From 67bda4331dc4f548820ed2f3138aa7f64fd4c77d Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Thu, 6 Jul 2023 16:25:47 +0100
Subject: [PATCH] libstdc++: Document --enable-cstdio=stdio_pure [PR104299]

libstdc++-v3/ChangeLog:

	PR libstdc++/104299
	* doc/xml/manual/configure.xml: Describe stdio_pure argument to
	--enable-cstdio.
	* doc/html/manual/configure.html: Regenerate.

(cherry picked from commit b90a70984a9beee39b41f842b56926f9db2069ca)
---
 libstdc++-v3/doc/html/manual/configure.html | 11 ++++++++---
 libstdc++-v3/doc/xml/manual/configure.xml   | 11 ++++++++---
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/libstdc++-v3/doc/html/manual/configure.html b/libstdc++-v3/doc/html/manual/configure.html
index 31c4da8a5e3a..5981c6c548b0 100644
--- a/libstdc++-v3/doc/html/manual/configure.html
+++ b/libstdc++-v3/doc/html/manual/configure.html
@@ -38,9 +38,14 @@
      </p><pre class="programlisting">
    --with-gxx-include-dir=/foo/H-x86-gcc-3-c-gxx-inc/include/4.4-20090404</pre></dd><dt><span class="term"><code class="code">--enable-cstdio</code></span></dt><dd><p>This is an abbreviated form of <code class="code">'--enable-cstdio=stdio'</code>
 	(described next).
-     </p></dd><dt><span class="term"><code class="code">--enable-cstdio=OPTION</code></span></dt><dd><p>Select a target-specific I/O package. At the moment, the only
-	choice is to use 'stdio', a generic "C" abstraction.
-	The default is 'stdio'. This option can change the library ABI.
+     </p></dd><dt><span class="term"><code class="code">--enable-cstdio=OPTION</code></span></dt><dd><p>Select a target-specific I/O package. The choices are 'stdio'
+       which is a generic abstraction using POSIX file I/O APIs
+       (<code class="function">read</code>, <code class="function">write</code>,
+       <code class="function">lseek</code>, etc.), and 'stdio_pure' which is similar
+       but only uses standard C file I/O APIs (<code class="function">fread</code>,
+       <code class="function">fwrite</code>, <code class="function">fseek</code>, etc.).
+       The 'stdio_posix' choice is a synonym for 'stdio'.
+       The default is 'stdio'. This option can change the library ABI.
      </p></dd><dt><span class="term"><code class="code">--enable-clocale</code></span></dt><dd><p>This is an abbreviated form of <code class="code">'--enable-clocale=generic'</code>
 	(described next).
      </p></dd><dt><span class="term"><code class="code">--enable-clocale=OPTION</code></span></dt><dd><p>Select a target-specific underlying locale package.  The
diff --git a/libstdc++-v3/doc/xml/manual/configure.xml b/libstdc++-v3/doc/xml/manual/configure.xml
index 8c26acc95a79..f01fdb9b0d4f 100644
--- a/libstdc++-v3/doc/xml/manual/configure.xml
+++ b/libstdc++-v3/doc/xml/manual/configure.xml
@@ -74,9 +74,14 @@
  </listitem></varlistentry>
 
  <varlistentry><term><code>--enable-cstdio=OPTION</code></term>
- <listitem><para>Select a target-specific I/O package. At the moment, the only
-	choice is to use 'stdio', a generic "C" abstraction.
-	The default is 'stdio'. This option can change the library ABI.
+ <listitem><para>Select a target-specific I/O package. The choices are 'stdio'
+       which is a generic abstraction using POSIX file I/O APIs
+       (<function>read</function>, <function>write</function>,
+       <function>lseek</function>, etc.), and 'stdio_pure' which is similar
+       but only uses standard C file I/O APIs (<function>fread</function>,
+       <function>fwrite</function>, <function>fseek</function>, etc.).
+       The 'stdio_posix' choice is a synonym for 'stdio'.
+       The default is 'stdio'. This option can change the library ABI.
      </para>
  </listitem></varlistentry>
 
-- 
2.47.3