configure.ac, */Makefile.am, CHANGES, README.md: converge to portable…

… make syntax (do not require fiddling with GNU make envvars on non-Linux builds)

Signed-off-by: Jim Klimov <jimklimov@gmail.com>

CHANGES

@@ -5,8 +5,9 @@ znapzend (0.21.3) unstable; urgency=medium
   * Extended handling of "org.znapzend:enabled=off" setting for sub-trees: now if the same intermediate dataset declares "org.znapzend:recursive=on", the disablement of znapzend handling takes place for descendants as well (previously it had effect only exactly for datasets that set "org.znapzend:enabled=off" as a local ZFS property)
   * Fixed CI recipes and contents for spell-checker
   * Added rc-script and integration documentation for FreeBSD and similar platforms
+  * Converted configure.ac and numerous Makefile.am to avoid GNU Make syntax in favor of portability: tested with Solaris/illumos Sun make and with FreeBSD make
 
- -- Jim Klimov <jimklimov@gmail.com>  Tue, 9 Jan 2024 13:42:28 +0100
+ -- Jim Klimov <jimklimov@gmail.com>  Tue, 12 Mar 2024 13:42:28 +0100
 
 znapzend (0.21.2) unstable; urgency=medium
 

Makefile.am

@@ -8,7 +8,7 @@ SUFFIXES = .1 .man .pm
 SUBDIRS = lib thirdparty debian
 
 BIN = bin/@PACKAGE@ bin/znapzendzetup bin/znapzendztatz
-PM :=  $(shell find $(srcdir)/lib/ -name "*.pm")
+PM  = @PERL_MODULES@
 MAN = man/znapzend.1 man/znapzendzetup.1 man/znapzendztatz.1
 POD = doc/znapzend.pod doc/znapzendzetup.pod doc/znapzendztatz.pod
 
@@ -22,8 +22,8 @@ EXTRA_DIST = VERSION COPYRIGHT README.md LICENSE CHANGES AUTHORS cpanfile $(BIN)
 	t/zfs t/znapzendzetup.t t/zpool \
 	debian/znapzend.links.in
 
-YEAR := $(shell date +%Y)
-DATE := $(shell date +%Y-%m-%d)
+YEAR = @CONFIG_YEAR@
+DATE = @CONFIG_DATE@
 
 if ENABLE_SVCINSTALL
 

README.md

@@ -80,6 +80,11 @@ you want to get a custom-made copy of znapzend, you will need a compiler and
 stuff to build some of the prerequisite perl modules into binary libraries
 for the target OS and architecture. For run-time you will need just perl.
 
+For a long time znapzend build required a GNU Make implementation. While this
+is no longer strictly the case, and at least Sun Make (as of OpenIndiana) and
+BSD Make (as of FreeBSD) are also known to work, the instructions below still
+suggest it as optional (if system-provided tools fail, fall back to `gmake`).
+
 The Git checkout includes a pregenerated `configure` script. For a rebuild
 of a checkout from scratch you may also want to `./bootstrap.sh` and then
 would need the autoconf/automake stack.
@@ -100,9 +105,11 @@ apt-get install autoconf carton
 
