[FYI 1/2] {master} tags: refactor to reduce code duplication (1)

[Stefano Lattarini]

No semantic change is intended.

* lib/am/tags.am (am__uniquify_input): New variable, factor
out some code common to ...
(ctags-am, tags-am, ID): ... the recipes of these targets.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 lib/am/tags.am | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/lib/am/tags.am b/lib/am/tags.am
index 26a9f13..28338a7 100644
--- a/lib/am/tags.am
+++ b/lib/am/tags.am
@@ -14,6 +14,15 @@
 ## You should have received a copy of the GNU General Public License
 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+# Read a list of newline-separated strings from the standard input,
+# and print each of them once, without duplicates.  Input order is
+# *not* preserved.
+am__uniquify_input = $(AWK) '\
+  BEGIN { nonempty = 0; } \
+  { items[$$0] = 1; nonempty = 1; } \
+  END { if (nonempty) { for (i in items) print i; }; } \
+'
+
 ## ---- ##
 ## ID.  ##
 ## ---- ##
@@ -24,9 +33,7 @@ ID: $(am__tagged_files)
        unique=`for i in $$list; do \
 ## Handle VPATH correctly.
            if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
-         done | \
-         $(AWK) '{ files[$$0] = 1; nonempty = 1; } \
-             END { if (nonempty) { for (i in files) print i; }; }'`; \
+         done | $(am__uniquify_input)`;
        mkid -fID $$unique
 
 
@@ -75,9 +82,7 @@ tags-am: $(TAGS_DEPENDENCIES) $(am__tagged_files)
        unique=`for i in $$list; do \
 ## Handle VPATH correctly.
            if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
-         done | \
-         $(AWK) '{ files[$$0] = 1; nonempty = 1; } \
-             END { if (nonempty) { for (i in files) print i; }; }'`; \
+         done | $(am__uniquify_input)`; \
 ## Remove the 'x' we added first:
        shift; \
 ## Make sure we have something to run etags on.
@@ -114,9 +119,7 @@ ctags-am: $(TAGS_DEPENDENCIES) $(am__tagged_files)
        unique=`for i in $$list; do \
 ## Handle VPATH correctly.
            if test -f "$$i"; then echo $$i; else echo $(srcdir)/$$i; fi; \
-         done | \
-         $(AWK) '{ files[$$0] = 1; nonempty = 1; } \
-             END { if (nonempty) { for (i in files) print i; }; }'`; \
+         done | $(am__uniquify_input)`; \
 ## Make sure we have something to run ctags on.
        test -z "$(CTAGS_ARGS)$$unique" \
          || $(CTAGS) $(CTAGSFLAGS) $(AM_CTAGSFLAGS) $(CTAGS_ARGS) \
-- 
1.7.12.rc0