A tool for converting C to Go.

I created this project as a proof of concept. It is written in python and uses the python clang bindings to do all of the hard work.

Let's use prime.c:

#include <stdio.h>
 
int main()
{
   int n, c;
 
   printf("Enter a number\n");
   scanf("%d", &n);
 
   if ( n == 2 )
      printf("Prime number.\n");
   else
   {
       for ( c = 2 ; c <= n - 1 ; c++ )
       {
           if ( n % c == 0 )
              break;
       }
       if ( c != n )
          printf("Not prime.\n");
       else
          printf("Prime number.\n");
   }
   return 0;
}

python c2go.py tests/prime.c

package main

import (
    "fmt"
)

// ... lots of system types in Go removed for brevity.

func main() {
    var n int
    var c int
    fmt.Printf("Enter a number\n")
    fmt.Scanf("%d", &n)
    if n == 2 {
        fmt.Printf("Prime number.\n")
    } else {
        for c = 2; c <= n - 1; c += 1 {
            if n % c == 0 {
                break
            }
        }
        if c != n {
            fmt.Printf("Not prime.\n")
        } else {
            fmt.Printf("Prime number.\n")
        }
    }
    return
}

This is the process:

1. The C code is preprocessed with clang. This generates a larger file, but removes all the platform specific directives and macros.

2. The new file is parsed with the clang AST which has bindings with python. Apart from just parsing the C and exposing an AST, the AST contains all of the resolved information that a compiler would need. This means that the code must compile successfully under clang for the AST to also be usable.

3. Since we have all the types in the AST it's just a matter of traversing the tree is a semi-intelligent way and producing Go.

Testing is done with a set of integrations tests in the form of complete C programs that can be found in the tests directory.

For each of those files:

1. Clang compiles the C to a binary as normal.
2. c2go converts the C file to Go.
3. The Go is built to produce another binary.
4. Both binaries are executed and the output is compared. All C files will contain some output.

The test suite is run with run-tests.sh.

As I said it is just a proof of concept (sorry for all the hacky Python).

Contributing is done with pull requests. If you're looking for where to start I can suggesting finding a simple C program (like the other examples) that does not successful translate to Go and fixing up the Python so that it does.