[tz] [PROPOSED 4/5] make Makefile more compatible with POSIX
Paul Eggert
eggert at cs.ucla.edu
Sun Nov 19 21:30:14 UTC 2023
This was initially motivated by a desire to have the Makefile be
friendlier to new builders, so that the Makefile does not use CC in
an unusual way, and so that builders can run commands like
‘make CC='gcc -std=gnu11'’ without messing up TZDIR.
While I was at it, I fixed other ways that the Makefile is
inconsistent with modern POSIX.
* Makefile (CFLAGS, LDFLAGS, AR, CC): Do not define. Instead,
rely on system-supplied defaults, which are specified by POSIX.
(SHELL): Do not define or use, as POSIX prohibits that.
(cc): Remove. All uses changed to use CC, which is where
POSIX expects the C compiler to be.
(DTZDIR): New macro, so that TZDIR is easily specified
regardless of CC or CFLAGS.
(zdump, zic, tzdir, check_public, $(TIME_T_ALTERNATIVES))
(typecheck_long_long, typecheck_unsigned):
Use TZDIR and pass it along.
(libtz.a): Use ARFLAGS rather than open-coding the default.
* NEWS: Mention these changes.
---
Makefile | 74 ++++++++++++++++++++++++++++++++++++++------------------
NEWS | 8 ++++++
2 files changed, 59 insertions(+), 23 deletions(-)
diff --git a/Makefile b/Makefile
index 4ebac475..722abfa3 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,20 @@
# Request POSIX conformance; this must be the first non-comment line.
.POSIX:
+# To affect how this Makefile works, you can run a shell script like this:
+#
+# #!/bin/sh
+# make CC='gcc -std=gnu11' "$@"
+#
+# This example script is appropriate for a pre-2017 GNU/Linux system
+# where a non-default setting is needed to support this package's use of C99.
+#
+# Alternatively, you can simply edit this Makefile to tailor the following
+# macro definitions.
+
+###############################################################################
+# Start of macros that one plausibly might want to tailor.
+
# Package name for the code distribution.
PACKAGE= tzcode
@@ -192,8 +206,9 @@ UTF8_LOCALE= en_US.utf8
# On some hosts, this should have -lintl unless CFLAGS has -DHAVE_GETTEXT=0.
LDLIBS=
-# Add the following to the end of the "CFLAGS=" line as needed to override
-# defaults specified in the source code. "-DFOO" is equivalent to "-DFOO=1".
+# Add the following to an uncommented "CFLAGS=" line as needed
+# to override defaults specified in the source code or by the system.
+# "-DFOO" is equivalent to "-DFOO=1".
# -DDEPRECATE_TWO_DIGIT_YEARS for optional runtime warnings about strftime
# formats that generate only the last two digits of year numbers
# -DEPOCH_LOCAL if the 'time' function returns local time not UT
@@ -273,6 +288,10 @@ LDLIBS=
# -DZIC_MAX_ABBR_LEN_WO_WARN=3
# (or some other number) to set the maximum time zone abbreviation length
# that zic will accept without a warning (the default is 6)
+# -g to generate symbolic debugging info
+# -Idir to include from directory 'dir'
+# -O0 to disable optimization; other -O options to enable more optimization
+# -Uname to remove any definition of the macro 'name'
# $(GCC_DEBUG_FLAGS) if you are using recent GCC and want lots of checking
#
# * Options marked "*" can be omitted if your compiler is C23 compatible.
@@ -393,13 +412,21 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
# 53 as a week number (rather than 52 or 53) for January days before
# January's first Monday when a "%V" format is used and January 1
# falls on a Friday, Saturday, or Sunday.
+#
+# POSIX says CFLAGS defaults to "-O 1".
+# Uncomment the following line and edit its contents as needed.
-CFLAGS=
+#CFLAGS= -O 1
-# Linker flags. Default to $(LFLAGS) for backwards compatibility
-# to release 2012h and earlier.
-LDFLAGS= $(LFLAGS)
+# The name of a POSIX-like library archiver, its flags, C compiler,
+# linker flags, and 'make' utility. Ordinarily the defaults suffice.
+# The commented-out values are the defaults specified by POSIX 202x/D3.
