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|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Text;
using TypeDefinition = Mono.Cecil.TypeDefinition;
using FieldDefinition = Mono.Cecil.FieldDefinition;
using GenericParameter = Mono.Cecil.GenericParameter;
using Mono.Cecil;
namespace Mono.Linker.Dataflow
{
public enum ValueNodeKind
{
Invalid, // in case the Kind field is not initialized properly
Unknown, // unknown value, has StaticType from context
Null, // known value
SystemType, // known value - TypeRepresented
RuntimeTypeHandle, // known value - TypeRepresented
KnownString, // known value - Contents
ConstInt, // known value - Int32
AnnotatedString, // string with known annotation
MethodParameter, // symbolic placeholder
MethodReturn, // symbolic placeholder
RuntimeTypeHandleForGenericParameter, // symbolic placeholder for generic parameter
SystemTypeForGenericParameter, // symbolic placeholder for generic parameter
MergePoint, // structural, multiplexer - Values
GetTypeFromString, // structural, could be known value - KnownString
Array, // structural, could be known value - Array
LoadField, // structural, could be known value - InstanceValue
}
/// <summary>
/// A ValueNode represents a value in the IL dataflow analysis. It may not contain complete information as it is a
/// best-effort representation. Additionally, as the analysis is linear and does not account for control flow, any
/// given ValueNode may represent multiple values simultaneously. (This occurs, for example, at control flow join
/// points when both paths yield values on the IL stack or in a local.)
/// </summary>
public abstract class ValueNode : IEquatable<ValueNode>
{
public ValueNode ()
{
#if false // Helpful for debugging a cycle that has inadvertently crept into the graph
if (this.DetectCycle(new HashSet<ValueNode>()))
{
throw new Exception("Found a cycle");
}
#endif
}
/// <summary>
/// The 'kind' of value node -- this represents the most-derived type and allows us to switch over and do
/// equality checks without the cost of casting. Intermediate non-leaf types in the ValueNode hierarchy should
/// be abstract.
/// </summary>
public ValueNodeKind Kind { get; protected set; }
/// <summary>
/// Allows the enumeration of the direct children of this node. The ChildCollection struct returned here
/// supports 'foreach' without allocation.
/// </summary>
public ChildCollection Children { get { return new ChildCollection (this); } }
/// <summary>
/// This property allows you to enumerate all 'unique values' represented by a given ValueNode. The basic idea
/// is that there will be no MergePointValues in the returned ValueNodes and all structural operations will be
/// applied so that each 'unique value' can be considered on its own without regard to the structure that led to
/// it.
/// </summary>
public UniqueValueCollection UniqueValues {
get {
return new UniqueValueCollection (this);
}
}
/// <summary>
/// This protected method is how nodes implement the UniqueValues property. It is protected because it returns
/// an IEnumerable and we want to avoid allocating an enumerator for the exceedingly common case of there being
/// only one value in the enumeration. The UniqueValueCollection returned by the UniqueValues property handles
/// this detail.
/// </summary>
protected abstract IEnumerable<ValueNode> EvaluateUniqueValues ();
/// <summary>
/// RepresentsExactlyOneValue is used by the UniqueValues property to allow us to bypass allocating an
/// enumerator to return just one value. If a node returns 'true' from RepresentsExactlyOneValue, it must also
/// return that one value from GetSingleUniqueValue. If it always returns 'false', it doesn't need to implement
/// GetSingleUniqueValue.
/// </summary>
protected virtual bool RepresentsExactlyOneValue { get { return false; } }
/// <summary>
/// GetSingleUniqueValue is called if, and only if, RepresentsExactlyOneValue returns true. It allows us to
/// bypass the allocation of an enumerator for the common case of returning exactly one value.
/// </summary>
protected virtual ValueNode GetSingleUniqueValue ()
{
// Not implemented because RepresentsExactlyOneValue returns false and, therefore, this method should be
// unreachable.
throw new NotImplementedException ();
}
protected abstract int NumChildren { get; }
protected abstract ValueNode ChildAt (int index);
public abstract bool Equals (ValueNode other);
public abstract override int GetHashCode ();
/// <summary>
/// Each node type must implement this to stringize itself. The expectation is that it is implemented using
/// ValueNodeDump.ValueNodeToString(), passing any non-ValueNode properties of interest (e.g.
