BorisJ's Blog : VC++ IDE Tips & Tricks

Debugging Trick

borisj — Tue, 22 Aug 2006 19:38:56 GMT

My colleague Kang Su (that's his first name) came by my office yesterday to borrow a book. You might think a story that starts like this couldn't possibly lead to anything interesting. This tale is compelling though so hang tight. So the book in question was Debugging Applications for Microsoft .NET and Microsoft Windows (what a mouthful!). It's supposedly a classic and Kang Su could not find his copy. As we were chatting, he decided to bring up the issue for which he wanted to borrow the book in the first place. Kang Su, being the most technical PM to grace the halls of Visual C++, wanted to debug Phoenix (the next generation compiler) using Visual Studio. The problem lies in the fact that he does not have a solution and the executable relies on a bunch of environment variables. He asked me for a way to launch the app, in the debugger, with the environment set, all in one fell swoop. Instead of letting him leaf through the 800+ pages of the tome he was taking, I decided to take a look at the command-line switches for devenv.exe. Lo and behold, the answer was simple.

> set ENV_VARIABLE=value

> devenv /useenv /debugexe myapp.exe [ <myapp arguments> ]

That's all folks!

Useful Code: Swap .h/.cpp

borisj — Mon, 25 Jul 2005 23:18:00 GMT

Over the past few weeks, for a number of reasons I have been working on a number of macros to extend the functionality of Visual C++. The first reason is that I have been giving preparing demos for various talks, such as Gamefest (which I mentioned earlier) as well as PDC. In these talks, we stress the many ways users can customize the IDE to suit their needs and extending it with macros is a key part of that. The second, more important reason, is that a number of customers have asked for features that we simply cannot add to the product at this point in the release cycle. When the developers on my team heard I was doing this, they even went so far as to say I was doing "their job". Needless to say I was quite flattered :) What's more, they started mentioning that they had a bunch of their own, which they'd been keeping to themselves this whole time!

Although this post is meant to discuss a specific macro (first among a few I'll be posting), I want to talk a bit about Visual Studio's extensibility model. If you've already written add-ins or macros then this may be old news, and I promise to keep it brief.

Writing macros for Visual Studio is quite simple (could you guess I was going to say that?). You can access the macros editor, which is simply a sub-session of VS, from the Tools menu, under the macros entry, or with the Alt+F11 shortcut. If it's the first time you do this, you should see a project called MyMacros with an empty module called Module1, which is a great starting point to write a macro. At this point, you will have inevitably noticed that you have entered the wonderful world of VB development where it seems as though everything is taken care of for you… The two core APIs for C++ oriented macro development are DTE, which provides access to the IDE functionality, and the VCCodeModel, which is the gateway to working with the code inside the IDE. As I unveil more macros, I'll expound more on these interfaces.

Today's macro is a feature request I've often received from customers: "Give me a shortcut to swap between a .h and respective .cpp file". Ask and (sometimes) ye shall receive so here is the code in all its simplistic glory. The comments should speak for themselves…

Sub SwapHeaderImpl()

' get the currently active document from the IDE

Dim doc As EnvDTE.Document = DTE.ActiveDocument

' get the name of the document (lower-case)

Dim docname As String = doc.Name.ToLower

' get the project that contains this document

Dim project As Project = doc.ProjectItem.ContainingProject

' verify that we are working with a C++ document

If doc.Language = EnvDTE.Constants.dsCPP Then

' switch file name string between *.h <-> *.cpp

If docname.EndsWith(".h") Then

docname = docname.Replace(".h", ".cpp")

ElseIf docname.EndsWith(".cpp") Then

docname = docname.Replace(".cpp", ".h")

End If

' find file in current project and open it (can you spot the flaw in this section?)

Dim item As ProjectItem

For Each item In project.ProjectItems

' compare and open

If docname = item.Name.ToLower() Then

DTE.ItemOperations.OpenFile(item.FileNames(0), Constants.vsViewKindCode)

Exit Sub

End If

' if file was not in project, search include paths

Dim vcproj As VCProject = project.Object

Dim config As VCConfiguration = vcproj.Configurations(1)

Dim compiler As VCCLCompilerTool = config.Tools("VCCLCompilerTool")

Dim path As String

For Each path In compiler.FullIncludePath.Split(";")

If My.Computer.FileSystem.FileExists(path + "\" + docname) Then

DTE.ItemOperations.OpenFile(path + "\" + docname, Constants.vsViewKindCode)

End If

End Sub

You probably noticed that I point a flaw in the code above. Indeed, the code above won't be useful as it does not traverse the entire list of files contained in a project. The problem lies in the fact that some items within a project are both an item and a container of more items (i.e. folders/filters). These items can be accessed both as a ProjectItem object and as a ProjectItems object. Furthermore, items can be deeply nested, so in order to reach every file in a project, we need a recursive function such as the following.