 * On Solaris 10 you may need the C compiler from Solaris Studio and gnu-make
 since the installed perl version is probably very old and you would likely
-have to build some dependency modules. The GNU make is needed instead of Sun
-make due to syntax differences. Notably you should reference it if you would
-boot-strap the code workspace from scratch:
+have to build some dependency modules. The GNU make may be needed instead
+of Sun make due to syntax standard differences over the years. Notably you
+could have to reference it if you would boot-strap the code workspace from
+scratch (and use later to `gmake install` as suggested by the `configure`
+script):
 ```sh
 MAKE=gmake ./bootstrap.sh
 ```
@@ -116,7 +123,7 @@ prior to running `configure`, e.g.:
 PERL=/opt/perl-32/bin/perl5.32.1 ./configure
 ```
 
-* On OmniOS/SmartOS you will need perl and gnu-make packages.
+* On OmniOS/SmartOS you will need perl and optionally gnu-make packages.
 
 * On macOS, if you have not already installed the Xcode command line tools,
 you can get them from the command line (Terminal app) with:

configure.ac

@@ -26,6 +26,12 @@ AC_PATH_PROG(WGET, wget, no)
 AC_PATH_PROG(POD2MAN, pod2man, no)
 AC_PATH_PROG(RM, rm, no)
 
+AC_MSG_CHECKING([for CONFIG_YEAR and CONFIG_DATE])
+CONFIG_YEAR="`date +%Y`"
+CONFIG_DATE="`date +%Y-%m-%d`"
+AC_MSG_RESULT([got ${CONFIG_YEAR} and ${CONFIG_DATE} respectively])
+AC_SUBST(CONFIG_YEAR)
+AC_SUBST(CONFIG_DATE)
 
 AC_ARG_ENABLE([deb_build],
 AS_HELP_STRING([--enable-deb_build    Enable debian package build specifics]),
@@ -134,14 +140,15 @@ fi
 
 AC_PROG_GREP
 
+dnl We tried to make te Makefile.am syntax portable, but hiccups are possible
 AC_ARG_VAR(GMAKE,   [Path to local GNU Make binary])
 AC_PATH_PROGS(GMAKE, [gnumake gmake make])
 
 AC_MSG_CHECKING([for gnu make availability])
 if  ( $GMAKE --version 2> /dev/null | $GREP GNU  > /dev/null 2>&1 );  then
     AC_MSG_RESULT([$GMAKE is GNU make])
 else
-    AC_MSG_ERROR([GNU make not found. Try setting the GMAKE environment variable.])
+    AC_MSG_WARN([GNU make not found, build recipes might fail. Try setting the GMAKE environment variable.])
 fi
 
 AC_ARG_ENABLE(pkgonly,
@@ -160,6 +167,21 @@ AC_MSG_RESULT(way to expensive!)
 AC_ARG_VAR(PERL5LIB,   [Colon separated list of perl library directories])
 AC_SUBST(PERL5LIB)
 
+AC_MSG_CHECKING([for PERL_MODULES])
+PERL_MODULES="`find "${srcdir}/lib/" -name "*.pm" | sed "s,^${srcdir}/,"'$(top_srcdir)/', | tr '\n' ' '`"
+AC_MSG_RESULT([${PERL_MODULES}])
+AC_SUBST(PERL_MODULES)
+
+AC_MSG_CHECKING([for PERL_CONFIG_VERSION])
+PERL_CONFIG_VERSION="`${PERL} -MConfig -e 'my $v = $Config{version}; $v =~ s/\.\d+$//; print $v;'`"
+AC_MSG_RESULT([${PERL_CONFIG_VERSION}])
+AC_SUBST(PERL_CONFIG_VERSION)
+
+AC_MSG_CHECKING([for PERL_THIRDPARTY_DIST cache])
+PERL_THIRDPARTY_DIST="`cd thirdparty && test -d cache && find cache -type f | tr '\n' ' '`"
+AS_IF([test x"${PERL_THIRDPARTY_DIST}" = x], [AC_MSG_RESULT([empty])], [AC_MSG_RESULT([populated])])
+AC_SUBST(PERL_THIRDPARTY_DIST)
+
 dnl Autotools default expansion of path settings results in further $variables
 dnl so for practical use in static configs this yarn has to be fully unrolled:
 dnl expand ${prefix} and write it out
@@ -271,9 +293,10 @@ Settings:
   URL_CAT = $URL_CAT
   DEB_BUILD = $deb_build
 
-The Makefiles use GNU make functionality.
-Continue installation with
+The Makefiles should be portable to the best extent of our testing,
+but their recipes should most certainly succeed with GNU make.
+It is recommended that now you continue installation with
 
-  $GMAKE install
+  ${GMAKE:-make} install
 
 NOTES

lib/Makefile.am

@@ -1,7 +1,7 @@
 # Author: Tobi Oetiker <tobi@oetiker.ch>
 # License: Public Domain
 
-PM :=  $(shell find $(srcdir) -name "*.pm")
+PM = @PERL_MODULES@
 
 datadir = $(libdir)
 nobase_data_DATA = $(PM)

thirdparty/Makefile.am

@@ -2,14 +2,16 @@
 
 AUTOMAKE_OPTIONS =  foreign
 
-THIRDPARTY_DIR := $(shell pwd)
+THIRDPARTY_DIR = $(abs_builddir)
 
-# THIRDPARTY_DIST := $(shell test -d cache && find cache -type f )
-CPANSNAPV := cpanfile-$(shell $(PERL) -MConfig -e 'my $$v = $$Config{version}; $$v =~ s/\.\d+$$//; print $$v').snapshot
+#GNU# THIRDPARTY_DIST :+ $(shell test -d cache && find cache -type f )
+# THIRDPARTY_DIST = @PERL_THIRDPARTY_DIST@
+CPANSNAPV = cpanfile-@PERL_CONFIG_VERSION@.snapshot
 
 
 #EXTRA_DIST = $(THIRDPARTY_DIST) $(wildcard bin/cpanm)
-EXTRA_DIST = bin/cpanm $(wildcard cpanfile*snapshot)
+#EXTRA_DIST = bin/cpanm $(wildcard cpanfile*snapshot)
+EXTRA_DIST = bin/cpanm cpanfile*snapshot
 
 all-local: touch