[automake-commit] branch master updated: automake: make the ARFLAGS default 'cr' instead of 'cru'.

[Karl Berry]

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karl pushed a commit to branch master
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View the commit online:
https://git.savannah.gnu.org/gitweb/?p=automake.git;a=commitdiff;h=8cdbdda5aec652c356fe6dbba96810202176ae75

The following commit(s) were added to refs/heads/master by this push:
     new 8cdbdda5a automake: make the ARFLAGS default 'cr' instead of 'cru'.
8cdbdda5a is described below

commit 8cdbdda5aec652c356fe6dbba96810202176ae75
Author: Pavel Raiskup <praiskup@redhat.com>
AuthorDate: Tue Nov 21 08:30:00 2023 -0800

    automake: make the ARFLAGS default 'cr' instead of 'cru'.
    
    In some GNU/Linux distributions people started to compile 'ar'
    binary with --enable-deterministic-archives (binutils project).
    That, however, in combination with our previous long time working
    default AR_FLAGS=cru causes warnings on such installations:
    ar: `u' modifier ignored since `D' is the default (see `U')
    
    The 'u' option (at least with GNU binutils) did small optimization
    during repeated builds because it instructed 'ar' to not
    open/close unchanged *.o files and to rather read their contents
    from old archive file.  However, its removal should not cause a
    big performance hit for usual workflows.
    
    Distributions started using --enable-deterministic-archives
    knowing that it would disable the 'u', just to rather have a bit
    more deterministic builds.
    
    Also, to justify this change a bit more, keeping 'u' in ARFLAGS
    could only result in many per-project changes to override
    Automake's ARFLAGS default, just to silence such warnings.
    
    Fixes bug#20082.  Reported by Eric Blake.
    
    * bin/automake.in (handle_libraries): Use 'ARFLAGS=cr' by default.
    * doc/automake.texi (Building a library): Mention the changed
    ARFLAGS default.
    (@c LocalWords): Replace 'cru' with 'cr'.
    * m4/ar-lib.m4 (AM_PROG_AR): Cut out 'cru' string into separate
    ARFLAGS variable with new default 'cr'.
    * NEWS: Document.
---
 NEWS              | 5 ++++-
 bin/automake.in   | 2 +-
 doc/automake.texi | 4 ++--
 m4/ar-lib.m4      | 3 ++-
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/NEWS b/NEWS
index d9c8640ff..2a58785f3 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,9 @@ New in 1.17:
   - AM_PATH_PYTHON will also search for Python versions 3.10 - 3.15.  It has
     previously searched for 3.0 - 3.9. (bug#53530)
 
+  - The default value of $ARFLAGS is now "cr" instead of "cru", to
+    support deterministic builds. (bug#20082)
+
   - RANLIB may be overridden on a per-target basis.
 
   - AM_TEXI2FLAGS may be defined to pass extra flags to TEXI2DVI & TEXI2PDF.
@@ -69,7 +72,7 @@ New in 1.17:
   - Pass any options given to AM_PROG_LEX on to AC_PROG_LEX.
     (bug#65600 and bug#65730)
 
-* Obsolescent features:
+* Obsolescence:
 
   - py-compile no longer supports Python 0.x or 1.x versions.  Python 2.0,
     released in 2000, is currently the minimum required version.
diff --git a/bin/automake.in b/bin/automake.in
index edc0488b8..c0ffc1986 100644
--- a/bin/automake.in
+++ b/bin/automake.in
@@ -2674,7 +2674,7 @@ sub handle_libraries ()
     }
 
   define_variable ('AR', 'ar', INTERNAL);
-  define_variable ('ARFLAGS', 'cru', INTERNAL);
+  define_variable ('ARFLAGS', 'cr', INTERNAL);
   define_verbose_tagvar ('AR');
 
   foreach my $pair (@liblist)
diff --git a/doc/automake.texi b/doc/automake.texi
index 635bdd28c..af8dd836f 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -5181,7 +5181,7 @@ library and the list of objects, and finally by calling
 @code{RANLIB} (Automake will complain otherwise).  You should also
 call @code{AM_PROG_AR} to define @code{AR}, in order to support unusual
 archivers such as Microsoft lib.  @code{ARFLAGS} will default to
-@code{cru}; you can override this variable by setting it in your
+@code{cr}; you can override this variable by setting it in your
 @file{Makefile.am} or by @code{AC_SUBST}ing it from your
 @file{configure.ac}.  You can override the @code{AR} variable by
 defining a per-library @code{maude_AR} variable (@pxref{Program and
@@ -13625,7 +13625,7 @@ attach the @file{test-suite.log} file.
 @c  LocalWords:  Miller's installable includedir inc pkgdata EXEEXT libexec bsd
 @c  LocalWords:  pkglib libexecdir prog libcpio cpio's dlopen dlpreopen linux
 @c  LocalWords:  subsubsection OBJEXT esac lib LTLIBRARIES liblob LIBADD AR ar
-@c  LocalWords:  ARFLAGS cru ing maude libgettext lo LTLIBOBJS rpath SGI PRE yy
+@c  LocalWords:  ARFLAGS cr ing maude libgettext lo LTLIBOBJS rpath SGI PRE yy
 @c  LocalWords:  libmaude CCLD CXXFLAGS FFLAGS LFLAGS OBJCFLAGS RFLAGS DEFS cc
 @c  LocalWords:  OBJCXXFLAGS
 @c  LocalWords:  SHORTNAME vtable srcdir nostdinc basename yxx cxx ll lxx gdb
diff --git a/m4/ar-lib.m4 b/m4/ar-lib.m4
index f55b65019..e655b26f4 100644
--- a/m4/ar-lib.m4
+++ b/m4/ar-lib.m4
@@ -18,12 +18,13 @@ AC_REQUIRE([AM_AUX_DIR_EXPAND])dnl
 AC_REQUIRE_AUX_FILE([ar-lib])dnl
 AC_CHECK_TOOLS([AR], [ar lib "link -lib"], [false])
 : ${AR=ar}
+: ${ARFLAGS=cr}
 
 AC_CACHE_CHECK([the archiver ($AR) interface], [am_cv_ar_interface],
   [AC_LANG_PUSH([C])
    am_cv_ar_interface=ar
    AC_COMPILE_IFELSE([AC_LANG_SOURCE([[int some_variable = 0;]])],
-     [am_ar_try='$AR cru libconftest.a conftest.$ac_objext >&AS_MESSAGE_LOG_FD'
+     [am_ar_try='$AR $ARFLAGS libconftest.a conftest.$ac_objext 
>&AS_MESSAGE_LOG_FD'
       AC_TRY_EVAL([am_ar_try])
       if test "$ac_status" -eq 0; then
         am_cv_ar_interface=ar