Why should you delete the 'obj' folder on every build? - visual-studio

I'm new on a project and the building is quite slow.
Now I see as a postbuild event the next action for a lot of projects:
<PostBuildEvent>rd "$(ProjectDir)obj" /S /Q</PostBuildEvent>
I've read that the obj folder keeps track of the builds so incremental builds can be faster, so I thought maybe this has something to do with it.
However, nobody in my team know why this is done, the removal of this folder, so I'm a bit hesitant to just remove the build action.
What can be a reason to perform this action?

A couple of things come to mind (all rather questionable by themselves):
Custom build steps in the same, or - God forbid - other project that requires it (for the next build to succeed).
A (misguided) attempt to preserve disk space (since all "precious" is in "bin" after the build you technically don't need "obj").
A (misguided) attempt to implement "clean, clobber, etc."-semantics
One needs more information about the complete build system, other projects, etc. you have in place to find out more or better reasons - if at all ;-)

The single possible reason to perform such kind of action is lack of knowledge about power of MSBuild utility.
I believe that target requirement (if it exist) could be achived another way, which will not omit the incremental build feature.
Try to find the author of that string in VCS you are using, and if author is unavailable or could not answer the question, warn your colleagues and remove it and see what happens.

There is a bug in Visual Studio where if you move the obj directory with the IntermediateOutputPath defined in the project file then the compiler still creates an empty obj directory any way. I do both myself, but with VS2010. If VS2015 has this fixed you may be able to remove it.

Related

Managing VS2010 References With CopyLocal=False

I'm trying to improve our build process, and to that end I've been looking at turning off copy local and having the whole solution build to a common \bin directory.
What however, is best practise for getting the no longer copied references into the bin directory? I don't want to do this in one of the actual implementation projects as many of them use the same referenced components, and it will mean a proliferation of post build steps.
I know I could create a custom msbuild file but then that would need to be run manually outside of visual studio (I think)? which seems like friction. Is there a way I can create an msbuild project for example, and then have that as part of my solution.
Or is it best just to manage this outside my solution build and have a copy_references.bat file which the dev has to run once to setup their environment getting them into the /bin/debug and /bin/release directories? This seems a bit fragile, but better than checking /bin and the files into svn directly.
One idea I've had is to create an empty c# component project and add the references to it, with copy local turned on. If this was then made a dependency of all other projects it would manage the copying.
Next question is how to manage this with nuget references? My preference is to not check the references into svn, but tell nuget to grab them. So this would also need to be a build step, but again at the solution level.
Additional Info
For a bit more background on why I am evaluating this approach, have a look here:
http://www.ndepend.com/Res%5CNDependWhiteBook_Assembly.pdf
The goal is to massively speed up compilation time by stopping all these redundant copies. Also side benefits if it works might be not having to manually work around the times dependency evaluation doesn't work. Causing one to have to pull referenced assemblies' dependencies into your top level project to ensure they end up in the bin folder.
I suppose in some ways the desire to turn off copy local is an artifact of the inefficiency of the ms build process at both tracing dependencies and evaluating the need to copy things.
You can override the $(OutDir) property globally and keep CopyLocal enabled. Since every project is copying to the same $(OutDir), you won't end up with too much duplication. This is pretty straight forward.
Much more involved, you can also create a shared import file that wires into the standard build and performs a custom post-build deployment. For example,
<Target Name="Deploy"
DependsOnTargets="Deploy)"
AfterTargets="Build">
... copy all output files ...
e.g. use wildcards $(OutDir)\*.dll
e.g. $(OutDir)\$(TargetName)$(TargetExt)
e.g. copy referenced assemblies and copy, see below
</Target>
To get the references, you can call the ResovleAssemblyReferences target and use Returns, or create your own target to get a specific collection as shown in the answer here,
Return the ReferenceCopyLocalPaths from <MSBuild> task
It can be rather involved, but easily configured if you can declare your own "rules" in an item array with metadata.

