List-patterns: add a few tests and add HasValidate flag

docs/contributing/Compiler Test Plan.md

@@ -93,7 +93,7 @@ This document provides guidance for thinking about language interactions and tes
 - Ref return, ref readonly return, ref ternary, ref readonly local, ref local re-assignment, ref foreach
 - `this = e;` in `struct` .ctor
 - Stackalloc (including initializers)
-- Patterns (constant, declaration, `var`, positional, property and extended property, discard, parenthesized, type, relational, `and`/`or`/`not`)
+- Patterns (constant, declaration, `var`, positional, property and extended property, discard, parenthesized, type, relational, `and`/`or`/`not`, list, slice)
 - Switch expressions
 - With expressions (on record classes and on value types)
 - Nullability annotations (`?`, attributes) and analysis

eng/test-build-correctness.ps1

@@ -53,6 +53,14 @@ try {
     }
   }
 
+  # Verify no TODO2 marker left
+  $prototypes = Get-ChildItem -Path src, eng, scripts -Exclude *.dll,*.exe,*.pdb,*.xlf,test-build-correctness.ps1 -Recurse | Select-String -Pattern 'TODO2' -CaseSensitive -SimpleMatch
+  if ($prototypes) {
+    Write-Host "Found TODO2 markers in source:"
+    Write-Host $prototypes
+    throw "TODO2 markers disallowed in compiler source"
+  }
+
   Write-Host "Building Roslyn"
   Exec-Block { & (Join-Path $PSScriptRoot "build.ps1") -restore -build -bootstrap -bootstrapConfiguration:Debug -ci:$ci -runAnalyzers:$true -configuration:$configuration -pack -binaryLog -useGlobalNuGetCache:$false -warnAsError:$true -properties "/p:RoslynEnforceCodeStyle=true"}
 

src/Compilers/CSharp/Portable/Binder/Binder_Patterns.cs

@@ -238,7 +238,6 @@ private BoundPattern BindSlicePattern(
                 pattern = BindPattern(node.Pattern, sliceType, GetValEscape(sliceType, inputValEscape), permitDesignations, hasErrors, diagnostics);
             }
 
-            Debug.Assert(GetIndexerOrImplicitIndexerSymbol(indexerAccess) is var _);
             return new BoundSlicePattern(node, pattern, indexerAccess, receiverPlaceholder, argumentPlaceholder, inputType: inputType, narrowedType: inputType, hasErrors);
         }
 
@@ -317,7 +316,6 @@ private BoundListPattern BindListPattern(
                 inputValEscape, permitDesignations, typeSyntax: null, diagnostics, ref hasErrors,
                 out Symbol? variableSymbol, out BoundExpression? variableAccess);
 
-            Debug.Assert(GetIndexerOrImplicitIndexerSymbol(indexerAccess) is var _);
             return new BoundListPattern(
                 syntax: node, subpatterns: subpatterns, hasSlice: sawSlice, lengthAccess: lengthAccess,
                 indexerAccess: indexerAccess, receiverPlaceholder, argumentPlaceholder, variable: variableSymbol,

src/Compilers/CSharp/Portable/Binder/DecisionDagBuilder_ListPatterns.cs

@@ -60,7 +60,6 @@ private Tests MakeTestsAndBindingsForListPattern(BoundDagTemp input, BoundListPa
                             Debug.Assert(slice.ReceiverPlaceholder is not null);
                             Debug.Assert(slice.ArgumentPlaceholder is not null);
 
-                            Debug.Assert(slice.IndexerAccess is BoundIndexerAccess or BoundImplicitIndexerAccess or BoundArrayAccess);
                             var sliceEvaluation = new BoundDagSliceEvaluation(slicePattern.Syntax, slicePattern.InputType, lengthTemp, startIndex: startIndex, endIndex: index,
                                 slice.IndexerAccess, slice.ReceiverPlaceholder, slice.ArgumentPlaceholder, input);
 
@@ -76,7 +75,6 @@ private Tests MakeTestsAndBindingsForListPattern(BoundDagTemp input, BoundListPa
                     Debug.Assert(list.ReceiverPlaceholder is not null);
                     Debug.Assert(list.ArgumentPlaceholder is not null);
 
-                    Debug.Assert(list.IndexerAccess is BoundIndexerAccess or BoundImplicitIndexerAccess or BoundArrayAccess);
                     var indexEvaluation = new BoundDagIndexerEvaluation(subpattern.Syntax, subpattern.InputType, lengthTemp, index++,
                         list.IndexerAccess, list.ReceiverPlaceholder, list.ArgumentPlaceholder, input);
 

src/Compilers/CSharp/Portable/BoundTree/BoundDagEvaluation.cs

@@ -108,6 +108,11 @@ public override bool IsEquivalentTo(BoundDagEvaluation obj)
             return base.IsEquivalentTo(obj) &&
                 this.Index == ((BoundDagIndexerEvaluation)obj).Index;
         }
+
+        private partial void Validate()
+        {
+            Debug.Assert(IndexerAccess is BoundIndexerAccess or BoundImplicitIndexerAccess or BoundArrayAccess);
+        }
     }
 
     partial class BoundDagSliceEvaluation
@@ -119,6 +124,11 @@ public override bool IsEquivalentTo(BoundDagEvaluation obj)
                 (BoundDagSliceEvaluation)obj is var e &&
                 this.StartIndex == e.StartIndex && this.EndIndex == e.EndIndex;
         }
+
+        private partial void Validate()
+        {
+            Debug.Assert(IndexerAccess is BoundIndexerAccess or BoundImplicitIndexerAccess or BoundArrayAccess);
+        }
     }
 
     partial class BoundDagAssignmentEvaluation

src/Compilers/CSharp/Portable/BoundTree/BoundIndexOrRangePatternIndexerAccess.cs → src/Compilers/CSharp/Portable/BoundTree/BoundImplicitIndexerAccess.cs

