mirror of https://github.com/icsharpcode/ILSpy.git
Siegfried Pammer
6 years ago
30 changed files with 464 additions and 260 deletions
@ -0,0 +1,319 @@
@@ -0,0 +1,319 @@
|
||||
// Copyright (c) 2019 Siegfried Pammer
|
||||
//
|
||||
// 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.TypeSystem; |
||||
|
||||
namespace ICSharpCode.Decompiler.IL.Transforms |
||||
{ |
||||
/// <summary>
|
||||
/// Transforms closure fields to local variables.
|
||||
///
|
||||
/// This is a post-processing step of <see cref="DelegateConstruction"/> and <see cref="TransformExpressionTrees"/>.
|
||||
/// </summary>
|
||||
class TransformDisplayClassUsage : ILVisitor, IILTransform |
||||
{ |
||||
class DisplayClass |
||||
{ |
||||
public bool IsMono; |
||||
public ILInstruction Initializer; |
||||
public ILVariable Variable; |
||||
public ITypeDefinition Definition; |
||||
public Dictionary<IField, DisplayClassVariable> Variables; |
||||
public BlockContainer CaptureScope; |
||||
} |
||||
|
||||
struct DisplayClassVariable |
||||
{ |
||||
public ILVariable Variable; |
||||
public ILInstruction Value; |
||||
} |
||||
|
||||
ILTransformContext context; |
||||
ILFunction currentFunction; |
||||
readonly Dictionary<ILVariable, DisplayClass> displayClasses = new Dictionary<ILVariable, DisplayClass>(); |
||||
readonly List<ILInstruction> instructionsToRemove = new List<ILInstruction>(); |
||||
|
||||
public void Run(ILFunction function, ILTransformContext context) |
||||
{ |
||||
try { |
||||
if (this.context != null || this.currentFunction != null) |
||||
throw new InvalidOperationException("Reentrancy in " + nameof(TransformDisplayClassUsage)); |
||||
this.context = context; |
||||
var decompilationContext = new SimpleTypeResolveContext(context.Function.Method); |
||||
// Traverse nested functions in post-order:
|
||||
// Inner functions are transformed before outer functions
|
||||
foreach (var f in function.Descendants.OfType<ILFunction>()) { |
||||
foreach (var v in f.Variables.ToArray()) { |
||||
if (HandleMonoStateMachine(function, v, decompilationContext, f)) |
||||
continue; |
||||
if (!(v.IsSingleDefinition && v.StoreInstructions.SingleOrDefault() is StLoc inst)) |
||||
continue; |
||||
if (IsClosureInit(inst, out ITypeDefinition closureType)) { |
||||
// TODO : figure out whether it is a mono compiled closure, without relying on the type name
|
||||
bool isMono = f.StateMachineCompiledWithMono || closureType.Name.Contains("AnonStorey"); |
||||
displayClasses.Add(inst.Variable, new DisplayClass { |
||||
IsMono = isMono, |
||||
Initializer = inst, |
||||
Variable = v, |
||||
Definition = closureType, |
||||
Variables = new Dictionary<IField, DisplayClassVariable>(), |
||||
CaptureScope = isMono && IsMonoNestedCaptureScope(closureType) ? null : inst.Variable.CaptureScope |
||||
}); |
||||
instructionsToRemove.Add(inst); |
||||
} |
||||
} |
||||
foreach (var displayClass in displayClasses.Values.OrderByDescending(d => d.Initializer.StartILOffset).ToArray()) { |
||||
context.Step($"Transform references to " + displayClass.Variable, displayClass.Initializer); |
||||
this.currentFunction = f; |
||||
VisitILFunction(f); |
||||
} |
||||
} |
||||
context.Step($"Remove instructions", function); |
||||
foreach (var store in instructionsToRemove) { |
||||
if (store.Parent is Block containingBlock) |
||||
containingBlock.Instructions.Remove(store); |
||||
} |
||||
} finally { |
||||
instructionsToRemove.Clear(); |
||||
displayClasses.Clear(); |
||||
this.context = null; |
||||
this.currentFunction = null; |
||||
} |
||||
} |
||||
|
||||
bool IsOuterClosureReference(IField field) |
||||
{ |
||||
return displayClasses.Values.Any(disp => disp.Definition == field.DeclaringTypeDefinition); |
||||
} |
||||
|
||||
bool IsMonoNestedCaptureScope(ITypeDefinition closureType) |
||||
{ |
||||
var decompilationContext = new SimpleTypeResolveContext(context.Function.Method); |
||||
return closureType.Fields.Any(f => IsPotentialClosure(decompilationContext.CurrentTypeDefinition, f.ReturnType.GetDefinition())); |
||||
} |
||||
|
||||
/// <summary>
|
||||
/// mcs likes to optimize closures in yield state machines away by moving the captured variables' fields into the state machine type,
|
||||
/// We construct a <see cref="DisplayClass"/> that spans the whole method body.
