/// <summary>
/// Evaluates this node and all of its children
/// </summary>
/// <param name="scope">The scope of this statement</param>
/// <returns></returns>
public override Statement Evaluate(Scope scope)
{
// Check if left-side expression is assignable
if (!(leftSide is AssignableExpression))
{
// Issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Left side cannot be assigned to");
return this;
}
// Evaluate both expressions
leftSide = leftSide.Evaluate(scope);
rightSide = rightSide.Evaluate(scope);
return this;
}
/// <summary>
/// Adds an agrument expression to the argument list
/// </summary>
/// <param name="expr">Argument expression</param>
public void AddArgument(Expression expr)
{
arguments.Add(expr);
}
/// <summary>
/// Evaluates this node and all its children
/// </summary>
/// <param name="scope">The scope of this expression</param>
/// <returns></returns>
public override Expression Evaluate(Scope scope)
{
// Evaluate operands
leftOperand = leftOperand.Evaluate(scope);
rightOperand = rightOperand.Evaluate(scope);
// Check if both operands are of the same type
if (leftOperand.returnType.ToCLRType() != rightOperand.returnType.ToCLRType())
{
// If not, check if left operand can be implicitely typecasted to right operand type
if (leftOperand.returnType.IsCompatible(rightOperand.returnType))
{
// Create implicit cast
CastExpression implicitCast = new CastExpression(rightOperand.returnType);
implicitCast.operand = leftOperand;
// Evaluate typecast for folding
this.leftOperand = implicitCast.Evaluate(scope);
// Set return type
this.returnType = rightOperand.returnType;
}
// If not, check if right operand can be implicitely typecasted to left operand type
else if (rightOperand.returnType.IsCompatible(leftOperand.returnType))
{
// Create implicit cast
CastExpression implicitCast = new CastExpression(leftOperand.returnType);
implicitCast.operand = rightOperand;
// Evaluate for folding
this.rightOperand = implicitCast.Evaluate(scope);
// Set return type
this.returnType = leftOperand.returnType;
}
else
{
// Types are incompatible - issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Incompatible types");
this.returnType = PrimitiveType.UNSUPPORTED;
return this;
}
}
// If operands are of the same type
else
{
// Set return type
this.returnType = leftOperand.returnType;
}
// If operand is not arithmetic, overwrite return type
if ((int)op >= 6)
{
this.returnType = PrimitiveType.BOOL;
}
// Check if operator and operands are compatible
switch (op)
{
// Addition is accepted for strings and numeric types
case BinaryOperator.Add:
// If type is not string, check if it is numerical
if (!leftOperand.returnType.Equals(PrimitiveType.STRING))
{
goto case BinaryOperator.Leq;
}
break;
// Other arithmetic operators and comparisons (except equals and not equals) are accepted for numeric types
case BinaryOperator.Sub:
case BinaryOperator.Mul:
case BinaryOperator.Div:
case BinaryOperator.Gt:
case BinaryOperator.Lt:
case BinaryOperator.Geq:
case BinaryOperator.Leq:
// Check if type is not integer or double
if (!leftOperand.returnType.Equals(PrimitiveType.INT) &&
!leftOperand.returnType.Equals(PrimitiveType.DOUBLE))
{
// Issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Arithmetic operator can only be applied to numerical types");
}
break;
// Modulo operator is accepted only for integer type
case BinaryOperator.Rem:
// Check if type is not integer
if (!leftOperand.returnType.Equals(PrimitiveType.INT))
{
// Issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Reminder operator can only be applied to integer type");
}
break;
// Equality and non equality are accepted for all types
case BinaryOperator.Eq:
case BinaryOperator.Neq:
break;
// Default case stands for logical operators
default:
// Check if type is not boolean
if (!leftOperand.returnType.Equals(PrimitiveType.BOOL))
{
// Issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Logical operator can only be applied to boolean type");
}
break;
}
// If both operands are constant expressions, perform constant folding
