xorp

code_generator.hh

00001 // -*- c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t -*-
00002 // vim:set sts=4 ts=8:
00003 
00004 // Copyright (c) 2001-2011 XORP, Inc and Others
00005 //
00006 // This program is free software; you can redistribute it and/or modify
00007 // it under the terms of the GNU General Public License, Version 2, June
00008 // 1991 as published by the Free Software Foundation. Redistribution
00009 // and/or modification of this program under the terms of any other
00010 // version of the GNU General Public License is not permitted.
00011 // 
00012 // This program is distributed in the hope that it will be useful, but
00013 // WITHOUT ANY WARRANTY; without even the implied warranty of
00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. For more details,
00015 // see the GNU General Public License, Version 2, a copy of which can be
00016 // found in the XORP LICENSE.gpl file.
00017 // 
00018 // XORP Inc, 2953 Bunker Hill Lane, Suite 204, Santa Clara, CA 95054, USA;
00019 // http://xorp.net
00020 
00021 // $XORP: xorp/policy/code_generator.hh,v 1.12 2008/10/02 21:57:57 bms Exp $
00022 
00023 #ifndef __POLICY_CODE_GENERATOR_HH__
00024 #define __POLICY_CODE_GENERATOR_HH__
00025 
00026 
00027 
00028 
00029 #include "policy/common/varrw.hh"
00030 #include "policy/common/policy_exception.hh"
00031 #include "var_map.hh"
00032 #include "visitor.hh"
00033 #include "code.hh"
00034 #include "policy_statement.hh"
00035 #include "node.hh"
00036 
00042 class CodeGenerator : public Visitor {
00043 public:
00050     class CodeGeneratorErr : public PolicyException {
00051     public:
00052         CodeGeneratorErr(const char* file, size_t line, 
00053              const string& init_why = "")
00054             : PolicyException("CodeGeneratorErr", file, line, init_why) {}   
00055     };
00056 
00057     // used by source match code generator.
00058     CodeGenerator(const VarMap& varmap, PolicyMap& pmap);
00059 
00069     CodeGenerator(const string& proto, const filter::Filter& filter,
00070           const VarMap& varmap, PolicyMap& pmap);
00071 
00078     CodeGenerator(const string& proto, const VarMap& varmap, PolicyMap& pmap);
00079 
00080     virtual ~CodeGenerator();
00081 
00082     const Element* visit(NodeUn& node);
00083     const Element* visit(NodeBin& node);
00084     const Element* visit(NodeAssign& node);
00085     const Element* visit(NodeElem& node);
00086     const Element* visit(NodeVar& node);
00087     const Element* visit(NodeSet& node);
00088     const Element* visit(NodeAccept& node);
00089     const Element* visit(NodeReject& node);
00090     const Element* visit(PolicyStatement& policy); 
00091     const Element* visit(Term& policy); 
00092     const Element* visit(NodeProto& policy); 
00093     const Element* visit(NodeNext& node);
00094     const Element* visit(NodeSubr& node);
00095 
00099     const Code& code();
00100 
00101 protected:
00102     // may not overload virtual functions =(
00103     // yes it is a triple dispatch... but we will get there eventually =D
00104     virtual const Element* visit_policy(PolicyStatement& policy);
00105     virtual const Element* visit_term(Term& term);
00106     virtual const Element* visit_proto(NodeProto& node);
00107     virtual const string&  protocol();
00108 
00109     Code        _code;
00110     ostringstream   _os;
00111     const VarMap&   _varmap;
00112     PolicyMap&      _pmap;
00113     bool        _subr;
00114 
00115 private:
00116     string      _protocol;
00117 };
00118 
00119 #endif // __POLICY_CODE_GENERATOR_HH__
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