#
# Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
#
# This code is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 2 only, as
# published by the Free Software Foundation.  Oracle designates this
# particular file as subject to the "Classpath" exception as provided
# by Oracle in the LICENSE file that accompanied this code.
#
# This code is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# version 2 for more details (a copy is included in the LICENSE file that
# accompanied this code).
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# 2 along with this work; if not, write to the Free Software Foundation,
# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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################################################################################
# Setup libffi (Foreign Function Interface)
################################################################################
AC_DEFUN_ONCE([LIB_SETUP_LIBFFI],
[
  AC_ARG_WITH(libffi, [AS_HELP_STRING([--with-libffi],
      [specify prefix directory for the libffi package
      (expecting the libraries under PATH/lib and the headers under PATH/include)])])
  AC_ARG_WITH(libffi-include, [AS_HELP_STRING([--with-libffi-include],
      [specify directory for the libffi include files])])
  AC_ARG_WITH(libffi-lib, [AS_HELP_STRING([--with-libffi-lib],
      [specify directory for the libffi library])])

  if test "x$NEEDS_LIB_FFI" = xfalse; then
    if test "x${with_libffi}" != x || test "x${with_libffi_include}" != x || test "x${with_libffi_lib}" != x; then
      AC_MSG_WARN([libffi not used, so --with-libffi is ignored])
    fi
    LIBFFI_CFLAGS=
    LIBFFI_LIBS=
  else
    LIBFFI_FOUND=no

    if test "x${with_libffi}" = xno || test "x${with_libffi_include}" = xno || test "x${with_libffi_lib}" = xno; then
      AC_MSG_ERROR([It is not possible to disable the use of libffi. Remove the --without-libffi option.])
    fi

    if test "x${with_libffi}" != x; then
      LIBFFI_LIBS="-L${with_libffi}/lib -lffi"
      LIBFFI_CFLAGS="-I${with_libffi}/include"
      LIBFFI_FOUND=yes
    fi
    if test "x${with_libffi_include}" != x; then
      LIBFFI_CFLAGS="-I${with_libffi_include}"
      LIBFFI_FOUND=yes
    fi
    if test "x${with_libffi_lib}" != x; then
      LIBFFI_LIBS="-L${with_libffi_lib} -lffi"
      LIBFFI_FOUND=yes
    fi
    # Do not try pkg-config if we have a sysroot set.
    if test "x$SYSROOT" = x; then
      if test "x$LIBFFI_FOUND" = xno; then
        # Figure out LIBFFI_CFLAGS and LIBFFI_LIBS
        PKG_CHECK_MODULES([LIBFFI], [libffi], [LIBFFI_FOUND=yes], [LIBFFI_FOUND=no])
      fi
    fi
    if test "x$LIBFFI_FOUND" = xno; then
      AC_CHECK_HEADERS([ffi.h],
          [
            LIBFFI_FOUND=yes
            LIBFFI_CFLAGS=
            LIBFFI_LIBS=-lffi
          ],
          [LIBFFI_FOUND=no]
      )
    fi
    if test "x$LIBFFI_FOUND" = xno; then
      HELP_MSG_MISSING_DEPENDENCY([ffi])
      AC_MSG_ERROR([Could not find libffi! $HELP_MSG])
    fi

    AC_MSG_CHECKING([if libffi works])
    AC_LANG_PUSH(C)
    OLD_CFLAGS="$CFLAGS"
    CFLAGS="$CFLAGS $LIBFFI_CFLAGS"
    OLD_LIBS="$LIBS"
    LIBS="$LIBS $LIBFFI_LIBS"
    AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <ffi.h>],
        [
          ffi_call(NULL, NULL, NULL, NULL);
          return 0;
        ])],
        [LIBFFI_WORKS=yes],
        [LIBFFI_WORKS=no]
    )
    CFLAGS="$OLD_CFLAGS"
    LIBS="$OLD_LIBS"
    AC_LANG_POP(C)
    AC_MSG_RESULT([$LIBFFI_WORKS])

    if test "x$LIBFFI_WORKS" = xno; then
      HELP_MSG_MISSING_DEPENDENCY([ffi])
      AC_MSG_ERROR([Found libffi but could not link and compile with it. $HELP_MSG])
    fi
  fi

  AC_SUBST(LIBFFI_CFLAGS)
  AC_SUBST(LIBFFI_LIBS)
])