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769 lines
29 KiB
769 lines
29 KiB
// Copyright (c) 2014-2017 Daniel Grunwald |
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// |
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// Permission is hereby granted, free of charge, to any person obtaining a copy of this |
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// software and associated documentation files (the "Software"), to deal in the Software |
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// without restriction, including without limitation the rights to use, copy, modify, merge, |
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// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons |
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// to whom the Software is furnished to do so, subject to the following conditions: |
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// |
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// The above copyright notice and this permission notice shall be included in all copies or |
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// substantial portions of the Software. |
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// |
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, |
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// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR |
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// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE |
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// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
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// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
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// DEALINGS IN THE SOFTWARE. |
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using System; |
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using System.Diagnostics; |
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using System.Linq; |
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using System.Linq.Expressions; |
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using ICSharpCode.Decompiler.TypeSystem; |
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namespace ICSharpCode.Decompiler.IL.Transforms |
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{ |
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/// <summary> |
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/// Collection of transforms that detect simple expression patterns |
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/// (e.g. 'cgt.un(..., ld.null)') and replace them with different instructions. |
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/// </summary> |
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/// <remarks> |
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/// Should run after inlining so that the expression patterns can be detected. |
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/// </remarks> |
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public class ExpressionTransforms : ILVisitor, IStatementTransform |
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{ |
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internal StatementTransformContext context; |
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public static void RunOnSingleStatement(ILInstruction statement, ILTransformContext context) |
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{ |
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if (statement == null) |
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throw new ArgumentNullException(nameof(statement)); |
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if (!(statement.Parent is Block parent)) |
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throw new ArgumentException("ILInstruction must be a statement, i.e., direct child of a block."); |
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new ExpressionTransforms().Run(parent, statement.ChildIndex, new StatementTransformContext(new BlockTransformContext(context))); |
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} |
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public void Run(Block block, int pos, StatementTransformContext context) |
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{ |
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this.context = context; |
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context.StepStartGroup($"ExpressionTransforms ({block.Label}:{pos})", block.Instructions[pos]); |
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block.Instructions[pos].AcceptVisitor(this); |
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context.StepEndGroup(keepIfEmpty: true); |
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} |
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protected override void Default(ILInstruction inst) |
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{ |
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foreach (var child in inst.Children) { |
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child.AcceptVisitor(this); |
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} |
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} |
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protected internal override void VisitBlockContainer(BlockContainer container) |
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{ |
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if (container.Kind == ContainerKind.Switch) { |
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// Special case for switch: Only visit the switch condition block. |
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var switchInst = (SwitchInstruction)container.EntryPoint.Instructions[0]; |
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switchInst.Value.AcceptVisitor(this); |
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} |
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// No need to call base.VisitBlockContainer, see comment in VisitBlock. |
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} |
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protected internal override void VisitBlock(Block block) |
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{ |
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if (block.Kind == BlockKind.ControlFlow) { |
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// Don't visit child control flow blocks; |
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// since this is a block transform |
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// we know those were already handled previously. |
