// Concatenate two literal strings
ParseNode OptimiseConcatenation(ParseNode node)
{
BinaryOpParseNode tokenNode = (BinaryOpParseNode)node;
tokenNode.Left = OptimiseExpressionTree(tokenNode.Left);
tokenNode.Right = OptimiseExpressionTree(tokenNode.Right);
if ((tokenNode.Left.ID == ParseID.STRING) && (tokenNode.Right.ID == ParseID.STRING)) {
StringParseNode op1 = (StringParseNode)tokenNode.Left;
StringParseNode op2 = (StringParseNode)tokenNode.Right;
node = new StringParseNode(op1.Value + op2.Value);
}
return node;
}
/// <summary>
/// Implements the base code generator for the node to invoke a
/// function implementation with a parse node value.
/// </summary>
/// <param name="cg">The code generator object</param>
/// <param name="node">A parse node supplied to the generator function</param>
/// <returns>The computed type</returns>
public virtual void Generate(CodeGenerator cg, ParseNode node)
{
throw new InvalidOperationException("ParseNode does not implement Generate");
}
// Block IF
ParseNode KBlockIf(ParseNode expr)
{
ConditionalParseNode node = new ConditionalParseNode();
TokenID id;
do {
ParseNode labelNode;
CollectionParseNode statements = new CollectionParseNode();
SimpleToken token = _ls.GetKeyword();
++_blockDepth;
while (!IsEndOfIfBlock(token.ID)) {
labelNode = CheckLabel();
if (labelNode != null) {
statements.Add(labelNode);
}
ParseNode subnode = Statement(token);
if (subnode != null) {
statements.Add(MarkLine());
statements.Add(subnode);
}
ExpectEndOfLine();
token = _ls.GetKeyword();
}
--_blockDepth;
// Labels on terminators are valid so we need
// to check for and add those.
labelNode = CheckLabel();
if (labelNode != null) {
statements.Add(labelNode);
}
node.Add(expr, statements);
id = token.ID;
if (id == TokenID.KELSEIF) {
ExpectToken(TokenID.LPAREN);
expr = Expression();
ExpectToken(TokenID.RPAREN);
ExpectToken(TokenID.KTHEN);
ExpectEndOfLine();
} else if (id == TokenID.KELSE) {
// We mark the end of the sequence of IF blocks with
// a null expression.
expr = null;
ExpectEndOfLine();
}
} while(id == TokenID.KELSEIF || id == TokenID.KELSE);
_ls.BackToken();
ExpectToken(TokenID.KENDIF);
return node;
}
// Given two parse nodes with types associated, this function returns the
// largest type required for a consistent arithmetic operation between them.
SymType TypePromotion(ParseNode p1, ParseNode p2)
{
return Symbol.LargestType(p1.Type, p2.Type);
}
/// <summary>
/// Emit the code to generate a call to the READ library function. A
/// parse node must be provided which evaluates to the address of the
/// identifier into which the data is read.
/// </summary>
/// <param name="cg">A CodeGenerator object</param>
/// <param name="node">A parse node for the READ identifier</param>
public override void Generate(CodeGenerator cg, ParseNode node)
{
if (cg == null) {
throw new ArgumentNullException("cg");
}
if (node is LoopParseNode) {
LoopParseNode loopNode = (LoopParseNode)node;
loopNode.Callback = this;
loopNode.Generate(cg);
} else {
Type readManagerType = typeof(JComLib.ReadManager);
List<Type> readParamTypes = new List<Type>();
cg.Emitter.LoadLocal(ReadManagerIndex);
readParamTypes.Add(readManagerType);
readParamTypes.AddRange(ReadParamsNode.Generate(cg));
if (node is IdentifierParseNode) {
IdentifierParseNode identNode = (IdentifierParseNode)node;
if (identNode.IsArrayBase) {
cg.Emitter.LoadInteger(identNode.Symbol.ArraySize);
identNode.Generate(cg);
readParamTypes.Add(typeof(int));
readParamTypes.Add(Symbol.SymTypeToSystemType(identNode.Symbol.Type).MakeArrayType());
} else if (identNode.HasSubstring) {
cg.GenerateExpression(SymType.INTEGER, identNode.SubstringStart);
if (identNode.SubstringEnd != null) {
cg.GenerateExpression(SymType.INTEGER, identNode.SubstringEnd);
} else {
cg.Emitter.LoadInteger(-1);
}
cg.LoadAddress(identNode);
readParamTypes.Add(typeof(int));
readParamTypes.Add(typeof(int));
readParamTypes.Add(Symbol.SymTypeToSystemType(identNode.Symbol.Type).MakeByRefType());
} else {
cg.LoadAddress(identNode);
readParamTypes.Add(Symbol.SymTypeToSystemType(identNode.Symbol.Type).MakeByRefType());
}
}
cg.Emitter.Call(cg.GetMethodForType(_libraryName, _name, readParamTypes.ToArray()));
cg.Emitter.StoreLocal(ReturnIndex);
if (EndLabel != null) {
cg.Emitter.LoadLocal(ReturnIndex);
cg.Emitter.LoadInteger(0);
cg.Emitter.BranchEqual((Label)EndLabel.Symbol.Info);
}
if (ErrLabel != null) {
cg.Emitter.LoadLocal(ReturnIndex);
cg.Emitter.LoadInteger(-1);
cg.Emitter.BranchEqual((Label)ErrLabel.Symbol.Info);
}
}
}
// Add this node to list of initialisation nodes that are
// executed when the method is loaded.
