[Bug libstdc++/47058] New: "--enable-maintainer-mode --disable-werror" wrongly upgrades warnings to errors in libstdc++

[John.Tytgat at aaug dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47058

           Summary: "--enable-maintainer-mode --disable-werror" wrongly
                    upgrades warnings to errors in libstdc++
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: John.Tytgat@aaug.net


Using gcc 4.6trunk r168215, target arm-unknown-eabi, newlib 1.19.0, binutils
2.21.

Configured with: --target=arm-unknown-eabi
--prefix=/home/joty/projects/gccsdk/riscos7/cross
--with-gmp=/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/installed-libs-for-cross-gcc
--with-mpfr=/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/installed-libs-for-cross-gcc
--with-mpc=/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/installed-libs-for-cross-gcc
--with-ppl=/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/installed-libs-for-cross-gcc

--with-cloog=/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/installed-libs-for-cross-gcc
--disable-threads --disable-multilib --disable-shared --with-newlib
--enable-maintainer-mode --disable-werror --enable-interwork --disable-nls
--disable-libquadmath --enable-checking=release --enable-languages=c,c++

Mind "--enable-maintainer-mode --disable-werror" being used.

And this still results in a -Werror during libstdc++ building, which results
into:

--8<--
ln -s
/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/srcdir/gcc/libstdc++-v3/config/locale/generic/ctype_members.cc
. || true
/bin/bash ../libtool --tag CXX   --mode=compile
/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/./gcc/xgcc
-shared-libgcc
-B/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/./gcc
-nostdinc++
-L/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libstdc++-v3/src
-L/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libstdc++-v3/src/.libs
-nostdinc
-B/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/newlib/
-isystem
/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/newlib/targ-include
-isystem
/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/srcdir/gcc/newlib/libc/include
-B/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libgloss/arm
-L/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libgloss/libnosys
-L/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/srcdir/gcc/libgloss/arm
-B/home/joty/projects/gccsdk/riscos7/cross/arm-unknown-eabi/bin/
-B/home/joty/projects/gccsdk/riscos7/cross/arm-unknown-eabi/lib/ -isystem
/home/joty/projects/gccsdk/riscos7/cross/arm-unknown-eabi/include -isystem
/home/joty/projects/gccsdk/riscos7/cross/arm-unknown-eabi/sys-include    
-I/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libstdc++-v3/include/arm-unknown-eabi
-I/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libstdc++-v3/include
-I/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/srcdir/gcc/libstdc++-v3/libsupc++
 -fno-implicit-templates -Wall -Wextra -Wwrite-strings -Wcast-qual -Werror
-fdiagnostics-show-location=once  -ffunction-sections -fdata-sections  -g -O2
-c -o ctype_members.lo ctype_members.cc
libtool: compile: 
/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/./gcc/xgcc
-shared-libgcc
-B/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/./gcc
-nostdinc++
-L/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libstdc++-v3/src
-L/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libstdc++-v3/src/.libs
-nostdinc
-B/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/newlib/
-isystem
/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/newlib/targ-include
-isystem
/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/srcdir/gcc/newlib/libc/include
-B/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libgloss/arm
-L/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libgloss/libnosys
-L/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/srcdir/gcc/libgloss/arm
-B/home/joty/projects/gccsdk/riscos7/cross/arm-unknown-eabi/bin/
-B/home/joty/projects/gccsdk/riscos7/cross/arm-unknown-eabi/lib/ -isystem
/home/joty/projects/gccsdk/riscos7/cross/arm-unknown-eabi/include -isystem
/home/joty/projects/gccsdk/riscos7/cross/arm-unknown-eabi/sys-include
-I/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libstdc++-v3/include/arm-unknown-eabi
-I/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/builddir/cross-gcc/arm-unknown-eabi/libstdc++-v3/include
-I/home/joty/projects/gccsdk/gccsdk_svn7/gcc4/srcdir/gcc/libstdc++-v3/libsupc++
-fno-implicit-templates -Wall -Wextra -Wwrite-strings -Wcast-qual -Werror
-fdiagnostics-show-location=once -ffunction-sections -fdata-sections -g -O2 -c
ctype_members.cc -o ctype_members.o
ctype_members.cc: In member function 'virtual char
std::ctype<wchar_t>::do_narrow(wchar_t, char) const':
ctype_members.cc:206:17: error: comparison of unsigned expression >= 0 is
always true [-Werror=type-limits]
ctype_members.cc: In member function 'virtual const wchar_t*
std::ctype<wchar_t>::do_narrow(const wchar_t*, const wchar_t*, char, char*)
const':
ctype_members.cc:220:17: error: comparison of unsigned expression >= 0 is
always true [-Werror=type-limits]
cc1plus: all warnings being treated as errors
--8<--

Removing --enable-maintainer-mode is of course a workaround but I expect that
with a --disable-werror this should not result in -Werror being used at all.