internal static Type ResolveTypeNameWithContext(TypeName typeName, out Exception exception, Assembly[] assemblies, TypeResolutionState typeResolutionState)
{
ExecutionContext context = null;
exception = null;
if (typeResolutionState == null)
{
// Usings from script scope (and if no script scope, fall back to default 'using namespace system')
context = LocalPipeline.GetExecutionContextFromTLS();
typeResolutionState = TypeResolutionState.GetDefaultUsingState(context);
}
// We can do the cache lookup only if we don't define type in the current scope (cache would be invalid in this case).
var result = typeResolutionState.ContainsTypeDefined(typeName.Name)
? null
: TypeCache.Lookup(typeName, typeResolutionState);
if (result != null)
{
return(result);
}
if (typeName.AssemblyName != null)
{
result = ResolveAssemblyQualifiedTypeName(typeName, out exception);
TypeCache.Add(typeName, typeResolutionState, result);
return(result);
}
// Simple typename (no generics, no arrays, no assembly name)
// We use the following search order, using the specified name (assumed to be fully namespace qualified):
//
// * Search scope table (includes 'using type x = ...' aliases)
// * Built in type accelerators (implicit 'using type x = ...' aliases that are effectively in global scope
// * typeResolutionState.assemblies, which contains:
// - Assemblies with PS types, added by 'using module'
// - Assemblies added by 'using assembly'.
// For this case, we REPORT ambiguity, since user explicitly specifies the set of assemblies.
// * All other loaded assemblies (excluding dynamic assemblies created for PS defined types).
// IGNORE ambiguity. It mimics PS v4. There are two reasons:
// 1) If we report ambiguity, we need to fix our caching logic accordingly.
// Consider this code
// Add-Type 'public class Q {}' # ok
// Add-Type 'public class Q { }' # get error about the same name
// [Q] # we would get error about ambiguous type, because we added assembly with duplicated type
// # before we can report TYPE_ALREADY_EXISTS error.
//
// Add-Type 'public class Q2 {}' # ok
// [Q2] # caching Q2 type
// Add-Type 'public class Q2 { }' # get error about the same name
// [Q2] # we don't get an error about ambiguous type, because it's cached already
// 2) NuGet (VS Package Management console) uses MEF extensibility model.
// Different assemblies includes same interface (i.e. NuGet.VisualStudio.IVsPackageInstallerServices),
// where they include only methods that they are interested in the interface declaration (result interfaces are different!).
// Then, at runtime VS provides an instance. Everything work as far as instance has compatible API.
// So [NuGet.VisualStudio.IVsPackageInstallerServices] can be resolved to several different assemblies and it's ok.
// * User defined type accelerators (rare - interface was never public)
//
// If nothing is found, we search again, this time applying any 'using namespace ...' declarations including the implicit 'using namespace System'.
// We must search all using aliases and REPORT an error if there is an ambiguity.
var assemList = assemblies ?? ClrFacade.GetAssemblies(typeResolutionState, typeName);
if (context == null)
{
context = LocalPipeline.GetExecutionContextFromTLS();
}
SessionStateScope currentScope = null;
if (context != null)
{
currentScope = context.EngineSessionState.CurrentScope;
}
// If this is TypeDefinition we should not cache anything in TypeCache.
if (typeName._typeDefinitionAst != null)
{
return(typeName._typeDefinitionAst.Type);
}
result = ResolveTypeNameWorker(typeName, currentScope, typeResolutionState.assemblies, typeResolutionState, /* reportAmbigousException */ true, out exception);
if (exception == null && result == null)
{
result = ResolveTypeNameWorker(typeName, currentScope, assemList, typeResolutionState, /* reportAmbigousException */ false, out exception);
}
if (result != null)
{
TypeCache.Add(typeName, typeResolutionState, result);
return(result);
}
if (exception == null)
{
foreach (var ns in typeResolutionState.namespaces)
{
var newTypeNameToSearch = ns + "." + typeName.Name;
newTypeNameToSearch = typeResolutionState.GetAlternateTypeName(newTypeNameToSearch) ??
newTypeNameToSearch;
var newTypeName = new TypeName(typeName.Extent, newTypeNameToSearch);
#if CORECLR
if (assemblies == null)
{
// We called 'ClrFacade.GetAssemblies' to get assemblies. That means the assemblies to search from
// are not pre-defined, and thus we have to refetch assembly again based on the new type name.
assemList = ClrFacade.GetAssemblies(typeResolutionState, newTypeName);
}
#endif
var newResult = ResolveTypeNameWorker(newTypeName, currentScope, typeResolutionState.assemblies, typeResolutionState, /* reportAmbigousException */ true, out exception);
if (exception == null && newResult == null)
{
newResult = ResolveTypeNameWorker(newTypeName, currentScope, assemList, typeResolutionState, /* reportAmbigousException */ false, out exception);
}
if (exception != null)
{
break;
}
if (newResult != null)
{
if (result == null)
{
result = newResult;
}
else
{
exception = new AmbiguousTypeException(typeName, new string[] { result.FullName, newResult.FullName });
result = null;
break;
}
}
}
}
if (exception != null)
{
// AmbiguousTypeException is for internal representation only.
var ambiguousException = exception as AmbiguousTypeException;
if (ambiguousException != null)
{
exception = new PSInvalidCastException("AmbiguousTypeReference", exception,
ParserStrings.AmbiguousTypeReference, ambiguousException.TypeName.Name,
ambiguousException.Candidates[0], ambiguousException.Candidates[1]);
}
}
if (result != null)
{
TypeCache.Add(typeName, typeResolutionState, result);
}
return(result);
}