Add VHDL syntax element for `with .. select' statement

This will be used to implement combinatorial UDPs

tgt-vhdl/vhdl_syntax.cc

@@ -888,3 +888,41 @@ void vhdl_param_decl::emit(std::ostream &of, int level) const
    of << name_ << " : ";
    type_->emit(of, level);
 }
+
+vhdl_with_select_stmt::~vhdl_with_select_stmt()
+{
+   delete test_;
+
+   for (when_list_t::const_iterator it = whens_.begin();
+        it != whens_.end();
+        ++it) {
+      delete (*it).value;
+      delete (*it).cond;
+   }
+}
+
+void vhdl_with_select_stmt::emit(std::ostream &of, int level) const
+{
+   emit_comment(of, level);
+   
+   of << "with ";
+   test_->emit(of, level);
+   of << " select";
+   newline(of, indent(level));
+
+   when_list_t::const_iterator it = whens_.begin();
+   while (it != whens_.end()) {
+      if (++it != whens_.end()) {
+         of << ",";
+         newline(of, indent(level));
+      }
+      else
+         of << ";";
+   }
+}
+
+void vhdl_with_select_stmt::add_condition(vhdl_expr *value, vhdl_expr *cond)
+{
+   when_part_t when = { value, cond };
+   whens_.push_back(when);
+}

tgt-vhdl/vhdl_syntax.hh

@@ -254,6 +254,16 @@ public:
 
 typedef std::list<vhdl_conc_stmt*> conc_stmt_list_t;
 
+/*
+ * A '<value> when <cond>' clause that appears in several
+ * statement types.
+ */
+struct when_part_t {
+   vhdl_expr *value, *cond;
+};
+typedef std::list<when_part_t> when_list_t;
+
+
 /*
  * A concurrent signal assignment (i.e. not part of a process).
  * Can have any number of `when' clauses, in which case the original
@@ -272,13 +282,23 @@ private:
    vhdl_var_ref *lhs_;
    vhdl_expr *rhs_;
    vhdl_expr *after_;
-
-   struct when_part_t {
-      vhdl_expr *value, *cond;
-   };
-   std::list<when_part_t> whens_;
+   when_list_t whens_;
 };
 
+
+class vhdl_with_select_stmt : public vhdl_conc_stmt {
+public:
+   vhdl_with_select_stmt(vhdl_expr *test) : test_(test) {}
+   ~vhdl_with_select_stmt();
+   
+   void emit(std::ostream &of, int level) const;
+   void add_condition(vhdl_expr *value, vhdl_expr *cond);
+private:
+   vhdl_expr *test_;
+   when_list_t whens_;
+};
+
+
 /*
  * Any sequential statement in a process.
  */