.NET Decompiler with support for PDB generation, ReadyToRun, Metadata (&more) - cross-platform!
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// Copyright (c) 2014 Daniel Grunwald
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using ICSharpCode.Decompiler.CSharp.Transforms;
using ICSharpCode.Decompiler.IL;
using ICSharpCode.NRefactory;
using ICSharpCode.NRefactory.CSharp;
using ICSharpCode.NRefactory.CSharp.Refactoring;
using ICSharpCode.NRefactory.CSharp.Resolver;
using ICSharpCode.NRefactory.CSharp.TypeSystem;
using ICSharpCode.NRefactory.Semantics;
using ICSharpCode.NRefactory.TypeSystem;
using ExpressionType = System.Linq.Expressions.ExpressionType;
namespace ICSharpCode.Decompiler.CSharp
{
/// <summary>
/// Translates from ILAst to C# expressions.
/// </summary>
/// <remarks>
/// Every translated expression must have:
/// * an ILInstruction annotation
/// * a ResolveResult annotation
/// Post-condition for Translate() calls:
/// * The type of the ResolveResult must match the StackType of the corresponding ILInstruction,
/// except that the width of integer types does not need to match (I4, I and I8 count as the same stack type here)
/// * Evaluating the resulting C# expression shall produce the same side effects as evaluating the ILInstruction.
/// * If the IL instruction has <c>ResultType == StackType.Void</c>, the C# expression may evaluate to an arbitrary type and value.
/// * Otherwise, evaluating the resulting C# expression shall produce a similar value as evaluating the ILInstruction.
/// * If the IL instruction evaluates to an integer stack type (I4, I, or I8),
/// the C# type of the resulting expression shall also be an integer (or enum/pointer/char/bool) type.
/// * If sizeof(C# type) == sizeof(IL stack type), the values must be the same.
/// * If sizeof(C# type) > sizeof(IL stack type), the C# value truncated to the width of the IL stack type must equal the IL value.
/// * If sizeof(C# type) &lt; sizeof(IL stack type), the C# value (sign/zero-)extended to the width of the IL stack type
/// must equal the IL value.
/// Whether sign or zero extension is used depends on the sign of the C# type (as determined by <c>IType.GetSign()</c>).
/// * If the IL instruction evaluates to a non-integer type, the C# type of the resulting expression shall match the IL stack type,
/// and the evaluated values shall be the same.
/// </remarks>
class ExpressionBuilder : ILVisitor<TranslatedExpression>
{
internal readonly ICompilation compilation;
internal readonly CSharpResolver resolver;
readonly TypeSystemAstBuilder astBuilder;
public ExpressionBuilder(ITypeResolveContext decompilationContext)
{
Debug.Assert(decompilationContext != null);
this.compilation = decompilationContext.Compilation;
this.resolver = new CSharpResolver(new CSharpTypeResolveContext(compilation.MainAssembly, null, decompilationContext.CurrentTypeDefinition, decompilationContext.CurrentMember));
this.astBuilder = new TypeSystemAstBuilder(resolver);
this.astBuilder.AlwaysUseShortTypeNames = true;
this.astBuilder.AddResolveResultAnnotations = true;
}
public AstType ConvertType(IType type)
{
var astType = astBuilder.ConvertType(type);
Debug.Assert(astType.Annotation<TypeResolveResult>() != null);
return astType;
}
public ExpressionWithResolveResult ConvertConstantValue(ResolveResult rr)
{
var expr = astBuilder.ConvertConstantValue(rr);
var pe = expr as PrimitiveExpression;
if (pe != null) {
if (pe.Value is sbyte)
expr = expr.CastTo(new NRefactory.CSharp.PrimitiveType("sbyte"));
else if (pe.Value is byte)
expr = expr.CastTo(new NRefactory.CSharp.PrimitiveType("byte"));
else if (pe.Value is short)
expr = expr.CastTo(new NRefactory.CSharp.PrimitiveType("short"));
else if (pe.Value is ushort)
expr = expr.CastTo(new NRefactory.CSharp.PrimitiveType("ushort"));
}
var exprRR = expr.Annotation<ResolveResult>();
if (exprRR == null) {
exprRR = rr;
expr.AddAnnotation(rr);
}
return new ExpressionWithResolveResult(expr, exprRR);
}
public TranslatedExpression Translate(ILInstruction inst)
{
Debug.Assert(inst != null);
var cexpr = inst.AcceptVisitor(this);
#if DEBUG
if (inst.ResultType != StackType.Void && cexpr.Type.Kind != TypeKind.Unknown) {
if (inst.ResultType.IsIntegerType()) {
Debug.Assert(cexpr.Type.GetStackType().IsIntegerType(), "IL instructions of integer type must convert into C# expressions of integer type");
Debug.Assert(cexpr.Type.GetSign() != Sign.None, "Must have a sign specified for zero/sign-extension");
} else {
Debug.Assert(cexpr.Type.GetStackType() == inst.ResultType);
}
}
#endif
return cexpr;
}
public TranslatedExpression TranslateCondition(ILInstruction condition)
{
var expr = Translate(condition);
return expr.ConvertToBoolean(this);
}
ExpressionWithResolveResult ConvertVariable(ILVariable variable)
{
Expression expr;
if (variable.Kind == VariableKind.Parameter && variable.Index < 0)
expr = new ThisReferenceExpression();
else
expr = new IdentifierExpression(variable.Name);
if (variable.Type.Kind == TypeKind.ByReference) {
// When loading a by-ref parameter, use 'ref paramName'.
// We'll strip away the 'ref' when dereferencing.
