Make sure ChangeLog is built by make

* Makefile.am: Mark ChangeLog as noinst_DATA to trigger
its rule.  Rewrite the ChangeLog rule using a wrapper
over gitlog-to-changelog, which rewrites the file only
when needed.
(dist-hook): Fail if there are uncommitted changes.
* mu-aux/gencl: New file.

* maint.mk: Remove.

3 files changed, 144 insertions, 112 deletions

diff --git a/Makefile.am b/Makefile.am
index f7913ab9b..5e6968226 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -123,45 +123,45 @@ SUBDIRS = . \
 EXTRA_DIST = COPYING.LESSER paths
 DISTCLEANFILES = pathdefs.h
 
+# Trigger creation of the ChangeLog
+noinst_DATA = ChangeLog
+
 gen_start_date = "2008-12-08"
 prev_change_log = "doc/ChangeLog.CVS"
 amend_file=ChangeLog.amend
 
 .PHONY: ChangeLog
-ChangeLog:
-	@if test -d .git; then                                             \
-	  cmd="$(top_srcdir)/build-aux/gitlog-to-changelog";               \
-	  if test -n "$(amend_file)"; then                                 \
-            cmd="$$cmd --amend=$(amend_file)";                             \
-          fi;                                                              \
-	  if test -n "$(gen_start_date)"; then                             \
-	    cmd="$$cmd --since=\"$(gen_start_date)\"";                     \
-	  fi;                                                              \
-	  $$cmd --format='%s%n%n%b%n' |                                    \
-            sed '/<unknown>$$/d' | fmt -s > cl-t;                          \
-          if test -n "$(prev_change_log)" && test -f "$(prev_change_log)"; \
-	  then                                                             \
-	    echo "" >> cl-t;                                               \
-	    cat "$(prev_change_log)" |                                     \
-	      sed '/^Local Variables:/,/^End:/d' >> cl-t;                  \
-	  fi;                                                              \
-	  echo "Local Variables:" >> cl-t;                                 \
-	  echo "mode: change-log" >> cl-t;                                 \
-	  echo "version-control: never"  >> cl-t;                          \
-	  echo "buffer-read-only: t" >> cl-t;                              \
-	  echo "End:" >> cl-t;                                             \
-	  rm -f ChangeLog;                                                 \
-	  mv cl-t ChangeLog;                                               \
+ChangeLog: 
+	$(AM_V_at)if test -d .git; then					\
+	    cmd="$(top_srcdir)/mu-aux/gencl --file=ChangeLog --verbose";\
+            if test -n "$(prev_change_log)" && test -f "$(prev_change_log)"; \
+	    then							\
+		cmd="$$cmd --append=$(prev_change_log)";		\
+	    fi;								\
+	    cmd="$$cmd -- $(top_srcdir)/build-aux/gitlog-to-changelog"; \
+	    if test -n "$(amend_file)"; then                                 \
+              cmd="$$cmd --amend=$(amend_file)";                             \
+            fi;                                                              \
+	    if test -n "$(gen_start_date)"; then                             \
+	      cmd="$$cmd --since=\"$(gen_start_date)\"";                     \
+	    fi;                                                              \
+	    $$cmd --format='%s%n%n%b%n' | fmt -s;	                     \
 	fi
 
 dist-hook: ChangeLog
-	@PATCHLEV=`echo "$(PACKAGE_VERSION)" | \
-                   sed -r "s/[0-9]+\.[0-9]+\.?//"`; \
-	if test $${PATCHLEV:-0} -lt 50; then \
-		if grep -q FIXME NEWS; then \
-			echo >&2 "NEWS file contains FIXMEs"; \
-			exit 1; \
-		fi; \
+	@if head -n 6 ChangeLog | grep -q 'Uncommitted changes' ;	     \
+	then								     \
+	  echo >&2 "*** Source tree contains uncommitted changes";	     \
+	  echo >&2 "*** Aborting";					     \
+	  exit 1;							     \
+	fi;								     \
+	PATCHLEV=`echo "$(PACKAGE_VERSION)" | sed -r "s/[0-9]+\.[0-9]+\.?//"`;\
+	if test $${PATCHLEV:-0} -lt 50; then				     \
+	  if grep -q FIXME NEWS; then					     \
+	    echo >&2 "*** NEWS file contains FIXMEs";			     \
+	    echo >&2 "*** Aborting";					     \
+	    exit 1;							     \
+	  fi;								     \
 	fi
 
