/// <summary>
/// Locates the target for an expression.
/// </summary>
/// <returns>The data element.</returns>
/// <param name="network">The top-level network.</param>
/// <param name="proc">The process where the method is located.</param>
/// <param name="method">The method where the statement is found.</param>
/// <param name="statement">The statement where the expression is found.</param>
/// <param name="expression">The expression to examine.</param>
protected ASTItem TryLocateElement(NetworkState network, ProcessState proc, MethodState method, Statement statement, ICSharpCode.Decompiler.CSharp.Syntax.Expression expression)
{
if (expression is ICSharpCode.Decompiler.CSharp.Syntax.InvocationExpression)
{
var e = expression as ICSharpCode.Decompiler.CSharp.Syntax.InvocationExpression;
var target = e.Target;
return(LocateDataElement(network, proc, method, statement, target));
}
else if (expression is ICSharpCode.Decompiler.CSharp.Syntax.IndexerExpression)
{
var e = expression as ICSharpCode.Decompiler.CSharp.Syntax.IndexerExpression;
var target = e.Target;
return(LocateDataElement(network, proc, method, statement, target));
}
else if (expression is ICSharpCode.Decompiler.CSharp.Syntax.IdentifierExpression)
{
var e = expression as ICSharpCode.Decompiler.CSharp.Syntax.IdentifierExpression;
var name = e.Identifier;
Variable variable;
if (method != null && method.TryGetVariable(name, out variable))
{
return(variable);
}
if (method != null)
{
var p = method.Parameters.FirstOrDefault(x => x.Name == name);
if (p != null)
{
return(p);
}
}
if (proc.Variables.TryGetValue(name, out variable))
{
return(variable);
}
Signal signal;
if (proc != null && proc.Signals.TryGetValue(name, out signal))
{
return(signal);
}
return(null);
}
else if (expression is ICSharpCode.Decompiler.CSharp.Syntax.MemberReferenceExpression)
{
var e = expression as ICSharpCode.Decompiler.CSharp.Syntax.MemberReferenceExpression;
ASTItem current = null;
var parts = new List <string>();
ICSharpCode.Decompiler.CSharp.Syntax.Expression ec = e;
while (ec != null)
{
if (ec is ICSharpCode.Decompiler.CSharp.Syntax.MemberReferenceExpression)
{
parts.Add(((ICSharpCode.Decompiler.CSharp.Syntax.MemberReferenceExpression)ec).MemberName);
ec = ((ICSharpCode.Decompiler.CSharp.Syntax.MemberReferenceExpression)ec).Target;
}
else if (ec is ICSharpCode.Decompiler.CSharp.Syntax.ThisReferenceExpression)
{
//parts.Add("this");
ec = null;
break;
}
else if (ec is ICSharpCode.Decompiler.CSharp.Syntax.IdentifierExpression)
{
parts.Add(((ICSharpCode.Decompiler.CSharp.Syntax.IdentifierExpression)ec).Identifier);
ec = null;
break;
}
else if (ec is ICSharpCode.Decompiler.CSharp.Syntax.TypeReferenceExpression)
{
TypeDefinition dc = null;
if (method != null)
{
dc = method.SourceMethod.DeclaringType;
}
else if (proc != null)
{
dc = proc.CecilType.Resolve();
}
var ecs = ec.ToString();
if (dc != null)
{
if (ecs == dc.FullName || ecs == dc.Name)
{
ec = null;
//parts.Add("this");
break;
}
var targetproc = network.Processes.FirstOrDefault(x => x.CecilType.Name == ecs || x.CecilType.FullName == ecs);
if (targetproc != null)
{
// This is a static reference
current = null; //targetproc;
break;
}
var bt = LoadTypeByName(ecs, dc.Module);
if (bt == null)
{
bt = LoadTypeByName(dc.FullName + "." + ecs, method.SourceMethod.Module);
}
if (bt == null)
{
bt = LoadTypeByName(dc.Namespace + "." + ecs, method.SourceMethod.Module);
}
// In some cases dc.Namespace is empty ...
