Add proallargtypes and proargmodes columns to pg_proc, as per my earlier

proposal for OUT parameter support.  The columns don't actually *do*
anything yet, they are just left NULLs.  But I thought I'd commit this
part separately as a fairly pure example of the tasks needed when adding
a column to pg_proc or one of the other core system tables.

doc/src/sgml/bki.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/bki.sgml,v 1.13 2005/01/05 23:42:03 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/bki.sgml,v 1.14 2005/03/29 19:44:22 tgl Exp $
  -->
 
 <chapter id="bki">
@@ -97,6 +97,7 @@ $PostgreSQL: pgsql/doc/src/sgml/bki.sgml,v 1.13 2005/01/05 23:42:03 tgl Exp $
       <type>oid</type>, <type>tid</type>, <type>xid</type>,
       <type>cid</type>, <type>int2vector</type>, <type>oidvector</type>,
       <type>_int4</type> (array), <type>_text</type> (array),
+      <type>_oid</type> (array), <type>_char</type> (array),
       <type>_aclitem</type> (array).  Although it is possible to create
       tables containing columns of other types, this cannot be done until
       after <structname>pg_type</> has been created and filled with

doc/src/sgml/catalogs.sgml

@@ -1,6 +1,6 @@
 <!--
  Documentation of the system catalogs, directed toward PostgreSQL developers
- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.98 2005/03/29 00:16:49 tgl Exp $
+ $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.99 2005/03/29 19:44:22 tgl Exp $
  -->
 
 <chapter id="catalogs">
@@ -2855,7 +2855,39 @@
       <entry><structfield>proargtypes</structfield></entry>
       <entry><type>oidvector</type></entry>
       <entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
-      <entry>An array with the data types of the function arguments</entry>
+      <entry>
+       An array with the data types of the function arguments.  This includes
+       only input arguments (including INOUT arguments), and thus represents
+       the call signature of the function.
+      </entry>
+     </row>
+
+     <row>
+      <entry><structfield>proallargtypes</structfield></entry>
+      <entry><type>oid[]</type></entry>
+      <entry><literal><link linkend="catalog-pg-type"><structname>pg_type</structname></link>.oid</literal></entry>
+      <entry>
+       An array with the data types of the function arguments.  This includes
+       all arguments (including OUT and INOUT arguments); however, if all the
+       arguments are IN arguments, this field will be null.
+       Note that subscripting is 1-based, whereas for historical reasons
+       <structfield>proargtypes</> is subscripted from 0.
+      </entry>
+     </row>
+
+     <row>
+      <entry><structfield>proargmodes</structfield></entry>
+      <entry><type>"char"[]</type></entry>
+      <entry></entry>
+      <entry>
+        An array with the modes of the function arguments, encoded as
+        <literal>i</literal> for IN arguments,
+        <literal>o</literal> for OUT arguments,
+        <literal>b</literal> for INOUT arguments.
+        If all the arguments are IN arguments, this field will be null.
+        Note that subscripts correspond to positions of
+        <structfield>proallargtypes</> not <structfield>proargtypes</>.
+      </entry>
      </row>
 
      <row>
@@ -2865,7 +2897,9 @@
       <entry>
         An array with the names of the function arguments.
         Arguments without a name are set to empty strings in the array.
-        If none of the arguments have a name, this field may be null.
+        If none of the arguments have a name, this field will be null.
+        Note that subscripts correspond to positions of
+        <structfield>proallargtypes</> not <structfield>proargtypes</>.
       </entry>
      </row>