protobuf/src/ProtoGen/ProgramPreprocess.cs

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

namespace Google.ProtocolBuffers.ProtoGen
{
	/// <summary>
	/// Preprocesses any input files with an extension of '.proto' by running protoc.exe.  If arguments
	/// are supplied with '--' prefix they are provided to protoc.exe, otherwise they are assumed to
	/// be used for ProtoGen.exe which is run on the resulting output proto buffer.  If the option
	/// --descriptor_set_out= is specified the proto buffer file is kept, otherwise it will be removed
	/// after code generation.
	/// </summary>
    internal class ProgramPreprocess
    {
        static int Main(string[] args)
        {
            try
			{
				return Environment.ExitCode = Run(args);
			}
			catch (Exception ex)
			{
				Console.Error.WriteLine(ex);
				return Environment.ExitCode = 2;
			}
        }
		
		internal static int Run(params string[] args)
		{
			bool deleteFile = false;
            string tempFile = null;
            int result = 1;
        	bool doHelp = args.Length == 0;
            try
            {
                List<string> protocArgs = new List<string>();
                List<string> protoGenArgs = new List<string>();

                foreach (string arg in args)
				{
					doHelp |= StringComparer.OrdinalIgnoreCase.Equals(arg, "/?");
					doHelp |= StringComparer.OrdinalIgnoreCase.Equals(arg, "/help");
					doHelp |= StringComparer.OrdinalIgnoreCase.Equals(arg, "-?");
					doHelp |= StringComparer.OrdinalIgnoreCase.Equals(arg, "-help");

                    if(arg.StartsWith("--descriptor_set_out="))
                    {
                        tempFile = arg.Substring("--descriptor_set_out=".Length);
                        protoGenArgs.Add(tempFile);
                    }
                }

				if (doHelp)
				{
					Console.WriteLine();
					Console.WriteLine("PROTOC.exe: Use any of the following options that begin with '--':");
					Console.WriteLine();
					try { RunProtoc("--help"); }
					catch (Exception ex) { Console.Error.WriteLine(ex.Message); }
					Console.WriteLine();
					Console.WriteLine();
					Console.WriteLine("PRTOGEN.exe: The following options are used to specify defaults for code generation.");
					Console.WriteLine();
					Program.Main(new string[0]);
					return 0;
				}

				foreach (string arg in args)
				{
					if (arg.StartsWith("--"))
						protocArgs.Add(arg);
					else if (File.Exists(arg) && StringComparer.OrdinalIgnoreCase.Equals(".proto", Path.GetExtension(arg)))
					{
						if (tempFile == null)
						{
							deleteFile = true;
							tempFile = Path.GetTempFileName();
							protocArgs.Add(String.Format("--descriptor_set_out={0}", tempFile));
							protoGenArgs.Add(tempFile);
						}
						protocArgs.Add(arg);
					}
					else
						protoGenArgs.Add(arg);
				}

            	if (tempFile != null)
                {
                    result = RunProtoc(protocArgs.ToArray());
                    if (result != 0)
                        return result;
                }

                result = Program.Main(protoGenArgs.ToArray());
            }
            finally
            {
                if (deleteFile && tempFile != null && File.Exists(tempFile))
                    File.Delete(tempFile);
            }
            return result;
        }

        private static int RunProtoc(params string[] args)
        {
            const string protoc = "protoc.exe";
            string exePath = protoc;

            //why oh why is this not in System.IO.Path or Environment...
            List<string> searchPath = new List<string>();
            searchPath.Add(Environment.CurrentDirectory);
            searchPath.Add(AppDomain.CurrentDomain.BaseDirectory);
            searchPath.AddRange((Environment.GetEnvironmentVariable("PATH") ?? String.Empty).Split(Path.PathSeparator));

            foreach (string path in searchPath)
                if (File.Exists(exePath = Path.Combine(path, protoc)))
                    break;

            if (!File.Exists(exePath))
                throw new FileNotFoundException("Unable to locate " + protoc + " make sure it is in the PATH, cwd, or exe dir.");

            for (int i = 0; i < args.Length; i++)
                if (args[i].IndexOf(' ') > 0 && args[i][0] != '"')
                    args[i] = '"' + args[i] + '"';

            ProcessStartInfo psi = new ProcessStartInfo(exePath);
            psi.Arguments = String.Join(" ", args);
            psi.RedirectStandardError = true;
            psi.RedirectStandardInput = false;
            psi.RedirectStandardOutput = true;
            psi.ErrorDialog = false;
            psi.CreateNoWindow = true;
            psi.UseShellExecute = false;
            psi.WorkingDirectory = Environment.CurrentDirectory;

            Process process = Process.Start(psi);
            if (process == null) return 1;

            process.WaitForExit();

        	string tmp = process.StandardOutput.ReadToEnd();
			if(tmp.Trim().Length > 0) Console.Out.WriteLine(tmp);
			tmp = process.StandardError.ReadToEnd();
			if (tmp.Trim().Length > 0) Console.Error.WriteLine(tmp);
            return process.ExitCode;
        }
    }
}