if ((leftOperand is ConstantExpression) && (rightOperand is ConstantExpression))
{
// Compile time evaluation of expressions is done based on type and operator
// If type is boolean
if (leftOperand.returnType.Equals(PrimitiveType.BOOL))
{
switch (op)
{
// Compute equality
case BinaryOperator.Eq:
// Cast values to bool, compare and create new constant expression
return new ConstantExpression(Primitive.Bool, (bool)(leftOperand as ConstantExpression).value ==
(bool)(rightOperand as ConstantExpression).value);
// Compute non-equality
case BinaryOperator.Neq:
// Same as exclusive or for boolean values
goto case BinaryOperator.Xor;
// Compute logical and
case BinaryOperator.And:
// Cast values to bool, apply operation and create constant expression
return new ConstantExpression(Primitive.Bool, (bool)(leftOperand as ConstantExpression).value &&
(bool)(rightOperand as ConstantExpression).value);
// Compute logical or
case BinaryOperator.Or:
// Cast values to bool, apply operation and create constant expression
return new ConstantExpression(Primitive.Bool, (bool)(leftOperand as ConstantExpression).value ||
(bool)(rightOperand as ConstantExpression).value);
// Compute logical exclusive or
case BinaryOperator.Xor:
// Cast values to bool, apply operation and create constant expression (xor is equivalent to a
// non-equality check)
return new ConstantExpression(Primitive.Bool, (bool)(leftOperand as ConstantExpression).value !=
(bool)(rightOperand as ConstantExpression).value);
}
}
// If type is double
else if (leftOperand.returnType.Equals(PrimitiveType.DOUBLE))
{
switch (op)
{
// Compute equality
case BinaryOperator.Eq:
// Cast values to double, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (double)(leftOperand as ConstantExpression).value ==
(double)(rightOperand as ConstantExpression).value);
// Compute non-equality
case BinaryOperator.Neq:
// Cast values to double, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (double)(leftOperand as ConstantExpression).value !=
(double)(rightOperand as ConstantExpression).value);
// Compute greater than
case BinaryOperator.Gt:
// Cast values to double, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (double)(leftOperand as ConstantExpression).value >
(double)(rightOperand as ConstantExpression).value);
// Compute greater than or equal to
case BinaryOperator.Geq:
// Cast values to double, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (double)(leftOperand as ConstantExpression).value >=
(double)(rightOperand as ConstantExpression).value);
// Compute less than
case BinaryOperator.Lt:
// Cast values to double, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (double)(leftOperand as ConstantExpression).value <
(double)(rightOperand as ConstantExpression).value);
// Compute less than or equal to
case BinaryOperator.Leq:
// Cast values to double, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (double)(leftOperand as ConstantExpression).value <=
(double)(rightOperand as ConstantExpression).value);
// Compute addition
case BinaryOperator.Add:
// Cast values to double, apply operation and create constant expression
return new ConstantExpression(Primitive.Double, ((double)(leftOperand as ConstantExpression).value +
(double)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
// Compute subtraction
case BinaryOperator.Sub:
// Cast values to double, apply operation and create constant expression
return new ConstantExpression(Primitive.Double, ((double)(leftOperand as ConstantExpression).value -
(double)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
// Compute multiplication
case BinaryOperator.Mul:
// Cast values to double, apply operation and create constant expression
return new ConstantExpression(Primitive.Double, ((double)(leftOperand as ConstantExpression).value *
(double)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
// Compute division
case BinaryOperator.Div:
// Cast values to double, apply operation and create constant expression
return new ConstantExpression(Primitive.Double, ((double)(leftOperand as ConstantExpression).value /
