m4/na-compiler-flags.m4

   1 dnl GNOME_COMPILE_WARNINGS
   2 dnl Turn on many useful compiler warnings
   3 dnl For now, only works on GCC
   4
   5 # serial 3 Fix to correctly handle provided default values
   6
   7 #
   8 # pwi 2009-05-15 shamelessly copied from gnome-compiler-flags.m4
   9 # two patch have been submitted (see gnome-common #582860)
  10 #
  11
  12 AC_DEFUN([NA_GNOME_COMPILE_WARNINGS],[
  13
  14         _ac_warning_def=m4_default([$1],[yes])
  15         _ac_compliant_def=m4_default(["$2"],[no])
  16
  17     dnl ******************************
  18     dnl More compiler warnings
  19     dnl ******************************
  20
  21     AC_ARG_ENABLE(compile-warnings,
  22                   AC_HELP_STRING([--enable-compile-warnings=@<:@no/minimum/yes/maximum/error@:>@],
  23                                  [Turn on compiler warnings]),,
  24                   [enable_compile_warnings="${_ac_warning_def}"])
  25
  26     warnCFLAGS=
  27     if test "x$GCC" != xyes; then
  28         enable_compile_warnings=no
  29     fi
  30
  31     warning_flags=
  32     realsave_CFLAGS="$CFLAGS"
  33
  34     case "$enable_compile_warnings" in
  35     no)
  36         warning_flags=
  37         ;;
  38     minimum)
  39         warning_flags="-Wall"
  40         ;;
  41     yes)
  42         warning_flags="-Wall -Wmissing-prototypes"
  43         ;;
  44     maximum|error)
  45         warning_flags="-Wall -Wmissing-prototypes -Wnested-externs -Wpointer-arith"
  46         CFLAGS="$warning_flags $CFLAGS"
  47         for option in -Wno-sign-compare; do
  48                 SAVE_CFLAGS="$CFLAGS"
  49                 CFLAGS="$CFLAGS $option"
  50                 AC_MSG_CHECKING([whether gcc understands $option])
  51                 AC_TRY_COMPILE([], [],
  52                         has_option=yes,
  53                         has_option=no,)
  54                 CFLAGS="$SAVE_CFLAGS"
  55                 AC_MSG_RESULT($has_option)
  56                 if test $has_option = yes; then
  57                   warning_flags="$warning_flags $option"
  58                 fi
  59                 unset has_option
  60                 unset SAVE_CFLAGS
  61         done
  62         unset option
  63         if test "$enable_compile_warnings" = "error" ; then
  64             warning_flags="$warning_flags -Werror"
  65         fi
  66         ;;
  67     *)
  68         AC_MSG_ERROR(Unknown argument '$enable_compile_warnings' to --enable-compile-warnings)
  69         ;;
  70     esac
  71     CFLAGS="$realsave_CFLAGS"
  72     AC_MSG_CHECKING(what warning flags to pass to the C compiler)
  73     AC_MSG_RESULT($warning_flags)
  74
  75     AC_ARG_ENABLE(iso-c,
  76                   AC_HELP_STRING([--enable-iso-c],
  77                                  [Try to warn if code is not ISO C ]),,
  78                   [enable_iso_c="${_ac_compliant_def}"])
  79
  80     AC_MSG_CHECKING(what language compliance flags to pass to the C compiler)
  81     complCFLAGS=
  82     if test "x$enable_iso_c" != "xno"; then
  83                 if test "x$GCC" = "xyes"; then
  84                         if test "x${_ac_compliant_def}" = "x"; then
  85                                 case " $CFLAGS " in
  86                                         *[\ \   ]-ansi[\ \      ]*) ;;
  87                                     *) complCFLAGS="$complCFLAGS -ansi" ;;
  88                                 esac
  89                                 case " $CFLAGS " in
  90                                     *[\ \       ]-pedantic[\ \  ]*) ;;
  91                                     *) complCFLAGS="$complCFLAGS -pedantic" ;;
  92                                 esac
  93                         else
  94                                 complCFLAGS="$complCFLAGS ${_ac_compliant_def}"
  95                         fi
  96                 fi
  97     fi
  98     AC_MSG_RESULT($complCFLAGS)
  99
 100     WARN_CFLAGS="$warning_flags $complCFLAGS"
 101     AC_SUBST(WARN_CFLAGS)
 102 ])
 103
 104 dnl For C++, do basically the same thing.
