FSharp Expression causes compiler results not consistent across grid

marklam

#10610 9 years ago 13 Jun 2017 14:03 UTC

Using an FSharp.Expr variable in a distributed test causes a warning because the compiler adds debug information containing file paths (NCrunch 3.8.0.3)

To reproduce: (F# 4.1, VS2017)
[list=1]

Create an F# class library project and add the NUnit 3.7 Nuget package

Use the following test implementation

namespace ExpressionTest

open NUnit.Framework

[<TestFixture>]
type Fixture1() = 
    [<Test>]
    member __.Test1 () = 
        let expression = <@ 99 @>
        Assert.AreEqual("Hello", "Hello")

The full path to the source file is stored in a byte array, and the length of the path affect the name (288Bytes here)

.class private abstract auto ansi sealed beforefieldinit '<PrivateImplementationDetails$ExpressionTest>'
       extends [mscorlib]System.Object
{
  .class explicit ansi sealed nested assembly beforefieldinit T1799_288Bytes@
         extends [mscorlib]System.ValueType
  {
    .pack 0
    .size 288
  } // end of class T1799_288Bytes@

} // end of class '<PrivateImplementationDetails$ExpressionTest>'

and also the call to deserialize the info (0x120 here)

      IL_0088:  ldc.i4     0x120
      IL_008d:  newarr     [mscorlib]System.Byte
      IL_0092:  dup
      IL_0093:  ldtoken    field valuetype '<PrivateImplementationDetails$ExpressionTest>'/T1799_288Bytes@ '<StartupCode$ExpressionTest>'.$Library1::field1800@
      IL_0098:  call       void [mscorlib]System.Runtime.CompilerServices.RuntimeHelpers::InitializeArray(class [mscorlib]System.Array,
                                                                                                          valuetype [mscorlib]System.RuntimeFieldHandle)
      IL_009d:  call       class [FSharp.Core]Microsoft.FSharp.Quotations.FSharpExpr [FSharp.Core]Microsoft.FSharp.Quotations.FSharpExpr::Deserialize40(class [mscorlib]System.Type,
                                                                                                                                                        class [mscorlib]System.Type[],
                                                                                                                                                        class [mscorlib]System.Type[],
                                                                                                                                                        class [FSharp.Core]Microsoft.FSharp.Quotations.FSharpExpr[],
                                                                                                                                                        uint8[])

Remco NCrunch Developer

#10611 9 years ago 14 Jun 2017 01:11 UTC

Hi, thanks for sharing this problem. I've been able to reproduce it as per your instructions.

I can confirm a fix for this will be in the next available build of NCrunch.

Remco NCrunch Developer

#10630 9 years ago 16 Jun 2017 04:04 UTC

marklam

#10635 9 years ago 16 Jun 2017 13:24 UTC

Thanks, but unfortunately, that doesn't fix this case:


namespace ExpressionTest

open NUnit.Framework
open System.IO

[<TestFixture>]
type Fixture1() = 
    [<Test>]
    member __.Test1 () = 
        let expression = (fun (x : Stream) -> <@ x.Close() @>)
        Assert.AreEqual("Hello", "Hello")

The differences I'm getting are in tests that use the Foq Nuget package, maybe my repro cases are too narrow.
A bigger set of examples are available in https://github.com/fsprojects/Foq/tree/master/Examples if that's helpful.

Remco NCrunch Developer

#10639 9 years ago 16 Jun 2017 23:42 UTC

Thanks, I'll take another look and will get back to you.

Remco NCrunch Developer

#10641 9 years ago 17 Jun 2017 03:33 UTC

It looks as though these expressions can have a broader footprint in the method structure than I originally thought. I have a broader fix in the pipe for this, I'll include this for you in the next dev build when this is available.

I recommend sticking with using an 'Impact analysis mode' of 'WatchText' for the time being if you need an immediate workaround for this problem.

marklam

#10811 9 years ago 21 Jul 2017 09:01 UTC

I haven't seen this happening with the newest build, looking good
Thanks!

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