(double)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
}
}
// If type is integer
else if (leftOperand.returnType.Equals(PrimitiveType.INT))
{
switch (op)
{
// Compute equality
case BinaryOperator.Eq:
// Cast values to int, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (int)(leftOperand as ConstantExpression).value ==
(int)(rightOperand as ConstantExpression).value);
// Compute non-equality
case BinaryOperator.Neq:
// Cast values to int, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (int)(leftOperand as ConstantExpression).value !=
(int)(rightOperand as ConstantExpression).value);
// Compute greater than
case BinaryOperator.Gt:
// Cast values to int, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (int)(leftOperand as ConstantExpression).value >
(int)(rightOperand as ConstantExpression).value);
// Compute greater than or equal to
case BinaryOperator.Geq:
// Cast values to int, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (int)(leftOperand as ConstantExpression).value >=
(int)(rightOperand as ConstantExpression).value);
// Compute less than
case BinaryOperator.Lt:
// Cast values to int, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (int)(leftOperand as ConstantExpression).value <
(int)(rightOperand as ConstantExpression).value);
// Compute less than or equal to
case BinaryOperator.Leq:
// Cast values to int, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (int)(leftOperand as ConstantExpression).value <=
(int)(rightOperand as ConstantExpression).value);
// Compute addition
case BinaryOperator.Add:
// Cast values to int, apply operation and create constant expression
return new ConstantExpression(Primitive.Int, ((int)(leftOperand as ConstantExpression).value +
(int)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
// Compute subtraction
case BinaryOperator.Sub:
// Cast values to int, apply operation and create constant expression
return new ConstantExpression(Primitive.Int, ((int)(leftOperand as ConstantExpression).value -
(int)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
// Compute multiplication
case BinaryOperator.Mul:
// Cast values to int, apply operation and create constant expression
return new ConstantExpression(Primitive.Int, ((int)(leftOperand as ConstantExpression).value *
(int)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
// Compute division
case BinaryOperator.Div:
// Cast values to int, apply operation and create constant expression
return new ConstantExpression(Primitive.Int, ((int)(leftOperand as ConstantExpression).value /
(int)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
// Compute modulo
case BinaryOperator.Rem:
// Cast values to int, apply operation and create constant expression
return new ConstantExpression(Primitive.Int, ((int)(leftOperand as ConstantExpression).value %
(int)(rightOperand as ConstantExpression).value).ToString(NumberFormatInfo.InvariantInfo));
}
}
// If type is string
else if (leftOperand.returnType.Equals(PrimitiveType.STRING))
{
switch (op)
{
// Compute equality
case BinaryOperator.Eq:
// Convert values to string, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (leftOperand as ConstantExpression).value.ToString() ==
(rightOperand as ConstantExpression).value.ToString());
// Compute non-equality
case BinaryOperator.Neq:
// Convert values to string, apply operation and create constant (boolean) expression
return new ConstantExpression(Primitive.Bool, (leftOperand as ConstantExpression).value.ToString() !=
(rightOperand as ConstantExpression).value.ToString());
// Compute addition
case BinaryOperator.Add:
// Convert values to string, apply operation and create constant expression
return new ConstantExpression(Primitive.String, (leftOperand as ConstantExpression).value.ToString() +
(rightOperand as ConstantExpression).value.ToString());
}
}
}
return this;
}
/// <summary>
/// Evaluates this node and all of its children
/// </summary>
/// <param name="scope">The scope of this statement</param>
/// <returns></returns>
public override Statement Evaluate(Scope scope)
{
// Evaluate condition expression
