docs: Refactor extensions into packages, update the add-ons-reference docs page

Includes converting some of the remaining standalone scripts into Sphinx extensions.

Make flake8 clean

docs/idf_extensions/util.py

@@ -0,0 +1,80 @@
+# Utility functions used in conf.py
+#
+# Copyright 2017 Espressif Systems (Shanghai) PTE LTD
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http:#www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import unicode_literals
+from io import open
+import os
+import shutil
+import sys
+
+try:
+    import urllib.request
+    _urlretrieve = urllib.request.urlretrieve
+except ImportError:
+    # Python 2 fallback
+    import urllib
+    _urlretrieve = urllib.urlretrieve
+
+
+def files_equal(path_1, path_2):
+    if not os.path.exists(path_1) or not os.path.exists(path_2):
+        return False
+    file_1_contents = ''
+    with open(path_1, "r", encoding='utf-8') as f_1:
+        file_1_contents = f_1.read()
+    file_2_contents = ''
+    with open(path_2, "r", encoding='utf-8') as f_2:
+        file_2_contents = f_2.read()
+    return file_1_contents == file_2_contents
+
+
+def copy_file_if_modified(src_file_path, dst_file_path):
+    if not files_equal(src_file_path, dst_file_path):
+        dst_dir_name = os.path.dirname(dst_file_path)
+        if not os.path.isdir(dst_dir_name):
+            os.makedirs(dst_dir_name)
+        shutil.copy(src_file_path, dst_file_path)
+
+
+def copy_if_modified(src_path, dst_path):
+    if os.path.isfile(src_path):
+        copy_file_if_modified(src_path, dst_path)
+        return
+
+    src_path_len = len(src_path)
+    for root, dirs, files in os.walk(src_path):
+        for src_file_name in files:
+            src_file_path = os.path.join(root, src_file_name)
+            dst_file_path = os.path.join(dst_path + root[src_path_len:], src_file_name)
+            copy_file_if_modified(src_file_path, dst_file_path)
+
+
+def download_file_if_missing(from_url, to_path):
+    filename_with_path = to_path + "/" + os.path.basename(from_url)
+    exists = os.path.isfile(filename_with_path)
+    if exists:
+        print("The file '%s' already exists" % (filename_with_path))
+    else:
+        tmp_file, header = _urlretrieve(from_url)
+        with open(filename_with_path, 'wb') as fobj:
+            with open(tmp_file, 'rb') as tmp:
+                fobj.write(tmp.read())
+
+
+def call_with_python(cmd):
+    # using sys.executable ensures that the scripts are called with the same Python interpreter
+    if os.system('{} {}'.format(sys.executable, cmd)) != 0:
+        raise RuntimeError('{} failed'.format(cmd))