private bool CompareTypeSigs(ref NativeParser parser1, ref NativeParser parser2)
{
// startOffset lets us backtrack to the TypeSignatureKind for external types since the TypeLoader
// expects to read it in.
uint data1;
uint startOffset1 = parser1.Offset;
var typeSignatureKind1 = parser1.GetTypeSignatureKind(out data1);
// If the parser is at a lookback type, get a new parser for it and recurse.
// Since we haven't read the element type of parser2 yet, we just pass it in unchanged
if (typeSignatureKind1 == TypeSignatureKind.Lookback)
{
NativeParser lookbackParser1 = parser1.GetLookbackParser(data1);
return CompareTypeSigs(ref lookbackParser1, ref parser2);
}
uint data2;
uint startOffset2 = parser2.Offset;
var typeSignatureKind2 = parser2.GetTypeSignatureKind(out data2);
// If parser2 is a lookback type, we need to rewind parser1 to its startOffset1
// before recursing.
if (typeSignatureKind2 == TypeSignatureKind.Lookback)
{
NativeParser lookbackParser2 = parser2.GetLookbackParser(data2);
parser1 = new NativeParser(parser1.Reader, startOffset1);
return CompareTypeSigs(ref parser1, ref lookbackParser2);
}
if (typeSignatureKind1 != typeSignatureKind2)
return false;
switch (typeSignatureKind1)
{
case TypeSignatureKind.Lookback:
{
// Recursion above better have removed all lookbacks
Debug.Assert(false, "Unexpected lookback type");
return false;
}
case TypeSignatureKind.Modifier:
{
// Ensure the modifier kind (vector, pointer, byref) is the same
if (data1 != data2)
return false;
return CompareTypeSigs(ref parser1, ref parser2);
}
case TypeSignatureKind.Variable:
{
// variable index is in data
if (data1 != data2)
return false;
break;
}
case TypeSignatureKind.MultiDimArray:
{
// rank is in data
if (data1 != data2)
return false;
if (!CompareTypeSigs(ref parser1, ref parser2))
return false;
uint boundCount1 = parser1.GetUnsigned();
uint boundCount2 = parser2.GetUnsigned();
if (boundCount1 != boundCount2)
return false;
for (uint i = 0; i < boundCount1; i++)
{
if (parser1.GetUnsigned() != parser2.GetUnsigned())
return false;
}
uint lowerBoundCount1 = parser1.GetUnsigned();
uint lowerBoundCount2 = parser2.GetUnsigned();
if (lowerBoundCount1 != lowerBoundCount2)
return false;
for (uint i = 0; i < lowerBoundCount1; i++)
{
if (parser1.GetUnsigned() != parser2.GetUnsigned())
return false;
}
break;
}
case TypeSignatureKind.FunctionPointer:
{
// callingConvention is in data
if (data1 != data2)
return false;
uint argCount1 = parser1.GetUnsigned();
uint argCount2 = parser2.GetUnsigned();
if (argCount1 != argCount2)
return false;
for (uint i = 0; i < argCount1; i++)
{
if (!CompareTypeSigs(ref parser1, ref parser2))
return false;
}
break;
}
case TypeSignatureKind.Instantiation:
{
// Type parameter count is in data
if (data1 != data2)
return false;
if (!CompareTypeSigs(ref parser1, ref parser2))
return false;
for (uint i = 0; i < data1; i++)
{
if (!CompareTypeSigs(ref parser1, ref parser2))
return false;
}
break;
}
case TypeSignatureKind.External:
{
RuntimeTypeHandle typeHandle1 = GetExternalTypeHandle(ref parser1, data1);
RuntimeTypeHandle typeHandle2 = GetExternalTypeHandle(ref parser2, data2);
if (!typeHandle1.Equals(typeHandle2))
return false;
break;
}
default:
return false;
}
return true;
}
/// <summary>
/// IF THESE SEMANTICS EVER CHANGE UPDATE THE LOGIC WHICH DEFINES THIS BEHAVIOR IN
/// THE DYNAMIC TYPE LOADER AS WELL AS THE COMPILER.
///
/// Parameter's are considered to have type layout dependent on their generic instantiation
/// if the type of the parameter in its signature is a type variable, or if the type is a generic
/// structure which meets 2 characteristics:
/// 1. Structure size/layout is affected by the size/layout of one or more of its generic parameters
/// 2. One or more of the generic parameters is a type variable, or a generic structure which also recursively
/// would satisfy constraint 2. (Note, that in the recursion case, whether or not the structure is affected
/// by the size/layout of its generic parameters is not investigated.)
///
/// Examples parameter types, and behavior.