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return; |
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} |
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base.VisitBlock(block); |
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} |
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protected internal override void VisitComp(Comp inst) |
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{ |
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// "logic.not(arg)" is sugar for "comp(arg != ldc.i4 0)" |
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if (inst.MatchLogicNot(out var arg)) { |
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VisitLogicNot(inst, arg); |
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return; |
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} else if (inst.Kind == ComparisonKind.Inequality && inst.LiftingKind == ComparisonLiftingKind.None |
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&& inst.Right.MatchLdcI4(0) && (IfInstruction.IsInConditionSlot(inst) || inst.Left is Comp) |
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) { |
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// if (comp(x != 0)) ==> if (x) |
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// comp(comp(...) != 0) => comp(...) |
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context.Step("Remove redundant comp(... != 0)", inst); |
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inst.Left.AddILRange(inst); |
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inst.ReplaceWith(inst.Left); |
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inst.Left.AcceptVisitor(this); |
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return; |
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} |
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base.VisitComp(inst); |
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if (inst.IsLifted) { |
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return; |
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} |
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if (inst.Right.MatchLdNull()) { |
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if (inst.Kind == ComparisonKind.GreaterThan) { |
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context.Step("comp(left > ldnull) => comp(left != ldnull)", inst); |
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inst.Kind = ComparisonKind.Inequality; |
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} else if (inst.Kind == ComparisonKind.LessThanOrEqual) { |
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context.Step("comp(left <= ldnull) => comp(left == ldnull)", inst); |
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inst.Kind = ComparisonKind.Equality; |
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} |
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} else if (inst.Left.MatchLdNull()) { |
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if (inst.Kind == ComparisonKind.LessThan) { |
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context.Step("comp(ldnull < right) => comp(ldnull != right)", inst); |
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inst.Kind = ComparisonKind.Inequality; |
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} else if (inst.Kind == ComparisonKind.GreaterThanOrEqual) { |
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context.Step("comp(ldnull >= right) => comp(ldnull == right)", inst); |
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inst.Kind = ComparisonKind.Equality; |
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} |
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} |
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var rightWithoutConv = inst.Right.UnwrapConv(ConversionKind.SignExtend).UnwrapConv(ConversionKind.ZeroExtend); |
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if (rightWithoutConv.MatchLdcI4(0) |
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&& inst.Sign == Sign.Unsigned |
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&& (inst.Kind == ComparisonKind.GreaterThan || inst.Kind == ComparisonKind.LessThanOrEqual)) |
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{ |
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if (inst.Kind == ComparisonKind.GreaterThan) { |
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context.Step("comp.unsigned(left > ldc.i4 0) => comp(left != ldc.i4 0)", inst); |
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inst.Kind = ComparisonKind.Inequality; |
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VisitComp(inst); |
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return; |
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} else if (inst.Kind == ComparisonKind.LessThanOrEqual) { |
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context.Step("comp.unsigned(left <= ldc.i4 0) => comp(left == ldc.i4 0)", inst); |
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inst.Kind = ComparisonKind.Equality; |
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VisitComp(inst); |
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return; |
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} |
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} else if (rightWithoutConv.MatchLdcI4(0) && inst.Kind.IsEqualityOrInequality()) { |
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if (inst.Left.MatchLdLen(StackType.I, out ILInstruction array)) { |
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// comp.unsigned(ldlen array == conv i4->i(ldc.i4 0)) |
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// => comp(ldlen.i4 array == ldc.i4 0) |
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// This is a special case where the C# compiler doesn't generate conv.i4 after ldlen. |
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context.Step("comp(ldlen.i4 array == ldc.i4 0)", inst); |
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inst.InputType = StackType.I4; |
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inst.Left.ReplaceWith(new LdLen(StackType.I4, array).WithILRange(inst.Left)); |
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inst.Right = rightWithoutConv; |
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} else if (inst.Left is Conv conv && conv.TargetType == PrimitiveType.I && conv.Argument.ResultType == StackType.O) { |
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// C++/CLI sometimes uses this weird comparison with null: |
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context.Step("comp(conv o->i (ldloc obj) == conv i4->i <sign extend>(ldc.i4 0))", inst); |
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// -> comp(ldloc obj == ldnull) |