// Ensure that the IdentifierExpression itself also gets a resolve result, as that might
// get used after the 'ref' is stripped away:
var elementType = ((ByReferenceType)variable.Type).ElementType;
expr.WithRR(new ILVariableResolveResult(variable, elementType));
expr = new DirectionExpression(FieldDirection.Ref, expr);
return expr.WithRR(new ResolveResult(variable.Type));
} else {
return expr.WithRR(new ILVariableResolveResult(variable, variable.Type));
}
}
ExpressionWithResolveResult ConvertField(IField field, ILInstruction target = null)
{
var lookup = new MemberLookup(resolver.CurrentTypeDefinition, resolver.CurrentTypeDefinition.ParentAssembly);
var targetExpression = TranslateTarget(field, target, true);
var result = lookup.Lookup(targetExpression.ResolveResult, field.Name, EmptyList<IType>.Instance, false) as MemberResolveResult;
if (result == null || !result.Member.Equals(field))
targetExpression = targetExpression.ConvertTo(field.DeclaringType, this);
return new MemberReferenceExpression(targetExpression, field.Name)
.WithRR(new MemberResolveResult(targetExpression.ResolveResult, field));
}
TranslatedExpression IsType(IsInst inst)
{
var arg = Translate(inst.Argument);
return new IsExpression(arg.Expression, ConvertType(inst.Type))
.WithILInstruction(inst)
.WithRR(new TypeIsResolveResult(arg.ResolveResult, inst.Type, compilation.FindType(TypeCode.Boolean)));
}
protected internal override TranslatedExpression VisitIsInst(IsInst inst)
{
var arg = Translate(inst.Argument);
return new AsExpression(arg.Expression, ConvertType(inst.Type))
.WithILInstruction(inst)
.WithRR(new ConversionResolveResult(inst.Type, arg.ResolveResult, Conversion.TryCast));
}
protected internal override TranslatedExpression VisitNewObj(NewObj inst)
{
return HandleCallInstruction(inst);
}
protected internal override TranslatedExpression VisitNewArr(NewArr inst)
{
var dimensions = inst.Indices.Count;
var args = inst.Indices.Select(arg => TranslateArrayIndex(arg)).ToArray();
var expr = new ArrayCreateExpression { Type = ConvertType(inst.Type) };
var ct = expr.Type as ComposedType;
if (ct != null) {
// change "new (int[,])[10] to new int[10][,]"
ct.ArraySpecifiers.MoveTo(expr.AdditionalArraySpecifiers);
}
expr.Arguments.AddRange(args.Select(arg => arg.Expression));
return expr.WithILInstruction(inst)
.WithRR(new ArrayCreateResolveResult(new ArrayType(compilation, inst.Type, dimensions), args.Select(a => a.ResolveResult).ToList(), new ResolveResult[0]));
}
protected internal override TranslatedExpression VisitLocAlloc(LocAlloc inst)
{
var byteType = compilation.FindType(KnownTypeCode.Byte);
return new StackAllocExpression {
Type = ConvertType(byteType),
CountExpression = Translate(inst.Argument)
}.WithILInstruction(inst).WithRR(new ResolveResult(new PointerType(byteType)));
}
protected internal override TranslatedExpression VisitLdcI4(LdcI4 inst)
{
return new PrimitiveExpression(inst.Value)
.WithILInstruction(inst)
.WithRR(new ConstantResolveResult(compilation.FindType(KnownTypeCode.Int32), inst.Value));
}
protected internal override TranslatedExpression VisitLdcI8(LdcI8 inst)
{
return new PrimitiveExpression(inst.Value)
.WithILInstruction(inst)
.WithRR(new ConstantResolveResult(compilation.FindType(KnownTypeCode.Int64), inst.Value));
}
protected internal override TranslatedExpression VisitLdcF(LdcF inst)
{
return new PrimitiveExpression(inst.Value)
.WithILInstruction(inst)
.WithRR(new ConstantResolveResult(compilation.FindType(KnownTypeCode.Double), inst.Value));
}
protected internal override TranslatedExpression VisitLdcDecimal(LdcDecimal inst)
{
return new PrimitiveExpression(inst.Value)
.WithILInstruction(inst)
.WithRR(new ConstantResolveResult(compilation.FindType(KnownTypeCode.Decimal), inst.Value));
}
protected internal override TranslatedExpression VisitLdStr(LdStr inst)
{
return new PrimitiveExpression(inst.Value)
.WithILInstruction(inst)
.WithRR(new ConstantResolveResult(compilation.FindType(KnownTypeCode.String), inst.Value));
}
protected internal override TranslatedExpression VisitLdNull(LdNull inst)
{
return new NullReferenceExpression()
.WithILInstruction(inst)
.WithRR(new ConstantResolveResult(SpecialType.NullType, null));
}
protected internal override TranslatedExpression VisitDefaultValue(DefaultValue inst)
{
return new DefaultValueExpression(ConvertType(inst.Type))
.WithILInstruction(inst)
.WithRR(new ConstantResolveResult(inst.Type, null));
}
protected internal override TranslatedExpression VisitSizeOf(SizeOf inst)
{
return new SizeOfExpression(ConvertType(inst.Type))
.WithILInstruction(inst)
.WithRR(new SizeOfResolveResult(compilation.FindType(KnownTypeCode.Int32), inst.Type, null));
}
protected internal override TranslatedExpression VisitLdTypeToken(LdTypeToken inst)
{
return new TypeOfExpression(ConvertType(inst.Type)).Member("TypeHandle")
.WithILInstruction(inst)
.WithRR(new TypeOfResolveResult(compilation.FindType(new TopLevelTypeName("System", "RuntimeTypeHandle")), inst.Type));
}
protected internal override TranslatedExpression VisitLogicNot(LogicNot inst)
{
return LogicNot(TranslateCondition(inst.Argument)).WithILInstruction(inst);
}
protected internal override TranslatedExpression VisitBitNot(BitNot inst)
{
var argument = Translate(inst.Argument);
var compatibleType = argument.Type.GetEnumUnderlyingType();
var type = compatibleType.GetDefinition();
if (type != null) {
switch (type.KnownTypeCode) {
case KnownTypeCode.Boolean:
case KnownTypeCode.Char:
compatibleType = compilation.FindType(KnownTypeCode.UInt32);
break;
case KnownTypeCode.IntPtr:
compatibleType = compilation.FindType(KnownTypeCode.Int64);
break;
case KnownTypeCode.UIntPtr:
compatibleType = compilation.FindType(KnownTypeCode.UInt64);
break;
}
}
argument = argument.ConvertTo(compatibleType, this);
var rr = resolver.ResolveUnaryOperator(UnaryOperatorType.BitNot, argument.ResolveResult);
var result = new UnaryOperatorExpression(UnaryOperatorType.BitNot, argument)
.WithRR(rr)
.WithILInstruction(inst);
if (type != null && (type.KnownTypeCode == KnownTypeCode.IntPtr || type.KnownTypeCode == KnownTypeCode.UIntPtr)) {
return result.ConvertTo(type, this);
} else {
return result;
}
}
ExpressionWithResolveResult LogicNot(TranslatedExpression expr)
{
return new UnaryOperatorExpression(UnaryOperatorType.Not, expr.Expression)
.WithRR(new OperatorResolveResult(compilation.FindType(KnownTypeCode.Boolean), ExpressionType.Not, expr.ResolveResult));
}
readonly HashSet<ILVariable> loadedVariablesSet = new HashSet<ILVariable>();
protected internal override TranslatedExpression VisitLdLoc(LdLoc inst)
{
if (inst.Variable.Kind == VariableKind.StackSlot && inst.Variable.IsSingleDefinition) {
loadedVariablesSet.Add(inst.Variable);
}
return ConvertVariable(inst.Variable).WithILInstruction(inst);
}
protected internal override TranslatedExpression VisitLdLoca(LdLoca inst)
{
var expr = ConvertVariable(inst.Variable).WithILInstruction(inst);
// Note that we put the instruction on the IdentifierExpression instead of the DirectionExpression,
// because the DirectionExpression might get removed by dereferencing instructions such as LdObj
return new DirectionExpression(FieldDirection.Ref, expr.Expression)
.WithoutILInstruction()
.WithRR(new ByReferenceResolveResult(expr.ResolveResult, isOut: false));
}
protected internal override TranslatedExpression VisitStLoc(StLoc inst)
{
var translatedValue = Translate(inst.Value);
if (inst.Variable.Kind == VariableKind.StackSlot && inst.Variable.IsSingleDefinition
&& inst.Variable.StackType == translatedValue.Type.GetStackType()
&& translatedValue.Type.Kind != TypeKind.Null && !loadedVariablesSet.Contains(inst.Variable)) {
inst.Variable.Type = translatedValue.Type;
}
return Assignment(ConvertVariable(inst.Variable).WithoutILInstruction(), translatedValue).WithILInstruction(inst);
}
protected internal override TranslatedExpression VisitComp(Comp inst)
{
if (inst.Kind.IsEqualityOrInequality()) {
bool negateOutput;
var result = TranslateCeq(inst, out negateOutput);
if (negateOutput)
return LogicNot(result).WithILInstruction(inst);
else
return result;
} else {
return TranslateComp(inst);
}
}
/// <summary>
/// Translates the equality comparison between left and right.
