Is there a way to run ILASM from F# code?

Question

I am making a compiler from (a small subset of) Java to CIL (MSIL) in F# and I was thinking about writing some unit tests for the actual compilation part. Is there a way I could run ilasm on the generated IL code and the run the .exe file from a unit test? I am using NUnit.

Concretely, is there a way to do the following?

[<Test>]
member this.TestSimpleMain () = 
            let fileName = __SOURCE_DIRECTORY__.Replace("code", "examples\SimpleMain.cil")
            // run ilasm on fileName -> should produce ...\SimpleMain.exe
            let actualResult = // run ...\SimpleMain.exe file
            Assert.That(actualResult , Is.EqualTo("Program returned value 5!")))

You can always use `Reflection.Emit`. Also, in the F# source, there are a bunch of IL compare tests, you could copy that part of the testing framework. — Abel, Aug 11 '20 at 21:43
IIRC F# compiler does use ILDASM to decompile the binaries and then verifies it matches the expecations. — Just another metaprogrammer, Aug 13 '20 at 06:26

score 1 · Accepted Answer · answered Aug 24 '20 at 12:20

If you want to use ilasm make sure you create SimpleMain.cil in IL assembly format (text representation of CIL). Then you should create PE (exe/dll) file from your il file.

here is an example for the nunit test with output and exit code verification:

[<Test>]
member this.TestSimpleMain() =
    // Code that creates SimpleMain.il

    let p1 = new System.Diagnostics.Process()
    p1.StartInfo.FileName <- "C:/Windows/Microsoft.NET/Framework64/v4.0.30319/ilasm.exe"
    p1.StartInfo.Arguments <- "SimpleMain.il /exe /output=SimpleMain.exe"
    p1.Start()
    p1.WaitForExit()

    let p2 = new System.Diagnostics.Process()
    p2.StartInfo.FileName <- "SimpleMain.exe"
    p2.StartInfo.RedirectStandardOutput <- true // For output verification
    p2.Start()
    p2.WaitForExit()

    let resultA = p2.ExitCode // For exit code verification
    let resultB = p2.StandardOutput.ReadToEnd() // For output verification
    Assert.That(result, Is.EqualTo(expectedResult))

It doesn't work unless p2 has an explicit setting of UsesShellExecute to false — AndreiXwe, Aug 24 '20 at 19:29

Is there a way to run ILASM from F# code?

1 Answers1