Re: [PATCH v2] docs: automarkup.py: Allow automatic cross-reference inside C namespace

From: Mauro Carvalho Chehab
Date: Tue Nov 17 2020 - 00:48:09 EST


Em Tue, 17 Nov 2020 02:12:01 +0000
Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxxx> escreveu:

> Sphinx 3.1 introduced namespaces for C cross-references. With this,
> each C domain type/function declaration is put inside the namespace that
> was active at the time of its declaration.
>
> Add support for automatic cross-referencing inside C namespaces by
> checking whether the corresponding source file had a C namespace Sphinx
> directive, and if so, try cross-referencing inside of it before going to
> the global scope.
>
> This assumes there's only one namespace (if any) per rst file.
>
> Signed-off-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxxx>
> ---
>
> To those following from v1:
>
> I ended up doing the simplest solution possible, which is to just directly read
> the rst source corresponding to the doc page right before doing the automarkup.
> It's not very efficient in the sense that the source is being read
> twice (first by Sphinx, then by this), but it sidesteps the "data sharing
> between processes" issue, so parallel_read_safe can be reenabled, and I didn't
> notice any performance hit from this patch (as opposed to the big hit from v1).
> Works with both Sphinx 2 and 3.
>
> Changes in v2:
> - Get C namespace from reading the corresponding source at the time of doing
> automarkup instead of storing all namespaces beforehand at the source-read
> phase
> - Add get_c_namespace()
> - Remove save_c_namespace()
> - Reenabled Sphinx's parallel_read_safe
>
> v1: https://lore.kernel.org/linux-doc/20201013231218.2750109-6-nfraprado@xxxxxxxxxxxxxx/
>
> Documentation/sphinx/automarkup.py | 122 ++++++++++++++++++-----------
> 1 file changed, 75 insertions(+), 47 deletions(-)
>
> diff --git a/Documentation/sphinx/automarkup.py b/Documentation/sphinx/automarkup.py
> index 3e81ebab26ed..953b24b6e2b4 100644
> --- a/Documentation/sphinx/automarkup.py
> +++ b/Documentation/sphinx/automarkup.py
> @@ -53,6 +53,8 @@ RE_typedef = re.compile(r'\b(typedef)\s+([a-zA-Z_]\w+)', flags=ascii_p3)
> #
> 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
> #
> @@ -70,6 +72,8 @@ 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
> @@ -128,30 +132,38 @@ def markup_func_ref_sphinx3(docname, app, match):
> #
> # Go through the dance of getting an xref out of the C domain
> #
> - target = match.group(2)
> + base_target = match.group(2)
> target_text = nodes.Text(match.group(0))
> xref = None
> - if not (target in Skipfuncs or target in Skipnames):
> - 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
> + 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 xref:
> - return xref
> + if base_target not in Skipnames:
> + for target in possible_targets:
> + if target not in Skipfuncs:

Hmm... do we still need to skip syscalls?

> + 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
>
> @@ -179,34 +191,39 @@ def markup_c_ref(docname, app, match):
> #
> # Go through the dance of getting an xref out of the C domain
> #
> - target = match.group(2)
> + base_target = match.group(2)
> target_text = nodes.Text(match.group(0))
> xref = None
> - if not ((match.re == RE_function and target in Skipfuncs)
> - or (target in Skipnames)):
> - 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
> - #
> - # Return the xref if we got it; otherwise just return the plain text.
> - #
> - if xref:
> - return xref
> - else:
> - return target_text
> + 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
> @@ -239,7 +256,18 @@ def markup_doc_ref(docname, app, match):
> 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



Thanks,
Mauro