 alpha:
diff --git a/maint.mk b/maint.mk
deleted file mode 100644
index 63bb79335..000000000
--- a/maint.mk
+++ /dev/null
@@ -1,81 +0,0 @@
-# This file is part of GNU Mailutils.
-# Copyright (C) 2009-2012, 2014-2017 Free Software Foundation, Inc.
-#
-# Written by Sergey Poznyakoff
-#
-# GNU Mailutils is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3, or (at your option)
-# any later version.
-#
-# GNU Mailutils is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
-
-include Makefile
-
-CFLOW_FLAGS=-i^s --brief -v
-
-MAINT_CLEAN_FILES=
-
-define flowgraph_tmpl
-MAINT_CLEAN_FILES += $(1).cflow
-$(2)_CFLOW_INPUT=$$($(2)_OBJECTS:.$(3)=.c)
-$(1).cflow: $$($(2)_CFLOW_INPUT) Makefile
-	cflow -o$$@ $$(CFLOW_FLAGS) $$(DEFS) \
-		$$(DEFAULT_INCLUDES) $$(INCLUDES) $$(AM_CPPFLAGS) \
-		$$(CPPFLAGS) \
-	$$($(2)_CFLOW_INPUT)
-endef
-
-$(foreach prog,$(bin_PROGRAMS) $(sbin_PROGRAMS),\
-$(eval $(call flowgraph_tmpl,$(prog),$(subst -,_,$(prog)),$(OBJEXT))))
-
-$(foreach prog,$(lib_LTLIBRARIES),\
-$(eval $(call flowgraph_tmpl,$(prog),$(subst .,_,$(prog)),lo)))
-
-all: flowgraph-recursive
-
-flowgraph: $(foreach prog,$(bin_PROGRAMS) $(sbin_PROGRAMS) $(lib_LTLIBRARIES),$(prog).cflow)
-
-maintclean:
-	-test -n "$(MAINT_CLEAN_FILES)" && rm -f $(MAINT_CLEAN_FILES)
-
-##
-
-MAINT_MK = maint.mk
-
-MAINT_RECURSIVE_TARGETS=flowgraph-recursive maintclean-recursive
-
-$(MAINT_RECURSIVE_TARGETS):
-	@cwd=`pwd`; \
-	failcom='exit 1'; \
-	for f in x $$MAKEFLAGS; do \
-	  case $$f in \
-	    *=* | --[!k]*);; \
-	    *k*) failcom='fail=yes';; \
-	  esac; \
-	done; \
-	dot_seen=no; \
-	target=`echo $@ | sed s/-recursive//`; \
-	list='$(SUBDIRS)'; for subdir in $$list; do \
-	  echo "Making $$target in $$subdir"; \
-	  if test "$$subdir" = "."; then \
-	    dot_seen=yes; \
-	    local_target="$$target-am"; \
-	  else \
-	    local_target="$$target"; \
-	  fi; \
-	  if test -f $$subdir/$(MAINT_MK); then \
-	    makefile='$(MAINT_MK)'; \
-	  else \
-	    makefile="$$cwd/maint.mk"; \
-	  fi; \
-	  $(MAKE) -C $$subdir -f $$makefile $$local_target \
-	     || eval $$failcom; \
-	done; \
-	test -z "$$fail"
diff --git a/mu-aux/gencl b/mu-aux/gencl
new file mode 100755
index 000000000..af6056bd5
--- /dev/null
+++ b/mu-aux/gencl
@@ -0,0 +1,113 @@
+eval '(exit $?0)' && eval 'exec perl -wS "$0" "$@"'
+  & eval 'exec perl -wS "$0" $argv:q'
+    if 0;
+
+use strict;
+use POSIX qw(strftime);
+use Getopt::Long qw(:config gnu_getopt no_ignore_case);
+
+my @append_files;
+my $force;
+my $verbose;
+my $changelog_file = 'ChangeLog';
+
+GetOptions('append|a=s@' => \@append_files,
+	   'file|F=s' => \$changelog_file,
+	   'force|f' => \$force,
+	   'verbose|v' => \$verbose) or exit(1);
+
+if (! -d '.git') {
+    exit 0;
+}
+
+my ($hash, $date) = split / /, `git log --max-count=1 --pretty=format:'%H %ad' --date=short HEAD`;
+
+my @modlines;
+if (open(my $fd, '-|', 'git diff-index --name-status HEAD 2>/dev/null')) {
+    chomp(@modlines = map {chomp; [split /\s+/, $_, 2]} <$fd>);
+    close $fd;
+}
+
+if (@modlines) {
+    $date = strftime '%Y-%m-%d', localtime;
+}
+
+my @header;
+
+push @header, "$date  Automatically generated  <bug-mailutils\@gnu.org>";
+push @header, '';
+push @header, "\tHEAD $hash";
+push @header, '';
+
+my %status = (
+    A => 'New file',
+    C => 'Copied file',
+    D => 'Removed file',
+    M => 'Changed',
+    R => 'Renamed',
+    T => 'Type change',
+    U => 'Unmerged',
+    X => 'Unknown'
+);
+
+if (@modlines) {
+    push @header, "\tUncommitted changes:";
+    push @header, '';
+
+    push @header, map {
+	"\t* $_->[1]: " . ($status{$_->[0]} || 'Unknown') . ";"
+    } @modlines;
+    push @header, '';
+}
+
+sub headcmp {
+    my $file = shift;
+    if (open(my $fd, '<', $changelog_file)) {
+	while (<$fd>) {
+	    my $line = shift;
+	    last unless defined($line);
+	    chomp;
+	    return 0 unless $line eq $_;
+	}
+	return 1 unless @_;
+    }
+    return 0;
+}
+
+if (!$force && headcmp($changelog_file, @header)) {
+    exit 0;
+}
+
+print "  GEN $changelog_file\n" if $verbose;
+close STDOUT;
+
+open(STDOUT, '>', $changelog_file)
+    or die "Can't open $changelog_file for writing: $!";
+
+for (@header) {
+    print "$_\n";
+}
+
+system(@ARGV);
+foreach my $file (@append_files) {
+    if (open(my $fd, '<', $file)) {
+	while (<$fd>) {
+	    chomp;
+	    last if /^Local Variables:/;
+	    next if /^\f$/;
+	    print "$_\n";
+	}
+	close $fd;
+    } else {
+	warn "can't open $file: $!";
+    }
+}
+
+print "\f\nLocal Variables:\n";
+print <<'EOT';
+mode: change-log
+version-control: never
+buffer-read-only: t
+End:
+EOT
+;