Merge branch 'ng/depcomp-unify-o-obj-rules' into ng/master

* ng/depcomp-unify-o-obj-rules:
  [ng] depcomp: remove unused variable '$source' from the depcomp script
  [ng] depcomp: unify rules for '.o' and '.obj' objects
  [ng] depcomp: prefer make automatic variables over automake transforms

+ Extra non-trivial edits:

* t/libtool3.sh: Also look for the '.$(OBJEXT)' extension when grepping
the generated Makefile to ensure no explicit rules for the C compilation
has been emitted (only pattern rules should have been).
* t/subdir3.sh: Remove, since the changes done to it in the branch
'ng/depcomp-unify-o-obj-rules' have been obsoleted by the general
semantic changes done in the 'ng/subdir-objects' branch (where this
test had indeed been removed).
* t/subobj4.sh: Likewise.

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

diff --cc automake.in
Simple merge

diff --cc lib/am/depend2.am
Simple merge

diff --cc t/libtool3.sh
index 5ac3b1635247e392c926b7efeebaf8487d3ef531,2f18b150d54ce5c3b47267862aeaeeb995dee5d0..711581a9010a7ac73003671943ab3cc491b7ce31
--- 1/t/libtool3.sh
--- 2/t/libtool3.sh
+++ b/t/libtool3.sh
@@@ -76,8 -75,12 +76,8 @@@ $ACLOCA
  $AUTOCONF
  $AUTOMAKE --add-missing --copy
  
 -# We need explicit rules to build 1.$(OBJEXT) and a.lo.  Make sure
 -# Automake did not output additional rules for 1.lo and a.lo.
 -$FGREP '1.$(OBJEXT):' Makefile.in
 -$FGREP '1.lo:' Makefile.in && Exit 1
 -$FGREP 'a.$(OBJEXT):' Makefile.in && Exit 1
 -$FGREP 'a.lo:' Makefile.in
 +# We shouldn't need explicit rules.
- $EGREP '[^%]\.(o|obj|lo) *:' Makefile.in && Exit 1
++$EGREP '[^%]\.(o|obj|lo|\$\(OBJEXT\)) *:' Makefile.in && Exit 1
  
  ./configure
  

diff --cc t/silent-many-gcc.sh
index f6eabbed0b341e55eedc49873688c35af113fa3f,46d4e45710b84c0e577e3dde214b7ff0521b4431..eb00ceb2d2ed45d73fd21715f801decb565aab84
--- 1/t/silent-many-gcc.sh
--- 2/t/silent-many-gcc.sh
+++ b/t/silent-many-gcc.sh
@@@ -170,9 -196,9 +170,9 @@@ $FGREP am_cv_CC_dependencies_compiler_t
  $FGREP am_cv_CXX_dependencies_compiler_type configure
  # Ensure per-target rules are used, to ensure their coverage below.
  # (We do not do an exhaustive check, that wouldn't be practical).
- $FGREP 'bar-bar.o'  Makefile.in || Exit 99
 -$FGREP 'bar-bar.$(OBJEXT)' Makefile.in
 -$FGREP 'fo2-foo5.c' Makefile.in
 -$FGREP 'fo2-foo6.c' Makefile.in
++$FGREP 'bar-bar.$(OBJEXT)'  Makefile.in || Exit 99
 +$FGREP 'baz-foo5.c' Makefile.in || Exit 99
 +$FGREP 'baz-foo6.c' Makefile.in || Exit 99
  
  # Force gcc ("fast") depmode.
  depmodes="am_cv_CC_dependencies_compiler_type=gcc \

diff --cc t/silent-many-generic.sh
index a6b4a1e469c8acb48a1d83a7ae645ed429ac6be0,4e6c6f928643a8a67f7b8bb84afb6844d7a203ec..732079448ee9320575de309ce99ca66b5520c356
--- 1/t/silent-many-generic.sh
--- 2/t/silent-many-generic.sh
+++ b/t/silent-many-generic.sh
@@@ -197,9 -223,9 +197,9 @@@ $AUTOCON
  
  # Ensure per-target rules are used, to ensure their coverage below.
  # (We do not do an exhaustive check, that wouldn't be practical).
- $FGREP 'bar-bar.o'  Makefile.in || Exit 99
 -$FGREP 'bar-bar.$(OBJEXT)' Makefile.in
 -$FGREP 'fo2-foo5.c' Makefile.in
 -$FGREP 'fo2-foo6.c' Makefile.in
++$FGREP 'bar-bar.$(OBJEXT)'  Makefile.in || Exit 99
 +$FGREP 'baz-foo5.c' Makefile.in || Exit 99
 +$FGREP 'baz-foo6.c' Makefile.in || Exit 99
  
  # Force dependency tracking explicitly, so that slow dependency
  # extractors are not rejected.  Try also with dependency tracking