condition = condition.Evaluate(scope);
// Evaluate repetitive statement
body = body.Evaluate(scope);
// Perform dead code elimination if the value of the condition can be evaluated at compile time
if (condition is ConstantExpression)
{
// If it is always false, replace the statement with the inner repetitive statement
if (!(condition as ConstantExpression).IsTrue())
return body;
}
// Propagate return state - if inner statement returns, no code following this statement
// will be reached
returns = body.returns;
return this;
}
void MulExpr(out Expression expr, Expression leftOperand)
{
expr = leftOperand;
while (la.kind == 47 || la.kind == 50 || la.kind == 51) {
expr = new BinaryExpression(leftOperand);
if (la.kind == 47) {
Get();
(expr as BinaryExpression).op = BinaryOperator.Mul;
} else if (la.kind == 50) {
Get();
(expr as BinaryExpression).op = BinaryOperator.Div;
} else {
Get();
(expr as BinaryExpression).op = BinaryOperator.Rem;
}
expr.t = t;
UnaryExpr(out (expr as BinaryExpression).rightOperand);
}
}
void Expression(out Expression expr)
{
expr = null;
UnaryExpr(out expr);
Expression leftOperand = expr;
EqExpr(out expr, leftOperand);
}
void ConstantExpression(out Expression expr)
{
expr = null;
if (la.kind == 4) {
Get();
expr = new ConstantExpression(CSR.AST.Primitive.String, t);
} else if (la.kind == 2) {
Get();
expr = new ConstantExpression(CSR.AST.Primitive.Int, t);
} else if (la.kind == 3) {
Get();
expr = new ConstantExpression(CSR.AST.Primitive.Double, t);
} else if (la.kind == 27) {
Get();
expr = new ConstantExpression(CSR.AST.Primitive.Bool, t);
} else if (la.kind == 26) {
Get();
expr = new ConstantExpression(CSR.AST.Primitive.Bool, t);
} else SynErr(57);
}
/// <summary>
/// Creates a new BinaryExpression given a left operand
/// </summary>
/// <param name="leftOperand"></param>
public BinaryExpression(Expression leftOperand)
{
this.leftOperand = leftOperand;
}
/// <summary>
/// Creates a new IndexerExpression given an array reference
/// </summary>
/// <param name="expr">Variable reference expression</param>
public IndexerExpression(Expression expr)
{
// Initialize members
operand = expr;
t = expr.t;
indexers = new List<Expression>();
}
/// <summary>
/// Evaluates this node and all of its children
/// </summary>
/// <param name="scope">The scope of this statement</param>
/// <returns></returns>
public override Statement Evaluate(Scope scope)
{
// Evaluate condition
condition = condition.Evaluate(scope);
// Evaluate repetitive statement
body = body.Evaluate(scope);
// Perform dead code elimination if the value of the condition can be evaluated at compile time
if (condition is ConstantExpression)
{
// If condition is always false, drop statement
if (!(condition as ConstantExpression).IsTrue())
return null;
}
return this;
}
/// <summary>
/// Evaluates this node and all of its children
/// </summary>
/// <param name="scope">The scope of this statement</param>
/// <returns></returns>
public override Statement Evaluate(Scope scope)
{
LocalScope localScope = scope as LocalScope;
// If expr is not null, we must match return value with function return type
if (expr != null)
{
// Evaluate inner expression
expr.Evaluate(scope);
// If return type is different than function return type
if (!expr.returnType.Equals(localScope.returnType))
{
// Check if an implicit typecast exists
if (expr.returnType.IsCompatible(localScope.returnType))
{
// Create typecast
CastExpression newExpr = new CastExpression(localScope.returnType);
newExpr.operand = expr;
this.expr = newExpr;
}
else
{
// Issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "invalid return type");
}
}
}
else
{
// If function returns void but we provide a different type
if (localScope.returnType.ToCLRType() != Type.GetType("System.Void"))
{
// Issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "function should return " + localScope.returnType);
}
}
return this;
}
/// <summary>
/// Evaluates this node and all of its children
/// </summary>
/// <param name="scope">The scope of this statement</param>
/// <returns></returns>
public override Statement Evaluate(Scope scope)