/// </summary>
TranslatedExpression TranslateCeq(Comp inst, out bool negateOutput)
{
// Translate '(e as T) == null' to '!(e is T)'.
// This is necessary for correctness when T is a value type.
if (inst.Left.OpCode == OpCode.IsInst && inst.Right.OpCode == OpCode.LdNull) {
negateOutput = inst.Kind == ComparisonKind.Equality;
return IsType((IsInst)inst.Left);
} else if (inst.Right.OpCode == OpCode.IsInst && inst.Left.OpCode == OpCode.LdNull) {
negateOutput = inst.Kind == ComparisonKind.Equality;
return IsType((IsInst)inst.Right);
}
var left = Translate(inst.Left);
var right = Translate(inst.Right);
// Remove redundant bool comparisons
if (left.Type.IsKnownType(KnownTypeCode.Boolean)) {
if (inst.Right.MatchLdcI4(0)) {
// 'b == 0' => '!b'
// 'b != 0' => 'b'
negateOutput = inst.Kind == ComparisonKind.Equality;
return left;
}
if (inst.Right.MatchLdcI4(1)) {
// 'b == 1' => 'b'
// 'b != 1' => '!b'
negateOutput = inst.Kind == ComparisonKind.Inequality;
return left;
}
} else if (right.Type.IsKnownType(KnownTypeCode.Boolean)) {
if (inst.Left.MatchLdcI4(0)) {
// '0 == b' => '!b'
// '0 != b' => 'b'
negateOutput = inst.Kind == ComparisonKind.Equality;
return right;
}
if (inst.Left.MatchLdcI4(1)) {
// '0 == b' => '!b'
// '0 != b' => 'b'
negateOutput = inst.Kind == ComparisonKind.Equality;
return right;
}
}
var rr = resolver.ResolveBinaryOperator(inst.Kind.ToBinaryOperatorType(), left.ResolveResult, right.ResolveResult)
as OperatorResolveResult;
if (rr == null || rr.IsError || rr.UserDefinedOperatorMethod != null
|| rr.Operands[0].Type.GetStackType() != inst.InputType)
{
var targetType = TypeUtils.GetLargerType(left.Type, right.Type);
if (targetType.Equals(left.Type)) {
right = right.ConvertTo(targetType, this);
} else {
left = left.ConvertTo(targetType, this);
}
rr = new OperatorResolveResult(compilation.FindType(KnownTypeCode.Boolean),
BinaryOperatorExpression.GetLinqNodeType(BinaryOperatorType.Equality, false),
left.ResolveResult, right.ResolveResult);
}
negateOutput = false;
return new BinaryOperatorExpression(left.Expression, inst.Kind.ToBinaryOperatorType(), right.Expression)
.WithILInstruction(inst)
.WithRR(rr);
}
/// <summary>
/// Handle Comp instruction, operators other than equality/inequality.
/// </summary>
TranslatedExpression TranslateComp(Comp inst)
{
var left = Translate(inst.Left);
var right = Translate(inst.Right);
// Ensure the inputs have the correct sign:
KnownTypeCode inputType = KnownTypeCode.None;
switch (inst.InputType) {
case StackType.I: // In order to generate valid C# we need to treat (U)IntPtr as (U)Int64 in comparisons.
case StackType.I8:
inputType = inst.Sign == Sign.Unsigned ? KnownTypeCode.UInt64 : KnownTypeCode.Int64;
break;
case StackType.I4:
inputType = inst.Sign == Sign.Unsigned ? KnownTypeCode.UInt32 : KnownTypeCode.Int32;
break;
}
if (inputType != KnownTypeCode.None) {
left = left.ConvertTo(compilation.FindType(inputType), this);
right = right.ConvertTo(compilation.FindType(inputType), this);
}
var op = inst.Kind.ToBinaryOperatorType();
return new BinaryOperatorExpression(left.Expression, op, right.Expression)
.WithILInstruction(inst)
.WithRR(new OperatorResolveResult(compilation.FindType(TypeCode.Boolean),
BinaryOperatorExpression.GetLinqNodeType(op, false),
left.ResolveResult, right.ResolveResult));
}
ExpressionWithResolveResult Assignment(TranslatedExpression left, TranslatedExpression right)
{
right = right.ConvertTo(left.Type, this);
return new AssignmentExpression(left.Expression, right.Expression)
.WithRR(new OperatorResolveResult(left.Type, ExpressionType.Assign, left.ResolveResult, right.ResolveResult));
}
protected internal override TranslatedExpression VisitAdd(Add inst)
{
return HandleBinaryNumeric(inst, BinaryOperatorType.Add);
}
protected internal override TranslatedExpression VisitSub(Sub inst)
{
return HandleBinaryNumeric(inst, BinaryOperatorType.Subtract);
}
protected internal override TranslatedExpression VisitMul(Mul inst)
{
return HandleBinaryNumeric(inst, BinaryOperatorType.Multiply);
}
protected internal override TranslatedExpression VisitDiv(Div inst)
{
return HandleBinaryNumeric(inst, BinaryOperatorType.Divide);
}
protected internal override TranslatedExpression VisitRem(Rem inst)
{
return HandleBinaryNumeric(inst, BinaryOperatorType.Modulus);
}
protected internal override TranslatedExpression VisitBitXor(BitXor inst)
{
return HandleBinaryNumeric(inst, BinaryOperatorType.ExclusiveOr);
}
protected internal override TranslatedExpression VisitBitAnd(BitAnd inst)
{
return HandleBinaryNumeric(inst, BinaryOperatorType.BitwiseAnd);
}
protected internal override TranslatedExpression VisitBitOr(BitOr inst)
{
return HandleBinaryNumeric(inst, BinaryOperatorType.BitwiseOr);
}
TranslatedExpression HandleBinaryNumeric(BinaryNumericInstruction inst, BinaryOperatorType op)
{
var resolverWithOverflowCheck = resolver.WithCheckForOverflow(inst.CheckForOverflow);
var left = Translate(inst.Left);
var right = Translate(inst.Right);
ResolveResult rr;
if (left.Type.GetStackType() == StackType.I || right.Type.GetStackType() == StackType.I) {
// IntPtr or pointers as input.
