================================================-->
 <div class="doc_text">

 <p>LLVM runs much more quickly when it's optimized and assertions are removed.
 However, such a build is currently incompatible with users who build without
 defining NDEBUG, and the lack of assertions makes it hard to debug problems in
 user code.  We recommend allowing users to install both optimized and debug
 versions of LLVM in parallel.  The following configure flags are relevant:
 </p>

 <dl>
   <dt><tt>--disable-assertions</tt></dt><dd>Builds LLVM with <tt>NDEBUG</tt>
   defined.  Changes the LLVM ABI.  Also available by setting
   <tt>DISABLE_ASSERTIONS=0|1</tt> in <tt>make</tt>'s environment.  This defaults
   to enabled regardless of the optimization setting, but it slows things
   down.</dd>

   <dt><tt>--enable-debug-symbols</tt></dt><dd>Builds LLVM with <tt>-g</tt>.
   Also available by setting <tt>DEBUG_SYMBOLS=0|1</tt> in <tt>make</tt>'s
   environment.  This defaults to disabled when optimizing, so you should turn it
   back on to let users debug their programs.</dd>

   <dt><tt>--enable-optimized</tt></dt><dd>(For svn checkouts) Builds LLVM with
   <tt>-O2</tt> and, by default, turns off debug symbols.  Also available by
   setting <tt>ENABLE_OPTIMIZED=0|1</tt> in <tt>make</tt>'s environment.  This
   defaults to enabled when not in a checkout.</dd>
 </dl>
 </div>

 <!--=========================================================================-->
 <div class="doc_section"><a name="cxx-features">C++ Features</a></div>
 <!--=========================================================================-->
 <div class="doc_text">

 <dl>
   <dt>RTTI</dt><dd>LLVM disables RTTI by default.  Add <tt>REQUIRES_RTTI=1</tt>
   to your environment while running <tt>make</tt> to re-enable it.  This will
   allow users to build with RTTI enabled and still inherit from LLVM
   classes.</dd>
 </dl>
 </div>

 <!--=========================================================================-->
 <div class="doc_section"><a name="shared-library">Shared Library</a></div>
 <!--=========================================================================-->
 <div class="doc_text">

 <p>Configure with <tt>--enable-shared</tt> to build
 <tt>libLLVM-<var>major</var>.<var>minor</var>.(so|dylib)</tt> and link the tools
 against it.  This saves lots of binary size at the cost of some startup time.
 </p>
 </div>

 <!--=========================================================================-->
 <div class="doc_section"><a name="deps">Dependencies</a></div>
 <!--=========================================================================-->
 <div class="doc_text">

 <dl>
 <dt><tt>--enable-libffi</tt></dt><dd>Depend on <a
 href="http://sources.redhat.com/libffi/">libffi</a> to allow the LLVM
 interpreter to call external functions.</dd>
 <dt><tt>--with-oprofile</tt></dt><dd>Depend on <a
 href="http://oprofile.sourceforge.net/doc/devel/index.html">libopagent</a>
 (>=version 0.9.4) to let the LLVM JIT tell oprofile about function addresses and
 line numbers.</dd>
 </dl>
 </div>

 <!-- *********************************************************************** -->
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   Last modified: $Date$
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 </body>
 </html>
	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
	"http://www.w3.org/TR/html4/strict.dtd">
	<html>
	<head>
	<title>Advice on Packaging LLVM</title>
	<link rel="stylesheet" href="llvm.css" type="text/css">
	</head>
	<body>

	<div class="doc_title">Advice on Packaging LLVM</div>
	<ol>
	<li><a href="#overview">Overview</a></li>
	<li><a href="#compilation">Compile Flags</a></li>
	<li><a href="#cxx-features">C++ Features</a></li>
	<li><a href="#shared-library">Shared Library</a></li>
	<li><a href="#deps">Dependencies</a></li>
	</ol>

