Collectives™ on Stack Overflow

Find centralized, trusted content and collaborate around the technologies you use most.

Teams

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

I recently installed the Visual Studio 11 Beta, and I'm trying to update an existing 4.0 project to use 4.5. In the program it compiles some dynamically generated code using CSharpCodeProvider .

/// <summary>
/// Compile and return a reference to the compiled assembly
/// </summary>
private Assembly Compile()
    var referencedDlls = new List<string>
        "mscorlib.dll",
        "System.dll",
        "System.Core.dll",
    referencedDlls.AddRange(RequiredReferences);
    var parameters = new CompilerParameters(
        assemblyNames: referencedDlls.ToArray(),
        outputName: GeneratedDllFileName,
        // only include debug information if we are currently debugging
        includeDebugInformation: Debugger.IsAttached);
    parameters.TreatWarningsAsErrors = false;
    parameters.WarningLevel = 0;
    parameters.GenerateExecutable = false;
    parameters.GenerateInMemory = false;
    parameters.CompilerOptions = "/optimize+ /platform:x64";
    string[] files = Directory.GetFiles(GenerationDirectory, "*.cs");
    var compiler = new CSharpCodeProvider(
        new Dictionary<string, string> { { "CompilerVersion", "v4.5" } });
    var results = compiler.CompileAssemblyFromFile(parameters, files);
    if (results.Errors.HasErrors)
        string firstError =
            string.Format("Compile error: {0}", results.Errors[0].ToString());
        throw new ApplicationException(firstError);
        return results.CompiledAssembly;
The problem comes when I changed the CompilerVersion from { "CompilerVersion", "v4.0" } to { "CompilerVersion", "v4.5" }
I now get an exception
  
Compiler executable file csc.exe cannot be found.
Is specifying CompilerVersion the wrong way to tell it to use 4.5? Will compiling it as v4.5 even make a difference since the code won't be using any new 4.5 specific features?
                I don't know if it is wrong to specify the compiler version like that but FWIW the compiler in .NET 4.5 is still version 4.0 according to the output.
– Brian Rasmussen
                Mar 6, 2012 at 20:48
                @abatishchev Since the code I'm compiling is all autogenerated there typically shouldn't be any errors unless the template is messed up, just returning the first prevents it from returning possibly thousands of errors, which would just result in a really long error email and not really be anymore helpful
– BrandonAGr
                Mar 7, 2012 at 17:45
It would have helped if you'd given us a short but complete program to demonstrate the problem, but I can verify that with "v4.0" it will work and compile async methods, assuming you're running on a machine with the VS11 beta installed.
Demonstration:
using System;
using System.Collections;
using System.Reflection;
using System.Collections.Generic;
using System.Diagnostics;
using Microsoft.CSharp;
using System.CodeDom.Compiler;
namespace Foo {}
class Program
    static void Main(string[] args)
        var referencedDll = new List<string>
            "mscorlib.dll",
            "System.dll",
            "System.Core.dll",
        var parameters = new CompilerParameters(
             assemblyNames: referencedDll.ToArray(),
             outputName: "foo.dll",
             includeDebugInformation: false)
            TreatWarningsAsErrors = true,
            // We don't want to be warned that we have no await!
            WarningLevel = 0,
            GenerateExecutable = false,
            GenerateInMemory = true
        var source = new[] { "class Test { static async void Foo() {}}" };
        var options = new Dictionary<string, string> {
             { "CompilerVersion", "v4.0" }
        var compiler = new CSharpCodeProvider(options);
        var results = compiler.CompileAssemblyFromSource(parameters, source);
        Console.WriteLine("Success? {0}", !results.Errors.HasErrors);
                Is it still version 4.0 because 4.5 is still in beta? Is the CompilerVersion going to be bumped in the final version? Also, is CompilerVersion the framework version or the C# compiler version?
– BFree
                Mar 6, 2012 at 21:16
                Thanks, it looks like since 4.5 installs on top of 4 and has the same version number I don't need to change the CompilerVersion in order to use 4.5
– BrandonAGr
                Mar 6, 2012 at 21:26
        
Thanks for contributing an answer to Stack Overflow!
Please be sure to answer the question. Provide details and share your research!
But avoid …
Asking for help, clarification, or responding to other answers.
Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.