// C# doesn't allow adding IntPtr values, and adding pointer values has the wrong semantics
// (adding number of elements instead of number of bytes), so switch to long/ulong in both cases.
IType targetType;
if (inst.Sign == Sign.Unsigned) {
targetType = compilation.FindType(KnownTypeCode.UInt64);
} else {
targetType = compilation.FindType(KnownTypeCode.Int64);
}
left = left.ConvertTo(targetType, this);
right = right.ConvertTo(targetType, this);
rr = new OperatorResolveResult(targetType, BinaryOperatorExpression.GetLinqNodeType(op, inst.CheckForOverflow), left.ResolveResult, right.ResolveResult);
var resultExpr = new BinaryOperatorExpression(left.Expression, op, right.Expression)
.WithILInstruction(inst)
.WithRR(rr);
if (BinaryOperatorMightCheckForOverflow(op))
resultExpr.Expression.AddAnnotation(inst.CheckForOverflow ? AddCheckedBlocks.CheckedAnnotation : AddCheckedBlocks.UncheckedAnnotation);
return resultExpr.ConvertTo(compilation.FindType(inst.ResultType.ToKnownTypeCode()), this);
} else {
rr = resolverWithOverflowCheck.ResolveBinaryOperator(op, left.ResolveResult, right.ResolveResult);
if (rr.IsError || rr.Type.GetStackType() != inst.ResultType
|| !IsCompatibleWithSign(left.Type, inst.Sign) || !IsCompatibleWithSign(right.Type, inst.Sign))
{
// Left and right operands are incompatible, so convert them to a common type
IType targetType = compilation.FindType(inst.ResultType.ToKnownTypeCode(inst.Sign));
left = left.ConvertTo(targetType, this);
right = right.ConvertTo(targetType, this);
rr = resolverWithOverflowCheck.ResolveBinaryOperator(op, left.ResolveResult, right.ResolveResult);
}
var resultExpr = new BinaryOperatorExpression(left.Expression, op, right.Expression)
.WithILInstruction(inst)
.WithRR(rr);
if (BinaryOperatorMightCheckForOverflow(op))
resultExpr.Expression.AddAnnotation(inst.CheckForOverflow ? AddCheckedBlocks.CheckedAnnotation : AddCheckedBlocks.UncheckedAnnotation);
return resultExpr;
}
}
static bool BinaryOperatorMightCheckForOverflow(BinaryOperatorType op)
{
switch (op) {
case BinaryOperatorType.BitwiseAnd:
case BinaryOperatorType.BitwiseOr:
case BinaryOperatorType.ExclusiveOr:
case BinaryOperatorType.ShiftLeft:
case BinaryOperatorType.ShiftRight:
return false;
default:
return true;
}
}
/// <summary>
/// Gets whether <paramref name="type"/> has the specified <paramref name="sign"/>.
/// If <paramref name="sign"/> is None, always returns true.
/// </summary>
bool IsCompatibleWithSign(IType type, Sign sign)
{
return sign == Sign.None || type.GetSign() == sign;
}
protected internal override TranslatedExpression VisitShl(Shl inst)
{
return HandleShift(inst, BinaryOperatorType.ShiftLeft);
}
protected internal override TranslatedExpression VisitShr(Shr inst)
{
return HandleShift(inst, BinaryOperatorType.ShiftRight);
}
TranslatedExpression HandleShift(BinaryNumericInstruction inst, BinaryOperatorType op)
{
var left = Translate(inst.Left);
var right = Translate(inst.Right);
IType targetType;
if (inst.ResultType == StackType.I4)
targetType = compilation.FindType(inst.Sign == Sign.Unsigned ? KnownTypeCode.UInt32 : KnownTypeCode.Int32);
else
targetType = compilation.FindType(inst.Sign == Sign.Unsigned ? KnownTypeCode.UInt64 : KnownTypeCode.Int64);
left = left.ConvertTo(targetType, this);
// Shift operators in C# always expect type 'int' on the right-hand-side
right = right.ConvertTo(compilation.FindType(KnownTypeCode.Int32), this);
TranslatedExpression result = new BinaryOperatorExpression(left.Expression, op, right.Expression)
.WithILInstruction(inst)
.WithRR(resolver.ResolveBinaryOperator(op, left.ResolveResult, right.ResolveResult));
if (inst.ResultType == StackType.I) {
// C# doesn't have shift operators for IntPtr, so we first shifted a long/ulong,
// and now have to case back down to IntPtr/UIntPtr:
result = result.ConvertTo(compilation.FindType(inst.Sign == Sign.Unsigned ? KnownTypeCode.UIntPtr : KnownTypeCode.IntPtr), this);
}
return result;
}
protected internal override TranslatedExpression VisitConv(Conv inst)
{
var arg = Translate(inst.Argument);
StackType inputStackType = inst.Argument.ResultType;
// Note: we're dealing with two conversions here:
// a) the implicit conversion from `arg.Type` to `inputStackType`
// (due to the ExpressionBuilder post-condition being flexible with regards to the integer type width)
// If this is a widening conversion, I'm calling the argument C# type "oversized".
// If this is a narrowing conversion, I'm calling the argument C# type "undersized".
// b) the actual conversion instruction from `inputStackType` to `inst.TargetType`
// Also, we need to be very careful with regards to the conversions we emit:
// In C#, zero vs. sign-extension depends on the input type,
// but in the ILAst conv instruction it depends on the output type.
// However, in the conv.ovf instructions, the .NET runtime behavior seems to depend on the input type,
// in violation of the ECMA-335 spec!
if (inst.CheckForOverflow || inst.Kind == ConversionKind.IntToFloat) {
// We need to first convert the argument to the expected sign.
// We also need to perform any input narrowing conversion so that it doesn't get mixed up with the overflow check.
