AC_PREREQ([2.59])
AC_INIT([sandbox], [1.2.18.1], [sandbox@gentoo.org])
AM_INIT_AUTOMAKE
AC_CONFIG_HEADER([config.h])

dnl Checks for programs.
AC_PROG_CC
AC_ISC_POSIX
AC_PROG_INSTALL
AC_PROG_MAKE_SET
AC_PROG_AWK
AC_CHECK_PROGS([READELF], [readelf eu-readelf], [false])

AC_ENABLE_SHARED
AC_DISABLE_STATIC
dnl Next four lines is a hack to prevent libtool checking for CXX/F77
m4_undefine([AC_PROG_CXX])
m4_defun([AC_PROG_CXX],[])
m4_undefine([AC_PROG_F77])
m4_defun([AC_PROG_F77],[])
AC_PROG_LIBTOOL

AC_PREFIX_DEFAULT([/usr])

dnl Checks for libraries.
dnl Checks for header files.
AC_FUNC_ALLOCA
AC_HEADER_DIRENT
AC_HEADER_STDC
AC_HEADER_SYS_WAIT
AC_CHECK_HEADERS([ \
  fcntl.h limits.h memory.h stddef.h \
  stdlib.h string.h strings.h sys/file.h \
  sys/param.h sys/time.h unistd.h utime.h \
])

dnl Checks for typedefs, structures, and compiler characteristics.
AC_C_CONST
AC_TYPE_UID_T
AC_TYPE_MODE_T
AC_TYPE_SIZE_T
AC_CHECK_TYPES([ptrdiff_t])

dnl Checks for library functions.
AC_FUNC_CHOWN
AC_FUNC_FORK
AC_FUNC_LSTAT
AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK
AC_TYPE_SIGNAL
AC_FUNC_STAT
AC_CHECK_FUNCS([ \
  bzero ftruncate getcwd lchown memmove \
  memcpy memset mkdir pathconf realpath \
  rmdir setenv strcasecmp strchr strdup \
  strerror strndup strrchr strspn strstr \
  strtok_r \
])
dnl For librcutil
AC_CHECK_FUNCS([remove])

dnl Check if gcc provides va_copy or __va_copy (for librcutil)
AC_MSG_CHECKING([for va_copy])
AC_TRY_COMPILE([
    #include <stdarg.h>
  ], [
    va_list ap, aq;
    va_copy(ap, aq);
  ],
  [va_copy="va_copy"],
  [AC_TRY_COMPILE([
      #include <stdarg.h>
    ], [
      va_list ap, aq;
      __va_copy(ap, aq);
    ],
    [va_copy="__va_copy"],
    [AC_MSG_ERROR([Unable to determine name of va_copy macro])]
  )]
)
AC_MSG_RESULT([$va_copy])
if test x"$va_copy" != xva_copy ; then
  AC_DEFINE_UNQUOTED([va_copy], [$va_copy],
    [Define to name of va_copy macro proviced by gcc if its not `va_copy'.]
  )
fi

dnl Verify people aren't doing stupid shit
if test x"$enable_static" != xno ; then
  AC_MSG_ERROR([dont be a Kumba, building a libsandbox.a is stupid])
fi
if test x"$enable_shared" != xyes ; then
  AC_MSG_ERROR([dont be a Kumba, omitting a libsandbox.so is stupid])
fi
if echo $CFLAGS | $EGREP -e -static  >/dev/null 2>&1; then
  AC_MSG_ERROR([dont be a Kumba, using -static in CFLAGS is stupid])
fi
if echo $LDFLAGS | $EGREP -e -static  >/dev/null 2>&1; then
  AC_MSG_ERROR([dont be a Kumba, using -static in LDFLAGS is stupid])
fi

dnl Some libc's like those on bsd have dlopen() in libc, and not libdl
AC_CHECK_LIB([dl], [dlopen],
  [have_libdl="yes"],
  [have_libdl="no"]
)
if test x"$have_libdl" = xyes ; then
  LIBDL="-ldl"
  AC_SUBST([LIBDL])
  DL_LIB="dl"
else
  DL_LIB="c"
  AC_CHECK_LIB([c], [dlopen],
    [],
    [AC_MSG_ERROR([Unable to determine library providing dlopen])]
  )
fi