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inst.InputType = StackType.O; |
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inst.Left = conv.Argument; |
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inst.Right = new LdNull().WithILRange(inst.Right); |
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inst.Right.AddILRange(rightWithoutConv); |
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} |
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} |
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if (inst.Right.MatchLdNull() && inst.Left.MatchBox(out arg, out var type) && type.Kind == TypeKind.TypeParameter) { |
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if (inst.Kind == ComparisonKind.Equality) { |
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context.Step("comp(box T(..) == ldnull) -> comp(.. == ldnull)", inst); |
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inst.Left = arg; |
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} |
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if (inst.Kind == ComparisonKind.Inequality) { |
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context.Step("comp(box T(..) != ldnull) -> comp(.. != ldnull)", inst); |
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inst.Left = arg; |
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} |
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} |
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} |
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protected internal override void VisitConv(Conv inst) |
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{ |
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inst.Argument.AcceptVisitor(this); |
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if (inst.Argument.MatchLdLen(StackType.I, out ILInstruction array) && inst.TargetType.IsIntegerType() |
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&& (!inst.CheckForOverflow || context.Settings.AssumeArrayLengthFitsIntoInt32)) |
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{ |
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context.Step("conv.i4(ldlen array) => ldlen.i4(array)", inst); |
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inst.AddILRange(inst.Argument); |
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inst.ReplaceWith(new LdLen(inst.TargetType.GetStackType(), array).WithILRange(inst)); |
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return; |
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} |
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if (inst.TargetType.IsFloatType() && inst.Argument is Conv conv |
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&& conv.Kind == ConversionKind.IntToFloat && conv.TargetType == PrimitiveType.R) |
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{ |
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// IL conv.r.un does not indicate whether to convert the target type to R4 or R8, |
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// so the C# compiler usually follows it with an explicit conv.r4 or conv.r8. |
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// To avoid emitting '(float)(double)val', we combine these two conversions: |
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context.Step("conv.rN(conv.r.un(...)) => conv.rN.un(...)", inst); |
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inst.ReplaceWith(new Conv(conv.Argument, conv.InputType, conv.InputSign, inst.TargetType, inst.CheckForOverflow, inst.IsLifted | conv.IsLifted)); |
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return; |
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} |
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} |
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protected internal override void VisitBox(Box inst) |
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{ |
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inst.Argument.AcceptVisitor(this); |
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if (inst.Type.IsReferenceType == true && inst.Argument.ResultType == inst.ResultType) { |
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// For reference types, box is a no-op. |
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context.Step("box ref-type(arg) => arg", inst); |
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inst.Argument.AddILRange(inst); |
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inst.ReplaceWith(inst.Argument); |
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} |
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} |
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protected internal override void VisitLdElema(LdElema inst) |
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{ |
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base.VisitLdElema(inst); |
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CleanUpArrayIndices(inst.Indices); |
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} |
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protected internal override void VisitNewArr(NewArr inst) |
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{ |
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base.VisitNewArr(inst); |
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CleanUpArrayIndices(inst.Indices); |
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} |
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void CleanUpArrayIndices(InstructionCollection<ILInstruction> indices) |
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{ |
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foreach (ILInstruction index in indices) { |
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if (index is Conv conv && conv.ResultType == StackType.I |
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&& (conv.Kind == ConversionKind.Truncate && conv.CheckForOverflow |
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|| conv.Kind == ConversionKind.ZeroExtend || conv.Kind == ConversionKind.SignExtend) |
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) { |
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context.Step("Remove conv.i from array index", index); |
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index.ReplaceWith(conv.Argument); |
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} |
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} |
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} |
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void VisitLogicNot(Comp inst, ILInstruction arg) |
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{ |
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ILInstruction lhs, rhs; |
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if (arg is Comp comp) { |
