-<!-- $PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.114 2006/05/30 21:21:29 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.115 2006/05/31 20:58:09 tgl Exp $ -->
<sect1 id="xfunc">
<title>User-Defined Functions</title>
</para>
</listitem>
+ <listitem>
+ <para>
+ To ensure your module is not loaded into an incompatible server,
+ it must include a <quote>magic block</>. This allows
+ the server to detect obvious incompatibilities, such as a module
+ compiled for a different major version of
+ <productname>PostgreSQL</productname>. A magic block is required
+ as of <productname>PostgreSQL</productname> 8.2. To include a magic
+ block, write this in one (and only one) of your module source files,
+ after having included the header <filename>fmgr.h</>:
+ </para>
+
+<programlisting>
+#ifdef PG_MODULE_MAGIC
+PG_MODULE_MAGIC;
+#endif
+</programlisting>
+
+ <para>
+ The <literal>#ifdef</> test can be omitted if your code doesn't
+ need to compile against pre-8.2 <productname>PostgreSQL</productname>
+ releases.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Compiling and linking your code so that it can be dynamically
+ loaded into <productname>PostgreSQL</productname> always
+ requires special flags. See <xref linkend="dfunc"> for a
+ detailed explanation of how to do it for your particular
+ operating system.
+ </para>
+ </listitem>
+
<listitem>
<para>
When allocating memory, use the
error messages to this effect.
</para>
</listitem>
-
- <listitem>
- <para>
- To ensure your module is not loaded into an incompatible server, it
- is recommended to include a <quote>magic block</>. This allows
- the server to detect obvious incompatibilities, such as a module
- compiled for a different major version of
- <productname>PostgreSQL</productname>. It is likely that magic
- blocks will be required in future releases. To include a magic
- block, write this in one (and only one) of your module source files,
- after having included the header <filename>fmgr.h</>:
- </para>
-
-<programlisting>
-#ifdef PG_MODULE_MAGIC
-PG_MODULE_MAGIC;
-#endif
-</programlisting>
-
- <para>
- The <literal>#ifdef</> test can be omitted if your code doesn't
- need to compile against pre-8.2 <productname>PostgreSQL</productname>
- releases.
- </para>
- </listitem>
-
- <listitem>
- <para>
- Compiling and linking your code so that it can be dynamically
- loaded into <productname>PostgreSQL</productname> always
- requires special flags. See <xref linkend="dfunc"> for a
- detailed explanation of how to do it for your particular
- operating system.
- </para>
- </listitem>
</itemizedlist>
</para>
</sect2>
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/fmgr/dfmgr.c,v 1.84 2006/05/30 21:21:30 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/fmgr/dfmgr.c,v 1.85 2006/05/31 20:58:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
}
else
{
- /*
- * Currently we do not reject modules for not having a
- * magic block, it would break every external module in
- * existence. At some point though, this will become an ERROR.
- */
- ereport(LOG,
- (errmsg("library \"%s\" does not have a magic block",
- fullname)));
+ /* try to unlink library */
+ pg_dlclose(file_scanner->handle);
+ free((char *) file_scanner);
+ /* complain */
+ ereport(ERROR,
+ (errmsg("incompatible library \"%s\": missing magic block",
+ fullname),
+ errhint("Extension libraries are now required to use the PG_MODULE_MAGIC macro.")));
}
/* OK to link it into list */
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.44 2006/05/30 21:21:30 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.45 2006/05/31 20:58:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/*-------------------------------------------------------------------------
* Support for verifying backend compatibility of loaded modules
*
- * If a loaded module includes the macro call
+ * We require dynamically-loaded modules to include the macro call
* PG_MODULE_MAGIC;
- * (put this in only one source file), then we can check for obvious
- * incompatibility, such as being compiled for a different major PostgreSQL
- * version.
+ * so that we can check for obvious incompatibility, such as being compiled
+ * for a different major PostgreSQL version.
*
* To compile with versions of PostgreSQL that do not support this,
- * you may put an #ifdef/#endif test around it.
+ * you may put an #ifdef/#endif test around it. Note that in a multiple-
+ * source-file module, the macro call should only appear once.
*
* The specific items included in the magic block are intended to be ones that
* are custom-configurable and especially likely to break dynamically loaded
-/* $PostgreSQL: pgsql/src/tutorial/funcs.c,v 1.14 2006/03/11 04:38:42 momjian Exp $ */
+/* $PostgreSQL: pgsql/src/tutorial/funcs.c,v 1.15 2006/05/31 20:58:09 tgl Exp $ */
/******************************************************************************
These are user-defined functions that can be bound to a Postgres backend
#include "executor/executor.h" /* for GetAttributeByName() */
#include "utils/geo_decls.h" /* for point type */
+PG_MODULE_MAGIC;
+
/* These prototypes just prevent possible warnings from gcc. */