From: Mike Brady <4265913+mikebrady@users.noreply.github.com>
Date: Mon, 5 Aug 2024 17:20:26 +0000 (+0100)
Subject: Use check-gitversion for improved use of 'git describe' information for versioning.
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a93ba708af9e7aa65e16dac375a833426bd3bf04;p=thirdparty%2Fnqptp.git

Use check-gitversion for improved use of 'git describe' information for versioning.
---

diff --git a/.gitignore b/.gitignore
index b54d1df..436b0f9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -53,6 +53,7 @@ Makefile
 # Executable
 nqptp
 
-# Version file generated from '$ git describe --dirty'
+# Version files generated from check-gitversion
 gitversion.h
+gitversion-stamp
 
diff --git a/Makefile.am b/Makefile.am
index b25fbff..22771a7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2,20 +2,17 @@ bin_PROGRAMS = nqptp
 nqptp_SOURCES = nqptp.c nqptp-clock-sources.c nqptp-message-handlers.c nqptp-utilities.c general-utilities.c debug.c
 
 AM_CFLAGS = -fno-common -Wall -Wextra -pthread --include=config.h
-CLEANFILES =
+
 
 if USE_GIT_VERSION
-nqptp.c: gitversion.h
-gitversion.h: .git/index
-	echo "// Do not edit!" > gitversion.h
-	echo "// This file is automatically generated by 'git describe --tags --dirty --broken', if available." >> gitversion.h
-	echo -n "  char git_version_string[] = \"" >> gitversion.h
-	git describe --tags --dirty --broken | tr -d '[[:space:]]' >> gitversion.h
-	echo "\";" >> gitversion.h
-FORCE: ;
-CLEANFILES += gitversion.h
-endif
+## Check if the git version information has changed and rebuild gitversion.h if so
+.PHONY: gitversion-check
+gitversion-check: 
+	$(top_srcdir)/check-gitversion
 
+BUILT_SOURCES = gitversion-check
+CLEANFILES = gitversion-stamp gitversion.h
+endif
 
 install-exec-hook:
 if BUILD_FOR_LINUX
diff --git a/check-gitversion b/check-gitversion
new file mode 100755
index 0000000..a1c8a9f
--- /dev/null
+++ b/check-gitversion
@@ -0,0 +1,37 @@
+#! /bin/sh
+# echo "This is the git version checker"
+test -f gitversion-stamp && BGD=`cat gitversion-stamp` || :
+# echo "existing gitversion-stamp is $BGD"
+GD=`git describe --tags --dirty --broken --always 2>/dev/null`
+if [ x"$GD" = x ] ; then
+  GD="NA"
+fi
+# echo "current git description is $GD"
+if [ x"$GD" != x"$BGD" ] ; then
+  echo "build: $GD" # optional -- displays git version if new or different
+  echo $GD > gitversion-stamp
+  echo "// Do not edit!" > gitversion.h
+	echo "// This file is automatically generated." >> gitversion.h
+	echo -n "  char git_version_string[] = \"" >> gitversion.h
+	## the tr is because we need to remove the trailing newline
+	cat gitversion-stamp | tr -d '[[:space:]]' >> gitversion.h
+	echo "\";" >> gitversion.h
+fi
+
+# Usage. Below is what you would add to Makefile.am. When it runs, the
+# following two files are generated: 'gitversion-stamp' and 'gitversion.h'.
+
+# gitversion-stamp stores the most recently used git description.
+# gitversion.h is a C header file containing that git description as a string.
+
+# Put this script in the top level source folder and make sure it has execute permission.
+
+# These are the lines (remove the leading '#' on each) to add to the Makefile.am file:
+# ## Check if the git version information has changed and rebuild gitversion.h if so.
+# .PHONY: gitversion-check
+# gitversion-check: 
+# 	$(top_srcdir)/check-gitversion
+
+# ## You may have to change from += to = below:
+# BUILT_SOURCES += gitversion-check
+# CLEANFILES += gitversion-stamp gitversion.h