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RE: [cdt-dev] First gotcha with add/exclude children of FFS

So, you know. The more I think about what you guys are saying, I'm realizing that the EFS solution probably is the right one. The objective should be to turn the IResource tree into a logical project view and to remove all notions that it represents physical file layout. That unfortunately starts with the .project and .cproject files, but I think there are tricks we can do there. The .settings may be harder but let me sleep on that.
 
At any rate, this has piqued my interest again and I'll work on reviving it and see where it goes. I'll try to get a prototype working by EclipseCon so we can talk about it more concretely.
 
Cheers,
Doug


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Brunauer, Walter
Sent: Monday, February 18, 2008 8:53 AM
To: CDT General developers list.
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

Hi Warren,
 
well, the confusion my origin from the different meanings of what project setup is: for me, project setup is not equal to build setup. I.e., on our projects, the build setup is an independent step from the project setup. We intentionally separated this to overcome all kind of issues you obviously experienced as well. And this is how we see it:
 
1. Create a project at the desired location (everything beneath this root location is part of the project, but it can be an empty project just as well with linked resources added to it later). By default, the build setup is identical to the project content (there is one build target, linking/archiving everything together).
 
2. If (a) specific build setup(s) are needed, it is possible to specify as many build targets with arbitrary contents as desired. This approach separates the physical file system layout from logical build layouts, and it even works beyond project boundaries. IOW, no matter from where source files are pulled in (the same projects, nested projects, outer projects, sibling projects), one is able to specify any build setup exactly are needed, as long as all source files are known to Eclipse (as resources).
 
HTH,
 
Walter


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Warren.Paul@xxxxxxxxx
Sent: Freitag, 15. Februar 2008 14:51
To: cdt-dev@xxxxxxxxxxx
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

Hi Walter,
 
I forgot all about the absolute paths issue with linked resources.  I'll update the wiki.
 
I'm a bit confused about your comment about this not being a project setup issue.  We have our own builder as well, and it will happily build whatever the build description says, whether those files are under the project root or not.  We even have our own project explorer view which shows a logical representation of the project rather than the physical file system layout.  But we still run into a lot of issues when files are not under the project root - that is, when you can't get an IFile for them.
 
We have a wide range of user types from small application developers to large system developers.  In many cases, a users code base consists of hundreds of directories with thousands of source files.  In such a source base, there are many hundreds of build artifacts and almost as many "logical projects".  It is a huge problem for these users to be able to create projects currently.  They will typically have a few projects going at a time, but many times the natural project root for all of them will be the same.  We've found ways to work around some of the other issues, but not this one.  It sounds like perhaps you guys have found a way.  Could you elaborate on how you setup your projects?
 
Thanks,
Warren


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of ext Brunauer, Walter
Sent: Friday, February 15, 2008 1:56 AM
To: CDT General developers list.
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

Hi Warren,
 
FWIW, you did not mention anything about linked resources and absolute paths these persist in the .project file by default. Again a big issue around linked resources in combination with sharing project within a team (even without team support), and one more reason why they appear to be so cumbersome to handle. To me it seems many times one has to unsell linked resources to users: Whereas linked resources are (kind of!) nice for evaluation purposes (because, yes, in this case you might not want to pollute your sources), as soon as you start serious development, you run into all kind of troubles. The hurdle to get everything right from the beginning is overwhelming for novices (e.g. its not possible to change a linked resource to use a variable later). Sorry, I don't know how to add this to the Wiki page...
 
Having said that, the scenario you describe is really about having the flexibility around build and indexer setup, not around project setup, IMO.
 
It's rather classic: users have common code they want to reuse in multiple applications - so they create one or a set of libraries out of it, within one or a set of projects. Of course, indexing should be able to handle only code going into these libraries, and optionally ignore the rest. Then, they create their application projects, which use the binary artifacts of the library project(s). Now it would be great if they would have automatic support for application linkage specification, i.e. some nice wizard or UI allowing to select the library binaries of other projects to be linked in, without the need to specify it manually in the linker options. And probably also desired: during application code development, the public API's of all used library projects should be the only thing they see WRT code completion, etc. I guess, some UI would be needed for this as well.
 
And now think of all developers in the world. Wouldn't it be great to give as many of them the freedom to choose how to achieve this? Either everything in one project, or one project per build artifact, or one project per module/application/product, or with nested projects... its possible. Our commercial IDE based on CDT supports all this, and we did not have to provide some EFS or work with linked resources. Well, we had to override the build system, and this is IMO the place to solve this in CDT as well.
 
Again, I don't see anything specific to project setup. The issue around having the source tree polluted with project files - I don't think this is the big thing. I would not leave the Eclipse path in this area at all and allow to separate the project file from the project location. Its a very general paradigm of Eclipse, and I am pretty sure doing everything differently will generate lots and lots of problems in all kind of areas (probably much more than you already identified), unless you make it a new Eclipse way (add/change this in the platform, not in CDT, that is).
 