/// SystemTypeValue.TypeRepresented). Properties that are invariant on a particular node type
/// should be omitted for clarity.
/// </summary>
protected abstract string NodeToString ();
public override string ToString ()
{
return NodeToString ();
}
public override bool Equals (object other)
{
if (!(other is ValueNode))
return false;
return this.Equals ((ValueNode) other);
}
#region Specialized Collection Nested Types
/// <summary>
/// ChildCollection struct is used to wrap the operations on a node involving its children. In particular, the
/// struct implements a GetEnumerator method that is used to allow "foreach (ValueNode node in myNode.Children)"
/// without heap allocations.
/// </summary>
public struct ChildCollection : IEnumerable<ValueNode>
{
/// <summary>
/// Enumerator for children of a ValueNode. Allows foreach(var child in node.Children) to work without
/// allocating a heap-based enumerator.
/// </summary>
public struct Enumerator : IEnumerator<ValueNode>
{
int _index;
ValueNode _parent;
public Enumerator (ValueNode parent)
{
_parent = parent;
_index = -1;
}
public ValueNode Current { get { return (_parent != null) ? _parent.ChildAt (_index) : null; } }
object System.Collections.IEnumerator.Current { get { return Current; } }
public bool MoveNext ()
{
_index++;
return (_parent != null) ? (_index < _parent.NumChildren) : false;
}
public void Reset ()
{
_index = -1;
}
public void Dispose ()
{
}
}
ValueNode _parentNode;
public ChildCollection (ValueNode parentNode) { _parentNode = parentNode; }
// Used by C# 'foreach', when strongly typed, to avoid allocation.
public Enumerator GetEnumerator ()
{
return new Enumerator (_parentNode);
}
IEnumerator<ValueNode> IEnumerable<ValueNode>.GetEnumerator ()
{
// note the boxing!
return (IEnumerator<ValueNode>) new Enumerator (_parentNode);
}
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator ()
{
// note the boxing!
return (System.Collections.IEnumerator) new Enumerator (_parentNode);
}
public int Count { get { return (_parentNode != null) ? _parentNode.NumChildren : 0; } }
}
/// <summary>
/// UniqueValueCollection is used to wrap calls to ValueNode.EvaluateUniqueValues. If a ValueNode represents
/// only one value, then foreach(ValueNode value in node.UniqueValues) will not allocate a heap-based enumerator.
///
/// This is implented by having each ValueNode tell us whether or not it represents exactly one value or not.
/// If it does, we fetch it with ValueNode.GetSingleUniqueValue(), otherwise, we fall back to the usual heap-
/// based IEnumerable returned by ValueNode.EvaluateUniqueValues.
/// </summary>
public struct UniqueValueCollection : IEnumerable<ValueNode>
{
IEnumerable<ValueNode> _multiValueEnumerable;
ValueNode _treeNode;
public UniqueValueCollection (ValueNode node)
{
if (node.RepresentsExactlyOneValue) {
_multiValueEnumerable = null;
_treeNode = node;
} else {
_multiValueEnumerable = node.EvaluateUniqueValues ();
_treeNode = null;
}
}
public Enumerator GetEnumerator ()
{
return new Enumerator (_treeNode, _multiValueEnumerable);
}
IEnumerator<ValueNode> IEnumerable<ValueNode>.GetEnumerator ()
{
if (_multiValueEnumerable != null) {
return _multiValueEnumerable.GetEnumerator ();
}
// note the boxing!
return (IEnumerator<ValueNode>) GetEnumerator ();
}
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator ()
{
if (_multiValueEnumerable != null) {
return _multiValueEnumerable.GetEnumerator ();
}
// note the boxing!
return (System.Collections.IEnumerator) GetEnumerator ();
}
public struct Enumerator : IEnumerator<ValueNode>
{
IEnumerator<ValueNode> _multiValueEnumerator;
ValueNode _singleValueNode;
int _index;
public Enumerator (ValueNode treeNode, IEnumerable<ValueNode> mulitValueEnumerable)
{
_singleValueNode = (treeNode != null) ? treeNode.GetSingleUniqueValue () : null;
_multiValueEnumerator = (mulitValueEnumerable != null) ? mulitValueEnumerable.GetEnumerator () : null;
_index = -1;
}
public void Reset ()
{
if (_multiValueEnumerator != null) {
_multiValueEnumerator.Reset ();
return;
}
_index = -1;
}
public bool MoveNext ()
{
if (_multiValueEnumerator != null)
return _multiValueEnumerator.MoveNext ();
_index++;
return (_index == 0);
}
public ValueNode Current {
get {
if (_multiValueEnumerator != null)
return _multiValueEnumerator.Current;
if (_index == 0)
return _singleValueNode;
throw new InvalidOperationException ();
}
}
object System.Collections.IEnumerator.Current { get { return Current; } }
public void Dispose ()
{
}
}
}
#endregion
}
/// <summary>
/// LeafValueNode represents a 'leaf' in the expression tree. In other words, the node has no ValueNode children.
