[ng] subdirs: use static pattern rules to define *-recursive targets

* lib/am/subdirs.am ($(RECURSIVE_TARGETS), $(RECURSIVE_CLEAN_TARGETS)):
Rewrite as static pattern rules.  This will also simplify their recipes,
avoid extra processing by the shell, and shave off a couple of forks.

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

diff --git a/lib/am/subdirs.am b/lib/am/subdirs.am
index 5dfe8ca84d8f0f8775fca7b9ec4f07c7a9010e5a..98a7010f7d6b1bdd5cddf5a9e9fca0abbda7cbb6 100644 (file)
--- a/lib/am/subdirs.am
+++ b/lib/am/subdirs.am
@@ -31,7 +31,7 @@ AM_RECURSIVE_TARGETS += $(RECURSIVE_TARGETS:-recursive=) \
 #     (which will cause the Makefiles to be regenerated when you run 'make');
 # (2) otherwise, pass the desired values on the 'make' command line.
 
-$(RECURSIVE_TARGETS) $(RECURSIVE_CLEAN_TARGETS):
+$(RECURSIVE_TARGETS) $(RECURSIVE_CLEAN_TARGETS): %-recursive:
 ## Using $failcom allows "-k" to keep its natural meaning when running a
 ## recursive rule.
        @fail= failcom='exit 1'; \
@@ -42,7 +42,6 @@ $(RECURSIVE_TARGETS) $(RECURSIVE_CLEAN_TARGETS):
          esac; \
        done; \
        dot_seen=no; \
-       target=`echo $@ | sed s/-recursive//`; \
 ## For distclean and maintainer-clean we make sure to use the full
 ## list of subdirectories.  We do this so that 'configure; make
 ## distclean' really is a no-op, even if SUBDIRS is conditional.
@@ -51,17 +50,17 @@ $(RECURSIVE_TARGETS) $(RECURSIVE_CLEAN_TARGETS):
          *) list='$(SUBDIRS)' ;; \
        esac; \
        for subdir in $$list; do \
-         echo "Making $$target in $$subdir"; \
+         echo "Making $* in $$subdir"; \
          if test "$$subdir" = "."; then \
            dot_seen=yes; \
-           local_target="$$target-am"; \
+           local_target=$*-am; \
          else \
-           local_target="$$target"; \
+           local_target=$*; \
          fi; \
          $(MAKE) -C "$$subdir" $$local_target || eval $$failcom; \
        done; \
        if test "$$dot_seen" = "no"; then \
-         $(MAKE) "$$target-am" || exit 1; \
+         $(MAKE) $*-am || exit 1; \
        fi; test -z "$$fail"