Check number of parameters in RAISE statement at compile time.

The number of % parameter markers in RAISE statement should match the number
of parameters given. We used to check that at execution time, but we have
all the information needed at compile time, so let's check it at compile
time instead. It's generally better to find mistakes earlier.

Marko Tiikkaja, reviewed by Fabien Coelho

Author: hlinnaka

doc/src/sgml/plpgsql.sgml

@@ -3403,6 +3403,9 @@ RAISE ;
     Inside the format string, <literal>%</literal> is replaced by the
     string representation of the next optional argument's value. Write
     <literal>%%</literal> to emit a literal <literal>%</literal>.
+    The number of arguments must match the number of <literal>%</>
+    placeholders in the format string, or an error is raised during
+    the compilation of the function.
    </para>
 
    <para>

src/pl/plpgsql/src/pl_exec.c

@@ -2939,10 +2939,9 @@ exec_stmt_raise(PLpgSQL_execstate *estate, PLpgSQL_stmt_raise *stmt)
 					continue;
 				}
 
+				/* should have been checked at compile time */
 				if (current_param == NULL)
-					ereport(ERROR,
-							(errcode(ERRCODE_SYNTAX_ERROR),
-						  errmsg("too few parameters specified for RAISE")));
+					elog(ERROR, "unexpected RAISE parameter list length");
 
 				paramvalue = exec_eval_expr(estate,
 									  (PLpgSQL_expr *) lfirst(current_param),
@@ -2963,14 +2962,9 @@ exec_stmt_raise(PLpgSQL_execstate *estate, PLpgSQL_stmt_raise *stmt)
 				appendStringInfoChar(&ds, cp[0]);
 		}
 
-		/*
-		 * If more parameters were specified than were required to process the
-		 * format string, throw an error
-		 */
+		/* should have been checked at compile time */
 		if (current_param != NULL)
-			ereport(ERROR,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("too many parameters specified for RAISE")));
+			elog(ERROR, "unexpected RAISE parameter list length");
 
 		err_message = ds.data;
 		/* No pfree(ds.data), the pfree(err_message) does it */

src/pl/plpgsql/src/pl_gram.y

@@ -106,6 +106,7 @@ static	void			 check_labels(const char *start_label,
 static	PLpgSQL_expr	*read_cursor_args(PLpgSQL_var *cursor,
 										  int until, const char *expected);
 static	List			*read_raise_options(void);
+static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 
 %}
 
@@ -1849,6 +1850,8 @@ stmt_raise		: K_RAISE
 								new->options = read_raise_options();
 						}
 
+						check_raise_parameters(new);
+
 						$$ = (PLpgSQL_stmt *)new;
 					}
 				;
@@ -3767,6 +3770,41 @@ read_raise_options(void)
 	return result;
 }
 
+/*
+ * Check that the number of parameter placeholders in the message matches the
+ * number of parameters passed to it, if a message was given.
+ */
+static void
+check_raise_parameters(PLpgSQL_stmt_raise *stmt)
+{
+	char	   *cp;
+	int			expected_nparams = 0;
+
+	if (stmt->message == NULL)
+		return;
+
+	for (cp = stmt->message; *cp; cp++)
+	{
+		if (cp[0] == '%')
+		{
+			/* ignore literal % characters */
+			if (cp[1] == '%')
+				cp++;
+			else
+				expected_nparams++;
+		}
+	}
+
+	if (expected_nparams < list_length(stmt->params))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				errmsg("too many parameters specified for RAISE")));
+	if (expected_nparams > list_length(stmt->params))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				errmsg("too few parameters specified for RAISE")));
+}
+
 /*
  * Fix up CASE statement
  */

src/test/regress/expected/plpgsql.out

@@ -2446,18 +2446,29 @@ begin
     return $1;
 end;
 $$ language plpgsql;
-select raise_test1(5);
 ERROR:  too many parameters specified for RAISE
-CONTEXT:  PL/pgSQL function raise_test1(integer) line 3 at RAISE
+CONTEXT:  compilation of PL/pgSQL function "raise_test1" near line 3
 create function raise_test2(int) returns int as $$
 begin
     raise notice 'This message has too few parameters: %, %, %', $1, $1;
     return $1;
 end;
 $$ language plpgsql;
-select raise_test2(10);
 ERROR:  too few parameters specified for RAISE
-CONTEXT:  PL/pgSQL function raise_test2(integer) line 3 at RAISE
+CONTEXT:  compilation of PL/pgSQL function "raise_test2" near line 3
+create function raise_test3(int) returns int as $$
+begin
+    raise notice 'This message has no parameters (despite having %% signs in it)!';
+    return $1;
+end;
+$$ language plpgsql;
+select raise_test3(1);
+NOTICE:  This message has no parameters (despite having % signs in it)!
+ raise_test3 
+-------------
+           1
+(1 row)
+
 -- Test re-RAISE inside a nested exception block.  This case is allowed
 -- by Oracle's PL/SQL but was handled differently by PG before 9.1.
 CREATE FUNCTION reraise_test() RETURNS void AS $$

src/test/regress/sql/plpgsql.sql

@@ -2078,16 +2078,21 @@ begin
 end;
 $$ language plpgsql;
 
-select raise_test1(5);
-
 create function raise_test2(int) returns int as $$
 begin
     raise notice 'This message has too few parameters: %, %, %', $1, $1;
     return $1;
 end;
 $$ language plpgsql;
 
-select raise_test2(10);
+create function raise_test3(int) returns int as $$
+begin
+    raise notice 'This message has no parameters (despite having %% signs in it)!';
+    return $1;
+end;
+$$ language plpgsql;
+
+select raise_test3(1);
 
 -- Test re-RAISE inside a nested exception block.  This case is allowed
 -- by Oracle's PL/SQL but was handled differently by PG before 9.1.