[PATCH v6 10/21] tools/docs: sphinx-build-wrapper: add a wrapper for sphinx-build

Mauro Carvalho Chehab posted 21 patches 2 weeks, 2 days ago
There is a newer version of this series
[PATCH v6 10/21] tools/docs: sphinx-build-wrapper: add a wrapper for sphinx-build
Posted by Mauro Carvalho Chehab 2 weeks, 2 days ago
There are too much magic inside docs Makefile to properly run
sphinx-build. Create an ancillary script that contains all
kernel-related sphinx-build call logic currently at Makefile.

Such script is designed to work both as an standalone command
and as part of a Makefile. As such, it properly handles POSIX
jobserver used by GNU make.

On a side note, there was a line number increase due to the
conversion (ignoring comments) is:

 Documentation/Makefile          |  131 +++----------
 tools/docs/sphinx-build-wrapper |  293 +++++++++++++++++++++++++++++++
 2 files changed, 323 insertions(+), 101 deletions(-)

Comments and descriptions adds:
 tools/docs/sphinx-build-wrapper | 261 +++++++++++++++++++++++++++++++-

So, about half of the script are comments/descriptions.

This is because some things are more verbosed on Python and because
it requires reading env vars from Makefile. Besides it, this script
has some extra features that don't exist at the Makefile:

- It can be called directly from command line;
- It properly return PDF build errors.

When running the script alone, it will only take handle sphinx-build
targets. On other words, it won't runn make rustdoc after building
htmlfiles, nor it will run the extra check scripts.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 Documentation/Makefile          | 131 ++-----
 tools/docs/sphinx-build-wrapper | 581 ++++++++++++++++++++++++++++++++
 2 files changed, 611 insertions(+), 101 deletions(-)
 create mode 100755 tools/docs/sphinx-build-wrapper

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 7570d4cf3b13..4736f02b6c9e 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -23,21 +23,22 @@ SPHINXOPTS    =
 SPHINXDIRS    = .
 DOCS_THEME    =
 DOCS_CSS      =
-_SPHINXDIRS   = $(sort $(patsubst $(srctree)/Documentation/%/index.rst,%,$(wildcard $(srctree)/Documentation/*/index.rst)))
 SPHINX_CONF   = conf.py
 PAPER         =
 BUILDDIR      = $(obj)/output
 PDFLATEX      = xelatex
 LATEXOPTS     = -interaction=batchmode -no-shell-escape
 
+PYTHONPYCACHEPREFIX ?= $(abspath $(BUILDDIR)/__pycache__)
+
+# Wrapper for sphinx-build
+
+BUILD_WRAPPER = $(srctree)/tools/docs/sphinx-build-wrapper
+
 # For denylisting "variable font" files
 # Can be overridden by setting as an env variable
 FONTS_CONF_DENY_VF ?= $(HOME)/deny-vf
 
-ifeq ($(findstring 1, $(KBUILD_VERBOSE)),)
-SPHINXOPTS    += "-q"
-endif
-
 # User-friendly check for sphinx-build
 HAVE_SPHINX := $(shell if which $(SPHINXBUILD) >/dev/null 2>&1; then echo 1; else echo 0; fi)
 
@@ -51,63 +52,31 @@ ifeq ($(HAVE_SPHINX),0)
 
 else # HAVE_SPHINX
 
-# User-friendly check for pdflatex and latexmk
-HAVE_PDFLATEX := $(shell if which $(PDFLATEX) >/dev/null 2>&1; then echo 1; else echo 0; fi)
-HAVE_LATEXMK := $(shell if which latexmk >/dev/null 2>&1; then echo 1; else echo 0; fi)
+# Common documentation targets
+infodocs texinfodocs latexdocs epubdocs xmldocs pdfdocs linkcheckdocs:
+	$(Q)@$(srctree)/tools/docs/sphinx-pre-install --version-check
+	+$(Q)$(PYTHON3) $(BUILD_WRAPPER) $@ \
+		--sphinxdirs="$(SPHINXDIRS)" --conf="$(SPHINX_CONF)" \
+		--builddir="$(BUILDDIR)" \
+		--theme=$(DOCS_THEME) --css=$(DOCS_CSS) --paper=$(PAPER)
 