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if ((!comp.InputType.IsFloatType() && !comp.IsLifted) || comp.Kind.IsEqualityOrInequality()) { |
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context.Step("push negation into comparison", inst); |
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comp.Kind = comp.Kind.Negate(); |
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comp.AddILRange(inst); |
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inst.ReplaceWith(comp); |
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} |
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comp.AcceptVisitor(this); |
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} else if (arg.MatchLogicAnd(out lhs, out rhs)) { |
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// logic.not(if (lhs) rhs else ldc.i4 0) |
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// ==> if (logic.not(lhs)) ldc.i4 1 else logic.not(rhs) |
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context.Step("push negation into logic.and", inst); |
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IfInstruction ifInst = (IfInstruction)arg; |
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var ldc0 = ifInst.FalseInst; |
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Debug.Assert(ldc0.MatchLdcI4(0)); |
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ifInst.Condition = Comp.LogicNot(lhs).WithILRange(inst); |
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ifInst.TrueInst = new LdcI4(1).WithILRange(ldc0); |
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ifInst.FalseInst = Comp.LogicNot(rhs).WithILRange(inst); |
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inst.ReplaceWith(ifInst); |
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ifInst.AcceptVisitor(this); |
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} else if (arg.MatchLogicOr(out lhs, out rhs)) { |
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// logic.not(if (lhs) ldc.i4 1 else rhs) |
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// ==> if (logic.not(lhs)) logic.not(rhs) else ldc.i4 0) |
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context.Step("push negation into logic.or", inst); |
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IfInstruction ifInst = (IfInstruction)arg; |
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var ldc1 = ifInst.TrueInst; |
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Debug.Assert(ldc1.MatchLdcI4(1)); |
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ifInst.Condition = Comp.LogicNot(lhs).WithILRange(inst); |
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ifInst.TrueInst = Comp.LogicNot(rhs).WithILRange(inst); |
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ifInst.FalseInst = new LdcI4(0).WithILRange(ldc1); |
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inst.ReplaceWith(ifInst); |
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ifInst.AcceptVisitor(this); |
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} else { |
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arg.AcceptVisitor(this); |
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} |
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} |
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protected internal override void VisitCall(Call inst) |
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{ |
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var expr = EarlyExpressionTransforms.HandleCall(inst, context); |
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if (expr != null) { |
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// The resulting expression may trigger further rules, so continue visiting the replacement: |
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expr.AcceptVisitor(this); |
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} else { |
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base.VisitCall(inst); |
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TransformAssignment.HandleCompoundAssign(inst, context); |
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} |
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} |
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protected internal override void VisitCallVirt(CallVirt inst) |
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{ |
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base.VisitCallVirt(inst); |
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TransformAssignment.HandleCompoundAssign(inst, context); |
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} |
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protected internal override void VisitNewObj(NewObj inst) |
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{ |
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if (TransformDecimalCtorToConstant(inst, out LdcDecimal decimalConstant)) { |
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context.Step("TransformDecimalCtorToConstant", inst); |
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inst.ReplaceWith(decimalConstant); |
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return; |
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} |
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Block block; |
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if (TransformSpanTCtorContainingStackAlloc(inst, out ILInstruction locallocSpan)) { |
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context.Step("new Span<T>(stackalloc) -> stackalloc Span<T>", inst); |
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inst.ReplaceWith(locallocSpan); |
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block = null; |
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ILInstruction stmt = locallocSpan; |
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while (stmt.Parent != null) { |
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if (stmt.Parent is Block b) { |
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block = b; |
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break; |
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} |
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stmt = stmt.Parent; |
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} |
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// Special case to eliminate extra store |
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if (stmt.GetNextSibling() is StLoc storeStmt && storeStmt.Value is LdLoc) |
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ILInlining.InlineIfPossible(block, stmt.ChildIndex, context); |
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return; |