///
/// T -> true
/// List<T> -> false
/// StructNotDependentOnArgsForSize<T> -> false
/// GenStructDependencyOnArgsForSize<T> -> true
/// StructNotDependentOnArgsForSize<GenStructDependencyOnArgsForSize<T>> -> true
/// StructNotDependentOnArgsForSize<GenStructDependencyOnArgsForSize<List<T>>>> -> false
///
/// Example non-parameter type behavior
/// T -> true
/// List<T> -> false
/// StructNotDependentOnArgsForSize<T> -> *true*
/// GenStructDependencyOnArgsForSize<T> -> true
/// StructNotDependentOnArgsForSize<GenStructDependencyOnArgsForSize<T>> -> true
/// StructNotDependentOnArgsForSize<GenStructDependencyOnArgsForSize<List<T>>>> -> false
/// </summary>
private bool TypeSignatureHasVarsNeedingCallingConventionConverter(ref NativeParser parser, TypeSystemContext context, HasVarsInvestigationLevel investigationLevel)
{
uint data;
var kind = parser.GetTypeSignatureKind(out data);
switch (kind)
{
case TypeSignatureKind.External: return false;
case TypeSignatureKind.Variable: return true;
case TypeSignatureKind.Lookback:
{
var lookbackParser = parser.GetLookbackParser(data);
return TypeSignatureHasVarsNeedingCallingConventionConverter(ref lookbackParser, context, investigationLevel);
}
case TypeSignatureKind.Instantiation:
{
RuntimeTypeHandle genericTypeDef;
if (!TryGetTypeFromSimpleTypeSignature(ref parser, out genericTypeDef))
{
Debug.Assert(false);
return true; // Returning true will prevent further reading from the native parser
}
if (!RuntimeAugments.IsValueType(genericTypeDef))
{
// Reference types are treated like pointers. No calling convention conversion needed. Just consume the rest of the signature.
for (uint i = 0; i < data; i++)
TypeSignatureHasVarsNeedingCallingConventionConverter(ref parser, context, HasVarsInvestigationLevel.Ignore);
return false;
}
else
{
bool result = false;
for (uint i = 0; i < data; i++)
result = TypeSignatureHasVarsNeedingCallingConventionConverter(ref parser, context, HasVarsInvestigationLevel.NotParameter) || result;
if ((result == true) && (investigationLevel == HasVarsInvestigationLevel.Parameter))
{
if (!TryComputeHasInstantiationDeterminedSize(genericTypeDef, context, out result))
Environment.FailFast("Unable to setup calling convention converter correctly");
return result;
}
return result;
}
}
case TypeSignatureKind.Modifier:
{
// Arrays, pointers and byref types signatures are treated as pointers, not requiring calling convention conversion.
// Just consume the parameter type from the stream and return false;
TypeSignatureHasVarsNeedingCallingConventionConverter(ref parser, context, HasVarsInvestigationLevel.Ignore);
return false;
}
case TypeSignatureKind.MultiDimArray:
{
// No need for a calling convention converter for this case. Just consume the signature from the stream.
TypeSignatureHasVarsNeedingCallingConventionConverter(ref parser, context, HasVarsInvestigationLevel.Ignore);
uint boundCount = parser.GetUnsigned();
for (uint i = 0; i < boundCount; i++)
parser.GetUnsigned();
uint lowerBoundCount = parser.GetUnsigned();
for (uint i = 0; i < lowerBoundCount; i++)
parser.GetUnsigned();
}
return false;
case TypeSignatureKind.FunctionPointer:
{
// No need for a calling convention converter for this case. Just consume the signature from the stream.
uint argCount = parser.GetUnsigned();
for (uint i = 0; i < argCount; i++)
TypeSignatureHasVarsNeedingCallingConventionConverter(ref parser, context, HasVarsInvestigationLevel.Ignore);
}
return false;
default:
parser.ThrowBadImageFormatException();
return true;
}
}
private bool TryGetTypeFromSimpleTypeSignature(ref NativeParser parser, out RuntimeTypeHandle typeHandle)
{
uint data;
TypeSignatureKind kind = parser.GetTypeSignatureKind(out data);
if (kind == TypeSignatureKind.Lookback)
{
var lookbackParser = parser.GetLookbackParser(data);
return TryGetTypeFromSimpleTypeSignature(ref lookbackParser, out typeHandle);
}
else if (kind == TypeSignatureKind.External)
{
typeHandle = GetExternalTypeHandle(ref parser, data);
return true;
}
// Not a simple type signature... requires more work to skip
typeHandle = default(RuntimeTypeHandle);
return false;
}
private unsafe TypeDesc GetLookbackType(ref NativeParser parser, uint lookback)
{
var lookbackParser = parser.GetLookbackParser(lookback);
return GetType(ref lookbackParser);
}