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$blocks_runtime"]
  11 )
  12
  13 #
  14 # Detect compiler support for Blocks; perhaps someday -fblocks won't be
  15 # required, in which case we'll need to change this.
  16 #
  17 AC_CACHE_CHECK([for C Blocks support], [dispatch_cv_cblocks], [
  18   saveCFLAGS="$CFLAGS"
  19   CFLAGS="$CFLAGS -fblocks"
  20   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[(void)^{int i; i = 0; }();])], [
  21     CFLAGS="$saveCFLAGS"
  22     dispatch_cv_cblocks="-fblocks"
  23   ], [
  24     CFLAGS="$saveCFLAGS"
  25     dispatch_cv_cblocks="no"
  26   ])
  27 ])
  28
  29 AS_IF([test "x$dispatch_cv_cblocks" != "xno"], [
  30     CBLOCKS_FLAGS="$dispatch_cv_cblocks"
  31
  32     #
  33     # It may be necessary to directly link the Blocks runtime on some
  34     # systems, so give it a try if we can't link a C program that uses
  35     # Blocks.  We will want to remove this at somepoint, as really -fblocks
  36     # should force that linkage already.
  37     #
  38     saveCFLAGS="$CFLAGS"
  39     CFLAGS="$CFLAGS -fblocks -O0"
  40     AC_MSG_CHECKING([whether additional libraries are required for the Blocks runtime])
  41     AC_TRY_LINK([], [
  42         ^{ int j; j=0; }();
  43     ], [
  44         AC_MSG_RESULT([no]);
  45     ], [
  46       saveLIBS="$LIBS"
  47       LIBS="$LIBS -lBlocksRuntime"
  48       AC_TRY_LINK([], [
  49         ^{ int k; k=0; }();
  50       ], [
  51         AC_MSG_RESULT([-lBlocksRuntime])
  52       ], [
  53         AC_MSG_ERROR([can't find Blocks runtime])
  54       ])
  55     ])
  56     CFLAGS="$saveCFLAGS"
  57     have_cblocks=true
  58 ], [
  59     CBLOCKS_FLAGS=""
  60     have_cblocks=false
  61 ])
  62 AM_CONDITIONAL(HAVE_CBLOCKS, $have_cblocks)
  63 AC_SUBST([CBLOCKS_FLAGS])
  64
  65 #
  66 # Because a different C++ compiler may be specified than C compiler, we have
  67 # to do it again for C++.
  68 #
  69 AC_LANG_PUSH([C++])
  70 AC_CACHE_CHECK([for C++ Blocks support], [dispatch_cv_cxxblocks], [
  71   saveCXXFLAGS="$CXXFLAGS"
  72   CXXFLAGS="$CXXFLAGS -fblocks"
  73   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[(void)^{int i; i = 0; }();])], [
  74     CXXFLAGS="$saveCXXFLAGS"
  75     dispatch_cv_cxxblocks="-fblocks"
  76   ], [
  77     CXXFLAGS="$saveCXXFLAGS"
  78     dispatch_cv_cxxblocks="no"
  79   ])
  80 ])
  81
  82 AS_IF([test "x$dispatch_cv_cxxblocks" != "xno"], [
  83     CXXBLOCKS_FLAGS="$dispatch_cv_cxxblocks"
  84
  85     saveCXXFLAGS="$CXXFLAGS"
  86     CXXFLAGS="$CXXFLAGS -fblocks -O0"
  87     AC_MSG_CHECKING([whether additional libraries are required for the Blocks runtime])
  88     AC_TRY_LINK([], [
  89         ^{ int j; j=0; }();
  90     ], [
  91         AC_MSG_RESULT([no]);
  92     ], [
  93       saveLIBS="$LIBS"
  94       LIBS="$LIBS -lBlocksRuntime"
  95       AC_TRY_LINK([], [
  96         ^{ int k; k=0; }();
  97       ], [
  98         AC_MSG_RESULT([-lBlocksRuntime])
  99       ], [
 100         AC_MSG_ERROR([can't find Blocks runtime])
 101       ])
 102     ])
 103     CXXFLAGS="$saveCXXFLAGS"
 104     have_cxxblocks=true
 105 ], [
 106     CXXBLOCKS_FLAGS=""
 107     have_cxxblocks=false
 108 ])
 109 AC_LANG_POP([C++])
 110 AM_CONDITIONAL(HAVE_CXXBLOCKS, $have_cxxblocks)
 111 AC_SUBST([CXXBLOCKS_FLAGS])
 112 ])