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} |
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if (TransformArrayInitializers.TransformSpanTArrayInitialization(inst, context, out block)) { |
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context.Step("TransformSpanTArrayInitialization: single-dim", inst); |
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inst.ReplaceWith(block); |
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return; |
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} |
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if (TransformDelegateCtorLdVirtFtnToLdVirtDelegate(inst, out LdVirtDelegate ldVirtDelegate)) { |
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context.Step("new Delegate(target, ldvirtftn Method) -> ldvirtdelegate Delegate Method(target)", inst); |
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inst.ReplaceWith(ldVirtDelegate); |
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return; |
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} |
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base.VisitNewObj(inst); |
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} |
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/// <summary> |
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/// newobj Delegate..ctor(target, ldvirtftn TargetMethod(target)) |
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/// => |
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/// ldvirtdelegate System.Delegate TargetMethod(target) |
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/// </summary> |
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bool TransformDelegateCtorLdVirtFtnToLdVirtDelegate(NewObj inst, out LdVirtDelegate ldVirtDelegate) |
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{ |
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ldVirtDelegate = null; |
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if (inst.Method.DeclaringType.Kind != TypeKind.Delegate) |
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return false; |
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if (inst.Arguments.Count != 2) |
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return false; |
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if (!(inst.Arguments[1] is LdVirtFtn ldVirtFtn)) |
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return false; |
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if (!SemanticHelper.IsPure(inst.Arguments[0].Flags)) |
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return false; |
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if (!inst.Arguments[0].Match(ldVirtFtn.Argument).Success) |
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return false; |
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ldVirtDelegate = new LdVirtDelegate(inst.Arguments[0], inst.Method.DeclaringType, ldVirtFtn.Method) |
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.WithILRange(inst).WithILRange(ldVirtFtn).WithILRange(ldVirtFtn.Argument); |
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return true; |
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} |
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/// <summary> |
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/// newobj Span..ctor(localloc(conv i4->u <zero extend>(ldc.i4 sizeInBytes)), numberOfElementsExpr) |
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/// => |
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/// localloc.span T(numberOfElementsExpr) |
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/// |
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/// -or- |
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/// |
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/// newobj Span..ctor(Block IL_0000 (StackAllocInitializer) { |
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/// stloc I_0(localloc(conv i4->u<zero extend>(ldc.i4 sizeInBytes))) |
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/// ... |
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/// final: ldloc I_0 |
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/// }, numberOfElementsExpr) |
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/// => |
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/// Block IL_0000 (StackAllocInitializer) { |
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/// stloc I_0(localloc.span T(numberOfElementsExpr)) |
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/// ... |
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/// final: ldloc I_0 |
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/// } |
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/// </summary> |
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bool TransformSpanTCtorContainingStackAlloc(NewObj newObj, out ILInstruction locallocSpan) |
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{ |
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locallocSpan = null; |
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IType type = newObj.Method.DeclaringType; |
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if (!type.IsKnownType(KnownTypeCode.SpanOfT) && !type.IsKnownType(KnownTypeCode.ReadOnlySpanOfT)) |
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return false; |
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if (newObj.Arguments.Count != 2 || type.TypeArguments.Count != 1) |
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return false; |
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IType elementType = type.TypeArguments[0]; |
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if (newObj.Arguments[0].MatchLocAlloc(out var sizeInBytes) && MatchesElementCount(sizeInBytes, elementType, newObj.Arguments[1])) { |
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locallocSpan = new LocAllocSpan(newObj.Arguments[1], type); |
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return true; |
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} |
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if (newObj.Arguments[0] is Block initializer && initializer.Kind == BlockKind.StackAllocInitializer) { |
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if (!initializer.Instructions[0].MatchStLoc(out var initializerVariable, out var value)) |
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return false; |
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if (!(value.MatchLocAlloc(out sizeInBytes) && MatchesElementCount(sizeInBytes, elementType, newObj.Arguments[1]))) |
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return false; |
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var newVariable = initializerVariable.Function.RegisterVariable(VariableKind.InitializerTarget, type); |