How to setup the target output path of a given resource file in Visual Studio

In the main project of my VS Solution I have a Resources folder with some required external tools. When building and publishing the solution, I get a .\Resources* with all required files there.
So far so good.
However I have to move some files to the parent directory.
My first attempt was do so with the Post Build Events. It works and does move them the correct folder.
Nevertheless in the publish output they still appear in the Resources folder and I need them in the parent one :/
Is there any way to setup the target output path for resources in Visual Studio?
After some research and experimental, I solved my problem.
Still, here's what I learned in the process.
The first attempt was adding the file to the project root and mark it as a resource. After publishing it worked. But having those files in the project root its lame.
Since I needed some *.exe files compiled in another VS solution, added them as a project reference. Gave it a try and it passed the "Publish" test. But still.. not the best way to do it.
After that, with some scripting and a post-build event, I copied the required files to the correct folder. Works.. but after publishing, they don't appear in the package.
However, there is still a possibility with the Mage tool:
http://msdn.microsoft.com/en-us/library/acz3y3te.aspx
This lead to some promissing experiments, however they ended up helping me realize how limited the MS ClickOnce is, so I decided to try other tools.
Here's a good start to follow:
What alternatives are there to ClickOnce?
I had a similar situation once. I found it became more trouble than it was worth to customize output paths and such in Visual Studio, to the extent that I wanted.
I ended up letting Visual Studio do its own thing with regards to file/project structure, and wrote a post-build script to copy everything that was needed into a final, 'publish-ready' directory.
I then set the execution target in Visual Studio to the new location, so I could run/debug as normal, but with the new folder that was organized how I needed it. Careful, I think this is a user project setting; so other developers will need to do this on their machines too, if they so desire.
I do recall changing some output paths and such to make the post-build script more simple. But changing things like that can lead to annoyances when you add new projects to the solution; you might need to configure them to match. It's all a trade-off :)
Two ideas:
Maybe you could move your resources into another project - a project just for resources - and then set their Build Action to Content and Copy To Output to true. Then reference this new project and build the solution. (This may not work as you want, just an idea).
Why not make your resources embedded resources instead. Keep them all within the Resources\ directory and access them programatically?

Should a .sln be committed to source control?

Is it a best practice to commit a .sln file to source control? When is it appropriate or inappropriate to do so?
Update
There were several good points made in the answers. Thanks for the responses!
I think it's clear from the other answers that solution files are useful and should be committed, even if they're not used for official builds. They're handy to have for anyone using Visual Studio features like Go To Definition/Declaration.
By default, they don't contain absolute paths or any other machine-specific artifacts. (Unfortunately, some add-in tools don't properly maintain this property, for instance, AMD CodeAnalyst.) If you're careful to use relative paths in your project files (both C++ and C#), they'll be machine-independent too.
Probably the more useful question is: what files should you exclude? Here's the content of my .gitignore file for my VS 2008 projects:
*.suo
*.user
*.ncb
Debug/
Release/
CodeAnalyst/
(The last entry is just for the AMD CodeAnalyst profiler.)
For VS 2010, you should also exclude the following:
ipch/
*.sdf
*.opensdf
Yes -- I think it's always appropriate. User specific settings are in other files.
Yes you should do this. A solution file contains only information about the overall structure of your solution. The information is global to the solution and is likely common to all developers in your project.
It doesn't contain any user specific settings.
You should definitely have it. Beside the reasons other people mentioned, it's needed to make one step build of the whole projects possible.
I generally agree that solution files should be checked in, however, at the company I work for we have done something different. We have a fairly large repository and developers work on different parts of the system from time to time. To support the way we work we would either have one big solution file or several smaller. Both of these have a few shortcomings and require manual work on the developers part. To avoid this, we have made a plug-in that handles all that.
The plug-in let each developer check out a subset of the source tree to work on simply by selecting the relevant projects from the repository. The plugin then generates a solution file and modifies project files on the fly for the given solution. It also handles references. In other words, all the developer has to do is to select the appropriate projects and then the necessary files are generated/modified. This also allows us to customize various other settings to ensure company standards.
Additionally we use the plug-in to support various check-in policies, which generally prevents users from submitting faulty/non-compliant code to the repository.
Yes, things you should commit are:
solution (*.sln),
project files,
all source files,
app config files
build scripts
Things you should not commit are:
solution user options (.suo) files,
build generated files (e.g. using a build script) [Edit:] - only if all necessary build scripts and tools are available under version control (to ensure builds are authentic in cvs history)
Regarding other automatically generated files, there is a separate thread.
Yes, it should be part of the source control.
When ever you add/remove projects from your application, .sln would get updated and it would be good to have it under source control. It would allow you to pull out your application code 2 versions back and directly do a build (if at all required).
Yes, you always want to include the .sln file, it includes the links to all the projects that are in the solution.
Under most circumstances, it's a good idea to commit .sln files to source control.
If your .sln files are generated by another tool (such as CMake) then it's probably inappropriate to put them into source control.
We do because it keeps everything in sync. All the necessary projects are located together, and no one has to worry about missing one. Our build server (Ant Hill Pro) also uses the sln to figure which projects to build for a release.
We usually put all of our solutions files in a solutions directory. This way we separate the solution from the code a little bit, and it's easier to pick out the project I need to work on.
The only case where you would even considder not storing it in source control would be if you had a large solution with many projects which was in source control, and you wanted to create a small solution with some of the projects from the main solution for some private transient requirement.
Yes - Everything used to generate your product should be in source control.
We keep or solution files in TFS Version Control. But since or main solution is really large, most developers have a personal solution containing only what they need. The main solution file is mostly used by the build server.
.slns are the only thing we haven't had problems with in tfs!

