// Semantic resolution.
// This is where we check for Set-Property transformations (where an
// assignment gets changed into a methodcall)
protected override Exp ResolveExpAsRight(ISemanticResolver s)
{
// Resolve the leftside of the operator
Exp.ResolveExpAsLeft(ref m_oeLeft, s);
// Event transform actually occurs in the assignment node.
// A.e = A.e + d --> A.add_e(d)
// We have to do this before we resolve the RHS of the operator (Since we
// can't resolve events as a RHS).
if (m_oeLeft is EventExp)
{
EventExp nodeEvent = (EventExp)m_oeLeft;
EventExpEntry e = nodeEvent.Symbol;
// Here we just do some asserts.
BinaryExp b = this.m_expRight as BinaryExp;
Debug.Assert(b != null, "bad formed event +=,-=");
// By now, we know we have something of the form A = B + C
// Make sure that A=B. Since we resolved A as left, must resolve B as left too.
Exp eTempLeft = b.Left;
Exp.ResolveExpAsLeft(ref eTempLeft, s);
Debug.Assert(eTempLeft is EventExp);
Debug.Assert(Object.ReferenceEquals(((EventExp) eTempLeft).Symbol, e)); // symbols should be exact references
// Resolve C (the delegate that we're adding to the event)
Exp eTempRight = b.Right;
Exp.ResolveExpAsRight(ref eTempRight, s);
Debug.Assert(AST.DelegateDecl.IsDelegate(eTempRight.CLRType), "Event only ops w/ delegates"); // @todo -legit/
Debug.Assert(b.Op == BinaryExp.BinaryOp.cAdd || b.Op == BinaryExp.BinaryOp.cSub);
MethodExpEntry m2 = (b.Op == BinaryExp.BinaryOp.cAdd) ? e.AddMethod : e.RemoveMethod;
Exp e2 = new MethodCallExp(
nodeEvent.InstanceExp,
m2,
new ArgExp[] {
new ArgExp(EArgFlow.cIn, eTempRight)
},
s
);
Exp.ResolveExpAsRight(ref e2, s);
return e2;
}
Exp.ResolveExpAsRight(ref m_expRight, s);
// Check for calling add_, remove on events
// a.E += X
// a.E = a.E + X (parser transforms)
// if E is a delegate, and RHS is structured like E + X
// then transform to a.add_E(X) or a.remove_E(x)
// @todo - use the EventInfo to get exact add / remove functions
if (DelegateDecl.IsDelegate(m_oeLeft.CLRType))
{
// Events can only exist on a class
AST.FieldExp f = m_oeLeft as FieldExp;
if (f == null)
goto NotAnEvent;
Exp eInstance = f.InstanceExp; // ok if static
BinaryExp rhs = m_expRight as BinaryExp;
if (rhs == null)
goto NotAnEvent;
// Check if RHS is a.E + X
if ((rhs.Left != m_oeLeft) || (rhs.Right.CLRType != rhs.Left.CLRType))
goto NotAnEvent;
string stEventName = f.Symbol.Name;
string stOpName;
if (rhs.Op == BinaryExp.BinaryOp.cAdd)
stOpName = "add_" + stEventName;
else if (rhs.Op == BinaryExp.BinaryOp.cSub)
stOpName = "remove_" + stEventName;
else
goto NotAnEvent;
// a.add_E(X);
Exp e = new MethodCallExp(
eInstance,
new Identifier(stOpName),
new ArgExp[] {
new ArgExp(EArgFlow.cIn, rhs.Right)
}
);
Exp.ResolveExpAsRight(ref e, s);
e.SetLocation(this.Location);
return e;
NotAnEvent:
;
}
// Check for set-indexer
if (m_oeLeft is ArrayAccessExp)
{
ArrayAccessExp a = m_oeLeft as ArrayAccessExp;
if (a.IsIndexer)
{
// Leftside: get_Item(idx, value);
System.Type [] alParams = new Type [] {
a.ExpIndex.CLRType,
m_expRight.CLRType
};
TypeEntry t = s.ResolveCLRTypeToBlueType(a.Left.CLRType);
MethodExpEntry m = t.LookupIndexer(a.Left.Location, s, alParams, true);
Exp e = new MethodCallExp(
