/*********
** Private methods
*********/
/// <summary>Rewrite a loaded type definition.</summary>
/// <param name="type">The type definition to rewrite.</param>
/// <returns>Returns whether the type was modified.</returns>
private bool RewriteTypeDefinition(TypeDefinition type)
{
bool changed = false;
changed |= this.RewriteCustomAttributes(type.CustomAttributes);
changed |= this.RewriteGenericParameters(type.GenericParameters);
foreach (InterfaceImplementation @interface in type.Interfaces)
{
changed |= this.RewriteTypeReference(@interface.InterfaceType, newType => @interface.InterfaceType = newType);
}
if (type.BaseType.FullName != "System.Object")
{
changed |= this.RewriteTypeReference(type.BaseType, newType => type.BaseType = newType);
}
foreach (MethodDefinition method in type.Methods)
{
changed |= this.RewriteTypeReference(method.ReturnType, newType => method.ReturnType = newType);
changed |= this.RewriteGenericParameters(method.GenericParameters);
changed |= this.RewriteCustomAttributes(method.CustomAttributes);
foreach (ParameterDefinition parameter in method.Parameters)
{
changed |= this.RewriteTypeReference(parameter.ParameterType, newType => parameter.ParameterType = newType);
}
foreach (var methodOverride in method.Overrides)
{
changed |= this.RewriteMethodReference(methodOverride);
}
if (method.HasBody)
{
foreach (VariableDefinition variable in method.Body.Variables)
{
changed |= this.RewriteTypeReference(variable.VariableType, newType => variable.VariableType = newType);
}
// rewrite CIL instructions
ILProcessor cil = method.Body.GetILProcessor();
Collection <Instruction> instructions = cil.Body.Instructions;
bool addedInstructions = false;
for (int i = 0; i < instructions.Count; i++)
{
var instruction = instructions[i];
if (instruction.OpCode.Code == Code.Nop)
{
continue;
}
int oldCount = cil.Body.Instructions.Count;
changed |= this.RewriteInstruction(instruction, cil, newInstruction =>
{
changed = true;
cil.Replace(instruction, newInstruction);
instruction = newInstruction;
});
if (cil.Body.Instructions.Count > oldCount)
{
addedInstructions = true;
}
}
// special case: added instructions may cause an instruction to be out of range
// of a short jump that references it
if (addedInstructions)
{
foreach (var instruction in instructions)
{
var longJumpCode = RewriteHelper.GetEquivalentLongJumpCode(instruction.OpCode);
if (longJumpCode != null)
{
instruction.OpCode = longJumpCode.Value;
}
}
changed = true;
}
}
}
return(changed);
}
/// <summary>Get whether a type has a method whose signature matches the one expected by a method reference.</summary>
/// <param name="type">The type to check.</param>
/// <param name="reference">The method reference.</param>
public static bool HasMatchingSignature(Type type, MethodReference reference)
{
return(type
.GetMethods(BindingFlags.Instance | BindingFlags.Static | BindingFlags.DeclaredOnly | BindingFlags.Public)
.Any(method => RewriteHelper.HasMatchingSignature(method, reference)));
}
/// <summary>Get whether the field is a reference to the expected type and field.</summary>
/// <param name="instruction">The IL instruction.</param>
/// <param name="fullTypeName">The full type name containing the expected field.</param>
/// <param name="fieldName">The name of the expected field.</param>
public static bool IsFieldReferenceTo(Instruction instruction, string fullTypeName, string fieldName)
{
FieldReference fieldRef = RewriteHelper.AsFieldReference(instruction);
return(RewriteHelper.IsFieldReferenceTo(fieldRef, fullTypeName, fieldName));
}
/// <summary>Rewrite custom attributes if needed.</summary>
/// <param name="attributes">The current custom attributes.</param>
private bool RewriteCustomAttributes(Collection <CustomAttribute> attributes)
{
bool rewritten = false;
for (int attrIndex = 0; attrIndex < attributes.Count; attrIndex++)
{
CustomAttribute attribute = attributes[attrIndex];
bool curChanged = false;
// attribute type
TypeReference newAttrType = null;
rewritten |= this.RewriteTypeReference(attribute.AttributeType, newType =>
{
newAttrType = newType;
curChanged = true;
});
// constructor arguments
TypeReference[] argTypes = new TypeReference[attribute.ConstructorArguments.Count];
for (int i = 0; i < argTypes.Length; i++)
{
var arg = attribute.ConstructorArguments[i];
argTypes[i] = arg.Type;
rewritten |= this.RewriteTypeReference(arg.Type, newType =>
{
argTypes[i] = newType;
curChanged = true;
});
}
// swap attribute
if (curChanged)
{
// get constructor
MethodDefinition constructor = (newAttrType ?? attribute.AttributeType)
.Resolve()
.Methods
.Where(method => method.IsConstructor)
.FirstOrDefault(ctor => RewriteHelper.HasMatchingSignature(ctor, attribute.Constructor));
if (constructor == null)
{
throw new InvalidOperationException($"Can't rewrite attribute type '{attribute.AttributeType.FullName}' to '{newAttrType?.FullName}', no equivalent constructor found.");
}
// create new attribute
var newAttr = new CustomAttribute(this.Module.ImportReference(constructor));
for (int i = 0; i < argTypes.Length; i++)
{
newAttr.ConstructorArguments.Add(new CustomAttributeArgument(argTypes[i], attribute.ConstructorArguments[i].Value));
}
foreach (var prop in attribute.Properties)
{
newAttr.Properties.Add(new CustomAttributeNamedArgument(prop.Name, prop.Argument));
}
foreach (var field in attribute.Fields)
{
newAttr.Fields.Add(new CustomAttributeNamedArgument(field.Name, field.Argument));
}
// swap attribute
attributes[attrIndex] = newAttr;
rewritten = true;
}
}
return(rewritten);
}