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foreach (var load in initializerVariable.LoadInstructions.ToArray()) { |
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ILInstruction newInst = new LdLoc(newVariable); |
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newInst.AddILRange(load); |
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if (load.Parent != initializer) |
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newInst = new Conv(newInst, PrimitiveType.I, false, Sign.None); |
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load.ReplaceWith(newInst); |
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} |
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foreach (var store in initializerVariable.StoreInstructions.ToArray()) { |
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store.Variable = newVariable; |
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} |
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value.ReplaceWith(new LocAllocSpan(newObj.Arguments[1], type)); |
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locallocSpan = initializer; |
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return true; |
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} |
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return false; |
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} |
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bool MatchesElementCount(ILInstruction sizeInBytesInstr, IType elementType, ILInstruction elementCountInstr2) |
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{ |
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var pointerType = new PointerType(elementType); |
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var elementCountInstr = PointerArithmeticOffset.Detect(sizeInBytesInstr, pointerType.ElementType, checkForOverflow: true, unwrapZeroExtension: true); |
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if (!elementCountInstr.Match(elementCountInstr2).Success) |
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return false; |
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return true; |
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} |
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bool TransformDecimalCtorToConstant(NewObj inst, out LdcDecimal result) |
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{ |
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IType t = inst.Method.DeclaringType; |
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result = null; |
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if (!t.IsKnownType(KnownTypeCode.Decimal)) |
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return false; |
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var args = inst.Arguments; |
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if (args.Count == 1) { |
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int val; |
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if (args[0].MatchLdcI4(out val)) { |
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result = new LdcDecimal(val); |
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return true; |
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} |
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} else if (args.Count == 5) { |
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int lo, mid, hi, isNegative, scale; |
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if (args[0].MatchLdcI4(out lo) && args[1].MatchLdcI4(out mid) && |
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args[2].MatchLdcI4(out hi) && args[3].MatchLdcI4(out isNegative) && |
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args[4].MatchLdcI4(out scale)) |
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{ |
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result = new LdcDecimal(new decimal(lo, mid, hi, isNegative != 0, (byte)scale)); |
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return true; |
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} |
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} |
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return false; |
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} |
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|
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bool TransformDecimalFieldToConstant(LdObj inst, out LdcDecimal result) |
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{ |
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if (inst.MatchLdsFld(out var field) && field.DeclaringType.IsKnownType(KnownTypeCode.Decimal)) { |
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decimal? value = null; |
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if (field.Name == "One") { |
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value = decimal.One; |
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} else if (field.Name == "MinusOne") { |
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value = decimal.MinusOne; |
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} else if (field.Name == "Zero") { |
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value = decimal.Zero; |
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} |
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if (value != null) { |
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result = new LdcDecimal(value.Value).WithILRange(inst).WithILRange(inst.Target); |
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return true; |
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} |
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} |
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result = null; |
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return false; |
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} |
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protected internal override void VisitLdObj(LdObj inst) |
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{ |
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base.VisitLdObj(inst); |
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EarlyExpressionTransforms.AddressOfLdLocToLdLoca(inst, context); |
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if (EarlyExpressionTransforms.LdObjToLdLoc(inst, context)) |
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return; |
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if (TransformDecimalFieldToConstant(inst, out LdcDecimal decimalConstant)) { |
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context.Step("TransformDecimalFieldToConstant", inst); |
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inst.ReplaceWith(decimalConstant); |
