bitbake: doc: add a new Library Functions document

Add a new document to the BitBake user manual that automatically
documents the library functions from their docstrings. The docstrings
can be formatted in reStructuredText.

Here logging utilities and the bb.utils module is documented. Some
members of the utils module were deliberately excluded as their usage is
most likely only internal to BitBake.

Fixes [YOCTO #9612]

(Bitbake rev: 0a711949acc2696f32a61c591ee3ea37041acb91)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/doc/conf.py

@@ -17,6 +17,8 @@
 import sys
 import datetime
 
+from pathlib import Path
+
 current_version = "dev"
 
 # String used in sidebar
@@ -47,6 +49,7 @@ extlinks = {
 extensions = [
     'sphinx.ext.autosectionlabel',
     'sphinx.ext.extlinks',
+    'sphinx.ext.autodoc',
 ]
 autosectionlabel_prefix_document = True
 
@@ -99,3 +102,7 @@ html_last_updated_fmt = '%b %d, %Y'
 
 # Remove the trailing 'dot' in section numbers
 html_secnumber_suffix = " "
+
+# autoconf needs the modules available to auto-generate documentation from the
+# code
+sys.path.insert(0, str(Path('..', 'lib').resolve()))