[tz] [PROPOSED 2/4] Simplify and fix new TZDIR setup

[Paul Eggert]

Put TZDIR’s definition in a new file tzdir.h instead of using
macros that do not always work with recursive ‘make’ invocations.
This follows up on the recent changes to make the Makefile more
POSIX-compatible.
* .gitignore: Ignore tzdir.h.
* Makefile (DTZDIR): Remove.  All uses removed.
(tzdir.h): New target rule.
(clean_misc): Remove tzdir.h.
(check_public): Pass TZDIR, not TZDIR.
(localtime.o, zic.o): Depend on tzdir.h.
* NEWS: Mention this.
* localtime.c, zic.c: Include tzdir.h.
* tzfile.h (TZDIR): Remove; now defined by tzdir.h.
---
 .gitignore  |  1 +
 Makefile    | 27 ++++++++++++++-------------
 NEWS        |  2 ++
 localtime.c |  1 +
 tzfile.h    |  4 ----
 zic.c       |  1 +
 6 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/.gitignore b/.gitignore
index cf3b8250..d50d176d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,6 +18,7 @@ ChangeLog
 check_*
 date
 leapseconds
+tzdir.h
 tzselect
 version
 version.h
diff --git a/Makefile b/Makefile
index edbc4d16..6e8e8fd9 100644
--- a/Makefile
+++ b/Makefile
@@ -549,10 +549,6 @@ RANLIB=		:
 ###############################################################################
 
 
-# $(CC) option to specify TZDIR, appropriately quoted.
-# It is separate from CFLAGS so that CFLAGS and TZDIR can be set independently.
-DTZDIR = -DTZDIR='"$(TZDIR)"'
-
 TZCOBJS=	zic.o
 TZDOBJS=	zdump.o localtime.o asctime.o strftime.o
 DATEOBJS=	date.o localtime.o strftime.o asctime.o
@@ -690,6 +686,13 @@ tzdata.zi:	$(DATAFORM).zi version zishrink.awk
 		    $(DATAFORM).zi >$@.out
 		mv $@.out $@
 
+tzdir.h:
+		printf '%s\n' >$@.out \
+		  '#ifndef TZDIR' \
+		  '# define TZDIR "$(TZDIR)" /* TZif directory */' \
+		  '#endif'
+		mv $@.out $@
+
 version.h:	version
 		VERSION=`cat version` && printf '%s\n' \
 		  'static char const PKGVERSION[]="($(PACKAGE)) ";' \
@@ -699,10 +702,10 @@ version.h:	version
 		mv $@.out $@
 
 zdump:		$(TZDOBJS)
-		$(CC) -o $@ $(DTZDIR) $(CFLAGS) $(LDFLAGS) $(TZDOBJS) $(LDLIBS)
+		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZDOBJS) $(LDLIBS)
 
 zic:		$(TZCOBJS)
-		$(CC) -o $@ $(DTZDIR) $(CFLAGS) $(LDFLAGS) $(TZCOBJS) $(LDLIBS)
+		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZCOBJS) $(LDLIBS)
 
 leapseconds:	$(LEAP_DEPS)
 		$(AWK) -v EXPIRES_LINE=$(EXPIRES_LINE) \
@@ -800,7 +803,7 @@ libtz.a:	$(LIBOBJS)
 		$(RANLIB) $@
 
 date:		$(DATEOBJS)
-		$(CC) -o $@ $(DTZDIR) $(CFLAGS) $(LDFLAGS) $(DATEOBJS) $(LDLIBS)
+		$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(DATEOBJS) $(LDLIBS)
 