Finding errors / warnings in Visual Studio

I have experienced an annoying issue with Visual Studio 2005... sometimes when I rebuild, and even if I do a Rebuild Solution, it will come back with no errors or warnings, but then when I later edit another code file, even without changing it, and rebuild, it will find an error or warning in that other file. Clearly, the earlier Rebuild Solution did not recompile that file! How can I force VS to completely recompile every file?
I've seen this happen before when you have multiple projects in your solution and the references get mixed up.
Say you have four projects in your solution, Common, Business, Data, and UI. Assume that Common is referenced by the other three projects.
What we want is for Common to be a "project reference" from the other three projects - they'll then pick up their copy from the build output directory of Common.
But, sometimes, one of the projects will get it's reference mixed up. Say, in this case, that UI starts referencing the copy of Common in the build output directory of Data. Now, any change that compiles "UI" without also compiling "Data" will result in two, possibly incompatible, versions of "Common" being a dependency of UI.
Another scenario is where the reference is to a binary, such as from a "lib" directory. Then, one of the projects ends up referring to a build output location instead of lib.
I don't know what causes this - but I see it all the time, unfortunately.
The fix is to go through the references of each project and find the one (or more) that point to the wrong place.
It might help to clean the solution prior to rebuilding -- right click on the solution in the Solution Explorer and choose "clean solution" -- this deletes temporary files and is supposed to clear out the bin and obj folders, so everything is rebuilt.
I'm with Guy Starbuck here, but would add that Rebuild Solution is supposed to do a Clean Solution followed by Build Solution, which should, then, have solved your issue to begin with. But VS 2005 can be terrible in this regard. Sometimes it just starts working after several rebuilds. If upgrading to 2008 isn't an option, consider manually clearing the bin folder.
Is this related to the Configuration Manager? There you can select which projects in your solution build. Not sure if this helps.
Depending on the types of warnings it is not possible if I recall correctly.
For example, warning messages for XHTML compliance are ONLY displayed when the file is open. You might check the tolerance settings inside VS to see if you can change it.
This sounds strange - Rebuild should build everything regardless of changes and Build should only build things that have changed.
The behaviour you've described should only happen if you have modified something that is referenced by the unchanged file so that it is now incorrect.

