Compile simple string

Question

Was just wondering if there are any built in functions in c++ OR c# that lets you use the compiler at runtime? Like for example if i want to translate:

!print "hello world";

into:

MessageBox.Show("hello world");

and then generate an exe which will then be able to display the above message? I've seen sample project around the web few years ago that did this but can't find it anymore.

Answer 1

It is possible using C#. Have a look at this Sample Project from the CodeProject.

Code Extract

private Assembly BuildAssembly(string code)
{
    Microsoft.CSharp.CSharpCodeProvider provider = new CSharpCodeProvider();
    ICodeCompiler compiler = provider.CreateCompiler();
    CompilerParameters compilerparams = new CompilerParameters();
    compilerparams.GenerateExecutable = false;
    compilerparams.GenerateInMemory = true;
    CompilerResults results = compiler.CompileAssemblyFromSource(compilerparams, code);
    if (results.Errors.HasErrors)
    {
       StringBuilder errors = new StringBuilder("Compiler Errors :\r\n");
       foreach (CompilerError error in results.Errors )
       {
            errors.AppendFormat("Line {0},{1}\t: {2}\n", error.Line, error.Column, error.ErrorText);
       }
       throw new Exception(errors.ToString());
    }
    else
    {
        return results.CompiledAssembly;
    }
}

public object ExecuteCode(string code, string namespacename, string classname, string functionname, bool isstatic, params object[] args)
{
    object returnval = null;
    Assembly asm = BuildAssembly(code);
    object instance = null;
    Type type = null;
    if (isstatic)
    {
        type = asm.GetType(namespacename + "." + classname);
    }
    else
    {
        instance = asm.CreateInstance(namespacename + "." + classname);
        type = instance.GetType();
    }
    MethodInfo method = type.GetMethod(functionname);
    returnval = method.Invoke(instance, args);
    return returnval;
}

Answer 2

In C++ you can't use the compiler at runtime but you can embed an interpreter in your project, like CINT.