I'm an experienced C++ developer, Ada newbie, trying to port a mixed C and Ada legacy codebase to GNAT Studio. I want to compile the C and Ada sources to multiple static libraries and use them from a GtkAda executable. Actually it's a pretty complicated situation as I'll detail below.
Initially I was going to ask what is the GNAT Studio equivalent of a workspace or solution file, because I wasn't finding it. But just before posting that question, I stumbled upon the documentation section for "aggregate project" in .gpr file. Yahtzee. ("Aggregate" was the one synonym I hadn't thought to google for!)
But, I still want to see this in use before I'm comfortable using it from scratch. My learning style is I learn best from examples. First I mimic, then I understand. The syntax seems simple enough, but the documentation on aggregate projects doesn't (for instance) devote any words to common conventions like whether the .gpr file is usually mixed in with the sources or at a directory level above, etc.
And the same applies to linking and calling the C code from the Ada code (or even calling the Ada lib from the exe, for that matter). As a C++ programmer (and also C#) I'm familiar with the issues (e.g. name mangling and ABI/calling conventions) with cross-language marshaling. I still want to look at a big (real) Ada project that does it.
Finally, I read that the aggregate project feature in GNAT Studio supports the same source file being included - perhaps with different interpretations - in multiple different projects. That's good news because this legacy codebase uses that model heavily to actually build EPROM (firmware) images for multiple similar-but-different circuit boards. I actually want to run all of them within the one Gtk executable (it will be a simulator or emulator, depending how you term it), so I'll have multiple different Ada libs, that used to build independent .hex or .bin files, now being combined into one executable.
Actually it's even more complicated than that. There's two legacy codebases, the second for a still-old but newer generation of the equipment, and I'm hoping to put both of those together too. (You'd select which version of the equipment you want to simulate with a radio button.) The codebases for those have different versions of the same files. If I had to I can just make that two different GtkAda programs.
Because of both combining what were multiple different EPROM images into one executable, and the possibility of combining two similar-but-different sets of EPROM images, I'm wondering if and how namespace collisions are manageable in an aggregate project. I solved a similar problem combining C++ codebases associated with these two equipment generations into one application by segregating the codebases by DLL. Since a DLL only exports the names you tell it to, it doesn't matter if the same name is used for different things internally; they can still be linked into the same program.