private MethodDefDeclaration InjectEqualsType(TypeDefDeclaration enhancedType,
StructuralEqualityAttribute config, ICollection <FieldDefDeclaration> ignoredFields)
{
IType genericTypeInstance = enhancedType.GetCanonicalGenericInstance();
var existingMethod = enhancedType.Methods.FirstOrDefault <IMethod>(declaration =>
{
return(declaration.Name == "Equals" &&
declaration.IsPublic() &&
!declaration.IsStatic &&
declaration.ParameterCount == 1 &&
declaration.GetParameterType(0).Equals(genericTypeInstance));
});
if (existingMethod != null)
{
return(existingMethod.GetMethodDefinition());
}
// public virtual bool Equals( Typed other )
var equalsDeclaration = new MethodDefDeclaration
{
Name = "Equals",
Attributes = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual,
CallingConvention = CallingConvention.HasThis
};
enhancedType.Methods.Add(equalsDeclaration);
equalsDeclaration.Parameters.Add(new ParameterDeclaration(0, "other", genericTypeInstance));
equalsDeclaration.ReturnParameter = ParameterDeclaration.CreateReturnParameter(this.booleanType);
CompilerGeneratedAttributeHelper.AddCompilerGeneratedAttribute(equalsDeclaration);
using (var writer = InstructionWriter.GetInstance())
{
var methodBody = MethodBodyCreator.CreateModifiableMethodBody(writer, equalsDeclaration);
writer.AttachInstructionSequence(methodBody.PrincipalBlock.AddInstructionSequence());
writer.EmitInstruction(OpCodeNumber.Ldc_I4_0);
writer.EmitInstructionLocalVariable(OpCodeNumber.Stloc, methodBody.ReturnVariable);
this.InjectReferenceEquals(writer, methodBody, enhancedType);
// Writer is either attached to the same sequence (value types) or to a new one which should check the structure.
// return base.Equals(other) && this.field1 == other.field1 && ...;
if (!config.IgnoreBaseClass && enhancedType.IsValueTypeSafe() != true)
{
// Find the base method.
var baseEqualsMethod = this.instanceEqualsMethod.FindOverride(enhancedType.BaseTypeDef, true)
.GetInstance(enhancedType.Module, enhancedType.BaseType.GetGenericContext());
// Do not invoke object.Equals();
if (baseEqualsMethod.DeclaringType.GetTypeDefinition() != this.objectTypeDef)
{
writer.EmitInstruction(OpCodeNumber.Ldarg_0);
writer.EmitInstruction(OpCodeNumber.Ldarg_1);
writer.EmitInstructionMethod(OpCodeNumber.Call, baseEqualsMethod);
// base.Equals(other) returned false, go to return.
writer.EmitBranchingInstruction(OpCodeNumber.Brfalse, methodBody.ReturnSequence);
}
}
foreach (var field in GetFieldsForComparison(enhancedType, ignoredFields))
{
this.EmitEqualsField(writer, methodBody, field);
}
InjectCustomMethods(enhancedType, writer, methodBody);
// return true;
writer.EmitInstruction(OpCodeNumber.Ldc_I4_1);
writer.EmitInstructionLocalVariable(OpCodeNumber.Stloc, methodBody.ReturnVariable);
writer.EmitBranchingInstruction(OpCodeNumber.Br, methodBody.ReturnSequence);
writer.DetachInstructionSequence();
}
return(equalsDeclaration);
}