{
// Evaluate the condition
condition = condition.Evaluate(scope);
// Evaluate the if branch
ifBranch = ifBranch.Evaluate(scope);
// Evaluate the else branch if it exists
if (elseBranch != null)
{
elseBranch = elseBranch.Evaluate(scope);
// Propagate return state if both branches return
// This is the only case in which we can make sure code following the statement won't be reached
returns = ifBranch.returns && elseBranch.returns;
}
// Perform dead code elimination if the value of the condition can be evaluated at compile time
if (condition is ConstantExpression)
{
// If condition always holds, replace statement with the if branch
if ((condition as ConstantExpression).IsTrue())
return ifBranch;
else
// If an else branch exists, replace statemnt with it, if not, drop statement
if (elseBranch != null)
return elseBranch;
else
return null;
}
return this;
}
/// <summary>
/// Evaluates this node and all of its children
/// </summary>
/// <param name="scope">The scope of this statement</param>
/// <returns></returns>
public override Statement Evaluate(Scope scope)
{
if (!(variable is AssignableExpression))
{
// If variable is not assignable expression, issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Invalid variable for FOR statement");
return this;
}
// Evaluate all child nodes
variable = variable.Evaluate(scope);
initial = initial.Evaluate(scope);
final = final.Evaluate(scope);
body = body.Evaluate(scope);
return this;
}
/// <summary>
/// Creates a new AssignementExpression given a left-side expression and a right-side expression
/// </summary>
/// <param name="leftSide">Left-side expression</param>
/// <param name="rightSide">Right-side expression</param>
public AssignementStatement(Expression leftSide, Expression rightSide)
: base()
{
this.leftSide = leftSide;
this.rightSide = rightSide;
}
/// <summary> /// Emits code for an assignement given the right-side expression of the assignement /// </summary> /// <param name="ilGen">IL generator object</param> /// <param name="scope">The scope of this expression</param> /// <param name="rightSide">Right-side expression</param> public abstract void EmitAssignement(ILGenerator ilGen, Scope scope, Expression rightSide);
/// <summary>
/// Adds an indexer to the expression
/// </summary>
/// <param name="indexer">Indexer expression</param>
public void AddIndexer(Expression indexer)
{
indexers.Add(indexer);
}
/// <summary>
/// Evaluates this node and all its children
/// </summary>
/// <param name="scope">The scope of this expression</param>
/// <returns></returns>
public override Expression Evaluate(Scope scope)
{
// Evaluate operand
operand = operand.Evaluate(scope);
// If types are actually equal
if (operand.returnType.Equals(this.returnType))
{
// Issue warning
Compiler.Compiler.errors.Warning(t.line, t.col, "Typecast to the same type");
// Drop the typecast expression
return operand;
}
// If an implicit type cast exists, no need to evaluate further
if (operand.returnType.IsCompatible(this.returnType))
{
if (returnType.Equals(PrimitiveType.DOUBLE))
{
// If operand is constant, fold typecast
if (operand is ConstantExpression)
{
// Cast value to int, convert to double and create new constant expression
return new ConstantExpression(Primitive.Double, Convert.ToDouble((int)(operand as ConstantExpression).value));
}
return this;
}
}
// Only explicit typecast implemented is from Double to Int
if (operand.returnType.Equals(PrimitiveType.DOUBLE))
{
if (returnType.Equals(PrimitiveType.INT))
{
// If operand is constant, fold typecast
if (operand is ConstantExpression)
{
// Cast value to double, convert to int and create new constant expression
return new ConstantExpression(Primitive.Int, Convert.ToInt32((double)(operand as ConstantExpression).value));
}
return this;
}
}
// Execution shouldn't reach this line if cast is correct - issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Invalid typecast");
return this;
}
/// <summary>
/// Emits code for assignement
/// </summary>
/// <param name="ilGen">IL generator object</param>
