Revert "doc: update Kernel documentation build system"

Unfortunately we now see a number of now-fatal warnings about duplicate
labels.  It is often unclear how best to re-write the document in
question to not duplicate these otherwise logical headings.

This reverts commit 10a1df3cd4.

Signed-off-by: Tom Rini <trini@konsulko.com>

doc/sphinx/cdomain.py

@@ -40,94 +40,14 @@ from sphinx import addnodes
 from sphinx.domains.c import c_funcptr_sig_re, c_sig_re
 from sphinx.domains.c import CObject as Base_CObject
 from sphinx.domains.c import CDomain as Base_CDomain
-from itertools import chain
-import re
 
-__version__  = '1.1'
+__version__  = '1.0'
 
 # Get Sphinx version
 major, minor, patch = sphinx.version_info[:3]
 
-# Namespace to be prepended to the full name
-namespace = None
-
-#
-# Handle trivial newer c domain tags that are part of Sphinx 3.1 c domain tags
-# - Store the namespace if ".. c:namespace::" tag is found
-#
-RE_namespace = re.compile(r'^\s*..\s*c:namespace::\s*(\S+)\s*$')
-
-def markup_namespace(match):
-    global namespace
-
-    namespace = match.group(1)
-
-    return ""
-
-#
-# Handle c:macro for function-style declaration
-#
-RE_macro = re.compile(r'^\s*..\s*c:macro::\s*(\S+)\s+(\S.*)\s*$')
-def markup_macro(match):
-    return ".. c:function:: " + match.group(1) + ' ' + match.group(2)
-
-#
-# Handle newer c domain tags that are evaluated as .. c:type: for
-# backward-compatibility with Sphinx < 3.0
-#
-RE_ctype = re.compile(r'^\s*..\s*c:(struct|union|enum|enumerator|alias)::\s*(.*)$')
-
-def markup_ctype(match):
-    return ".. c:type:: " + match.group(2)
-
-#
-# Handle newer c domain tags that are evaluated as :c:type: for
-# backward-compatibility with Sphinx < 3.0
-#
-RE_ctype_refs = re.compile(r':c:(var|struct|union|enum|enumerator)::`([^\`]+)`')
-def markup_ctype_refs(match):
-    return ":c:type:`" + match.group(2) + '`'
-
-#
-# Simply convert :c:expr: and :c:texpr: into a literal block.
-#
-RE_expr = re.compile(r':c:(expr|texpr):`([^\`]+)`')
-def markup_c_expr(match):
-    return '\ ``' + match.group(2) + '``\ '
-
-#
-# Parse Sphinx 3.x C markups, replacing them by backward-compatible ones
-#
-def c_markups(app, docname, source):
-    result = ""
-    markup_func = {
-        RE_namespace: markup_namespace,
-        RE_expr: markup_c_expr,
-        RE_macro: markup_macro,
-        RE_ctype: markup_ctype,
-        RE_ctype_refs: markup_ctype_refs,
-    }
-
-    lines = iter(source[0].splitlines(True))
-    for n in lines:
-        match_iterators = [regex.finditer(n) for regex in markup_func]
-        matches = sorted(chain(*match_iterators), key=lambda m: m.start())
-        for m in matches:
-            n = n[:m.start()] + markup_func[m.re](m) + n[m.end():]
-
-        result = result + n
-
-    source[0] = result
-
-#
-# Now implements support for the cdomain namespacing logic
-#
-
 def setup(app):
 
-    # Handle easy Sphinx 3.1+ simple new tags: :c:expr and .. c:namespace::
-    app.connect('source-read', c_markups)
-
     if (major == 1 and minor < 8):
         app.override_domain(CDomain)
     else:
@@ -155,8 +75,6 @@ class CObject(Base_CObject):
         function-like macro, the name of the macro is returned. Otherwise
         ``False`` is returned.  """
 
-        global namespace
-
         if not self.objtype == 'function':
             return False
 
@@ -189,16 +107,11 @@ class CObject(Base_CObject):
             param += nodes.emphasis(argname, argname)
             paramlist += param
 
-        if namespace:
-            fullname = namespace + "." + fullname
-
         return fullname
 
     def handle_signature(self, sig, signode):
         """Transform a C signature into RST nodes."""
 
-        global namespace
-
         fullname = self.handle_func_like_macro(sig, signode)
         if not fullname:
             fullname = super(CObject, self).handle_signature(sig, signode)
@@ -209,10 +122,6 @@ class CObject(Base_CObject):
             else:
                 # FIXME: handle :name: value of other declaration types?
                 pass
-        else:
-            if namespace:
-                fullname = namespace + "." + fullname
-
         return fullname
 
     def add_target_and_index(self, name, sig, signode):