1 files changed, 57 insertions, 0 deletions
diff --git a/devel/bmake/files/mk/yacc.mk b/devel/bmake/files/mk/yacc.mk
new file mode 100644
index 00000000000..6872f4a4a7e
--- /dev/null
+++ b/devel/bmake/files/mk/yacc.mk
@@ -0,0 +1,57 @@
+# $Id: yacc.mk,v 1.1.1.1 2020/05/24 05:35:53 nia Exp $
+
+#
+#	@(#) Copyright (c) 1999-2011, Simon J. Gerraty
+#
+#	This file is provided in the hope that it will
+#	be of use.  There is absolutely NO WARRANTY.
+#	Permission to copy, redistribute or otherwise
+#	use this file is hereby granted provided that 
+#	the above copyright notice and this notice are
+#	left intact. 
+#      
+#	Please send copies of changes and bug-fixes to:
+#	sjg@crufty.net
+#
+
+# this file contains rules to DTRT when SRCS contains foo.y or foo.c
+# when only a foo.y exists.
+
+YACC?= yacc
+YFLAGS?= -v -t
+RM?= rm
+
+YACC.y?= ${YACC} ${YFLAGS}
+
+.if ${YACC.y:M-d} == "" || defined(NO_RENAME_Y_TAB_H)
+
+.y.c:
+	${YACC.y} ${.IMPSRC}
+	[ ! -s y.tab.c ] || mv y.tab.c ${.TARGET}
+	${RM} -f y.tab.[!h]
+
+.else
+
+# the touch of the .c is to ensure it is newer than .h (paranoia)
+.y.h:
+	${YACC.y} ${.IMPSRC}
+	[ ! -s y.tab.c ] || mv y.tab.c ${.TARGET:T:R}.c
+	[ ! -s y.tab.h ] || cmp -s y.tab.h ${.TARGET:T:R}.h \
+		|| mv y.tab.h ${.TARGET:T:R}.h
+	touch ${.TARGET:T:R}.c
+	${RM} -f y.tab.*
+
+# Normally the .y.h rule does the work - to avoid races.
+# If for any reason the .c is lost but the .h remains,
+# regenerate the .c
+.y.c:	${.TARGET:T:R}.h
+	[ -s ${.TARGET} ] || { \
+		${YACC.y} ${.IMPSRC} && \
+		{ [ ! -s y.tab.c ] || mv y.tab.c ${.TARGET}; \
+		${RM} y.tab.*; }; }
+.endif
+
+beforedepend:	${SRCS:T:M*.y:S/.y/.c/g}
+
+CLEANFILES+= ${SRCS:T:M*.y:S/.y/.[ch]/g}
+CLEANFILES+= y.tab.[ch]