m4/blocks.m4

   1 AC_DEFUN([DISPATCH_C_BLOCKS], [
   2 #
   3 # Allow configure to be passed a path to the directory where it should look
   4 # for the Blocks runtime library, if any.
   5 #
   6 AC_ARG_WITH([blocks-runtime],
   7   [AS_HELP_STRING([--with-blocks-runtime],
   8     [Specify path to the blocks runtime])],
   9   [blocks_runtime=${withval}
  10     LIBS="$LIBS -L$blocks_runtime"]
  11 )
  12
  13 #
  14 # Configure argument to enable/disable using an embedded blocks runtime
  15 #
  16 AC_ARG_ENABLE([embedded_blocks_runtime],
  17   [AS_HELP_STRING([--enable-embedded-blocks-runtime],
  18     [Embed blocks runtime in libdispatch [default=yes on Linux, default=no on all other platforms]])],,
  19   [case $target_os in
  20       linux*)
  21         enable_embedded_blocks_runtime=yes
  22             ;;
  23       *)
  24         enable_embedded_blocks_runtime=no
  25    esac]
  26 )
  27
  28 #
  29 # Detect compiler support for Blocks; perhaps someday -fblocks won't be
  30 # required, in which case we'll need to change this.
  31 #
  32 AC_CACHE_CHECK([for C Blocks support], [dispatch_cv_cblocks], [
  33   saveCFLAGS="$CFLAGS"
  34   CFLAGS="$CFLAGS -fblocks"
  35   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[(void)^{int i; i = 0; }();])], [
  36     CFLAGS="$saveCFLAGS"
  37     dispatch_cv_cblocks="-fblocks"
  38   ], [
  39     CFLAGS="$saveCFLAGS"
  40     dispatch_cv_cblocks="no"
  41   ])
  42 ])
  43
  44 AS_IF([test "x$dispatch_cv_cblocks" != "xno"], [
  45     CBLOCKS_FLAGS="$dispatch_cv_cblocks"
  46
  47         AS_IF([test "x$enable_embedded_blocks_runtime" != "xyes"], [
  48             #
  49             # It may be necessary to directly link the Blocks runtime on some
  50             # systems, so give it a try if we can't link a C program that uses
  51             # Blocks.  We will want to remove this at somepoint, as really -fblocks
  52             # should force that linkage already.
  53             #
  54             saveCFLAGS="$CFLAGS"
  55             CFLAGS="$CFLAGS -fblocks -O0"
  56             AC_MSG_CHECKING([whether additional libraries are required for the Blocks runtime])
  57             AC_TRY_LINK([], [
  58                 ^{ int j; j=0; }();
  59             ], [
  60                 AC_MSG_RESULT([no]);
  61             ], [
  62               saveLIBS="$LIBS"
  63               LIBS="$LIBS -lBlocksRuntime"
  64               AC_TRY_LINK([], [
  65                 ^{ int k; k=0; }();
  66               ], [
  67                 AC_MSG_RESULT([-lBlocksRuntime])
  68               ], [
  69                 AC_MSG_ERROR([can't find Blocks runtime])
  70               ])
  71             ])
  72         ])
  73     CFLAGS="$saveCFLAGS"
  74     have_cblocks=true
  75 ], [
  76     CBLOCKS_FLAGS=""
  77     have_cblocks=false
  78 ])
  79 AM_CONDITIONAL(HAVE_CBLOCKS, $have_cblocks)
  80 AC_SUBST([CBLOCKS_FLAGS])
  81 AM_CONDITIONAL([BUILD_OWN_BLOCKS_RUNTIME], [test "x$enable_embedded_blocks_runtime" = "xyes"])
  82
  83 #
  84 # Because a different C++ compiler may be specified than C compiler, we have
  85 # to do it again for C++.
  86 #
  87 AC_LANG_PUSH([C++])
  88 AC_CACHE_CHECK([for C++ Blocks support], [dispatch_cv_cxxblocks], [
  89   saveCXXFLAGS="$CXXFLAGS"
  90   CXXFLAGS="$CXXFLAGS -fblocks"
  91   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[(void)^{int i; i = 0; }();])], [
  92     CXXFLAGS="$saveCXXFLAGS"
  93     dispatch_cv_cxxblocks="-fblocks"
  94   ], [
  95     CXXFLAGS="$saveCXXFLAGS"
  96     dispatch_cv_cxxblocks="no"
  97   ])
  98 ])
  99
 100 AS_IF([test "x$dispatch_cv_cxxblocks" != "xno"], [
 101     CXXBLOCKS_FLAGS="$dispatch_cv_cxxblocks"
 102
 103         AS_IF([test "x$enable_embedded_blocks_runtime" != "xyes"], [
 104             saveCXXFLAGS="$CXXFLAGS"
 105             CXXFLAGS="$CXXFLAGS -fblocks -O0"
 106             AC_MSG_CHECKING([whether additional libraries are required for the Blocks runtime])
 107             AC_TRY_LINK([], [
 108                 ^{ int j; j=0; }();
 109             ], [
 110                 AC_MSG_RESULT([no]);
 111             ], [
 112               saveLIBS="$LIBS"
 113               LIBS="$LIBS -lBlocksRuntime"
 114               AC_TRY_LINK([], [
 115                 ^{ int k; k=0; }();
 116               ], [
 117                 AC_MSG_RESULT([-lBlocksRuntime])
 118               ], [
 119                 AC_MSG_ERROR([can't find Blocks runtime])
 120               ])
 121             ])
 122         ])
 123     CXXFLAGS="$saveCXXFLAGS"
 124     have_cxxblocks=true
 125 ], [
 126     CXXBLOCKS_FLAGS=""
 127     have_cxxblocks=false
 128 ])
 129 AC_LANG_POP([C++])
 130 AM_CONDITIONAL(HAVE_CXXBLOCKS, $have_cxxblocks)
 131 AC_SUBST([CXXBLOCKS_FLAGS])
 132 ])