Unexpected value QueryClause of type Microsoft.CodeAnalysis.CSharp.BoundKind

[KyouyamaKazusa0805]

Version Used:

VS 17.12 p2

Steps to Reproduce:

Type code using customized Select method (but use query syntax to reproduce) and collection expression spread operation:

using System.Runtime.CompilerServices;

CustomizedCollection c = [.. from element in returnArray() select element / 9];
static int[] returnArray() => throw null!;

[CollectionBuilder(typeof(CustomizedCollection), nameof(Create))]
struct CustomizedCollection
{
    public void Add(int variable) => throw null!;
    public IEnumerator<int> GetEnumerator() => throw null!;
    public static CustomizedCollection Create(ReadOnlySpan<int> values) => throw null!;
}

static class Extensions
{
    public static ReadOnlySpan<TResult> Select<T, TResult>(this T[] array, Func<T, TResult> selector)
        => throw null!;
}

I'm not sure whether the failure should use spread operation, but my environment can reproduce by using this; one necessary condition is to use LINQ query syntax.

If query syntax is replaced with equivalent method invocation, the code will be fine to compile:

// Okay
CustomizedCollection c = [.. returnArray().Select(element => element / 9)];

// Bad
CustomizedCollection c = [.. from element in returnArray() select element / 9];

Diagnostic Id:

None

Expected Behavior:

Fine to compile.

Actual Behavior:

"csc.exe" exited with code -2146232797.

Failed message:

