This patch makes a minor cleanup to the implementation of PERFORM in

PL/PgSQL. Previously, it had been bundled together with the assign
statement implementation, for some reason that wasn't clear to me
(they certainly don't share any code with one another). So I separated
them and made PERFORM a statement like any other. No changes in
functionality.

Along the way, I added some regression tests for PERFORM, added a
bunch more SGML tags to the PL/PgSQL docs, and removed an obsolete
comment relating to the implementation of RETURN NEXT.

Neil Conway

src/test/regress/expected/plpgsql.out

@@ -1733,3 +1733,54 @@ SELECT * FROM test_ret_rec_dyn(5) AS (a int, b numeric, c text);
  50 | 5 | xxx
 (1 row)
 
+--
+-- test PERFORM
+--
+create table perform_test (
+	a	INT,
+	b	INT
+);
+create function simple_func(int) returns boolean as '
+BEGIN
+	IF $1 < 20 THEN
+		INSERT INTO perform_test VALUES ($1, $1 + 10);
+		RETURN TRUE;
+	ELSE
+		RETURN FALSE;
+	END IF;
+END;' language 'plpgsql';
+create function perform_test_func() returns void as '
+BEGIN
+	IF FOUND then
+		INSERT INTO perform_test VALUES (100, 100);
+	END IF;
+
+	PERFORM simple_func(5);
+
+	IF FOUND then
+		INSERT INTO perform_test VALUES (100, 100);
+	END IF;
+
+	PERFORM simple_func(50);
+
+	IF FOUND then
+		INSERT INTO perform_test VALUES (100, 100);
+	END IF;
+
+	RETURN;
+END;' language 'plpgsql';
+SELECT perform_test_func();
+ perform_test_func 
+-------------------
+ 
+(1 row)
+
+SELECT * FROM perform_test;
+  a  |  b  
+-----+-----
+   5 |  15
+ 100 | 100
+ 100 | 100
+(3 rows)
+
+drop table perform_test;

src/test/regress/sql/plpgsql.sql

@@ -1559,3 +1559,48 @@ END;' language 'plpgsql';
 
 SELECT * FROM test_ret_rec_dyn(1500) AS (a int, b int, c int);
 SELECT * FROM test_ret_rec_dyn(5) AS (a int, b numeric, c text);
+
+--
+-- test PERFORM
+--
+
+create table perform_test (
+	a	INT,
+	b	INT
+);
+
+create function simple_func(int) returns boolean as '
+BEGIN
+	IF $1 < 20 THEN
+		INSERT INTO perform_test VALUES ($1, $1 + 10);
+		RETURN TRUE;
+	ELSE
+		RETURN FALSE;
+	END IF;
+END;' language 'plpgsql';
+
+create function perform_test_func() returns void as '
+BEGIN
+	IF FOUND then
+		INSERT INTO perform_test VALUES (100, 100);
+	END IF;
+
+	PERFORM simple_func(5);
+
+	IF FOUND then
+		INSERT INTO perform_test VALUES (100, 100);
+	END IF;
+
+	PERFORM simple_func(50);
+
+	IF FOUND then
+		INSERT INTO perform_test VALUES (100, 100);
+	END IF;
+
+	RETURN;
+END;' language 'plpgsql';
+
+SELECT perform_test_func();
+SELECT * FROM perform_test;
+
+drop table perform_test;