changeset 13100:61dece5578fb

gnumakefile: don't squelch _version output Borrowing from a trick I discovered on the libvirt list. More details about how this trick works: GNU make parses all Makefiles, then checks whether they are up-to-date, all before making anything else; if any Makefile timestamps change, then it restarts with the original arguments and repeats the check for up-to-date Makefiles (assuming that this time the check will pass). Since all the rules are parsed before Makefile is updated, proceeding without reloading Makefiles would result in the use of the stale $(VERSION) string that was in effect when we first started, so we must update a timestamp to force the reload. However, if we made Makefile depend on _version, we would end up running _version twice. So instead, we make _version run a recursive make to update Makefile (the recursive make skips the rules for checking whether the version string needs an update, avoiding any extra runs of _version), then ensure that GNUmakefile has an updated timestamp to force the reload of the updated Makefile. * top/GNUmakefile (GNUmakefile): Create one-shot dependency rather than using $(shell) to run _version target. (_autoreconf): Run verbosely, by default. Signed-off-by: Eric Blake <eblake@redhat.com>
author Eric Blake <eblake@redhat.com>
date Tue, 30 Mar 2010 15:56:17 -0600
parents f4aae3195883
children 8dad7d30953c
files ChangeLog top/GNUmakefile
diffstat 2 files changed, 9 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2010-03-31  Eric Blake  <eblake@redhat.com>
 
+	gnumakefile: don't squelch _version output
+	* top/GNUmakefile (_version): Create one-shot dependency rather
+	than using $(shell) when version must be regenerated.
+	(_autoreconf): Run verbosely, by default.
+
 	sys_time: avoid compiler warnings
 	* lib/sys_time.in.h (includes): Ensure gcc pragma is
 	unconditional, fixing regression from 2010-03-29.
--- a/top/GNUmakefile
+++ b/top/GNUmakefile
@@ -49,7 +49,7 @@
 
 # Allow cfg.mk to override these.
 _build-aux ?= build-aux
-_autoreconf ?= autoreconf
+_autoreconf ?= autoreconf -v
 
 # Ensure that $(VERSION) is up to date for dist-related targets, but not
 # for others: rerunning autoreconf and recompiling everything isn't cheap.
@@ -78,7 +78,8 @@
           $(info run '$(MAKE) _version' to fix it)
         else
           $(info INFO: running autoreconf for new version string: $(_curr-ver))
-          _dummy := $(shell $(MAKE) $(AM_MAKEFLAGS) _version)
+GNUmakefile: _version
+	touch GNUmakefile
         endif
       endif
     endif
@@ -88,6 +89,7 @@
 .PHONY: _version
 _version:
 	cd $(srcdir) && rm -rf autom4te.cache .version && $(_autoreconf)
+	$(MAKE) $(AM_MAKEFLAGS) Makefile
 
 else