Just my 2 or 3 cents again,
 
Walter


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Warren.Paul@xxxxxxxxx
Sent: Donnerstag, 14. Februar 2008 23:35
To: cdt-dev@xxxxxxxxxxx
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

I've updated the Wiki page http://wiki.eclipse.org/CDT:Flexible_Project_Structure with some more thoughts on the issue.  It would be great to get feedback from other CDT users - both those shipping C/C++ IDE's and end users.  You'll see that I'm not convinced that the linked resources route is a viable option.  Maybe we can get the platform team involved in the discussion to help find the best route forward.
 
Thanks,
Warren
 


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of ext Schaefer, Doug
Sent: Friday, January 25, 2008 11:15 AM
To: CDT General developers list.
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

I guess what my investigation has shown me that the EFS solution and linked resources are pretty much identical. I really noticed this when trying to figure out how to persist the adds and found myself wishing I could add that to the .project file just like linked resource are. And they are....
 
I think all the issues that we have with linked resources would be equally as bad with the EFS solution, possibly worse because the EFS adds are hidden. The CVS one is a great example. I really doubt CVS would work with the EFS solution either. And I don't want us to think EFS would be better since it's not in the platform where we'll have a battle getting changes. Any platform changes required to make linked resource work correctly would also need to be done for EFS.
 
So my hope is to save the effort at implementing the add/remove functionality since I believe that's already there with linked/hidden resources. We can then focus on making linked resources work where we need them and improving the workflows. But this really needs to start now.
 
So, Warren, you've somewhat started a list of workflows that we'd like to support with this solution. This is a great place to start. I've created a Wiki page to start capturing these. Please feel free to add more information, especially to the workflow section. When we have that we may get a better idea of which of the two solutions will work best.
 
    http://wiki.eclipse.org/CDT:Flexible_Project_Structure
 
Thanks,
Doug

 

From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Warren.Paul@xxxxxxxxx
Sent: Friday, January 25, 2008 11:22 AM
To: cdt-dev@xxxxxxxxxxx
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

We've been working on Eclipse/CDT based products for about three years now.  I'm sorry to say that the project model is still not satisfactory for our purposes.  We've tried many angles, but are still stuck with some pretty serious limitations.  I've volunteered to investigate the EFS route to see if it will help at all.  Based on this thread I'm assuming it won't.
 
Let me give you a brief overview of how our users work, and then discuss the problem we've run into.  I don't think any of this is specific to our users BTW.
 
Most of our users have existing code bases.  They simply want to "import" it into the IDE.  Others will create new projects from our templates.  The new projects are created in the workspace.  Imported projects could be anywhere in the file system.  Often times they will import several projects from the same source tree.  This is where our biggest problem is.  Let's say the source base looks like this:
 
C:\MyProjects\Project1\...
C:\MyProjects\Project2\...
C:\MyProjects\Common\...
 
Because both projects share code in the Common directory, the logical root project directory for both Project1 and Project 2 is C:\MyProjects\.  But in Eclipse you can't have two projects with the same root.  This is where the .project and .cproject files are created.  So currently our users would import Project1 with the natural root (C:\MyProjects\), but Project2 has to be rooted at C:\MyProjects\Project2\.  This means that any source/headers from the common directory are not under Project2.  This means those files are not in the project explorer for that project, are not indexed, etc..  We logged this against the platform - https://bugs.eclipse.org/bugs/show_bug.cgi?id=78438.  Basically if you put the .project file anywhere, but have a project root attribute, this would cease to be a problem.
 
Our first product actually always created the .project in the workspace, and for imported projects, would create links to files and folders.  We ran into so many issues with this that we had to change the model.  I don't recall all of the issues, but here's a list of some:
 
- Version control simply didn't work at all
 
- You can't make file system changes with links.  For example, if you want to rename a file or folder, or move a file around, you can't do this with linked resources.  It only changes the link itself, not the underlying resource.
 
- Creating new resources in a project with links is confusing at best.  Let's say you have a project with a linked folder and file at the root.  If you create a new file or folder at the root, it is created in the workspace, not where the other folder/file are in the file system.  But if you create a new file under the linked folder, it gets created where you'd expect.
 
- The location of the .project/.cproject files are problematic.  Some users will want to keep these in version control, while others won't.  Those that do want them created in the source tree, but those that don't want them elsewhere, like the workspace.  I forget now why this was a problem with linked resources, but there was something weird going on there.
 
I suppose it's worth noting that the last time we really looked at this was in Eclipse 3.2, so some of this may have been fixed by now.  But I doubt it.  In general linked resources are second class citizens.  Some IResource API's just don't work for linked resources.  Just search for references to IResource#isLinked for "special handling".  I suspect that we'll run into similar issues with EFS though - see getLocation vs getLocationURI.
 
We also have the same issue that Doug is trying to address (hiding some branches in a source tree).  This is much less of an issue for us though.  You can already reduce the scope of the indexer and the build.  The only real issue for us is for a very large source tree, you're going to get IResource's for everything, which slows things down quite a bit.  There is actually somewhat of a problem in reducing the indexer scope - see https://bugs.eclipse.org/bugs/show_bug.cgi?id=178159.
 