	<!--=========================================================================-->
	<div class="doc_section"><a name="overview">Overview</a></div>
	<!--=========================================================================-->
	<div class="doc_text">

	<p>LLVM sets certain default configure options to make sure our developers don't
	break things for constrained platforms. These settings are not optimal for most
	desktop systems, and we hope that packagers (e.g., Redhat, Debian, MacPorts,
	etc.) will tweak them. This document lists settings we suggest you tweak.
	</p>

	<p>LLVM's API changes with each release, so users are likely to want, for
	example, both LLVM-2.6 and LLVM-2.7 installed at the same time to support apps
	developed against each.
	</p>
	</div>

	<!--=========================================================================-->
	<div class="doc_section"><a name="compilation">Compile Flags</a></div>
	<!--=========================================================================-->
	<div class="doc_text">

	<p>LLVM runs much more quickly when it's optimized and assertions are removed.
	However, such a build is currently incompatible with users who build without
	defining NDEBUG, and the lack of assertions makes it hard to debug problems in
	user code. We recommend allowing users to install both optimized and debug
	versions of LLVM in parallel. The following configure flags are relevant:
	</p>

	<dl>
	<dt><tt>--disable-assertions</tt></dt><dd>Builds LLVM with <tt>NDEBUG</tt>
	defined. Changes the LLVM ABI. Also available by setting
	<tt>DISABLE_ASSERTIONS=0\|1</tt> in <tt>make</tt>'s environment. This defaults
	to enabled regardless of the optimization setting, but it slows things
	down.</dd>

	<dt><tt>--enable-debug-symbols</tt></dt><dd>Builds LLVM with <tt>-g</tt>.
	Also available by setting <tt>DEBUG_SYMBOLS=0\|1</tt> in <tt>make</tt>'s
	environment. This defaults to disabled when optimizing, so you should turn it
	back on to let users debug their programs.</dd>

	<dt><tt>--enable-optimized</tt></dt><dd>(For svn checkouts) Builds LLVM with
	<tt>-O2</tt> and, by default, turns off debug symbols. Also available by
	setting <tt>ENABLE_OPTIMIZED=0\|1</tt> in <tt>make</tt>'s environment. This
	defaults to enabled when not in a checkout.</dd>
	</dl>
	</div>

	<!--=========================================================================-->
	<div class="doc_section"><a name="cxx-features">C++ Features</a></div>
	<!--=========================================================================-->
	<div class="doc_text">

	<dl>
	<dt>RTTI</dt><dd>LLVM disables RTTI by default. Add <tt>REQUIRES_RTTI=1</tt>
	to your environment while running <tt>make</tt> to re-enable it. This will
	allow users to build with RTTI enabled and still inherit from LLVM
	classes.</dd>
	</dl>
	</div>

	<!--=========================================================================-->
	<div class="doc_section"><a name="shared-library">Shared Library</a></div>
	<!--=========================================================================-->
	<div class="doc_text">

	<p>Configure with <tt>--enable-shared</tt> to build
	<tt>libLLVM-<var>major</var>.<var>minor</var>.(so\|dylib)</tt> and link the tools
	against it. This saves lots of binary size at the cost of some startup time.
	</p>
	</div>

	<!--=========================================================================-->
	<div class="doc_section"><a name="deps">Dependencies</a></div>
	<!--=========================================================================-->
	<div class="doc_text">

	<dl>
	<dt><tt>--enable-libffi</tt></dt><dd>Depend on <a
	href="http://sources.redhat.com/libffi/">libffi</a> to allow the LLVM
	interpreter to call external functions.</dd>
	<dt><tt>--with-oprofile</tt></dt><dd>Depend on <a
	href="http://oprofile.sourceforge.net/doc/devel/index.html">libopagent</a>
	(>=version 0.9.4) to let the LLVM JIT tell oprofile about function addresses and
	line numbers.</dd>
	</dl>
	</div>

	<!-- *********************************************************************** -->
	<hr>
	<address>
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	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
	Last modified: $Date$
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