/// <param name="scope">The scope of this expression</param>
/// <param name="rightSide">Right-side expression</param>
public override void EmitAssignement(ILGenerator ilGen, Scope scope, Expression rightSide)
{
// Emit code to index array
EmitIndexers(ilGen, scope);
// Emit code for right-side expression
rightSide.EmitCode(ilGen, scope);
// Call Set to store value at indexed position
ilGen.Emit(OpCodes.Call, ((ArrayType)operand.returnType).ToCLRType().GetMethod("Set"));
}
void AddExpr(out Expression expr, Expression leftOperand)
{
expr = null;
Expression rightOperand;
MulExpr(out expr, leftOperand);
while (la.kind == 40 || la.kind == 42) {
expr = new BinaryExpression(expr);
if (la.kind == 42) {
Get();
(expr as BinaryExpression).op = BinaryOperator.Add;
} else {
Get();
(expr as BinaryExpression).op = BinaryOperator.Sub;
}
expr.t = t;
UnaryExpr(out rightOperand);
MulExpr(out (expr as BinaryExpression).rightOperand, rightOperand);
}
}
/// <summary>
/// Evaluates this node and all its children
/// </summary>
/// <param name="scope">The scope of this expression</param>
/// <returns></returns>
public override Expression Evaluate(Scope scope)
{
// Iterate through indexers
for (int i = 0; i < indexers.Count; i++)
{
// Evaluate indexer
indexers[i] = indexers[i].Evaluate(scope);
// Check if indexer is of integer type
if (!indexers[i].returnType.Equals(PrimitiveType.INT))
{
// Ilegal indexer type - issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Indexers must be of integer type");
return this;
}
}
// Evaluate operand expression
operand = operand.Evaluate(scope);
if (operand is IndexerExpression)
{
Compiler.Compiler.errors.SemErr(operand.t.line, operand.t.col, "Cannot apply multiple indexers on array. Use [,] instead of [][]");
return this;
}
// Try to cast operand return type to ArrayType
ArrayType refType = operand.returnType as ArrayType;
// Check if cast was successful
if (refType == null)
{
// Indexers can only be applied to array types - issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Cannot apply indexers to non-array type");
return this;
}
// Check if the dimension of the array is equal to the number of indexers
if (refType.dimensions != indexers.Count)
{
// Cannot assign to arrays, only to values - issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Invalid number of indexers");
return this;
}
// Set return type
this.returnType = refType.type;
return this;
}
void EqExpr(out Expression expr, Expression leftOperand)
{
expr = null;
Expression rightOperand;
LogExpr(out expr, leftOperand);
while (StartOf(4)) {
expr = new BinaryExpression(expr);
switch (la.kind) {
case 33: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Eq;
break;
}
case 48: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Neq;
break;
}
case 34: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Gt;
break;
}
case 39: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Lt;
break;
}
case 35: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Geq;
break;
}
case 49: {
Get();
(expr as BinaryExpression).op = BinaryOperator.Leq;
break;
}
}
expr.t = t;
UnaryExpr(out rightOperand);
LogExpr(out (expr as BinaryExpression).rightOperand, rightOperand);
}
}
/// <summary>
/// Evaluates this node and all its children
/// </summary>
/// <param name="scope">The scope of this expression</param>
/// <returns></returns>
public override Expression Evaluate(Scope scope)
{
// Evaluate operand expression
operand = operand.Evaluate(scope);
// Save operand return type
PrimitiveType pType = (PrimitiveType)operand.returnType;
if (pType == null)
{
return null;
}
// Processing is done depending on operator
switch (op)
{
// Process unary minus
case UnaryOperator.UMinus:
// If operand is integer or double
if (pType.type == Primitive.Int || pType.type == Primitive.Double)
{
// Set return type
this.returnType = new PrimitiveType(pType.type);
// If operand is constant perform folding
if (operand is ConstantExpression)
{
// Fold integer value
if (pType.type == Primitive.Int)
{
// Cast value to int, add unary minus and create new constant expression
