iverilog/elab_pexpr.cc

124 lines
3.6 KiB
C++

/*
* Copyright (c) 2000 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) && !defined(macintosh)
#ident "$Id: elab_pexpr.cc,v 1.3 2000/03/12 18:22:11 steve Exp $"
#endif
# include "PExpr.h"
NetExpr*PExpr::elaborate_pexpr(Design*des, NetScope*sc) const
{
cerr << get_line() << ": error: invalid parameter expression: "
<< *this << endl;
des->errors += 1;
return 0;
}
/*
* Binary operators have sub-expressions that must be elaborated as
* parameter expressions. If either of them fail, then give up. Once
* they are taken care of, make the base object just as in any other
* expression.
*/
NetExpr*PEBinary::elaborate_pexpr (Design*des, NetScope*scope) const
{
NetExpr*lp = left_->elaborate_pexpr(des, scope);
NetExpr*rp = right_->elaborate_pexpr(des, scope);
if ((lp == 0) || (rp == 0)) {
delete lp;
delete rp;
return 0;
}
NetEBinary*tmp = elaborate_expr_base_(des, lp, rp);
return tmp;
}
/*
* Parameter expressions may reference other parameters, but only in
* the current scope. Preserve the parameter reference in the
* parameter expression I'm generating, instead of evaluating it now,
* because the referenced parameter may yet be overridden.
*/
NetExpr*PEIdent::elaborate_pexpr(Design*des, NetScope*scope) const
{
const NetExpr*ex = scope->get_parameter(text_);
if (ex == 0) {
cerr << get_line() << ": error: identifier ``" << text_ <<
"'' is not a parameter in " << scope->name() << "." << endl;
des->errors += 1;
return 0;
}
NetExpr*res = new NetEParam(des, scope, text_);
assert(res);
return res;
}
/*
* Simple numbers can be elaborated by the elaborate_expr method.
*/
NetExpr*PENumber::elaborate_pexpr(Design*des, NetScope*sc) const
{
return elaborate_expr(des, sc);
}
NetExpr*PEUnary::elaborate_pexpr (Design*des, NetScope*scope) const
{
NetExpr*ip = expr_->elaborate_pexpr(des, scope);
if (ip == 0) return 0;
/* Should we evaluate expressions ahead of time,
* just like in PEBinary::elaborate_expr() ?
*/
NetEUnary*tmp;
switch (op_) {
default:
tmp = new NetEUnary(op_, ip);
tmp->set_line(*this);
break;
case '~':
tmp = new NetEUBits(op_, ip);
tmp->set_line(*this);
break;
}
return tmp;
}
/*
* $Log: elab_pexpr.cc,v $
* Revision 1.3 2000/03/12 18:22:11 steve
* Binary and unary operators in parameter expressions.
*
* Revision 1.2 2000/03/12 04:35:22 steve
* Allow parameter identifiers in parameter expressions.
*
* Revision 1.1 2000/03/08 04:36:53 steve
* Redesign the implementation of scopes and parameters.
* I now generate the scopes and notice the parameters
* in a separate pass over the pform. Once the scopes
* are generated, I can process overrides and evalutate
* paremeters before elaboration begins.
*
*/