docs/UsersManual.html - platform/external/clang - Gitiles

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 <h1>Clang Compiler User's Manual</h1>

 <ul>
 <li><a href="#intro">Introduction</a>
   <ul>
   <li><a href="#terminology">Terminology</a></li>
   <li><a href="#basicusage">Basic Usage</a></li>
   </ul>
 </li>
 <li><a href="#commandline">Command Line Options</a></li>
 <li><a href="#general_features">Language and Target-Independent Features</a>
  <ul>
   <li><a href="#diagnostics">Controlling Errors and Warnings</a></li>
   <li><a href="#precompiledheaders">Precompiled Headers</a></li>
   </ul>
 </li>
 <li><a href="#c">C Language Features</a>
   <ul>
 <!--  <li><a href="#pragmas">Pragmas Supported</a></li> -->
   <li><a href="#c_extensions">C Extensions Supported</a></li>
   <li><a href="#c_incompatibilities">Intentional Incompatibilities with
       GCC</a></li>
   </ul>
 </li>
 <li><a href="#objc">Objective-C Language Features</a>
   <ul>
   <li><a href="#objc_incompatibilities">Intentional Incompatibilities with
       GCC</a></li>
   </ul>
 </li>
 <li><a href="#cxx">C++ Language Features</a>
   <ul>
   <li>...</li>
   </ul>
 </li>
 <li><a href="#objcxx">Objective C++ Language Features</a>
   <ul>
   <li>...</li>
   </ul>
 </li>
 <li><a href="#target_features">Target-Specific Features and Limitations</a>
   <ul>
   <li><a href="#target_arch">CPU Architectures Features and Limitations</a>
     <ul>
     <li><a href="#target_arch_x86">X86</a></li>
     <li>PPC</li>
     <li>ARM</li>
     </ul>
   </li>
   <li><a href="#target_os">Operating System Features and Limitations</a>
     <ul>
     <li><a href="#target_os_darwin">Darwin (Mac OS/X)</a></li>
     <li>Linux, etc.</li>
     </ul>

   </li>
   </ul>
 </li>
 </ul>


 <!-- ======================================================================= -->
 <h2 id="intro">Introduction</h2>
 <!-- ======================================================================= -->

 <p>The Clang Compiler is an open-source compiler for the C family of programming
 languages, aiming to be the best in class implementation of these languages.
 Clang builds on the LLVM optimizer and code generator, allowing it to provide
 high-quality optimization and code generation support for many targets.  For
 more general information, please see the <a href="http://clang.llvm.org">Clang
 Web Site</a> or the <a href="http://llvm.org">LLVM Web Site</a>.</p>

 <p>This document describes important notes about using Clang as a compiler for
 an end-user, documenting the supported features, command line options, etc.  If
 you are interested in using Clang to build a tool that processes code, please
 see <a href="InternalsManual.html">the Clang Internals Manual</a>.  If you are
 interested in the <a href="http://clang.llvm.org/StaticAnalysis.html">Clang
 Static Analyzer</a>, please see its web page.</p>

 <p>Clang is designed to support the C family of programming languages, which
 includes <a href="#c">C</a>, <a href="#objc">Objective-C</a>, <a
 href="#cxx">C++</a>, and <a href="#objcxx">Objective-C++</a> as well as many
 dialects of those.  For language-specific information, please see the
 corresponding language specific section:</p>

 <ul>
 <li><a href="#c">C Language</a>: K&amp;R C, ANSI C89, ISO C90, ISO C94
     (C89+AMD1), ISO C99 (+TC1, TC2, TC3). </li>
 <li><a href="#objc">Objective-C Language</a>: ObjC 1, ObjC 2, ObjC 2.1, plus
     variants depending on base language.</li>
 <li><a href="#cxx">C++ Language Features</a></li>
 <li><a href="#objcxx">Objective C++ Language</a></li>
 </ul>

 <p>In addition to these base languages and their dialects, Clang supports a
 broad variety of language extensions, which are documented in the corresponding
 language section.  These extensions are provided to be compatible with the GCC,
 Microsoft, and other popular compilers as well as to improve functionality
 through Clang-specific features.  The Clang driver and language features are
 intentionally designed to be as compatible with the GNU GCC compiler as
 reasonably possible, easing migration from GCC to Clang.  In most cases, code
 "just works".</p>

