port-commit.cs

// On CoreCLR side: git format-patch --stdout -1 {SHA-HASH} > d:\git\in.patch
// run tool
// On CoreRT side: git am d:\git\out.patch

/*
mapping.txt:

src/tools/crossgen2/Common/CommandLine src/Common/src/CommandLine
src/tools/crossgen2/Common/Compiler src/ILCompiler.Compiler/src/Compiler
src/tools/crossgen2/Common/JitInterface src/JitInterface/src
src/tools/crossgen2/Common/Internal src/Common/src/Internal
src/tools/crossgen2/Common/System src/Common/src/System
src/tools/crossgen2/Common/TypeSystem src/Common/src/TypeSystem
src/tools/crossgen2/jitinterface src/Native/jitinterface
*/

using System;
using System.Collections.Generic;
using System.IO;

namespace PortCommit
{
    class Program
    {
        static void Main(string[] args)
        {
            var map = new List<KeyValuePair<string, string>>();
            foreach (var line in File.ReadLines(@"d:\git\mapping.txt"))
            {
                string[] components = line.Split(' ');
                map.Add(new KeyValuePair<string, string>(components[0], components[1]));
            }

            using (var output = new StreamWriter(@"d:\git\out.patch"))
            {
                string[] lines = File.ReadAllLines(@"d:\git\in.patch");
                int index = 0;
                while (index < lines.Length)
                {
                    if (index != 0)
                        output.WriteLine();

                    string line = lines[index];
                    if (line.StartsWith("diff --git "))
                    {
                        while (!lines[++index].StartsWith("---")) ;

                        string fileName = lines[index].Substring(6);
                        if (fileName == "ev/null")
                        {
                            fileName = lines[index + 1].Substring(6);
                        }
                        
                        string replacement = null;
                        foreach (var m in map)
                        {
                            if (fileName.StartsWith(m.Key))
                            {
                                replacement = m.Value + fileName.Substring(m.Key.Length);
                                break;
                            }
                        }

                        if (replacement != null)
                        {
                            Console.WriteLine($"Porting file {fileName} to {replacement}");

                            output.WriteLine(lines[index - 2]); // diff --git
                            output.WriteLine(lines[index - 1]); // index
                            output.WriteLine("--- a/" + replacement);
                            index++;
                            if (lines[index] == "+++ /dev/null")
                                output.Write("+++ /dev/null");
                            else if (lines[index].Substring(6) != fileName)
                                throw new Exception("A and B mismatch");
                            else
                                output.Write("+++ b/" + replacement);
                            index++;
                        }
                        else
                        {
                            Console.WriteLine($"Skipping file {fileName}");

                            while (index < lines.Length && !lines[index].StartsWith("diff --git "))
                                index++;
                        }

                        continue;
                    }

                    output.Write(lines[index]);

                    index++;
                }
            }

        }
    }
}