Add a -Warn flag

[ghc-hetmet.git] / docs / users_guide / using.xml

diff --git a/docs/users_guide/using.xml b/docs/users_guide/using.xml
index 9df6eb5..2fe5959 100644 (file)
--- a/docs/users_guide/using.xml
+++ b/docs/users_guide/using.xml
@@ -73,10 +73,9 @@ module X where
       maintains internally, so you'll be desperately disappointed if
       you try to glob etc. inside <literal>OPTIONS_GHC</literal>.</para>
 
-      <para>NOTE: the contents of OPTIONS_GHC are prepended to the
-      command-line options, so you <emphasis>do</emphasis> have the
-      ability to override OPTIONS_GHC settings via the command
-      line.</para>
+      <para>NOTE: the contents of OPTIONS_GHC are appended to the
+      command-line options, so options given in the source file
+      override those given on the command-line.</para>
 
       <para>It is not recommended to move all the contents of your
       Makefiles into your source files, but in some circumstances, the
@@ -898,6 +897,16 @@ ghc -c Foo.hs</screen>
        </listitem>
       </varlistentry>
 
+      <varlistentry>
+       <term><option>-Wwarn</option>:</term>
+       <listitem>
+         <indexterm><primary><option>-Wwarn</option></primary></indexterm>
+         <para>Warnings are treated only as warnings, not as errors. This is
+           the default, but can be useful to negate a
+        <option>-Werror</option> flag.</para>
+       </listitem>
+      </varlistentry>
+
     </variablelist>
 
     <para>The full set of warning options is described below.  To turn