|
||||
/// </summary>
|
||||
bool HandleMonoStateMachine(ILFunction currentFunction, ILVariable thisVariable, SimpleTypeResolveContext decompilationContext, ILFunction nestedFunction) |
||||
{ |
||||
if (!(nestedFunction.StateMachineCompiledWithMono && thisVariable.IsThis())) |
||||
return false; |
||||
// Special case for Mono-compiled yield state machines
|
||||
ITypeDefinition closureType = thisVariable.Type.GetDefinition(); |
||||
if (!(closureType != decompilationContext.CurrentTypeDefinition |
||||
&& IsPotentialClosure(decompilationContext.CurrentTypeDefinition, closureType))) |
||||
return false; |
||||
|
||||
var displayClass = new DisplayClass { |
||||
IsMono = true, |
||||
Initializer = nestedFunction.Body, |
||||
Variable = thisVariable, |
||||
Definition = thisVariable.Type.GetDefinition(), |
||||
Variables = new Dictionary<IField, DisplayClassVariable>(), |
||||
CaptureScope = (BlockContainer)nestedFunction.Body |
||||
}; |
||||
displayClasses.Add(thisVariable, displayClass); |
||||
foreach (var stateMachineVariable in nestedFunction.Variables) { |
||||
if (stateMachineVariable.StateMachineField == null) |
||||
continue; |
||||
displayClass.Variables.Add(stateMachineVariable.StateMachineField, new DisplayClassVariable { |
||||
Variable = stateMachineVariable, |
||||
Value = new LdLoc(stateMachineVariable) |
||||
}); |
||||
} |
||||
if (!currentFunction.Method.IsStatic && FindThisField(out var thisField)) { |
||||
var thisVar = currentFunction.Variables |
||||
.FirstOrDefault(t => t.IsThis() && t.Type.GetDefinition() == decompilationContext.CurrentTypeDefinition); |
||||
if (thisVar == null) { |
||||
thisVar = new ILVariable(VariableKind.Parameter, decompilationContext.CurrentTypeDefinition, -1) { Name = "this" }; |
||||
currentFunction.Variables.Add(thisVar); |
||||
} |
||||
displayClass.Variables.Add(thisField, new DisplayClassVariable { Variable = thisVar, Value = new LdLoc(thisVar) }); |
||||
} |
||||
return true; |
||||
|
||||
bool FindThisField(out IField foundField) |
||||
{ |
||||
foundField = null; |
||||
foreach (var field in closureType.GetFields(f2 => !f2.IsStatic && !displayClass.Variables.ContainsKey(f2) && f2.Type.GetDefinition() == decompilationContext.CurrentTypeDefinition)) { |
||||
thisField = field; |
||||
return true; |
||||
} |
||||
return false; |
||||
} |
||||
} |
||||
|
||||
internal static bool IsSimpleDisplayClass(IType type) |
||||
{ |
||||
if (!type.HasGeneratedName() || (!type.Name.Contains("DisplayClass") && !type.Name.Contains("AnonStorey"))) |
||||
return false; |
||||
if (type.DirectBaseTypes.Any(t => !t.IsKnownType(KnownTypeCode.Object))) |
||||
return false; |
||||
return true; |
||||
} |
||||
|
||||
internal static bool IsPotentialClosure(ILTransformContext context, NewObj inst) |
||||
{ |
||||
var decompilationContext = new SimpleTypeResolveContext(context.Function.Ancestors.OfType<ILFunction>().Last().Method); |
||||
return IsPotentialClosure(decompilationContext.CurrentTypeDefinition, inst.Method.DeclaringTypeDefinition); |
