//- expressions -------------------------------------------------------------
public IdentExprNode getExprIdentNode(String id)
{
OILNode idsym = symbolTable.findSymbol(id);
IdentExprNode node = new IdentExprNode(idsym);
return(node);
}
// switch (node.nodetype)
// {
// case NodeType.VarDeclar:
// codeGen.evalVarDeclaration(node);
// break;
// case NodeType.PrimaryId:
// codeGen.evalPrimaryId(node);
// break;
// case NodeType.PrimaryConst:
// codeGen.evalPrimaryConst(node);
// break;
// case NodeType.AddExpr:
// codeGen.evalAddExpression(node);
// break;
public void genIdentExpression(IdentExprNode expr)
{
OILNode lsym = expr.idsym;
switch (lsym.type)
{
case OILType.ParamDecl:
uint pofs = ((CGParamDeclNode)(lsym.cgnode)).addr;
assembly.addLine("mov eax, [ebp+" + pofs + "]");
break;
case OILType.VarDecl:
uint vofs = ((CGVarDeclNode)(lsym.cgnode)).addr;
assembly.addLine("mov eax, [ebp-" + vofs + "]");
break;
default:
break;
}
assembly.addLine("push eax"); //var value --> top of stack
}
//only supporting simple assignments (=) now, not compound assignments (ie +=, *= etc)
public void genAssignmentExpression(AssignExprNode expr)
{
genExpression(expr.rhs);
assembly.addLine("pop eax"); //rhs --> eax
IdentExprNode lvar = (IdentExprNode)expr.lhs;
OILNode lsym = lvar.idsym;
switch (lsym.type)
{
case OILType.ParamDecl:
uint pofs = ((CGParamDeclNode)(lsym.cgnode)).addr;
assembly.addLine("mov [ebp+" + pofs + "],eax");
break;
case OILType.VarDecl:
uint vofs = ((CGVarDeclNode)(lsym.cgnode)).addr;
assembly.addLine("mov [ebp-" + vofs + "],eax");
break;
default:
break;
}
}