Structuring projects & dependencies of large winforms applications in C#

UPDATE:
This is one of my most-visited questions, and yet I still haven't really found a satisfactory solution for my project. One idea I read in an answer to another question is to create a tool which can build solutions 'on the fly' for projects that you pick from a list. I have yet to try that though.
How do you structure a very large application?
Multiple smallish projects/assemblies in one big solution?
A few big projects?
One solution per project?
And how do you manage dependencies in the case where you don't have one solution.
Note: I'm looking for advice based on experience, not answers you found on Google (I can do that myself).
I'm currently working on an application which has upward of 80 dlls, each in its own solution. Managing the dependencies is almost a full time job. There is a custom in-house 'source control' with added functionality for copying dependency dlls all over the place. Seems like a sub-optimum solution to me, but is there a better way? Working on a solution with 80 projects would be pretty rough in practice, I fear.
(Context: winforms, not web)
EDIT: (If you think this is a different question, leave me a comment)
It seems to me that there are interdependencies between:
Project/Solution structure for an application
Folder/File structure
Branch structure for source control (if you use branching)
But I have great difficulty separating these out to consider them individually, if that is even possible.
I have asked another related question here.
Source Control
We have 20 or 30 projects being built into 4 or 5 discrete solutions. We are using Subversion for SCM.
1) We have one tree in SVN containing all the projects organised logically by namespace and project name. There is a .sln at the root that will build them all, but that is not a requirement.
2) For each actual solution we have a new trunks folder in SVN with SVN:External references to all the required projects so that they get updated from their locations under the main tree.
3) In each solution is the .sln file plus a few other required files, plus any code that is unique to that solution and not shared across solutions.
Having many smaller projects is a bit of a pain at times (for example the TortoiseSVN update messages get messy with all those external links) but does have the huge advantage that dependancies are not allowed to be circular, so our UI projects depend on the BO projects but the BO projects cannot reference the UI (and nor should they!).
Architecture
We have completely switched over to using MS SCSF and CAB enterprise pattern to manage the way our various projects combine and interact in a Win Forms interface. I am unsure if you have the same problems (multiple modules need to share space in a common forms environment) but if you do then this may well bring some sanity and convention to how you architect and assemble your solutions.
I mention that because SCSF tends to merge BO and UI type functions into the same module, whereas previously we maintained a strict 3 level policy:
FW - Framework code. Code whose function relates to software concerns.
BO - Business Objects. Code whose function relates to problem domain concerns.
UI - Code which relates to the UI.
In that scenario dependancies are strictly UI -> BO -> FW
We have found that we can maintain that structure even while using SCSF generated modules so all is good in the world :-)
To manage dependencies, whatever the number of assemblies/namespaces/projects you have, you can have a glance at the tool NDepend.
Personnaly, I foster few large projects, within one or several solutions if needed. I wrote about my motivations to do so here: Benefit from the C# and VB.NET compilers perf
I think it's quite important that you have a solution that contains all your 80 projects, even if most developers use other solutions most of the time. In my experience, I tend to work with one large solution, but to avoid the pain of rebuilding all the projects each time I hit F5, I go to Solution Explorer, right-click on the projects I'm not interested in right now, and do "Unload Project". That way, the project stays in the solution but it doesn't cost me anything.
Having said that, 80 is a large number. Depending on how well those 80 break down into dicrete subsystems, I might also create other solution files that each contain a meaningful subset. That would save me the effort of lots of right-click/Unload operations. Nevertheless, the fact that you'd have one big solution means there's always a definitive view of their inter-dependencies.
In all the source control systems that I've worked with, their VS integration chooses to put the .sln file in source control, and many don't work properly unless that .sln file is in source control. I find that intriguing, since the .sln file used to be considered a personal thing, rather than a project-wide thing. I think the only kind of .sln file that definitely merits source control is the "one-big-solution" that contains all projects. You can use it for automated builds, for example. As I said, individuals might create their own solutions for convenience, and I'm not against those going into source control, but they're more meaningful to individuals than to the project.
I think the best solution is to break it in to smaller solutions. At the company I currently work for, we have the same problem; 80 projects++ in on solution. What we have done, is to split into several smaller solutions with projects belonging together. Dependent dll's from other projects are built and linked in to the project and checked in to the source control system together with the project. It uses more disk space, but disk is cheap. Doing it this way, we can stay with version 1 of a project until upgrading to version 1.5 is absolutely necessary. You still have the job with adding dll's when deciding to upgrade to a other version of the dll though. There is a project on google code called TreeFrog that shows how to structure the solution and development tree. It doesn't contain mush documentation yet, but I guess you can get a idea of how to do it by looking at the structure.
A method that i've seen work well is having one big solution which contains all the projects, for allowing a project wide build to be tested (No one really used this to build on though as it was too big.), and then having smaller projects for developers to use which had various related projects grouped together.
These did have depencies on other projects but, unless the interfaces changed, or they needed to update the version of the dll they were using, they could continue to use the smaller projects without worrying about everything else.
Thus they could check-in projects while they were working on them, and then pin them (after changing the version number), when other users should start using them.
Finally once or twice a week or even more frequently the entire solution was rebuild using pinned code only, thus checking if the integration was working correctly, and giving testers a good build to test against.
We often found that huge sections of code didn't change frequently, so it was pointless loading it all the time. (When you're working on the smaller projects.)
Another advantage of using this approach is in certain cases we had pieces of functionality which took months to complete, by using the above approach meant this could continue without interrupting other streams of work.
