The source code of our application is hundreds of thousands of line, thousands of files, and in places very old - the app was first written in 1995 or 1996. Over the past few years my team has greatly improved the quality of the source, but one issue remains that particularly bugs me: a lot of classes have a lot of methods fully defined in their header file.
I have no problem with methods declared inline in a header in some cases - a struct's constructor, a simple method where inlining measurably makes it faster (we have some math functions like this), etc. But the liberal use of inlined methods for no apparent reason is:
- Messy
- Makes it hard to find the implementation of a method (especially searching through a tree of classes for a virtual function, only to find one class had its version declared in the header...)
- Probably increases the compiled code size
- Probably causes issues for our linker, which is notoriously flaky for large codebases. To be fair, it has got much better in the past few years, but it's not perfect.
That last reason may now be causing problems for us and it's a good reason to go through the codebase and move most definitions to the source file.
Our codebase is huge. Is there an automated tool that can do (most of) this for us?
Notes:
- We use Embarcadero RAD Studio 2010. In other words, the dialect of C++ includes VCL and other extensions, etc.
- A few headers are standalone, but most are paired with a corresponding .cpp file, as you normally would. Apart from the extension the filename is the same, i.e., if there are methods defined in X.h, they can be moved to X.cpp. This also means the tool doesn't have to handle parsing the whole project - it could probably just parse individual pairs of .cpp/.h files, ignore the includes, etc, so long as it could reliably recognise a method with a body defined in a class declaration and move it.
You might try Lazy C++. I have not used it, but I believe it is a command line tool to do just what you want.
If the code is working then I would vote against any major automated rewrite.
Lots of work could be involved fixing it up.
Small iterative improvements over time is a better technique as you will be able to test each change in isolation (and add unit tests). Anyway your major complaint about not being able to find the code is not a real problem and is already solved. There are already tools that will index your code base so your editor will jump to the correct function definition without you having to search for it. Take a look at ctags or the equivalent for your editor.
Messy
Subjective
Makes it hard to find the implementation of a method (especially searching through a tree of classes for a virtual function, only to find one class had its version declared in the header...)
There are already tools available for finding the function.
ctagswill make a file that allows you to jump directly to the function from any decent editor (vim/emacs). I am sure your editor if nto one of these has the equivalent tool.Probably increases the compiled code size
Unlikely. The compiler will choose to inline or not based on internal metrics not weather it is marked inline in the source.
Probably causes issues for our linker, which is notoriously flaky for large codebases. To be fair, it has got much better in the past few years, but it's not perfect.
Unlikely. If your linker is flakey then it is flakey it is not going to make much difference where the functions are defined as this has no bearing on if they are inlined anyway.
XE2 includes a new static analyzer. It might be worthwhile to give the new version of C++Builer's trial a spin.
You have a number of problems to solve:
- How to regroup the source and header files ideally
- How to automate the code modifications to carry this out
In both cases, you need a robust C++ parser with full name resolution to determine the dependencies accurately.
Then you need machinery that can reliably modify the C++ source code.
Our DMS Software Reengineering Toolkit with its C++ Front End could be used for this. DMS has been used for large-scale C++ code restructuring; see http://www.semdesigns.com/Company/Publications/ and track down the first paper "Case Study: Re-engineering C++ Component Models Via Automatic Program Transformation". (There's an older version of this paper you can download from there, but the published one is better). AFAIK, DMS is the only tool to have ever been applied to transforming C++ on large scale.
This SO discussion on reorganizing code addresses the problem of grouping directly.
来源：https://stackoverflow.com/questions/8852502/tool-to-parse-c-source-and-move-in-header-inline-methods-to-the-cpp-source-fi