"Attach to Process" as a post-build event

Question

I have an application that runs hosted under the "w3wp.exe" process.

While debugging, I often find myself following these steps:

1 - Make some change

2 - Build the project

3 - Attach to "w3wp.exe" using the "attach to process" dialog under the Tools menu.

4 - Perform some action in the application to make my code execute, so I can step through it in the debugger

I'd like to automate step 3 in the post-build script, so that the IDE automatically attaches to the process after the build is completed. Note that I already launch the application as a part of the post-build process, so I can count on the process existing at this point.

Does anyone know a way to automate the "attach to process" command? Something from the command line would be especially nice, but a macro would do, too.

I'm using Visual Studio 2008 under Windows 7, 64 bit.

Edit @InSane basically gave me the right answer, but it does not work because I need to debug managed code, rather than native code. It seems that vsjitdebugger defaults to Native code, and thus my breakpoint is not hit. From inside the IDE, I can specify "managed code" and the debugger attaches as expected. So is there any way to point vsjitdebugger to managed code?

Answer 1

I was finally able to solve this problem with an example I found elsewhere on the internet. I'm sharing it here since this was helpful to me.

1 - Create a new command line application with the below code (this example is in VB.NET).

Option Strict Off
Option Explicit Off
Imports System
'On my machine, these EnvDTE* assemblies were here:
'C:\Program Files (x86)\Common Files\microsoft shared\MSEnv\PublicAssemblies
Imports EnvDTE
Imports EnvDTE80
Imports EnvDTE90
Imports System.Diagnostics
Imports System.Threading

Module modMain
    Function AttachToProcess(ByVal processName As String, _
                             ByVal Timeout As Integer) As Boolean
        Dim proc As EnvDTE.Process
        Dim attached As Boolean
        Dim DTE2 As EnvDTE80.DTE2

        Try
            DTE2 = _
            System.Runtime.InteropServices.Marshal.GetActiveObject("VisualStudio.DTE.9.0")

            For Each proc In DTE2.Debugger.LocalProcesses
                If (Right(proc.Name, Len(processName)).ToUpper = processName.ToUpper) Then
                    proc.Attach()
                    System.Threading.Thread.Sleep(Timeout)
                    attached = True
                End If
            Next
        Catch Ex As Exception
            Console.Write("Unable to Attach to Debugger : " & Ex.Message)
        End Try

        Return attached
    End Function

    Sub Main()
        'to call w/ Command Line arguments follow this syntax
        'AttachProcess <<ProcessName>> <<TimeOut>>
        'AttachProcess app.exe 2000
        Dim AppName As String = "w3wp.exe"
        Dim TimeOut As Integer = 20000 '20 Seconds
        Try
            If Environment.GetCommandLineArgs().Length > 1 Then
                AppName = Environment.GetCommandLineArgs(1)
            End If

            If Environment.GetCommandLineArgs().Length > 2 Then
                If IsNumeric(Environment.GetCommandLineArgs(2)) Then
                    TimeOut = Environment.GetCommandLineArgs(2)
                End If
            End If
            Environment.GetCommandLineArgs()
            AttachToProcess(AppName, TimeOut)
            Console.WriteLine("Attached!!")

        Catch Ex As Exception
            Console.Write("Unable to Attach to Debugger : " & Ex.Message)
        End Try
    End Sub
End Module

2 - Open the solution you want to debug in Visual Studio

3 - At the end of your "post-build" events, enter a call to this new utility, as in:

c:\AutoAttach.exe w3wp.exe 20000

4 - Build your application