Sub OpenInProjectItems(ByVal name As String, ByVal projItems As EnvDTE.ProjectItems)

Dim projItem As EnvDTE.ProjectItem

' Find all ProjectItem objects in the given collection

For Each projItem In projItems

If name = projItem.Name.ToLower() Then

DTE.ItemOperations.OpenFile(projItem.FileNames(0), Constants.vsViewKindCode)

Exit Sub

End If

' recurse to get deeply nested items

OpenInProjectItems(name, projItem.ProjectItems)

End Sub

We can now rewrite the original macro using this helper function.

Sub SwapHeaderImpl()

' get the currently active document from the IDE

Dim doc As EnvDTE.Document = DTE.ActiveDocument

' get the name of the document (lower-case)

Dim docname As String = doc.Name.ToLower

' get the project that contains this document

Dim project As Project = doc.ProjectItem.ContainingProject

' verify that we are working with a C++ document

If doc.Language = EnvDTE.Constants.dsCPP Then

' switch file name string between *.h <-> *.cpp

If docname.EndsWith(".h")

docname = docname.Replace(".h", ".cpp")

ElseIf docname.EndsWith(".cpp") Then

docname = docname.Replace(".cpp", ".h")

End If

' find file in current project and open it

OpenInProjectItems(docname, project.ProjectItems)

' if file was not in project, search include paths

Dim vcproj As VCProject = project.Object

Dim config As VCConfiguration = vcproj.Configurations(1)

Dim compiler As VCCLCompilerTool = config.Tools("VCCLCompilerTool")

Dim path As String

For Each path In compiler.FullIncludePath.Split(";")

If My.Computer.FileSystem.FileExists(path + "\" + docname) Then

DTE.ItemOperations.OpenFile(path + "\" + docname, Constants.vsViewKindCode)

End If

End Sub

I should also discuss the lower part of the code where the macro attemps to reach files outside of the project. Often, C++ developers may be implementing headers that are not added to the project but that are in the project's include path. In order to support this common scenario, the macro digs into the VC automation engine, as evidenced by the use of VCProject, VCConfiguration and VCCLCompilerTool. Navigating these APIs is a little more difficult but there is a lot of functionality buried in them. In this case, I load the first configuration (ideally I should retrieve the active configuration) for the project and then load the object containing all the properties of the compiler build event. Within this object I find the FullIncludePath property, which I can split to obtain all possible locations accessible from this project.

Voila!

GameFest I

borisj — Thu, 30 Jun 2005 08:13:00 GMT

I've spent the past two days at GameFest, presenting some tips and tricks for the Visual C++ IDE and talking to game developers. The conference was based in Bellevue (so no fancy traveling this time) and, as I mentioned before, it is geared mainly towards Xbox developers. It's really quite nice for us, as members of the C++ team, to see so many consumers (or is that producers?) of good ol' native code. It sure seems like game programming and system programming are the last bastions of *real* C++ usage. I found that all the things they wanted to see in the IDE that aren't yet present were features I would also personally want to see. In other words, for all the attendees that asked me for features, if you are reading this, look out for some of those improvements in the future.

After that preamble, let me expand on my previous note relating to Epic. Indeed, we were blessed with the presence of none other than Tim Sweeney, the head of Epic Games, who has been building amazing game engines for 14 years now. If the name doesn't ring a bell than perhaps their flagship, the Unreal Engine, does (if not, you fail the gamer test!). The talk he gave on Tuesday evening was highly attended, as everyone was excited to see what he would demo. In fact, the majority of the presentation was successive demos. He showed off a *real* demo (no pre-rendered crap) of their upcoming game called Gears of War and all I can say is wow. Let me clarify, although I don't believe the graphics of the Xbox 360 and PS3 era will be as mind-blowing as some may insinuate, they will clearly be awesome. On that note, AnandTech has a decent article describing the overall architectures of both systems (although you'll want to hit Ars Technica for the real in-depth stuff).

