compat: reinstate AM_CONFIG_HEADER and AM_PROG_CC_STDC

Make them give runtime warnings in the obsolete category, but apart
from that, make them behave as they did in Automake 1.12.x and earlier.

While removing those macros seemed quite harmless, because it didn't put
a real burden on the developers (requiring them just to do a quick edit
to configure.ac), it turned out to place an unsustainable burden (or at
least, a burden perceived as such) on distro packagers who use the latest
Automake to bootstrap existing packages.  Many of those packages, while
having likely updated to AC_CONFIG_HEADERS in their development version,
still used AM_CONFIG_HEADER in their existing released versions, and the
removal of this macro would have thus forced the Fedora packagers to
patch all of them.  References:

  <http://www.mail-archive.com/devel@lists.fedoraproject.org/msg52840.html>
  <http://www.spinics.net/lists/fedora-devel/msg175922.html>
  <http://blog.flameeyes.eu/2013/01/autotools-mythbuster-automake-pains>

In addition, the Fedora packagers have already decided to patch their
Automake 1.13.1 to reinstate the AM_CONFIG_HEADER and AM_PROG_CC_STDC
macros (plus other macros that I don't believe it's worth worrying about):

  <http://www.spinics.net/lists/fedora-devel/msg176098.html>
  <http://www.mail-archive.com/devel@lists.fedoraproject.org/msg53030.html>
  <http://pkgs.fedoraproject.org/cgit/automake.git/commit/?id=ffe6bc39>

So, rather than having one more incompatibility floating around, we
better mirror that change (or, actually, its relevant parts) in the
upstream.

* m4/obsolete-err.m4 (AM_CONFIG_HEADER, AM_PROG_CC_STDC): Revert to the
older semantics, plus a runtime warning in the 'obsolete' category.
* t/backcompat6.sh: Use AM_CONFIG_HEADER once again.
* t/am-config-header-no-more.sh: Rename ...
* t/am-config-header.sh: ... like this, and adjust.
* t/am-prog-cc-stdc-no-more.sh: Rename ...
* t/am-prog-cc-stdc.sh: ... like this, and adjust.
* t/list-of-tests.mk: Adjust.
* NEWS: Update.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/NEWS b/NEWS
index 88e5371..d49ed7b 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -64,6 +64,16 @@ New in 1.13.2:
     configure runtime (unfortunately, Autoconf does not yet support this
     scenario, so we cannot delegate the work to it).
 
+* Bugs fixed:
+
+  - The obsolete macros AM_CONFIG_HEADER or AM_PROG_CC_STDC work once
+    again, as they did in Automake 1.12.x (albeit printing runtime
+    warnings in the 'obsolete' category).  Removing them has turned
+    out to be a very bad idea, because it complicated distro packing
+    enormously.  Making them issue fatal warnings, as we did in
+    Automake 1.13, has turned out to be a similarly very bad idea,
+    for exactly the same reason.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 New in 1.13.1:

diff --git a/m4/obsolete-err.m4 b/m4/obsolete-err.m4
index d8119a4..f7ec1db 100644 (file)
--- a/m4/obsolete-err.m4
+++ b/m4/obsolete-err.m4
@@ -8,19 +8,21 @@
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-dnl TODO: Remove in Automake 1.15.
 AC_DEFUN([AM_CONFIG_HEADER],
-[AC_FATAL(['$0': this macro is obsolete.
-    You should use the 'AC][_CONFIG_HEADERS' macro instead.])])
+[AC_DIAGNOSE([obsolete],
+['$0': this macro is obsolete.
+You should use the 'AC][_CONFIG_HEADERS' macro instead.])dnl
+AC_CONFIG_HEADERS($@)])
 
-dnl TODO: Remove in Automake 1.15.
 AC_DEFUN([AM_PROG_CC_STDC],
-[AC_FATAL(['$0': this macro is obsolete.
-    You should simply use the 'AC][_PROG_CC' macro instead.
-    Also, your code should no longer depend upon 'am_cv_prog_cc_stdc',
-    but upon 'ac_cv_prog_cc_stdc'.])])
+[AC_PROG_CC
+am_cv_prog_cc_stdc=$ac_cv_prog_cc_stdc
+AC_DIAGNOSE([obsolete],
+['$0': this macro is obsolete.
+You should simply use the 'AC][_PROG_CC' macro instead.
+Also, your code should no longer depend upon 'am_cv_prog_cc_stdc',
+but upon 'ac_cv_prog_cc_stdc'.])])
 
-dnl TODO: Remove in Automake 1.14.
 AC_DEFUN([AM_C_PROTOTYPES],
          [AC_FATAL([automatic de-ANSI-fication support has been removed])])
 AU_DEFUN([fp_C_PROTOTYPES], [AM_C_PROTOTYPES])

diff --git a/t/am-config-header-no-more.sh b/t/am-config-header.sh
similarity index 55%
rename from t/am-config-header-no-more.sh
rename to t/am-config-header.sh
index 577ce05..49410e8 100755 (executable)
--- a/t/am-config-header-no-more.sh
+++ b/t/am-config-header.sh
@@ -14,30 +14,37 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Check that any attempt to use the obsolete macro AM_CONFIG_HEADER
-# elicits clear and explicit fatal errors.
+# Check that the obsolete macro AM_CONFIG_HEADER still works.
 
