[PATCH] build: dynamically generate version number

[PATCH] build: dynamically generate version number

[Eric Wong]

This should make development a bit easier
---
 .gitignore      |  1 +
 GIT-VERSION-GEN | 42 ++++++++++++++++++++++++++++++++++++++++++
 GNUmakefile     |  4 +++-
 lib/olddoc.rb   |  2 --
 olddoc.gemspec  |  1 +
 5 files changed, 47 insertions(+), 3 deletions(-)
 create mode 100755 GIT-VERSION-GEN

diff --git a/.gitignore b/.gitignore
index 2a6e67a..d873717 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,4 @@ LATEST
 .gem-manifest
 .tgz-manifest
 /doc
+/lib/olddoc/version.rb
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
new file mode 100755
index 0000000..7199e19
--- /dev/null
+++ b/GIT-VERSION-GEN
@@ -0,0 +1,42 @@
+#!/usr/bin/env ruby
+# Copyright (C) 2016 all contributors <olddoc-public@80x24.org>
+# License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
+# frozen_string_literal: true
+CONSTANT = "Olddoc::VERSION"
+RVF = "lib/olddoc/version.rb"
+GVF = "GIT-VERSION-FILE"
+DEF_VER = "v1.3.0.GIT"
+vn = DEF_VER.dup
+
+# First see if there is a version file (included in release tarballs),
+# then try git-describe, then default.
+if File.exist?(".git")
+  describe = `git describe --abbrev=4 HEAD 2>/dev/null`.strip
+  case describe
+  when /\Av[0-9]*/
+    vn = describe
+    system(*%w(git update-index -q --refresh))
+    unless `git diff-index --name-only HEAD --`.chomp.empty?
+      vn << "-dirty"
+    end
+    vn.tr!('-', '.')
+  end
+end
+
+vn = vn.sub!(/\Av/, "")
+new_ruby_version = "#{CONSTANT} = '#{vn}'.freeze # :nodoc:\n"
+cur_ruby_version = File.read(RVF) rescue nil
+if new_ruby_version != cur_ruby_version
+  File.open(RVF, "w") { |fp| fp.write(new_ruby_version) }
+end
+File.chmod(0644, RVF)
+
+# generate the makefile snippet
+new_make_version = "VERSION = #{vn}\n"
+cur_make_version = File.read(GVF) rescue nil
+if new_make_version != cur_make_version
+  File.open(GVF, "w") { |fp| fp.write(new_make_version) }
+end
+File.chmod(0644, GVF)
+
+puts vn if $0 == __FILE__
diff --git a/GNUmakefile b/GNUmakefile
index f67cab6..1e07a44 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -3,7 +3,9 @@
 all::
 pkg = olddoc
 RUBY = ruby
-VERSION := $(shell $(RUBY) -Ilib -rolddoc -e 'puts Olddoc::VERSION')
+GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE
+	@./GIT-VERSION-GEN
+-include GIT-VERSION-FILE
 
 check-warnings:
 	@(for i in $$(git ls-files '*.rb'| grep -v '^setup\.rb$$'); \
diff --git a/lib/olddoc.rb b/lib/olddoc.rb
index 5a70577..3061e73 100644
--- a/lib/olddoc.rb
+++ b/lib/olddoc.rb
@@ -1,8 +1,6 @@
 # Copyright (C) 2015-2016 all contributors <olddoc-public@80x24.org>
 # License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
 module Olddoc # :nodoc:
-  VERSION = '1.2.0' # :nodoc:
-
   autoload :Gemspec, 'olddoc/gemspec'
   autoload :History, 'olddoc/history'
   autoload :Merge, 'olddoc/merge'
diff --git a/olddoc.gemspec b/olddoc.gemspec
index def2265..d059955 100644
--- a/olddoc.gemspec
+++ b/olddoc.gemspec
@@ -2,6 +2,7 @@
 # License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
 $LOAD_PATH << 'lib'
 require 'olddoc'
+require 'olddoc/version'
 extend Olddoc::Gemspec
 name, summary, title = readme_metadata
 Gem::Specification.new do |s|
-- 
EW