docs: Make Python 3 compatible

docs/build_docs.py

@@ -188,9 +188,9 @@ def sphinx_call(language, target, build_dir, sphinx_parallel_jobs, buildername):
         # and sphinx.cmd.build() also does a lot of work in the calling thread, especially for j ==1,
         # so using a Pyhthon thread for this part is  a poor option (GIL)
         p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-        for c in iter(lambda: p.stdout.readline(), ''):
+        for c in iter(lambda: p.stdout.readline(), b''):
             sys.stdout.write(prefix)
-            sys.stdout.write(c)
+            sys.stdout.write(c.decode('utf-8'))
         ret = p.wait()
         assert (ret is not None)
         sys.stdout.flush()

docs/idf_extensions/esp_err_definitions.py

@@ -1,5 +1,5 @@
 # Extension to generate esp_err definition as .rst
-from util import copy_if_modified, call_with_python
+from .util import copy_if_modified, call_with_python
 
 
 def setup(app):

docs/idf_extensions/gen_toolchain_links.py

@@ -2,7 +2,7 @@
 from __future__ import print_function
 import os.path
 from collections import namedtuple
-from util import copy_if_modified
+from .util import copy_if_modified
 
 BASE_URL = 'https://dl.espressif.com/dl/'
 

docs/idf_extensions/gen_version_specific_includes.py

@@ -7,7 +7,7 @@
 from __future__ import print_function
 from __future__ import unicode_literals
 from io import open
-from util import copy_if_modified
+from .util import copy_if_modified
 import subprocess
 import os
 import re

docs/idf_extensions/kconfig_reference.py

@@ -3,7 +3,7 @@ import os.path
 import sys
 import subprocess
 
-from util import copy_if_modified
+from .util import copy_if_modified
 
 
 def setup(app):

docs/idf_extensions/run_doxygen.py

@@ -7,7 +7,7 @@ import os
 import os.path
 import re
 import subprocess
-from util import copy_if_modified
+from .util import copy_if_modified
 
 ALL_KINDS = [
     ("function", "Functions"),