Postgres95 1.01 Distribution - Virgin Sources

src/backend/port/ultrix4/dynloader.c

@@ -0,0 +1,68 @@
+/*-------------------------------------------------------------------------
+ *
+ * dynloader.c--
+ *    This dynamic loader uses Andrew Yu's libdl-1.0 package for Ultrix 4.x.
+ *    (Note that pg_dlsym and pg_dlclose are actually macros defined in
+ *    "port-protos.h".)
+ *    
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *    $Header: /cvsroot/pgsql/src/backend/port/ultrix4/Attic/dynloader.c,v 1.1.1.1 1996/07/09 06:21:45 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <stdio.h>
+#include "dl.h"
+#include "c.h"
+#include "fmgr.h"
+#include "port-protos.h"
+#include "utils/elog.h"
+
+extern char pg_pathname[];
+
+void *
+pg_dlopen(char *filename)
+{
+    static int dl_initialized= 0;
+    void *handle;
+
+    /*
+     * 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 (!dl_init(pg_pathname)) {
+	    return NULL;
+	}
+	/*
+	 * if there are undefined symbols, we want dl to search from the
+	 * following libraries also.
+	 */
+	dl_setLibraries("/usr/lib/libm_G0.a:/usr/lib/libc_G0.a");
+	dl_initialized= 1;
+    }
+
+    /*
+     * open the file. We do the symbol resolution right away so that we
+     * will know if there are undefined symbols. (This is in fact the
+     * same semantics as "ld -A". ie. you cannot have undefined symbols.
+     */
+    if ((handle=dl_open(filename, DL_NOW))==NULL) {
+	int count;
+	char **list= dl_undefinedSymbols(&count);
+
+	/* list the undefined symbols, if any */
+	if(count) {
+	    elog(NOTICE, "dl: Undefined:");
+	    while(*list) {
+		elog(NOTICE, "  %s", *list);
+		list++;
+	    }
+	}
+    }
+
+    return (void *)handle;
+}
+