/// <summary>
/// Create a pe class-library representation of a <see cref="EnumDefinition"/>.
/// </summary>
/// <exception cref="Exceptions.InvalidAssemblyNameException">
/// Thrown when a invalid assembly name is given.
/// </exception>
/// <exception cref="Exceptions.InvalidNamespaceException">
/// Thrown when a invalid namespace identifier is given.
/// </exception>
/// <exception cref="Exceptions.OutOfBoundsValueException">
/// Thrown when enum value does not fit in given storage-type.
/// </exception>
/// <param name="enumDefinition">Enum to generate a class-library for</param>
/// <param name="assemblyName">Name of the assembly to generate</param>
/// <param name="namespace">Optional namespace to add the enum to</param>
/// <param name="storageType">Underlying enum storage-type to use</param>
/// <returns>Binary pe file containing the generated class-library</returns>
public static byte[] ExportClassLibrary(
this EnumDefinition enumDefinition,
string assemblyName,
string @namespace = null,
StorageType storageType = StorageType.Implicit)
{
if (enumDefinition == null)
{
throw new ArgumentNullException(nameof(enumDefinition));
}
if (string.IsNullOrEmpty(assemblyName) || !IdentifierValidator.Validate(assemblyName))
{
throw new InvalidAssemblyNameException(assemblyName);
}
if (!string.IsNullOrEmpty(@namespace) && !IdentifierValidator.ValidateNamespace(@namespace))
{
throw new InvalidNamespaceException(@namespace);
}
foreach (var oobEntry in enumDefinition.Entries.Where(e => !storageType.Validate(e.Value)))
{
throw new OutOfBoundsValueException(storageType, oobEntry.Value);
}
// Define assembly and module.
using (var assemblyDefinition = AssemblyDefinition.CreateAssembly(
assemblyName: new AssemblyNameDefinition(assemblyName, new Version(1, 0, 0, 0)),
moduleName: $"{assemblyName}.dll",
ModuleKind.Dll))
{
// Set the module id to a hash of the enum-definition, this way it should be pretty
// unique while still being deterministic.
assemblyDefinition.MainModule.Mvid = new Guid(enumDefinition.Get128BitHash());
// Get the required references.
var enumUnderlyingType = storageType.GetCecilTypeReference(
typeSystem: assemblyDefinition.MainModule.TypeSystem);
var enumBaseType = new TypeReference(
@namespace: "System",
name: "Enum",
module: assemblyDefinition.MainModule,
scope: assemblyDefinition.MainModule.TypeSystem.CoreLibrary);
// Create type definition for the enum.
var enumTypeDefinition = new TypeDefinition(
@namespace,
name: enumDefinition.Identifier,
attributes: TypeAttributes.Public | TypeAttributes.Sealed,
baseType: enumBaseType);
// Add the storage field of the enum.
enumTypeDefinition.Fields.Add(new FieldDefinition(
name: "value__",
FieldAttributes.Public | FieldAttributes.SpecialName | FieldAttributes.RTSpecialName,
fieldType: enumUnderlyingType));
// Add the enum entries.
foreach (var entry in enumDefinition.Entries)
{
var entryField = new FieldDefinition(
name: entry.Name,
attributes:
FieldAttributes.Public |
FieldAttributes.Static |
FieldAttributes.Literal |
FieldAttributes.HasDefault,
fieldType: enumTypeDefinition);
// Set the value of the entry.
entryField.Constant = storageType.Cast(entry.Value);
enumTypeDefinition.Fields.Add(entryField);
}
// Add enum to module.
assemblyDefinition.MainModule.Types.Add(enumTypeDefinition);
// Write the pe dll file.
using (var memoryStream = new MemoryStream())
{
// Supply '0' as the timestamp to make the export deterministic.
var writerParams = new WriterParameters
{
Timestamp = 0
};
assemblyDefinition.Write(memoryStream, writerParams);
return(memoryStream.ToArray());
}
}
}
