Added checks for <sys/ucontext.h> as well.

git-svn-id: svn://svn.code.sf.net/p/dist/code/trunk/dist@154 2592e710-e01b-42a5-8df0-11608a6cc53d

1 files changed, 72 insertions, 3 deletions

diff --git a/mcon/U/i_ucontext.U b/mcon/U/i_ucontext.U
index 569e5fe..a819d9e 100644
--- a/mcon/U/i_ucontext.U
+++ b/mcon/U/i_ucontext.U
@@ -8,20 +8,89 @@
 ?RCS: that same Artistic Licence; a copy of which may be found at the root
 ?RCS: of the source tree for dist 4.0.
 ?RCS:
-?MAKE:i_ucontext: Inhdr
+?MAKE:i_ucontext i_sys_ucontext: Inhdr cat echo n c rm \
+	+cc +ccflags +ldflags
 ?MAKE:	-pick add $@ %<
 ?S:i_ucontext:
 ?S:	This variable conditionally defines the I_UCONTEXT symbol, and indicates
 ?S:	whether a C program may include <ucontext.h> to get ucontext_t.
 ?S:.
+?S:i_sys_ucontext:
+?S:	This variable conditionally defines the I_SYS_UCONTEXT symbol, and
+?S:	indicates whether a C program may include <sys/ucontext.h> to get
+?S:	ucontext_t.
+?S:.
 ?C:I_UCONTEXT:
 ?C:	This symbol, if defined, indicates to the C program that it should
-?C:	include <ucontext.h> to get at the user thread context.
+?C:	include <ucontext.h> to get at the user thread context.  A portable
+?C:	program must also check I_SYS_UCONTEXT for <sys/ucontex.h> inclusion,
+?C:	especially on OSX.
+?C:.
+?C:I_SYS_UCONTEXT:
+?C:	This symbol, if defined, indicates to the C program that it should
+?C:	include <sys/ucontext.h> to get at the user thread context.  A portable
+?C:	program must also check I_UCONTEXT for <ucontex.h> inclusion.
 ?C:.
 ?H:#$i_ucontext I_UCONTEXT		/**/
+?H:#$i_sys_ucontext I_SYS_UCONTEXT		/**/
 ?H:.
-?LINT:set i_ucontext
+?T:working
 : see if this is a ucontext.h system
 set ucontext.h i_ucontext
 eval $inhdr
 
+: see if this is a sys/ucontext.h system
+set sys/ucontext.h i_sys_ucontext
+eval $inhdr
+
+: when both ucontext.h and sys/ucontext.h are available, check which one works
+case "$i_ucontext$i_sys_ucontext" in
+"$define$define")
+	echo " "
+	$cat >try.c <<'EOC'
+#ifdef I_UCONTEXT
+#include <ucontext.h>
+#endif
+#ifdef I_SYS_UCONTEXT
+#include <sys/ucontext.h>
+#endif
+
+int main(void)
+{
+	static ucontext_t u;
+	return (int) sizeof(u) & 0xff;
+}
+EOC
+	$echo $n "Checking whether including <ucontext.h> alone works...$c" >&4
+	working=
+	if $cc $ccflags -DI_UCONTEXT -o try try.c $ldflags >/dev/null 2>&1; then
+		working="$define"
+	fi
+	case "$working" in
+	"$define")
+		echo " yes." >&4
+		i_sys_ucontext="$undef"
+		;;
+	*)
+		echo "no." >&4
+		echo " "
+		$echo $n "Checking whether including <sys/ucontext.h> works...$c" >&4
+		working=
+		if $cc $ccflags -DI_SYS_UCONTEXT \
+			-o try try.c $ldflags >/dev/null 2>&1
+		then
+			working="$define"
+		fi
+		case "$working" in
+		"$define")
+			echo " yes, ignoring <ucontext.h>." >&4
+			i_ucontext="$undef"
+			;;
+		*) echo " no, we'll include both then." >&4;;
+		esac
+		;;
+	esac
+	;;
+esac
+$rm -f try.*
+