Debug.Assert(inst.InputSign != Sign.None);
if (arg.Type.GetSize() > inputStackType.GetSize() || arg.Type.GetSign() != inst.InputSign) {
arg = arg.ConvertTo(compilation.FindType(inputStackType.ToKnownTypeCode(inst.InputSign)), this);
}
// Because casts with overflow check match C# semantics (zero/sign-extension depends on source type),
// we can just directly cast to the target type.
return arg.ConvertTo(compilation.FindType(inst.TargetType.ToKnownTypeCode()), this, true)
.WithILInstruction(inst);
}
switch (inst.Kind) {
case ConversionKind.StopGCTracking:
if (arg.Type.Kind == TypeKind.ByReference) {
// cast to corresponding pointer type:
var pointerType = new PointerType(((ByReferenceType)arg.Type).ElementType);
return arg.ConvertTo(pointerType, this).WithILInstruction(inst);
} else {
Debug.Fail("ConversionKind.StopGCTracking should only be used with managed references");
goto default;
}
case ConversionKind.SignExtend:
// We just need to ensure the input type before the conversion is signed.
// Also, if the argument was translated into an oversized C# type,
// we need to perform the truncatation to the input stack type.
if (arg.Type.GetSign() != Sign.Signed || arg.Type.GetSize() > inputStackType.GetSize()) {
// Note that an undersized C# type is handled just fine:
// If it is unsigned we'll zero-extend it to the width of the inputStackType here,
// and it is signed we just combine the two sign-extensions into a single sign-extending conversion.
arg = arg.ConvertTo(compilation.FindType(inputStackType.ToKnownTypeCode(Sign.Signed)), this);
}
// Then, we can just return the argument as-is: the ExpressionBuilder post-condition allows us
// to force our parent instruction to handle the actual sign-extension conversion.
// (our caller may have more information to pick a better fitting target type)
return arg.WithILInstruction(inst);
case ConversionKind.ZeroExtend:
// If overflow check cannot fail, handle this just like sign extension (except for swapped signs)
if (arg.Type.GetSign() != Sign.Unsigned || arg.Type.GetSize() > inputStackType.GetSize()) {
arg = arg.ConvertTo(compilation.FindType(inputStackType.ToKnownTypeCode(Sign.Unsigned)), this);
}
return arg.WithILInstruction(inst);
case ConversionKind.Nop:
// no need to generate any C# code for a nop conversion
return arg.WithILInstruction(inst);
case ConversionKind.Truncate:
// Note: there are three sizes involved here:
// A = arg.Type.GetSize()
// B = inputStackType.GetSize()
// C = inst.TargetType.GetSize().
// We know that C <= B (otherwise this wouldn't be the truncation case).
// 1) If C < B < A, we just combine the two truncations into one.
// 2) If C < B = A, there's no input conversion, just the truncation
// 3) If C <= A < B, all the extended bits get removed again by the truncation.
// 4) If A < C < B, some extended bits remain even after truncation.
// In cases 1-3, the overall conversion is a truncation or no-op.
// In case 4, the overall conversion is a zero/sign extension, but to a smaller
// size than the original conversion.
if (inst.TargetType.IsSmallIntegerType()) {
// If the target type is a small integer type, IL will implicitly sign- or zero-extend
// the result after the truncation back to StackType.I4.
// (which means there's actually 3 conversions involved!)
if (arg.Type.GetSize() <= inst.TargetType.GetSize() && arg.Type.GetSign() == inst.TargetType.GetSign()) {
// There's no actual truncation involved, and the result of the Conv instruction is extended
// the same way as the original instruction
// -> we can return arg directly
return arg.WithILInstruction(inst);
} else {
// We need to actually truncate; *or* we need to change the sign for the remaining extension to I4.
goto default; // Emit simple cast to inst.TargetType
}
} else {
Debug.Assert(inst.TargetType.GetSize() == inst.ResultType.GetSize());
// For non-small integer types, we can let the whole unchecked truncation
// get handled by our caller (using the ExpressionBuilder post-condition).
// Case 4 (left-over extension from implicit conversion) can also be handled by our caller.
return arg.WithILInstruction(inst);
}
default:
return arg.ConvertTo(compilation.FindType(inst.TargetType.ToKnownTypeCode()), this, inst.CheckForOverflow)
.WithILInstruction(inst);
}
}
protected internal override TranslatedExpression VisitCall(Call inst)
{
return HandleCallInstruction(inst);
}
protected internal override TranslatedExpression VisitCallVirt(CallVirt inst)
{
return HandleCallInstruction(inst);
}
static bool IsDelegateConstruction(CallInstruction inst)
{
return inst.Arguments.Count == 2
&& (inst.Arguments[1].OpCode == OpCode.LdFtn
|| inst.Arguments[1].OpCode == OpCode.LdVirtFtn)
&& inst.Method.DeclaringType.Kind == TypeKind.Delegate;
}
TranslatedExpression HandleDelegateConstruction(CallInstruction inst)
{
ILInstruction func = inst.Arguments[1];
IMethod method;
if (func.OpCode == OpCode.LdFtn) {
method = ((LdFtn)func).Method;
} else {
method = ((LdVirtFtn)func).Method;
}
var target = TranslateTarget(method, inst.Arguments[0], func.OpCode == OpCode.LdFtn);
var lookup = new MemberLookup(resolver.CurrentTypeDefinition, resolver.CurrentTypeDefinition.ParentAssembly);
var or = new OverloadResolution(resolver.Compilation, method.Parameters.SelectArray(p => new TypeResolveResult(p.Type)));
var result = lookup.Lookup(target.ResolveResult, method.Name, method.TypeArguments, true) as MethodGroupResolveResult;
if (result == null) {
target = target.ConvertTo(method.DeclaringType, this);
} else {
or.AddMethodLists(result.MethodsGroupedByDeclaringType.ToArray());
if (or.BestCandidateErrors != OverloadResolutionErrors.None || !IsAppropriateCallTarget(method, or.BestCandidate, func.OpCode == OpCode.LdVirtFtn))
target = target.ConvertTo(method.DeclaringType, this);
}
var mre = new MemberReferenceExpression(target, method.Name);
mre.TypeArguments.AddRange(method.TypeArguments.Select(a => ConvertType(a)));
return new ObjectCreateExpression(ConvertType(inst.Method.DeclaringType), mre)
.WithILInstruction(inst)
.WithRR(new ConversionResolveResult(
inst.Method.DeclaringType,
new MemberResolveResult(target.ResolveResult, method),
// TODO handle extension methods capturing the first argument
