/// <summary>
/// If there is an anonymous delegate within a postcondition, then there
/// will be a call to a delegate constructor.
/// That call looks like "d..ctor(o,m)" where d is the type of the delegate.
/// There are two cases depending on whether the anonymous delegate captured
/// anything. In both cases, m is the method implementing the anonymous delegate.
/// (1) It does capture something. Then o is the instance of the closure class
/// implementing the delegate, and m is an instance method in the closure
/// class.
/// (2) It does *not* capture anything. Then o is the literal for null and
/// m is a static method that was added directly to the class.
///
/// This method will cause the method (i.e., m) to be visited to collect any
/// Result<T>() expressions that occur in it.
/// </summary>
/// <param name="cons">The AST representing the call to the constructor
/// of the delegate type.</param>
/// <returns>Whatever the base visitor returns</returns>
public override Expression VisitConstruct(Construct cons)
{
if (cons.Type is DelegateNode)
{
UnaryExpression ue = cons.Operands[1] as UnaryExpression;
if (ue == null)
{
goto JustVisit;
}
MemberBinding mb = ue.Operand as MemberBinding;
if (mb == null)
{
goto JustVisit;
}
Method m = mb.BoundMember as Method;
if (!HelperMethods.IsCompilerGenerated(m))
{
goto JustVisit;
}
Contract.Assume(m != null);
m = Definition(m);
this.delegateNestingLevel++;
TypeNode savedClosureClass = this.currentClosureClassInstance;
Method savedClosureMethod = this.currentClosureMethod;
Expression savedCurrentAccessToTopLevelClosure = this.currentAccessToTopLevelClosure;
try
{
this.currentClosureMethod = m;
if (m.IsStatic)
{
this.currentClosureClassInstance = null; // no closure object
}
else
{
this.currentClosureClassInstance = cons.Operands[0].Type;
if (savedClosureClass == null)
{
// Then this is the top-level closure class.
this.topLevelClosureClassInstance = this.currentClosureClassInstance;
this.topLevelClosureClassDefinition = Definition(this.topLevelClosureClassInstance);
this.currentAccessToTopLevelClosure = new This(this.topLevelClosureClassDefinition);
this.properlyInstantiatedFieldType = this.originalLocalForResult.Type;
if (this.topLevelMethodFormals != null)
{
Contract.Assume(this.topLevelClosureClassDefinition.IsGeneric);
Contract.Assume(topLevelClosureClassDefinition.TemplateParameters.Count >=
this.topLevelMethodFormals.Count);
// replace method type parameters in result properly with last n corresponding type parameters of closure class
TypeNodeList closureFormals = topLevelClosureClassDefinition.TemplateParameters;
if (closureFormals.Count > this.topLevelMethodFormals.Count)
{
int offset = closureFormals.Count - this.topLevelMethodFormals.Count;
closureFormals = new TypeNodeList(this.topLevelMethodFormals.Count);
for (int i = 0; i < this.topLevelMethodFormals.Count; i++)
{
closureFormals.Add(topLevelClosureClassDefinition.TemplateParameters[i + offset]);
}
}
Duplicator dup = new Duplicator(this.declaringType.DeclaringModule, this.declaringType);
Specializer spec = new Specializer(this.declaringType.DeclaringModule,
topLevelMethodFormals, closureFormals);
var type = dup.VisitTypeReference(this.originalLocalForResult.Type);
type = spec.VisitTypeReference(type);
this.properlyInstantiatedFieldType = type;
}
}
else
{
while (currentClosureClassInstance.Template != null)
{
currentClosureClassInstance = currentClosureClassInstance.Template;
}
// Find the field in this.closureClass that the C# compiler generated
// to point to the top-level closure
foreach (Member mem in this.currentClosureClassInstance.Members)
{
Field f = mem as Field;
if (f == null)
{
continue;
}
if (f.Type == this.topLevelClosureClassDefinition)
{
var consolidatedTemplateParams = this.currentClosureClassInstance.ConsolidatedTemplateParameters;
TypeNode thisType;
if (consolidatedTemplateParams != null && consolidatedTemplateParams.Count > 0)
{
thisType =
this.currentClosureClassInstance.GetGenericTemplateInstance(
this.assemblyBeingRewritten, consolidatedTemplateParams);
}
else
{
thisType = this.currentClosureClassInstance;
}
this.currentAccessToTopLevelClosure = new MemberBinding(new This(thisType), f);
break;
}
}
}
}
this.VisitBlock(m.Body);
}
finally
{
this.delegateNestingLevel--;
this.currentClosureMethod = savedClosureMethod;
this.currentClosureClassInstance = savedClosureClass;
this.currentAccessToTopLevelClosure = savedCurrentAccessToTopLevelClosure;
}
}
JustVisit:
return(base.VisitConstruct(cons));
}