gistfile1.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using Mono.Cecil;
using Mono.Cecil.Cil;

namespace ConsoleApplication9
{
    class Program
    {
        static void Main(string[] args)
        {
            var asm = AssemblyDefinition.ReadAssembly("ConsoleApplication9.exe");
            var mod = asm.MainModule;
            var types = mod.Types;
            var methods = types.Where(_ => _.Name == typeof(Target).Name).SelectMany(_ => _.Methods).Where(_ => _.IsStatic);
            var bodies = methods.Select(_ => _.Body);

            // 
            foreach (var body in bodies.Where(HasBadOperationForIDisposable))
                Console.WriteLine(body.Method.ToString());
        }

        static bool HasBadOperationForIDisposable(MethodBody body)
        {
            if (!body.HasExceptionHandlers)
                return true;

            var finallyClauses = body.ExceptionHandlers.Where(_ => _.HandlerType == ExceptionHandlerType.Finally);
            if (!finallyClauses.Any())
                return true;

            foreach (var inst in finallyClauses.SelectMany(_ => _.EnumerateInstructions()))
            {
                var memberRef = inst.Operand as MemberReference;
                if (Regex.IsMatch(memberRef + "", @"::Dispose\(\)"))
                    return false;
            }

            return true;
        }

    }

    static class ExceptionHandlerMixin
    {
        public static IEnumerable<Instruction> EnumerateInstructions(this ExceptionHandler clause)
        {
            for (Instruction current = clause.HandlerStart, last = clause.HandlerEnd;
                 current.Offset <= last.Offset && current.Next != null;
                 current = current.Next)
            {
                yield return current;
            }
        }
    }

    public class Target
    {
        public static void GoodDispose1()
        {
            using (var fs = new FileStream("", FileMode.Open)) { }
        }

        public static void GoodDispose2()
        {
            try
            {
                using (var fs = new FileStream("", FileMode.Open)) { }
            }
            catch
            {
                throw;
            }
        }

        public static void GoodDispose3()
        {
            try
            {
                using (var fs = new FileStream("", FileMode.Open)) { }
            }
            catch
            {
                throw;
            }
            finally
            {
                Console.WriteLine("終了！");
            }
        }

        public static void GoodDispose4()
        {
            try
            {
                var fs = default(FileStream);
                try
                {
                    fs = new FileStream("", FileMode.Open);
                }
                finally
                {
                    if (fs != null)
                        fs.Dispose();
                }
            }
            catch
            {
                throw;
            }
            finally
            {
                Console.WriteLine("終了！");
            }
        }

        public static void BadDispose1()
        {
            var fs = new FileStream("", FileMode.Open);
        }

        public static void BadDispose2()
        {
            try
            {
                var fs = new FileStream("", FileMode.Open);
            }
            catch
            {
                throw;
            }
        }

        public static void BadDispose3()
        {
            try
            {
                var fs = new FileStream("", FileMode.Open);
            }
            catch
            {
                throw;
            }
            finally
            {
                Console.WriteLine("終了！");
            }
        }

        public static void BadDispose4()
        {
            try
            {
                try
                {
                    var fs = new FileStream("", FileMode.Open);
                    fs.Dispose();
                }
                finally
                {

                }
            }
            catch
            {
                throw;
            }
            finally
            {
                Console.WriteLine("終了！");
            }
        }
    }
}