16.7 causing wpf project to fail with `"csc.exe" exited with code -2146232797`

Version Used: 16.7 (was working fine in 16.6.x)

Steps to Reproduce:

Build the project. The only message I see is

       e.targets(70,5): error MSB6006: "csc.exe" exited with code -2146232797. [C:\path\to\source\Wpf.project\Wpf.project_0egzionw_wpftmp.csproj]

There is a stack trace in the event viewer:

Framework Version: v4.0.30319
Description: The application requested process termination through System.Environment.FailFast(string message).
Message: System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.DecisionDagRewriter.WhenClauseMightAssignPatternVariableWalker.MethodMayMutateReceiver(BoundExpression receiver, MethodSymbol method)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.DecisionDagRewriter.WhenClauseMightAssignPatternVariableWalker.VisitPropertyAccess(BoundPropertyAccess node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32& recursionDepth, BoundExpression node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalker.VisitNameOfOperator(BoundNameOfOperator node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32& recursionDepth, BoundExpression node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalker.VisitBinaryOperator(BoundBinaryOperator node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.VisitExpressionWithStackGuard(BoundExpression node)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32& recursionDepth, BoundExpression node)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.DecisionDagRewriter.WhenClauseMightAssignPatternVariableWalker.MightAssignSomething(BoundExpression expr)
   at System.Linq.ImmutableArrayExtensions.Any[T](ImmutableArray`1 immutableArray, Func`2 predicate)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.DecisionDagRewriter.ShareTempsIfPossibleAndEvaluateInput(BoundDecisionDag decisionDag, BoundExpression loweredSwitchGoverningExpression, ArrayBuilder`1 result, BoundExpression& savedInputExpression)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.SwitchStatementLocalRewriter.LowerSwitchStatement(BoundSwitchStatement node)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.SwitchStatementLocalRewriter.Rewrite(LocalRewriter localRewriter, BoundSwitchStatement node)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitStatement(BoundStatement node)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitPossibleUsingDeclaration(BoundStatement node, ImmutableArray`1 statements, Int32 statementIndex, Boolean& replacedLocalDeclarations)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitStatementSubList(ArrayBuilder`1 builder, ImmutableArray`1 statements, Int32 startIndex)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitBlock(BoundBlock node)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitStatement(BoundStatement node)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.Rewrite(CSharpCompilation compilation, MethodSymbol method, Int32 methodOrdinal, NamedTypeSymbol containingType, BoundStatement statement, TypeCompilationState compilationState, SynthesizedSubmissionFields previousSubmissionFields, Boolean allowOmissionOfConditionalCalls, Boolean instrumentForDynamicAnalysis, ImmutableArray`1& dynamicAnalysisSpans, DebugDocumentProvider debugDocumentProvider, DiagnosticBag diagnostics, Boolean& sawLambdas, Boolean& sawLocalFunctions, Boolean& sawAwaitInExceptionHandler)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.LowerBodyOrInitializer(MethodSymbol method, Int32 methodOrdinal, BoundStatement body, SynthesizedSubmissionFields previousSubmissionFields, TypeCompilationState compilationState, Boolean instrumentForDynamicAnalysis, DebugDocumentProvider debugDocumentProvider, ImmutableArray`1& dynamicAnalysisSpans, DiagnosticBag diagnostics, VariableSlotAllocator& lazyVariableSlotAllocator, ArrayBuilder`1 lambdaDebugInfoBuilder, ArrayBuilder`1 closureDebugInfoBuilder, StateMachineTypeSymbol& stateMachineTypeOpt)
   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__DisplayClass22_0.<CompileNamedTypeAsync>b__0()
Stack:
   at System.Environment.FailFast(System.String, System.Exception)
   at Microsoft.CodeAnalysis.FailFast.OnFatalException(System.Exception)
   at Microsoft.CodeAnalysis.FatalError.ReportUnlessCanceled(System.Exception)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler+<>c__DisplayClass22_0.<CompileNamedTypeAsync>b__0()
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter+DecisionDagRewriter+WhenClauseMightAssignPatternVariableWalker.MethodMayMutateReceiver(Microsoft.CodeAnalysis.CSharp.BoundExpression, Microsoft.CodeAnalysis.CSharp.Symbols.MethodSymbol)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter+DecisionDagRewriter+WhenClauseMightAssignPatternVariableWalker.VisitPropertyAccess(Microsoft.CodeAnalysis.CSharp.BoundPropertyAccess)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(Microsoft.CodeAnalysis.CSharp.BoundExpression)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32 ByRef, Microsoft.CodeAnalysis.CSharp.BoundExpression)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalker.VisitNameOfOperator(Microsoft.CodeAnalysis.CSharp.BoundNameOfOperator)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(Microsoft.CodeAnalysis.CSharp.BoundExpression)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32 ByRef, Microsoft.CodeAnalysis.CSharp.BoundExpression)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalker.VisitBinaryOperator(Microsoft.CodeAnalysis.CSharp.BoundBinaryOperator)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeWalkerWithStackGuard.VisitExpressionWithoutStackGuard(Microsoft.CodeAnalysis.CSharp.BoundExpression)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.VisitExpressionWithStackGuard(Microsoft.CodeAnalysis.CSharp.BoundExpression)
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.VisitExpressionWithStackGuard(Int32 ByRef, Microsoft.CodeAnalysis.CSharp.BoundExpression)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter+DecisionDagRewriter+WhenClauseMightAssignPatternVariableWalker.MightAssignSomething(Microsoft.CodeAnalysis.CSharp.BoundExpression)
   at System.Linq.ImmutableArrayExtensions.Any[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]](System.Collections.Immutable.ImmutableArray`1<System.__Canon>, System.Func`2<System.__Canon,Boolean>)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter+DecisionDagRewriter.ShareTempsIfPossibleAndEvaluateInput(Microsoft.CodeAnalysis.CSharp.BoundDecisionDag, Microsoft.CodeAnalysis.CSharp.BoundExpression, Microsoft.CodeAnalysis.PooledObjects.ArrayBuilder`1<Microsoft.CodeAnalysis.CSharp.BoundStatement>, Microsoft.CodeAnalysis.CSharp.BoundExpression ByRef)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter+SwitchStatementLocalRewriter.LowerSwitchStatement(Microsoft.CodeAnalysis.CSharp.BoundSwitchStatement)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter+SwitchStatementLocalRewriter.Rewrite(Microsoft.CodeAnalysis.CSharp.LocalRewriter, Microsoft.CodeAnalysis.CSharp.BoundSwitchStatement)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitStatement(Microsoft.CodeAnalysis.CSharp.BoundStatement)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitPossibleUsingDeclaration(Microsoft.CodeAnalysis.CSharp.BoundStatement, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CSharp.BoundStatement>, Int32, Boolean ByRef)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitStatementSubList(Microsoft.CodeAnalysis.PooledObjects.ArrayBuilder`1<Microsoft.CodeAnalysis.CSharp.BoundStatement>, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CSharp.BoundStatement>, Int32)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitBlock(Microsoft.CodeAnalysis.CSharp.BoundBlock)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.VisitStatement(Microsoft.CodeAnalysis.CSharp.BoundStatement)
   at Microsoft.CodeAnalysis.CSharp.LocalRewriter.Rewrite(Microsoft.CodeAnalysis.CSharp.CSharpCompilation, Microsoft.CodeAnalysis.CSharp.Symbols.MethodSymbol, Int32, Microsoft.CodeAnalysis.CSharp.Symbols.NamedTypeSymbol, Microsoft.CodeAnalysis.CSharp.BoundStatement, Microsoft.CodeAnalysis.CSharp.TypeCompilationState, Microsoft.CodeAnalysis.CSharp.SynthesizedSubmissionFields, Boolean, Boolean, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CodeGen.SourceSpan> ByRef, Microsoft.CodeAnalysis.CodeGen.DebugDocumentProvider, Microsoft.CodeAnalysis.DiagnosticBag, Boolean ByRef, Boolean ByRef, Boolean ByRef)
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.LowerBodyOrInitializer(Microsoft.CodeAnalysis.CSharp.Symbols.MethodSymbol, Int32, Microsoft.CodeAnalysis.CSharp.BoundStatement, Microsoft.CodeAnalysis.CSharp.SynthesizedSubmissionFields, Microsoft.CodeAnalysis.CSharp.TypeCompilationState, Boolean, Microsoft.CodeAnalysis.CodeGen.DebugDocumentProvider, System.Collections.Immutable.ImmutableArray`1<Microsoft.CodeAnalysis.CodeGen.SourceSpan> ByRef, Microsoft.CodeAnalysis.DiagnosticBag, Microsoft.CodeAnalysis.CodeGen.VariableSlotAllocator ByRef, Microsoft.CodeAnalysis.PooledObjects.ArrayBuilder`1<Microsoft.CodeAnalysis.CodeGen.LambdaDebugInfo>, Microsoft.CodeAnalysis.PooledObjects.ArrayBuilder`1<Microsoft.CodeAnalysis.CodeGen.ClosureDebugInfo>, Microsoft.CodeAnalysis.CSharp.StateMachineTypeSymbol ByRef)
   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__DisplayClass22_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()

