Make PG_MODULE_MAGIC required in shared libraries that are loaded into

tglsfdc · tglsfdc · commit 8f165ee13b11 · 2006-05-31T20:58:09.000Z
the server.  Per discussion, there seems no point in a waiting period
before making this required.
diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml
@@ -1,4 +1,4 @@
-<!-- $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>
@@ -1910,6 +1910,41 @@ concat_text(PG_FUNCTION_ARGS)
        </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
@@ -1960,41 +1995,6 @@ concat_text(PG_FUNCTION_ARGS)
         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>
diff --git a/src/backend/utils/fmgr/dfmgr.c b/src/backend/utils/fmgr/dfmgr.c
@@ -8,7 +8,7 @@
  *
  *
  * 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 $
  *
  *-------------------------------------------------------------------------
  */
@@ -188,14 +188,14 @@ load_external_function(char *filename, char *funcname,
 		}
 		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 */
diff --git a/src/include/fmgr.h b/src/include/fmgr.h
@@ -11,7 +11,7 @@
  * 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 $
  *
  *-------------------------------------------------------------------------
  */
@@ -314,14 +314,14 @@ extern int no_such_variable
 /*-------------------------------------------------------------------------
  *		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
diff --git a/src/tutorial/funcs.c b/src/tutorial/funcs.c
@@ -1,4 +1,4 @@
-/* $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
@@ -16,6 +16,8 @@
 #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. */
 

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $PostgreSQL: pgsql/src/backend/utils/fmgr/dfmgr.c,v 1.84 2006/05/30 21:21:30 tgl Exp $`
	`11`	`+ * $PostgreSQL: pgsql/src/backend/utils/fmgr/dfmgr.c,v 1.85 2006/05/31 20:58:09 tgl Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -188,14 +188,14 @@ load_external_function(char filename, char funcname,`
`188`	`188`	`}`
`189`	`189`	`else`
`190`	`190`	`{`
`191`		`- /*`
`192`		`- * Currently we do not reject modules for not having a`
`193`		`- * magic block, it would break every external module in`
`194`		`- * existence. At some point though, this will become an ERROR.`
`195`		`- */`
`196`		`- ereport(LOG,`
`197`		`- (errmsg("library \"%s\" does not have a magic block",`
`198`		`- fullname)));`
	`191`	`+ /* try to unlink library */`
	`192`	`+ pg_dlclose(file_scanner->handle);`
	`193`	`+ free((char *) file_scanner);`
	`194`	`+ /* complain */`
	`195`	`+ ereport(ERROR,`
	`196`	`+ (errmsg("incompatible library \"%s\": missing magic block",`
	`197`	`+ fullname),`
	`198`	`+ errhint("Extension libraries are now required to use the PG_MODULE_MAGIC macro.")));`
`199`	`199`	`}`
`200`	`200`
`201`	`201`	`/* OK to link it into list */`
Original file line number	Diff line number	Diff line change
`@@ -11,7 +11,7 @@`
`11`	`11`	`* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group`
`12`	`12`	`* Portions Copyright (c) 1994, Regents of the University of California`
`13`	`13`	`*`
`14`		`- * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.44 2006/05/30 21:21:30 tgl Exp $`
	`14`	`+ * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.45 2006/05/31 20:58:09 tgl Exp $`
`15`	`15`	`*`
`16`	`16`	`*-------------------------------------------------------------------------`
`17`	`17`	`*/`
`@@ -314,14 +314,14 @@ extern int no_such_variable`
`314`	`314`	`/*-------------------------------------------------------------------------`
`315`	`315`	`* Support for verifying backend compatibility of loaded modules`
`316`	`316`	`*`
`317`		`- * If a loaded module includes the macro call`
	`317`	`+ * We require dynamically-loaded modules to include the macro call`
`318`	`318`	`* PG_MODULE_MAGIC;`
`319`		`- * (put this in only one source file), then we can check for obvious`
`320`		`- * incompatibility, such as being compiled for a different major PostgreSQL`
`321`		`- * version.`
	`319`	`+ * so that we can check for obvious incompatibility, such as being compiled`
	`320`	`+ * for a different major PostgreSQL version.`
`322`	`321`	`*`
`323`	`322`	`* To compile with versions of PostgreSQL that do not support this,`
`324`		`- * you may put an #ifdef/#endif test around it.`
	`323`	`+ * you may put an #ifdef/#endif test around it. Note that in a multiple-`
	`324`	`+ * source-file module, the macro call should only appear once.`
`325`	`325`	`*`
`326`	`326`	`* The specific items included in the magic block are intended to be ones that`
`327`	`327`	`* are custom-configurable and especially likely to break dynamically loaded`