||||
} |
||||
|
||||
internal static bool IsPotentialClosure(ITypeDefinition decompiledTypeDefinition, ITypeDefinition potentialDisplayClass) |
||||
{ |
||||
if (potentialDisplayClass == null || !potentialDisplayClass.IsCompilerGeneratedOrIsInCompilerGeneratedClass()) |
||||
return false; |
||||
while (potentialDisplayClass != decompiledTypeDefinition) { |
||||
potentialDisplayClass = potentialDisplayClass.DeclaringTypeDefinition; |
||||
if (potentialDisplayClass == null) |
||||
return false; |
||||
} |
||||
return true; |
||||
} |
||||
|
||||
protected override void Default(ILInstruction inst) |
||||
{ |
||||
foreach (var child in inst.Children) { |
||||
child.AcceptVisitor(this); |
||||
} |
||||
} |
||||
|
||||
protected internal override void VisitStLoc(StLoc inst) |
||||
{ |
||||
base.VisitStLoc(inst); |
||||
// Sometimes display class references are copied into other local variables.
|
||||
// We remove the assignment and store the relationship between the display class and the variable in the
|
||||
// displayClasses dictionary.
|
||||
if (inst.Value.MatchLdLoc(out var closureVariable) && displayClasses.TryGetValue(closureVariable, out var displayClass)) { |
||||
displayClasses[inst.Variable] = displayClass; |
||||
instructionsToRemove.Add(inst); |
||||
} |
||||
} |
||||
|
||||
bool IsClosureInit(StLoc inst, out ITypeDefinition closureType) |
||||
{ |
||||
closureType = null; |
||||
if (!(inst.Value is NewObj newObj)) |
||||
return false; |
||||
closureType = newObj.Method.DeclaringTypeDefinition; |
||||
return closureType != null && IsPotentialClosure(this.context, newObj); |
||||
} |
||||
|
||||
protected internal override void VisitStObj(StObj inst) |
||||
{ |
||||
base.VisitStObj(inst); |
||||
// This instruction has been marked deletable, do not transform it further
|
||||
if (instructionsToRemove.Contains(inst)) |
||||
return; |
||||
// The target of the store instruction must be a field reference
|
||||
if (!inst.Target.MatchLdFlda(out ILInstruction target, out IField field)) |
||||
return; |
||||
// Get display class info
|
||||
if (!(target is LdLoc displayClassLoad && displayClasses.TryGetValue(displayClassLoad.Variable, out var displayClass))) |
||||
return; |
||||
field = (IField)field.MemberDefinition; |
||||
if (displayClass.Variables.TryGetValue(field, out DisplayClassVariable info)) { |
||||
// If the display class field was previously initialized, we use a simple assignment.
|
||||
inst.ReplaceWith(new StLoc(info.Variable, inst.Value).WithILRange(inst)); |
||||
} else { |
||||
// This is an uninitialized variable:
|
||||
ILInstruction value; |
||||
if (inst.Value.MatchLdLoc(out var v) && v.Kind == VariableKind.Parameter && currentFunction == v.Function) { |
||||
// Special case for parameters: remove copies of parameter values.
|
||||
instructionsToRemove.Add(inst); |
||||
value = inst.Value; |
||||
} else { |
||||
Debug.Assert(displayClass.Definition == field.DeclaringTypeDefinition); |
||||
// Introduce a fresh variable for the display class field.
