Generate VHDL for no-op statements

tgt-vhdl/stmt.cc

@@ -117,6 +117,16 @@ static int draw_block(vhdl_process *proc, ivl_statement_t stmt)
    return 0;
 }
 
+/*
+ * A no-op statement. This corresponds to a `null' statement in
+ * VHDL.
+ */
+static int draw_noop(vhdl_process *proc, ivl_statement_t stmt)
+{
+   proc->add_stmt(new vhdl_null_stmt());
+   return 0;
+}
+
 /*
  * Generate VHDL statements for the given Verilog statement and
  * add them to the given VHDL process.
@@ -128,6 +138,8 @@ int draw_stmt(vhdl_process *proc, ivl_statement_t stmt)
       return draw_stask(proc, stmt);
    case IVL_ST_BLOCK:
       return draw_block(proc, stmt);
+   case IVL_ST_NOOP:
+      return draw_noop(proc, stmt);
    default:
       error("No VHDL translation for statement at %s:%d (type = %d)",
             ivl_stmt_file(stmt), ivl_stmt_lineno(stmt),

tgt-vhdl/vhdl_element.cc

@@ -363,3 +363,8 @@ void vhdl_const_string::emit(std::ofstream &of, int level) const
    // isn't always strictly necessary) 
    of << "String'(\"" << value_ << "\")";
 }
+
+void vhdl_null_stmt::emit(std::ofstream &of, int level) const
+{
+   of << "null;";
+}

tgt-vhdl/vhdl_element.hh

@@ -142,6 +142,12 @@ public:
 };
 
 
+class vhdl_null_stmt : public vhdl_seq_stmt {
+public:
+   void emit(std::ofstream &of, int level) const;
+};
+
+
 /*
  * A procedure call. Which is a statement, unlike a function
  * call which is an expression.