if (bt == null && proc != null && proc.SourceType != null)
{
bt = LoadTypeByName(proc.SourceType.Namespace + "." + ecs, method.SourceMethod.Module);
}
if (bt != null && parts.Count == 1)
{
var br = bt.Resolve();
var px = br.Fields.FirstOrDefault(x => x.Name == parts[0]);
// Enum flags are encoded as constants
if (br.IsEnum)
{
if (px == null)
{
throw new Exception($"Unable to find enum value {parts[0]} in {br.FullName}");
}
return(new Constant()
{
CecilType = bt,
DefaultValue = px,
Source = expression
});
}
else
{
// This is a constant of sorts
var pe = network.ConstantLookup.Keys.FirstOrDefault(x => x.Name == parts[0]);
if (pe != null)
{
return(network.ConstantLookup[pe]);
}
return(network.ConstantLookup[px] = new Constant()
{
CecilType = px.FieldType,
Name = parts[0],
Source = px,
Parent = network
});
}
//parts.AddRange(bt.FullName.Split('.').Reverse());
}
break;
}
// Likely a static reference, which is stored as a global constant
ec = null;
}
else
{
throw new Exception($"Unexpected element in reference chain: {ec.GetType().FullName}");
}
}
parts.Reverse();
var fullname = string.Join(".", parts);
if (parts.First() == "this")
{
parts.RemoveAt(0);
if (proc == null)
{
throw new Exception("Attempting to do a resolve of \this\" but no process context is provided");
}
current = proc;
}
var first = true;
foreach (var el in parts)
{
var isIsFirst = first;
first = false;
if (current == null)
{
var pe = network.ConstantLookup.Keys.FirstOrDefault(x => x.Name == el);
if (pe != null)
{
current = network.ConstantLookup[pe];
continue;
}
}
if (current is MethodState || (isIsFirst && current == null))
{
//if (method.LocalRenames.ContainsKey(el))
// el = method.LocalRenames[el];
var mt = current as MethodState ?? method;
if (mt != null)
{
Variable temp;
if (mt.TryGetVariable(el, out temp))
{
current = temp;
continue;
}
var p = mt.Parameters.FirstOrDefault(x => x.Name == el);
if (p != null)
{
current = p;
continue;
}
if (mt.ReturnVariable != null && !string.IsNullOrWhiteSpace(mt.ReturnVariable.Name) && el == mt.ReturnVariable.Name)
{
current = mt.ReturnVariable;
continue;
}
}
}
if (current is ProcessState || (isIsFirst && current == null))
{
var pr = current as ProcessState ?? proc;
if (pr != null)
{
if (pr.BusInstances.ContainsKey(el))
{
current = pr.BusInstances[el];
continue;
}
if (pr.Signals.ContainsKey(el))
{
current = pr.Signals[el];
continue;
}
if (pr.Variables.ContainsKey(el))
{
current = pr.Variables[el];
continue;
}
if (pr.Methods != null)
{
var p = pr.Methods.FirstOrDefault(x => x.Name == el);
if (p != null)
{
current = p;
continue;
}
}
}
}
if (current is Bus)
{
current = ((Bus)current).Signals.FirstOrDefault(x => x.Name == el);
if (current != null)
{
continue;
}
}
if (current is Variable)
{
var fi = ((Variable)current).CecilType.Resolve().Fields.FirstOrDefault(x => x.Name == el);
if (fi != null)
{
current = new Variable()
{
Name = el,
Parent = current,
Source = fi,
CecilType = fi.FieldType,
DefaultValue = null
};
continue;
}
var pi = ((Variable)current).CecilType.Resolve().Properties.FirstOrDefault(x => x.Name == el);
if (pi != null)
{
current = new Variable()
{
Name = el,
Parent = current,
Source = fi,
CecilType = fi.FieldType,
DefaultValue = null
};
continue;
}
}
if (el == "Length" && (current is DataElement) && ((DataElement)current).CecilType.IsArrayType())
{
return(new Constant()
{
ArrayLengthSource = current as DataElement,
CecilType = LoadType(typeof(int)),
DefaultValue = null,
Source = (current as DataElement).Source
});
}
throw new Exception($"Failed lookup at {el} in {fullname}");
}
if (current == null)
{
throw new Exception($"Failed to fully resolve {fullname}");
}
return(current);
}
else
{
throw new Exception($"Unable to find a data element for an expression of type {expression.GetType().FullName}");
}
}