 105
 106 AC_DEFUN([GNOME_CXX_WARNINGS],[
 107   AC_ARG_ENABLE(cxx-warnings,
 108                 AC_HELP_STRING([--enable-cxx-warnings=@<:@no/minimum/yes@:>@]
 109                                [Turn on compiler warnings.]),,
 110                 [enable_cxx_warnings="m4_default([$1],[minimum])"])
 111
 112   AC_MSG_CHECKING(what warning flags to pass to the C++ compiler)
 113   warnCXXFLAGS=
 114   if test "x$GXX" != xyes; then
 115     enable_cxx_warnings=no
 116   fi
 117   if test "x$enable_cxx_warnings" != "xno"; then
 118     if test "x$GXX" = "xyes"; then
 119       case " $CXXFLAGS " in
 120       *[\ \     ]-Wall[\ \      ]*) ;;
 121       *) warnCXXFLAGS="-Wall -Wno-unused" ;;
 122       esac
 123
 124       ## -W is not all that useful.  And it cannot be controlled
 125       ## with individual -Wno-xxx flags, unlike -Wall
 126       if test "x$enable_cxx_warnings" = "xyes"; then
 127         warnCXXFLAGS="$warnCXXFLAGS -Wshadow -Woverloaded-virtual"
 128       fi
 129     fi
 130   fi
 131   AC_MSG_RESULT($warnCXXFLAGS)
 132
 133    AC_ARG_ENABLE(iso-cxx,
 134                  AC_HELP_STRING([--enable-iso-cxx],
 135                                 [Try to warn if code is not ISO C++ ]),,
 136                  [enable_iso_cxx=no])
 137
 138    AC_MSG_CHECKING(what language compliance flags to pass to the C++ compiler)
 139    complCXXFLAGS=
 140    if test "x$enable_iso_cxx" != "xno"; then
 141      if test "x$GXX" = "xyes"; then
 142       case " $CXXFLAGS " in
 143       *[\ \     ]-ansi[\ \      ]*) ;;
 144       *) complCXXFLAGS="$complCXXFLAGS -ansi" ;;
 145       esac
 146
 147       case " $CXXFLAGS " in
 148       *[\ \     ]-pedantic[\ \  ]*) ;;
 149       *) complCXXFLAGS="$complCXXFLAGS -pedantic" ;;
 150       esac
 151      fi
 152    fi
 153   AC_MSG_RESULT($complCXXFLAGS)
 154
 155   WARN_CXXFLAGS="$CXXFLAGS $warnCXXFLAGS $complCXXFLAGS"
 156   AC_SUBST(WARN_CXXFLAGS)
 157 ])
 158
 159 dnl Bug #637797
 160 dnl see also http://www.gentoo.org/proj/en/qa/asneeded.xml
 161 dnl the '-Wl,--as-needed' link option is forced in make distcheck
 162
 163 AC_DEFUN([NA_LINK_AS_NEEDED],[
 164         AC_ARG_ENABLE(
 165                 [as-needed],
 166                 AC_HELP_STRING(
 167                         [--enable-as-needed],
 168                         [Enable '-Wl,--as-needed' link option @<:@no@:>@]
 169                 ),
 170                 [enable_as_needed=$enableval],
 171                 [enable_as_needed=no])
 172
 173         AC_MSG_CHECKING([whether to only link with needed libraries])
 174         AC_MSG_RESULT([$enable_as_needed])
 175
 176         if test "x${enable_as_needed}" = "xyes"; then
 177                 AC_SUBST([AM_LDFLAGS],["${AM_LDFLAGS} -Wl,--as-needed"])
 178         fi
 179 ])