acinclude.m4

   1 dnl Turn on the additional warnings last, so -Werror doesn't affect other tests.
   2
   3 AC_DEFUN([IDT_COMPILE_WARNINGS],[
   4    if test -f $srcdir/autogen.sh; then
   5         default_compile_warnings="error"
   6     else
   7         default_compile_warnings="no"
   8     fi
   9
  10     AC_ARG_WITH(compile-warnings,
  11                 AS_HELP_STRING([--with-compile-warnings=@<:@no/yes/error@:>@],
  12                                [Compiler warnings]),
  13                 [enable_compile_warnings="$withval"],
  14                 [enable_compile_warnings="$default_compile_warnings"])
  15
  16     warnCFLAGS=
  17     if test "x$GCC" != xyes; then
  18         enable_compile_warnings=no
  19     fi
  20
  21     warning_flags=
  22     realsave_CFLAGS="$CFLAGS"
  23
  24     case "$enable_compile_warnings" in
  25     no)
  26         warning_flags=
  27         ;;
  28     yes)
  29         warning_flags="-Wall -Wunused -Wmissing-prototypes -Wmissing-declarations"
  30         ;;
  31     maximum|error)
  32         warning_flags="-Wall -Wunused -Wchar-subscripts -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wpointer-arith"
  33         CFLAGS="$warning_flags $CFLAGS"
  34         for option in -Wno-sign-compare -Wno-pointer-sign; do
  35                 SAVE_CFLAGS="$CFLAGS"
  36                 CFLAGS="$CFLAGS $option"
  37                 AC_MSG_CHECKING([whether gcc understands $option])
  38                 AC_TRY_COMPILE([], [],
  39                         has_option=yes,
  40                         has_option=no,)
  41                 CFLAGS="$SAVE_CFLAGS"
  42                 AC_MSG_RESULT($has_option)
  43                 if test $has_option = yes; then
  44                   warning_flags="$warning_flags $option"
  45                 fi
  46                 unset has_option
  47                 unset SAVE_CFLAGS
  48         done
  49         unset option
  50         if test "$enable_compile_warnings" = "error" ; then
  51             warning_flags="$warning_flags -Werror"
  52         fi
  53         ;;
  54     *)
  55         AC_MSG_ERROR(Unknown argument '$enable_compile_warnings' to --enable-compile-warnings)
  56         ;;
  57     esac
  58     CFLAGS="$realsave_CFLAGS"
  59     AC_MSG_CHECKING(what warning flags to pass to the C compiler)
  60     AC_MSG_RESULT($warning_flags)
  61
  62     WARN_CFLAGS="$warning_flags"
  63     AC_SUBST(WARN_CFLAGS)
  64 ])
  65