[Bug c/65445] New: Improve [-W...] display for -Wformat

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65445

            Bug ID: 65445
           Summary: Improve [-W...] display for -Wformat
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org

Currently, the -Wformat suboptions (-Wformat-contains-nul, etc.) are shown as
"[-Wformat=]" - it would be useful to have the individual flag (such as
[-Wformat-contains-nul]) instead.

Originally reported as PR 65040 comment 18