+#AR = ar
+#ARFLAGS = -rv
+#CC = c17
+#LDFLAGS =
+#MAKE = make
# For leap seconds, this Makefile uses LEAPSECONDS='-L leapseconds' in
# submake command lines. The default is no leap seconds.
@@ -508,17 +535,20 @@ GZIPFLAGS= -9n
DIFF_TZS= diff -u$$(! diff -u -F'^TZ=' - - <>/dev/null >&0 2>&1 \
|| echo ' -F^TZ=')
-###############################################################################
+# ':' on typical hosts; 'ranlib' on the ancient hosts that still need ranlib.
+RANLIB= :
-#MAKE= make
+# POSIX prohibits defining or using SHELL. However, csh users on systems
+# that use the user shell for Makefile commands may need to define SHELL.
+#SHELL= /bin/sh
-cc= cc
-CC= $(cc) -DTZDIR='"$(TZDIR)"'
+# End of macros that one plausibly might want to tailor.
+###############################################################################
-AR= ar
-# ':' on typical hosts; 'ranlib' on the ancient hosts that still need ranlib.
-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
@@ -589,11 +619,6 @@ VERSION_DEPS= \
ziguard.awk zishrink.awk \
zone.tab zone1970.tab
-# And for the benefit of csh users on systems that assume the user
-# shell should be used to handle commands in Makefiles. . .
-
-SHELL= /bin/sh
-
all: tzselect zic zdump libtz.a $(TABDATA) \
vanguard.zi main.zi rearguard.zi
@@ -671,10 +696,10 @@ version.h: version
mv $@.out $@
zdump: $(TZDOBJS)
- $(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZDOBJS) $(LDLIBS)
+ $(CC) -o $@ $(DTZDIR) $(CFLAGS) $(LDFLAGS) $(TZDOBJS) $(LDLIBS)
zic: $(TZCOBJS)
- $(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZCOBJS) $(LDLIBS)
+ $(CC) -o $@ $(DTZDIR) $(CFLAGS) $(LDFLAGS) $(TZCOBJS) $(LDLIBS)
leapseconds: $(LEAP_DEPS)
$(AWK) -v EXPIRES_LINE=$(EXPIRES_LINE) \
@@ -768,11 +793,11 @@ force_tzs: $(TZS_NEW)
libtz.a: $(LIBOBJS)
rm -f $@
- $(AR) -rc $@ $(LIBOBJS)
+ $(AR) $(ARFLAGS) $@ $(LIBOBJS)
$(RANLIB) $@
date: $(DATEOBJS)
- $(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(DATEOBJS) $(LDLIBS)
+ $(CC) -o $@ $(DTZDIR) $(CFLAGS) $(LDFLAGS) $(DATEOBJS) $(LDLIBS)
tzselect: tzselect.ksh version
VERSION=`cat version` && sed \
@@ -1023,7 +1048,8 @@ check_public: $(VERSION_DEPS)
rm -fr public.dir
mkdir public.dir
ln $(VERSION_DEPS) public.dir
- cd public.dir && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' ALL
+ cd public.dir \
+ && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' DTZDIR=$(DTZDIR) ALL
for i in $(TDATA_TO_CHECK) public.dir/tzdata.zi \
public.dir/vanguard.zi public.dir/main.zi \
public.dir/rearguard.zi; \
@@ -1067,6 +1093,7 @@ $(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 $$range" \
@@ -1230,6 +1257,7 @@ typecheck_long_long typecheck_unsigned: $(VERSION_DEPS)
typecheck_cflags='' && \
$(MAKE) \
CFLAGS="$(TYPECHECK_CFLAGS) \"-Dtime_t=$$i\"" \
+ DTZDIR=$(DTZDIR) \
TOPDIR="`pwd`" \
install
$@.dir/zdump -i -c 1970,1971 Europe/Rome
diff --git a/NEWS b/NEWS
index 82cd5da1..822f80f4 100644
--- a/NEWS
+++ b/NEWS
@@ -38,6 +38,14 @@ Unreleased, experimental changes
zic now works again on Linux 2.6.16 and 2.6.17 (2006).
(Problem reported by Rune Torgersen.)
+ Changes to build procedure
+
+ The Makefile is now more compatible with POSIX:
+ * It no longer defines AR, CC, CFLAGS, LDFLAGS, and SHELL.
+ * 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.
+
Release 2023c - 2023-03-28 12:42:14 -0700
--
2.40.1
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