You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
69 lines
2.8 KiB
69 lines
2.8 KiB
// Copyright (c) 2020 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.Collections.Generic;
|
|
using System.Linq;
|
|
|
|
using ICSharpCode.Decompiler.CSharp;
|
|
|
|
namespace ICSharpCode.Decompiler.IL.Transforms
|
|
{
|
|
/// <summary>
|
|
/// C# cannot represent `isinst T` directly for value-types.
|
|
/// This transform un-inlines the argument of `isinst` instructions that can't be directly translated to C#,
|
|
/// thus allowing the emulation via "expr is T ? (T)expr : null".
|
|
/// </summary>
|
|
public class FixLoneIsInst : IILTransform
|
|
{
|
|
void IILTransform.Run(ILFunction function, ILTransformContext context)
|
|
{
|
|
var instructionsToFix = new List<IsInst>();
|
|
foreach (var isInst in function.Descendants.OfType<IsInst>())
|
|
{
|
|
if (isInst.Type.IsReferenceType == true)
|
|
{
|
|
continue; // reference-type isinst is always supported
|
|
}
|
|
if (SemanticHelper.IsPure(isInst.Argument.Flags))
|
|
{
|
|
continue; // emulated via "expr is T ? (T)expr : null"
|
|
}
|
|
if (isInst.Parent is UnboxAny unboxAny && ExpressionBuilder.IsUnboxAnyWithIsInst(unboxAny, isInst))
|
|
{
|
|
continue; // supported pattern "expr as T?"
|
|
}
|
|
if (isInst.Parent.MatchCompEqualsNull(out _) || isInst.Parent.MatchCompNotEqualsNull(out _))
|
|
{
|
|
continue; // supported pattern "expr is T"
|
|
}
|
|
if (isInst.Parent is Block { Kind: BlockKind.ControlFlow })
|
|
{
|
|
continue; // supported via StatementBuilder.VisitIsInst
|
|
}
|
|
instructionsToFix.Add(isInst);
|
|
}
|
|
// Need to delay fixing until we're done with iteration, because Extract() modifies parents
|
|
foreach (var isInst in instructionsToFix)
|
|
{
|
|
// Use extraction to turn isInst.Argument into a pure instruction, thus making the emulation possible
|
|
context.Step("FixLoneIsInst", isInst);
|
|
isInst.Argument.Extract(context);
|
|
}
|
|
}
|
|
}
|
|
}
|