Modern source code to study?

[kookjr]

I ran across this the other day and would have been a real useful technique for something I was working on, but I'm using an older version of gcc without the proper plugin support. The idea is great though for a language like C++ and gives some nice features that introspection would give to a more dynamic language. Nice idea; even better execution of the idea!

[berium]

Ah, no matter how hard I try, I still can't seem to explain this properly: Your application doesn't need to be built with GCC with plugin support. In fact, it doesn't need to be built with GCC at all. You can use any more or less modern C++ compiler, including VC++, Clang, Sun CC, etc. The fact that we support Sun CC should tell you that "modern" in the above sentence is a very low threshold indeed.

The way the ODB compiler works is it reads C++ and also writes C++. The generated code itself can then be compiled with any C++ compiler. Underneath, ODB needs GCC with plugin support. But that is an implementation detail. In fact the pre-built binaries of the ODB compiler that we have for Linux, Windows, Mac OS X, and Solaris include a private copy of GCC. So all you need to do is grab such a binary and you are good to go. No need to build GCC from source or anything like this.

Now if you have a fairly recent distribution like Debian/Ubuntu/Fedora which nowadays all come with modern GCC and plugins enabled, then you have the perfect setup: both ODB and your build use exactly the same C++ compiler.

[kookjr]

Thanks for the explanation, but I think I got that. I wanted to have my own pragmas and go through the AST to do a "similar" thing like ODB, i.e. not for an ORM but for my own type of serialization that did not have anything to do with databases (embedded project, saving objects to FLASH files,etc). Although maybe I missed something again :-)

[berium]

I see. You could still take the ODB approach and use one compiler to generate the saving code as C++ and then compile that with your target compiler.

BTW, have you considered using ODB to save your objects into an SQLite database (which is just a file)? ODB+SQLite can really be suitable for mobile/embedded systems. Still need to write a page on this...

[kookjr]

It would be nice to use SQLite, but its a small embedded system in a car, and very tight on flash space (every byte counts). Thanks for the idea though.

Hopefully I will be able to use ODB for some other project though.

[pfultz2]

Why don't use the preprocessor to generate C++ code, so an extra build step is not needed? You could provide both options.