 <p>In addition to language specific features, Clang has a variety of features
 that depend on what CPU architecture or operating system is being compiled for.
 Please see the <a href="target_features">Target-Specific Features and
 Limitations</a> section for more details.</p>

 <p>The rest of the introduction introduces some basic <a
 href="#terminology">compiler terminology</a> that is used throughout this manual
 and contains a basic <a href="#basicusage">introduction to using Clang</a>
 as a command line compiler.</p>

 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
 <h3 id="terminology">Terminology</h3>
 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

 <p>Front end, parser, backend, preprocessor, undefined behavior, diagnostic,
  optimizer</p>

 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
 <h3 id="basicusage">Basic Usage</h3>
 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

 <p>Intro to how to use a C compiler for newbies.</p>
 <p>
 compile + link

 compile then link

 debug info

 enabling optimizations

 picking a language to use, defaults to C99 by default.  Autosenses based on
 extension.

 using a makefile
 </p>


 <!-- ======================================================================= -->
 <h2 id="commandline">Command Line Options</h2>
 <!-- ======================================================================= -->

 <p>
 This section is generally an index into other sections.  It does not go into
 depth on most.  However, the first part introduces the language selection and
 other high level options like -c, -g, etc.
 </p>

 <!-- ======================================================================= -->
 <h2 id="general_features">Language and Target-Independent Features</h2>
 <!-- ======================================================================= -->


 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
 <h3 id="diagnostics">Controlling Errors and Warnings</h3>
 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->


 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
 <h3 id="precompiledheaders">Precompiled Headers</h3>
 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->


 <!-- ======================================================================= -->
 <h2 id="c">C Language Features</h2>
 <!-- ======================================================================= -->


 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
 <h3 id="c_incompatibilities">Intentional Incompatibilities with GCC</h3>
 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

 <p>No VLAs in structs.</p>


 <!-- ======================================================================= -->
 <h2 id="objc">Objective-C Language Features</h2>
 <!-- ======================================================================= -->


 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
 <h3 id="objc_incompatibilities">Intentional Incompatibilities with GCC</h3>
 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

 <p>No cast of super, no lvalue casts.</p>


 <!-- ======================================================================= -->
 <h2 id="cxx">C++ Language Features</h2>
 <!-- ======================================================================= -->

 <p>At this point, Clang C++ is not generally useful.  However, Clang C++ support
 is under active development and is progressing rapidly.  Please see the <a
 href="http://clang.llvm.org/cxx_status.html">C++ Status</a> page for details or
 ask on the mailing list about how you can help.</p>

 <p>Note that the clang driver will refuse to even try to use clang to compile
 C++ code unless you pass the <tt>-ccc-clang-cxx</tt> option to the driver.  If
 you really want to play with Clang's C++ support, please pass that flag. </p>

 <!-- ======================================================================= -->
 <h2 id="objcxx">Objective C++ Language Features</h2>
 <!-- ======================================================================= -->

 <p>At this point, Clang C++ support is not generally useful (and therefore,
 neither is Objective-C++).  Please see the <a href="#cxx">C++ section</a> for
 more information.</p>

 <!-- ======================================================================= -->
 <h2 id="target_features">Target-Specific Features and Limitations</h2>
 <!-- ======================================================================= -->


 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
 <h3 id="target_arch">CPU Architectures Features and Limitations</h3>
 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

 <!-- ======================== -->
 <h4 id="target_arch_x86">X86</h4>
 <!-- ======================== -->


 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
 <h3 id="target_os">Operating System Features and Limitations</h3>
 <!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

 <!-- ======================================= -->
 <h4 id="target_os_darwin">Darwin (Mac OS/X)</h4>
 <!-- ======================================= -->

 <p>No __thread support, 64-bit ObjC support requires SL tools.</p>

 </div>
 </body>
 </html>
	<html>
	<head>
	<title>Clang Compiler User's Manual</title>
	<link type="text/css" rel="stylesheet" href="../menu.css" />
	<link type="text/css" rel="stylesheet" href="../content.css" />
	<style type="text/css">
	td {
	vertical-align: top;
	}
	</style>
	</head>
	<body>