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return; |
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} |
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} |
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protected internal override void VisitStObj(StObj inst) |
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{ |
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base.VisitStObj(inst); |
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if (EarlyExpressionTransforms.StObjToStLoc(inst, context)) { |
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context.RequestRerun(); |
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return; |
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} |
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TransformAssignment.HandleCompoundAssign(inst, context); |
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} |
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|
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protected internal override void VisitStLoc(StLoc inst) |
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{ |
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base.VisitStLoc(inst); |
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TransformAssignment.HandleCompoundAssign(inst, context); |
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} |
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|
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protected internal override void VisitIfInstruction(IfInstruction inst) |
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{ |
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inst.TrueInst.AcceptVisitor(this); |
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inst.FalseInst.AcceptVisitor(this); |
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inst = HandleConditionalOperator(inst); |
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|
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// Bring LogicAnd/LogicOr into their canonical forms: |
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// if (cond) ldc.i4 0 else RHS --> if (!cond) RHS else ldc.i4 0 |
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// if (cond) RHS else ldc.i4 1 --> if (!cond) ldc.i4 1 else RHS |
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// Be careful: when both LHS and RHS are the constant 1, we must not |
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// swap the arguments as it would lead to an infinite transform loop. |
|
if (inst.TrueInst.MatchLdcI4(0) && !inst.FalseInst.MatchLdcI4(0) |
|
|| inst.FalseInst.MatchLdcI4(1) && !inst.TrueInst.MatchLdcI4(1)) |
|
{ |
|
context.Step("canonicalize logic and/or", inst); |
|
var t = inst.TrueInst; |
|
inst.TrueInst = inst.FalseInst; |
|
inst.FalseInst = t; |
|
inst.Condition = Comp.LogicNot(inst.Condition); |
|
} |
|
// Process condition after our potential modifications. |
|
inst.Condition.AcceptVisitor(this); |
|
|
|
if (new NullableLiftingTransform(context).Run(inst)) |
|
return; |
|
|
|
if (TransformDynamicAddAssignOrRemoveAssign(inst)) |
|
return; |
|
if (inst.MatchIfInstructionPositiveCondition(out var condition, out var trueInst, out var falseInst)) { |
|
ILInstruction transformed = UserDefinedLogicTransform.Transform(condition, trueInst, falseInst); |
|
if (transformed == null) { |
|
transformed = UserDefinedLogicTransform.TransformDynamic(condition, trueInst, falseInst); |
|
} |
|
if (transformed != null) { |
|
context.Step("User-defined short-circuiting logic operator (roslyn pattern)", condition); |
|
transformed.AddILRange(inst); |
|
inst.ReplaceWith(transformed); |
|
return; |
|
} |
|
} |
|
} |
|
|
|
/// <summary> |
|
/// op is either add or remove/subtract: |
|
/// if (dynamic.isevent (target)) { |
|
/// dynamic.invokemember.invokespecial.discard op_Name(target, value) |
|
/// } else { |
|
/// dynamic.compound.op (dynamic.getmember Name(target), value) |
|
/// } |
|
/// => |
|
/// dynamic.compound.op (dynamic.getmember Name(target), value) |
|
/// </summary> |
|
bool TransformDynamicAddAssignOrRemoveAssign(IfInstruction inst) |
|
{ |
|
if (!inst.MatchIfInstructionPositiveCondition(out var condition, out var trueInst, out var falseInst)) |
|
return false; |
|
if (!(condition is DynamicIsEventInstruction isEvent)) |
|
return false; |
|
trueInst = Block.Unwrap(trueInst); |
|
falseInst = Block.Unwrap(falseInst); |
|
if (!(falseInst is DynamicCompoundAssign dynamicCompoundAssign)) |
|
return false; |
|
if (!(dynamicCompoundAssign.Target is DynamicGetMemberInstruction getMember)) |
|
return false; |
|
if (!SemanticHelper.IsPure(isEvent.Argument.Flags)) |
|
return false; |
|
if (!isEvent.Argument.Match(getMember.Target).Success) |
|
return false; |
|
if (!(trueInst is DynamicInvokeMemberInstruction invokeMember)) |
|
return false; |
|
if (!(invokeMember.BinderFlags.HasFlag(CSharpBinderFlags.InvokeSpecialName) && invokeMember.BinderFlags.HasFlag(CSharpBinderFlags.ResultDiscarded))) |
|
return false; |
|
switch (dynamicCompoundAssign.Operation) { |
|
case ExpressionType.AddAssign: |
|
if (invokeMember.Name != "add_" + getMember.Name) |
|
return false; |
|
break; |
|
case ExpressionType.SubtractAssign: |
|
if (invokeMember.Name != "remove_" + getMember.Name) |
|
return false; |
|
break; |
|
default: |
|
return false; |
|
} |
|
if (!dynamicCompoundAssign.Value.Match(invokeMember.Arguments[1]).Success) |
|
return false; |
|
if (!invokeMember.Arguments[0].Match(getMember.Target).Success) |
|
return false; |
|
context.Step("+= / -= dynamic.isevent pattern -> dynamic.compound.op", inst); |
|
inst.ReplaceWith(dynamicCompoundAssign); |
|
return true; |
|
} |
|
|
|
/// <summary> |
|
/// dynamic.setmember.compound Name(target, dynamic.binary.operator op(dynamic.getmember Name(target), value)) |
|
/// => |
|
/// dynamic.compound.op (dynamic.getmember Name(target), value) |
|
/// </summary> |
|
protected internal override void VisitDynamicSetMemberInstruction(DynamicSetMemberInstruction inst) |
|
{ |
|
base.VisitDynamicSetMemberInstruction(inst); |
|
TransformDynamicSetMemberInstruction(inst, context); |
|
} |
|
|
|
internal static void TransformDynamicSetMemberInstruction(DynamicSetMemberInstruction inst, StatementTransformContext context) |
|
{ |
|
if (!inst.BinderFlags.HasFlag(CSharpBinderFlags.ValueFromCompoundAssignment)) |
|
return; |
|
if (!(inst.Value is DynamicBinaryOperatorInstruction binaryOp)) |
|
return; |
|
if (!(binaryOp.Left is DynamicGetMemberInstruction dynamicGetMember)) |
|
return; |
|
if (!dynamicGetMember.Target.Match(inst.Target).Success) |
|
return; |
|
if (!SemanticHelper.IsPure(dynamicGetMember.Target.Flags)) |
|
return; |
|
if (inst.Name != dynamicGetMember.Name || !DynamicCompoundAssign.IsExpressionTypeSupported(binaryOp.Operation)) |
|
return; |
|
