[Rd] Making headers self-contained for static analysis

[Lionel Henry]

People have let me know that the attachment didn't make it through.
Do patches get filtered out?

Please find it there:
https://github.com/lionel-/r-svn/commit/e3de56798b1321a3fa8688a42bbb73d763b78024.patch

I'm also happy to post it on the bugzilla if that makes sense.

Best,
Lionel

On 3/16/23, Lionel Henry <lionel using posit.co> wrote:
> Hello,
>
> I started using clangd to get better static analysis and code
> refactoring tooling with the R sources (using eglot-mode in Emacs, it
> just works once you've generated a `compile_commands.json` file with
> `bear make all`). I noticed that the static analyser can't understand
> several header files because these are not self-contained. So I went
> through all .h files and inserted the missing includes, cf the
> attached patch.
>
> Making the headers self-contained has consequences for the .c or .cpp
> files that include them. In the case of C files, the only downside I
> see is that it might cause users to accidentally rely on indirect
> inclusion of standard headers, instead of directly including the
> header to make the dependency explicit as would be good practice.
> This doesn't seem like a big deal compared to the benefits of enabling
> static analysis.
>
> However in the case of C++ that's more problematic. We don't want to
> include the C headers because that would pollute the global namespace
> and users might prefer to import the missing symbols (`size_t` and
> `FILE`) selectively. Also that wouldn't help static analysis within
> the header files since the analysers use the C path. So I have guarded
> inclusion of standard C headers behing a `__cplusplus` check.
>
> If that makes sense, would R core consider applying the attached patch
> to the R sources?
>
> Best,
> Lionel
>