-AC_CACHE_CHECK([whether preprocessor supports -Wunused-macros],
- [nmh_cv_has_unusedmacros],
- [nmh_saved_cppflags="$CPPFLAGS"
- CPPFLAGS="$CPPFLAGS -Wunused-macros -Wno-unused-macros"
- AC_TRY_COMPILE([],[],nmh_cv_has_unusedmacros=yes,nmh_cv_has_unusedmacros=no)
- CPPFLAGS="$nmh_saved_cppflags"])
-
-if test "$nmh_cv_has_unusedmacros" = 'yes'; then
- test -z "$CPPFLAGS" && CPPFLAGS=-Wunused-macros \
- || CPPFLAGS="$CPPFLAGS -Wunused-macros"
- DISABLE_UNUSED_MACROS_WARNING=-Wno-unused-macros
-fi
-AC_SUBST(DISABLE_UNUSED_MACROS_WARNING)dnl
-
-AC_CACHE_CHECK([whether compiler supports -Wno-sign-compare],
- [nmh_cv_has_nosigncompare],
- [nmh_saved_cppflags="$CPPFLAGS"
- CPPFLAGS="$CPPFLAGS -Wno-sign-compare"
- AC_TRY_COMPILE([],[],nmh_cv_has_nosigncompare=yes,
- nmh_cv_has_nosigncompare=no)
- CPPFLAGS="$nmh_saved_cppflags"])
-
-if test "$nmh_cv_has_nosigncompare" = 'yes'; then
- DISABLE_SIGN_COMPARE_WARNING=-Wno-sign-compare
-fi
-AC_SUBST(DISABLE_SIGN_COMPARE_WARNING)dnl
-
-AC_CACHE_CHECK([whether compiler supports -Wextra], [nmh_cv_has_wextra],
-[nmh_saved_cflags="$CFLAGS"
- CFLAGS="$CFLAGS -Wextra -Wno-clobbered"
- AC_TRY_COMPILE([],[],nmh_cv_has_wextra=yes,nmh_cv_has_wextra=no)
- CFLAGS="$nmh_saved_cflags"])
-
-AC_CACHE_CHECK([whether compiler supports -Wno-pointer-sign], [nmh_cv_has_noptrsign],
-[nmh_saved_cflags="$CFLAGS"
- CFLAGS="$CFLAGS -Wno-pointer-sign"
- AC_TRY_COMPILE([],[],nmh_cv_has_noptrsign=yes,nmh_cv_has_noptrsign=no)
- CFLAGS="$nmh_saved_cflags"])
-
-dnl if the user hasn't specified CFLAGS, then
-dnl if compiler is gcc, then
-dnl use -O2 and some warning flags
-dnl else use -O
-dnl We use -Wall and -Wextra if supported. If the compiler supports it we
-dnl also use -Wno-pointer-sign, because gcc 4 now produces a lot of new
-dnl warnings which are probably mostly spurious and which in any case we
-dnl don't want to deal with now.
-if test "$nmh_cv_has_noptrsign" = "yes"; then
- if test "$nmh_cv_has_wextra" = "yes"; then
- nmh_gcc_warnflags="-Wall -Wextra -Wno-clobbered -Wno-pointer-sign"
- else
- nmh_gcc_warnflags="-Wall -Wno-pointer-sign"
- fi
-else
- if test "$nmh_cv_has_wextra" = "yes"; then
- nmh_gcc_warnflags="-Wall -Wextra -Wno-clobbered"
- else
- nmh_gcc_warnflags="-Wall"
- fi
-fi
-