	<!--#include virtual="../menu.html.incl"-->

	<div id="content">

	<h1>Clang Compiler User's Manual</h1>

	<ul>
	<li><a href="#intro">Introduction</a>
	<ul>
	<li><a href="#terminology">Terminology</a></li>
	<li><a href="#basicusage">Basic Usage</a></li>
	</ul>
	</li>
	<li><a href="#commandline">Command Line Options</a></li>
	<li><a href="#general_features">Language and Target-Independent Features</a>
	<ul>
	<li><a href="#diagnostics">Controlling Errors and Warnings</a></li>
	<li><a href="#precompiledheaders">Precompiled Headers</a></li>
	</ul>
	</li>
	<li><a href="#c">C Language Features</a>
	<ul>
	<!-- <li><a href="#pragmas">Pragmas Supported</a></li> -->
	<li><a href="#c_extensions">C Extensions Supported</a></li>
	<li><a href="#c_incompatibilities">Intentional Incompatibilities with
	GCC</a></li>
	</ul>
	</li>
	<li><a href="#objc">Objective-C Language Features</a>
	<ul>
	<li><a href="#objc_incompatibilities">Intentional Incompatibilities with
	GCC</a></li>
	</ul>
	</li>
	<li><a href="#cxx">C++ Language Features</a>
	<ul>
	<li>...</li>
	</ul>
	</li>
	<li><a href="#objcxx">Objective C++ Language Features</a>
	<ul>
	<li>...</li>
	</ul>
	</li>
	<li><a href="#target_features">Target-Specific Features and Limitations</a>
	<ul>
	<li><a href="#target_arch">CPU Architectures Features and Limitations</a>
	<ul>
	<li><a href="#target_arch_x86">X86</a></li>
	<li>PPC</li>
	<li>ARM</li>
	</ul>
	</li>
	<li><a href="#target_os">Operating System Features and Limitations</a>
	<ul>
	<li><a href="#target_os_darwin">Darwin (Mac OS/X)</a></li>
	<li>Linux, etc.</li>
	</ul>

	</li>
	</ul>
	</li>
	</ul>


	<!-- ======================================================================= -->
	<h2 id="intro">Introduction</h2>
	<!-- ======================================================================= -->

	<p>The Clang Compiler is an open-source compiler for the C family of programming
	languages, aiming to be the best in class implementation of these languages.
	Clang builds on the LLVM optimizer and code generator, allowing it to provide
	high-quality optimization and code generation support for many targets. For
	more general information, please see the <a href="http://clang.llvm.org">Clang
	Web Site</a> or the <a href="http://llvm.org">LLVM Web Site</a>.</p>

	<p>This document describes important notes about using Clang as a compiler for
	an end-user, documenting the supported features, command line options, etc. If
	you are interested in using Clang to build a tool that processes code, please
	see <a href="InternalsManual.html">the Clang Internals Manual</a>. If you are
	interested in the <a href="http://clang.llvm.org/StaticAnalysis.html">Clang
	Static Analyzer</a>, please see its web page.</p>

	<p>Clang is designed to support the C family of programming languages, which
	includes <a href="#c">C</a>, <a href="#objc">Objective-C</a>, <a
	href="#cxx">C++</a>, and <a href="#objcxx">Objective-C++</a> as well as many
	dialects of those. For language-specific information, please see the
	corresponding language specific section:</p>

	<ul>
	<li><a href="#c">C Language</a>: K&R C, ANSI C89, ISO C90, ISO C94
	(C89+AMD1), ISO C99 (+TC1, TC2, TC3). </li>
	<li><a href="#objc">Objective-C Language</a>: ObjC 1, ObjC 2, ObjC 2.1, plus
	variants depending on base language.</li>
	<li><a href="#cxx">C++ Language Features</a></li>
	<li><a href="#objcxx">Objective C++ Language</a></li>
	</ul>