dnl uClibc doesn't currently provide dlvsym() so lets
dnl verify the toolchain supports it
AC_CHECK_LIB([$DL_LIB], [dlvsym],
  [AC_DEFINE([HAVE_DLVSYM], [1], [libdl supports dlvsym])],
  [AC_DEFINE([HAVE_DLVSYM], [0], [libdl does not support dlvsym])]
)

dnl when using libc5, (f)trucate's offset argument type is size_t with
dnl libc5, but it's off_t with libc6 (glibc2).
AC_MSG_CHECKING([truncate argument type])
TRUNC_ARG_TYPE=`echo '#include <unistd.h>' | $CC -E - | grep -q 'truncate.*size_t'`
if test "$TRUNC_ARG_TYPE"x != x ; then
  AC_MSG_RESULT([size_t])
  AC_DEFINE([TRUNCATE_T], [size_t], [truncate arg type])
else
  AC_MSG_RESULT([off_t])
  AC_DEFINE([TRUNCATE_T], [off_t], [truncate arg type])
fi

dnl Check if libc provides RTLD_NEXT
AC_MSG_CHECKING([for RTLD_NEXT])
AC_TRY_COMPILE([
    #define _GNU_SOURCE
    #include <dlfcn.h>
  ], [
    #if !defined(RTLD_NEXT)
    # error no RTLD_NEXT
    #endif
  ],
  [have_rtld_next="yes"],
  [have_rtld_next="no"]
)
AC_MSG_RESULT([$have_rtld_next])
if test x"$have_rtld_next" = xyes ; then
  AC_DEFINE([HAVE_RTLD_NEXT], [1], [Have RTLD_NEXT enabled libc])
fi

dnl we need to handle symbols differently based upon their version, 
dnl but we have to know which symbols the libc supports first
AC_MSG_CHECKING([libc path])
echo "int main(void) { return 0; }" > libctest.c
$CC $CFLAGS -Wl,-verbose -o libctest libctest.c &> libctest.log
cat libctest.log 1>&AS_MESSAGE_LOG_FD
LIBC_PATH=`$AWK '/attempt to open/ { if (($4 ~ /\/libc\.so/) && ($5 == "succeeded")) LIBC = $4; }; END {print LIBC}' libctest.log`
rm -f libctest*
if test x"$LIBC_PATH" = x || ! test -r "$LIBC_PATH" ; then
  AC_MSG_ERROR([Unable to determine LIBC PATH ($LIBC_PATH)])
fi
AC_MSG_RESULT([$LIBC_PATH])
AC_SUBST([LIBC_PATH])

dnl when intercepting libc calls, we have to know the name of the 
dnl libc to load and search with dl*() calls
AC_MSG_CHECKING([libc version])
dnl the sed script at the end here looks funny but it's ok ...
dnl they're m4 escape sequences for left and right brackets
echo "int main(void) { return 0; }" > libctest.c
$CC -Wall -o libctest libctest.c
LIBC_VERSION=`$READELF -d libctest | grep NEEDED.*libc\\.so | $AWK '{print $NF}' | sed -e 's:\@<:@::' -e 's:\@:>@::'`
rm -f libctest*
if test "$LIBC_VERSION"x = x ; then
  AC_MSG_ERROR([Unable to determine LIBC VERSION])
fi
AC_MSG_RESULT([$LIBC_VERSION])
AC_DEFINE_UNQUOTED([LIBC_VERSION], ["$LIBC_VERSION"], [Name of libc to hook into])

dnl check if we have 32bit or 64bit output
AC_ARG_ENABLE([multilib],
  AS_HELP_STRING([--enable-multilib],
    [enable building for multilib setups (default=disabled)]),
  [enable_multilib="$enableval"],
  [enable_multilib="no"]
)

if test x"$enable_multilib" != xno ; then
  AC_DEFINE([SB_HAVE_MULTILIB], [1], [Have multilib enabled system])
fi

AC_OUTPUT([
  Makefile
  scripts/Makefile
  etc/Makefile
  data/Makefile
  librcutil/Makefile
  src/Makefile
])