cleanup: refactor code to initialize DIST_COMMON

There is not need to make that an Automake variable early,
only to later get and munge its contents, and use the new
content to redefine the variable.

* bin/automake.in (@dist_common): New global variable.
(push_dist_common, handle_dist): Use it.
(handle_dist): Define am__DIST_COMMON instead of DIST_COMMON
directly.
(initialize_per_input): Reset it to empty.
($configure_dist_common): Turn this scalar variable ...
(@configure_dist_common): ... into this array variable.
(handle_dist): Adjust.
(required_file_check_or_copy): Update and wrap some comments.
* lib/am/distdir.am (DIST_COMMON): Append $(am__DIST_COMMON).
* t/distcom2.sh: Tighten a little.

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

3 files changed, 26 insertions, 25 deletions

diff --git a/bin/automake.in b/bin/automake.in
index 785145498..d48b2863d 100644
--- a/bin/automake.in
+++ b/bin/automake.in
@@ -342,7 +342,7 @@ my %extension_map = ();
 
 # List of the DIST_COMMON files we discovered while reading
 # configure.ac.
-my $configure_dist_common = '';
+my @configure_dist_common = ();
 
 # This maps languages names onto objects.
 my %languages = ();
@@ -489,6 +489,9 @@ my %language_scratch;
 # handling on a per-language basis.
 my %lang_specific_files;
 
+# List of distributed files to be put in DIST_COMMON.
+my @dist_common;
+
 # This is set when 'handle_dist' has finished.  Once this happens,
 # we should no longer push on dist_common.
 my $handle_dist_run;
@@ -586,8 +589,11 @@ sub initialize_per_input ()
 
     @dist_targets = ();
 
+    @dist_common = ();
+    $handle_dist_run = 0;
+
     %known_programs = ();
-    %known_libraries= ();
+    %known_libraries = ();
 
     %extension_seen = ();
 
@@ -595,8 +601,6 @@ sub initialize_per_input ()
 
     %lang_specific_files = ();
 
-    $handle_dist_run = 0;
-
     $need_link = 0;
 
     $must_handle_compiled_objects = 0;
@@ -3693,8 +3697,8 @@ sub handle_dist ()
 	}
     }
 
-  # We might copy elements from $configure_dist_common to
-  # %dist_common if we think we need to.  If the file appears in our
+  # We might copy elements from @configure_dist_common to
+  # @dist_common if we think we need to.  If the file appears in our
   # directory, we would have discovered it already, so we don't
   # check that.  But if the file is in a subdir without a Makefile,
   # we want to distribute it here if we are doing '.'.  Ugly!
@@ -3706,26 +3710,25 @@ sub handle_dist ()
   # See also automake bug#9651.
   if ($relative_dir eq '.')
     {
-      foreach my $file (split (' ' , $configure_dist_common))
+      foreach my $file (@configure_dist_common)
 	{
 	  my $dir = dirname ($file);
 	  push_dist_common ($file)
 	    if ($dir eq '.' || ! is_make_dir ($dir));
 	}
+      @configure_dist_common = ();
     }
 
-  # Files to distributed.  Don't use ->value_as_list_recursive as it
-  # recursively expands '$(dist_pkgdata_DATA)' etc.
+  # $(am__DIST_COMMON): files to be distributed automatically.  Will be
+  # appended to $(DIST_COMMON) in the generated Makefile.
   # Use 'sort' so that the expansion of $(DIST_COMMON) in the generated
   # Makefile is deterministic, in face of m4 and/or perl randomizations
   # (see automake bug#17908).
-  my @dist_common = split (' ', rvar ('DIST_COMMON')->variable_value);
-  @dist_common = uniq (sort @dist_common);
-  variable_delete 'DIST_COMMON';
-  define_pretty_variable ('DIST_COMMON', TRUE, INTERNAL, @dist_common);
+  define_pretty_variable ('am__DIST_COMMON', TRUE, INTERNAL,
+                          uniq (sort @dist_common));
 
-  # Now that we've processed DIST_COMMON, disallow further attempts
-  # to set it.
+  # Now that we've processed @dist_common, disallow further attempts
+  # to modify it.
   $handle_dist_run = 1;
 
   $transform{'DISTCHECK-HOOK'} = !! rule 'distcheck-hook';
@@ -5435,8 +5438,7 @@ sub scan_autoconf_files ()
     if -f $config_aux_dir . '/install.sh';
 
   # Preserve dist_common for later.
-  $configure_dist_common = variable_value ('DIST_COMMON') || '';
-
+  @configure_dist_common = @dist_common;
 }
 
 ################################################################
@@ -7402,11 +7404,10 @@ sub required_file_check_or_copy
   return
     if $found_it && (! $add_missing || ! $force_missing);
 
-  # If we've already looked for it, we're done.  You might
-  # wonder why we don't do this before searching for the
-  # file.  If we do that, then something like
-  # AC_OUTPUT(subdir/foo foo) will fail to put foo.in into
-  # DIST_COMMON.
+  # If we've already looked for it, we're done.  You might wonder why we
+  # don't do this before searching for the file.  If we do that, then
+  # something like AC_OUTPUT([subdir/foo foo]) will fail to put 'foo.in'
+  # into $(DIST_COMMON).
   if (! $found_it)
     {
       return if defined $required_file_not_found{$fullfile};
@@ -7693,8 +7694,7 @@ sub push_dist_common
 {
   prog_error "push_dist_common run after handle_dist"
     if $handle_dist_run;
-  Automake::Variable::define ('DIST_COMMON', VAR_AUTOMAKE, '+', TRUE, "@_",
-			      '', INTERNAL, VAR_PRETTY);
+  push @dist_common, @_;
 }
 
 
diff --git a/lib/am/distdir.am b/lib/am/distdir.am
index 0c019605c..5a13055fc 100644
--- a/lib/am/distdir.am
+++ b/lib/am/distdir.am
@@ -14,6 +14,7 @@
 ## You should have received a copy of the GNU General Public License
 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+DIST_COMMON += $(am__DIST_COMMON)
 DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
 
 if %?TOPDIR_P%
diff --git a/t/distcom2.sh b/t/distcom2.sh
index 0cb9307d4..3eb03762d 100644
--- a/t/distcom2.sh
+++ b/t/distcom2.sh
@@ -52,7 +52,7 @@ for opt in '' --no-force; do
 
   for dir in . subdir; do
     sed -n -e "
-      /^\\(am__\\)\\?DIST_COMMON =.*/ {
+      /^am__DIST_COMMON =.*/ {
         b body
         :loop
         n