[lldb] Cleanup Python API reference files after building the docs

The sphinx-automodapi extension requires that the generated RST files
live next to the index file. This means that we generate them in the
source directory rather than the build directory. This patch ensures
these files are removed again when sphinx finishes its build.

The proper solution to this problem would be to move everything in the
doc folder from the source directory to the build directory before
generating the docs.

I believe that old RST files being kept around is the reason that the
Python API references on the website isn't getting updated. This patch
is meant as a speculative fix and a way to confirm that.

Author: JDevlieghere

lldb/docs/conf.py

@@ -12,7 +12,7 @@
 # serve to show the default.
 from __future__ import print_function
 
-import sys, os, re
+import sys, os, re, shutil
 from datetime import date
 
 building_man_page = tags.has('builder-man')
@@ -293,8 +293,8 @@
 empty_attr_summary = re.compile(r'\.\. rubric:: Attributes Summary\s*\.\. autosummary::\s*\.\. rubric::')
 empty_attr_documentation = re.compile(r'\.\. rubric:: Attributes Documentation\s*\.\. rubric::')
 
-def cleanup_source(app, docname, source):
-    """ Cleans up source files generated by automodapi. """
+def preprocess_source(app, docname, source):
+    """ Preprocesses source files generated by automodapi. """
     # Don't cleanup anything beside automodapi-generated sources.
     if not automodapi_toctreedirnm in docname:
       return
@@ -320,5 +320,12 @@ def cleanup_source(app, docname, source):
     # element list).
     source[0] = processed
 
+def cleanup_source(app, exception):
+    """ Remove files generated by automodapi in the source tree. """
+    if hasattr(app.config, 'automodapi_toctreedirnm'):
+      api_source_dir = os.path.join(app.srcdir, app.config.automodapi_toctreedirnm)
+      shutil.rmtree(api_source_dir, ignore_errors=True)
+
 def setup(app):
-    app.connect('source-read', cleanup_source)
+    app.connect('source-read', preprocess_source)
+    app.connect('build-finished', cleanup_source)