subdir-objects: complain if it isn't enabled

Since the next major automake version will make the behaviour so far
only activated with the 'subdir-object' option mandatory, it's better
if we start warning users not using that option.

As suggested by Peter Johansson, we strive to avoid the warning when
it would be irrelevant, i.e., if all source files sit in "current"
directory.

See automake bug#13378.

* automake.in (handle_single_transform): Print the warning when
necessary.
* t/subobj.sh: Enhance.
* t/ax/depcomp.sh: Adjust.
* t/cscope.tap: Likewise.
* t/depcomp8a.sh: Likewise.
* t/depcomp8b.sh: Likewise.
* t/ext2.sh: Likewise.
* t/extra-portability.sh: Likewise.
* t/fort2.sh: Likewise.
* t/fort4.sh: Likewise.
* t/fort5.sh: Likewise.
* t/lex-line.sh: Likewise.
* t/libtool3.sh: Likewise.
* t/ltinstloc.sh: Likewise.
* t/ltlibsrc.sh: Likewise.
* t/ltorder.sh: Likewise.
* t/parallel-tests-suffix-prog.sh: Likewise.
* t/sourcefile-in-subdir.sh: Likewise.
* t/specflg9.sh: Likewise.
* t/subobj4.sh: Likewise.
* t/subobj7.sh: Likewise.
* t/subpkg-yacc.sh: Likewise.
* t/subpkg.sh: Likewise.
* t/suffix-custom-subobj-and-specflg.sh: Likewise.
* t/vala-libs.sh: Likewise.
* t/vala-non-recursive-setup.sh: Likewise.
* t/yacc-grepping2.sh: Likewise.
* t/yacc-line.sh: Likewise.

1 files changed, 54 insertions, 7 deletions

diff --git a/t/subobj.sh b/t/subobj.sh
index d16512abc..22ab2d30d 100755
--- a/t/subobj.sh
+++ b/t/subobj.sh
@@ -14,19 +14,63 @@
 # 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 of subdir objects with C.
+# Test of subdir objects with C and C++.
 
 . test-init.sh
 
-echo AC_PROG_CC >> configure.ac
+cat >> configure.ac <<'END'
+AC_PROG_CC
+AC_PROG_CXX
+AC_PROG_YACC
+AC_CONFIG_FILES([sub/Makefile])
+END
+
+$ACLOCAL
+: > ylwrap
 
 cat > Makefile.am << 'END'
-AUTOMAKE_OPTIONS = subdir-objects
+SUBDIRS = sub
 bin_PROGRAMS = wish
-wish_SOURCES = generic/a.c generic/b.c
+wish_SOURCES = generic/a.c
+wish_SOURCES += another/z.cxx
 END
 
-$ACLOCAL
+mkdir sub
+cat > sub/Makefile.am << 'END'
+dream_SOURCES = generic/b.c more/r.y
+bin_PROGRAMS = dream
+END
+
+AUTOMAKE_fails
+grep "^Makefile\.am:3:.*'generic/a\.c'.* in a subdirectory" stderr
+grep "^Makefile\.am:[34]:.*'another/z\.cxx'.* in a subdirectory" stderr
+grep "^sub/Makefile\.am:1:.*'generic/b\.c'.* in a subdirectory" stderr
+grep "option 'subdir-objects' is disabled" stderr
+# Verbose tips should be given, but not too many times.
+for msg in \
+  "possible forward-incompatibility" \
+  "advi[sc]e.* 'subdir-objects' option throughout" \
+  "unconditionally.* object file.* same subdirectory" \
+; do
+  test $(grep -c "$msg" stderr) -eq 1
+done
+
+# Guard against stupid typos.
+grep 'subdir-object([^s]|$)' stderr && exit 1
+
+$AUTOMAKE -Wno-unsupported
+
+echo AUTOMAKE_OPTIONS = subdir-objects >> Makefile.am
+AUTOMAKE_fails
+grep "^Makefile\.am" stderr && exit 1
+grep "^sub/Makefile\.am:.*'generic/b\.c'.* in a subdirectory" stderr
+grep "option 'subdir-objects' is disabled" stderr
+
+sed 's/^AM_INIT_AUTOMAKE/&([subdir-objects])/' configure.ac > configure.tmp
+mv -f configure.tmp configure.ac
+$ACLOCAL --force
+$AUTOMAKE
+
 rm -f compile
 $AUTOMAKE --add-missing 2>stderr || { cat stderr >&2; exit 1; }
 cat stderr >&2
@@ -35,9 +79,12 @@ grep '^configure\.ac:4:.*install.*compile' stderr
 test -f compile
 
 grep '^generic/a\.\$(OBJEXT):' Makefile.in
-grep '[^/]a\.\$(OBJEXT)' Makefile.in && exit 1
+grep '^generic/b\.\$(OBJEXT):' sub/Makefile.in
+grep '^another/z\.\$(OBJEXT):' Makefile.in
+$EGREP '(^|[^/])[abz]\.\$(OBJEXT)' Makefile.in sub/Makefile.in && exit 1
 
 # Opportunistically test for a different bug.
-grep '^generic/b\.\$(OBJEXT):.*dirstamp' Makefile.in
+grep '^another/z\.\$(OBJEXT):.*dirstamp' Makefile.in
+grep '^generic/b\.\$(OBJEXT):.*dirstamp' sub/Makefile.in
 
 :