Clean up installation directory choices for extensions.

Arrange for the control files to be in $SHAREDIR/extension not
$SHAREDIR/contrib, since we're generally trying to deprecate the term
"contrib" and this is a once-in-many-moons opportunity to get rid of it in
install paths.  Fix PGXS to install the $EXTENSION file into that directory
no matter what MODULEDIR is set to; a nondefault MODULEDIR should only
affect the script and secondary extension files.  Fix the control file
directory parameter to be interpreted relative to $SHAREDIR, to avoid a
surprising disconnect between how you specify that and what you set
MODULEDIR to.

Per discussion with David Wheeler.

2 files changed, 17 insertions, 12 deletions

diff --git a/doc/src/sgml/extend.sgml b/doc/src/sgml/extend.sgml
index 93bcba9a10c..90248e59e78 100644
--- a/doc/src/sgml/extend.sgml
+++ b/doc/src/sgml/extend.sgml
@@ -365,13 +365,13 @@
      The <xref linkend="sql-createextension"> command relies on a control
      file for each extension, which must be named the same as the extension
      with a suffix of <literal>.control</>, and must be placed in the
-     installation's <literal>SHAREDIR/contrib</literal> directory.  There
+     installation's <literal>SHAREDIR/extension</literal> directory.  There
      must also be at least one <acronym>SQL</> script file, which follows the
      naming pattern
      <literal><replaceable>extension</>-<replaceable>version</>.sql</literal>
      (for example, <literal>foo-1.0.sql</> for version <literal>1.0</> of
      extension <literal>foo</>).  By default, the script file(s) are also
-     placed in the <literal>SHAREDIR/contrib</literal> directory; but the
+     placed in the <literal>SHAREDIR/extension</literal> directory; but the
      control file can specify a different directory for the script file(s).
     </para>
 
@@ -395,7 +395,9 @@
        <para>
         The directory containing the extension's <acronym>SQL</> script
         file(s).  Unless an absolute path is given, the name is relative to
-        the <literal>SHAREDIR/contrib</literal> directory.
+        the installation's <literal>SHAREDIR</literal> directory.  The
+        default behavior is equivalent to specifying
+        <literal>directory = 'extension'</>.
        </para>
       </listitem>
      </varlistentry>
@@ -905,23 +907,26 @@ include $(PGXS)
 
     <variablelist>
      <varlistentry>
-      <term><varname>MODULEDIR</varname></term>
+      <term><varname>EXTENSION</varname></term>
       <listitem>
        <para>
-        subdirectory into which EXTENSION, DATA and DOCS files should be
-        installed (if not set, default is <literal>contrib</literal>)
+        extension name(s); for each name you must provide an
+        <literal><replaceable>extension</replaceable>.control</literal> file,
+        which will be installed into
+        <literal><replaceable>prefix</replaceable>/share/extension</literal>
        </para>
       </listitem>
      </varlistentry>
 
      <varlistentry>
-      <term><varname>EXTENSION</varname></term>
+      <term><varname>MODULEDIR</varname></term>
       <listitem>
        <para>
-        extension name(s); for each name you must provide an
-        <literal><replaceable>extension</replaceable>.control</literal> file,
-        which will be installed into
-        <literal><replaceable>prefix</replaceable>/share/$MODULEDIR</literal>
+        subdirectory of <literal><replaceable>prefix</>/share</literal>
+        into which DATA and DOCS files should be installed
+        (if not set, default is <literal>extension</literal> if
+        <varname>EXTENSION</varname> is set,
+        or <literal>contrib</literal> if not)
        </para>
       </listitem>
      </varlistentry>
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index 9e0e3c440b6..d3b5fb009b3 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -67,7 +67,7 @@ CREATE EXTENSION <replaceable class="parameter">extension_name</replaceable>
         The name of the extension to be
         installed. <productname>PostgreSQL</productname> will create the
         extension using details from the file
-        <literal>SHAREDIR/contrib/</literal><replaceable class="parameter">extension</replaceable><literal>.control</literal>.
+        <literal>SHAREDIR/extension/</literal><replaceable class="parameter">extension_name</replaceable><literal>.control</literal>.
        </para>
       </listitem>
      </varlistentry>