The hidden attribute addition sounds promising for hiding resources under the project root, but doesn't really do anything to add flexibility to the contents of a project.  EFS sounds like it would though.  What I mean by that is, having resources under a project that are real resources, not linked, but that don't live under the project root in the file system.  I've just started looking into EFS, so maybe it's a bit of wishful thinking at this point, but I'm hoping we could create a project anywhere, and when we create it we pass the URI location from our own EFS.  Then when asked for the children, we could return URI's for files from anywhere in the file system, or on other machines even.  This would seem to hold the potential for working around the issues listed above.  We'd basically have an EFS map from what we want under a project to the actual file system.
 
So hopefully some of the experts can chime in here.  Is my hope for EFS unrealistic?  Is there a different approach we should look at?
 
Thanks,
Warren
 


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of ext Brunauer, Walter
Sent: Friday, January 25, 2008 1:47 AM
To: CDT General developers list.
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

Hi,
 
after reading this rather long thread, I'll decided to throw in my personal opinion.
 
I consider this approach to work against one of the most general Eclipse platform paradigms, where a project is defined to be a root directory and everything in it. IMO, the more workarounds are introduced against this paradigm, the more problems will be faced, and the more incompatibilities (or at least unawarenesses) created.
 
Isn't the whole problem you try to solve here rather about what files should go into the build (and probably into the indexer) than what files are part of a project? I understand that CDT has no separation of what a project and what the build input is (well, IIRC one can exclude specific files from the build, but in general, the project content defines the build input, right?).
 
In our commercial IDE, we separated this. This not only introduced much more powerful build setup capabilities in general, but especially enabled users to setup build artifacts with arbitrary contents (think of sources being compilable with different compiler flags for different build artifacts, build input exclusion patterns, build input from all over the workspace, multiple build artifacts within the same project, reusable build artifacts accross project boundaries, etc., etc., etc.). BTW, we call this build system flexible managed build - because that's what it is:-)
 
Of course, one can setup CDT projects as of today to exactly contain what is desired (with the help of linked resources). However, I find linked resources to be cumbersome and error prone, though many of our customers start out with them during evaluation as well, mostly because they are looking for a way to achieve what they did in the past with other non-Eclipse based IDEs, but sooner or later I know of lots of them realizing its much easier to use the features of our flexible build system instead, especially if projects need to be shared in a team. And now think of virtual file systems, the potential complexity of these, hidden assumptions, restrictions, etc. Sounds worse than linked resources to me.
 
I guess, the point I am trying to make is: whatever you decide to do, make it understandable and transparent (and of course as simple as possible to use) for the user.
 
As said, just my 2 cents,
 
Walter


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Schaefer, Doug
Sent: Donnerstag, 24. Jänner 2008 23:17
To: CDT General developers list.
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

Jogging through the code, it really looks like the HIDDEN feature is what I was looking for. What I haven't found yet is UI to make a resource hidden or a navigator filter to show hidden resources (in case you want to bring them back). Is this planned?
 
Assuming we have the core features available to link in and hide resource, I think we still have workflow issues that need to be addressed. I like Ken's idea of a file that controls the linking/hiding. We could have an import/export mechanism for setting up projects based on this file. A nice wizard for creating the file would also be good, similar to the way the way the export file system wizard works.
 
Given this, we may be further along than we thought (BTW, the hidden stuff seems to have been added in 3.4 M4).
 
Cheers,
Doug


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Schaefer, Doug
Sent: Thursday, January 24, 2008 2:51 PM
To: CDT General developers list.
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

Thanks Michael/Szymon,
 
Is there a bug describing the isHidden feature?

Doug


From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Michael Valenta
Sent: Thursday, January 24, 2008 11:37 AM
To: cdt-dev@xxxxxxxxxxx
Subject: RE: [cdt-dev] First gotcha with add/exclude children of FFS

Doug et al,

Szymon is really the person you want to bug on this but I'll throw in my 2 cents ;-)  First, I have to say that a solution at the IResource level (e.g. using linked resources and the new hidden folder support) is infinitely better from a repository provider perspective than an EFS based solution.  You may not get all the Team support you want at the IResource level but a solution at the EFS level would certainly break the existing CVS client since the CVS client isn't EFS aware to any great extent. For instance, if you tried to hide a folder using EFS, the CVS client would probably try and recreate it the next time you performed a Team>Update. It is also important to note that the Platform does not provide all the hooks required by repository providers and I know of at least one provider that has resorted to using it's own EFS implementation under projects that are mapped to that provider to get the capabilities it requires. I think it is important that tooling in Eclipse stick to using the IResource layer as the layer they operate on and let the repository provider (or any other tooling whose responsibility it is to manage the available files) control the underlying file system. If there are shortcomings or enhancements required then you should push to get them in at the IResource level.

As for the current state of Team support for linked resources, I think the best approach is to enumerate some specific scenarios of how you see linked resources and exclusions working with descriptions of what you need to do today to get Team support and what you would like to see. It is also important to know if you expect all the links to come from the same repository (or at least repository type) or whether a project could contain content from different repository types (obviously the later would be more difficult to accommodate than the former).

Hope this helps,
Michael