	<p>In addition to these base languages and their dialects, Clang supports a
	broad variety of language extensions, which are documented in the corresponding
	language section. These extensions are provided to be compatible with the GCC,
	Microsoft, and other popular compilers as well as to improve functionality
	through Clang-specific features. The Clang driver and language features are
	intentionally designed to be as compatible with the GNU GCC compiler as
	reasonably possible, easing migration from GCC to Clang. In most cases, code
	"just works".</p>

	<p>In addition to language specific features, Clang has a variety of features
	that depend on what CPU architecture or operating system is being compiled for.
	Please see the <a href="target_features">Target-Specific Features and
	Limitations</a> section for more details.</p>

	<p>The rest of the introduction introduces some basic <a
	href="#terminology">compiler terminology</a> that is used throughout this manual
	and contains a basic <a href="#basicusage">introduction to using Clang</a>
	as a command line compiler.</p>

	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
	<h3 id="terminology">Terminology</h3>
	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

	<p>Front end, parser, backend, preprocessor, undefined behavior, diagnostic,
	optimizer</p>

	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
	<h3 id="basicusage">Basic Usage</h3>
	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

	<p>Intro to how to use a C compiler for newbies.</p>
	<p>
	compile + link

	compile then link

	debug info

	enabling optimizations

	picking a language to use, defaults to C99 by default. Autosenses based on
	extension.

	using a makefile
	</p>


	<!-- ======================================================================= -->
	<h2 id="commandline">Command Line Options</h2>
	<!-- ======================================================================= -->

	<p>
	This section is generally an index into other sections. It does not go into
	depth on most. However, the first part introduces the language selection and
	other high level options like -c, -g, etc.
	</p>

	<!-- ======================================================================= -->
	<h2 id="general_features">Language and Target-Independent Features</h2>
	<!-- ======================================================================= -->


	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
	<h3 id="diagnostics">Controlling Errors and Warnings</h3>
	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->


	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
	<h3 id="precompiledheaders">Precompiled Headers</h3>
	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->



	<!-- ======================================================================= -->
	<h2 id="c">C Language Features</h2>
	<!-- ======================================================================= -->


	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
	<h3 id="c_incompatibilities">Intentional Incompatibilities with GCC</h3>
	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

	<p>No VLAs in structs.</p>




	<!-- ======================================================================= -->
	<h2 id="objc">Objective-C Language Features</h2>
	<!-- ======================================================================= -->


	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
	<h3 id="objc_incompatibilities">Intentional Incompatibilities with GCC</h3>
	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

	<p>No cast of super, no lvalue casts.</p>



	<!-- ======================================================================= -->
	<h2 id="cxx">C++ Language Features</h2>
	<!-- ======================================================================= -->

	<p>At this point, Clang C++ is not generally useful. However, Clang C++ support
	is under active development and is progressing rapidly. Please see the <a
	href="http://clang.llvm.org/cxx_status.html">C++ Status</a> page for details or
	ask on the mailing list about how you can help.</p>

	<p>Note that the clang driver will refuse to even try to use clang to compile
	C++ code unless you pass the <tt>-ccc-clang-cxx</tt> option to the driver. If
	you really want to play with Clang's C++ support, please pass that flag. </p>

	<!-- ======================================================================= -->
	<h2 id="objcxx">Objective C++ Language Features</h2>
	<!-- ======================================================================= -->

	<p>At this point, Clang C++ support is not generally useful (and therefore,
	neither is Objective-C++). Please see the <a href="#cxx">C++ section</a> for
	more information.</p>

	<!-- ======================================================================= -->
	<h2 id="target_features">Target-Specific Features and Limitations</h2>
	<!-- ======================================================================= -->


	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
	<h3 id="target_arch">CPU Architectures Features and Limitations</h3>
	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

	<!-- ======================== -->
	<h4 id="target_arch_x86">X86</h4>
	<!-- ======================== -->


	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->
	<h3 id="target_os">Operating System Features and Limitations</h3>
	<!-- = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = -->

	<!-- ======================================= -->
	<h4 id="target_os_darwin">Darwin (Mac OS/X)</h4>
	<!-- ======================================= -->

	<p>No __thread support, 64-bit ObjC support requires SL tools.</p>

	</div>
	</body>
	</html>