What is SharpNative ?

SharpNative is a tool that generates Native Code (D, Soon C++11, Java and Swift) from C# leveraging Microsoft Roslyn to generate almost hand-written code the the target languages.

The idea is to maximize the cross-platform capabilities of C# without being tied to any vendor or platform. The Emphasis here is on Performance and Readability of the generated D Code. Comments are preserved as well.

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###Supported Output Languages The Compiler in its current state only supports D as the output language. (This is due to DMD being an extremely fast compiler, so testing features is fun)

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###Performance -- Results are very unscientific

The following are tests taken from CrossNet (one of the first C# to Native compiler efforts)

Machine:

-- Macbook Pro Retina (Mid 2012)

-- 2.6Ghz Intel Core i7

-- 16GB 1600 MHz DDR3

Some benchmarks on my Parallels Windows 8 VM: (3GB Ram, 3 Cores) using DMD with options -inline -release -m64 -O and .Net in release mode

|Type Of Test | C# Time (ms) | D Time (ms) | Speed Ratio (C#/D) | |-------------|:----------:|:---|------:| |NSieveTest| 18859 | 5450 | 3.46x | |MatrixTest(MultiDimensional)| 12359 | 22606 | 0.56x | |MatrixTest(Jagged)| 10156 | 2580 | 3.98x | |GCTest| 10657 | 57288 | 0.19x | |UnsafeTest| 32375 | 4752 | 6.81x | |HeapSortTest| 8671 | 3906 | 2.21x | |BinaryTreesTest| 12359 | 22635 | 0.55x | |CastsTest (using auto)| 6282 | 1784 | 3.52x | |CastsTest (using object)| 125 | 3211 | 0.04x | |EventsTest| 5985 | 6121 | 0.98x | |FannkuchTest| 1218 | 529 | 2.3x | |ForeachOnArrayTest| 34359 | 29358 | 1.17x | |InterfaceTest| 8297 | 4044 | 2.05x | |ListTest| 22422 | 5761 | 3.89x | |NestedLoopsTest| 33593 | 6466 | 5.19x | |PartialSumsTest| 4531 | 5518 | 0.82x | |RecursiveTest| 11406 | 3014 | 3.78x | |StringConcatenationTest| 63 | 147 | 0.43x | |VirtualTest| 8078 | 2784 | 2.9x | |Average | | | 2.34x |

Due to the produced binaries being native and better optimizations in the DMD, the generated binaries are generally much faster than their C# counterparts. Except when Garbage Collection is concerned, the D GC is much slower than that of .Net (Maybe we can port it to D). Also the current multidimensional array implementation seems lacking in performance.

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Example of Generated Code

C#:

using System;

class Primes
{
	public static void Main()
   {
       var len = 1000000; // This is a comment
       var primes = AddPrimes(len);
       Console.Write(primes);
   }

   private static int AddPrimes(int len)
   {
       var primes = 0;
       for (var i = 2; i < len; i++)
       {
           if (i%2 == 0)
               continue;
           var isPrime = true;
           for (var j = 2; j*j <= i; j++)
           {
               if (i%j == 0)
               {
                   isPrime = false;
                   break;
               }
           }
           if (isPrime)
               primes++;
       }
       return primes;
   }
   
}

D:

module CsRoot.Primes;
import System.Namespace;
import CsRoot.Namespace;

class Primes : NObject
{

    public static void Main()
    {
      int len = 1000000;
      // This is a comment
      int primes = AddPrimes(len);
      Console.Write(primes);
    }

    final static int AddPrimes(int len)
    {
      int primes = 0;
      
      for (int i = 2;i<len;i++)
      {
        if(i%2==0)
        {
          continue;
        }
        bool isPrime = true;
        
        for (int j = 2;j*j<=i;j++)
        {
          if(i%j==0)
          {
            isPrime=false;
            break;
          }
        }
        if(isPrime)
        {
          primes++;
        }
      }
      return primes;
    }

  public override String ToString()
  {
    return GetType().FullName;
  }

  public override Type GetType()
  {
    return __TypeOf!(typeof(this));
  }
}

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###Documentation Unfortunately this is all the documentation the transpiler has at the moment.

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Feature List (Incomplete):

• What works:
• Basic PInvoke including marshalling
• Arrays including initializers
• Fields/ Properties/Methods with correct hiding semantics
• Properties
• String
• Int/Double/Bool
• Classes and Polymorphism … we follow C# model
• Some benchmarks - basic linpack, fannkuch, nbody
• Modules/Namespaces
• Enum - no enum.Parse support yet though
• Iterators are as .Net use enumerators etc … switching arrays to use simple for loop though for performance improvement
• Constructors/Overloads/Base Class calls
• Static Variables/Members/Properties
• Basic System.Math, more implementations required though
• Extension Methods
• Operator Overloading
• Indexers
• Anonymous Classes
• Generics … All current test cases work
• Boxed structs and interface casting for them
• Inner Classes in the form of OuterClass_InnerClass
• Static Constructors
• Explicit Interfaces
• Implicit and Explicit Cast Operators
• String switch … dlang supports this natively :)
• String.Format .. though implementation is very basic
• C# multi dimensional arrays work correctly (even with multi dim syntax :) )
• Delegates work including multicast (Native delegates through P/Invoke work too)
• Events work as expected … though a bit slower than C#(mono)
• Object initializers work as a chain of lambda expressions
• Generic Virtual Methods
• Basic Reflection of Methods, Fields and Properties, IndexerProperties are not yet supported as are Generic Methods ... for now.
• Iterators and Yield using code from WootzJS, a fiber implementation exists but it crashes on DMD 2.066 Windows 64-bit

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###Requirements -- Testing -- Microsoft .Net 4.0 / Mono 3.6 and above.

-- Windows 7 or Later ( The CLI Interface works on Linux and OSX)

-- A Working D Installation (LDC,DMD or GDC)

###Requirements -- Development All requirements mentioned above and:

-- Visual Studio 2013 or above

-- Visual D

###Usage If you are using the GUI interface(windows) note that DMD should be installed in "C:\\D\\dmd2\\windows\\bin\\" For the CLI interface the driver can be invoked in the following manner:

mono ./SharpNative.exe /compiler:pathtodcompiler /dcorlib:/**pathtodcorlib** /source:"pathtosourcefile" /outputtype:exe /dstdlib:pathtophobos /compileroptions:"compileroptions"

where:

-- pathtodcompiler is the path to a d compiler e.g. /usr/local/bin/ldc on mac osx

-- pathtodcorlib is the path to the included basic corlib e.g. /Projects/SharpNative/DCorlib

-- pathtosourcefile is the path to the test source file in C#

--pathtophobos is the location of phobos in your installation e.g. /usr/local/Cellar/ldc/0.15.0/include/d

--compileroptions are the compiler options to pass to dmd/ldc/gdc e.g. -inline -release -m64 -O5 -oq

What Doesn’t Work: (Also Incomplete)

• Right now compiler does not do any optimizations like final, in, out @pure etc …
• Async/Await - Working on an implementation
• Query Expression Syntax for LINQ and Expression Trees
• Structs FieldLayout implementation is currently wrong ... to mimic C# a new design is needed.