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Port the check for illegal type recursion to the EnsureLoadableType implementation #91707

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Merged
merged 1 commit into from
Sep 7, 2023
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Merged

Port the check for illegal type recursion to the EnsureLoadableType implementation #91707

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12 changes: 11 additions & 1 deletion src/coreclr/tools/Common/Compiler/CompilerTypeSystemContext.Validation.cs
View file
Original file line number Diff line number Diff line change
@@ -4,6 +4,7 @@
using System;
using System.Collections.Generic;
using Internal.TypeSystem;
using Internal.TypeSystem.Ecma;

using Debug = System.Diagnostics.Debug;

@@ -301,11 +302,20 @@ private static TypeDesc EnsureLoadableTypeUncached(TypeDesc type)
// Validate classes, structs, enums, interfaces, and delegates
Debug.Assert(type.IsDefType);

// Don't validate generic definitions
// Don't validate generic definitions much other than by checking for illegal recursion.
if (type.IsGenericDefinition)
{
// Check for illegal recursion
if (type is EcmaType ecmaType && ILCompiler.LazyGenericsSupport.CheckForECMAIllegalGenericRecursion(ecmaType))
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadGeneral, type);
}
return type;
}
else if (type.HasInstantiation)
{
((CompilerTypeSystemContext)type.Context).EnsureLoadableType(type.GetTypeDefinition());
}

// System.__Canon or System.__UniversalCanon
if (type.IsCanonicalDefinitionType(CanonicalFormKind.Any))
141 changes: 141 additions & 0 deletions src/coreclr/tools/Common/Compiler/GenericCycleDetection/GraphBuilder.cs
View file
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Collections.Generic;
using System.Reflection.Metadata;
using System.Reflection.Metadata.Ecma335;

@@ -14,6 +15,146 @@ internal static partial class LazyGenericsSupport
{
private sealed partial class GraphBuilder
{
// Generate the illegal recursion graph as specified in ECMA 335 II.9.2 Generics and recursive inheritance graphs
public GraphBuilder(EcmaType type)
{
_graph = new Graph<EcmaGenericParameter>();

if (type.HasInstantiation)
{
HashSet<TypeDesc> types = new HashSet<TypeDesc>();
List<TypeDesc> typesToProcess = new List<TypeDesc>();
typesToProcess.Add(type);
while (typesToProcess.Count > 0)
{
var processType = typesToProcess[typesToProcess.Count - 1];
typesToProcess.RemoveAt(typesToProcess.Count - 1);

if (processType.IsParameterizedType)
{
if (processType.GetParameterType() is InstantiatedType instantiatedType)
{
AddProcessType(instantiatedType.GetTypeDefinition());
WalkFormals(instantiatedType, expanded: true);
}
}
else if (processType.GetTypeDefinition() == processType)
{
if (processType.HasInstantiation && processType is EcmaType ecmaProcessType)
{
AddSpecializedType(ecmaProcessType.BaseType);
foreach (var t in ecmaProcessType.ExplicitlyImplementedInterfaces)
{
AddSpecializedType(t);
}

void AddSpecializedType(TypeDesc typeToSpecialize)
{
if (typeToSpecialize != null)
{
var specializedType = typeToSpecialize.InstantiateSignature(processType.Instantiation, default(Instantiation));
AddProcessType(specializedType);
}
}
}
}
else if (processType is InstantiatedType instantiatedType)
{
AddProcessType(instantiatedType.GetTypeDefinition());
WalkFormals(instantiatedType, expanded: false);
}

void WalkFormals(InstantiatedType instantiatedType, bool expanded)
{
for (int i = 0; i < instantiatedType.Instantiation.Length; i++)
{
var formal = instantiatedType.GetTypeDefinition().Instantiation[i] as GenericParameterDesc;
if (instantiatedType.Instantiation[i] is GenericParameterDesc genParam)
{
AddEdge(genParam, formal, expanded);
}
else
{
foreach (var genParameter in GetGenericParameters(instantiatedType.Instantiation[i]))
{
AddEdge(genParameter, formal, true);
}
}
}
}

void AddProcessType(TypeDesc type)
{
if (type == null)
return;

if (types.Add(type))
{
typesToProcess.Add(type);
}

if (type is ParameterizedType paramType)
{
AddProcessType(paramType.GetParameterType());
}

foreach (var instType in type.Instantiation)
{
AddProcessType(instType);
}
}

void AddEdge(GenericParameterDesc from, GenericParameterDesc to, bool flagged)
{
EcmaGenericParameter fromEcma = from as EcmaGenericParameter;
EcmaGenericParameter toEcma = to as EcmaGenericParameter;
if (fromEcma == null || toEcma == null)
return;
_graph.AddEdge(fromEcma, toEcma, flagged);
}

IEnumerable<GenericParameterDesc> GetGenericParameters(TypeDesc t)
{
if (t is GenericParameterDesc genParamDesc)
{
yield return genParamDesc;
}
else if (t is ParameterizedType paramType)
{
foreach (var genParamType in GetGenericParameters(paramType.GetParameterType()))
{
yield return genParamType;
}
}
else if (t.HasInstantiation)
{
foreach (var instType in t.Instantiation)
{
foreach (var genParamType in GetGenericParameters(instType))
{
yield return genParamType;
}
}
}
else if (t is FunctionPointerType fptrType)
{
foreach (var genParamType in GetGenericParameters(fptrType.Signature.ReturnType))
{
yield return genParamType;
}
foreach (var parameterType in fptrType.Signature)
{
foreach (var genParamType in GetGenericParameters(parameterType))
{
yield return genParamType;
}
}
}
}
}
}
}

public GraphBuilder(EcmaModule assembly)
{
_graph = new Graph<EcmaGenericParameter>();
16 changes: 16 additions & 0 deletions src/coreclr/tools/Common/Compiler/GenericCycleDetection/ModuleCycleInfo.cs
View file
Original file line number Diff line number Diff line change
@@ -72,6 +72,22 @@ protected override ModuleCycleInfo CreateValueFromKey(EcmaModule key)
}
}

internal static bool CheckForECMAIllegalGenericRecursion(EcmaType type)
{
GraphBuilder gb = new GraphBuilder(type);
Graph<EcmaGenericParameter> graph = gb.Graph;

var flaggedCycleData = graph.ComputeVerticesInvolvedInAFlaggedCycle();

foreach (var _ in flaggedCycleData)
{
// If the list isn't empty, there is an illegal generic recursion
return true;
}

return false;
}

internal sealed class GenericCycleDetector
{
private readonly CycleInfoHashtable _hashtable = new CycleInfoHashtable();