/// It *may* still have non-ValueNode 'properties' that are interesting. This class serves, primarily, as a way to
/// collect up the very common implmentation of NumChildren/ChildAt for leaf nodes and the "represents exactly one
/// value" optimization. These things aren't on the ValueNode base class because, otherwise, new node types
/// deriving from ValueNode may 'forget' to implement these things. So this class allows them to remain abstract in
/// ValueNode while still having a common implementation for all the leaf nodes.
/// </summary>
public abstract class LeafValueNode : ValueNode
{
protected override int NumChildren { get { return 0; } }
protected override ValueNode ChildAt (int index) { throw new InvalidOperationException (); }
protected override bool RepresentsExactlyOneValue { get { return true; } }
protected override ValueNode GetSingleUniqueValue () { return this; }
protected override IEnumerable<ValueNode> EvaluateUniqueValues ()
{
// Leaf values should not represent more than one value. This method should be unreachable as long as
// RepresentsExactlyOneValue returns true.
throw new NotImplementedException ();
}
}
// These are extension methods because we want to allow the use of them on null 'this' pointers.
internal static class ValueNodeExtensions
{
/// <summary>
/// Returns true if a ValueNode graph contains a cycle
/// </summary>
/// <param name="node">Node to evaluate</param>
/// <param name="seenNodes">Set of nodes previously seen on the current arc. Callers may pass a non-empty set
/// to test whether adding that set to this node would create a cycle. Contents will be modified by the walk
/// and should not be used by the caller after returning</param>
/// <param name="allNodesSeen">Optional. The set of all nodes encountered during a walk after DetectCycle returns</param>
/// <returns></returns>
public static bool DetectCycle (this ValueNode node, HashSet<ValueNode> seenNodes, HashSet<ValueNode> allNodesSeen)
{
if (node == null)
return false;
if (seenNodes.Contains (node))
return true;
seenNodes.Add (node);
if (allNodesSeen != null) {
allNodesSeen.Add (node);
}
bool foundCycle = false;
switch (node.Kind) {
//
// Leaf nodes
//
case ValueNodeKind.Unknown:
case ValueNodeKind.Null:
case ValueNodeKind.SystemType:
case ValueNodeKind.RuntimeTypeHandle:
case ValueNodeKind.KnownString:
case ValueNodeKind.AnnotatedString:
case ValueNodeKind.ConstInt:
case ValueNodeKind.MethodParameter:
case ValueNodeKind.MethodReturn:
case ValueNodeKind.SystemTypeForGenericParameter:
case ValueNodeKind.RuntimeTypeHandleForGenericParameter:
case ValueNodeKind.LoadField:
break;
//
// Nodes with children
//
case ValueNodeKind.MergePoint:
foreach (ValueNode val in ((MergePointValue) node).Values) {
if (val.DetectCycle (seenNodes, allNodesSeen)) {
foundCycle = true;
}
}
break;
case ValueNodeKind.GetTypeFromString:
GetTypeFromStringValue gtfsv = (GetTypeFromStringValue) node;
foundCycle = gtfsv.AssemblyIdentity.DetectCycle (seenNodes, allNodesSeen);
foundCycle |= gtfsv.NameString.DetectCycle (seenNodes, allNodesSeen);
break;
case ValueNodeKind.Array:
ArrayValue av = (ArrayValue) node;
foundCycle = av.Size.DetectCycle (seenNodes, allNodesSeen);
break;
default:
throw new Exception (String.Format ("Unknown node kind: {0}", node.Kind));
}
seenNodes.Remove (node);
return foundCycle;
}
public static ValueNode.UniqueValueCollection UniqueValues (this ValueNode node)
{
if (node == null)
return new ValueNode.UniqueValueCollection (UnknownValue.Instance);
return node.UniqueValues;
}
public static int? AsConstInt (this ValueNode node)
{
if (node is ConstIntValue constInt)
return constInt.Value;
return null;
}
}
static internal class ValueNodeDump
{
internal static string ValueNodeToString (ValueNode node, params object[] args)
{
if (node == null)
return "<null>";
StringBuilder sb = new StringBuilder ();
sb.Append (node.Kind.ToString ());
sb.Append ("(");
if (args != null) {
for (int i = 0; i < args.Length; i++) {
if (i > 0)
sb.Append (",");
sb.Append (args[i] == null ? "<null>" : args[i].ToString ());
}
}
sb.Append (")");
return sb.ToString ();