-ifeq ($(HAVE_LATEXMK),1)
-	PDFLATEX := latexmk -$(PDFLATEX)
-endif #HAVE_LATEXMK
-
-# Internal variables.
-PAPEROPT_a4     = -D latex_elements.papersize=a4paper
-PAPEROPT_letter = -D latex_elements.papersize=letterpaper
-ALLSPHINXOPTS   = -D kerneldoc_srctree=$(srctree) -D kerneldoc_bin=$(KERNELDOC)
-ALLSPHINXOPTS   += $(PAPEROPT_$(PAPER)) $(SPHINXOPTS)
-ifneq ($(wildcard $(srctree)/.config),)
-ifeq ($(CONFIG_RUST),y)
-	# Let Sphinx know we will include rustdoc
-	ALLSPHINXOPTS   +=  -t rustdoc
-endif
+# Special handling for pdfdocs
+ifeq ($(shell which $(PDFLATEX) >/dev/null 2>&1; echo $$?),0)
+pdfdocs: DENY_VF = XDG_CONFIG_HOME=$(FONTS_CONF_DENY_VF)
+else
+pdfdocs:
+	$(warning The '$(PDFLATEX)' command was not found. Make sure you have it installed and in PATH to produce PDF output.)
+	@echo "  SKIP    Sphinx $@ target."
 endif
-# the i18n builder cannot share the environment and doctrees with the others
-I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
-
-# commands; the 'cmd' from scripts/Kbuild.include is not *loopable*
-loop_cmd = $(echo-cmd) $(cmd_$(1)) || exit;
-
-# $2 sphinx builder e.g. "html"
-# $3 name of the build subfolder / e.g. "userspace-api/media", used as:
-#    * dest folder relative to $(BUILDDIR) and
-#    * cache folder relative to $(BUILDDIR)/.doctrees
-# $4 dest subfolder e.g. "man" for man pages at userspace-api/media/man
-# $5 reST source folder relative to $(src),
-#    e.g. "userspace-api/media" for the linux-tv book-set at ./Documentation/userspace-api/media
-
-PYTHONPYCACHEPREFIX ?= $(abspath $(BUILDDIR)/__pycache__)
-
-quiet_cmd_sphinx = SPHINX  $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
-      cmd_sphinx = \
-	PYTHONPYCACHEPREFIX="$(PYTHONPYCACHEPREFIX)" \
-	BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(src)/$5/$(SPHINX_CONF)) \
-	$(PYTHON3) $(srctree)/scripts/jobserver-exec \
-	$(CONFIG_SHELL) $(srctree)/Documentation/sphinx/parallel-wrapper.sh \
-	$(SPHINXBUILD) \
-	-b $2 \
-	-c $(abspath $(src)) \
-	-d $(abspath $(BUILDDIR)/.doctrees/$3) \
-	-D version=$(KERNELVERSION) -D release=$(KERNELRELEASE) \
-	$(ALLSPHINXOPTS) \
-	$(abspath $(src)/$5) \
-	$(abspath $(BUILDDIR)/$3/$4) && \
-	if [ "x$(DOCS_CSS)" != "x" ]; then \
-		cp $(if $(patsubst /%,,$(DOCS_CSS)),$(abspath $(srctree)/$(DOCS_CSS)),$(DOCS_CSS)) $(BUILDDIR)/$3/_static/; \
-	fi
 
+# HTML main logic is identical to other targets. However, if rust is enabled,
+# an extra step at the end is required to generate rustdoc.
 htmldocs:
-	@$(srctree)/tools/docs/sphinx-pre-install --version-check
-	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,html,$(var),,$(var)))
-
+	$(Q)@$(srctree)/tools/docs/sphinx-pre-install --version-check
+	+$(Q)$(PYTHON3) $(BUILD_WRAPPER) $@ \
+		--sphinxdirs="$(SPHINXDIRS)" --conf="$(SPHINX_CONF)" \
+		--builddir="$(BUILDDIR)" \
+		--theme=$(DOCS_THEME) --css=$(DOCS_CSS) --paper=$(PAPER)
 # If Rust support is available and .config exists, add rustdoc generated contents.
 # If there are any, the errors from this make rustdoc will be displayed but
 # won't stop the execution of htmldocs
@@ -118,49 +87,6 @@ ifeq ($(CONFIG_RUST),y)
 endif
 endif
 
