Object.GetType()を呼び出さないとうまく動かないところが納得いかない。 → QA@ITに質問してみた。http://qa.atmarkit.co.jp/q/2834 → Monoの不具合だった。 → ushortからshortでの不具合は修正された。 → boolからsbyteでの不具合が見つかった。

.gitignore

/tmp.exe
/tmp2.exe

README-tmp2.md

自前ビルドしたC#コンパイラでコンパイルするとうまく動かないコードがある。

(tmp2.csを挿入)

うまく動かない場合はすべてにおいてFalseとなる。

value(-64) <     -1 => False
value(-64) <  -0x20 => False
value(-64) <  -0x80 => False

本来次のような結果になるはず。

value(-64) <     -1 => True
value(-64) <  -0x20 => True
value(-64) <  -0x80 => False

これは何が起きているのだろうか?

問題のないコンパイラ

csc.exe

Microsoft (R) Visual C# Compiler Version 4.0.30319.17929
for Microsoft (R) .NET Framework 4.5
Copyright (C) Microsoft Corporation. All rights reserved.

Mac OS X版3.0.6 (公式配布物)

Mono JIT compiler version 3.0.6 (master/20e40c4 Wed Feb 27 10:15:23 EST 2013)
Copyright (C) 2002-2012 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
        TLS:           normal
        SIGSEGV:       altstack
        Notification:  kqueue
        Architecture:  x86
        Disabled:      none
        Misc:          softdebug 
        LLVM:          yes(3.1svn-mono)
        GC:            Included Boehm (with typed GC)

ideon.com (mono-2.8)

See http://ideone.com/SU6Ma0

問題が起きるコンパイラ

FreeBSD ports lang/mono (Mono 3.0.3) on FreeBSD 9.1-STABLE

Mono JIT compiler version 3.0.3 (tarball Fri Apr 19 16:54:49 JST 2013)
Copyright (C) 2002-2012 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
        TLS:           __thread
        SIGSEGV:       altstack
        Notification:  kqueue
        Architecture:  amd64
        Disabled:      none
        Misc:          softdebug
        LLVM:          supported, not enabled.
        GC:            Included Boehm (with typed GC and Parallel Mark)

自前ビルド版3.0.6 on FreeBSD 9.1-STABLE

Mono JIT compiler version 3.0.6 (mono-3.0.6/20e40c4 2013年 4月19日 金曜日 20時21分40秒 JST)
Copyright (C) 2002-2012 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
        TLS:           __thread
        SIGSEGV:       normal
        Notification:  kqueue
        Architecture:  amd64
        Disabled:      none
        Misc:          softdebug
        LLVM:          supported, not enabled.
        GC:            Included Boehm (with typed GC and Parallel Mark)

自前ビルド版3.0.6 on Mac OS X 10.7.5

Mono JIT compiler version 3.0.6 (mono-3.0.6/20e40c4 2013年 4月19日 金曜日 20時57分05秒 JST)
Copyright (C) 2002-2012 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
        TLS:           normal
        SIGSEGV:       altstack
        Notification:  kqueue
        Architecture:  amd64
        Disabled:      none
        Misc:          softdebug 
        LLVM:          supported, not enabled.
        GC:            Included Boehm (with typed GC)

自前ビルド版3.0.10 on FreeBSD 9.1-STABLE

Mono JIT compiler version 3.0.10 (master/1c94cd3 2013年 4月19日 金曜日 19時24分22秒 JST)
Copyright (C) 2002-2012 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
        TLS:           __thread
        SIGSEGV:       normal
        Notification:  kqueue
        Architecture:  amd64
        Disabled:      none
        Misc:          softdebug
        LLVM:          supported, not enabled.
        GC:            Included Boehm (with typed GC and Parallel Mark)

README.md

Tested environments:

• Mono JIT compiler version 3.0.3 (tarball Thu Apr 11 19:43:51 JST 2013) from FreeBSD ports on FreeBSD 9.1-STABLE
• Mono JIT compiler version 3.0.6 (master/20e40c4 Wed Feb 27 10:15:23 EST 2013) from Official release on Mac OS X 10.7.5
• Mono JIT compiler version 3.0.10 (master/add2135 2013年 4月12日 金曜日 14時20分10秒 JST) from GitHub on FreeBSD 9.1-STABLE

