[Bug c++/93506] New: Create hybrid of -I and -isystem that is like -I but deactivates warnings

[fiesh at zefix dot tv]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93506

            Bug ID: 93506
           Summary: Create hybrid of -I and -isystem that is like -I but
                    deactivates warnings
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fiesh at zefix dot tv
  Target Milestone: ---

Being guilty of abusing -isystem a lot to silence warnings in third-party
libraries, it would be great if there were a spin off of -I that ignored
warnings just like -isystem does but otherwise behaves like -I.

(An argument that is brought up sometimes, namely that third-party libraries
should fix their warnings, isn't really valid I believe.

For example, constexpr variables became implicitly inline in C++17.  Before
that, one had to define them in translation units.  So libraries remaining
pre-C++17 compatible will want to do that, while projects that compile in C++17
might prefer warnings about deprecated things being done.

Also, from a practicality point of view, it is simply not a meaningful
argument.)