void AddInit(ParseNode initNode)
{
Debug.Assert(_initList != null);
_initList.Add(initNode);
}
/// <summary>
/// Emit the code to generate a call to the write library function. A
/// parse node must be specified which evaluates to the value to be
/// written.
/// </summary>
/// <param name="cg">A CodeGenerator object</param>
/// <param name="node">A parse node for the WRITE identifier</param>
public override void Generate(CodeGenerator cg, ParseNode node)
{
if (cg == null) {
throw new ArgumentNullException("cg");
}
if (node is LoopParseNode) {
LoopParseNode loopNode = (LoopParseNode)node;
loopNode.Callback = this;
loopNode.Generate(cg);
} else {
Type writeManagerType = typeof(JComLib.WriteManager);
List<Type> writeParamTypes = new List<Type>();
cg.Emitter.LoadLocal(WriteManagerIndex);
writeParamTypes.Add(writeManagerType);
if (WriteParamsNode != null) {
writeParamTypes.AddRange(WriteParamsNode.Generate(cg));
}
if (node != null) {
ParameterParseNode exprParam = new ParameterParseNode(node);
writeParamTypes.Add(exprParam.Generate(cg));
}
cg.Emitter.Call(cg.GetMethodForType(_libraryName, _name, writeParamTypes.ToArray()));
cg.Emitter.StoreLocal(ReturnIndex);
if (ErrLabel != null) {
cg.Emitter.LoadLocal(ReturnIndex);
cg.Emitter.LoadInteger(-1);
cg.Emitter.BranchEqual((Label)ErrLabel.Symbol.Info);
}
}
}
/// <summary>
/// Retrieve the label value of a SymbolParseNode.
/// </summary>
/// <param name="node">A Label parse node</param>
/// <returns>A symbol entry representing the label</returns>
public Symbol GetLabel(ParseNode node)
{
if (node == null) {
return null;
}
Debug.Assert(node is SymbolParseNode);
SymbolParseNode identNode = (SymbolParseNode)node;
return identNode.Symbol;
}
// Optimise a negation expression where both nodes are literal
// values. Substitute the node with the result of the negation.
ParseNode OptimiseMinus(ParseNode node)
{
UnaryOpParseNode tokenNode = (UnaryOpParseNode)node;
tokenNode.Operand = OptimiseExpressionTree(tokenNode.Operand);
if (tokenNode.Operand.IsNumber) {
NumberParseNode op1 = (NumberParseNode)tokenNode.Operand;
node = new NumberParseNode(-op1.Value);
}
return node;
}
// Optimise a subtraction expression where both nodes are literal
// values. Substitute the node with the result of the subtraction.
ParseNode OptimiseSubtraction(ParseNode node)
{
BinaryOpParseNode tokenNode = (BinaryOpParseNode)node;
tokenNode.Left = OptimiseExpressionTree(tokenNode.Left);
tokenNode.Right = OptimiseExpressionTree(tokenNode.Right);
if (tokenNode.IsNumber) {
NumberParseNode op1 = (NumberParseNode)tokenNode.Left;
NumberParseNode op2 = (NumberParseNode)tokenNode.Right;
node = new NumberParseNode(op1.Value - op2.Value);
}
// Check for zero simplification
if (tokenNode.Right.IsNumber) {
if (tokenNode.Right.Value.IsZero) {
return tokenNode.Left;
}
}
return node;
}
// Optimise the parse tree generated by parsing an expression in order to collapse
// arithmetic operations with constant operands.
