python: Adds instructions to the manifest file

While there is a bit of documentation regarding building a new
manifest file for python, it seems that users usually only read
the manifest file.

The manifest file is in JSON format which doesn't allow comments,
hence why instructions were initially put elsewhere.

This patch hacks the call to open the JSON manifest file by using a
marker to trick it into reading only part of the file as the manifest
itself, and keep the other part as comments, which contain instructions
for the user to run the create_manifest task after an upgrade or
when adding a new package.

(From OE-Core rev: 5641a24a70b54544012c04c6a082514d9a5aa49a)

(From OE-Core rev: 3050a4c634da74eba53380bf23de515ed651bc03)

Signed-off-by: Alejandro Enedino Hernandez Samaniego <alejandr@xilinx.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 17 insertions, 4 deletions

diff --git a/meta/recipes-devtools/python/python/create_manifest2.py b/meta/recipes-devtools/python/python/create_manifest2.py
index 87999991d7..b6748653b6 100644
--- a/meta/recipes-devtools/python/python/create_manifest2.py
+++ b/meta/recipes-devtools/python/python/create_manifest2.py
@@ -22,7 +22,7 @@
 #
 #
 # This way we will create a new manifest from the data structure that was built during
-# this process, ont this new manifest each package will contain specifically only
+# this process, on this new manifest each package will contain specifically only
 # what it needs to run.
 #
 # There are some caveats which we try to deal with, such as repeated files on different
@@ -30,7 +30,7 @@
 # Its also important to note that this method only works for python files, and shared
 # libraries. Static libraries, header files and binaries need to be dealt with manually.
 #
-# Author: Alejandro Enedino Hernandez Samaniego "aehs29" <aehs29@gmail.com>
+# Author: Alejandro Enedino Hernandez Samaniego "aehs29" <aehs29 at gmail dot com>
 
 
 import sys
@@ -62,10 +62,21 @@ def isFolder(value):
   else:
     return False
 
+def prepend_comments(comments, json_manifest):
+    with open(json_manifest, 'r+') as manifest:
+        json_contents = manifest.read()
+        manifest.seek(0, 0)
+        manifest.write(comments + json_contents)
+
 # Read existing JSON manifest
 with open('python2-manifest.json') as manifest:
-  old_manifest = json.load(manifest, object_pairs_hook=collections.OrderedDict)
-
+    # The JSON format doesn't allow comments so we hack the call to keep the comments using a marker
+    manifest_str =  manifest.read()
+    json_start = manifest_str.find('# EOC') + 6 # EOC + \n
+    manifest.seek(0)
+    comments = manifest.read(json_start)
+    manifest_str = manifest.read()
+    old_manifest = json.loads(manifest_str, object_pairs_hook=collections.OrderedDict)
 
 # First pass to get core-package functionality, because we base everything on the fact that core is actually working
 # Not exactly the same so it should not be a function
@@ -277,3 +288,5 @@ for key in new_manifest:
 # Create the manifest from the data structure that was built
 with open('python2-manifest.json.new','w') as outfile:
     json.dump(new_manifest,outfile, indent=4)
+
+prepend_comments(comments,'python2-manifest.json.new')