[Bug c/68833] New: -Werror=format issues an error now

[sirl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68833

            Bug ID: 68833
           Summary: -Werror=format issues an error now
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sirl at gcc dot gnu.org
  Target Milestone: ---

This little example issues an error now on trunk r231490:

# gcc -c -Werror=format -x c - </dev/null
cc1: error: missing argument to '-Wformat='

If this is intentional, the documentation for -Wformat should be updated.