-texinfodocs:
-	@$(srctree)/tools/docs/sphinx-pre-install --version-check
-	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,texinfo,$(var),texinfo,$(var)))
-
-# Note: the 'info' Make target is generated by sphinx itself when
-# running the texinfodocs target define above.
-infodocs: texinfodocs
-	$(MAKE) -C $(BUILDDIR)/texinfo info
-
-linkcheckdocs:
-	@$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,linkcheck,$(var),,$(var)))
-
-latexdocs:
-	@$(srctree)/tools/docs/sphinx-pre-install --version-check
-	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,latex,$(var),latex,$(var)))
-
-ifeq ($(HAVE_PDFLATEX),0)
-
-pdfdocs:
-	$(warning The '$(PDFLATEX)' command was not found. Make sure you have it installed and in PATH to produce PDF output.)
-	@echo "  SKIP    Sphinx $@ target."
-
-else # HAVE_PDFLATEX
-
-pdfdocs: DENY_VF = XDG_CONFIG_HOME=$(FONTS_CONF_DENY_VF)
-pdfdocs: latexdocs
-	@$(srctree)/tools/docs/sphinx-pre-install --version-check
-	$(foreach var,$(SPHINXDIRS), \
-	   $(MAKE) PDFLATEX="$(PDFLATEX)" LATEXOPTS="$(LATEXOPTS)" $(DENY_VF) -C $(BUILDDIR)/$(var)/latex || sh $(srctree)/tools/docs/check-variable-fonts.py || exit; \
-	   mkdir -p $(BUILDDIR)/$(var)/pdf; \
-	   mv $(subst .tex,.pdf,$(wildcard $(BUILDDIR)/$(var)/latex/*.tex)) $(BUILDDIR)/$(var)/pdf/; \
-	)
-
-endif # HAVE_PDFLATEX
-
-epubdocs:
-	@$(srctree)/tools/docs/sphinx-pre-install --version-check
-	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,epub,$(var),epub,$(var)))
-
-xmldocs:
-	@$(srctree)/tools/docs/sphinx-pre-install --version-check
-	@+$(foreach var,$(SPHINXDIRS),$(call loop_cmd,sphinx,xml,$(var),xml,$(var)))
-
 endif # HAVE_SPHINX
 
 # The following targets are independent of HAVE_SPHINX, and the rules should
@@ -172,6 +98,9 @@ refcheckdocs:
 cleandocs:
 	$(Q)rm -rf $(BUILDDIR)
 
