[PATCHv2 7/8] aclocal: trace AC_CONFIG_MACRO_DIR_TRACE

[Stefano Lattarini]

This is now the documented way, and indeed the only correct way, to
support AC_CONFIG_MACRO_DIR and AC_CONFIG_MACRO_DIRS in third-party
tools.  See autoconf commit v2.69-45-g5269030 of 2012-11-09,
"AC_CONFIG_MACRO_DIRS: improve tracing and add sanity checks".

* aclocal.in (trace_used_macros): Trace 'AC_CONFIG_MACRO_DIR_TRACE'
rather than 'AC_CONFIG_MACRO_DIRS'.  We still have to trace
'AC_CONFIG_MACRO_DIR' explicitly though, for compatibility with
Autoconf versions before 2.70.
* t/aclocal-macrodirs.tap: Enhance w.r.t. precedence of arguments
in one and several AC_CONFIG_MACRO_DIRS calls.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 aclocal.in              | 23 ++++++++++++++++-------
 t/aclocal-macrodirs.tap | 45 +++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/aclocal.in b/aclocal.in
index 264ad75..d4e7000 100644
--- a/aclocal.in
+++ b/aclocal.in
@@ -738,8 +738,11 @@ sub trace_used_macros ()
                     'AC_DEFUN_ONCE',
                     'AU_DEFUN',
                     '_AM_AUTOCONF_VERSION',
+                    # FIXME: We still need to trace AC_CONFIG_MACRO_DIR
+                     # for compatibility with older autoconf.  Remove this
+                     # when we can assume Autoconf 2.70 or later.
                     'AC_CONFIG_MACRO_DIR',
-                    'AC_CONFIG_MACRO_DIRS')),
+                    'AC_CONFIG_MACRO_DIR_TRACE')),
                   # Do not trace $1 for all other macros as we do
                   # not need it and it might contains harmful
                   # characters (like newlines).
@@ -769,18 +772,24 @@ sub trace_used_macros ()
         {
           $ac_version = $arg1;
         }
-      elsif ($macro eq 'AC_CONFIG_MACRO_DIR')
+      elsif ($macro eq 'AC_CONFIG_MACRO_DIR_TRACE')
         {
-          @ac_config_macro_dirs = ($arg1);
+          push @ac_config_macro_dirs, $arg1;
         }
-      elsif ($macro eq 'AC_CONFIG_MACRO_DIRS')
+    # FIXME: We still need to trace AC_CONFIG_MACRO_DIR
+    # for compatibility with older autoconf.  Remove this
+    # when we can assume Autoconf 2.70 or later.
+    elsif ($macro eq 'AC_CONFIG_MACRO_DIR')
         {
-          # Empty leading/trailing fields might be produced by split,
-          # hence the grep is really needed.
-          push @ac_config_macro_dirs, grep (/./, (split /\s+/, $arg1));
+          @ac_config_macro_dirs = ($arg1);
         }
     }
 
+  # FIXME: in Autoconf >= 2.70, AC_CONFIG_MACRO_DIR calls
+  # AC_CONFIG_MACRO_DIR_TRACE behind the scenes, which could
+  # leave unwanted duplicates in @ac_config_macro_dirs.
+  @ac_config_macro_dirs = uniq @ac_config_macro_dirs;
+
   $tracefh->close;
 
   return %traced;
diff --git a/t/aclocal-macrodirs.tap b/t/aclocal-macrodirs.tap
index a443e50..28abb7c 100755
--- a/t/aclocal-macrodirs.tap
+++ b/t/aclocal-macrodirs.tap
@@ -26,7 +26,7 @@ am_create_testdir=empty
 END
 } || skip_all_ "autoconf doesn't define the AC_CONFIG_MACRO_DIRS macro"
 
-plan_ 13
+plan_ 14
 
 ocwd=$(pwd) || fatal_ "getting current working directory"
 ACLOCAL_PATH=; unset ACLOCAL_PATH
@@ -119,7 +119,7 @@ three_dirs_check ()
 
 #---------------------------------------------------------------------------
 
-test_begin "AC_CONFIG_MACRO_DIRS: several arguments"
+test_begin "AC_CONFIG_MACRO_DIRS several arguments"
 
 cat > configure.ac <<'END'
 AC_INIT([more-args], [0.2])
@@ -135,7 +135,7 @@ test_end
 
 #---------------------------------------------------------------------------
 
-test_begin "AC_CONFIG_MACRO_DIRS: several calls"
+test_begin "AC_CONFIG_MACRO_DIRS several calls"
 
 cat > configure.ac <<'END'
 AC_INIT([more-calls], [2.0])
@@ -152,7 +152,7 @@ test_end
 
 #---------------------------------------------------------------------------
 
-test_begin "AC_CONFIG_MACRO_DIRS: extra whitespace"
+test_begin "AC_CONFIG_MACRO_DIRS extra whitespace"
 
 bslash=\\
 
@@ -174,6 +174,43 @@ test_end
 
 #---------------------------------------------------------------------------
 
+test_begin "AC_CONFIG_MACRO_DIRS precedence"
+
+cat > configure.ac <<'END'
+AC_INIT([more-calls], [2.0])
+AC_CONFIG_MACRO_DIRS([dir1])
+AC_CONFIG_MACRO_DIRS([dir2 dir3])
+MY_FOO
+MY_BAR
+MY_BAZ
+END
+
+mkdir dir1 dir2 dir3
+echo 'AC_DEFUN([MY_FOO], [OK-Foo])' > dir1/b.m4
+echo 'AC_DEFUN([MY_FOO], [KO-Foo])' > dir2/a.m4
+echo 'AC_DEFUN([MY_BAR], [OK-Bar])' > dir2/1.m4
+echo 'AC_DEFUN([MY_BAR], [KO-Bar])' > dir3/0.m4
+echo 'AC_DEFUN([MY_BAZ], [OK-Baz])' > dir3/x.m4
+
+$ACLOCAL \
+  && $FGREP 'm4_include([dir1/b.m4])' aclocal.m4 \
+  && $FGREP 'm4_include([dir2/1.m4])' aclocal.m4 \
+  && $FGREP 'm4_include([dir3/x.m4])' aclocal.m4 \
+  && test $($FGREP -c 'm4_include([dir1' aclocal.m4) -eq 1 \
+  && test $($FGREP -c 'm4_include([dir2' aclocal.m4) -eq 1 \
+  && test $($FGREP -c 'm4_include([dir3' aclocal.m4) -eq 1 \
+  && $AUTOCONF \
+  && not $EGREP 'MY_(FOO|BAR|BAZ)' configure \
+  && $FGREP 'OK-Foo' configure \
+  && $FGREP 'OK-Bar' configure \
+  && $FGREP 'OK-Baz' configure \
+  && not $FGREP 'KO-' configure \
+  || r='not ok'
+
+test_end
+
+#---------------------------------------------------------------------------
+
 test_begin "AC_CONFIG_MACRO_DIRS interaction with --install"
 
 cat > configure.ac << 'END'
-- 
1.8.0