Application: csc.exe
Framework Version: v4.0.30319
Description: The application requested process termination through System.Environment.FailFast(string message).
Message: System.InvalidOperationException: Unexpected value 'QueryClause' of type 'Microsoft.CodeAnalysis.CSharp.BoundKind'
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpressionCore(BoundExpression expression, Boolean used)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpression(BoundExpression expression, Boolean used)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitArguments(ImmutableArray`1 arguments, ImmutableArray`1 parameters, ImmutableArray`1 argRefKindsOpt)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStaticCallExpression(BoundCall call, UseKind useKind)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpression(BoundExpression expression, Boolean used)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitAssignmentExpression(BoundAssignmentOperator assignmentOperator, UseKind useKind)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpressionCoreWithStackGuard(BoundExpression expression, Boolean used)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpression(BoundExpression expression, Boolean used)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatement(BoundStatement statement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatementAndCountInstructions(BoundStatement statement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitSequencePointStatement(BoundSequencePointWithSpan node)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatement(BoundStatement statement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatements(ImmutableArray`1 statements)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitUninstrumentedBlock(BoundBlock block)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatement(BoundStatement statement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatementList(BoundStatementList list)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatement(BoundStatement statement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.GenerateImpl()
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.GenerateMethodBody(PEModuleBuilder moduleBuilder, MethodSymbol method, Int32 methodOrdinal, BoundStatement block, ImmutableArray`1 lambdaDebugInfo, ImmutableArray`1 orderedLambdaRuntimeRudeEdits, ImmutableArray`1 closureDebugInfo, ImmutableArray`1 stateMachineStateDebugInfos, StateMachineTypeSymbol stateMachineTypeOpt, VariableSlotAllocator variableSlotAllocatorOpt, BindingDiagnosticBag diagnostics, DebugDocumentProvider debugDocumentProvider, ImportChain importChainOpt, Boolean emittingPdb, ImmutableArray`1 codeCoverageSpans, AsyncForwardEntryPoint entryPointOpt)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.CompileMethod(MethodSymbol methodSymbol, Int32 methodOrdinal, ProcessedFieldInitializers& processedInitializers, SynthesizedSubmissionFields previousSubmissionFields, TypeCompilationState compilationState)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.CompileNamedType(NamedTypeSymbol containingType)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.<>c__DisplayClass25_0.<CompileNamedTypeAsync>b__0()
Stack:
   at System.Environment.FailFast(System.String, System.Exception)
   at Microsoft.CodeAnalysis.FailFast.OnFatalException(System.Exception)
   at Microsoft.CodeAnalysis.ErrorReporting.FatalError.Report(System.Exception, Microsoft.CodeAnalysis.ErrorReporting.ErrorSeverity, Boolean)
   at Microsoft.CodeAnalysis.ErrorReporting.FatalError.ReportAndPropagateUnlessCanceled(System.Exception, Microsoft.CodeAnalysis.ErrorReporting.ErrorSeverity)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler+<>c__DisplayClass25_0.<CompileNamedTypeAsync>b__0()
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpressionCore(Microsoft.CodeAnalysis.CSharp.BoundExpression, Boolean)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpression(Microsoft.CodeAnalysis.CSharp.BoundExpression, Boolean)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitArguments(System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CSharp.BoundExpression>, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CSharp.Symbols.ParameterSymbol>, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.RefKind>)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStaticCallExpression(Microsoft.CodeAnalysis.CSharp.BoundCall, UseKind)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpression(Microsoft.CodeAnalysis.CSharp.BoundExpression, Boolean)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitAssignmentExpression(Microsoft.CodeAnalysis.CSharp.BoundAssignmentOperator, UseKind)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpressionCoreWithStackGuard(Microsoft.CodeAnalysis.CSharp.BoundExpression, Boolean)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitExpression(Microsoft.CodeAnalysis.CSharp.BoundExpression, Boolean)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatement(Microsoft.CodeAnalysis.CSharp.BoundStatement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatementAndCountInstructions(Microsoft.CodeAnalysis.CSharp.BoundStatement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitSequencePointStatement(Microsoft.CodeAnalysis.CSharp.BoundSequencePointWithSpan)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatement(Microsoft.CodeAnalysis.CSharp.BoundStatement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatements(System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CSharp.BoundStatement>)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitUninstrumentedBlock(Microsoft.CodeAnalysis.CSharp.BoundBlock)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatement(Microsoft.CodeAnalysis.CSharp.BoundStatement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatementList(Microsoft.CodeAnalysis.CSharp.BoundStatementList)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.EmitStatement(Microsoft.CodeAnalysis.CSharp.BoundStatement)
   at Microsoft.CodeAnalysis.CSharp.CodeGen.CodeGenerator.GenerateImpl()
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.GenerateMethodBody(Microsoft.CodeAnalysis.CSharp.Emit.PEModuleBuilder, Microsoft.CodeAnalysis.CSharp.Symbols.MethodSymbol, Int32, Microsoft.CodeAnalysis.CSharp.BoundStatement, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.Emit.EncLambdaInfo>, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CodeGen.LambdaRuntimeRudeEditInfo>, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.Emit.EncClosureInfo>, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CodeGen.StateMachineStateDebugInfo>, Microsoft.CodeAnalysis.CSharp.StateMachineTypeSymbol, Microsoft.CodeAnalysis.CodeGen.VariableSlotAllocator, Microsoft.CodeAnalysis.CSharp.BindingDiagnosticBag, Microsoft.CodeAnalysis.CodeGen.DebugDocumentProvider, Microsoft.CodeAnalysis.CSharp.ImportChain, Boolean, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CodeGen.SourceSpan>, AsyncForwardEntryPoint)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.CompileMethod(Microsoft.CodeAnalysis.CSharp.Symbols.MethodSymbol, Int32, ProcessedFieldInitializers ByRef, Microsoft.CodeAnalysis.CSharp.SynthesizedSubmissionFields, Microsoft.CodeAnalysis.CSharp.TypeCompilationState)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.CompileNamedType(Microsoft.CodeAnalysis.CSharp.Symbols.NamedTypeSymbol)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler+<>c__DisplayClass25_0.<CompileNamedTypeAsync>b__0()
   at Roslyn.Utilities.UICultureUtilities+<>c__DisplayClass5_0.<WithCurrentUICulture>b__0()
   at System.Threading.Tasks.Task.Execute()
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(System.Threading.Tasks.Task ByRef)
   at System.Threading.Tasks.Task.ExecuteEntry(Boolean)
   at System.Threading.ThreadPoolWorkQueue.Dispatch()

[huoyaoyuan]

Oh, I've referenced this syntax multiple times (dotnet/csharplang#7634 (comment)) without verifying it actually works. Perhaps it worked in previous versions.

[KyouyamaKazusa0805]

Oh, I've referenced this syntax multiple times (dotnet/csharplang#7634 (comment)) without verifying it actually works. Perhaps it worked in previous versions.

@huoyaoyuan It indeed works in previous versions, but it fails from 17.12 as beginning version.

[AlekseyTs]

This looks like a regression from #73102