|
||||
v = currentFunction.RegisterVariable(VariableKind.Local, field.Type, field.Name); |
||||
if (displayClass.IsMono && displayClass.CaptureScope == null && !IsOuterClosureReference(field)) { |
||||
displayClass.CaptureScope = BlockContainer.FindClosestContainer(inst); |
||||
} |
||||
v.CaptureScope = displayClass.CaptureScope; |
||||
inst.ReplaceWith(new StLoc(v, inst.Value).WithILRange(inst)); |
||||
value = new LdLoc(v); |
||||
} |
||||
displayClass.Variables.Add(field, new DisplayClassVariable { Value = value, Variable = v }); |
||||
} |
||||
} |
||||
|
||||
protected internal override void VisitLdObj(LdObj inst) |
||||
{ |
||||
base.VisitLdObj(inst); |
||||
// The target of the store instruction must be a field reference
|
||||
if (!inst.Target.MatchLdFlda(out var target, out IField field)) |
||||
return; |
||||
// Get display class info
|
||||
if (!(target is LdLoc displayClassLoad && displayClasses.TryGetValue(displayClassLoad.Variable, out var displayClass))) |
||||
return; |
||||
// Get display class variable info
|
||||
if (!displayClass.Variables.TryGetValue((IField)field.MemberDefinition, out DisplayClassVariable info)) |
||||
return; |
||||
// Replace usage of display class field with the variable.
|
||||
var replacement = info.Value.Clone(); |
||||
replacement.SetILRange(inst); |
||||
inst.ReplaceWith(replacement); |
||||
} |
||||
|
||||
protected internal override void VisitLdFlda(LdFlda inst) |
||||
{ |
||||
base.VisitLdFlda(inst); |
||||
// TODO : Figure out why this was added in https://github.com/icsharpcode/ILSpy/pull/1303
|
||||
if (inst.Target.MatchLdThis() && inst.Field.Name == "$this" |
||||
&& inst.Field.MemberDefinition.ReflectionName.Contains("c__Iterator")) { |
||||
//Debug.Assert(false, "This should not be executed!");
|
||||
var variable = currentFunction.Variables.First((f) => f.Index == -1); |
||||
inst.ReplaceWith(new LdLoca(variable).WithILRange(inst)); |
||||
} |
||||
// Skip stfld/ldfld
|
||||
if (inst.Parent is LdObj || inst.Parent is StObj) |
||||
return; |
||||
// Get display class info
|
||||
if (!(inst.Target is LdLoc displayClassLoad && displayClasses.TryGetValue(displayClassLoad.Variable, out var displayClass))) |
||||
return; |
||||
var field = (IField)inst.Field.MemberDefinition; |
||||
if (!displayClass.Variables.TryGetValue(field, out DisplayClassVariable info)) { |
||||
// Introduce a fresh variable for the display class field.
|
||||
Debug.Assert(displayClass.Definition == field.DeclaringTypeDefinition); |
||||
var v = currentFunction.RegisterVariable(VariableKind.Local, field.Type, field.Name); |
||||
v.CaptureScope = displayClass.CaptureScope; |
||||
inst.ReplaceWith(new LdLoca(v).WithILRange(inst)); |
||||
displayClass.Variables.Add(field, new DisplayClassVariable { Value = new LdLoc(v), Variable = v }); |
||||
} else if (info.Value is LdLoc l) { |
||||
inst.ReplaceWith(new LdLoca(l.Variable).WithILRange(inst)); |
||||
} else { |
||||
Debug.Fail("LdFlda pattern not supported!"); |
||||
} |
||||
} |
||||
|
||||
protected internal override void VisitNumericCompoundAssign(NumericCompoundAssign inst) |
||||
{ |
||||
base.VisitNumericCompoundAssign(inst); |
||||
// NumericCompoundAssign is only valid when used with fields: -> replace it with a BinaryNumericInstruction.
|
||||
if (inst.Target.MatchLdLoc(out var v)) { |
||||
inst.ReplaceWith(new StLoc(v, new BinaryNumericInstruction(inst.Operator, inst.Target, inst.Value, inst.CheckForOverflow, inst.Sign).WithILRange(inst))); |
||||
} |
||||
} |
||||
|
||||
} |
||||
} |
||||
Loading…
Reference in new issue