Build tweaks related to tags files.

* lib-src/Makefile.in (tagsfiles): New variable.
(TAGS): Also depend on the source files.  Use our own etags program.
* lisp/Makefile.in (ETAGS): Add EXEEXT.
(lisptagsfiles1, lisptagsfiles2, lisptagsfiles3, lisptagsfiles4):
Remove.
(tagsfiles): New, replacing lisptagsfiles1 etc.
Remove irrelevant source files here rather than in the TAGS rule.
(${ETAGS}): New rule.
(TAGS): Also depend on the etags executable.
* lwlib/Makefile.in (EXEEXT): New, set by configure.
(ETAGS): Add EXEEXT.
(${ETAGS}): New rule.
(ctagsfiles): Use "wildcard".
(TAGS): Also depend on the etags executable.
* nt/Makefile.in (ETAGS, tagsfiles): New variables.
(${ETAGS}): New rule.
(TAGS): Fix dependencies.
* oldXMenu/Makefile.in (EXEEXT): New, set by configure.
(ETAGS): New variable, replacing $TAGS.  Use our own etags program.
Remove "-t" argument.
(${ETAGS}): New rule.
(tagsfiles): New variable.
(TAGS): New rule, with proper dependencies.
* src/Makefile.in (ETAGS): Add EXEEXT.  Add a build rule.
(ctagsfiles1, ctagsfiles2): Use "wildcard".
(ctagsfiles3): Remove.
(TAGS): Depend on etags.
(../lisp/TAGS, $(lwlibdir)/TAGS): Let the rules in the relevant
directories decide if updates are needed.

1 files changed, 11 insertions, 2 deletions

diff --git a/nt/Makefile.in b/nt/Makefile.in
index fc6887f163..86fca5f8e3 100644
--- a/nt/Makefile.in
+++ b/nt/Makefile.in
@@ -225,9 +225,18 @@ extraclean: maintainer-clean
 check:
 	@echo "We don't have any tests for the nt/ directory yet."
 
+ETAGS = ../lib-src/etags${EXEEXT}
+
+${ETAGS}: FORCE
+	${MAKE} -C ../lib-src $(notdir $@)
+
+tagsfiles= $(wildcard ${srcdir}/*.[ch])
+
+FORCE:
+.PHONY: tags FORCE
 tags: TAGS
-TAGS: ${EXE_FILES:${EXEEXT}=.c}
-	../lib-src/etags *.[ch]
+TAGS: ${ETAGS} ${tagsfiles}
+	${ETAGS} ${tagsfiles}
 
 ## Build the programs
 addpm${EXEEXT}: ${srcdir}/addpm.c ../src/epaths.h