pimhwang
/
ILSpy
mirror of https://github.com/icsharpcode/ILSpy.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

Fix switch-on-string transform for optimized Roslyn.

pull/3362/head
Siegfried Pammer 6 months ago
parent
e4285b751b
commit
e1e2f739f6
2 changed files with 148 additions and 41 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 100
      ICSharpCode.Decompiler.Tests/TestCases/Pretty/Switch.cs
  2. 41
      ICSharpCode.Decompiler/IL/Transforms/SwitchOnStringTransform.cs

100
ICSharpCode.Decompiler.Tests/TestCases/Pretty/Switch.cs
Unescape View File

@ -82,6 +82,46 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
} }
} }
public class ImplicitConversionConflictWithLong
{
private readonly int s;
public ImplicitConversionConflictWithLong(int s)
{
this.s = s;
}
public static implicit operator int(ImplicitConversionConflictWithLong v)
{
return v.s;
}
public static implicit operator long(ImplicitConversionConflictWithLong v)
{
return v.s;
}
}
public class ImplicitConversionConflictWithString
{
private readonly int s;
public ImplicitConversionConflictWithString(int s)
{
this.s = s;
}
public static implicit operator int(ImplicitConversionConflictWithString v)
{
return v.s;
}
public static implicit operator string(ImplicitConversionConflictWithString v)
{
return string.Empty;
}
}
public class ExplicitInt public class ExplicitInt
{ {
private readonly int s; private readonly int s;
@ -396,6 +436,62 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
} }
} }
public static void SwitchOverImplicitIntConflictLong(ImplicitConversionConflictWithLong i)
{
switch ((int)i)
{
case 0:
Console.WriteLine("zero");
break;
case 5:
Console.WriteLine("five");
break;
case 10:
Console.WriteLine("ten");
break;
case 15:
Console.WriteLine("fifteen");
break;
case 20:
Console.WriteLine("twenty");
break;
case 25:
Console.WriteLine("twenty-five");
break;
case 30:
Console.WriteLine("thirty");
break;
}
}
public static void SwitchOverImplicitIntConflictString(ImplicitConversionConflictWithString i)
{
switch ((string)i)
{
case "0":
Console.WriteLine("zero");
break;
case "5":
Console.WriteLine("five");
break;
case "10":
Console.WriteLine("ten");
break;
case "15":
Console.WriteLine("fifteen");
break;
case "20":
Console.WriteLine("twenty");
break;
case "25":
Console.WriteLine("twenty-five");
break;
case "30":
Console.WriteLine("thirty");
break;
}
}
// SwitchDetection.UseCSharpSwitch requires more complex heuristic to identify this when compiled with Roslyn // SwitchDetection.UseCSharpSwitch requires more complex heuristic to identify this when compiled with Roslyn
public static void CompactSwitchOverInt(int i) public static void CompactSwitchOverInt(int i)
{ {
@ -507,9 +603,7 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
public static string SwitchOverImplicitString(ImplicitString s) public static string SwitchOverImplicitString(ImplicitString s)
{ {
// we emit an explicit cast, because the rules used by the C# compiler are counter-intuitive: switch (s)
// The C# compiler does *not* take the type of the switch labels into account at all.
switch ((string)s)
{ {
case "First case": case "First case":
return "Text1"; return "Text1";

