Setting up a large software system in Delphi

Question

We have a software package which is about 16 years old. It's gone through just about every version of Delphi (besides .NET ones). Over the years, things have become very confusing when it comes to cross-referencing and keeping proper setup for additional packages (like third-party libraries). I was wondering if there is some standard practice when it comes to keeping large projects (and groups of projects) like this organized.

So to explain the current setup...

This is a multi-application system. Meaning, there are 12 executable projects (and a few DLL and service projects) involved. We also keep things in SourceSafe and multiple developers work on the same code on different computers. All of these projects are more-so dumped into a central folder. The "Root" folder contains THE major EXE project (along with about 20 folders, all containing units and forms) and it almost seems like an endless hierarchy of folders and files. This one project alone has half a million lines of code involved.

Then all the additional applications aren't necessarily separated properly from this major project. Each of these projects has its own folder based in the main project's root.

The two major concerns of mine are:

• How to properly set up the DCU files so that they aren't mixed in with the projects? DCU's should NOT be placed in the SourceSafe (and any similar file, for that matter) or otherwise, any file compiled from the project. Visual SourceSafe makes files read-only when they're not checked out, and DCU files (and EXE files and more) cannot be written to in this case. So how to properly separate any of such file to a remote location to avoid any mixture with the source code?
• How to properly set up packages and libraries? We have the following:
  • QuickReports 5.05
  • NativeJpg library V302 -
  • Another anonymous reporting library
  • Our own component package, which requires QuickReports, NativeJpg, and the other anonymous library

All 4 of those libraries are stored in completely different places of each computer, and need some centralization. The biggest pain of setting up each new developer's computer is locating these from the lead developer's computer and copying them to the same place on each other computer (and making sure the library path is correct, etc.).

We also need to keep completely separate environments for different versions of Delphi on the same computer. This means a copy of the projects on each computer, a copy of packages and libraries on each computer, a copy of the projects and packages and libraries in the SourceSafe, etc. Each computer needs to have an identical setup. We already utilize environment variables to direct our projects where to look for certain project files (and libraries).

Another new concern: XE2 introduces 64bit capabilities. We don't plan on 64bit compiling yet, but we certainly will in the future. How do I properly differentiate 32bit from 64bit in all these projects?

What I'm really asking for is a reference to a good tutorial on how to optimize such an environment and keep it organized the best. I don't expect anyone to take the time and answer all this in the question. The projects are over 15 years old, have had the hands of 200+ developers from around the world in it, and has a LOT of cross-referencing between projects. For example, one project may use a unit from another project, and vice-versa. I personally don't like this concept, but I also didn't design it to begin with. I've been given the task to get this system organized and thoroughly documented how to set up Delphi on a new computer for new developers to work on our projects. As I'm looking at our projects (as I'm not necessarily a developer of the system, but am being pulled into development), I'm seeing a lot of confusion in how the code is organized.

I am assuming that possibly Embarcadero has some guidelines and standards on setting up such an environment?

Answer 1

Location of DCU files

Regarding the DCUs that are the output of the compilation process, you should specify a DCU output directory in each project file. The default value for this, in the latest version of Delphi would be fine: .\$(Platform)\$(Config). This results in sub-folders of the project directory like this: Win32\DEBUG or Win64\RELEASE.

If you set-up your project files using option sets then you will be able to control this setting (and all others) from a small number of option files.

Location of 3rd party code

You should always use 3rd party library as code. If the vendor charges more to receive the library as code, pay up. Once you have done so you simply include the source code into your version control system (VCS) and treat it largely the same way as you treat your own code. I say largely because you should avoid modifying it.

Once you have all your code in the VCS then you can put the entire source code onto a new machine with a single checkout operation.

Organisation of your projects

I personally have a strong aversion to using compiler search paths. I don't use them and include every unit that is required in a project in the .dpr file.

If you do use search paths then you make it impossible to work on variant projects.So for example, suppose you have a client that has discovered a bug in the version of the software you released 2 years ago. You would like to address that bug by releasing an upgrade to the 2 year old version of the software. It is perfectly plausible that asking them to upgrade to the latest version is not viable. Perhaps they have not paid for the upgrades. Perhaps the full upgrade has breaking changes that they do not want to tackle right now. A perfect example would be all the Delphi developers still using Delphi 7.

Now, having motivated the scenario, how would you create a build environment for the 2 year old project? If you are using search paths then they will refer to today's libraries. You would be forced to change your search path, or copy the old libraries over the top of today's libraries.

That entire headache is trivially side-stepped by not using search paths and by including all your source in the VCS.

What you should be aiming for is to be able to checkout any historic version of your program and have it build immediately. You should be able to do this with full confidence that you are building identical software to what was built at the time that version was released. This also requires you to have build automation but I can't imagine you are lacking that for a project of this size.