private static void ProcessClass(TypeDefinition classDefinition, SystemReferences systemReferences, ILogger logger, IDictionary <MethodDefinition, MethodDefinition> weavedMethods)
{
foreach (var property in classDefinition.Properties)
{
ProcessProperty(property, systemReferences, logger, weavedMethods);
}
}
private static void ProcessProperty(PropertyDefinition property, SystemReferences systemReferences, ILogger logger, IDictionary <MethodDefinition, MethodDefinition> weavedMethods)
{
if (!ConsumeLazyAttribute(property, out var threadingMode))
{
return;
}
if (property.HasParameters)
{
throw new WeavingException($"Unsupported property {property} => property has parameters");
}
if (property.SetMethod != null)
{
throw new WeavingException($"Unsupported property {property} => property has setter");
}
var originalMethod = property.GetMethod;
if (originalMethod == null || !originalMethod.HasBody)
{
throw new WeavingException($"Unsupported property {property} => property has no getter");
}
var isStatic = originalMethod.IsStatic;
var classDefinition = originalMethod.DeclaringType;
logger.LogInfo($"Weave Lazy into {property.FullName}");
var propertyType = property.PropertyType;
var lazyTypeReference = systemReferences.LazyTypeReference;
var funcTypeReference = systemReferences.FuncTypeReference;
var genericLazyTypeInstance = lazyTypeReference.MakeGenericInstanceType(propertyType);
var genericFuncTypeInstance = funcTypeReference.MakeGenericInstanceType(propertyType);
var lazyFieldName = $"<{property.Name}>_Lazy_Fody_BackingField";
var lazyMethodName = $"<{property.Name}>_Lazy_Fody_Method";
// replace the property getter with a new method: { return _Lazy_Fody_BackingField.Value }
// -- create field of type: System.Lazy<property type>
var lazyField = new FieldDefinition(lazyFieldName, FieldAttributes.Private, genericLazyTypeInstance);
if (isStatic)
{
lazyField.IsStatic = true;
}
classDefinition.Fields.Add(lazyField);
// -- create
var originalMethodName = originalMethod.Name;
var wrapperMethod = new MethodDefinition(originalMethodName, originalMethod.Attributes, originalMethod.ReturnType);
var lazyValueGetter = systemReferences.LazyValueGetterReference.OnGenericType(genericLazyTypeInstance);
var wrapperMethodInstructions = wrapperMethod.Body.Instructions;
// -- rename old method
originalMethod.IsSpecialName = false;
originalMethod.Name = lazyMethodName;
MethodReference originalMethodReference = originalMethod;
FieldReference lazyFieldReference = lazyField;
if (classDefinition.HasGenericParameters)
{
var classReference = classDefinition.MakeGenericInstanceType(classDefinition.GenericParameters.OfType <TypeReference>().ToArray());
originalMethodReference = originalMethod.OnGenericType(classReference);
lazyFieldReference = new FieldReference(lazyField.Name, lazyField.FieldType, classReference);
}
if (isStatic)
{
wrapperMethodInstructions.AddRange(
Instruction.Create(OpCodes.Ldsfld, lazyFieldReference),
Instruction.Create(OpCodes.Call, lazyValueGetter),
Instruction.Create(OpCodes.Ret));
}
else
{
wrapperMethodInstructions.AddRange(
Instruction.Create(OpCodes.Ldarg_0),
Instruction.Create(OpCodes.Ldfld, lazyFieldReference),
Instruction.Create(OpCodes.Callvirt, lazyValueGetter),
Instruction.Create(OpCodes.Ret)
);
}
// -- add new wrapper method
property.GetMethod = wrapperMethod;
classDefinition.Methods.Add(wrapperMethod);
// -- inject initialization of lazy field into constructor(s)
var funcConstructor = systemReferences.FuncConstructorReference.OnGenericType(genericFuncTypeInstance);
var lazyConstructor = systemReferences.LazyConstructorReference.OnGenericType(genericLazyTypeInstance);
if (isStatic)
{
classDefinition.InsertIntoStaticConstructor(
Instruction.Create(OpCodes.Ldnull),
Instruction.Create(OpCodes.Ldftn, originalMethodReference),
Instruction.Create(OpCodes.Newobj, funcConstructor),
Instruction.Create(OpCodes.Ldc_I4, threadingMode),
Instruction.Create(OpCodes.Newobj, lazyConstructor),
Instruction.Create(OpCodes.Stsfld, lazyFieldReference));
}
else
{
classDefinition.InsertIntoConstructors(() => new[] {
Instruction.Create(OpCodes.Ldarg_0),
Instruction.Create(OpCodes.Ldarg_0),
Instruction.Create(OpCodes.Ldftn, originalMethodReference),
Instruction.Create(OpCodes.Newobj, funcConstructor),
Instruction.Create(OpCodes.Ldc_I4, threadingMode),
Instruction.Create(OpCodes.Newobj, lazyConstructor),
Instruction.Create(OpCodes.Stfld, lazyFieldReference)
});
}
weavedMethods[originalMethod] = wrapperMethod;
}
internal static void Process(this ModuleDefinition moduleDefinition, ILogger logger, SystemReferences coreReferences)
{
var allTypes = moduleDefinition.GetTypes();
var allClasses = allTypes
.Where(x => x.IsClass && (x.BaseType != null))
.ToArray();
var weavedMethods = new Dictionary <MethodDefinition, MethodDefinition>();
foreach (var classDefinition in allClasses)
{
ProcessClass(classDefinition, coreReferences, logger, weavedMethods);
}
var injectedMethods = new HashSet <MethodDefinition>(weavedMethods.Values);
foreach (var classDefinition in allClasses)
{
PostProcessClass(classDefinition, logger, weavedMethods, injectedMethods);
}
}