On Wednesday morning (today for me), I gave my talk about unlocking the hidden power of the Visual C++ IDE! Okay, so it didn't sound that fancy, but I presented a bunch of lesser known tips and tricks, some of which really resonate with game developers (e.g. how to improve build time!). The room was filled to the brim even though it was the first talk of the day and the feedback I got was awesome. It was obvious they were dedicated users who really want Visual C++ to be as great as possible. Luckily, I feel the same way :) Watch in the next couple of days as I put up some of the tips I presented, some of the ones I omitted and some of the stuff I created just to show off...

VS 2005 vs. Firefox

borisj — Sun, 26 Jun 2005 03:27:00 GMT

Thanks to Don for pointing this one out, I bet Sara will blog about this in no time too... Since Visual Studio 2005 uses tabs for managing all the different files one would edit, one can naturally apply to browsing the web. Personally, I don't see this as a new way to browse the web, but the focus on making the tabbed interface pervasive and intuitive in VS 2005 is really awesome. As an extra, the middle-click really is well supported, including one of my favorites, which is the ability to close tabs that way.

Where is my Source Browser?

borisj — Fri, 03 Jun 2005 00:21:00 GMT

If you're an experienced Visual C++ 6.0 user, chances are you've become quite attached to the Source Browser tool. This tool provided rich browsing functionality for any project that generated a .bsc file. It was accessible from the Alt+F12 shortcut, and users could obtain information for an identifier. The choices were things like "Definitions and References", "Base Classes", "Derived Classes" and "Call/Callers Graph". Well needless to say, if you have used Whidbey, you know that we have made sure to provide all this functionality. In addition, we have made it much simpler to use and more ubiquitous. In other words, much of the functionality is available through direct means such as the "Class View" window, which shows base and derived classes. In addition to spreading the functionality across the IDE, we have a browsing tool called the Object Browser (so don't go looking for the name Source Browser). This feature was sorely lacking from 2002 and 2003 and we took special care to re-create it and improve it. For example, creating the bsc file was always a bit of an issue, as it could add 10-15% to a project's build time, and more importantly, it meant that the information visible in the source browser was only as fresh as the last compilation. With Visual C++ 2005, we have eliminated the need for that file, instead the Intelllisense engine adds that information to its store so that it is always available and always live. On the other hand, you can still generate the file and it can opened in the Object Browser in order to get this information without having a project for it. I recently came across a customer who asked why he could browse the entire .NET framework in the Object Browser but could not do the same for MFC. I was happy to reply that is very easy to do this! All one needs to do is add the mfc.bsc file into the Custom Component Set of the Object Browser and voila!

Well, that's enough of a spiel (I have to figure out how to add pictures to this post as it would definitely help :)

Finally, I urge you to send me/us your feedback on this area because we really want to make sure it meets the needs of every single VC++ 6.0 user. And by the way, the Call Graph (a.k.a. Call Browser) functionality is *only* available in C++. Take that C#!

New for VC++ 2005: CTRL+J

borisj — Tue, 19 Apr 2005 22:22:00 GMT

Have you ever been coding inside a class/struct and you wanted to know just what members were available to you in that scope? Have you ever found yourself typing this-> just to see those members? Well, there's a new shortcut in VC 2005 that allows you to do just that! CTRL+J will show you a dropdown containing only elements in the current scope, excluding all the outer library methods etc... Of course, you can always assign this command to a different shortcut using the keyboard mapping tool (under Tools\Options\Environment\Keyboard). The command is listed as Edit.ListMembers

Find symbols VC6-style using CTRL+D

borisj — Tue, 12 Apr 2005 03:21:00 GMT

Many developers complain about the fact that the traditional search box that pops up when using CTRL+F stays open after finding the first instance of the symbol in question. This forces the user to perform an extra keystroke (namely Escape) and just does not fit in the expected experience of many. Thankfully there is an alternative that provides an experience closer to VC6: the quick find combo box. Pressing CTRL+D jumps the cursor to the quick find box (top-right) where a user can enter any string, press enter and voila: the string is highlighted and the cursor is exactly where you would expect.

The quick find box is actually very powerful and I am sure I will bring it up again.