| # 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\-_/]+)(\.\w+)*') | |
| 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 | |
| # | |
| # 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): | |
| class_str = ['c-func', 'c-macro'] | |
| reftype_str = ['function', 'macro'] | |
| 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: | |
| for class_s, reftype_s in zip(class_str, reftype_str): | |
| lit_text = nodes.literal(classes=['xref', 'c', class_s]) | |
| lit_text += target_text | |
| pxref = addnodes.pending_xref('', refdomain = 'c', | |
| reftype = reftype_s, | |
| 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_s, target, pxref, | |
| lit_text) | |
| except NoUri: | |
| xref = None | |
| if xref: | |
| return xref | |
| 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 | |
| # | |
| target = match.group(1) | |
| 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) | |
| # | |
| # 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_refs(name, app, node)) | |
| def setup(app): | |
| app.connect('doctree-resolved', auto_markup) | |
| return { | |
| 'parallel_read_safe': True, | |
| 'parallel_write_safe': True, | |
| } |