}
static string GetIndent (int level)
{
StringBuilder sb = new StringBuilder (level * 2);
for (int i = 0; i < level; i++)
sb.Append (" ");
return sb.ToString ();
}
public static void DumpTree (this ValueNode node, System.IO.TextWriter writer = null, int indentLevel = 0)
{
if (writer == null)
writer = Console.Out;
writer.Write (GetIndent (indentLevel));
if (node == null) {
writer.WriteLine ("<null>");
return;
}
writer.WriteLine (node);
foreach (ValueNode child in node.Children) {
child.DumpTree (writer, indentLevel + 1);
}
}
}
/// <summary>
/// Represents an unknown value.
/// </summary>
class UnknownValue : LeafValueNode
{
private UnknownValue ()
{
Kind = ValueNodeKind.Unknown;
}
public static UnknownValue Instance { get; } = new UnknownValue ();
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
return true;
}
public override int GetHashCode ()
{
// All instances of UnknownValue are equivalent, so they all hash to the same hashcode. This one was
// chosen for no particular reason at all.
return 0x98052;
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this);
}
}
class NullValue : LeafValueNode
{
private NullValue ()
{
Kind = ValueNodeKind.Null;
}
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
return true;
}
public static NullValue Instance { get; } = new NullValue ();
public override int GetHashCode ()
{
// All instances of NullValue are equivalent, so they all hash to the same hashcode. This one was
// chosen for no particular reason at all.
return 0x90210;
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this);
}
}
/// <summary>
/// This is a known System.Type value. TypeRepresented is the 'value' of the System.Type..
/// </summary>
class SystemTypeValue : LeafValueNode
{
public SystemTypeValue (TypeDefinition typeRepresented)
{
Kind = ValueNodeKind.SystemType;
TypeRepresented = typeRepresented;
}
public TypeDefinition TypeRepresented { get; private set; }
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
return Equals (this.TypeRepresented, ((SystemTypeValue) other).TypeRepresented);
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, TypeRepresented);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, TypeRepresented);
}
}
/// <summary>
/// This is the System.RuntimeTypeHandle equivalent to a <see cref="SystemTypeValue"/> node.
/// </summary>
class RuntimeTypeHandleValue : LeafValueNode
{
public RuntimeTypeHandleValue (TypeDefinition typeRepresented)
{
Kind = ValueNodeKind.RuntimeTypeHandle;
TypeRepresented = typeRepresented;
}
public TypeDefinition TypeRepresented { get; }
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
return Equals (this.TypeRepresented, ((RuntimeTypeHandleValue) other).TypeRepresented);
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, TypeRepresented);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, TypeRepresented);
}
}
/// <summary>
/// This is a System.Type value which represents generic parameter (basically result of typeof(T))
/// Its actual type is unknown, but it can have annotations.
/// </summary>
class SystemTypeForGenericParameterValue : LeafValueWithDynamicallyAccessedMemberNode
{
public SystemTypeForGenericParameterValue (GenericParameter genericParameter, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes)
{
Kind = ValueNodeKind.SystemTypeForGenericParameter;
GenericParameter = genericParameter;
DynamicallyAccessedMemberTypes = dynamicallyAccessedMemberTypes;
SourceContext = genericParameter;
}
public GenericParameter GenericParameter { get; }
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
var otherValue = (SystemTypeForGenericParameterValue) other;
return this.GenericParameter == otherValue.GenericParameter && this.DynamicallyAccessedMemberTypes == otherValue.DynamicallyAccessedMemberTypes;
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, GenericParameter, DynamicallyAccessedMemberTypes);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, GenericParameter, DynamicallyAccessedMemberTypes);
}
}
/// <summary>
/// This is the System.RuntimeTypeHandle equivalent to a <see cref="SystemTypeForGenericParameterValue"/> node.