 tzselect:	tzselect.ksh version
 		VERSION=`cat version` && sed \
@@ -947,7 +950,7 @@ clean_misc:
 		rm -fr check_*.dir typecheck_*.dir
 		rm -f *.o *.out $(TIME_T_ALTERNATIVES) \
 		  check_* core typecheck_* \
-		  date tzselect version.h zdump zic libtz.a
+		  date tzdir.h tzselect version.h zdump zic libtz.a
 clean:		clean_misc
 		rm -fr *.dir tzdb-*/
 		rm -f *.zi $(TZS_NEW)
@@ -1052,7 +1055,7 @@ check_public: $(VERSION_DEPS)
 		mkdir public.dir
 		ln $(VERSION_DEPS) public.dir
 		cd public.dir \
-		  && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' DTZDIR=$(DTZDIR) ALL
+		  && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' TZDIR='$(TZDIR)' ALL
 		for i in $(TDATA_TO_CHECK) public.dir/tzdata.zi \
 		    public.dir/vanguard.zi public.dir/main.zi \
 		    public.dir/rearguard.zi; \
@@ -1096,7 +1099,6 @@ $(TIME_T_ALTERNATIVES): $(VERSION_DEPS)
 		(cd $@.dir && \
 		  $(MAKE) TOPDIR="$$wd/$@.dir" \
 		    CFLAGS='$(CFLAGS) -Dtime_tz='"'$@'" \
-		    DTZDIR=$(DTZDIR) \
 		    REDO='$(REDO)' \
 			D=$$wd/$@.dir \
 		    TZS_YEAR="$$range" TZS_CUTOFF_FLAG="-t $$range" \
@@ -1260,7 +1262,6 @@ typecheck_long_long typecheck_unsigned: $(VERSION_DEPS)
 		  typecheck_cflags='' && \
 		  $(MAKE) \
 		    CFLAGS="$(TYPECHECK_CFLAGS) \"-Dtime_t=$$i\"" \
-		    DTZDIR=$(DTZDIR) \
 		    TOPDIR="`pwd`" \
 		    install
 		$@.dir/zdump -i -c 1970,1971 Europe/Rome
@@ -1272,10 +1273,10 @@ zonenames:	tzdata.zi
 asctime.o:	private.h tzfile.h
 date.o:		private.h
 difftime.o:	private.h
-localtime.o:	private.h tzfile.h
+localtime.o:	private.h tzfile.h tzdir.h
 strftime.o:	private.h tzfile.h
 zdump.o:	version.h
-zic.o:		private.h tzfile.h version.h
+zic.o:		private.h tzfile.h tzdir.h version.h
 
 .PHONY: ALL INSTALL all
 .PHONY: check check_mild check_time_t_alternatives
diff --git a/NEWS b/NEWS
index b7884c2d..0f033eca 100644
--- a/NEWS
+++ b/NEWS
@@ -46,6 +46,8 @@ Unreleased, experimental changes
      * It no longer uses its own 'cc' in place of CC.
      * It now uses ARFLAGS, with default specified by POSIX.
      * It does not use LFLAGS incompatibly with POSIX.
+    Due to the CC changes, TZDIR is now #defined in a file tzfile.h
+    built by 'make', not in a $(CC) -D option.
 
   Changes to commentary
 
diff --git a/localtime.c b/localtime.c
index f65a4295..319fd4ee 100644
--- a/localtime.c
+++ b/localtime.c
@@ -15,6 +15,7 @@
 #define LOCALTIME_IMPLEMENTATION
 #include "private.h"
 
+#include "tzdir.h"
 #include "tzfile.h"
 #include <fcntl.h>
 
diff --git a/tzfile.h b/tzfile.h
index 9cbdcff5..fcb7ab1d 100644
--- a/tzfile.h
+++ b/tzfile.h
@@ -21,10 +21,6 @@
 ** Information about time zone files.
 */
 
-#ifndef TZDIR
-# define TZDIR "/usr/share/zoneinfo" /* Time zone object file directory */
-#endif /* !defined TZDIR */
-
 #ifndef TZDEFAULT
 # define TZDEFAULT "/etc/localtime"
 #endif /* !defined TZDEFAULT */
diff --git a/zic.c b/zic.c
index cb473bdc..e10cb21b 100644
--- a/zic.c
+++ b/zic.c
@@ -14,6 +14,7 @@
 
 #include "version.h"
 #include "private.h"
+#include "tzdir.h"
 #include "tzfile.h"
 
 #include <fcntl.h>
-- 
2.40.1