a.Left,
m,
new ArgExp[] {
new ArgExp(EArgFlow.cIn, a.ExpIndex),
new ArgExp(EArgFlow.cIn, m_expRight)
},
s);
Exp.ResolveExpAsRight(ref e, s);
e.SetLocation(this.Location);
return e;
}
}
// Check for transforming properties into MethodCalls
if (m_oeLeft is PropertyExp)
{
PropertyExp p = (PropertyExp) m_oeLeft;
Exp e = new MethodCallExp(
p.InstanceExp,
p.Symbol.SymbolSet,
new ArgExp[] {
new ArgExp(EArgFlow.cIn, m_expRight)
},
s);
Exp.ResolveExpAsRight(ref e, s);
e.SetLocation(this.Location);
return e;
}
CalcCLRType(s);
// Ensure type match
s.EnsureAssignable(m_expRight, m_oeLeft.CLRType);
return this;
}
// Nothing to resolve for literal expressions
protected override Exp ResolveExpAsRight(ISemanticResolver s)
{
// Always resolve our children
ResolveExpAsRight(ref m_left, s);
ResolveExpAsRight(ref m_right, s);
// If we don't match a predefined operator, then check for overloads
if (!MatchesPredefinedOp(Op, this.Left.CLRType, this.Right.CLRType))
{
// Packagage Left & Right into parameters for a method call
ArgExp [] args = new ArgExp [2] {
new ArgExp(EArgFlow.cIn, m_left),
new ArgExp(EArgFlow.cIn, m_right)
};
// Check for delegate combination
// D operator+(D, D)
// D operator-(D, D)
if (AST.DelegateDecl.IsDelegate(m_left.CLRType))
{
if (m_left.CLRType == m_right.CLRType)
{
if (Op == BinaryOp.cAdd || Op == BinaryOp.cSub)
{
System.Type d = m_left.CLRType;
// Translates to:
// op+ --> (D) System.Delegate.Combine(left, right)
// op- --> (D) System.Delegate.Remove(left, right)
TypeEntry tDelegate = s.LookupSystemType("MulticastDelegate");
string stName = (Op == BinaryOp.cAdd) ? "Combine" : "Remove";
bool dummy;
MethodExpEntry sym = tDelegate.LookupMethod(s, new Identifier(stName),
new Type[] { d, d}, out dummy);
Exp call2 = new CastObjExp(
new ResolvedTypeSig(d, s),
new MethodCallExp(
null,sym, args, s)
);
Exp.ResolveExpAsRight(ref call2, s);
return call2;
}
}
} // end delgate op+ check
// Check for System.String.Concat().
// @todo - this should be able to compress an entire subtree, not just 2 args.
// (ie, a+b+c -> String.Concat(a,b,c);
// So we can't merge this into the SearchForOverload.
// But for now we'll be lazy...
if ((Op == BinaryOp.cAdd) && (Left.CLRType == typeof(string) || Right.CLRType == typeof(string)))
{
Exp call2 = new MethodCallExp(
new DotObjExp(
new SimpleObjExp(
new Identifier("System", this.m_filerange)
),
new Identifier("String", this.m_filerange)),
new Identifier("Concat", m_filerange),
args);
call2.SetLocation(this.Location);
Exp.ResolveExpAsRight(ref call2, s);
return call2;
}
MethodExpEntry m = SearchForOverloadedOp(s);
if (m == null && (Op == BinaryOp.cEqu || Op == BinaryOp.cNeq))
{
// If it's '==' or '!=', then it's ok if we didn't find
// an overload.
} else
{
// Couldn't find an overload, throw error
if (m == null)
{
//ThrowError_NoAcceptableOperator(s, this.Location, m_left.CLRType, m_right.CLRType, Op);
ThrowError(SymbolError.NoAcceptableOperator(this.Location, m_left.CLRType, m_right.CLRType, Op));
}
// Replace this node w/ the method call
MethodCallExp call = new MethodCallExp(null, m, args, s);
call.SetLocation(this.Location);
return call;
}
}
CalcCLRType(s);
return this;
}