I guess one key criteria for this is not having lots of cross dependencies all over your solutions, if you do, this approach might not be appropriate, if however the dependencies are more limited, then this might be the way to go.
For a couple of systems I've worked on we had different solutions for different components. Each solution had a common Output folder (with Debug and Release sub-folders)
We used project references within a solution and file references between them. Each project used Reference Paths to locate the assemblies from other solutions. We had to manually edit the .csproj.user files to add a $(Configuration) msbuild variable to the reference paths as VS insists on validating the path.
For builds outside of VS I've written msbuild scripts that recursively identify project dependencies, fetch them from subversion and build them.
I gave up on project references (although your macros sound wonderful) for the following reasons:
It wasn't easy to switch between different solutions where sometimes dependency projects existed and sometimes didn't.
Needed to be able to open the project by itself and build it, and deploy it independently from other projects. If built with project references, this sometimes caused issues with deployment, because a project reference caused it to look for a specific version or higher, or something like that. It limited the mix and match ability to swap in and out different versions of dependencies.
Also, I had projects pointing to different .NET Framework versions, and so a true project reference wasn't always happening anyways.
(FYI, everything I have done is for VB.NET, so not sure if any subtle difference in behavior for C#)
So, I:
I build against any project that is open in the solution, and those that aren't, from a global folder, like C:\GlobalAssemblies
My continuous integration server keeps this up to date on a network share, and I have a batch file to sync anything new to my local folder.
I have another local folder like C:\GlobalAssembliesDebug where each project has a post build step that copies its bin folder's contents to this debug folder, only when in DEBUG mode.
Each project has these two global folders added to their reference paths. (First the C:\GlobalAssembliesDebug, and then C:\GlobalAssemblies). I have to manually add this reference paths to the .vbproj files, because Visual Studio's UI addes them to the .vbprojuser file instead.
I have a pre-build step that, if in RELEASE mode, deletes the contents from C:\GlobalAssembliesDebug.
In any project that is the host project, if there are non dlls that I need to copy (text files outputted to other project's bin folders that I need), then I put a prebuild step on that project to copy them into the host project.
I have to manually specify the project dependencies in the solution properties, to get them to build in the correct order.
So, what this does is:
Allows me to use projects in any solution without messing around with project references.
Visual Studio still lets me step into dependency projects that are open in the solution.
In DEBUG mode, it builds against open loaded projects. So, first it looks to the C:\GlobalAssembliesDebug, then if not there, to C:\GlobalAssemblies
In RELEASE mode, since it deletes everything from C:\GlobalAssembliesDebug, it only looks to C:\GlobalAssemblies. The reason I want this is so that released builds aren't built against anything that was temporarily changed in my solution.
It is easy to load and unload projects without much effort.
Of course, it isn't perfect. The debugging experience is not as nice as a project reference. (Can't do things like "go to definition" and have it work right), and some other little quirky things.
Anyways, that's where I am on my attempt to make things work for the best for us.
We have one gigantic solution on the source control, on the main branch.
But, every developer/team working on the smaller part of the project, has its own branch which contains one solution with only few projects which are needed. In that way, that solution is small enough to be easily maintenaced, and do not influence on the other projects/dlls in the larger solution.
However, there is one condition for this: there shouldn't be too much interconnected projects within solution.
OK, having digested this information, and also answers to this question about project references, I'm currently working with this configuration, which seems to 'work for me':
One big solution, containing the application project and all the dependency assembly projects
I've kept all project references, with some extra tweaking of manual dependencies (right click on project) for some dynamically instantiated assemblies.
I've got three Solution folders (_Working, Synchronised and Xternal) - given that my source control isn't integrated with VS (sob), this allows me to quickly drag and drop projects between _Working and Synchronised so I don't lose track of changes. The XTernal folder is for assemblies that 'belong' to colleagues.
I've created myself a 'WorkingSetOnly' configuration (last option in Debug/Release drop-down), which allows me to limit the projects which are rebuilt on F5/F6.
As far as disk is concerned, I have all my projects folders in just one of a few folders (so just one level of categorisation above projects)
All projects build (dll, pdb & xml) to the same output folder, and have the same folder as a reference path. (And all references are set to Don't copy) - this leaves me the choice of dropping a project from my solution and easily switching to file reference (I've got a macro for that).
At the same level as my 'Projects' folder, I have a 'Solutions' folder, where I maintain individual solutions for some assemblies - together with Test code (for example) and documentation/design etc specific to the assembly.
This configuration seems to be working ok for me at the moment, but the big test will be trying to sell it to my colleagues, and seeing if it will fly as a team setup.
Currently unresolved drawbacks:
I still have a problem with the individual assembly solutions, as I don't always want to include all the dependent projects. This creates a conflict with the 'master' solution. I've worked around this with (again) a macro which converts broken project references to file references, and restores file references to project references if the project is added back.
There's unfortunately no way (that I've found so far) of linking Build Configuration to Solution Folders - it would be useful to be able to say 'build everything in this folder' - as it stands, I have to update this by hand (painful, and easy to forget). (You can right click on a Solution Folder to build, but that doesn't handle the F5 scenario)
There is a (minor) bug in the Solution folder implementation which means that when you re-open a solution, the projects are shown in the order they were added, and not in alphabetical order. (I've opened a bug with MS, apparently now corrected, but I guess for VS2010)
I had to uninstall the CodeRushXPress add-in, because it was choking on all that code, but this was before having modified the build config, so I'm going to give it another try.
Summary - things I didn't know before asking this question which have proved useful:
Use of solution folders to organise solutions without messing with disk
Creation of build configurations to exclude some projects
Being able to manually define dependencies between projects, even if they are using file references
This is my most popular question, so I hope this answer helps readers. I'm still very interested in further feedback from other users.

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