+# Used only on help
+_SPHINXDIRS   = $(sort $(patsubst $(srctree)/Documentation/%/index.rst,%,$(wildcard $(srctree)/Documentation/*/index.rst)))
+
 dochelp:
 	@echo  ' Linux kernel internal documentation in different formats from ReST:'
 	@echo  '  htmldocs        - HTML'
diff --git a/tools/docs/sphinx-build-wrapper b/tools/docs/sphinx-build-wrapper
new file mode 100755
index 000000000000..a65a2297eb40
--- /dev/null
+++ b/tools/docs/sphinx-build-wrapper
@@ -0,0 +1,581 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2025 Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
+#
+# pylint: disable=R0902, R0912, R0913, R0914, R0915, R0917, C0103
+#
+# Converted from docs Makefile and parallel-wrapper.sh, both under
+# GPLv2, copyrighted since 2008 by the following authors:
+#
+#    Akira Yokosawa <akiyks@gmail.com>
+#    Arnd Bergmann <arnd@arndb.de>
+#    Breno Leitao <leitao@debian.org>
+#    Carlos Bilbao <carlos.bilbao@amd.com>
+#    Dave Young <dyoung@redhat.com>
+#    Donald Hunter <donald.hunter@gmail.com>
+#    Geert Uytterhoeven <geert+renesas@glider.be>
+#    Jani Nikula <jani.nikula@intel.com>
+#    Jan Stancek <jstancek@redhat.com>
+#    Jonathan Corbet <corbet@lwn.net>
+#    Joshua Clayton <stillcompiling@gmail.com>
+#    Kees Cook <keescook@chromium.org>
+#    Linus Torvalds <torvalds@linux-foundation.org>
+#    Magnus Damm <damm+renesas@opensource.se>
+#    Masahiro Yamada <masahiroy@kernel.org>
+#    Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
+#    Maxim Cournoyer <maxim.cournoyer@gmail.com>
+#    Peter Foley <pefoley2@pefoley.com>
+#    Randy Dunlap <rdunlap@infradead.org>
+#    Rob Herring <robh@kernel.org>
+#    Shuah Khan <shuahkh@osg.samsung.com>
+#    Thorsten Blum <thorsten.blum@toblux.com>
+#    Tomas Winkler <tomas.winkler@intel.com>
+
+
+"""
+Sphinx build wrapper that handles Kernel-specific business rules:
+
+- it gets the Kernel build environment vars;
+- it determines what's the best parallelism;
+- it handles SPHINXDIRS
+
+This tool ensures that MIN_PYTHON_VERSION is satisfied. If version is
+below that, it seeks for a new Python version. If found, it re-runs using
+the newer version.
+"""
+
+import argparse
+import os
+import shlex
+import shutil
+import subprocess
+import sys
+
+from lib.python_version import PythonVersion
+from lib.latex_fonts import LatexFontChecker
+
+LIB_DIR = "../../scripts/lib"
+SRC_DIR = os.path.dirname(os.path.realpath(__file__))
+
+sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR))
+
+from jobserver import JobserverExec         # pylint: disable=C0413,C0411,E0401
+
+#
+#  Some constants
+#
+MIN_PYTHON_VERSION = PythonVersion("3.7").version
+PAPER = ["", "a4", "letter"]
+
+TARGETS = {
+    "cleandocs":     { "builder": "clean" },
+    "linkcheckdocs": { "builder": "linkcheck" },
+    "htmldocs":      { "builder": "html" },
+    "epubdocs":      { "builder": "epub",    "out_dir": "epub" },
+    "texinfodocs":   { "builder": "texinfo", "out_dir": "texinfo" },
+    "infodocs":      { "builder": "texinfo", "out_dir": "texinfo" },
+    "latexdocs":     { "builder": "latex",   "out_dir": "latex" },
+    "pdfdocs":       { "builder": "latex",   "out_dir": "latex" },
+    "xmldocs":       { "builder": "xml",     "out_dir": "xml" },
+}
+
+
+#
+# SphinxBuilder class
+#
+
+class SphinxBuilder:
+    """
+    Handles a sphinx-build target, adding needed arguments to build
+    with the Kernel.
+    """
+
+    def is_rust_enabled(self):
+        """Check if rust is enabled at .config"""
+        config_path = os.path.join(self.srctree, ".config")
+        if os.path.isfile(config_path):
+            with open(config_path, "r", encoding="utf-8") as f:
+                return "CONFIG_RUST=y" in f.read()
+        return False
+
+    def get_path(self, path, use_cwd=False, abs_path=False):
+        """
+        Ancillary routine to handle patches the right way, as shell does.
+
+        It first expands "~" and "~user". Then, if patch is not absolute,
+        join self.srctree. Finally, if requested, convert to abspath.
+        """
+
+        path = os.path.expanduser(path)
+        if not path.startswith("/"):
+            if use_cwd:
+                base = os.getcwd()
+            else:
+                base = self.srctree
+
+            path = os.path.join(base, path)
+
+        if abs_path:
+            return os.path.abspath(path)
+
+        return path
+
+    def get_sphinx_extra_opts(self, n_jobs):
+        """
+        Get the number of jobs to be used for docs build passed via command
+        line and desired sphinx verbosity.
+
+        The number of jobs can be on different places:
+
+        1) It can be passed via "-j" argument;
+        2) The SPHINXOPTS="-j8" env var may have "-j";
+        3) if called via GNU make, -j specifies the desired number of jobs.
+           with GNU makefile, this number is available via POSIX jobserver;
+        4) if none of the above is available, it should default to "-jauto",
+           and let sphinx decide the best value.
+        """
+
+        #
+        # SPHINXOPTS env var, if used, contains extra arguments to be used
+        # by sphinx-build time. Among them, it may contain sphinx verbosity
+        # and desired number of parallel jobs.
+        #
+        parser = argparse.ArgumentParser()
+        parser.add_argument('-j', '--jobs', type=int)
+        parser.add_argument('-q', '--quiet', type=int)
+
+        #
+        # Other sphinx-build arguments go as-is, so place them
+        # at self.sphinxopts, using shell parser
+        #
+        sphinxopts = shlex.split(os.environ.get("SPHINXOPTS", ""))
+
+        #
+        # Build a list of sphinx args, honoring verbosity here if specified
+        #
+
+        verbose = self.verbose
+        sphinx_args, self.sphinxopts = parser.parse_known_args(sphinxopts)
+        if sphinx_args.quiet is True:
+            verbose = False
+
+        #
+        # If the user explicitly sets "-j" at command line, use it.
+        # Otherwise, pick it from SPHINXOPTS args
+        #
+        if n_jobs:
+            self.n_jobs = n_jobs
+        elif sphinx_args.jobs:
+            self.n_jobs = sphinx_args.jobs
+        else:
+            self.n_jobs = None
+
+        if not verbose:
+            self.sphinxopts += ["-q"]
+
+    def __init__(self, builddir, verbose=False, n_jobs=None):
+        """Initialize internal variables"""
+        self.verbose = None
+
+        #
+        # Normal variables passed from Kernel's makefile
+        #
+        self.kernelversion = os.environ.get("KERNELVERSION", "unknown")
+        self.kernelrelease = os.environ.get("KERNELRELEASE", "unknown")
+        self.pdflatex = os.environ.get("PDFLATEX", "xelatex")
+        self.latexopts = os.environ.get("LATEXOPTS", "-interaction=batchmode -no-shell-escape")
+
+        if not verbose:
+            verbose = bool(os.environ.get("KBUILD_VERBOSE", "") != "")
