[Bug c/86134] New: earlier error causes followup diagnostic about unknown -Wno-* options

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86134

            Bug ID: 86134
           Summary: earlier error causes followup diagnostic about unknown
                    -Wno-* options
           Product: gcc
           Version: 8.1.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

> echo 'int main(){' | gcc -S -x c -Wno-unknown-warning-option -
<stdin>: In function ‘main’:
<stdin>:1:1: error: expected declaration or statement at end of input
<stdin>: At top level:
cc1: warning: unrecognized command line option "-Wno-unknown-warning-option"
[enabled by default]

compared to

> echo 'int main(){}' | gcc -S -x c -Wno-unknown-warning-option -

with -Werror the diagnostic on the unrecognized command line option is an
error as well.