/// </summary>
class RuntimeTypeHandleForGenericParameterValue : LeafValueNode
{
public RuntimeTypeHandleForGenericParameterValue (GenericParameter genericParameter)
{
Kind = ValueNodeKind.RuntimeTypeHandleForGenericParameter;
GenericParameter = genericParameter;
}
public GenericParameter GenericParameter { get; }
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
return Equals (this.GenericParameter, ((RuntimeTypeHandleForGenericParameterValue) other).GenericParameter);
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, GenericParameter);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, GenericParameter);
}
}
/// <summary>
/// A known string - such as the result of a ldstr.
/// </summary>
class KnownStringValue : LeafValueNode
{
public KnownStringValue (string contents)
{
Kind = ValueNodeKind.KnownString;
Contents = contents;
}
public string Contents { get; private set; }
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
return this.Contents == ((KnownStringValue) other).Contents;
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, Contents);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, "\"" + Contents + "\"");
}
}
/// <summary>
/// Base class for all nodes which can have dynamically accessed member annotation.
/// </summary>
abstract class LeafValueWithDynamicallyAccessedMemberNode : LeafValueNode
{
public IMetadataTokenProvider SourceContext { get; protected set; }
/// <summary>
/// The bitfield of dynamically accessed member types the node guarantees
/// </summary>
public DynamicallyAccessedMemberTypes DynamicallyAccessedMemberTypes { get; protected set; }
}
/// <summary>
/// A value that came from a method parameter - such as the result of a ldarg.
/// </summary>
class MethodParameterValue : LeafValueWithDynamicallyAccessedMemberNode
{
public MethodParameterValue (int parameterIndex, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes, IMetadataTokenProvider sourceContext)
{
Kind = ValueNodeKind.MethodParameter;
ParameterIndex = parameterIndex;
DynamicallyAccessedMemberTypes = dynamicallyAccessedMemberTypes;
SourceContext = sourceContext;
}
public int ParameterIndex { get; }
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
var otherValue = (MethodParameterValue) other;
return this.ParameterIndex == otherValue.ParameterIndex && this.DynamicallyAccessedMemberTypes == otherValue.DynamicallyAccessedMemberTypes;
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, ParameterIndex, DynamicallyAccessedMemberTypes);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, ParameterIndex, DynamicallyAccessedMemberTypes);
}
}
/// <summary>
/// String with a known annotation.
/// </summary>
class AnnotatedStringValue : LeafValueWithDynamicallyAccessedMemberNode
{
public AnnotatedStringValue (IMetadataTokenProvider sourceContext, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes)
{
Kind = ValueNodeKind.AnnotatedString;
DynamicallyAccessedMemberTypes = dynamicallyAccessedMemberTypes;
SourceContext = sourceContext;
}
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
var otherValue = (AnnotatedStringValue) other;
return this.DynamicallyAccessedMemberTypes == otherValue.DynamicallyAccessedMemberTypes;
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, DynamicallyAccessedMemberTypes);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, DynamicallyAccessedMemberTypes);
}
}
/// <summary>
/// Return value from a method
/// </summary>
class MethodReturnValue : LeafValueWithDynamicallyAccessedMemberNode
{
public MethodReturnValue (MethodReturnType methodReturnType, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes)
{
Kind = ValueNodeKind.MethodReturn;
DynamicallyAccessedMemberTypes = dynamicallyAccessedMemberTypes;
SourceContext = methodReturnType;
}
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
var otherValue = (MethodReturnValue) other;
return this.DynamicallyAccessedMemberTypes == otherValue.DynamicallyAccessedMemberTypes;
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, DynamicallyAccessedMemberTypes);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, DynamicallyAccessedMemberTypes);
}
}
/// <summary>
/// A merge point commonly occurs due to control flow in a method body. It represents a set of values
/// from different paths through the method. It is the reason for EvaluateUniqueValues, which essentially
/// provides an enumeration over all the concrete values represented by a given ValueNode after 'erasing'
/// the merge point nodes.