return new ConstantExpression(Primitive.Int, (-(int)(operand as ConstantExpression).value).ToString());
}
else if (pType.type == Primitive.Double)
{
// Cast value to double, add unary minus and create new constant expression
return new ConstantExpression(Primitive.Double, (-(double)(operand as ConstantExpression).value).ToString());
}
}
}
else
{
// Unary minus cannot be applied on other types
this.returnType = PrimitiveType.UNSUPPORTED;
// Issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Can only apply '-' to numeric types");
return this;
}
break;
// Process logical negation
case UnaryOperator.Not:
// If operand is boolean
if (pType.type == Primitive.Bool)
{
// Set return type
this.returnType = new PrimitiveType(pType.type);
// If oprand is constant perform folding
if (operand is ConstantExpression)
{
// Cast value to bool, negate and create new constant expression
return new ConstantExpression(Primitive.Bool, (bool)(operand as ConstantExpression).value ? "false" : "true");
}
}
else
{
// Logical negation cannot be applied on other types
this.returnType = PrimitiveType.UNSUPPORTED;
// Issue error
Compiler.Compiler.errors.SemErr(t.line, t.col, "Can only apply '!' to boolean types");
return this;
}
break;
}
return this;
}
void LogExpr(out Expression expr, Expression leftOperand)
{
expr = null;
Expression rightOperand;
AddExpr(out expr, leftOperand);
while (la.kind == 17 || la.kind == 18 || la.kind == 19) {
expr = new BinaryExpression(expr);
if (la.kind == 17) {
Get();
(expr as BinaryExpression).op = BinaryOperator.And;
} else if (la.kind == 18) {
Get();
(expr as BinaryExpression).op = BinaryOperator.Or;
} else {
Get();
(expr as BinaryExpression).op = BinaryOperator.Xor;
}
expr.t = t;
UnaryExpr(out rightOperand);
AddExpr(out (expr as BinaryExpression).rightOperand, rightOperand);
}
}
/// <summary>
/// Emits code for an assignement given the right-side expression of the assignement
/// </summary>
/// <param name="ilGen">IL generator object</param>
/// <param name="scope">The scope of this expression</param>
/// <param name="rightSide">Right-side expression</param>
public override void EmitAssignement(ILGenerator ilGen, Scope scope, Expression rightSide)
{
// Emit code for right side expression
rightSide.EmitCode(ilGen, scope);
// Use symbol table to emit variable assignement
scope.EmitVariableAssignement(name, ilGen);
}
void UnaryExpr(out Expression expr)
{
expr = null;
switch (la.kind) {
case 40: {
Get();
expr = new UnaryExpression(UnaryOperator.UMinus);
expr.t = t;
UnaryExpr(out (expr as UnaryExpression).operand);
break;
}
case 41: {
Get();
expr = new UnaryExpression(UnaryOperator.Not);
expr.t = t;
UnaryExpr(out (expr as UnaryExpression).operand);
break;
}
case 2: case 3: case 4: case 26: case 27: {
ConstantExpression(out expr);
break;
}
case 36: {
Get();
Expect(21);
expr = new CastExpression(PrimitiveType.INT);
expr.t = t;
Expect(43);
UnaryExpr(out (expr as CastExpression).operand);
break;
}
case 1: {
Get();
expr = new VariableReferenceExpression(t.val);
expr.t = t;
while (la.kind == 32) {
Get();
Expect(1);
(expr as VariableReferenceExpression).name += "." + t.val;
}
if (la.kind == 38) {
Get();
expr = new CallExpression((expr as VariableReferenceExpression).name, expr.t);
Expression argument;
if (StartOf(3)) {
Expression(out argument);
(expr as CallExpression).AddArgument(argument);
while (la.kind == 31) {
Get();
Expression(out argument);
(expr as CallExpression).AddArgument(argument);
}
}
Expect(45);
}
if (la.kind == 37) {
Get();
expr = new IndexerExpression(expr);
Expression indexer;
Expression(out indexer);
(expr as IndexerExpression).AddIndexer(indexer);
while (la.kind == 31) {
Get();
Expression(out indexer);
(expr as IndexerExpression).AddIndexer(indexer);
}
Expect(44);
}
break;
}
case 38: {
Get();
Expression(out expr);
Expect(45);
break;
}
default: SynErr(56); break;
}
}
/// <summary>
/// Creates a new CallStatement given a CallExpression
/// </summary>
/// <param name="expr">CallExpression object</param>
public CallStatement(Expression expr)
: base()
{
this.expr = expr as CallExpression;
}