Rather than fill our text files with :c:func:`function()` syntax, just do
the markup via a hook into the sphinx build process.
Signed-off-by: Jonathan Corbet <corbet@xxxxxxx>
---
Documentation/conf.py | 3 +-
Documentation/sphinx/automarkup.py | 93 ++++++++++++++++++++++++++++++
2 files changed, 95 insertions(+), 1 deletion(-)
create mode 100644 Documentation/sphinx/automarkup.py
diff --git a/Documentation/conf.py b/Documentation/conf.py
index 7ace3f8852bd..a502baecbb85 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -34,7 +34,8 @@ needs_sphinx = '1.3'
# Add any Sphinx extension module names here, as strings. They can be
# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
# ones.
-extensions = ['kerneldoc', 'rstFlatTable', 'kernel_include', 'cdomain', 'kfigure', 'sphinx.ext.ifconfig']
+extensions = ['kerneldoc', 'rstFlatTable', 'kernel_include', 'cdomain',
+ 'kfigure', 'sphinx.ext.ifconfig', 'automarkup']
# The name of the math extension changed on Sphinx 1.4
if (major == 1 and minor > 3) or (major > 1):
diff --git a/Documentation/sphinx/automarkup.py b/Documentation/sphinx/automarkup.py
new file mode 100644
index 000000000000..b300cf129869
--- /dev/null
+++ b/Documentation/sphinx/automarkup.py
@@ -0,0 +1,93 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2019 Jonathan Corbet <corbet@xxxxxxx>
+#
+# Apply kernel-specific tweaks after the initial document processing
+# has been done.
+#
+from docutils import nodes
+from sphinx import addnodes
+import re
+
+#
+# Regex nastiness. Of course.
+# Try to identify "function()" that's not already marked up some
+# other way. Sphinx doesn't like a lot of stuff right after a
+# :c:func: block (i.e. ":c:func:`mmap()`s" flakes out), so the last
+# bit tries to restrict matches to things that won't create trouble.
+#
+RE_function = re.compile(r'([\w_][\w\d_]+\(\))')
+
+#
+# Many places in the docs refer to common system calls. It is
+# pointless to try to cross-reference them and, as has been known
+# to happen, somebody defining a function by these names can lead
+# to the creation of incorrect and confusing cross references. So
+# just don't even try with these names.
+#
+Skipfuncs = [ 'open', 'close', 'read', 'write', 'fcntl', 'mmap'
+ 'select', 'poll', 'fork', 'execve', 'clone', 'ioctl']
+
+#
+# Find all occurrences of function() and try to replace them with
+# appropriate cross references.
+#
+def markup_funcs(docname, app, node):
+ cdom = app.env.domains['c']
+ t = node.astext()
+ done = 0
+ repl = [ ]
+ for m in RE_function.finditer(t):
+ #
+ # Include any text prior to function() as a normal text node.
+ #
+ if m.start() > done:
+ repl.append(nodes.Text(t[done:m.start()]))
+ #
+ # Go through the dance of getting an xref out of the C domain
+ #
+ target = m.group(1)[:-2]
+ target_text = nodes.Text(target + '()')
+ xref = None
+ if target not in Skipfuncs:
+ lit_text = nodes.literal(classes=['xref', 'c', 'c-func'])
+ lit_text += target_text
+ pxref = addnodes.pending_xref('', refdomain = 'c',
+ reftype = 'function',
+ reftarget = target, modname = None,
+ classname = None)
+ xref = cdom.resolve_xref(app.env, docname, app.builder,
+ 'function', target, pxref, lit_text)
+ #
+ # Toss the xref into the list if we got it; otherwise just put
+ # the function text.
+ #
+ if xref:
+ repl.append(xref)
+ else:
+ repl.append(target_text)
+ done = m.end()
+ if done < len(t):
+ repl.append(nodes.Text(t[done:]))
+ return repl
+
+def auto_markup(app, doctree, name):
+ #
+ # This loop could eventually be improved on. Someday maybe we
+ # want a proper tree traversal with a lot of awareness of which
+ # kinds of nodes to prune. But this works well for now.
+ #
+ # The nodes.literal test catches ``literal text``, its purpose is to
+ # avoid adding cross-references to functions that have been explicitly
+ # marked with cc:func:.
+ #
+ for para in doctree.traverse(nodes.paragraph):
+ for node in para.traverse(nodes.Text):
+ if not isinstance(node.parent, nodes.literal):
+ node.parent.replace(node, markup_funcs(name, app, node))
+
+def setup(app):
+ app.connect('doctree-resolved', auto_markup)
+ return {
+ 'parallel_read_safe': True,
+ 'parallel_write_safe': True,
+ }
--
2.21.0