+
+        if verbose is not None:
+            self.verbose = verbose
+
+        #
+        # Source tree directory. This needs to be at os.environ, as
+        # Sphinx extensions use it
+        #
+        self.srctree = os.environ.get("srctree")
+        if not self.srctree:
+            self.srctree = "."
+            os.environ["srctree"] = self.srctree
+
+        #
+        # Now that we can expand srctree, get other directories as well
+        #
+        self.sphinxbuild = os.environ.get("SPHINXBUILD", "sphinx-build")
+        self.kerneldoc = self.get_path(os.environ.get("KERNELDOC",
+                                                      "scripts/kernel-doc.py"))
+        self.builddir = self.get_path(builddir, use_cwd=True, abs_path=True)
+
+        self.config_rust = self.is_rust_enabled()
+
+        #
+        # Get directory locations for LaTeX build toolchain
+        #
+        self.pdflatex_cmd = shutil.which(self.pdflatex)
+        self.latexmk_cmd = shutil.which("latexmk")
+
+        self.env = os.environ.copy()
+
+        self.get_sphinx_extra_opts(n_jobs)
+
+    def run_sphinx(self, sphinx_build, build_args, *args, **pwargs):
+        """
+        Executes sphinx-build using current python3 command.
+
+        When calling via GNU make, POSIX jobserver is used to tell how
+        many jobs are still available from a job pool. claim all remaining
+        jobs, as we don't want sphinx-build to run in parallel with other
+        jobs.
+
+        Despite that, the user may actually force a different value than
+        the number of available jobs via command line.
+
+        The "with" logic here is used to ensure that the claimed jobs will
+        be freed once subprocess finishes
+        """
+
+        with JobserverExec() as jobserver:
+            if jobserver.claim:
+                #
+                # when GNU make is used, claim available jobs from jobserver
+                #
+                n_jobs = str(jobserver.claim)
+            else:
+                #
+                # Otherwise, let sphinx decide by default
+                #
+                n_jobs = "auto"
+
+            #
+            # If explicitly requested via command line, override default
+            #
+            if self.n_jobs:
+                n_jobs = str(self.n_jobs)
+
+            cmd = [sys.executable, sphinx_build]
+            cmd += [f"-j{n_jobs}"]
+            cmd += self.sphinxopts
+            cmd += build_args
+
+            if self.verbose:
+                print(" ".join(cmd))
+
+            return subprocess.call(cmd, *args, **pwargs)
+
+    def handle_html(self, css, output_dir):
+        """
+        Extra steps for HTML and epub output.
+
+        For such targets, we need to ensure that CSS will be properly
+        copied to the output _static directory
+        """
+
+        if not css:
+            return
+
+        css = os.path.expanduser(css)
+        if not css.startswith("/"):
+            css = os.path.join(self.srctree, css)
+
+        static_dir = os.path.join(output_dir, "_static")
+        os.makedirs(static_dir, exist_ok=True)
+
+        try:
+            shutil.copy2(css, static_dir)
+        except (OSError, IOError) as e:
+            print(f"Warning: Failed to copy CSS: {e}", file=sys.stderr)
+
+    def handle_pdf(self, output_dirs):
+        """
+        Extra steps for PDF output.
+
+        As PDF is handled via a LaTeX output, after building the .tex file,
+        a new build is needed to create the PDF output from the latex
+        directory.
+        """
+        builds = {}
+        max_len = 0
+
+        for from_dir in output_dirs:
+            pdf_dir = os.path.join(from_dir, "../pdf")
+            os.makedirs(pdf_dir, exist_ok=True)
+
+            if self.latexmk_cmd:
+                latex_cmd = [self.latexmk_cmd, f"-{self.pdflatex}"]
+            else:
+                latex_cmd = [self.pdflatex]
+
+            latex_cmd.extend(shlex.split(self.latexopts))
+
+            tex_suffix = ".tex"
+
+            #
+            # Process each .tex file
+            #
+
+            has_tex = False
+            build_failed = False
+            with os.scandir(from_dir) as it:
+                for entry in it:
+                    if not entry.name.endswith(tex_suffix):
+                        continue
+
+                    name = entry.name[:-len(tex_suffix)]
+                    has_tex = True
+
+                    #
+                    # LaTeX PDF error code is almost useless for us:
+                    # any warning makes it non-zero. For kernel doc builds it
+                    # always return non-zero even when build succeeds.
+                    # So, let's do the best next thing: check if all PDF
+                    # files were built. If they're, print a summary and
+                    # return 0 at the end of this function
+                    #
+                    try:
+                        subprocess.run(latex_cmd + [entry.path],
+                                       cwd=from_dir, check=True)
+                    except subprocess.CalledProcessError:
+                        pass
+
+                    pdf_name = name + ".pdf"
+                    pdf_from = os.path.join(from_dir, pdf_name)
+                    pdf_to = os.path.join(pdf_dir, pdf_name)
+
+                    if os.path.exists(pdf_from):
+                        os.rename(pdf_from, pdf_to)
+                        builds[name] = os.path.relpath(pdf_to, self.builddir)
+                    else:
+                        builds[name] = "FAILED"
+                        build_failed = True
+
+                    name = entry.name.removesuffix(".tex")
+                    max_len = max(max_len, len(name))
+
+            if not has_tex:
+                name = os.path.basename(from_dir)
+                max_len = max(max_len, len(name))
+                builds[name] = "FAILED (no .tex)"
+                build_failed = True
+
+        msg = "Summary"
+        msg += "\n" + "=" * len(msg)
+        print()
+        print(msg)
+
+        for pdf_name, pdf_file in builds.items():
+            print(f"{pdf_name:<{max_len}}: {pdf_file}")
+
+        print()
+
+        if build_failed:
+            msg = LatexFontChecker().check()
+            if msg:
+                print(msg)
+
+            sys.exit("PDF build failed: not all PDF files were created.")
+        else:
+            print("All PDF files were built.")
+
+    def handle_info(self, output_dirs):
+        """
+        Extra steps for Info output.
+
+        For texinfo generation, an additional make is needed from the
+        texinfo directory.
+        """
+
+        for output_dir in output_dirs:
+            try:
+                subprocess.run(["make", "info"], cwd=output_dir, check=True)
+            except subprocess.CalledProcessError as e:
+                sys.exit(f"Error generating info docs: {e}")
+
+    def cleandocs(self, builder):           # pylint: disable=W0613
+        """Remove documentation output directory"""
+        shutil.rmtree(self.builddir, ignore_errors=True)
+
+    def build(self, target, sphinxdirs=None, conf="conf.py",
+              theme=None, css=None, paper=None):
+        """
+        Build documentation using Sphinx. This is the core function of this
+        module. It prepares all arguments required by sphinx-build.
+        """
+
+        builder = TARGETS[target]["builder"]
+        out_dir = TARGETS[target].get("out_dir", "")
+
+        #
+        # Cleandocs doesn't require sphinx-build
+        #
+        if target == "cleandocs":
+            self.cleandocs(builder)
+            return
+
+        if theme:
+            os.environ["DOCS_THEME"] = theme
+
+        #
+        # Other targets require sphinx-build, so check if it exists
+        #
+        sphinxbuild = shutil.which(self.sphinxbuild, path=self.env["PATH"])
+        if not sphinxbuild:
+            sys.exit(f"Error: {self.sphinxbuild} not found in PATH.\n")
+
+        if builder == "latex":
+            if not self.pdflatex_cmd and not self.latexmk_cmd:
+                sys.exit("Error: pdflatex or latexmk required for PDF generation")
+
+        docs_dir = os.path.abspath(os.path.join(self.srctree, "Documentation"))
+
+        #
+        # Fill in base arguments for Sphinx build
+        #
+        kerneldoc = self.kerneldoc
+        if kerneldoc.startswith(self.srctree):
+            kerneldoc = os.path.relpath(kerneldoc, self.srctree)
+
+        args = [ "-b", builder, "-c", docs_dir ]
+
+        if builder == "latex":
+            if not paper:
+                paper = PAPER[1]
+
+            args.extend(["-D", f"latex_elements.papersize={paper}paper"])
+
+        if self.config_rust:
+            args.extend(["-t", "rustdoc"])
+
+        if conf:
+            self.env["SPHINX_CONF"] = self.get_path(conf, abs_path=True)
+
+        if not sphinxdirs:
+            sphinxdirs = os.environ.get("SPHINXDIRS", ".")
+
+        #
+        # sphinxdirs can be a list or a whitespace-separated string
+        #
+        sphinxdirs_list = []
+        for sphinxdir in sphinxdirs:
+            if isinstance(sphinxdir, list):
+                sphinxdirs_list += sphinxdir
+            else:
+                sphinxdirs_list += sphinxdir.split()
+
+        #
+        # Step 1:  Build each directory in separate.
+        #
+        # This is not the best way of handling it, as cross-references between
+        # them will be broken, but this is what we've been doing since
+        # the beginning.
+        #
+        output_dirs = []
+        for sphinxdir in sphinxdirs_list:
+            src_dir = os.path.join(docs_dir, sphinxdir)
+            doctree_dir = os.path.join(self.builddir, ".doctrees")
+            output_dir = os.path.join(self.builddir, sphinxdir, out_dir)
+
+            #
+            # Make directory names canonical
+            #
+            src_dir = os.path.normpath(src_dir)
+            doctree_dir = os.path.normpath(doctree_dir)
+            output_dir = os.path.normpath(output_dir)
+
+            os.makedirs(doctree_dir, exist_ok=True)
+            os.makedirs(output_dir, exist_ok=True)
+
+            output_dirs.append(output_dir)
+
+            build_args = args + [
+                "-d", doctree_dir,
+                "-D", f"kerneldoc_bin={kerneldoc}",
+                "-D", f"version={self.kernelversion}",
+                "-D", f"release={self.kernelrelease}",
+                "-D", f"kerneldoc_srctree={self.srctree}",
+                src_dir,
+                output_dir,
+            ]
+
+            try:
+                self.run_sphinx(sphinxbuild, build_args, env=self.env)
+            except (OSError, ValueError, subprocess.SubprocessError) as e:
+                sys.exit(f"Build failed: {repr(e)}")
+
+            #
+            # Ensure that each html/epub output will have needed static files
+            #
+            if target in ["htmldocs", "epubdocs"]:
+                self.handle_html(css, output_dir)
+
+        #
+        # Step 2: Some targets (PDF and info) require an extra step once
+        #         sphinx-build finishes
+        #
+        if target == "pdfdocs":
+            self.handle_pdf(output_dirs)
+        elif target == "infodocs":
+            self.handle_info(output_dirs)
+
+def jobs_type(value):
+    """
+    Handle valid values for -j. Accepts Sphinx "-jauto", plus a number
+    equal or bigger than one.
+    """
+    if value is None:
+        return None
+
+    if value.lower() == 'auto':
+        return value.lower()
+
+    try:
+        if int(value) >= 1:
+            return value
+
+        raise argparse.ArgumentTypeError(f"Minimum jobs is 1, got {value}")
+    except ValueError:
+        raise argparse.ArgumentTypeError(f"Must be 'auto' or positive integer, got {value}")  # pylint: disable=W0707
+
+def main():
+    """
+    Main function. The only mandatory argument is the target. If not
+    specified, the other arguments will use default values if not
+    specified at os.environ.
+    """
+    parser = argparse.ArgumentParser(description="Kernel documentation builder")
+
+    parser.add_argument("target", choices=list(TARGETS.keys()),
+                        help="Documentation target to build")
+    parser.add_argument("--sphinxdirs", nargs="+",
+                        help="Specific directories to build")
+    parser.add_argument("--conf", default="conf.py",
+                        help="Sphinx configuration file")
+    parser.add_argument("--builddir", default="output",
+                        help="Sphinx configuration file")
+
+    parser.add_argument("--theme", help="Sphinx theme to use")
+
+    parser.add_argument("--css", help="Custom CSS file for HTML/EPUB")
+
+    parser.add_argument("--paper", choices=PAPER, default=PAPER[0],
+                        help="Paper size for LaTeX/PDF output")
+
+    parser.add_argument("-v", "--verbose", action='store_true',
+                        help="place build in verbose mode")
+
+    parser.add_argument('-j', '--jobs', type=jobs_type,
+                        help="Sets number of jobs to use with sphinx-build")
+
+    args = parser.parse_args()
+
+    PythonVersion.check_python(MIN_PYTHON_VERSION)
+
+    builder = SphinxBuilder(builddir=args.builddir,
+                            verbose=args.verbose, n_jobs=args.jobs)
+
+    builder.build(args.target, sphinxdirs=args.sphinxdirs, conf=args.conf,
+                  theme=args.theme, css=args.css, paper=args.paper)
+
+if __name__ == "__main__":
+    main()
-- 
2.51.0
Re: [PATCH v6 10/21] tools/docs: sphinx-build-wrapper: add a wrapper for sphinx-build
Posted by Akira Yokosawa 2 weeks, 1 day ago
[+CC: Jani, -CC: rust people and list]

