[Bug driver/97058] New: invalid "cc1: warning: '-Werror=' argument '-funroll-completely-grow-size' is not valid for C"

[Bug driver/97058] New: invalid "cc1: warning: '-Werror=' argument '-funroll-completely-grow-size' is not valid for C"

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97058

            Bug ID: 97058
           Summary: invalid "cc1: warning: '-Werror=' argument
                    '-funroll-completely-grow-size' is not valid for C"
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: driver
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu

Compiler output:
$ echo '' > tst.c
$ gcc -Wno-multichar -funroll-completely-grow-size -c tst.c
cc1: warning: '-Werror=' argument '-funroll-completely-grow-size' is not valid
for C
$ gcc -Wno-multichar -funroll-completely-grow-size -xc++ -c tst.c
cc1plus: warning: '-Werror=' argument '-funroll-completely-grow-size' is not
valid for C++

$ gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest/bin/gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r11-3201-20200915093938-g0f079e104a8-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/11.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r11-3201-20200915093938-g0f079e104a8-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.0.0 20200915 (experimental) (GCC)

[Bug driver/97058] invalid "cc1: warning: '-Werror=' argument '-funroll-completely-grow-size' is not valid for C"

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97058

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
You're not supposed to use this flag but the behavior is indeed weird.  The
last part "not valid for C/C++" is due to the fact the option is not marked
for any language:

funroll-completely-grow-size
Undocumented Var(flag_cunroll_grow_size) Optimization
; Internal undocumented flag, allow size growth during complete unrolling

but the '-Werror=' argument part is really odd ;)

[Bug driver/97058] invalid "cc1: warning: '-Werror=' argument '-funroll-completely-grow-size' is not valid for C"

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97058

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2023-06-15

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed, I just noticed this warning too.