--- a/doc/building.html Fri Dec 14 17:12:14 2018 -0800
+++ b/doc/building.html Mon Dec 17 09:35:15 2018 -0800
@@ -145,7 +145,7 @@
<li><p>Do not check out the source code in a path which contains spaces. Chances are the build will not work. This is most likely to be an issue on Windows systems.</p></li>
<li><p>Do not check out the source code in a path which has a very long name or is nested many levels deep. Chances are you will hit an OS limitation during the build.</p></li>
<li><p>Put the source code on a local disk, not a network share. If possible, use an SSD. The build process is very disk intensive, and having slow disk access will significantly increase build times. If you need to use a network share for the source code, see below for suggestions on how to keep the build artifacts on a local disk.</p></li>
-<li><p>On Windows, extra care must be taken to make sure the <a href="#cygwin">Cygwin</a> environment is consistent. It is recommended that you follow this procedure:</p>
+<li><p>On Windows, if using <a href="#cygwin">Cygwin</a>, extra care must be taken to make sure the environment is consistent. It is recommended that you follow this procedure:</p>
<ul>
<li><p>Create the directory that is going to contain the top directory of the JDK clone by using the <code>mkdir</code> command in the Cygwin bash shell. That is, do <em>not</em> create it using Windows Explorer. This will ensure that it will have proper Cygwin attributes, and that it's children will inherit those attributes.</p></li>
<li><p>Do not put the JDK clone in a path under your Cygwin home directory. This is especially important if your user name contains spaces and/or mixed upper and lower case letters.</p></li>
@@ -201,8 +201,11 @@
<h3 id="windows">Windows</h3>
<p>Windows XP is not a supported platform, but all newer Windows should be able to build the JDK.</p>
<p>On Windows, it is important that you pay attention to the instructions in the <a href="#special-considerations">Special Considerations</a>.</p>
-<p>Windows is the only non-POSIX OS supported by the JDK, and as such, requires some extra care. A POSIX support layer is required to build on Windows. Currently, the only supported such layer is Cygwin. (Msys is no longer supported due to a too old bash; msys2 and the new Windows Subsystem for Linux (WSL) would likely be possible to support in a future version but that would require effort to implement.)</p>
+<p>Windows is the only non-POSIX OS supported by the JDK, and as such, requires some extra care. A POSIX support layer is required to build on Windows. Currently, the only supported such layers are Windows Subsystem for Linux (WSL) and Cygwin. (Msys is no longer supported due to a too old bash; msys2 would likely be possible to support in a future version but that would require effort to implement.)</p>
<p>Internally in the build system, all paths are represented as Unix-style paths, e.g. <code>/cygdrive/c/hg/jdk9/Makefile</code> rather than <code>C:\hg\jdk9\Makefile</code>. This rule also applies to input to the build system, e.g. in arguments to <code>configure</code>. So, use <code>--with-msvcr-dll=/cygdrive/c/msvcr100.dll</code> rather than <code>--with-msvcr-dll=c:\msvcr100.dll</code>. For details on this conversion, see the section on <a href="#fixpath">Fixpath</a>.</p>
+<h4 id="windows-subsystem-for-linux-wsl">Windows Subsystem for Linux (WSL)</h4>
+<p>Only Windows 10 1803 or newer is supported due to a dependency on the wslpath utility and support for environment variable sharing through WSLENV.</p>
+<p>You may build both Windows and Linux binaries from WSL. To build Windows binaries, you must use a Windows boot JDK (located in a Windows-accessible directory). To build Linux binaries, you must use a Linux boot JDK. The default behavior is to build for Windows. To build for Linux, pass <code>--build=x86_64-unknown-linux-gnu</code> and <code>--host=x86_64-unknown-linux-gnu</code> to <code>configure</code>.</p>
<h4 id="cygwin">Cygwin</h4>
<p>A functioning <a href="http://www.cygwin.com/">Cygwin</a> environment is thus required for building the JDK on Windows. If you have a 64-bit OS, we strongly recommend using the 64-bit version of Cygwin.</p>
<p><strong>Note:</strong> Cygwin has a model of continuously updating all packages without any easy way to install or revert to a specific version of a package. This means that whenever you add or update a package in Cygwin, you might (inadvertently) update tools that are used by the JDK build process, and that can cause unexpected build problems.</p>