context.Step("dynamic.setmember.compound -> dynamic.compound.op", inst); |
|
inst.ReplaceWith(new DynamicCompoundAssign(binaryOp.Operation, binaryOp.BinderFlags, binaryOp.Left, binaryOp.LeftArgumentInfo, binaryOp.Right, binaryOp.RightArgumentInfo)); |
|
} |
|
|
|
/// <summary> |
|
/// dynamic.setindex.compound(target, index, dynamic.binary.operator op(dynamic.getindex(target, index), value)) |
|
/// => |
|
/// dynamic.compound.op (dynamic.getindex(target, index), value) |
|
/// </summary> |
|
protected internal override void VisitDynamicSetIndexInstruction(DynamicSetIndexInstruction inst) |
|
{ |
|
base.VisitDynamicSetIndexInstruction(inst); |
|
|
|
if (!inst.BinderFlags.HasFlag(CSharpBinderFlags.ValueFromCompoundAssignment)) |
|
return; |
|
if (!(inst.Arguments.LastOrDefault() is DynamicBinaryOperatorInstruction binaryOp)) |
|
return; |
|
if (!(binaryOp.Left is DynamicGetIndexInstruction dynamicGetIndex)) |
|
return; |
|
if (inst.Arguments.Count != dynamicGetIndex.Arguments.Count + 1) |
|
return; |
|
// Ensure that same arguments are passed to dynamicGetIndex and inst: |
|
for (int j = 0; j < dynamicGetIndex.Arguments.Count; j++) { |
|
if (!SemanticHelper.IsPure(dynamicGetIndex.Arguments[j].Flags)) |
|
return; |
|
if (!dynamicGetIndex.Arguments[j].Match(inst.Arguments[j]).Success) |
|
return; |
|
} |
|
if (!DynamicCompoundAssign.IsExpressionTypeSupported(binaryOp.Operation)) |
|
return; |
|
context.Step("dynamic.setindex.compound -> dynamic.compound.op", inst); |
|
inst.ReplaceWith(new DynamicCompoundAssign(binaryOp.Operation, binaryOp.BinderFlags, binaryOp.Left, binaryOp.LeftArgumentInfo, binaryOp.Right, binaryOp.RightArgumentInfo)); |
|
} |
|
|
|
IfInstruction HandleConditionalOperator(IfInstruction inst) |
|
{ |
|
// if (cond) stloc (A, V1) else stloc (A, V2) --> stloc (A, if (cond) V1 else V2) |
|
Block trueInst = inst.TrueInst as Block; |
|
if (trueInst == null || trueInst.Instructions.Count != 1) |
|
return inst; |
|
Block falseInst = inst.FalseInst as Block; |
|
if (falseInst == null || falseInst.Instructions.Count != 1) |
|
return inst; |
|
ILVariable v; |
|
ILInstruction value1, value2; |
|
if (trueInst.Instructions[0].MatchStLoc(out v, out value1) && falseInst.Instructions[0].MatchStLoc(v, out value2)) { |
|
context.Step("conditional operator", inst); |
|
var newIf = new IfInstruction(Comp.LogicNot(inst.Condition), value2, value1); |
|
newIf.AddILRange(inst); |
|
inst.ReplaceWith(new StLoc(v, newIf)); |
|
context.RequestRerun(); // trigger potential inlining of the newly created StLoc |
|
return newIf; |
|
} |
|
return inst; |
|
} |
|
|
|
protected internal override void VisitBinaryNumericInstruction(BinaryNumericInstruction inst) |
|
{ |
|
base.VisitBinaryNumericInstruction(inst); |
|
switch (inst.Operator) { |
|
case BinaryNumericOperator.ShiftLeft: |
|
case BinaryNumericOperator.ShiftRight: |
|
if (inst.Right.MatchBinaryNumericInstruction(BinaryNumericOperator.BitAnd, out var lhs, out var rhs) |
|
&& rhs.MatchLdcI4(inst.ResultType == StackType.I8 ? 63 : 31)) |
|
{ |
|
// a << (b & 31) => a << b |
|
context.Step("Combine bit.and into shift", inst); |
|
inst.Right = lhs; |
|
} |
|
break; |
|
case BinaryNumericOperator.BitAnd: |
|
if (inst.Left.InferType(context.TypeSystem).IsKnownType(KnownTypeCode.Boolean) |
|
&& inst.Right.InferType(context.TypeSystem).IsKnownType(KnownTypeCode.Boolean)) |
|
{ |
|
if (new NullableLiftingTransform(context).Run(inst)) { |
|
// e.g. "(a.GetValueOrDefault() == b.GetValueOrDefault()) & (a.HasValue & b.HasValue)" |
|
} else if (SemanticHelper.IsPure(inst.Right.Flags)) { |
|
context.Step("Replace bit.and with logic.and", inst); |
|
var expr = IfInstruction.LogicAnd(inst.Left, inst.Right); |
|
inst.ReplaceWith(expr); |
|
expr.AcceptVisitor(this); |
|
} |
|
} |
|
break; |
|
} |
|
} |
|
|
|
protected internal override void VisitTryCatchHandler(TryCatchHandler inst) |
|
{ |
|
base.VisitTryCatchHandler(inst); |
|
if (inst.Filter is BlockContainer filterContainer && filterContainer.Blocks.Count == 1) { |
|
TransformCatchWhen(inst, filterContainer.EntryPoint); |
|
} |
|
if (inst.Body is BlockContainer catchContainer) |
|
TransformCatchVariable(inst, catchContainer.EntryPoint); |
|
} |
|
|
|
/// <summary> |
|
/// catch ex : TException when (...) BlockContainer { |
|
/// Block entryPoint (incoming: 1) { |
|
/// stloc v(ldloc ex) |
|
/// ... |
|
/// } |
|
/// } |
|
/// => |
|
/// catch v : TException when (...) BlockContainer { |
|
/// Block entryPoint (incoming: 1) { |
|
/// ... |
|
/// } |
|
/// } |
|
/// </summary> |
|
void TransformCatchVariable(TryCatchHandler handler, Block entryPoint) |
|
{ |
|
if (!handler.Variable.IsSingleDefinition || handler.Variable.LoadCount != 1) |
|
return; // handle.Variable already has non-trivial uses |
|
if (!entryPoint.Instructions[0].MatchStLoc(out var exceptionVar, out var exceptionSlotLoad)) { |
|
// Not the pattern with a second exceptionVar. |
|
// However, it is still possible that we need to remove a pointless UnboxAny: |
|
if (handler.Variable.LoadInstructions.Single().Parent is UnboxAny inlinedUnboxAny) { |
|
if (inlinedUnboxAny.Type.Equals(handler.Variable.Type)) { |
|
context.Step("TransformCatchVariable - remove inlined UnboxAny", inlinedUnboxAny); |
|
inlinedUnboxAny.ReplaceWith(inlinedUnboxAny.Argument); |
|
} |
|
} |
|
return; |
|
} |
|
if (exceptionVar.Kind != VariableKind.Local && exceptionVar.Kind != VariableKind.StackSlot) |
|
return; |
|
if (exceptionSlotLoad is UnboxAny unboxAny) { |
|
// When catching a type parameter, csc emits an unbox.any instruction |
|
if (!unboxAny.Type.Equals(handler.Variable.Type)) |
|
return; |
|
exceptionSlotLoad = unboxAny.Argument; |
|
} |
|
if (!exceptionSlotLoad.MatchLdLoc(handler.Variable)) |
|
return; |
|
// Check that exceptionVar is only used within the catch block: |
|
var allUses = exceptionVar.LoadInstructions |
|
.Concat(exceptionVar.StoreInstructions.Cast<ILInstruction>()) |
|
.Concat(exceptionVar.AddressInstructions); |
|
foreach (var inst in allUses) { |
|
if (!inst.IsDescendantOf(handler)) |
|
return; |
|
} |
|
context.Step("TransformCatchVariable", entryPoint.Instructions[0]); |
|
exceptionVar.Kind = VariableKind.ExceptionLocal; |
|
exceptionVar.Type = handler.Variable.Type; |
|
handler.Variable = exceptionVar; |
|
entryPoint.Instructions.RemoveAt(0); |
|
} |
|
|
|
/// <summary> |
|
/// Inline condition from catch-when condition BlockContainer, if possible. |
|
/// </summary> |
|
void TransformCatchWhen(TryCatchHandler handler, Block entryPoint) |
|
{ |
|
TransformCatchVariable(handler, entryPoint); |
|
if (entryPoint.Instructions.Count == 1 && entryPoint.Instructions[0].MatchLeave(out _, out var condition)) { |
|
context.Step("TransformCatchWhen", entryPoint.Instructions[0]); |
|
handler.Filter = condition; |
|
} |
|
} |
|
} |
|
}
|
|
|