e13cb306f0
Newer GCCs are triggering false-positive -Wmaybe-uninitialized warnings around code that uses gdb::optional: https://sourceware.org/ml/gdb-patches/2017-05/msg00118.html Using std::optional wouldn't help, it triggers the same warnings: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80635 Initializing the variables to quiet the warning would defeat the purpose of gdb::optional. Making the optional ctor memset its storage would be a pessimization. Wrapping gdb::optional's internals with "#pragma GCC diagnostic push/ignored/pop" doesn't work, we'd have to wrap uses of gdb::optional instead, which I think would get unwieldy and ugly as we start using gdb::optional more and more. The -Wmaybe-uninitialized warning is documented as producing false positives (unlike -Wuninialized), so until we find a better workaround, disable -Werror for this warning. You'll still see the warning when building gdb, but it won't cause a build failure. Tested by building with gcc 4.8.5, 5.3.1, and gcc trunk (20170428). gdb/ChangeLog: 2017-05-05 Pedro Alves <palves@redhat.com> * warning.m4 (build_warnings): Add -Wno-error=maybe-uninitialized. * configure: Regenerate. gdb/gdbserver/ChangeLog: 2017-05-05 Pedro Alves <palves@redhat.com> * configure: Regenerate.
121 lines
4.1 KiB
Plaintext
121 lines
4.1 KiB
Plaintext
dnl Autoconf configure script for GDB, the GNU debugger.
|
|
dnl Copyright (C) 1995-2017 Free Software Foundation, Inc.
|
|
dnl
|
|
dnl This file is part of GDB.
|
|
dnl
|
|
dnl This program is free software; you can redistribute it and/or modify
|
|
dnl it under the terms of the GNU General Public License as published by
|
|
dnl the Free Software Foundation; either version 3 of the License, or
|
|
dnl (at your option) any later version.
|
|
dnl
|
|
dnl This program is distributed in the hope that it will be useful,
|
|
dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
dnl GNU General Public License for more details.
|
|
dnl
|
|
dnl You should have received a copy of the GNU General Public License
|
|
dnl along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
AC_DEFUN([AM_GDB_WARNINGS],[
|
|
AC_ARG_ENABLE(werror,
|
|
AS_HELP_STRING([--enable-werror], [treat compile warnings as errors]),
|
|
[case "${enableval}" in
|
|
yes | y) ERROR_ON_WARNING="yes" ;;
|
|
no | n) ERROR_ON_WARNING="no" ;;
|
|
*) AC_MSG_ERROR(bad value ${enableval} for --enable-werror) ;;
|
|
esac])
|
|
|
|
# Enable -Werror by default when using gcc. Turn it off for releases.
|
|
if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" && $development; then
|
|
ERROR_ON_WARNING=yes
|
|
fi
|
|
|
|
WERROR_CFLAGS=""
|
|
if test "${ERROR_ON_WARNING}" = yes ; then
|
|
WERROR_CFLAGS="-Werror"
|
|
fi
|
|
|
|
# The options we'll try to enable.
|
|
build_warnings="-Wall -Wpointer-arith \
|
|
-Wno-unused -Wunused-value -Wunused-function \
|
|
-Wno-switch -Wno-char-subscripts \
|
|
-Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable \
|
|
-Wno-sign-compare -Wno-narrowing -Wno-error=maybe-uninitialized"
|
|
|
|
# Enable -Wno-format by default when using gcc on mingw since many
|
|
# GCC versions complain about %I64.
|
|
case "${host}" in
|
|
*-*-mingw32*) build_warnings="$build_warnings -Wno-format" ;;
|
|
*) build_warnings="$build_warnings -Wformat-nonliteral" ;;
|
|
esac
|
|
|
|
AC_ARG_ENABLE(build-warnings,
|
|
AS_HELP_STRING([--enable-build-warnings], [enable build-time compiler warnings if gcc is used]),
|
|
[case "${enableval}" in
|
|
yes) ;;
|
|
no) build_warnings="-w";;
|
|
,*) t=`echo "${enableval}" | sed -e "s/,/ /g"`
|
|
build_warnings="${build_warnings} ${t}";;
|
|
*,) t=`echo "${enableval}" | sed -e "s/,/ /g"`
|
|
build_warnings="${t} ${build_warnings}";;
|
|
*) build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
|
|
esac
|
|
if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
|
|
echo "Setting compiler warning flags = $build_warnings" 6>&1
|
|
fi])dnl
|
|
AC_ARG_ENABLE(gdb-build-warnings,
|
|
AS_HELP_STRING([--enable-gdb-build-warnings], [enable GDB specific build-time compiler warnings if gcc is used]),
|
|
[case "${enableval}" in
|
|
yes) ;;
|
|
no) build_warnings="-w";;
|
|
,*) t=`echo "${enableval}" | sed -e "s/,/ /g"`
|
|
build_warnings="${build_warnings} ${t}";;
|
|
*,) t=`echo "${enableval}" | sed -e "s/,/ /g"`
|
|
build_warnings="${t} ${build_warnings}";;
|
|
*) build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
|
|
esac
|
|
if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
|
|
echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
|
|
fi])dnl
|
|
|
|
# The set of warnings supported by a C++ compiler is not the same as
|
|
# of the C compiler.
|
|
AC_LANG_PUSH([C++])
|
|
|
|
WARN_CFLAGS=""
|
|
if test "x${build_warnings}" != x -a "x$GCC" = xyes
|
|
then
|
|
AC_MSG_CHECKING(compiler warning flags)
|
|
# Separate out the -Werror flag as some files just cannot be
|
|
# compiled with it enabled.
|
|
for w in ${build_warnings}; do
|
|
# GCC does not complain about -Wno-unknown-warning. Invert
|
|
# and test -Wunknown-warning instead.
|
|
case $w in
|
|
-Wno-*)
|
|
wtest=`echo $w | sed 's/-Wno-/-W/g'` ;;
|
|
*)
|
|
wtest=$w ;;
|
|
esac
|
|
|
|
case $w in
|
|
-Werr*) WERROR_CFLAGS=-Werror ;;
|
|
*)
|
|
# Check whether GCC accepts it.
|
|
saved_CFLAGS="$CFLAGS"
|
|
CFLAGS="$CFLAGS $wtest"
|
|
saved_CXXFLAGS="$CXXFLAGS"
|
|
CXXFLAGS="$CXXFLAGS $wtest"
|
|
AC_TRY_COMPILE([],[],WARN_CFLAGS="${WARN_CFLAGS} $w",)
|
|
CFLAGS="$saved_CFLAGS"
|
|
CXXFLAGS="$saved_CXXFLAGS"
|
|
esac
|
|
done
|
|
AC_MSG_RESULT(${WARN_CFLAGS} ${WERROR_CFLAGS})
|
|
fi
|
|
AC_SUBST(WARN_CFLAGS)
|
|
AC_SUBST(WERROR_CFLAGS)
|
|
|
|
AC_LANG_POP([C++])
|
|
])
|