I tried to get the jit-debugger attached to the csc.exe, but I was unable to (don’t know how). I followed the advise here: https://docs.microsoft.com/en-us/visualstudio/debugger/debug-using-the-just-in-time-debugger?view=vs-2019#jit_errors but I couldn’t get the jit-debugger working.

Expected Behavior: Project compiles

Actual Behavior: Project fails to build with the error:

       e.targets(70,5): error MSB6006: "csc.exe" exited with code -2146232797. [C:\Users\Chase.Wallis\source\Product\Co
       mmon\AdminArsenal.Product.Wpf\AdminArsenal.Product.Wpf_0egzionw_wpftmp.csproj]```

[chasewallis]

This commit 52be8a33ec3fadc5511d46d5b1726bead24c270a didn’t do a null check for receiver.

private static bool MethodMayMutateReceiver(BoundExpression receiver, MethodSymbol method)
{
  return
     method != null &&
     !method.IsStatic &&
     !method.IsEffectivelyReadOnly &&
     receiver.Type?.IsReferenceType == false &&
     // methods of primitive types do not mutate their receiver
     method.ContainingType.SpecialType.IsPrimitiveRecursiveStruct();
}

[gafter]

Repro here:

struct Outer
{
    struct S
    {
        static void M(string q)
        {
            S s = new S();
            System.Console.Write(s switch
            {
                { P: 1 } when nameof(Q) == q => 1,
                { P: 2 } => 2,
                _ => 3,
            });
        }

        int P => 1;
    }

    public int Q => 1;
}