build: Use AX_GENERATE_CHANGELOG to generate ChangeLog

This removes some Makefile.am rules and simplifies the build system a
bit.

Signed-off-by: Philip Withnall <philip.withnall@collabora.co.uk>
Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D4912

ChangeLog

+The ChangeLog is auto-generated when releasing.
+If you are seeing this, use 'git log' for a detailed list of changes.

Makefile.am

@@ -754,23 +754,7 @@ EXTRA_DIST += \
 	$(NULL)
 
 # ChangeLog
-ChangeLog: $(srcdir)/ChangeLog
-$(srcdir)/ChangeLog:
-	@echo Creating $@
-	@if test -d "$(srcdir)/.git"; then \
-	  (GIT_DIR=$(top_srcdir)/.git ./build-aux/missing --run \
-	   git log --stat) | fmt --split-only > $@.tmp \
-	  && mv -f $@.tmp $@ \
-	  || ($(RM) $@.tmp; \
-	      echo Failed to generate ChangeLog, your ChangeLog may be outdated >&2; \
-	      (test -f $@ || echo git-log is required to generate this file >> $@)); \
-	else \
-	  test -f $@ || \
-	  (echo A git checkout and git-log is required to generate ChangeLog >&2 && \
-	  echo A git checkout and git-log is required to generate this file >> $@); \
-	fi
-.PHONY: $(srcdir)/ChangeLog
-
-MAINTAINERCLEANFILES += ChangeLog
+@GENERATE_CHANGELOG_RULES@
+dist-hook: dist-ChangeLog
 
 -include $(top_srcdir)/git.mk

configure.ac

@@ -146,6 +146,7 @@ AX_CODE_COVERAGE
 # General macros
 AX_COMPILER_FLAGS
 AX_VALGRIND_CHECK
+AX_GENERATE_CHANGELOG
 
 GOBJECT_INTROSPECTION_CHECK([0.9.7])
 

debian/source/options

-extend-diff-ignore = ^git\.mk$|^\.arcconfig$
+extend-diff-ignore = ^git\.mk$|^\.arcconfig$|^ChangeLog$