New autoconf feature from Ralf Corsepius:

  It adds make rules for reconfiguring build-trees ("make Makefile") and
  adds dependency rules for configure and friends (i.e. calls autoconf).
  Most of this code has been "borrowed" from automake and was adapted to
  rtems.

  Addionally, I added automatic generation of the "aclocal.m4"-file by
  "aclocal" (from the automake package). Therefore I splitted aclocal.m4
  into several separate files (attached to this mail), each containing one
  of rtems customized autoconf/m4-macros and have put them into a new
  subdirectory "aclocal". Normal users won't be influenced and won't even
  need this, unless they try to modify configure.in.

  The main advantage of this is: these aclocal/m4-macros become reusable
  and easier to administer. As a disadvantage, rtems becomes dependent of
  having aclocal/automake installed. To keep building rtems functional if
  autoconf or aclocal isn't installed, the related Makefile commands are
  prefixed by "-" -- only an error message should be issued by "make".

1 files changed, 22 insertions, 0 deletions

diff --git a/Makefile.in b/Makefile.in
index 61a8f0a95f..95d3c28ffb 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -49,3 +49,25 @@ $(MTARGETS):
             $@" ; \
 	    eval $$cmd || $(EXIT_CMD); \
 	fi; done; 
+
+## Configuration stuff
+
+ACLOCAL = aclocal -I aclocal
+AUTOCONF = autoconf
+
+ACLOCAL_M4 = aclocal.m4
+
+$(ACLOCAL_M4): configure.in
+	-cd $(RTEMS_ROOT) && $(ACLOCAL)
+
+Makefile: Makefile.in config.status
+	CONFIG_FILES=$@ CONFIG_HEADERS= $(SHELL) ./config.status
+
+config.status: $(RTEMS_ROOT)/configure
+	$(SHELL) ./config.status --recheck
+
+$(RTEMS_ROOT)/configure: $(RTEMS_ROOT)/configure.in $(ACLOCAL_M4)
+	-cd $(RTEMS_ROOT) && $(AUTOCONF)
+
+.PRECIOUS: $(ACLOCAL_M4) configure Makefile config.status
+