X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=docs%2Fusers_guide%2Fffi-chap.xml;h=82f3899a76c0de7e18e0f6ce1f4aacca811653bf;hb=41c6c5d091021a859a7508b47e9fa8a19230b033;hp=78c23f8f9e0b1d420ba2f250804a5caefb091e40;hpb=284e6b500dd92bb132845c39ec1a9d8ef78c009a;p=ghc-hetmet.git

diff --git a/docs/users_guide/ffi-chap.xml b/docs/users_guide/ffi-chap.xml
index 78c23f8..82f3899 100644
--- a/docs/users_guide/ffi-chap.xml
+++ b/docs/users_guide/ffi-chap.xml
@@ -25,7 +25,7 @@ the <option>-fglasgow-exts</option><indexterm><primary><option>-fglasgow-exts</o
 
     <listitem>
       <para>GHC implements a number of GHC-specific extensions to the FFI
-      Addendum.  These extensions are described in <xref linkend="sec-ffi-ghcexts" />, but please note that programs using
+      Addendum.  These extensions are described in <xref linkend="ffi-ghcexts" />, but please note that programs using
       these features are not portable.  Hence, these features should be
       avoided where possible.</para>
     </listitem>
@@ -35,7 +35,7 @@ the <option>-fglasgow-exts</option><indexterm><primary><option>-fglasgow-exts</o
   documentation; see for example the <literal>Foreign</literal>
   module.</para>
 
-  <sect1 id="sec-ffi-ghcexts">
+  <sect1 id="ffi-ghcexts">
     <title>GHC extensions to the FFI Addendum</title>
 
     <para>The FFI features that are described in this section are specific to
@@ -54,7 +54,7 @@ the <option>-fglasgow-exts</option><indexterm><primary><option>-fglasgow-exts</o
       and <literal>ByteArray#</literal>.</para>
     </sect2>
 
-    <sect2>
+    <sect2 id="ffi-newtype-io">
       <title>Newtype wrapping of the IO monad</title>
       <para>The FFI spec requires the IO monad to appear in various  places,
       but it can sometimes be convenient to wrap the IO monad in a
@@ -81,7 +81,7 @@ OK:
 
   </sect1>
 
-  <sect1 id="sec-ffi-ghc">
+  <sect1 id="ffi-ghc">
     <title>Using the FFI with GHC</title>
 
     <para>The following sections also give some hints and tips on the
@@ -214,7 +214,41 @@ int main(int argc, char *argv[])
 	<replaceable>M</replaceable> is
 	<literal>__stginit_<replaceable>M</replaceable></literal>, and
 	it may be declared as an external function symbol as in the
-	code above.</para>
+	code above.  Note that the symbol name should be transformed
+	according to the Z-encoding:</para>
+
+      <informaltable>
+	<tgroup cols="2" align="left" colsep="1" rowsep="1">
+	  <thead>
+	    <row>
+	      <entry>Character</entry>
+	      <entry>Replacement</entry>
+	    </row>
+	  </thead>
+	  <tbody>
+	    <row>
+	      <entry><literal>.</literal></entry>
+	      <entry><literal>zd</literal></entry>
+	    </row>
+	    <row>
+	      <entry><literal>_</literal></entry>
+	      <entry><literal>zu</literal></entry>
+	    </row>
+	    <row>
+	      <entry><literal>`</literal></entry>
+	      <entry><literal>zq</literal></entry>
+	    </row>
+	    <row>
+	      <entry><literal>Z</literal></entry>
+	      <entry><literal>ZZ</literal></entry>
+	    </row>
+	    <row>
+	      <entry><literal>z</literal></entry>
+	      <entry><literal>zz</literal></entry>
+	    </row>
+          </tbody>
+        </tgroup>
+      </informaltable>
 
 	<para>After we've finished invoking our Haskell functions, we
 	can call <literal>hs_exit()</literal>, which