/// </summary>
class MergePointValue : ValueNode
{
private MergePointValue (ValueNode one, ValueNode two)
{
Kind = ValueNodeKind.MergePoint;
m_values = new ValueNodeHashSet ();
if (one.Kind == ValueNodeKind.MergePoint) {
MergePointValue mpvOne = (MergePointValue) one;
foreach (ValueNode value in mpvOne.Values)
m_values.Add (value);
} else
m_values.Add (one);
if (two.Kind == ValueNodeKind.MergePoint) {
MergePointValue mpvTwo = (MergePointValue) two;
foreach (ValueNode value in mpvTwo.Values)
m_values.Add (value);
} else
m_values.Add (two);
}
public MergePointValue ()
{
Kind = ValueNodeKind.MergePoint;
m_values = new ValueNodeHashSet ();
}
public void AddValue (ValueNode node)
{
// we are mutating our state, so we must invalidate any cached knowledge
//InvalidateIsOpen ();
if (node.Kind == ValueNodeKind.MergePoint) {
foreach (ValueNode value in ((MergePointValue) node).Values)
m_values.Add (value);
} else
m_values.Add (node);
#if false
if (this.DetectCycle(new HashSet<ValueNode>()))
{
throw new Exception("Found a cycle");
}
#endif
}
ValueNodeHashSet m_values;
public ValueNodeHashSet Values { get { return m_values; } }
protected override int NumChildren { get { return Values.Count; } }
protected override ValueNode ChildAt (int index)
{
if (index < NumChildren)
return Values.ElementAt (index);
throw new InvalidOperationException ();
}
static public ValueNode MergeValues (ValueNode one, ValueNode two)
{
if (one == null)
return two;
else if (two == null)
return one;
else if (one.Equals (two))
return one;
else
return new MergePointValue (one, two);
}
protected override IEnumerable<ValueNode> EvaluateUniqueValues ()
{
foreach (ValueNode value in Values) {
foreach (ValueNode uniqueValue in value.UniqueValues) {
yield return uniqueValue;
}
}
}
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
MergePointValue otherMpv = (MergePointValue) other;
if (this.Values.Count != otherMpv.Values.Count)
return false;
foreach (ValueNode value in this.Values) {
if (!otherMpv.Values.Contains (value))
return false;
}
return true;
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, Values);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this);
}
}
delegate TypeDefinition TypeResolver (string assemblyString, string typeString);
/// <summary>
/// The result of a Type.GetType.
/// AssemblyIdentity is the scope in which to resolve if the type name string is not assembly-qualified.
/// </summary>
#pragma warning disable CA1812 // GetTypeFromStringValue is never instantiated
class GetTypeFromStringValue : ValueNode
{
private readonly TypeResolver _resolver;
public GetTypeFromStringValue (TypeResolver resolver, ValueNode assemblyIdentity, ValueNode nameString)
{
_resolver = resolver;
Kind = ValueNodeKind.GetTypeFromString;
AssemblyIdentity = assemblyIdentity;
NameString = nameString;
}
public ValueNode AssemblyIdentity { get; private set; }
public ValueNode NameString { get; private set; }
protected override int NumChildren { get { return 2; } }
protected override ValueNode ChildAt (int index)
{
if (index == 0) return AssemblyIdentity;
if (index == 1) return NameString;
throw new InvalidOperationException ();
}
protected override IEnumerable<ValueNode> EvaluateUniqueValues ()
{
HashSet<string> names = null;
foreach (ValueNode nameStringValue in NameString.UniqueValues) {
if (nameStringValue.Kind == ValueNodeKind.KnownString) {
if (names == null) {
names = new HashSet<string> ();
}
string typeName = ((KnownStringValue) nameStringValue).Contents;
names.Add (typeName);
}
}
bool foundAtLeastOne = false;
if (names != null) {
foreach (ValueNode assemblyValue in AssemblyIdentity.UniqueValues) {
if (assemblyValue.Kind == ValueNodeKind.KnownString) {
string assemblyName = ((KnownStringValue) assemblyValue).Contents;
foreach (string name in names) {
TypeDefinition typeDefinition = _resolver (assemblyName, name);
if (typeDefinition != null) {
foundAtLeastOne = true;
yield return new SystemTypeValue (typeDefinition);
}
}
}
}
}
if (!foundAtLeastOne)
yield return UnknownValue.Instance;
}
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
GetTypeFromStringValue otherGtfs = (GetTypeFromStringValue) other;
return this.AssemblyIdentity.Equals (otherGtfs.AssemblyIdentity) &&
this.NameString.Equals (otherGtfs.NameString);
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, AssemblyIdentity, NameString);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, NameString);
}
}
/// <summary>
/// A representation of a ldfld. Note that we don't have a representation of objects containing fields
/// so there isn't much that can be done with this node type yet.
