.NET Decompiler with support for PDB generation, ReadyToRun, Metadata (&more) - cross-platform!
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.
 
 
 
 

312 lines
11 KiB

// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
//
// 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.Linq;
using Mono.Cecil;
namespace ICSharpCode.Decompiler.ILAst
{
partial class ILAstOptimizer
{
bool SimplifyNullableOperators(List<ILNode> body, ILExpression expr, int pos)
{
if (!SimplifyNullableOperators(expr)) return false;
var inlining = new ILInlining(method);
while (--pos >= 0 && inlining.InlineIfPossible(body, ref pos)) ;
return true;
}
static bool SimplifyNullableOperators(ILExpression expr)
{
if (IsNullableOperation(expr)) return true;
bool modified = false;
foreach (var a in expr.Arguments)
modified |= SimplifyNullableOperators(a);
return modified;
}
static bool IsNullableOperation(ILExpression expr)
{
if (expr.Code != ILCode.LogicAnd && expr.Code != ILCode.LogicOr) return false;
var ps = PatternMatcher.Comparisons;
for (int i = 0; i < ps.Length; i += 2) {
var pm = new PatternMatcher();
if (!pm.Match(ps[i], expr)) continue;
var n = pm.BuildNew(ps[i + 1], expr);
expr.Code = n.Code;
expr.Operand = n.Operand;
expr.Arguments = n.Arguments;
expr.ILRanges = n.ILRanges;
return true;
}
return false;
}
struct PatternMatcher
{
public abstract class Pattern
{
public readonly Pattern[] Arguments;
protected static readonly Pattern[] EmptyArguments = new Pattern[0];
protected Pattern(Pattern[] arguments)
{
this.Arguments = arguments;
}
public abstract bool Match(ref PatternMatcher pm, ILExpression e);
public virtual ILExpression BuildNew(ref PatternMatcher pm, ILExpression[] args)
{
throw new NotSupportedException();
}
}
sealed class ILPattern : Pattern
{
readonly ILCode code;
public ILPattern(ILCode code, params Pattern[] arguments)
: base(arguments)
{
this.code = code;
}
public override bool Match(ref PatternMatcher pm, ILExpression e)
{
return e.Code == this.code;
}
public override ILExpression BuildNew(ref PatternMatcher pm, ILExpression[] args)
{
return new ILExpression(this.code, null, args);
}
}
sealed class MethodPattern : Pattern
{
readonly ILCode code;
readonly Tuple<string, string, string> method;
public MethodPattern(ILCode code, Tuple<string, string, string> method, params Pattern[] arguments)
: base(arguments)
{
this.code = code;
this.method = method;
}
public override bool Match(ref PatternMatcher pm, ILExpression e)
{
if (e.Code != this.code) return false;
var m = e.Operand as MethodReference;
if (m == null || m.Name != this.method.Item1) return false;
var t = m.DeclaringType;
return t.Name == this.method.Item2 && t.Namespace == this.method.Item3;
}
}
sealed class OperatorPattern : Pattern
{
bool? equals, custom;
public OperatorPattern(params Pattern[] arguments) : base(arguments) { }
public OperatorPattern(bool? equals, bool? custom, params Pattern[] arguments)
: base(arguments)
{
this.equals = equals;
this.custom = custom;
}
public override bool Match(ref PatternMatcher pm, ILExpression e)
{
switch (e.Code) {
case ILCode.Ceq:
if (!equals.GetValueOrDefault() || custom.GetValueOrDefault()) return false;
break;
case ILCode.Cgt:
case ILCode.Cgt_Un:
case ILCode.Clt:
case ILCode.Clt_Un:
if (equals != null || custom.GetValueOrDefault()) return false;
break;
case ILCode.Call:
if (custom != null && !custom.GetValueOrDefault()) return false;
var m = e.Operand as MethodReference;
if (m == null || m.HasThis || !m.HasParameters || m.Parameters.Count != base.Arguments.Length || !IsCustomOperator(m)) return false;
break;
default: return false;
}
if (pm.Operator != null) throw new InvalidOperationException();
pm.Operator = e;
return true;
}
bool IsCustomOperator(MethodReference m)
{
switch (m.Name) {
case "op_Equality":
return equals.GetValueOrDefault();
case "op_Inequality":
return equals != null && !equals.GetValueOrDefault();
case "op_GreaterThan":
case "op_GreaterThanOrEqual":
case "op_LessThan":
case "op_LessThanOrEqual":
return equals == null;
default: return false;
}
}
public override ILExpression BuildNew(ref PatternMatcher pm, ILExpression[] args)
{
var res = pm.Operator;
res.Arguments.Clear();
res.Arguments.AddRange(args);
return res;
}
}
sealed class VariablePattern : Pattern
{
readonly ILCode code;
readonly bool b;
public VariablePattern(ILCode code, bool b)
: base(EmptyArguments)
{
this.code = code;
this.b = b;
}
public override bool Match(ref PatternMatcher pm, ILExpression e)
{
if (e.Code != this.code) return false;
var v = e.Operand as ILVariable;
