public SymbolTable(Parser parser)
{
this.parser = parser;
topScope = null;
curLevel = -1;
undefObj = new Obj();
undefObj.name = "undef"; undefObj.type = undef; undefObj.kind = var; undefObj.sort = scalar; undefObj.constval = "0"; undefObj.length = 1;
undefObj.adr = 0; undefObj.level = 0; undefObj.next = null;
}
using System;
// create a new object node in the current scope
public Obj NewObj(string name, int kind, int type, int sort, string constval, int length)
{
Obj p, last, obj = new Obj();
obj.name = name; obj.kind = kind; obj.type = type; obj.sort = sort; obj.constval = constval; obj.length = length;
obj.level = curLevel;
p = topScope.locals; last = null;
while (p != null) {
if (p.name == name) parser.SemErr("name declared twice");
last = p; p = p.next;
}
if (last == null) topScope.locals = obj; else last.next = obj;
if (kind == var && sort == scalar) obj.adr = topScope.nextAdr++;
if (kind == var && sort == array) {obj.adr = topScope.nextAdr++; topScope.nextAdr = topScope.nextAdr + length; }
return obj;
}
// close the current scope
public void CloseScope()
{
topScope = topScope.next; curLevel--;
}
// open a new scope and make it the current scope (topScope)
public void OpenScope()
{
Obj scop = new Obj();
scop.name = ""; scop.kind = scope; scop.constval = "";
scop.locals = null; scop.nextAdr = 0;
scop.next = topScope; topScope = scop;
curLevel++;
}
// close the current scope
public void CloseScope()
{
topScope = topScope.next; curLevel--;
}