| # SPDX-License-Identifier: GPL-2.0 |
| # Copyright 2019 Jonathan Corbet <corbet@lwn.net> |
| # |
| # Apply kernel-specific tweaks after the initial document processing |
| # has been done. |
| # |
| from docutils import nodes |
| import sphinx |
| from sphinx import addnodes |
| if sphinx.version_info[0] < 2 or \ |
| sphinx.version_info[0] == 2 and sphinx.version_info[1] < 1: |
| from sphinx.environment import NoUri |
| else: |
| from sphinx.errors import NoUri |
| import re |
| from itertools import chain |
| |
| # |
| # Python 2 lacks re.ASCII... |
| # |
| try: |
| ascii_p3 = re.ASCII |
| except AttributeError: |
| ascii_p3 = 0 |
| |
| # |
| # 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'\b(([a-zA-Z_]\w+)\(\))', flags=ascii_p3) |
| |
| # |
| # Sphinx 2 uses the same :c:type role for struct, union, enum and typedef |
| # |
| RE_generic_type = re.compile(r'\b(struct|union|enum|typedef)\s+([a-zA-Z_]\w+)', |
| flags=ascii_p3) |
| |
| # |
| # Sphinx 3 uses a different C role for each one of struct, union, enum and |
| # typedef |
| # |
| RE_struct = re.compile(r'\b(struct)\s+([a-zA-Z_]\w+)', flags=ascii_p3) |
| RE_union = re.compile(r'\b(union)\s+([a-zA-Z_]\w+)', flags=ascii_p3) |
| RE_enum = re.compile(r'\b(enum)\s+([a-zA-Z_]\w+)', flags=ascii_p3) |
| RE_typedef = re.compile(r'\b(typedef)\s+([a-zA-Z_]\w+)', flags=ascii_p3) |
| |
| # |
| # Detects a reference to a documentation page of the form Documentation/... with |
| # an optional extension |
| # |
| RE_doc = re.compile(r'(\bDocumentation/)?((\.\./)*[\w\-/]+)\.(rst|txt)') |
| |
| RE_namespace = re.compile(r'^\s*..\s*c:namespace::\s*(\S+)\s*$') |
| |
| # |
| # Reserved C words that we should skip when cross-referencing |
| # |
| Skipnames = [ 'for', 'if', 'register', 'sizeof', 'struct', 'unsigned' ] |
| |
| |
| # |
| # 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', |
| 'socket' ] |
| |
| c_namespace = '' |
| |
| def markup_refs(docname, app, node): |
| t = node.astext() |
| done = 0 |
| repl = [ ] |
| # |
| # Associate each regex with the function that will markup its matches |
| # |
| markup_func_sphinx2 = {RE_doc: markup_doc_ref, |
| RE_function: markup_c_ref, |
| RE_generic_type: markup_c_ref} |
| |
| markup_func_sphinx3 = {RE_doc: markup_doc_ref, |
| RE_function: markup_func_ref_sphinx3, |
| RE_struct: markup_c_ref, |
| RE_union: markup_c_ref, |
| RE_enum: markup_c_ref, |
| RE_typedef: markup_c_ref} |
| |
| if sphinx.version_info[0] >= 3: |
| markup_func = markup_func_sphinx3 |
| else: |
| markup_func = markup_func_sphinx2 |
| |
| match_iterators = [regex.finditer(t) for regex in markup_func] |
| # |
| # Sort all references by the starting position in text |
| # |
| sorted_matches = sorted(chain(*match_iterators), key=lambda m: m.start()) |
| for m in sorted_matches: |
| # |
| # Include any text prior to match as a normal text node. |
| # |
| if m.start() > done: |
| repl.append(nodes.Text(t[done:m.start()])) |
| |
| # |
| # Call the function associated with the regex that matched this text and |
| # append its return to the text |
| # |
| repl.append(markup_func[m.re](docname, app, m)) |
| |
| done = m.end() |
| if done < len(t): |
| repl.append(nodes.Text(t[done:])) |
| return repl |
| |
| # |
| # Keep track of cross-reference lookups that failed so we don't have to |
| # do them again. |
| # |
| failed_lookups = { } |
| def failure_seen(target): |
| return (target) in failed_lookups |
| def note_failure(target): |
| failed_lookups[target] = True |
| |
| # |
| # In sphinx3 we can cross-reference to C macro and function, each one with its |
| # own C role, but both match the same regex, so we try both. |
| # |
| def markup_func_ref_sphinx3(docname, app, match): |
| cdom = app.env.domains['c'] |
| # |
| # Go through the dance of getting an xref out of the C domain |
| # |
| base_target = match.group(2) |
| target_text = nodes.Text(match.group(0)) |
| xref = None |
| possible_targets = [base_target] |
| # Check if this document has a namespace, and if so, try |
| # cross-referencing inside it first. |
| if c_namespace: |
| possible_targets.insert(0, c_namespace + "." + base_target) |
| |
| if base_target not in Skipnames: |
| for target in possible_targets: |