ParseNode OptimiseExpressionTree(ParseNode node)
{
if (node != null) {
switch (node.ID) {
case ParseID.MINUS: return OptimiseMinus(node);
case ParseID.ADD: return OptimiseAddition(node);
case ParseID.MULT: return OptimiseMultiplication(node);
case ParseID.DIVIDE: return OptimiseDivision(node);
case ParseID.SUB: return OptimiseSubtraction(node);
case ParseID.EXP: return OptimiseExponentation(node);
case ParseID.CONCAT: return OptimiseConcatenation(node);
}
}
return node;
}
// Optimise an exponentation expression where both nodes are literal
// values. Substitute the node with the result of the exponentation.
ParseNode OptimiseExponentation(ParseNode node)
{
BinaryOpParseNode tokenNode = (BinaryOpParseNode)node;
tokenNode.Left = OptimiseExpressionTree(tokenNode.Left);
tokenNode.Right = OptimiseExpressionTree(tokenNode.Right);
if (tokenNode.IsNumber) {
NumberParseNode op1 = (NumberParseNode)tokenNode.Left;
NumberParseNode op2 = (NumberParseNode)tokenNode.Right;
node = new NumberParseNode(op1.Value.Pow(op2.Value));
}
// x raised to the powers of -1, 0 and 1 all yield constant expressions
// so we can simplify that right now.
if (tokenNode.Right.IsNumber) {
Variant rightValue = tokenNode.Right.Value;
if (rightValue.Compare(-1)) {
BinaryOpParseNode divNode = new BinaryOpParseNode(ParseID.DIVIDE);
divNode.Left = new NumberParseNode(new Variant(1));
divNode.Right = tokenNode.Left;
divNode.Type = tokenNode.Left.Type;
return divNode;
}
if (rightValue.IsZero) {
return new NumberParseNode(1);
}
if (rightValue.Compare(1)) {
return tokenNode.Left;
}
}
return node;
}
// Optimise a division expression where both nodes are literal
// values. Substitute the node with the result of the division.
ParseNode OptimiseDivision(ParseNode node)
{
BinaryOpParseNode tokenNode = (BinaryOpParseNode)node;
tokenNode.Left = OptimiseExpressionTree(tokenNode.Left);
tokenNode.Right = OptimiseExpressionTree(tokenNode.Right);
if (tokenNode.IsNumber) {
NumberParseNode op1 = (NumberParseNode)tokenNode.Left;
NumberParseNode op2 = (NumberParseNode)tokenNode.Right;
try {
node = new NumberParseNode(op1.Value / op2.Value);
} catch (DivideByZeroException) {
_messages.Error(MessageCode.DIVISIONBYZERO, "Constant division by zero");
}
}
return node;
}
/// <summary>
/// Adds a case statement and target label.
/// </summary>
/// <param name="expr">Case expression node</param>
/// <param name="label">Parsenode for the target label</param>
public void Add(ParseNode expr, ParseNode label)
{
_caseList.Add(expr);
_labelList.Add(label);
}
// Scan the expression tree and adjust the node type to the type
// determined by the arithmetic operation on its operators.
void AdjustNodeType(ParseNode node)
{
if (node == null) {
return;
}
switch (node.ID) {
case ParseID.IDENT: {
IdentifierParseNode identNode = (IdentifierParseNode)node;
node.Type = identNode.Symbol.Type;
break;
}
case ParseID.ADD:
case ParseID.SUB:
case ParseID.MULT:
case ParseID.EXP:
case ParseID.DIVIDE: {
BinaryOpParseNode tokenNode = (BinaryOpParseNode)node;
AdjustNodeType(tokenNode.Left);
AdjustNodeType(tokenNode.Right);
SymType type1 = tokenNode.Left.Type;
SymType type2 = tokenNode.Right.Type;
node.Type = Symbol.LargestType(type1, type2);
break;
}
}
}
/// <summary>
/// Generate code for an expression tree.