Conversion.MethodGroupConversion(method, func.OpCode == OpCode.LdVirtFtn, false)));
}
TranslatedExpression TranslateTarget(IMember member, ILInstruction target, bool nonVirtualInvocation)
{
if (!member.IsStatic) {
if (nonVirtualInvocation && target.MatchLdThis() && member.DeclaringTypeDefinition != resolver.CurrentTypeDefinition) {
return new BaseReferenceExpression()
.WithILInstruction(target)
.WithRR(new ThisResolveResult(member.DeclaringType, nonVirtualInvocation));
} else {
var translatedTarget = Translate(target);
if (translatedTarget.Expression is DirectionExpression) {
translatedTarget = translatedTarget.UnwrapChild(((DirectionExpression)translatedTarget).Expression);
}
return translatedTarget;
}
} else {
return new TypeReferenceExpression(ConvertType(member.DeclaringType))
.WithoutILInstruction()
.WithRR(new TypeResolveResult(member.DeclaringType));
}
}
TranslatedExpression HandleCallInstruction(CallInstruction inst)
{
IMethod method = inst.Method;
// Used for Call, CallVirt and NewObj
TranslatedExpression target;
if (inst.OpCode == OpCode.NewObj) {
if (IsDelegateConstruction(inst)) {
return HandleDelegateConstruction(inst);
}
target = default(TranslatedExpression); // no target
} else {
target = TranslateTarget(method, inst.Arguments.FirstOrDefault(), inst.OpCode == OpCode.Call);
}
var arguments = inst.Arguments.SelectArray(Translate);
int firstParamIndex = (method.IsStatic || inst.OpCode == OpCode.NewObj) ? 0 : 1;
// Translate arguments to the expected parameter types
Debug.Assert(arguments.Length == firstParamIndex + inst.Method.Parameters.Count);
for (int i = firstParamIndex; i < arguments.Length; i++) {
var parameter = method.Parameters[i - firstParamIndex];
arguments[i] = arguments[i].ConvertTo(parameter.Type, this);
if (parameter.IsOut && arguments[i].Expression is DirectionExpression) {
((DirectionExpression)arguments[i].Expression).FieldDirection = FieldDirection.Out;
}
}
if (method is VarArgInstanceMethod) {
int regularParameterCount = ((VarArgInstanceMethod)method).RegularParameterCount;
var argListArg = new UndocumentedExpression();
argListArg.UndocumentedExpressionType = UndocumentedExpressionType.ArgList;
argListArg.Arguments.AddRange(arguments.Skip(regularParameterCount).Select(arg => arg.Expression));
var argListRR = new ResolveResult(SpecialType.ArgList);
arguments = arguments.Take(regularParameterCount)
.Concat(new[] { argListArg.WithoutILInstruction().WithRR(argListRR) }).ToArray();
method = (IMethod)method.MemberDefinition;
}
var argumentResolveResults = arguments.Skip(firstParamIndex).Select(arg => arg.ResolveResult).ToList();
ResolveResult rr;
if (inst.Method.IsAccessor)
rr = new MemberResolveResult(target.ResolveResult, method.AccessorOwner);
else
rr = new CSharpInvocationResolveResult(target.ResolveResult, method, argumentResolveResults);
if (inst.OpCode == OpCode.NewObj) {
var argumentExpressions = arguments.Skip(firstParamIndex).Select(arg => arg.Expression).ToList();
return new ObjectCreateExpression(ConvertType(inst.Method.DeclaringType), argumentExpressions)
.WithILInstruction(inst).WithRR(rr);
} else {
Expression expr;
int allowedParamCount = (method.ReturnType.IsKnownType(KnownTypeCode.Void) ? 1 : 0);
if (method.IsAccessor && (method.AccessorOwner.SymbolKind == SymbolKind.Indexer || method.Parameters.Count == allowedParamCount)) {
expr = HandleAccessorCall(inst, target, method, arguments.Skip(firstParamIndex).ToList());
} else {
var lookup = new MemberLookup(resolver.CurrentTypeDefinition, resolver.CurrentTypeDefinition.ParentAssembly);
var or = new OverloadResolution(resolver.Compilation, arguments.Skip(firstParamIndex).Select(a => a.ResolveResult).ToArray());
var result = lookup.Lookup(target.ResolveResult, method.Name, method.TypeArguments, true) as MethodGroupResolveResult;
if (result == null) {
target = target.ConvertTo(method.DeclaringType, this);
} else {
or.AddMethodLists(result.MethodsGroupedByDeclaringType.ToArray());
if (or.BestCandidateErrors != OverloadResolutionErrors.None || !IsAppropriateCallTarget(method, or.BestCandidate, inst.OpCode == OpCode.CallVirt))
target = target.ConvertTo(method.DeclaringType, this);
}
Expression targetExpr = target.Expression;
string methodName = method.Name;
// HACK : convert this.Dispose() to ((IDisposable)this).Dispose(), if Dispose is an explicitly implemented interface method.
if (inst.Method.IsExplicitInterfaceImplementation && targetExpr is ThisReferenceExpression) {
targetExpr = targetExpr.CastTo(ConvertType(method.ImplementedInterfaceMembers[0].DeclaringType));
methodName = method.ImplementedInterfaceMembers[0].Name;
}
var mre = new MemberReferenceExpression(targetExpr, methodName);
mre.TypeArguments.AddRange(method.TypeArguments.Select(a => ConvertType(a)));
var argumentExpressions = arguments.Skip(firstParamIndex).Select(arg => arg.Expression).ToList();
expr = new InvocationExpression(mre, argumentExpressions);
}
return expr.WithILInstruction(inst).WithRR(rr);
}
}
Expression HandleAccessorCall(ILInstruction inst, TranslatedExpression target, IMethod method, IList<TranslatedExpression> arguments)
{
var lookup = new MemberLookup(resolver.CurrentTypeDefinition, resolver.CurrentTypeDefinition.ParentAssembly);
var result = lookup.Lookup(target.ResolveResult, method.AccessorOwner.Name, EmptyList<IType>.Instance, isInvocation:false);
if (result.IsError || (result is MemberResolveResult && !IsAppropriateCallTarget(method.AccessorOwner, ((MemberResolveResult)result).Member, inst.OpCode == OpCode.CallVirt)))
target = target.ConvertTo(method.AccessorOwner.DeclaringType, this);
if (method.ReturnType.IsKnownType(KnownTypeCode.Void)) {
var value = arguments.Last();
arguments.Remove(value);
Expression expr;
if (arguments.Count == 0)
expr = new MemberReferenceExpression(target.Expression, method.AccessorOwner.Name);
else
expr = new IndexerExpression(target.Expression, arguments.Select(a => a.Expression));
var op = AssignmentOperatorType.Assign;
var parentEvent = method.AccessorOwner as IEvent;
if (parentEvent != null) {
if (method.Equals(parentEvent.AddAccessor)) {
op = AssignmentOperatorType.Add;
}
if (method.Equals(parentEvent.RemoveAccessor)) {
op = AssignmentOperatorType.Subtract;
}
}
