[Bug c++/91382] New: Missing pedwarn when using [[maybe_unused]] in C++14

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91382

            Bug ID: 91382
           Summary: Missing pedwarn when using [[maybe_unused]] in C++14
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

void foo([[maybe_unused]] int i) { }

$ ./cc1plus -quiet q.C -std=c++14 -pedantic -Wall -W
# nothing

But maybe_unused came in C++17, so we ought to pedwarn in <C++17 modes.  Other
attributes most likely have the same issue.