build-sys: improve changelog target

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/Makefile.am b/Makefile.am
index 03255592691ecf879321b9e8fb421b15febee4d3..7bd0b37c41f2ec54d43e87a7b9e4a637cbaba5a3 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -100,8 +100,9 @@ BUILT_SOURCES = .version
        echo $(VERSION) > $@-t && mv $@-t $@
 
 CHANGELOG_FILE = v$(VERSION)-ChangeLog
-changelog:
-       if test "x$$PREVIOUS_VERSION" == "x"; then \
+
+$(CHANGELOG_FILE):
+       @ if test "x$$PREVIOUS_VERSION" == "x"; then \
                echo "Usage make changelog PREVIOUS_VERSION=<version>"; \
                exit 1; \
        fi
@@ -110,3 +111,6 @@ changelog:
        @ echo >> $(CHANGELOG_FILE)
        $(AM_V_GEN) git log --stat v$(PREVIOUS_VERSION)..HEAD >> $(CHANGELOG_FILE)
 
+changelog: $(CHANGELOG_FILE)
+
+