dnl LX_C_IFDEF(MACRO-NAME, ACTION-IF-DEF, ACTION-IF-NOT-DEF)

dnl

dnl Check for the definition of macro MACRO-NAME using the current

dnl language's compiler.

dnl

dnl Orignally written by Ludovic Courtès <ludo@chbouib.org>

AC_DEFUN([LX_C_IFDEF],

  [AC_COMPILE_IFELSE([#ifndef $1

                      # error "Macro $1 is undefined!"

                      /* For some compilers (eg. SGI's CC), #error is not

                         enough...  */

                      please, do fail

                      #endif],

                     [$2], [$3])])

dnl LX_CXX_COMPILER_VENDOR(VENDOR-NAME, [NICKNAME])

dnl

dnl Set VENDOR-NAME to the lower-case name of the compiler vendor or

dnl `unknown' if the compiler's vendor is unknown. `compaq' means the

dnl CXX compiler as available on Tru64/OSF1/Digital Unix on Alpha

dnl machines. If NICKNAME is provided, set it to the compiler's usual

dnl name (eg. `g++', `cxx', `aCC', etc.).

dnl

dnl Based on work of Ludovic Courtès <ludo@chbouib.org>

AC_DEFUN([LX_CXX_COMPILER_VENDOR],

  [AC_REQUIRE([AC_PROG_CXX])

   AC_REQUIRE([AC_PROG_CXXCPP])

   AC_CACHE_CHECK([the C++ compiler vendor],

    [lx_cv_cxx_compiler_vendor],

    [AC_LANG_PUSH([C++])

     dnl Intel's icpc

     LX_C_IFDEF([__INTEL_COMPILER],

       [lx_cv_cxx_compiler_vendor=intel],

       [dnl GNU C++

        LX_C_IFDEF([__GNUG__],

         [lx_cv_cxx_compiler_vendor=gnu],

         [LX_C_IFDEF([__DECCXX],

           [lx_cv_cxx_compiler_vendor=compaq],

           [dnl HP's aCC

            LX_C_IFDEF([__HP_aCC],

             [lx_cv_cxx_compiler_vendor=hp],

             [dnl SGI CC

              LX_C_IFDEF([__sgi],

               [lx_cv_cxx_compiler_vendor=sgi],

               [dnl Note:  We are using the C compiler because VC++ doesn't

                dnl recognize `.cc'(which is used by `configure') as a C++ file

                dnl extension and requires `/TP' to be passed.

                AC_LANG_PUSH([C])

                LX_C_IFDEF([_MSC_VER],

                  [lx_cv_cxx_compiler_vendor=microsoft],

                  [lx_cv_cxx_compiler_vendor=unknown])

                AC_LANG_POP()])])])])])

     AC_LANG_POP()])

   $1="$lx_cv_cxx_compiler_vendor"

   dnl The compiler nickname

   ifelse([$2], , [],

     [case "$lx_cv_cxx_compiler_vendor" in

        intel)     $2=icpc;;

        gnu)       $2=g++;;

        compaq)    $2=cxx;;

        hp)        $2=aCC;;

        sgi)       $2=CC;;

        microsoft) $2=cl;;

        *)         $2=unknown;;

      esac])])

dnl Set some debugging and error reporting related compiler flags.

dnl uses lx_user_cxxflags

AC_DEFUN([LX_SET_CXXFLAGS],

  [AC_ARG_ENABLE([debug],

AS_HELP_STRING([--enable-debug@<:@=yes|no|full@:>@], [build with debugging support])

AS_HELP_STRING([--disable-debug], [build without debugging support @<:@default@:>@]),

     [], [enable_debug=no])

   LX_CXX_COMPILER_VENDOR([lx_cxx_compiler_vendor])

   AC_MSG_CHECKING([whether to build with debugging support])

   if test x"$enable_debug" != x"no"; then

     AC_DEFINE([DEBUG], [1], [Define for debugging support])

     lx_gnu_cxxflags="-ansi -pedantic -Wall -Wextra"

     lx_intel_cxxflags="-g"

     lx_unknown_cxxflags="-g"

     if test x"$enable_debug" = x"yes"; then

       lx_gnu_cxxflags="-g $lx_gnu_cxxflags"

       AC_MSG_RESULT([yes])

     else

       lx_gnu_cxxflags="-g3 --no-inline $lx_gnu_cxxflags"

       AC_MSG_RESULT([full])

     fi

     if test x"$lx_cxx_compiler_vendor" = x"gnu"; then

       CXXFLAGS="$lx_user_cxxflags $lx_gnu_cxxflags"

     elif test x"$lx_cxx_compiler_vendor" = x"intel"; then

       CXXFLAGS="$lx_user_cxxflags $lx_intel_cxxflags"

     else

       CXXFLAGS="$lx_user_cxxflags $lx_unknown_cxxflags"

     fi

   else

     AC_MSG_RESULT([no])

   fi

   AC_ARG_ENABLE([extra-warnings],

AS_HELP_STRING([--enable-extra-warnings], [enable extra warning messages])

AS_HELP_STRING([--disable-extra-warnings], [disable extra warning messages @<:@default@:>@]),

     [],[enable_extra_warnings=no])

   AC_MSG_CHECKING(whether to enable extra warning flags)

   if test x"$enable_extra_warnings" != x"no"; then

     if test x"$lx_cxx_compiler_vendor" = x"gnu"; then

       CXXFLAGS="$CXXFLAGS -ansi -pedantic -Wall -Wextra"

       CXXFLAGS="$CXXFLAGS -Wfloat-equal -Wundef -Wendif-labels -Wshadow"

       CXXFLAGS="$CXXFLAGS -Wpointer-arith -Wcast-qual -Wcast-align"

       CXXFLAGS="$CXXFLAGS -Wwrite-strings -Wconversion -Waggregate-return"

       CXXFLAGS="$CXXFLAGS -Wmissing-noreturn -Wmissing-format-attribute"

       CXXFLAGS="$CXXFLAGS -Wpacked -Wpadded -Wredundant-decls"

       CXXFLAGS="$CXXFLAGS -Wunreachable-code -Winline -Winvalid-pch"

       CXXFLAGS="$CXXFLAGS -Wlong-long -Wdisabled-optimization"

       CXXFLAGS="$CXXFLAGS -Wstack-protector"

     elif test x"$lx_cxx_compiler_vendor" = x"intel"; then

       CXXFLAGS="$CXXFLAGS -w2"

     fi

     AC_MSG_RESULT([yes])

   else

     AC_MSG_RESULT([no])

   fi])