maint: Ensure generated file reproducibility for dist.

* doc/local.mk (doc-clean): New target.
(DIST_CONFIGURE_FLAGS): New variable.
(auto-clean): Use them in new target.
* Makefile.am (dist-doc-pot-update): Use it in new target.
(dist): Change to depend on it to clean possibly stale files, instead of
doc-pot-update directly.
Add a toplevel check to ensure that Autotools cache is up to date.

Change-Id: I2ff2d88db9fe1e708ab65e33e1f3d7ecee882cb4

Makefile.am

@@ -954,9 +954,31 @@ guix-binary.%.tar.xz:
 	cp "$$tarball" "$@.tmp" ; mv "$@.tmp" "$@"
 
 
-# The dependency on doc-pot-update is to generate the .pot files, which are
-# not checked in.
-dist: doc-pot-update
+# Assert that Autotools cache is up to date with Git, by checking
+# PACKAGE_VERSION against HEAD.  Indented to get past Automake.
+ ifeq ($(MAKECMDGOALS),dist)
+ git_version = $(shell build-aux/git-version-gen .tarball-version)
+ ifneq ($(PACKAGE_VERSION),$(git_version))
+ $(warning Autotools cache out of date.)
+ $(info Autotools cache version: $(PACKAGE_VERSION).)
+ $(info Git version: $(git_version).)
+ $(info Please run ./bootstrap && ./configure $(DIST_CONFIGURE_FLAGS))
+ ifneq ($(GUIX_ALLOW_IRREPRODUCIBLE_TARBALL),yes)
+ $(error Cannot create reproducible tarball)
+ else
+ $(warning Tarball will be irreproducible; distdir will not get removed!)
+ endif
+ endif
+ endif
+
+# The dependency on dist-doc-pot-update is to clean possibly stale doc and po
+# files and only then generate the .pot files, which are not checked in.
+dist: dist-doc-pot-update
+dist-doc-pot-update: auto-clean
+	$(MAKE) guile$(EXEEXT)
+	$(MAKE) -C po/guix all
+	$(MAKE) -C po/packages all
+	$(MAKE) doc-pot-update
 
 dist-hook: gen-ChangeLog gen-AUTHORS gen-tarball-version
 dist-hook: assert-no-store-file-names

doc/local.mk

@@ -291,3 +291,38 @@ $(eval $(call version.texi-from-git,vti,doc/guix.texi,))
 $(foreach lang, $(MANUAL_LANGUAGES),							\
   $(eval i=$(shell echo $$(($(i)+1))))							\
   $(eval $(call version.texi-from-git,$(i),po/doc/guix-manual.$(lang).po,-$(lang))))
+
+DIST_CONFIGURE_FLAGS =				\
+  --localstatedir=/var				\
+  --sysconfdir=/etc
+
+# Delete all Autotools-generated files and rerun configure to ensure
+# a clean cache and distributing reproducible versions.
+auto-clean: maintainer-clean-vti doc-clean
+	rm -f ABOUT-NLS INSTALL
+	rm -f aclocal.m4 configure libtool Makefile.in
+	if test -e .git; then				\
+	    git clean -fdx -- '.am*' build-aux m4 po;	\
+	else						\
+	    rm -rf .am*;				\
+	    $(MAKE) -C po/guix maintainer-clean;	\
+	    $(MAKE) -C po/packages maintainer-clean;	\
+	fi
+	rm -f guile
+	rm -f guix-daemon nix/nix-daemon/guix_daemon-guix-daemon.o
+# Automake fails if guix-cookbook-LANG.texi stubs are missing; running
+# autoreconf -vif is not enough.
+	./bootstrap
+# The dependency chain for the guix-cookbook-LANG.texi was cut on purpose;
+# they must be deleted to ensure a rebuild.
+	rm -f $(filter-out %D%/guix.texi %D%/guix-cookbook.texi, $(info_TEXINFOS))
+	./configure $(DIST_CONFIGURE_FLAGS)
+
+# Delete all generated doc files to ensure a clean cache and distributing
+# reproducible versions.
+doc-clean:
+	rm -f $(srcdir)/doc/*.1
+	rm -f $(srcdir)/doc/stamp*
+	rm -f $(DOT_FILES:%.dot=%.png)
+	rm -f $(DOT_VECTOR_GRAPHICS)
+	rm -f doc/images/coreutils-size-map.eps