Invalid code is emitted for a user-defined conditional logical operator

[AlekseyTs]

public class Program
{
    static void Main()
    {
        _ = (Get1() && Get2());
    }

    static S1 Get1() => new S1();
    static S1 Get2() => new S1();
}

struct S1
{
    public static S1 operator &(S1 x, S1 y) => x;

    public static bool operator true(S1? x) => true;
    public static bool operator false(S1? x) => false;
}

PEVerify fails: [ : Program::Main][mdToken=0x6000003][offset 0x00000008][found value 'S1'][expected value 'System.Nullable`1[S1]'] Unexpected type on the stack.

IL:

    .method private hidebysig static 
        void Main () cil managed 
    {
        // Method begins at RVA 0x2050
        // Code size 30 (0x1e)
        .maxstack 2
        .locals init (
            [0] valuetype S1
        )

        IL_0000: nop
        IL_0001: call valuetype S1 Program::Get1()
        IL_0006: stloc.0
        IL_0007: ldloc.0
        IL_0008: call bool S1::op_False(valuetype [System.Runtime]System.Nullable`1<valuetype S1>)
        IL_000d: brtrue.s IL_001d

        IL_000f: ldloc.0
        IL_0010: call valuetype S1 Program::Get2()
        IL_0015: call valuetype S1 S1::op_BitwiseAnd(valuetype S1, valuetype S1)
        IL_001a: pop
        IL_001b: br.s IL_001d

        IL_001d: ret
    } // end of method Program::Main

[AlekseyTs]

Note that dynamic evaluation throws for a type like this:

public class Program
{
    static void Main()
    {
        _ = (dynamic)Get1() && (dynamic)Get2();
    }

    static S1 Get1() => new S1();
    static S1 Get2() => new S1();
}

struct S1
{
    public static S1 operator &(S1 x, S1 y) => x;

    public static bool operator true(S1? x) => true;
    public static bool operator false(S1? x) => false;
}

Observed:

System.ArgumentException: The user-defined operator method 'op_BitwiseAnd' for operator 'AndAlso' must have associated boolean True and False operators.
   at System.Linq.Expressions.Expression.ValidateUserDefinedConditionalLogicOperator(ExpressionType nodeType, Type left, Type right, MethodInfo method)
   at System.Linq.Expressions.Expression.AndAlso(Expression left, Expression right, MethodInfo method)

[AlekseyTs]

It looks like Linq expression trees do not support such logical operators:

public class Program
{
    static void Main()
    {
        System.Linq.Expressions.Expression<System.Func<S1>> ex = () => Get1() && Get2();
    }

    static S1 Get1() => new S1();
    static S1 Get2() => new S1();
}

struct S1
{
    public static S1 operator &(S1 x, S1 y) => x;

    public static bool operator true(S1? x) => true;
    public static bool operator false(S1? x) => false;
}

Observed:

System.ArgumentException: The user-defined operator method 'op_BitwiseAnd' for operator 'AndAlso' must have associated boolean True and False operators.
   at System.Linq.Expressions.Expression.ValidateUserDefinedConditionalLogicOperator(ExpressionType nodeType, Type left, Type right, MethodInfo method)
   at System.Linq.Expressions.Expression.AndAlso(Expression left, Expression right, MethodInfo method)
   at Program.Main()

[AlekseyTs]

Even lifted form isn't supported by expression trees:

public class Program
{
    static void Main()
    {
        System.Linq.Expressions.Expression<System.Func<S1?>> ex = () => Get1() && Get2();
    }

    static S1? Get1() => new S1();
    static S1? Get2() => new S1();
}

struct S1
{
    public static S1 operator &(S1 x, S1 y) => x;

    public static bool operator true(S1? x) => true;
    public static bool operator false(S1? x) => false;
}

Observed:

System.ArgumentException: The user-defined operator method 'op_BitwiseAnd' for operator 'AndAlso' must have associated boolean True and False operators.
   at System.Linq.Expressions.Expression.ValidateUserDefinedConditionalLogicOperator(ExpressionType nodeType, Type left, Type right, MethodInfo method)
   at System.Linq.Expressions.Expression.AndAlso(Expression left, Expression right, MethodInfo method)
   at Program.Main()

[AlekseyTs]

Not lifted form involving nullable operands is broken too:

public class Program
{
    static void Main()
    {
        System.Linq.Expressions.Expression<System.Func<S1?>> ex = () => Get1() && Get2();
    }

    static S1? Get1() => new S1();
    static S1? Get2() => new S1();
}

struct S1
{
    public static S1? operator &(S1? x, S1? y) => x;

    public static bool operator true(S1? x) => true;
    public static bool operator false(S1? x) => false;
}

Observed:

System.ArgumentException: The user-defined operator method 'op_BitwiseAnd' for operator 'AndAlso' must have associated boolean True and False operators.
   at System.Linq.Expressions.Expression.ValidateUserDefinedConditionalLogicOperator(ExpressionType nodeType, Type left, Type right, MethodInfo method)
   at System.Linq.Expressions.Expression.AndAlso(Expression left, Expression right, MethodInfo method)

[AlekseyTs]

Opened an issue for System.Linq.Expressions.Expression.ValidateUserDefinedConditionalLogicOperator exceptions - dotnet/runtime#115674