From 8f165ee13b11baf17b91d858c535419c33a755d6 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 31 May 2006 20:58:09 +0000 Subject: [PATCH] Make PG_MODULE_MAGIC required in shared libraries that are loaded into the server. Per discussion, there seems no point in a waiting period before making this required. --- doc/src/sgml/xfunc.sgml | 72 +++++++++++++++++----------------- src/backend/utils/fmgr/dfmgr.c | 18 ++++----- src/include/fmgr.h | 12 +++--- src/tutorial/funcs.c | 4 +- 4 files changed, 54 insertions(+), 52 deletions(-) diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index b803ea2c9ee..6321bf5b0a7 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -1,4 +1,4 @@ - + User-Defined Functions @@ -1910,6 +1910,41 @@ concat_text(PG_FUNCTION_ARGS) + + + To ensure your module is not loaded into an incompatible server, + it must include a magic block. This allows + the server to detect obvious incompatibilities, such as a module + compiled for a different major version of + PostgreSQL. A magic block is required + as of PostgreSQL 8.2. To include a magic + block, write this in one (and only one) of your module source files, + after having included the header fmgr.h: + + + +#ifdef PG_MODULE_MAGIC +PG_MODULE_MAGIC; +#endif + + + + The #ifdef test can be omitted if your code doesn't + need to compile against pre-8.2 PostgreSQL + releases. + + + + + + Compiling and linking your code so that it can be dynamically + loaded into PostgreSQL always + requires special flags. See for a + detailed explanation of how to do it for your particular + operating system. + + + When allocating memory, use the @@ -1960,41 +1995,6 @@ concat_text(PG_FUNCTION_ARGS) error messages to this effect. - - - - To ensure your module is not loaded into an incompatible server, it - is recommended to include a magic block. This allows - the server to detect obvious incompatibilities, such as a module - compiled for a different major version of - PostgreSQL. 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 fmgr.h: - - - -#ifdef PG_MODULE_MAGIC -PG_MODULE_MAGIC; -#endif - - - - The #ifdef test can be omitted if your code doesn't - need to compile against pre-8.2 PostgreSQL - releases. - - - - - - Compiling and linking your code so that it can be dynamically - loaded into PostgreSQL always - requires special flags. See for a - detailed explanation of how to do it for your particular - operating system. - - diff --git a/src/backend/utils/fmgr/dfmgr.c b/src/backend/utils/fmgr/dfmgr.c index a54ca550dd7..0aacf2be995 100644 --- 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 index a0749a5fa6b..5b904cbad42 100644 --- 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 index 0ca31ac19c9..2ac798f81b6 100644 --- 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. */