Implement two new special variables in PL/PgSQL: SQLSTATE and SQLERRM.

These contain the SQLSTATE and error message of the current exception,
respectively. They are scope-local variables that are only defined
in exception handlers (so attempting to reference them outside an
exception handler is an error). Update the regression tests and the
documentation.

Also, do some minor related cleanup: export an unpack_sql_state()
function from the backend and use it to unpack a SQLSTATE into a
string, and add a free_var() function to pl_exec.c

Original patch from Pavel Stehule, review by Neil Conway.

1 files changed, 22 insertions, 16 deletions

diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 122a0a92a55..3e883887ee8 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -42,7 +42,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.159 2005/06/09 22:29:52 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.160 2005/06/10 16:23:10 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1482,6 +1482,26 @@ log_line_prefix(StringInfo buf)
 	}
 }
 
+/*
+ * Unpack MAKE_SQLSTATE code. Note that this returns a pointer to a
+ * static buffer.
+ */
+char *
+unpack_sql_state(int sql_state)
+{
+	static char	buf[12];
+	int			i;
+
+	for (i = 0; i < 5; i++)
+	{
+		buf[i] = PGUNSIXBIT(sql_state);
+		sql_state >>= 6;
+	}
+
+	buf[i] = '\0';
+	return buf;
+}
+
 
 /*
  * Write error report to server's log
@@ -1497,21 +1517,7 @@ send_message_to_server_log(ErrorData *edata)
 	appendStringInfo(&buf, "%s:  ", error_severity(edata->elevel));
 
 	if (Log_error_verbosity >= PGERROR_VERBOSE)
-	{
-		/* unpack MAKE_SQLSTATE code */
-		char		tbuf[12];
-		int			ssval;
-		int			i;
-
-		ssval = edata->sqlerrcode;
-		for (i = 0; i < 5; i++)
-		{
-			tbuf[i] = PGUNSIXBIT(ssval);
-			ssval >>= 6;
-		}
-		tbuf[i] = '\0';
-		appendStringInfo(&buf, "%s: ", tbuf);
-	}
+		appendStringInfo(&buf, "%s: ", unpack_sql_state(edata->sqlerrcode));
 
 	if (edata->message)
 		append_with_tabs(&buf, edata->message);