On Tue, 16 Sep 2025 12:22:46 +0200, Mauro Carvalho Chehab wrote:
> There are too much magic inside docs Makefile to properly run
> sphinx-build. Create an ancillary script that contains all
> kernel-related sphinx-build call logic currently at Makefile.
> 
> Such script is designed to work both as an standalone command
> and as part of a Makefile. As such, it properly handles POSIX
> jobserver used by GNU make.
> 
> On a side note, there was a line number increase due to the
> conversion (ignoring comments) is:
> 
>  Documentation/Makefile          |  131 +++----------
>  tools/docs/sphinx-build-wrapper |  293 +++++++++++++++++++++++++++++++
>  2 files changed, 323 insertions(+), 101 deletions(-)
> 
> Comments and descriptions adds:
>  tools/docs/sphinx-build-wrapper | 261 +++++++++++++++++++++++++++++++-
> 
> So, about half of the script are comments/descriptions.
> 
> This is because some things are more verbosed on Python and because
> it requires reading env vars from Makefile. Besides it, this script
> has some extra features that don't exist at the Makefile:
> 
> - It can be called directly from command line;
> - It properly return PDF build errors.
> 
> When running the script alone, it will only take handle sphinx-build
> targets. On other words, it won't runn make rustdoc after building
> htmlfiles, nor it will run the extra check scripts.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> ---
>  Documentation/Makefile          | 131 ++-----
>  tools/docs/sphinx-build-wrapper | 581 ++++++++++++++++++++++++++++++++
>  2 files changed, 611 insertions(+), 101 deletions(-)
>  create mode 100755 tools/docs/sphinx-build-wrapper
> 
> diff --git a/Documentation/Makefile b/Documentation/Makefile
> index 7570d4cf3b13..4736f02b6c9e 100644
> --- a/Documentation/Makefile
> +++ b/Documentation/Makefile
> @@ -23,21 +23,22 @@ SPHINXOPTS    =
>  SPHINXDIRS    = .
>  DOCS_THEME    =
>  DOCS_CSS      =
> -_SPHINXDIRS   = $(sort $(patsubst $(srctree)/Documentation/%/index.rst,%,$(wildcard $(srctree)/Documentation/*/index.rst)))