return v != null && (this.b ? Capture(ref pm.B, v) : Capture(ref pm.A, v));
}
static bool Capture(ref ILVariable pmvar, ILVariable v)
{
if (pmvar != null) return pmvar == v;
pmvar = v;
return true;
}
public override ILExpression BuildNew(ref PatternMatcher pm, ILExpression[] args)
{
return new ILExpression(this.code, this.b ? pm.B : pm.A, args);
}
}
sealed class PrimitivePattern : Pattern
{
readonly ILCode code;
readonly object operand;
public PrimitivePattern(ILCode code, object operand, params Pattern[] arguments)
: base(arguments)
{
this.code = code;
this.operand = operand;
}
public override bool Match(ref PatternMatcher pm, ILExpression e)
{
return e.Code == code && object.Equals(e.Operand, this.operand);
}
}
static readonly Tuple<string, string, string> GetValueOrDefault = new Tuple<string, string, string>("GetValueOrDefault", "Nullable`1", "System");
static readonly Tuple<string, string, string> get_HasValue = new Tuple<string, string, string>("get_HasValue", "Nullable`1", "System");
static readonly VariablePattern VariableRefA = new VariablePattern(ILCode.Ldloca, false), VariableRefB = new VariablePattern(ILCode.Ldloca, true);
static readonly OperatorPattern OperatorVariableAB = new OperatorPattern(new VariablePattern(ILCode.Ldloc, false), new VariablePattern(ILCode.Ldloc, true));
static readonly MethodPattern[] Call2GetValueOrDefault = new[] {
new MethodPattern(ILCode.Call, GetValueOrDefault, VariableRefA),
new MethodPattern(ILCode.Call, GetValueOrDefault, VariableRefB)};
static readonly MethodPattern CallVariableAget_HasValue = new MethodPattern(ILCode.CallGetter, get_HasValue, VariableRefA);
static readonly MethodPattern[] Call2get_HasValue = new[] { CallVariableAget_HasValue, new MethodPattern(ILCode.CallGetter, get_HasValue, VariableRefB) };
static readonly Pattern CeqHasValue = new ILPattern(ILCode.Ceq, Call2get_HasValue);
static readonly Pattern AndHasValue = new ILPattern(ILCode.And, Call2get_HasValue);
public static readonly Pattern[] Comparisons = new Pattern[] {
// == (Primitive, Decimal)
new ILPattern(ILCode.LogicAnd, new ILPattern(ILCode.LogicNot, new ILPattern(ILCode.LogicNot, new OperatorPattern(true, null, Call2GetValueOrDefault))), CeqHasValue),
OperatorVariableAB,
// == (Struct)
new ILPattern(ILCode.LogicAnd,
new ILPattern(ILCode.LogicNot, new ILPattern(ILCode.LogicNot, CeqHasValue)),
new ILPattern(ILCode.LogicOr, new ILPattern(ILCode.LogicNot, CallVariableAget_HasValue), new OperatorPattern(true, true, Call2GetValueOrDefault))),
OperatorVariableAB,
// != (P)
new ILPattern(ILCode.LogicOr,
new ILPattern(ILCode.LogicNot, new OperatorPattern(true, false, Call2GetValueOrDefault)),
new ILPattern(ILCode.Ceq, CeqHasValue, new PrimitivePattern(ILCode.Ldc_I4, 0))),
new ILPattern(ILCode.LogicNot, OperatorVariableAB),
// != (D)
new ILPattern(ILCode.LogicOr,
new OperatorPattern(false, true, Call2GetValueOrDefault),
new ILPattern(ILCode.Ceq, CeqHasValue, new PrimitivePattern(ILCode.Ldc_I4, 0))),
OperatorVariableAB,
// != (S)
new ILPattern(ILCode.LogicOr,
new ILPattern(ILCode.LogicNot, CeqHasValue),
new ILPattern(ILCode.LogicAnd,
new ILPattern(ILCode.LogicNot, new ILPattern(ILCode.LogicNot, CallVariableAget_HasValue)),
new OperatorPattern(false, true, Call2GetValueOrDefault))),
OperatorVariableAB,
// > (P, D), < (P, D), >= (D), <= (D)
new ILPattern(ILCode.LogicAnd, new ILPattern(ILCode.LogicNot, new ILPattern(ILCode.LogicNot, new OperatorPattern(null, null, Call2GetValueOrDefault))), AndHasValue),
OperatorVariableAB,
// >= (P), <= (P)
new ILPattern(ILCode.LogicAnd, new ILPattern(ILCode.LogicNot, new OperatorPattern(null, false, Call2GetValueOrDefault)), AndHasValue),
new ILPattern(ILCode.LogicNot, OperatorVariableAB),
// > (S), < (S), >= (S), <= (S)
new ILPattern(ILCode.LogicAnd, AndHasValue, new OperatorPattern(null, true, Call2GetValueOrDefault)),
OperatorVariableAB,
};
public ILVariable A, B;
public ILExpression Operator;
public bool Match(Pattern p, ILExpression e)
{
if (!p.Match(ref this, e) || e.Arguments.Count != p.Arguments.Length || e.Prefixes != null) return false;
for (int i = 0; i < p.Arguments.Length; i++)
if (!Match(p.Arguments[i], e.Arguments[i])) return false;
return true;
}
public ILExpression BuildNew(Pattern p, ILExpression old)
{
var args = new ILExpression[p.Arguments.Length];
for (int i = 0; i < args.Length; i++) args[i] = BuildNew(p.Arguments[i], old);
var res = p.BuildNew(ref this, args);
if (args.Length == 2) res.ILRanges = ILRange.OrderAndJoint(old.GetSelfAndChildrenRecursive<ILExpression>().SelectMany(el => el.ILRanges));
return res;
}
}
}
}