Misc.

dotnet · Jan 17, 2021 · 686fcb8 · 686fcb8
1 parent c65c6e1
commit 686fcb8
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Showing 4 changed files with 40 additions and 15 deletions.
diff --git a/src/Compilers/CSharp/Portable/BoundTree/UnboundLambda.cs b/src/Compilers/CSharp/Portable/BoundTree/UnboundLambda.cs
@@ -126,8 +126,6 @@ public TypeWithAnnotations GetInferredReturnType(ConversionsBase conversions, Nu
  diagnostics,
  delegateInvokeMethodOpt: delegateType?.DelegateInvokeMethod,
  initialState: nullableState,
- analyzedNullabilityMapOpt: null,
- snapshotBuilderOpt: null,
  returnTypes);
  diagnostics.Free();
  var inferredReturnType = InferReturnType(returnTypes, node: this, Binder, delegateType, Symbol.IsAsync, conversions);

diff --git a/src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.Variables.cs b/src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.Variables.cs
@@ -131,7 +131,6 @@ private Variables(NextId nextId, int id, Variables? container, Symbol? symbol)
  Debug.Assert(container is null || container.Id < id);
  Debug.Assert(id < nextId.Value);
  _nextId = nextId;
- // PROTOTYPE: Handle > 64K nested methods (distinct ids). See NullableStateTooManyNestedFunctions().
  Id = id;
  Container = container;
  Symbol = symbol;
@@ -249,10 +248,10 @@ internal void GetMembers(ArrayBuilder<(VariableIdentifier, int)> builder, int co
  {
  (int id, int index) = DeconstructSlot(containingSlot);
  var variables = GetVariablesForId(id)!;
-
- for (index++; index < variables.Count; index++)
+ var variableBySlot = variables._variableBySlot;
+ for (index++; index < variableBySlot.Count; index++)
  {
- var variable = variables._variableBySlot[index];
+ var variable = variableBySlot[index];
  if (variable.ContainingSlot == containingSlot)
  {
  builder.Add((variable, ConstructSlot(id, index)));

diff --git a/src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs b/src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs
@@ -1293,8 +1293,6 @@ internal static void Analyze(
  DiagnosticBag diagnostics,
  MethodSymbol? delegateInvokeMethodOpt,
  VariableState initialState,
- ImmutableDictionary<BoundExpression, (NullabilityInfo, TypeSymbol?)>.Builder? analyzedNullabilityMapOpt,
- SnapshotManager.Builder? snapshotBuilderOpt,
  ArrayBuilder<(BoundReturnStatement, TypeWithAnnotations)>? returnTypesOpt)
  {
  var symbol = lambda.Symbol;
@@ -1310,12 +1308,12 @@ internal static void Analyze(
  conversions,
  variables,
  returnTypesOpt,
- analyzedNullabilityMapOpt,
- snapshotBuilderOpt);
+ analyzedNullabilityMapOpt: null,
+ snapshotBuilderOpt: null);
  try
  {
  var localState = LocalState.Create(initialState.VariableNullableStates).CreateNestedFunction(variables);
- Analyze(walker, symbol, diagnostics, localState, snapshotBuilderOpt);
+ Analyze(walker, symbol, diagnostics, localState, snapshotBuilderOpt: null);
  }
  finally
  {

diff --git a/src/Compilers/CSharp/Test/Semantic/Semantics/OverloadResolutionPerfTests.cs b/src/Compilers/CSharp/Test/Semantic/Semantics/OverloadResolutionPerfTests.cs
@@ -461,7 +461,35 @@ public void NullableStateLocalFunctions()
  }
 
  [ConditionalFact(typeof(NoIOperationValidation))]
- public void NullableStateTooManyLocals()
+ public void NullableStateTooManyLocals_01()
+ {
+ const int nLocals = 65536;
+
+ var builder = new StringBuilder();
+ builder.AppendLine("#pragma warning disable 168");
+ builder.AppendLine("#nullable enable");
+ builder.AppendLine("class Program");
+ builder.AppendLine("{");
+ builder.AppendLine(" static void F(object arg)");
+ builder.AppendLine(" {");
+ for (int i = 1; i < nLocals; i++)
+ {
+ builder.AppendLine($" object i{i};");
+ }
+ builder.AppendLine(" object i0 = arg;");
+ builder.AppendLine(" if (i0 == null) i0.ToString();");
+ builder.AppendLine(" }");
+ builder.AppendLine("}");
+
+ var source = builder.ToString();
+ var comp = CreateCompilation(source);
+ // No warning for i0.ToString() because the local is not tracked
+ // by the NullableWalker.Variables instance (too many locals).
+ comp.VerifyDiagnostics();
+ }
+
+ [ConditionalFact(typeof(NoIOperationValidation))]
+ public void NullableStateTooManyLocals_02()
  {
  const int nLocals = 65536;
 
@@ -482,7 +510,9 @@ public void NullableStateTooManyLocals()
 
  var source = builder.ToString();
  var comp = CreateCompilation(source);
- // PROTOTYPE: Perf: NullableWalker.Variables.GetMembers() is O(n^2).
+ // PROTOTYPE: Each assignment results in a call to NullableWalker.InheritDefaultState().
+ // InheritDefaultState() is O(n) where n is the number of locals, and since there is one
+ // assignment per local, the overall perf is O(n^2).
 #if false
  comp.VerifyDiagnostics(
  // (6,21): warning CS8600: Converting null literal or possible null value to non-nullable type.
@@ -494,7 +524,7 @@ public void NullableStateTooManyLocals()
  [ConditionalFact(typeof(NoIOperationValidation))]
  public void NullableStateTooManyNestedFunctions()
  {
- const int nFunctions = 65536;
+ const int nFunctions = 32768;
 
  var builder = new StringBuilder();
  builder.AppendLine("#nullable enable");
@@ -515,7 +545,7 @@ public void NullableStateTooManyNestedFunctions()
 
  var source = builder.ToString();
  var comp = CreateCompilation(source);
- // PROTOTYPE: Investigate performance.
+ // PROTOTYPE: Handle 32K nested methods (distinct ids) gracefully in NullableWalker.Variables.
 #if false
  comp.VerifyDiagnostics();
 #endif