Add $GIT_VERSION to the spec which is replaced by the gendoc script.

scripts/gendoc.py

@@ -1,21 +1,82 @@
 #! /usr/bin/env python
 
 from docutils.core import publish_file
+import fileinput
 import glob
 import os
 import shutil
+import subprocess
 import sys
 
 stylesheets = {
     "stylesheet_path": ["basic.css", "nature.css"]
 }
 
+
+def get_git_ver_string():
+    null = open(os.devnull, 'w')
+    cwd = os.path.dirname(os.path.abspath(__file__))
+    try:
+        git_branch = subprocess.check_output(
+            ['git', 'rev-parse', '--abbrev-ref', 'HEAD'],
+            stderr=null,
+            cwd=cwd,
+        ).strip()
+    except subprocess.CalledProcessError:
+        git_branch = ""
+    try:
+        git_tag = subprocess.check_output(
+            ['git', 'describe', '--exact-match'],
+            stderr=null,
+            cwd=cwd,
+        ).strip()
+        git_tag = "tag=" + git_tag
+    except subprocess.CalledProcessError:
+        git_tag = ""
+    try:
+        git_commit = subprocess.check_output(
+            ['git', 'rev-parse', '--short', 'HEAD'],
+            stderr=null,
+            cwd=cwd,
+        ).strip()
+    except subprocess.CalledProcessError:
+        git_commit = ""
+    try:
+        dirty_string = "-this_is_a_dirty_checkout"
+        is_dirty = subprocess.check_output(
+            ['git', 'describe', '--dirty=' + dirty_string, "--all"],
+            stderr=null,
+            cwd=cwd,
+        ).strip().endswith(dirty_string)
+        git_dirty = "dirty" if is_dirty else ""
+    except subprocess.CalledProcessError:
+        git_dirty = ""
+
+    if git_branch or git_tag or git_commit or git_dirty:
+        git_version = ",".join(
+            s for s in
+            (git_branch, git_tag, git_commit, git_dirty,)
+            if s
+        )
+        return git_version.encode("ascii")
+    return "Unknown rev"
+
+
 def glob_spec(out_file_name):
     with open(out_file_name, "wb") as outfile:
         for f in sorted(glob.glob("../specification/*.rst")):
             with open(f, "rb") as infile:
                 outfile.write(infile.read())
 
+def set_git_version(filename):
+    git_ver = get_git_ver_string()
+    # inplace search and replace, stdout is redirected to the output
+    # file, hence the "print" lines here.
+    for line in fileinput.input(filename, inplace=True):
+        if "$GIT_VERSION" in line:
+            line = line.replace("$GIT_VERSION", git_ver)
+        print line.rstrip("\n")
+    
 
 def rst2html(i, o):
     with open(i, "r") as in_file:
@@ -45,6 +106,7 @@ def cleanup_env():
 def main():
     prepare_env()
     glob_spec("tmp/full_spec.rst")
+    set_git_version("tmp/full_spec.rst")
     rst2html("tmp/full_spec.rst", "gen/specification.html")
     rst2html("../howtos/client-server.rst", "gen/howtos.html")
     cleanup_env()

specification/00_basis.rst

@@ -1,5 +1,6 @@
 Matrix Specification
 ====================
+$GIT_VERSION
 
 Table of Contents
 =================
@@ -85,7 +86,7 @@ Version
 =======
 
 The Matrix spec is currently rapidly evolving, and there have been no versioned
-releases as yet.  Versions should be identified by git revision, or failing that
+releases as yet. Versions should be identified by git revision, or failing that
 timestamp.
 
 Overview