return new AssignmentExpression(expr, op, value.Expression);
} else {
if (arguments.Count == 0)
return new MemberReferenceExpression(target.Expression, method.AccessorOwner.Name);
else
return new IndexerExpression(target.Expression, arguments.Select(a => a.Expression));
}
}
bool IsAppropriateCallTarget(IMember expectedTarget, IMember actualTarget, bool isVirtCall)
{
if (expectedTarget.Equals(actualTarget))
return true;
if (isVirtCall && actualTarget.IsOverride) {
foreach (var possibleTarget in InheritanceHelper.GetBaseMembers(actualTarget, false)) {
if (expectedTarget.Equals(possibleTarget))
return true;
if (!possibleTarget.IsOverride)
break;
}
}
return false;
}
protected internal override TranslatedExpression VisitLdObj(LdObj inst)
{
var target = Translate(inst.Target);
if (target.Expression is DirectionExpression && TypeUtils.IsCompatibleTypeForMemoryAccess(target.Type, inst.Type)) {
// we can dereference the managed reference by stripping away the 'ref'
var result = target.UnwrapChild(((DirectionExpression)target.Expression).Expression);
// we don't convert result to inst.Type, because the LdObj type
// might be inaccurate (it's often System.Object for all reference types),
// and our parent node should already insert casts where necessary
result.Expression.AddAnnotation(inst); // add LdObj in addition to the existing ILInstruction annotation
if (target.Type.IsSmallIntegerType() && inst.Type.IsSmallIntegerType() && target.Type.GetSign() != inst.Type.GetSign())
return result.ConvertTo(inst.Type, this);
return result;
} else {
// Cast pointer type if necessary:
target = target.ConvertTo(new PointerType(inst.Type), this);
return new UnaryOperatorExpression(UnaryOperatorType.Dereference, target.Expression)
.WithILInstruction(inst)
.WithRR(new ResolveResult(inst.Type));
}
}
protected internal override TranslatedExpression VisitStObj(StObj inst)
{
var target = Translate(inst.Target);
var value = Translate(inst.Value);
TranslatedExpression result;
if (target.Expression is DirectionExpression && TypeUtils.IsCompatibleTypeForMemoryAccess(target.Type, inst.Type)) {
// we can deference the managed reference by stripping away the 'ref'
result = target.UnwrapChild(((DirectionExpression)target.Expression).Expression);
} else {
// Cast pointer type if necessary:
target = target.ConvertTo(new PointerType(inst.Type), this);
result = new UnaryOperatorExpression(UnaryOperatorType.Dereference, target.Expression)
.WithoutILInstruction()
.WithRR(new ResolveResult(inst.Type));
}
return Assignment(result, value).WithILInstruction(inst);
}
protected internal override TranslatedExpression VisitLdFld(LdFld inst)
{
return ConvertField(inst.Field, inst.Target).WithILInstruction(inst);
}
protected internal override TranslatedExpression VisitStFld(StFld inst)
{
return Assignment(ConvertField(inst.Field, inst.Target).WithoutILInstruction(), Translate(inst.Value)).WithILInstruction(inst);
}
protected internal override TranslatedExpression VisitLdsFld(LdsFld inst)
{
return ConvertField(inst.Field).WithILInstruction(inst);
}
protected internal override TranslatedExpression VisitStsFld(StsFld inst)
{
return Assignment(ConvertField(inst.Field).WithoutILInstruction(), Translate(inst.Value)).WithILInstruction(inst);
}
protected internal override TranslatedExpression VisitLdLen(LdLen inst)
{
TranslatedExpression arrayExpr = Translate(inst.Array);
if (arrayExpr.Type.Kind != TypeKind.Array) {
arrayExpr = arrayExpr.ConvertTo(compilation.FindType(KnownTypeCode.Array), this);
}
TranslatedExpression lenExpr;
if (inst.ResultType == StackType.I4) {
lenExpr = arrayExpr.Expression.Member("Length")
.WithILInstruction(inst)
.WithRR(new ResolveResult(compilation.FindType(KnownTypeCode.Int32)));
} else {
lenExpr = arrayExpr.Expression.Member("LongLength")
.WithILInstruction(inst)
.WithRR(new ResolveResult(compilation.FindType(KnownTypeCode.Int64)));
}
return lenExpr.ConvertTo(compilation.FindType(inst.ResultType.ToKnownTypeCode()), this);
}
protected internal override TranslatedExpression VisitLdFlda(LdFlda inst)
{
var expr = ConvertField(inst.Field, inst.Target);
return new DirectionExpression(FieldDirection.Ref, expr)
.WithoutILInstruction().WithRR(new ResolveResult(new ByReferenceType(expr.Type)));
}
protected internal override TranslatedExpression VisitLdsFlda(LdsFlda inst)
{
var expr = ConvertField(inst.Field);
return new DirectionExpression(FieldDirection.Ref, expr)
.WithoutILInstruction().WithRR(new ResolveResult(new ByReferenceType(expr.Type)));
}
protected internal override TranslatedExpression VisitLdElema(LdElema inst)
{
TranslatedExpression arrayExpr = Translate(inst.Array);
var arrayType = arrayExpr.Type as ArrayType;
if (arrayType == null) {
arrayType = new ArrayType(compilation, inst.Type, inst.Indices.Count);
arrayExpr = arrayExpr.ConvertTo(arrayType, this);
}
TranslatedExpression expr = new IndexerExpression(
arrayExpr, inst.Indices.Select(i => TranslateArrayIndex(i).Expression)
).WithILInstruction(inst).WithRR(new ResolveResult(arrayType.ElementType));
return new DirectionExpression(FieldDirection.Ref, expr)
.WithoutILInstruction().WithRR(new ResolveResult(new ByReferenceType(expr.Type)));
}
TranslatedExpression TranslateArrayIndex(ILInstruction i)
{
var stackType = i.ResultType == StackType.I4 ? KnownTypeCode.Int32 : KnownTypeCode.Int64;
return Translate(i).ConvertTo(compilation.FindType(stackType), this);
}
protected internal override TranslatedExpression VisitUnboxAny(UnboxAny inst)
{
var arg = Translate(inst.Argument);
if (arg.Type.IsReferenceType != true) {
// ensure we treat the input as a reference type
arg = arg.ConvertTo(compilation.FindType(KnownTypeCode.Object), this);
}
return new CastExpression(ConvertType(inst.Type), arg.Expression)
.WithILInstruction(inst)
.WithRR(new ConversionResolveResult(inst.Type, arg.ResolveResult, Conversion.UnboxingConversion));
}
protected internal override TranslatedExpression VisitUnbox(Unbox inst)
{
var arg = Translate(inst.Argument);
var castExpression = new CastExpression(ConvertType(inst.Type), arg.Expression)
.WithRR(new ConversionResolveResult(inst.Type, arg.ResolveResult, Conversion.UnboxingConversion));
return new DirectionExpression(FieldDirection.Ref, castExpression)
.WithILInstruction(inst)