 . test-init.sh
 
-geterr ()
-{
-    "$@" -Wnone 2>stderr && { cat stderr >&2; exit 1; }
-    cat stderr >&2
-    grep "^configure\.ac:4:.*'AM_CONFIG_HEADER'.*obsolete" stderr
-    grep "'AC_CONFIG_HEADERS'.* instead" stderr
-}
+cat > Makefile.am <<'END'
+check-local:
+       test -f oldconf.h
+       test -f $(srcdir)/oldconf.in
+END
 
-$ACLOCAL
-mv aclocal.m4 aclocal.sav
+cat >> configure.ac <<'END'
+AM_CONFIG_HEADER([oldconf.h:oldconf.in])
+AC_OUTPUT
+END
 
-echo AM_CONFIG_HEADER >> configure.ac
+$ACLOCAL -Wno-obsolete
 
-geterr $ACLOCAL
-test ! -f aclocal.m4
+$AUTOCONF -Werror -Wall 2>stderr && { cat stderr >&2; exit 1; }
+cat stderr >&2
+grep "^configure\.ac:4:.*'AM_CONFIG_HEADER'.*obsolete" stderr
+grep "'AC_CONFIG_HEADERS'.* instead" stderr
 
-cat aclocal.sav "$am_automake_acdir"/obsolete-err.m4 > aclocal.m4
+$AUTOCONF -Werror -Wall -Wno-obsolete
 
-geterr $AUTOCONF
-geterr $AUTOMAKE
+$AUTOHEADER
+test -f oldconf.in
+
+$AUTOMAKE
+
+./configure
+$MAKE check-local
+$MAKE distcheck
 
 :

diff --git a/t/am-prog-cc-stdc-no-more.sh b/t/am-prog-cc-stdc.sh
similarity index 58%
rename from t/am-prog-cc-stdc-no-more.sh
rename to t/am-prog-cc-stdc.sh
index a43e2d1..e3e469c 100755 (executable)
--- a/t/am-prog-cc-stdc-no-more.sh
+++ b/t/am-prog-cc-stdc.sh
@@ -14,30 +14,31 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Check that any attempt to use the obsolete macro AM_CONFIG_HEADER
-# elicits clear and explicit fatal errors.
+# Check that the obsolete macro the obsolete macro AM_PROG_CC_STDC
+# still works.
 
+required=gcc
 . test-init.sh
 
-geterr ()
-{
-    "$@" -Wnone 2>stderr && { cat stderr >&2; exit 1; }
-    cat stderr >&2
-    grep "^configure\.ac:4:.*'AM_PROG_CC_STDC'.*obsolete" stderr
-    grep "'AC_PROG_CC'.* instead" stderr
-}
+cat >> configure.ac <<'END'
+AM_PROG_CC_STDC
+AC_OUTPUT
+END
 
-$ACLOCAL
-mv aclocal.m4 aclocal.sav
+echo bin_PROGRAMS = foo > Makefile.am
 
-echo AM_PROG_CC_STDC >> configure.ac
+$ACLOCAL
+$AUTOMAKE
 
-geterr $ACLOCAL
-test ! -f aclocal.m4
+$AUTOCONF -Wnone -Wobsolete -Werror 2>stderr && { cat stderr >&2; exit 1; }
+cat stderr >&2
+grep "^configure\.ac:4:.*'AM_PROG_CC_STDC'.*obsolete" stderr
+grep "'AC_PROG_CC'.* instead" stderr
 
-cat aclocal.sav "$am_automake_acdir"/obsolete-err.m4 > aclocal.m4
+echo 'int main (void) { return 0; }' > foo.c
 
-geterr $AUTOCONF
-geterr $AUTOMAKE
+./configure
+$MAKE
+$MAKE distcheck
 
 :

diff --git a/t/backcompat6.sh b/t/backcompat6.sh
index 75e5c4f..d84ea97 100755 (executable)
--- a/t/backcompat6.sh
+++ b/t/backcompat6.sh
@@ -38,7 +38,7 @@ AC_SUBST(two, $two)
 three=3
 AC_SUBST(three)
 AC_PROG_CC
-AC_CONFIG_HEADERS(config.h:config.hin)
+AM_CONFIG_HEADER(config.h:config.hin)
 AM_CONDITIONAL(CROSS_COMPILING, test "$cross_compiling" = yes)
 AC_OUTPUT(Makefile foo.got:foo1.in:foo2.in:foo3.in)
 END

diff --git a/t/list-of-tests.mk b/t/list-of-tests.mk
index 2a042ef..f1e3dca 100644 (file)
--- a/t/list-of-tests.mk
+++ b/t/list-of-tests.mk
@@ -130,8 +130,8 @@ t/amhello-cross-compile.sh \
 t/amhello-binpkg.sh \
 t/aminit-moreargs-deprecation.sh \
 t/amassign.sh \
-t/am-config-header-no-more.sh \
-t/am-prog-cc-stdc-no-more.sh \
+t/am-config-header.sh \
+t/am-prog-cc-stdc.sh \
 t/am-macro-not-found.sh \
 t/amopt.sh \
 t/amopts-location.sh \