PTH -> PCH in the user manual

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72815 91177308-0d34-0410-b5e6-96231b3b80d8

docs/UsersManual.html

@@ -431,50 +431,43 @@ headers vary between compilers, precompiled headers have been shown to be a
 highly effective at speeding up program compilation on systems with very large
 system headers (e.g., Mac OS/X).</p>
 
-<p>Clang supports an implementation of precompiled headers known as
-<em>pre-tokenized headers</em> (PTH). Clang's pre-tokenized headers support most
-of same interfaces as GCC's pre-compiled headers (as well as others) but are
-completely different in their implementation.  If you are interested in how
-PTH is implemented, please see the <a href="PTHInternals.html">PTH Internals
- document</a>.</p>
+<h4>Generating a PCH File</h4>
 
-<h4>Generating a PTH File</h4>
-
-<p>To generate a PTH file using Clang, one invokes Clang with
+<p>To generate a PCH file using Clang, one invokes Clang with
 the <b><tt>-x <i>&lt;language&gt;</i>-header</tt></b> option. This mirrors the
 interface in GCC for generating PCH files:</p>
 
 <pre>
   $ gcc -x c-header test.h -o test.h.gch
-  $ clang -x c-header test.h -o test.h.pth
+  $ clang -x c-header test.h -o test.h.pch
 </pre>
 
-<h4>Using a PTH File</h4>
+<h4>Using a PCH File</h4>
 
-<p>A PTH file can then be used as a prefix header when a
+<p>A PCH file can then be used as a prefix header when a
 <b><tt>-include</tt></b> option is passed to <tt>clang</tt>:</p>
 
 <pre>
   $ clang -include test.h test.c -o test
 </pre>
 
-<p>The <tt>clang</tt> driver will first check if a PTH file for <tt>test.h</tt>
+<p>The <tt>clang</tt> driver will first check if a PCH file for <tt>test.h</tt>
 is available; if so, the contents of <tt>test.h</tt> (and the files it includes)
-will be processed from the PTH file. Otherwise, Clang falls back to
+will be processed from the PCH file. Otherwise, Clang falls back to
 directly processing the content of <tt>test.h</tt>. This mirrors the behavior of
 GCC.</p>
 
-<p><b>NOTE:</b> Clang does <em>not</em> automatically use PTH files
+<p><b>NOTE:</b> Clang does <em>not</em> automatically use PCH files
 for headers that are directly included within a source file. For example:</p>
 
 <pre>
-  $ clang -x c-header test.h -o test.h.pth
+  $ clang -x c-header test.h -o test.h.cth
   $ cat test.c
   #include "test.h"
   $ clang test.c -o test
 </pre>
 
-<p>In this example, <tt>clang</tt> will not automatically use the PTH file for
+<p>In this example, <tt>clang</tt> will not automatically use the PCH file for
 <tt>test.h</tt> since <tt>test.h</tt> was included directly in the source file
 and not specified on the command line using <tt>-include</tt>.</p>