PExpr.cc

/*
 * Copyright (c) 1998 Stephen Williams <steve@icarus.com>
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */
#if !defined(WINNT)
#ident "$Id: PExpr.cc,v 1.7 1999/07/22 02:05:20 steve Exp $"
#endif

# include  "PExpr.h"
# include  "Module.h"
# include  <typeinfo>

PExpr::~PExpr()
{
}

bool PExpr::is_the_same(const PExpr*that) const
{
      return typeid(this) == typeid(that);
}

bool PExpr::is_constant(Module*) const
{
      return false;
}

bool PEBinary::is_constant(Module*mod) const
{
      return left_->is_constant(mod) && right_->is_constant(mod);
}

bool PEConcat::is_constant(Module *mod) const
{
      bool constant = repeat_->is_constant(mod);
      for (unsigned i = 0; constant && i < parms_.count(); ++i) {
	    constant = constant && parms_[i]->is_constant(mod);
      }
      return constant;
}

PEConcat::~PEConcat()
{
      delete repeat_;
}

/*
 * An identifier can be in a constant expresion if (and only if) it is
 * a parameter.
 */
bool PEIdent::is_constant(Module*mod) const
{
      map<string,PExpr*>::const_iterator cur = mod->parameters.find(text_);
      return cur != mod->parameters.end();
}

bool PENumber::is_the_same(const PExpr*that) const
{
      const PENumber*obj = dynamic_cast<const PENumber*>(that);
      if (obj == 0)
	    return false;

      return *value_ == *obj->value_;
}

bool PENumber::is_constant(Module*) const
{
      return true;
}

bool PEString::is_constant(Module*) const
{
      return true;
}

PETernary::PETernary(PExpr*e, PExpr*t, PExpr*f)
: expr_(e), tru_(t), fal_(f)
{
}

PETernary::~PETernary()
{
}

bool PETernary::is_constant(Module*) const
{
      return false;
}

/*
 * $Log: PExpr.cc,v $
 * Revision 1.7  1999/07/22 02:05:20  steve
 *  is_constant method for PEConcat.
 *
 * Revision 1.6  1999/07/17 19:50:59  steve
 *  netlist support for ternary operator.
 *
 * Revision 1.5  1999/06/16 03:13:29  steve
 *  More syntax parse with sorry stubs.
 *
 * Revision 1.4  1999/06/10 04:03:52  steve
 *  Add support for the Ternary operator,
 *  Add support for repeat concatenation,
 *  Correct some seg faults cause by elaboration
 *  errors,
 *  Parse the casex anc casez statements.
 *
 * Revision 1.3  1999/05/16 05:08:42  steve
 *  Redo constant expression detection to happen
 *  after parsing.
 *
 *  Parse more operators and expressions.
 *
 * Revision 1.2  1998/11/11 00:01:51  steve
 *  Check net ranges in declarations.
 *
 * Revision 1.1  1998/11/03 23:28:53  steve
 *  Introduce verilog to CVS.
 *
 */