See QA@IT/2834: http://qa.atmarkit.co.jp/q/2834

Tested online services:

• Mono 2.10 on LiveWorkSpace ... http://liveworkspace.org/code/yhxj$0
• Mono 2.8 on ideone.com ... http://ideone.com/1jU11w

build-mono.sh

#!/bin/sh
set -e -x
if [ $# == 0 ]; then
    echo "Usage: $0 BRANCH"
    exit 1
fi
branch_name=$1
case $branch_name in
    master)
	prefix=$HOME/local/stow/mono-git;
	;;
    mono-*)
	prefix=$HOME/local/stow/$1;
	;;
    *)
	echo "Invalid branch name: $1";
	exit 1
	;;
esac
jobs=`sysctl hw.ncpu | awk '{print $2}'`
case `uname` in
    FreeBSD)
	make=gmake
	;;
    *)
	make=make
	;;
esac
git reset --hard
if git branch | grep -e " $branch_name\$"; then
    git co $branch_name
else
    git co -b $branch_name $branch_name
fi
git reset --hard
git submodule init
git submodule update
case `uname` in
    FreeBSD)
        patch -p0 < /usr/ports/lang/mono/files/patch-mono_io-layer_sockets.c
	;;
    *)
        ;;
esac
NOCONFIGURE=1 ./autogen.sh
rm -rf _build_
mkdir _build_
cd _build_
../configure --prefix=$prefix --without-x --disable-nls
$make -j$jobs
rm -rf $prefix/$branch_name
$make -j$jobs install
#stow -d $HOME/local/stow -R $branch_name

build-tmp.sh

#!/bin/sh
set -e
#mcs tmp.cs
#mono tmp.exe
mcs tmp2.cs
mono tmp2.exe

tmp.cs

using System;
using System.Reflection;

namespace Tmp
{
  public class Packer
  {
    public Packer()
    {
    }

    public void PackUInt16(ushort value)
    {
    }

    public void PackInt16(short value)
    {
      //value.GetType();
      Console.WriteLine("value({0}) <  -0x80 => {1}", value, value < -0x80);
      Console.WriteLine("value({0}) <  -0x20 => {1}", value, value < -0x20);
      Console.WriteLine("value({0}) <   0x80 => {1}", value, value < 0x80);
      Console.WriteLine("value({0}) <  0x100 => {1}", value, value < 0x100);
    }

    public void PackObject<T>(T obj)
    {
      Type this_type = this.GetType();
      string obj_type_name = obj.GetType().ToString();
      string method_name = "Pack" + obj_type_name.Substring(obj_type_name.LastIndexOf(".") + 1);
      //Console.WriteLine(method_name);
      MethodInfo mi = this_type.GetMethod(method_name);
      mi.Invoke(this, new object[] { obj });
    }

    public static void Main()
    {
      Packer packer = new Packer();
      packer.PackObject((ushort)0);
      packer.PackObject((short)-1);
    }
  }
}

tmp2.cs

using System;
using System.Reflection;

namespace Tmp
{
  public class Packer
  {
    public Packer()
    {
    }

    public void PackBoolean(bool value)
    {
    }

    public void PackSByte(sbyte value)
    {
      //value.GetType();
      Console.WriteLine("value({0}) <     -1 => {1}", value, value <    -1);
      Console.WriteLine("value({0}) <  -0x20 => {1}", value, value < -0x20);
      Console.WriteLine("value({0}) <  -0x80 => {1}", value, value < -0x80);
    }

    public void PackObject<T>(T obj)
    {
      Type this_type = this.GetType();
      string obj_type_name = obj.GetType().ToString();
      string method_name = "Pack" + obj_type_name.Substring(obj_type_name.LastIndexOf(".") + 1);
      //Console.WriteLine(method_name);
      MethodInfo mi = this_type.GetMethod(method_name);
      mi.Invoke(this, new object[] { obj });
    }

    public static void Main()
    {
      Packer packer = new Packer();
      packer.PackObject(true);
      packer.PackObject((sbyte)-0x40);
    }
  }
}