/*------------------------------------------------------------------------- * * linux.c *	  Dynamic Loader for Postgres for Linux, generated from those for *	  Ultrix. * *	  You need to install the dld library on your Linux system! * * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION *	  $Header: /cvsroot/pgsql/src/backend/port/dynloader/linux.c,v 1.26 2003/08/04 02:40:02 momjian Exp $ * *------------------------------------------------------------------------- */#include "postgres.h"#ifdef HAVE_DLD_H#include <dld.h>#endif#include "dynloader.h"#include "miscadmin.h"#ifndef HAVE_DLOPENvoid *pg_dlopen(char *filename){#ifndef HAVE_DLD_H	elog(ERROR, "dynamic load not supported");	return NULL;#else	static int	dl_initialized = 0;	/*	 * initializes the dynamic loader with the executable's pathname.	 * (only needs to do this the first time pg_dlopen is called.)	 */	if (!dl_initialized)	{		if (dld_init(dld_find_executable(pg_pathname)))			return NULL;		/*		 * if there are undefined symbols, we want dl to search from the		 * following libraries also.		 */		dl_initialized = 1;	}	/*	 * link the file, then check for undefined symbols!	 */	if (dld_link(filename))		return NULL;	/*	 * If undefined symbols: try to link with the C and math libraries!	 * This could be smarter, if the dynamic linker was able to handle	 * shared libs!	 */	if (dld_undefined_sym_count > 0)	{		if (dld_link("/usr/lib/libc.a"))		{			elog(WARNING, "could not link C library");			return NULL;		}		if (dld_undefined_sym_count > 0)		{			if (dld_link("/usr/lib/libm.a"))			{				elog(WARNING, "could not link math library");				return NULL;			}			if (dld_undefined_sym_count > 0)			{				int			count = dld_undefined_sym_count;				char	  **list = dld_list_undefined_sym();				/* list the undefined symbols, if any */				do				{					elog(WARNING, "\"%s\" is undefined", *list);					list++;					count--;				} while (count > 0);				dld_unlink_by_file(filename, 1);				return NULL;			}		}	}	return (void *) strdup(filename);#endif}PGFunctionpg_dlsym(void *handle, char *funcname){#ifndef HAVE_DLD_H	return NULL;#else	return (PGFunction) dld_get_func((funcname));#endif}voidpg_dlclose(void *handle){#ifndef HAVE_DLD_H#else	dld_unlink_by_file(handle, 1);	free(handle);#endif}char *pg_dlerror(void){#ifndef HAVE_DLD_H	return "dynaloader unspported";#else	return dld_strerror(dld_errno);#endif}#endif   /* !HAVE_DLOPEN */