.WithRR(new ConversionResolveResult(new ByReferenceType(inst.Type), arg.ResolveResult, Conversion.UnboxingConversion));
}
protected internal override TranslatedExpression VisitBox(Box inst)
{
var obj = compilation.FindType(KnownTypeCode.Object);
var arg = Translate(inst.Argument).ConvertTo(inst.Type, this);
return new CastExpression(ConvertType(obj), arg.Expression)
.WithILInstruction(inst)
.WithRR(new ConversionResolveResult(obj, arg.ResolveResult, Conversion.BoxingConversion));
}
protected internal override TranslatedExpression VisitCastClass(CastClass inst)
{
return Translate(inst.Argument).ConvertTo(inst.Type, this);
}
protected internal override TranslatedExpression VisitArglist(Arglist inst)
{
return new UndocumentedExpression { UndocumentedExpressionType = UndocumentedExpressionType.ArgListAccess }
.WithILInstruction(inst)
.WithRR(new TypeResolveResult(compilation.FindType(new TopLevelTypeName("System", "RuntimeArgumentHandle"))));
}
protected internal override TranslatedExpression VisitMakeRefAny(MakeRefAny inst)
{
var arg = Translate(inst.Argument).Expression;
if (arg is DirectionExpression) {
arg = ((DirectionExpression)arg).Expression;
}
return new UndocumentedExpression {
UndocumentedExpressionType = UndocumentedExpressionType.MakeRef,
Arguments = { arg.Detach() }
}
.WithILInstruction(inst)
.WithRR(new TypeResolveResult(compilation.FindType(new TopLevelTypeName("System", "TypedReference"))));
}
protected internal override TranslatedExpression VisitRefAnyType(RefAnyType inst)
{
return new UndocumentedExpression {
UndocumentedExpressionType = UndocumentedExpressionType.RefType,
Arguments = { Translate(inst.Argument).Expression.Detach() }
}.Member("TypeHandle")
.WithILInstruction(inst)
.WithRR(new TypeResolveResult(compilation.FindType(new TopLevelTypeName("System", "RuntimeTypeHandle"))));
}
protected internal override TranslatedExpression VisitRefAnyValue(RefAnyValue inst)
{
var expr = new UndocumentedExpression {
UndocumentedExpressionType = UndocumentedExpressionType.RefValue,
Arguments = { Translate(inst.Argument).Expression, new TypeReferenceExpression(ConvertType(inst.Type)) }
}.WithRR(new ResolveResult(inst.Type));
return new DirectionExpression(FieldDirection.Ref, expr.WithILInstruction(inst)).WithoutILInstruction()
.WithRR(new ByReferenceResolveResult(inst.Type, false));
}
protected internal override TranslatedExpression VisitBlock(Block block)
{
TranslatedExpression expr;
if (TranslateArrayInitializer(block, out expr))
return expr;
return base.VisitBlock(block);
}
bool TranslateArrayInitializer(Block block, out TranslatedExpression result)
{
result = default(TranslatedExpression);
var stloc = block.Instructions.FirstOrDefault() as StLoc;
var final = block.FinalInstruction as LdLoc;
IType type;
if (stloc == null || final == null || !stloc.Value.MatchNewArr(out type))
return false;
if (stloc.Variable != final.Variable)
return false;
var newArr = (NewArr)stloc.Value;
var translatedDimensions = newArr.Indices.Select(i => Translate(i)).ToArray();
if (!translatedDimensions.All(dim => dim.ResolveResult.IsCompileTimeConstant))
return false;
int dimensions = newArr.Indices.Count;
int[] dimensionSizes = translatedDimensions.Select(dim => (int)dim.ResolveResult.ConstantValue).ToArray();
var container = new Stack<ArrayInitializerExpression>();
var root = new ArrayInitializerExpression();
container.Push(root);
var elementResolveResults = new List<ResolveResult>();
for (int i = 1; i < block.Instructions.Count; i++) {
ILInstruction target, value, array;
IType t;
ILVariable v;
if (!block.Instructions[i].MatchStObj(out target, out value, out t) || !type.Equals(t))
return false;
if (!target.MatchLdElema(out t, out array) || !type.Equals(t))
return false;
if (!array.MatchLdLoc(out v) || v != final.Variable)
return false;
while (container.Count < dimensions) {
var aie = new ArrayInitializerExpression();
container.Peek().Elements.Add(aie);
container.Push(aie);
}
var val = Translate(value).ConvertTo(type, this);
container.Peek().Elements.Add(val);
elementResolveResults.Add(val.ResolveResult);
while (container.Count > 0 && container.Peek().Elements.Count == dimensionSizes[container.Count - 1]) {
container.Pop();
}
}
var expr = new ArrayCreateExpression {
Type = ConvertType(type),
Initializer = root
};
expr.Arguments.AddRange(newArr.Indices.Select(i => Translate(i).Expression));
result = expr.WithILInstruction(block)
.WithRR(new ArrayCreateResolveResult(new ArrayType(compilation, type, dimensions), newArr.Indices.Select(i => Translate(i).ResolveResult).ToArray(), elementResolveResults));
return true;
}
protected internal override TranslatedExpression VisitIfInstruction(IfInstruction inst)
{
var condition = TranslateCondition(inst.Condition);
var targetType = compilation.FindType(inst.ResultType.ToKnownTypeCode());
var trueBranch = Translate(inst.TrueInst).ConvertTo(targetType, this);
var falseBranch = Translate(inst.FalseInst).ConvertTo(targetType, this);
return new ConditionalExpression(condition.Expression, trueBranch.Expression, falseBranch.Expression)
.WithILInstruction(inst)
.WithRR(new ResolveResult(trueBranch.Type));
}
protected internal override TranslatedExpression VisitAddressOf(AddressOf inst)
{
// HACK: this is only correct if the argument is an R-value; otherwise we're missing the copy to the temporary
var value = Translate(inst.Value);
return new DirectionExpression(FieldDirection.Ref, value)
.WithILInstruction(inst)
.WithRR(new ByReferenceResolveResult(value.ResolveResult, false));
}
protected internal override TranslatedExpression VisitInvalidInstruction(InvalidInstruction inst)
{
string message = "Invalid IL";
if (inst.ILRange.Start != 0) {
message += $" near IL_{inst.ILRange.Start:x4}";
}
if (!string.IsNullOrEmpty(inst.Message)) {
message += ": " + inst.Message;
}
return ErrorExpression(message);
}
protected override TranslatedExpression Default(ILInstruction inst)
{
return ErrorExpression("OpCode not supported: " + inst.OpCode);
}
static TranslatedExpression ErrorExpression(string message)
{
var e = new ErrorExpression();
e.AddChild(new Comment(message, CommentType.MultiLine), Roles.Comment);
return e.WithoutILInstruction().WithRR(ErrorResolveResult.UnknownError);
}
}
}