AC_INIT([protobuf-c], [0.12])
AM_INIT_AUTOMAKE([1.9 foreign])
PACKAGE=protobuf-c
AC_PROG_CC
AC_PROG_CXX
AC_PROG_LIBTOOL
AC_PATH_PROG(PROTOC, protoc)
AC_CHECK_HEADERS(inttypes.h)
AC_CHECK_HEADERS(sys/poll.h)
AC_CHECK_HEADERS(sys/select.h)
AC_CHECK_HEADERS(alloca.h)
AC_CHECK_HEADERS(malloc.h)
AC_CHECK_HEADERS(winsock.h)

BUILD_PROTOC_C=1
AC_ARG_ENABLE(protoc, [  --disable-protoc    Suppress build of protoc_c],
              if test "x$enableval" = xno ; then
	        BUILD_PROTOC_C=0
              fi)
AM_CONDITIONAL(BUILD_PROTOC_C, test $BUILD_PROTOC_C = 1)

# --- Check for the protobuf library. ---
if test $BUILD_PROTOC_C = 1; then
  AC_LANG_PUSH([C++])
  AC_CHECK_HEADER(google/protobuf/stubs/common.h,,
		  [AC_MSG_ERROR([
  ERROR: protobuf headers are required.

  You must either install protobuf from google,
  or if you have it installed in a custom location
  you must add '-Iincludedir' to CXXFLAGS
  and '-Llibdir' to LDFLAGS.

  If you did not specify a prefix when installing
  protobuf, try 
    './configure CXXFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib'
  In some 64-bit environments, try LDFLAGS=-L/usr/local/lib64.
  ])])
  pbc_savelibs="$LIBS"
  LIBS="$LIBS -lprotoc -lprotobuf -lpthread"
  AC_TRY_LINK([#include <google/protobuf/compiler/command_line_interface.h>],
	      [google::protobuf::compiler::CommandLineInterface cli;],
	      [],
	      [AC_MSG_ERROR([
  ERROR:
  protobuf test program failed to link:
  perhaps you need to add -Llibdir to your LDFLAGS.])])
  LIBS="$pbc_savelibs"
  AC_LANG_POP()

  dnl We need $PROTOC around for the test code generation.
  dnl This is merely needed for c++ packed-data comparison.
  if test "x$PROTOC" = x; then
    echo "ERROR: missing google's protoc program; adjust \$PATH (or use --disable-protoc)" 1>&2
    exit 1
  fi
fi

dnl  ------ define IS_LITTLE_ENDIAN ------
# We try to use, where possible the headers <endian.h>, <mach/endian.h>,
# and <machine/endian.h>, in that order.  They must define the macros
# __LITTLE_ENDIAN and __BYTE_ORDER.  We structure the test so that if they 
# do NOT define __LITTLE_ENDIAN or __BYTE_ORDER then we will disable
# the little-endian optimizations, so the resulting code should be correct,
# but not as fast, if there's a broken endian.h somewhere.
#
# If none of those headers exist, we fallback on a runtime test.
# TODO: support --with-endianness=[little|big]
knows_endianness=0
AC_CHECK_HEADERS([endian.h], [has_endian_h=1; knows_endianness=1], [has_endian_h=0])
if test $knows_endianness = 1 ; then
  AC_TRY_COMPILE([#include <endian.h>], [
   switch (1) { case __LITTLE_ENDIAN: break;
		case __BYTE_ORDER: break; } ],
    [is_little_endian=0], [is_little_endian=1])
else

  # ------------------ try <mach/endian.h>  ------------------
  AC_CHECK_HEADERS([mach/endian.h], [has_mach_endian_h=1; knows_endianness=1], [has_mach_endian_h=0])
  if test $knows_endianness = 1 ; then
    AC_TRY_COMPILE([#include <mach/endian.h>],[
      switch (1) { case __LITTLE_ENDIAN: break;
		   case __BYTE_ORDER: break; }
			      ],
      [is_little_endian=0], [is_little_endian=1])
  fi
  # ------------------ try <machine/endian.h>  ------------------
  if test $knows_endianness = 0; then
    AC_CHECK_HEADERS([machine/endian.h], [has_machine_endian_h=1; knows_endianness=1], [has_machine_endian_h=0])
    if test $knows_endianness = 1 ; then
      AC_TRY_COMPILE([#include <machine/endian.h>],[
	switch (1) { case __LITTLE_ENDIAN: break;
		     case __BYTE_ORDER: break; }
				],
	[is_little_endian=0], [is_little_endian=1])
    fi
  fi
  if test $knows_endianness = 0; then
    AC_MSG_CHECKING([for little-endianness via runtime check])
    AC_RUN_IFELSE([#include <inttypes.h>
    int main() {
      uint32_t v = 0x01020304;
      return memcmp (&v, "\4\3\2\1", 4) == 0 ? 0 : 1;
    }
    ], [is_little_endian=1; result=yes], [is_little_endian=0; result=no])
    AC_MSG_RESULT($result)
  fi
fi

if test $is_little_endian = 1; then
  echo "Your system IS little-endian" 1>&2
else
  echo "Your system IS NOT little-endian" 1>&2
fi
AC_DEFINE_UNQUOTED(IS_LITTLE_ENDIAN, $is_little_endian)

AC_OUTPUT( Makefile src/Makefile src/test/Makefile pkgwriteinfo )