grammar.y is now a built file.

It's built from grammar.y.in.  Do so in the Makefile, as well as in the
configure script, so if the grammar.y.in file is changed, the grammar.c
file gets changed.  Remove it on "make distclean".  Include grammar.y.in
in the distribution tarball.

Author: guyharris

Makefile.in

@@ -280,7 +280,7 @@ EXTRA_DIST = \
 	fad-getad.c \
 	fad-gifc.c \
 	fad-glifc.c \
-	grammar.y \
+	grammar.y.in \
 	install-sh \
 	lbl/os-aix4.h \
 	lbl/os-aix7.h \
@@ -510,7 +510,26 @@ scanner.h: scanner.c
 scanner.o: scanner.c grammar.h
 	$(CC) $(FULL_CFLAGS) -c scanner.c
 
-grammar.c: $(srcdir)/grammar.y
+#
+# Generate the grammar.y file.
+#
+# Some Makes, e.g. AIX Make and Solaris Make, can't handle "--file=$@.tmp:$<";
+# for example, the Solaris 9 make man page says
+#
+#	Because make assigns $< and $* as it would for implicit rules
+#	(according to the suffixes list and the directory contents),
+#	they may be unreliable when used within explicit target entries.
+#
+# and this is an explicit target entry.
+#
+# Therefore, instead of using $<, we explicitly put in $(srcdir)/libpcap.pc.in.
+#
+grammar.y: $(srcdir)/grammar.y.in ./config.status
+	@rm -f $@ $@.tmp
+	./config.status --file=$@.tmp:$(srcdir)/grammar.y.in
+	mv $@.tmp $@
+
+grammar.c: grammar.y
 	$(YACC) -p pcap_ -o grammar.c -d $<
 grammar.h: grammar.c
 ## Recover from the removal of $@
@@ -775,7 +794,7 @@ clean:
 	cd testprogs; $(MAKE) clean
 
 distclean: clean
-	rm -f Makefile config.cache config.log config.status \
+	rm -f Makefile grammar.y config.cache config.log config.status \
 	    config.h gnuc.h net os-proto.h libpcap.pc \
 	    pcap-config stamp-h stamp-h.in
 	rm -f $(MAN3PCAP_EXPAND:.in=) $(MANFILE:.in=) $(MANMISC:.in=)