@@ -29,5 +29,11 @@ internal BoundExpression GetReceiver()
             Debug.Assert(receiver is not null);
             return receiver;
         }
+
+        private partial void Validate()
+        {
+            Debug.Assert(LengthOrCountAccess is BoundPropertyAccess or BoundLocal or BoundBadExpression);
+            Debug.Assert(IndexerOrSliceAccess is BoundIndexerAccess or BoundCall or BoundArrayAccess or BoundBadExpression);
+        }
     }
 }

src/Compilers/CSharp/Portable/BoundTree/BoundListPattern.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics;
+
+namespace Microsoft.CodeAnalysis.CSharp
+{
+    internal partial class BoundListPattern
+    {
+        private partial void Validate()
+        {
+            Debug.Assert(LengthAccess is null or BoundPropertyAccess or BoundBadExpression);
+            Debug.Assert(IndexerAccess is BoundIndexerAccess or BoundImplicitIndexerAccess or BoundArrayAccess or BoundBadExpression or BoundDynamicIndexerAccess);
+            Debug.Assert(Binder.GetIndexerOrImplicitIndexerSymbol(IndexerAccess) is var _);
+        }
+    }
+}

src/Compilers/CSharp/Portable/BoundTree/BoundNodes.xml

@@ -1519,7 +1519,7 @@
     <Field Name="Index" Type="int"/>
   </Node>
 
-  <Node Name="BoundDagIndexerEvaluation" Base="BoundDagEvaluation">
+  <Node Name="BoundDagIndexerEvaluation" Base="BoundDagEvaluation" HasValidate="true">
     <Field Name="IndexerType" Type="TypeSymbol"/>
     <Field Name="LengthTemp" Type="BoundDagTemp"/>
 
@@ -1539,7 +1539,7 @@
     <Field Name="ArgumentPlaceholder" Type="BoundListPatternIndexPlaceholder"/>
    </Node>
 
-  <Node Name="BoundDagSliceEvaluation" Base="BoundDagEvaluation">
+  <Node Name="BoundDagSliceEvaluation" Base="BoundDagEvaluation" HasValidate="true">
     <Field Name="SliceType" Type="TypeSymbol"/>
     <Field Name="LengthTemp" Type="BoundDagTemp"/>
     <Field Name="StartIndex" Type="int"/>
@@ -2066,7 +2066,7 @@
     <Field Name="OriginalIndexersOpt" Type="ImmutableArray&lt;PropertySymbol&gt;" Null="allow" SkipInNullabilityRewriter="true"/>
   </Node>
 
-  <Node Name="BoundImplicitIndexerAccess" Base="BoundExpression" SkipInNullabilityRewriter="true">
+  <Node Name="BoundImplicitIndexerAccess" Base="BoundExpression" SkipInNullabilityRewriter="true" HasValidate="true">
     <Field Name="Type" Type="TypeSymbol" Override="true" Null="disallow" />
 
     <!-- An expression with type Index or Range -->
@@ -2242,7 +2242,7 @@
     <Field Name="IsExplicitNotNullTest" Type="bool"/>
   </Node>
 
-  <Node Name="BoundListPattern" Base="BoundObjectPattern">
+  <Node Name="BoundListPattern" Base="BoundObjectPattern" HasValidate="true">
     <Field Name="Subpatterns" Type="ImmutableArray&lt;BoundPattern&gt;" Null="disallow"/>
     <Field Name="HasSlice" Type="bool"/>
     <Field Name="LengthAccess" Type="BoundExpression?" SkipInVisitor="true"/>
@@ -2260,7 +2260,7 @@
     <Field Name="ArgumentPlaceholder" Type="BoundListPatternIndexPlaceholder?" SkipInVisitor="true"/>
   </Node>
 
-  <Node Name="BoundSlicePattern" Base="BoundPattern">
+  <Node Name="BoundSlicePattern" Base="BoundPattern" HasValidate="true">
     <Field Name="Pattern" Type="BoundPattern?"/>
 
     <!--

src/Compilers/CSharp/Portable/BoundTree/BoundNodes.xsd

@@ -45,6 +45,7 @@
               <xs:attribute name="Name" type="xs:string" use="required" />
               <xs:attribute name="Base" type="xs:string" use="required" />
               <xs:attribute name="SkipInNullabilityRewriter" type="xs:boolean" use="optional" />
+              <xs:attribute name="HasValidate" type="xs:boolean" use="optional" />
             </xs:complexType>
           </xs:element>
         </xs:choice>

src/Compilers/CSharp/Portable/BoundTree/BoundSlicePattern.cs

@@ -0,0 +1,17 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics;
+
+namespace Microsoft.CodeAnalysis.CSharp
+{
+    internal partial class BoundSlicePattern
+    {
+        private partial void Validate()
+        {
+            Debug.Assert(IndexerAccess is BoundIndexerAccess or BoundImplicitIndexerAccess or BoundArrayAccess or BoundBadExpression or BoundDynamicIndexerAccess);
+            Debug.Assert(Binder.GetIndexerOrImplicitIndexerSymbol(IndexerAccess) is var _);
+        }
+    }
+}