| if (target not in Skipfuncs) and not failure_seen(target): |
| 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) |
| # |
| # XXX The Latex builder will throw NoUri exceptions here, |
| # work around that by ignoring them. |
| # |
| try: |
| xref = cdom.resolve_xref(app.env, docname, app.builder, |
| 'function', target, pxref, |
| lit_text) |
| except NoUri: |
| xref = None |
| |
| if xref: |
| return xref |
| note_failure(target) |
| |
| return target_text |
| |
| def markup_c_ref(docname, app, match): |
| class_str = {# Sphinx 2 only |
| RE_function: 'c-func', |
| RE_generic_type: 'c-type', |
| # Sphinx 3+ only |
| RE_struct: 'c-struct', |
| RE_union: 'c-union', |
| RE_enum: 'c-enum', |
| RE_typedef: 'c-type', |
| } |
| reftype_str = {# Sphinx 2 only |
| RE_function: 'function', |
| RE_generic_type: 'type', |
| # Sphinx 3+ only |
| RE_struct: 'struct', |
| RE_union: 'union', |
| RE_enum: 'enum', |
| RE_typedef: 'type', |
| } |
| |
| cdom = app.env.domains['c'] |
| # |
| # Go through the dance of getting an xref out of the C domain |
| # |
| base_target = match.group(2) |
| target_text = nodes.Text(match.group(0)) |
| xref = None |
| possible_targets = [base_target] |
| # Check if this document has a namespace, and if so, try |
| # cross-referencing inside it first. |
| if c_namespace: |
| possible_targets.insert(0, c_namespace + "." + base_target) |
| |
| if base_target not in Skipnames: |
| for target in possible_targets: |
| if not (match.re == RE_function and target in Skipfuncs): |
| lit_text = nodes.literal(classes=['xref', 'c', class_str[match.re]]) |
| lit_text += target_text |
| pxref = addnodes.pending_xref('', refdomain = 'c', |
| reftype = reftype_str[match.re], |
| reftarget = target, modname = None, |
| classname = None) |
| # |
| # XXX The Latex builder will throw NoUri exceptions here, |
| # work around that by ignoring them. |
| # |
| try: |
| xref = cdom.resolve_xref(app.env, docname, app.builder, |
| reftype_str[match.re], target, pxref, |
| lit_text) |
| except NoUri: |
| xref = None |
| |
| if xref: |
| return xref |
| |
| return target_text |
| |
| # |
| # Try to replace a documentation reference of the form Documentation/... with a |
| # cross reference to that page |
| # |
| def markup_doc_ref(docname, app, match): |
| stddom = app.env.domains['std'] |
| # |
| # Go through the dance of getting an xref out of the std domain |
| # |
| absolute = match.group(1) |
| target = match.group(2) |
| if absolute: |
| target = "/" + target |
| xref = None |
| pxref = addnodes.pending_xref('', refdomain = 'std', reftype = 'doc', |
| reftarget = target, modname = None, |
| classname = None, refexplicit = False) |
| # |
| # XXX The Latex builder will throw NoUri exceptions here, |
| # work around that by ignoring them. |
| # |
| try: |
| xref = stddom.resolve_xref(app.env, docname, app.builder, 'doc', |
| target, pxref, None) |
| except NoUri: |
| xref = None |
| # |
| # Return the xref if we got it; otherwise just return the plain text. |
| # |
| if xref: |
| return xref |
| else: |
| return nodes.Text(match.group(0)) |
| |
| def get_c_namespace(app, docname): |
| source = app.env.doc2path(docname) |
| with open(source) as f: |
| for l in f: |
| match = RE_namespace.search(l) |
| if match: |
| return match.group(1) |
| return '' |
| |
| def auto_markup(app, doctree, name): |
| global c_namespace |
| c_namespace = get_c_namespace(app, name) |
| def text_but_not_a_reference(node): |
| # 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:. |
| if not isinstance(node, nodes.Text) or isinstance(node.parent, nodes.literal): |
| return False |
| |
| child_of_reference = False |
| parent = node.parent |
| while parent: |
| if isinstance(parent, nodes.Referential): |
| child_of_reference = True |
| break |
| parent = parent.parent |
| return not child_of_reference |
| |
| # |
| # 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. |
| # |
| for para in doctree.traverse(nodes.paragraph): |
| for node in para.traverse(condition=text_but_not_a_reference): |
| node.parent.replace(node, markup_refs(name, app, node)) |
| |
| def setup(app): |
| app.connect('doctree-resolved', auto_markup) |
| return { |
| 'parallel_read_safe': True, |
| 'parallel_write_safe': True, |
| } |
