From b376115e15bf1860364d069e09d070bbd646f142 Mon Sep 17 00:00:00 2001
From: Pawel Szostek <pawel.szostek@gmail.com>
Date: Tue, 5 Jul 2011 15:58:26 +0200
Subject: [PATCH] Add parser support for VHDL's null statements

Handle null statements in sequences of statements.
If a null is encountered, it is omitted and not
added to the list of statements.
---
 vhdlpp/parse.y | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/vhdlpp/parse.y b/vhdlpp/parse.y
index 6a51ffea4..c61b3d984 100644
--- a/vhdlpp/parse.y
+++ b/vhdlpp/parse.y
@@ -1375,12 +1375,14 @@ selected_names_use
 sequence_of_statements
   : sequence_of_statements sequential_statement
       { std::list<SequentialStmt*>*tmp = $1;
-	tmp->push_back($2);
+    if($2)
+        tmp->push_back($2);
 	$$ = tmp;
       }
   | sequential_statement
       { std::list<SequentialStmt*>*tmp = new std::list<SequentialStmt*>;
-	tmp->push_back($1);
+    if($1)
+        tmp->push_back($1);
 	$$ = tmp;
       }
   ;
@@ -1390,6 +1392,7 @@ sequential_statement
   | signal_assignment_statement { $$ = $1; }
   | case_statement { $$ = $1; }
   | procedure_call_statement { $$ = $1; }
+  | K_null ';' { $$ = 0; }
   ;
 
 shift_expression : simple_expression { $$ = $1; } ;