1 files changed, 194 insertions, 0 deletions
diff --git a/src/bin/pg_upgrade/function.c b/src/bin/pg_upgrade/function.c
new file mode 100644
index 0000000..dc8800c
--- /dev/null
+++ b/src/bin/pg_upgrade/function.c
@@ -0,0 +1,194 @@
+/*
+ *	function.c
+ *
+ *	server-side function support
+ *
+ *	Copyright (c) 2010-2023, PostgreSQL Global Development Group
+ *	src/bin/pg_upgrade/function.c
+ */
+
+#include "postgres_fe.h"
+
+#include "access/transam.h"
+#include "catalog/pg_language_d.h"
+#include "pg_upgrade.h"
+
+/*
+ * qsort comparator for pointers to library names
+ *
+ * We sort first by name length, then alphabetically for names of the
+ * same length, then database array index.  This is to ensure that, eg,
+ * "hstore_plpython" sorts after both "hstore" and "plpython"; otherwise
+ * transform modules will probably fail their LOAD tests.  (The backend
+ * ought to cope with that consideration, but it doesn't yet, and even
+ * when it does it'll still be a good idea to have a predictable order of
+ * probing here.)
+ */
+static int
+library_name_compare(const void *p1, const void *p2)
+{
+	const char *str1 = ((const LibraryInfo *) p1)->name;
+	const char *str2 = ((const LibraryInfo *) p2)->name;
+	int			slen1 = strlen(str1);
+	int			slen2 = strlen(str2);
+	int			cmp = strcmp(str1, str2);
+
+	if (slen1 != slen2)
+		return slen1 - slen2;
+	if (cmp != 0)
+		return cmp;
+	else
+		return ((const LibraryInfo *) p1)->dbnum -
+			((const LibraryInfo *) p2)->dbnum;
+}
+
+
+/*
+ * get_loadable_libraries()
+ *
+ *	Fetch the names of all old libraries containing C-language functions.
+ *	We will later check that they all exist in the new installation.
+ */
+void
+get_loadable_libraries(void)
+{
+	PGresult  **ress;
+	int			totaltups;
+	int			dbnum;
+
+	ress = (PGresult **) pg_malloc(old_cluster.dbarr.ndbs * sizeof(PGresult *));
+	totaltups = 0;
+
+	/* Fetch all library names, removing duplicates within each DB */
+	for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
+	{
+		DbInfo	   *active_db = &old_cluster.dbarr.dbs[dbnum];
+		PGconn	   *conn = connectToServer(&old_cluster, active_db->db_name);
+
+		/*
+		 * Fetch all libraries containing non-built-in C functions in this DB.
+		 */
+		ress[dbnum] = executeQueryOrDie(conn,
+										"SELECT DISTINCT probin "
+										"FROM pg_catalog.pg_proc "
+										"WHERE prolang = %u AND "
+										"probin IS NOT NULL AND "
+										"oid >= %u;",
+										ClanguageId,
+										FirstNormalObjectId);
+		totaltups += PQntuples(ress[dbnum]);
+
+		PQfinish(conn);
+	}
+
+	os_info.libraries = (LibraryInfo *) pg_malloc(totaltups * sizeof(LibraryInfo));
+	totaltups = 0;
+
+	for (dbnum = 0; dbnum < old_cluster.dbarr.ndbs; dbnum++)
+	{
+		PGresult   *res = ress[dbnum];
+		int			ntups;
+		int			rowno;
+
+		ntups = PQntuples(res);
+		for (rowno = 0; rowno < ntups; rowno++)
+		{
+			char	   *lib = PQgetvalue(res, rowno, 0);
+
+			os_info.libraries[totaltups].name = pg_strdup(lib);
+			os_info.libraries[totaltups].dbnum = dbnum;
+
+			totaltups++;
+		}
+		PQclear(res);
+	}
+
+	pg_free(ress);
+
+	os_info.num_libraries = totaltups;
+}
+
+
+/*
+ * check_loadable_libraries()
+ *
+ *	Check that the new cluster contains all required libraries.
+ *	We do this by actually trying to LOAD each one, thereby testing
+ *	compatibility as well as presence.
+ */
+void
+check_loadable_libraries(void)
+{
+	PGconn	   *conn = connectToServer(&new_cluster, "template1");
+	int			libnum;
+	int			was_load_failure = false;
+	FILE	   *script = NULL;
+	char		output_path[MAXPGPATH];
+
+	prep_status("Checking for presence of required libraries");
+
+	snprintf(output_path, sizeof(output_path), "%s/%s",
+			 log_opts.basedir, "loadable_libraries.txt");
+
+	/*
+	 * Now we want to sort the library names into order.  This avoids multiple
+	 * probes of the same library, and ensures that libraries are probed in a
+	 * consistent order, which is important for reproducible behavior if one
+	 * library depends on another.
+	 */
+	qsort(os_info.libraries, os_info.num_libraries,
+		  sizeof(LibraryInfo), library_name_compare);
+
+	for (libnum = 0; libnum < os_info.num_libraries; libnum++)
+	{
+		char	   *lib = os_info.libraries[libnum].name;
+		int			llen = strlen(lib);
+		char		cmd[7 + 2 * MAXPGPATH + 1];
+		PGresult   *res;
+
+		/* Did the library name change?  Probe it. */
+		if (libnum == 0 || strcmp(lib, os_info.libraries[libnum - 1].name) != 0)
+		{
+			strcpy(cmd, "LOAD '");
+			PQescapeStringConn(conn, cmd + strlen(cmd), lib, llen, NULL);
+			strcat(cmd, "'");
+
+			res = PQexec(conn, cmd);
+
+			if (PQresultStatus(res) != PGRES_COMMAND_OK)
+			{
+				was_load_failure = true;
+
+				if (script == NULL && (script = fopen_priv(output_path, "w")) == NULL)
+					pg_fatal("could not open file \"%s\": %s",
+							 output_path, strerror(errno));
+				fprintf(script, _("could not load library \"%s\": %s"),
+						lib,
+						PQerrorMessage(conn));
+			}
+			else
+				was_load_failure = false;
+
+			PQclear(res);
+		}
+
+		if (was_load_failure)
+			fprintf(script, _("In database: %s\n"),
+					old_cluster.dbarr.dbs[os_info.libraries[libnum].dbnum].db_name);
+	}
+
+	PQfinish(conn);
+
+	if (script)
+	{
+		fclose(script);
+		pg_log(PG_REPORT, "fatal");
+		pg_fatal("Your installation references loadable libraries that are missing from the\n"
+				 "new installation.  You can add these libraries to the new installation,\n"
+				 "or remove the functions using them from the old installation.  A list of\n"
+				 "problem libraries is in the file:\n"
+				 "    %s", output_path);
+	}
+	else
+		check_ok();
+}