gentoo-overlay/net-dialup/openl2tp/files/openl2tp-1.8-parallelbuild.patch

--- openl2tp-1.8/Makefile.orig	2020-07-12 12:53:31.484055262 +0300
+++ openl2tp-1.8/Makefile	2020-07-12 12:56:45.783822669 +0300
@@ -197,7 +197,7 @@
 
 .PHONY:			$(SUBDIRS:%=subdir-%)
 
-$(SUBDIRS:%=subdir-%):	FORCE
+$(SUBDIRS:%=subdir-%):	FORCE generated-files
 			$(MAKE) -C $(@:subdir-%=%) $(MFLAGS) EXTRA_CFLAGS="$(CPPFLAGS)"
 
 ifeq ($(L2TP_FEATURE_LOCAL_CONF_FILE),y)
@@ -211,7 +211,7 @@
 %.h %.c: %.y
 			$(YACC) -d -o l2tp_config_parse.c $<
 
-l2tp_config_token.o:	l2tp_config_token.c
+l2tp_config_token.o:	l2tp_config_token.c l2tp_config_parse.h
 			$(CC) -I. -MMD -w $(CFLAGS.optimize) -c -DYY_NO_UNPUT $<
 
 l2tp_config_parse.o:	l2tp_config_parse.c l2tp_config_parse.h
@@ -265,13 +265,13 @@
 			@for d in $(SUBDIRS); do $(MAKE) -C $$d $(MFLAGS) $@; done
 			etags $(wildcard *.c) $(wildcard *.h)
 
-openl2tpd:		$(L2TPD_SRCS.o)
-			$(CC) $(LDFLAGS) -o $@ $^ $(LDFLAGS.l2tpd)
+openl2tpd:	generated-files $(SUBDIRS:%=subdir-%) 	$(L2TPD_SRCS.o)
+			$(CC) $(LDFLAGS) -o $@ $(L2TPD_SRCS.o) $(LDFLAGS.l2tpd)
 
-l2tpconfig:		$(L2TPCONFIG_SRCS.o)
-			$(CC) $(LDFLAGS) -o $@ $^ $(LDFLAGS.l2tpconfig)
+l2tpconfig:	openl2tpd	$(L2TPCONFIG_SRCS.o)
+			$(CC) $(LDFLAGS) -o $@ $(L2TPCONFIG_SRCS.o) $(LDFLAGS.l2tpconfig)
 
-%.o:	%.c
+%.o:	%.c generated-files
 			$(CC) -c $(CFLAGS) $< -o $@
 
 l2tp_options.h:	FORCE