/// </summary>
/// <param name="typeNeeded">The type to which the expression should be converted if it
/// does not evaluate to that type natively.</param>
/// <param name="rootNode">The ParseNode of the root of the expression tree.</param>
/// <returns>The type of the generated expression</returns>
public SymType GenerateExpression(SymType typeNeeded, ParseNode rootNode)
{
if (rootNode == null) {
throw new ArgumentNullException("rootNode");
}
SymType thisType = rootNode.Generate(this, SymType.GENERIC);
return _em.ConvertType(thisType, typeNeeded);
}
/// <summary>
/// Adds the given parameter to this set of parameters.
/// </summary>
/// <param name="node">The Parsenode to add</param>
public void Add(ParseNode node)
{
if (node == null) {
throw new ArgumentNullException("node");
}
Add(node, false);
}
/// <summary>
/// Adds the given parsenode as a child of this token node.
/// </summary>
/// <param name="node">The Parsenode to add</param>
public void Add(ParseNode node)
{
Nodes.Add(node);
}
/// <summary>
/// Adds the given parameter to this set of parameters and specify how the
/// parameter should be passed to the function.
/// </summary>
/// <param name="node">The Parsenode to add</param>
/// <param name="useByRef">Whether the parameter should be passed by value or reference</param>
public void Add(ParseNode node, bool useByRef)
{
if (node == null) {
throw new ArgumentNullException("node");
}
ParameterParseNode paramNode = new ParameterParseNode(node);
paramNode.Type = node.Type;
paramNode.IsByRef = useByRef;
Nodes.Add(paramNode);
}
/// <summary>
/// Adds a conditional and body.
/// </summary>
/// <param name="expr">Conditional expression node</param>
/// <param name="body">Statements to be executed</param>
public void Add(ParseNode expr, CollectionParseNode body)
{
_exprList.Add(expr);
_bodyList.Add(body);
}
/// <summary>
/// Adds the given parameter to this set of parameters.
/// </summary>
/// <param name="node">The Parsenode to add</param>
/// <param name="symbol">The symbol associated with the parameter</param>
public void Add(ParseNode node, Symbol symbol)
{
if (node == null) {
throw new ArgumentNullException("node");
}
ParameterParseNode paramNode = new ParameterParseNode(node, symbol);
paramNode.Type = node.Type;
Nodes.Add(paramNode);
}
// Arithmetic IF
ParseNode KArithmeticIf(ParseNode expr)
{
ArithmeticConditionalParseNode node = new ArithmeticConditionalParseNode();
node.ValueExpression = expr;
node.Add(ParseLabel());
ExpectToken(TokenID.COMMA);
node.Add(ParseLabel());
ExpectToken(TokenID.COMMA);
node.Add(ParseLabel());
return node;
}
/// <summary>
/// Creates a subroutine or function parameters parse node.
/// </summary>
/// <param name="paramNode">A ParseNode object that contains the parameter value</param>
public ParameterParseNode(ParseNode paramNode)
{
_paramNode = paramNode;
}
// Logical IF
ParseNode KLogicalIf(ParseNode expr)
{
ConditionalParseNode node = new ConditionalParseNode();
_parsingIf = true;
CollectionParseNode body = new CollectionParseNode();
body.Add(Statement(_ls.GetKeyword()));
_parsingIf = false;
node.Add(expr, body);
return node;
}
/// <summary>
/// Creates a subroutine or function parameters parse node using the
/// given symbol as the parameter type.
/// </summary>
/// <param name="paramNode">A ParseNode object that contains the parameter value</param>
/// <param name="symbol">A Symbol table item that represents the parameter name</param>
public ParameterParseNode(ParseNode paramNode, Symbol symbol)
{
_paramNode = paramNode;
_symbol = symbol;
}
/// <summary>
/// Generate and return an XmlDocument that represents the
/// parse tree from the given root node down.
/// </summary>
/// <param name="rootNode">Parse tree root node</param>
/// <returns>The XmlDocument for the root node</returns>
public static XmlDocument Tree(ParseNode rootNode)
{
XmlDocument doc = new XmlDocument();
XmlNode docNode = doc.CreateXmlDeclaration("1.0", "UTF-8", null);
doc.AppendChild(docNode);
rootNode.Dump(new ParseNodeXML(doc, "Root"));
return doc;
}
// Return whether the node is a possible complex part
bool IsComplexPart(ParseNode node)
{
return node.ID == ParseID.NUMBER && (node.Type == SymType.INTEGER || node.Type == SymType.FLOAT);
}
