compile: rewrite AC_PROG_CC with AM_PROG_CC_C_O contents

This is a much simpler rewrite than the one we attempted in the past,
and that was later removed by commit 'v1.13.1d-137-g32eb770' of
2013-05-11 (compile: avoid AC_PROG_CC messy rewrite).

Not only this change simplifies the code a little, but has the welcome
collateral effect of making automatic dependency tracking work better
with compilers that doesn't grasp the '-c' and '-o' options together.
Issues in that setup have been caught by several failures in the target
'check-no-cc-c-o'.

Unfortunately, this change has less welcome collateral effects:

  1. AM_PROG_AR must now be called *after* AC_PROG_CC;

  2. Autoconf emits extra warnings when used with Automake-generated
     aclocal.m4.

These are unacceptable regressions for a release, but since we are
going to fix them soon enough in a follow-up patch (surely to be
applied before Automake 1.14 is released) we don't worry too much.

* m4/init.m4: Redefine AC_PROG_CC early, to automatically invoke
AM_PROG_CC_C_O as well.  Accordingly, drop now-unneeded "automagical"
AM_PROG_CC_C_O expansion at later time (which took place thanks to
a AC_CONFIG_COMMANDS_PRE call).
* m4/minuso.m4 (AM_PROG_CC_C_O): Ensure the expansion of the body
of this macro takes place with C as "current Autoconf language" (use
AC_LANG_PUSH/AC_LANG_POP).
* m4/ar-lib.m4 (AM_PROG_AR): Likewise.  Also, require this macro to
be expanded *after* AC_PROG_CC (so that any rewrite of $CC, if required,
has already taken place).
* t/add-missing.tap: Adjust to avoid spurious failures.
* t/aclocal-deps.sh: Likewise, by having AM_PROG_AR called *after*
AC_PROG_CC.
* t/subobj-clean-lt-pr10697.sh: Likewise.
* t/alloca.sh: Likewise.
* t/condlib.sh: Likewise.
* t/discover.sh: Likewise.
* t/objc-megademo.sh: Likewise.
* t/ccnoco.sh: Extend a little.
* t/ccnoco-deps.sh: New test.
* t/ccnoco-lib.sh: Likewise.
* t/ccnoco-lt.sh: Likewise.
* t/list-of-tests.mk: Add them.

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

1 files changed, 73 insertions, 0 deletions

diff --git a/t/ccnoco-lib.sh b/t/ccnoco-lib.sh
new file mode 100755
index 000000000..0e6a37510
--- /dev/null
+++ b/t/ccnoco-lib.sh
@@ -0,0 +1,73 @@
+#! /bin/sh
+# Copyright (C) 2001-2013 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test to make sure we can compile when the compiler doesn't
+# understand '-c -o'.
+
+required=gcc # For cc-no-c-o.
+. test-init.sh
+
+cat >> configure.ac << 'END'
+AC_PROG_CC
+$CC --version || exit 1
+$CC -v || exit 1
+AC_PROG_RANLIB
+AM_PROG_AR
+AC_OUTPUT
+END
+
+cat > Makefile.am << 'END'
+mylibsdir = $(libdir)/my-libs
+mylibs_LIBRARIES = libwish.a
+libwish_a_SOURCES = a.c
+# Make sure we need something strange.
+libwish_CFLAGS = -O0
+END
+
+cat > a.c << 'END'
+int wish_granted (void)
+{
+   return 0;
+}
+END
+
+# Make sure the compiler doesn't understand '-c -o'
+CC=$am_testaux_builddir/cc-no-c-o; export CC
+
+$ACLOCAL
+$AUTOCONF
+$AUTOMAKE --copy --add-missing
+
+for vpath in : false; do
+  if $vpath; then
+    srcdir=..
+    mkdir build
+    cd build
+  else
+    srcdir=.
+  fi
+  $srcdir/configure >stdout || { cat stdout; exit 1; }
+  cat stdout
+  $EGREP 'understands? -c and -o together.* no$' stdout
+  # No repeated checks please.
+  test $(grep -c ".*-c['\" ].*-o['\" ]" stdout) -eq 1
+  $MAKE
+  cd $srcdir
+done
+
+$MAKE distcheck
+
+: