--- a/lib/Makefile.am	Wed Jan 31 17:01:05 1996 +0000
+++ b/lib/Makefile.am	Thu Feb 01 03:43:49 1996 +0000
@@ -6,18 +6,36 @@
 
 INCLUDES = -I.. -I$(srcdir)
 
+fu_SOURCES = getdate.c posixtm.c argmatch.c backupfile.c basename.c \
+dirname.c error.c fileblocks.c filemode.c \
+full-write.c getopt.c getopt1.c getversion.c group-member.c idcache.c \
+isdir.c long-options.c makepath.c modechange.c obstack.c \
+safe-read.c save-cwd.c savedir.c stripslash.c userspec.c xgetcwd.c \
+xmalloc.c xstrdup.c xstrtol.c xstrtoul.c yesno.c
+
 fu_LIBADD = @LIBOBJS@ @ALLOCA@
 
 HEADERS = argmatch.h backupfile.h error.h fnmatch.h fsusage.h getopt.h \
 group-member.h long-options.h makepath.h modechange.h mountlist.h \
 obstack.h pathmax.h save-cwd.h xstrtol.h xstrtoul.h
 
-BUILT_SOURCES = posixtm.c getdate.c
 CONFIG_HEADER = ../config.h
+BUILT_SOURCES = getdate.c posixtm.c
+
+# Since this directory contains two parsers, we have to be careful to avoid
+# running two $(YACC)s during parallel makes.  See below.
+getdate.c: getdate.y
+	@echo expect 10 shift/reduce conflicts
+	$(YACC) $(srcdir)/getdate.y
+	mv y.tab.c getdate.c
 
-fu_SOURCES = getdate.c posixtm.c argmatch.c backupfile.c basename.c \
-dirname.c error.c fileblocks.c filemode.c \
-full-write.c getopt.c getopt1.c getversion.c group-member.c idcache.c \
-isdir.c long-options.c makepath.c modechange.c obstack.c \
-safe-read.c save-cwd.c savedir.c stripslash.c userspec.c xgetcwd.c \
-xmalloc.c xstrdup.c xstrtol.c xstrtoul.c yesno.c
+# Make the rename atomic, in case sed is interrupted and later rerun.
+# The artificial dependency on getdate.c keeps the two parsers from being
+# built in parallel.  Enforcing this little bit of sequentiality lets
+# everyone (even those without bison) still run mostly parallel builds.
+posixtm.c: posixtm.y getdate.c
+	$(YACC) $(srcdir)/posixtm.y
+	mv y.tab.c posixtm.tab.c
+	sed -e 's/yy/zz/g' posixtm.tab.c > tposixtm.c
+	mv tposixtm.c posixtm.c
+	rm -f posixtm.tab.c