/// </summary>
class LoadFieldValue : LeafValueWithDynamicallyAccessedMemberNode
{
public LoadFieldValue (FieldDefinition fieldToLoad, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes)
{
Kind = ValueNodeKind.LoadField;
Field = fieldToLoad;
DynamicallyAccessedMemberTypes = dynamicallyAccessedMemberTypes;
SourceContext = fieldToLoad;
}
public FieldDefinition Field { get; private set; }
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
LoadFieldValue otherLfv = (LoadFieldValue) other;
if (!Equals (this.Field, otherLfv.Field))
return false;
return this.DynamicallyAccessedMemberTypes == otherLfv.DynamicallyAccessedMemberTypes;
}
public override int GetHashCode ()
{
return HashCode.Combine (Kind, Field, DynamicallyAccessedMemberTypes);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, Field, DynamicallyAccessedMemberTypes);
}
}
/// <summary>
/// Represents a ldc on an int32.
/// </summary>
class ConstIntValue : LeafValueNode
{
public ConstIntValue (int value)
{
Kind = ValueNodeKind.ConstInt;
Value = value;
}
public int Value { get; private set; }
public override int GetHashCode ()
{
return HashCode.Combine (Kind, Value);
}
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
ConstIntValue otherCiv = (ConstIntValue) other;
return Value == otherCiv.Value;
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, Value);
}
}
class ArrayValue : ValueNode
{
protected override int NumChildren => 1;
/// <summary>
/// Constructs an array value of the given size
/// </summary>
public ArrayValue (ValueNode size)
{
Kind = ValueNodeKind.Array;
Size = size ?? UnknownValue.Instance;
}
public ValueNode Size { get; }
public override int GetHashCode ()
{
return HashCode.Combine (Kind, Size);
}
public override bool Equals (ValueNode other)
{
if (other == null)
return false;
if (this.Kind != other.Kind)
return false;
ArrayValue otherArr = (ArrayValue) other;
return Size.Equals (otherArr.Size);
}
protected override string NodeToString ()
{
return ValueNodeDump.ValueNodeToString (this, Size);
}
protected override IEnumerable<ValueNode> EvaluateUniqueValues ()
{
foreach (var sizeConst in Size.UniqueValues)
yield return new ArrayValue (sizeConst);
}
protected override ValueNode ChildAt (int index)
{
if (index == 0) return Size;
throw new InvalidOperationException ();
}
}
#region ValueNode Collections
public class ValueNodeList : List<ValueNode>
{
public ValueNodeList ()
{
}
public ValueNodeList (int capacity)
: base (capacity)
{
}
public ValueNodeList (List<ValueNode> other)
: base (other)
{
}
public override int GetHashCode ()
{
return HashUtils.CalcHashCodeEnumerable (this);
}
public override bool Equals (object other)
{
ValueNodeList otherList = other as ValueNodeList;
if (otherList == null)
return false;
if (otherList.Count != Count)
return false;
for (int i = 0; i < Count; i++) {
if (!otherList[i].Equals (this[i]))
return false;
}
return true;
}
}
class ValueNodeHashSet : HashSet<ValueNode>
{
public override int GetHashCode ()
{
return HashUtils.CalcHashCodeEnumerable (this);
}
public override bool Equals (object other)
{
ValueNodeHashSet otherSet = other as ValueNodeHashSet;
if (otherSet == null)
return false;
if (otherSet.Count != Count)
return false;
IEnumerator<ValueNode> thisEnumerator = this.GetEnumerator ();
IEnumerator<ValueNode> otherEnumerator = otherSet.GetEnumerator ();
for (int i = 0; i < Count; i++) {
thisEnumerator.MoveNext ();
otherEnumerator.MoveNext ();
if (!thisEnumerator.Current.Equals (otherEnumerator.Current))
return false;
}
return true;
}
}
#endregion
static class HashUtils
{
public static int CalcHashCodeEnumerable<T> (IEnumerable<T> list) where T : class
{
HashCode hashCode = new HashCode ();
foreach (var item in list)
hashCode.Add (item);
return hashCode.ToHashCode ();
}
}
}
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