/*
* Method assumes preprocessor came
* in and dealt with labels and directives.
*/
public bool Derive(Token[] tokens)
{
DTree curchild = null, tempchild = null;
Token curtoken;
string nmemonic = null;
string iden;
int i = 0;
next = null;
children = null;
if (tokens.Length == 0)
{
return(true);
}
curtoken = tokens[0];
if (curtoken.id != TokenKind.IDENTIFIER)
{
return(SyntaxErr());
}
iden = ((IdentifierToken)curtoken).identifier.ToUpper();
if (NmemonicTree.IsNmemonic(iden))
{
children = new NmemonicTree(iden);
curchild = children;
i = 1;
nmemonic = iden;
}
else
{
return(SyntaxErr());
}
while (i < tokens.Length)
{
curtoken = tokens[i];
switch (curtoken.id)
{
case TokenKind.IDENTIFIER:
iden = ((IdentifierToken)curtoken).identifier.ToUpper();
if (RegTree.IsReg(iden))
{
/*
* C is a register and also a condition.
* To solve this ambiguity, if the nmemonic requires
* a condition, it doesn't require a register, so create
* a new register tree iff the nmemonic is not conditional.
*/
if (NmemonicTree.IsConditionalNmemonic(nmemonic) &&
iden.Equals("C"))
{
tempchild = new ConditionTree("C");
}
else
{
tempchild = new RegTree(iden);
}
}
else if (NormPairTree.IsNormPair(iden))
{
tempchild = new NormPairTree(iden);
}
else if (SpecPairTree.IsSpecPair(iden))
{
tempchild = new SpecPairTree(iden);
}
else if (ConditionTree.IsCondition(iden))
{
tempchild = new ConditionTree(iden);
}
else if (SpecRegTree.IsSpecReg(iden))
{
tempchild = new SpecRegTree(iden);
}
else if (IRegTree.IsIReg(iden))
{
tempchild = new IRegTree(iden);
}
else if (IPairTree.IsIPair(iden))
{
tempchild = new IPairTree(iden);
}
else
{
return(SyntaxErr());
}
curchild.next = tempchild;
curchild = tempchild;
i++;
break;
case TokenKind.NUMBER:
tempchild = new ImmTree(((NumberToken)curtoken).number);
curchild.next = tempchild;
curchild = tempchild;
i++;
break;
case TokenKind.OPERATOR:
OperatorKind op = ((OperatorToken)curtoken).op;
switch (op)
{
case OperatorKind.LPAREN:
int start = i;
Token[] adrtokens;
i++;
while (i < tokens.Length)
{
curtoken = tokens[i];
if (curtoken.id == TokenKind.OPERATOR &&
((OperatorToken)curtoken).op
== OperatorKind.RPAREN)
{
break;
}
i++;
}
if (i >= tokens.Length)
{
return(SyntaxErr());
}
adrtokens = new Token[i - start - 1];
Array.Copy(tokens, start + 1,
adrtokens, 0, adrtokens.Length);
tempchild = new AdrTree();
bool success = ((AdrTree)tempchild).
FormAdrTree(adrtokens, start + 1);
if (!success)
{
return(false);
}
curchild.next = tempchild;
curchild = tempchild;
i++;
break;
case OperatorKind.PLUS:
if (i >= tokens.Length - 1)
{
return(SyntaxErr());
}
Token numtokenadd = tokens[i + 1];
if (numtokenadd.id != TokenKind.NUMBER)
{
return(SyntaxErr());
}
tempchild = new ImmTree(((NumberToken)numtokenadd).number);
curchild.next = tempchild;
curchild = tempchild;
i += 2;
break;
case OperatorKind.MINUS:
if (i >= tokens.Length - 1)
{
return(SyntaxErr());
}
Token numtokensub = tokens[i + 1];
if (numtokensub.id != TokenKind.NUMBER)
{
return(SyntaxErr());
}
tempchild = new ImmTree(-((NumberToken)numtokensub).number);
curchild.next = tempchild;
curchild = tempchild;
i += 2;
break;
default:
return(SyntaxErr());
}
break;
default:
break;
}
if (i < tokens.Length)
{
curtoken = tokens[i];
if (curtoken.id != TokenKind.OPERATOR ||
((OperatorToken)curtoken).op != OperatorKind.COMMA)
{
return(SyntaxErr());
}
i++;
if (i >= tokens.Length)
{
return(SyntaxErr());
}
}
}
return(true);
}
public bool FormAdrTree(Token[] adrtokens, int startindex)
{
kind = DTKind.ADR;
Token curtoken;
DTree currchild, tempchild;
if (adrtokens.Length <= 0)
{
Console.Error.WriteLine("ERROR in AdrTree()");
Console.Error.WriteLine("Tokens array is empty");
Environment.Exit(-1);
}
curtoken = adrtokens[0];
if (curtoken.id == TokenKind.IDENTIFIER)
{
string iden = ((IdentifierToken)curtoken).identifier.ToUpper();
if (NormPairTree.IsNormPair(iden))
{
this.children = new NormPairTree(iden);
}
else if (IPairTree.IsIPair(iden))
{
this.children = new IPairTree(iden);
}
else if (RegTree.IsReg(iden))
{
this.children = new RegTree(iden);
}
else
{
return(SyntaxErr());
}
currchild = this.children;
if (adrtokens.Length == 3 && currchild.kind == DTKind.IPAIR)
{
curtoken = adrtokens[1];
Token numbertoken = adrtokens[2];
if (curtoken.id == TokenKind.OPERATOR &&
numbertoken.id == TokenKind.NUMBER)
{
OperatorKind op = ((OperatorToken)curtoken).op;
int number = ((NumberToken)numbertoken).number;
if (op != OperatorKind.PLUS && op != OperatorKind.MINUS)
{
return(SyntaxErr());
}
tempchild = new OperatorTree(op);
currchild.next = tempchild;
currchild = tempchild;
tempchild = new ImmTree(number);
currchild.next = tempchild;
currchild = tempchild;
}
}
else if (adrtokens.Length != 1)
{
return(SyntaxErr());
}
return(true);
}
else if (curtoken.id == TokenKind.NUMBER)
{
this.children = new ImmTree(((NumberToken)curtoken).number);
if (adrtokens.Length != 1)
{
return(SyntaxErr());
}
}
else
{
return(SyntaxErr());
}
return(true);
}