41
ICSharpCode.Decompiler/IL/Transforms/SwitchOnStringTransform.cs
Unescape View File

@ -1070,10 +1070,12 @@ namespace ICSharpCode.Decompiler.IL.Transforms
stringValues.Add((null, nullValueCaseBlock)); stringValues.Add((null, nullValueCaseBlock));
} }
// In newer Roslyn versions (>=3.7) the null check appears in the default case, not prior to the switch. // In newer Roslyn versions (>=3.7) the null check appears in the default case, not prior to the switch.
if (!stringValues.Any(pair => pair.Value == null) && IsNullCheckInDefaultBlock(ref exitOrDefaultBlock, switchValueLoad.Variable, out nullValueCaseBlock)) ILInstruction exitOrDefault = exitOrDefaultBlock;
if (!stringValues.Any(pair => pair.Value == null) && IsNullCheckInDefaultBlock(ref exitOrDefault, switchValueLoad.Variable, out nullValueCaseBlock))
{ {
stringValues.Add((null, nullValueCaseBlock)); stringValues.Add((null, nullValueCaseBlock));
} }
exitOrDefaultBlock = (Block)exitOrDefault;
context.Step(nameof(MatchRoslynSwitchOnString), switchValueLoad); context.Step(nameof(MatchRoslynSwitchOnString), switchValueLoad);
if (exitOrDefaultBlock != null) if (exitOrDefaultBlock != null)
@ -1176,7 +1178,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
{ {
if (!instructions[i + 1].MatchBranch(out var nextBlock)) if (!instructions[i + 1].MatchBranch(out var nextBlock))
return false; return false;
if (!exitBlockJump.MatchBranch(out nullCase)) if (!exitBlockJump.MatchBranch(out nullCase) && !exitBlockJump.MatchLeave(out _))
return false; return false;
// if (comp(ldloc switchValueVar == ldnull)) br ... // if (comp(ldloc switchValueVar == ldnull)) br ...
// br switchOnLengthBlock // br switchOnLengthBlock
@ -1202,7 +1204,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
switchValueVar = null; // will be extracted in MatchSwitchOnLengthBlock switchValueVar = null; // will be extracted in MatchSwitchOnLengthBlock
switchOnLengthBlockStartOffset = i; switchOnLengthBlockStartOffset = i;
} }
Block defaultCase = null; ILInstruction defaultCase = null;
if (!MatchSwitchOnLengthBlock(ref switchValueVar, switchOnLengthBlock, switchOnLengthBlockStartOffset, out var blocksByLength)) if (!MatchSwitchOnLengthBlock(ref switchValueVar, switchOnLengthBlock, switchOnLengthBlockStartOffset, out var blocksByLength))
return false; return false;
List<(string, ILInstruction)> stringValues = new(); List<(string, ILInstruction)> stringValues = new();
@ -1216,7 +1218,12 @@ namespace ICSharpCode.Decompiler.IL.Transforms
else else
{ {
int length = (int)b.Length.Intervals[0].Start; int length = (int)b.Length.Intervals[0].Start;
if (MatchSwitchOnCharBlock(b.TargetBlock, length, switchValueVar, out var mapping)) switch (b.TargetBlock)
{
case Leave leave:
break;
case Block targetBlock:
if (MatchSwitchOnCharBlock(targetBlock, length, switchValueVar, out var mapping))
{ {
foreach (var item in mapping) foreach (var item in mapping)
{ {
@ -1230,7 +1237,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
} }
} }
} }
else if (MatchRoslynCaseBlockHead(b.TargetBlock, switchValueVar, out var bodyOrLeave, out var exit, out string stringValue, out _)) else if (MatchRoslynCaseBlockHead(targetBlock, switchValueVar, out var bodyOrLeave, out var exit, out string stringValue, out _))
{ {
if (exit != defaultCase) if (exit != defaultCase)
return false; return false;
@ -1251,6 +1258,11 @@ namespace ICSharpCode.Decompiler.IL.Transforms
{ {
return false; return false;
} }
break;
default:
return false;
}
} }
} }
@ -1278,7 +1290,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
} }
var newSwitch = new SwitchInstruction(new StringToInt(new LdLoc(switchValueVar), values, switchValueVar.Type)); var newSwitch = new SwitchInstruction(new StringToInt(new LdLoc(switchValueVar), values, switchValueVar.Type));
newSwitch.Sections.AddRange(sections); newSwitch.Sections.AddRange(sections);
newSwitch.Sections.Add(new SwitchSection { Labels = defaultLabel, Body = new Branch(defaultCase) }); newSwitch.Sections.Add(new SwitchSection { Labels = defaultLabel, Body = defaultCase is Block b2 ? new Branch(b2) : defaultCase });
newSwitch.AddILRange(instructions[i]); newSwitch.AddILRange(instructions[i]);
if (nullCase != null) if (nullCase != null)
{ {
@ -1399,7 +1411,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
return results?.Count > 0; return results?.Count > 0;
} }
bool MatchSwitchOnLengthBlock(ref ILVariable switchValueVar, Block switchOnLengthBlock, int startOffset, out List<(LongSet Length, Block TargetBlock)> blocks) bool MatchSwitchOnLengthBlock(ref ILVariable switchValueVar, Block switchOnLengthBlock, int startOffset, out List<(LongSet Length, ILInstruction TargetBlock)> blocks)
{ {
blocks = null; blocks = null;
SwitchInstruction @switch; SwitchInstruction @switch;
@ -1482,17 +1494,18 @@ namespace ICSharpCode.Decompiler.IL.Transforms
{ {
if (section.HasNullLabel) if (section.HasNullLabel)
return false; return false;
if (!section.Body.MatchBranch(out var target)) if (!section.Body.MatchBranch(out var target) && !section.Body.MatchLeave(out _))
return false; return false;
ILInstruction targetInst = target ?? section.Body;
if (section.Labels.Count() != 1) if (section.Labels.Count() != 1)
{ {
defaultCase ??= target; defaultCase ??= targetInst;
if (defaultCase != target) if (defaultCase != targetInst)
return false; return false;
} }
else else
{ {
blocks.Add((section.Labels, target)); blocks.Add((section.Labels, targetInst));
} }
} }
return true; return true;
@ -1506,10 +1519,10 @@ namespace ICSharpCode.Decompiler.IL.Transforms
/// br newDefaultBlock /// br newDefaultBlock
/// } /// }
/// </summary> /// </summary>
private bool IsNullCheckInDefaultBlock(ref Block exitOrDefaultBlock, ILVariable switchVar, out Block nullValueCaseBlock) private bool IsNullCheckInDefaultBlock(ref ILInstruction exitOrDefault, ILVariable switchVar, out Block nullValueCaseBlock)
{ {
nullValueCaseBlock = null; nullValueCaseBlock = null;
if (exitOrDefaultBlock == null) if (exitOrDefault is not Block exitOrDefaultBlock)
return false; return false;
if (!exitOrDefaultBlock.Instructions[0].MatchIfInstruction(out var condition, out var thenBranch)) if (!exitOrDefaultBlock.Instructions[0].MatchIfInstruction(out var condition, out var thenBranch))
return false; return false;
@ -1523,7 +1536,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
return false; return false;
if (elseBlock.Parent != exitOrDefaultBlock.Parent) if (elseBlock.Parent != exitOrDefaultBlock.Parent)
return false; return false;
exitOrDefaultBlock = elseBlock; exitOrDefault = elseBlock;
return true; return true;
} }

Write Preview
Loading…
Cancel
Save