Wait!  In the cover-letter, you said:

    It should be noticed that it is out of the scope of this series
    to change the implementation. Surely the process can be improved,
    but first let's consolidate and document everything on a single
    place.

Removing current restriction on SPHINXDIRS does look inconsistent with
your own words to me.

So, I guess I have to NAK 06/21 as well.

Regards,
Akira
Re: [PATCH v6 10/21] tools/docs: sphinx-build-wrapper: add a wrapper for sphinx-build
Posted by Mauro Carvalho Chehab 2 weeks ago
On Wed, Sep 17, 2025 at 05:35:31PM +0900, Akira Yokosawa wrote:
> [+CC: Jani, -CC: rust people and list]
> 
> On Tue, 16 Sep 2025 12:22:46 +0200, Mauro Carvalho Chehab wrote:
> > There are too much magic inside docs Makefile to properly run
> > sphinx-build. Create an ancillary script that contains all
> > kernel-related sphinx-build call logic currently at Makefile.
> > 
> > Such script is designed to work both as an standalone command
> > and as part of a Makefile. As such, it properly handles POSIX
> > jobserver used by GNU make.
> > 
> > On a side note, there was a line number increase due to the
> > conversion (ignoring comments) is:
> > 
> >  Documentation/Makefile          |  131 +++----------
> >  tools/docs/sphinx-build-wrapper |  293 +++++++++++++++++++++++++++++++
> >  2 files changed, 323 insertions(+), 101 deletions(-)
> > 
> > Comments and descriptions adds:
> >  tools/docs/sphinx-build-wrapper | 261 +++++++++++++++++++++++++++++++-
> > 
> > So, about half of the script are comments/descriptions.
> > 
> > This is because some things are more verbosed on Python and because
> > it requires reading env vars from Makefile. Besides it, this script
> > has some extra features that don't exist at the Makefile:
> > 
> > - It can be called directly from command line;
> > - It properly return PDF build errors.
> > 
> > When running the script alone, it will only take handle sphinx-build
> > targets. On other words, it won't runn make rustdoc after building
> > htmlfiles, nor it will run the extra check scripts.
> > 
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> > ---
> >  Documentation/Makefile          | 131 ++-----
> >  tools/docs/sphinx-build-wrapper | 581 ++++++++++++++++++++++++++++++++
> >  2 files changed, 611 insertions(+), 101 deletions(-)
> >  create mode 100755 tools/docs/sphinx-build-wrapper
> > 
> > diff --git a/Documentation/Makefile b/Documentation/Makefile
> > index 7570d4cf3b13..4736f02b6c9e 100644
> > --- a/Documentation/Makefile
> > +++ b/Documentation/Makefile
> > @@ -23,21 +23,22 @@ SPHINXOPTS    =
> >  SPHINXDIRS    = .
> >  DOCS_THEME    =
> >  DOCS_CSS      =
> > -_SPHINXDIRS   = $(sort $(patsubst $(srctree)/Documentation/%/index.rst,%,$(wildcard $(srctree)/Documentation/*/index.rst)))
> 
> Wait!  In the cover-letter, you said:
> 
>     It should be noticed that it is out of the scope of this series
>     to change the implementation. Surely the process can be improved,
>     but first let's consolidate and document everything on a single
>     place.
> 
> Removing current restriction on SPHINXDIRS does look inconsistent with
> your own words to me.

You misread the patch. Look better some hunks below:

    +# Used only on help
    +_SPHINXDIRS   = $(sort $(patsubst $(srctree)/Documentation/%/index.rst,%,$(wildcard $(srctree)/Documentation/*/index.rst)))
    +

Patch doesn't remove _SPHINXDIRS. It just moves it to be closer to the
help and document that this is used only there.

> 
> So, I guess I have to NAK 06/21 as well.
> 
> Regards,
> Akira
> 

-- 
Thanks,
Mauro
Re: [PATCH v6 10/21] tools/docs: sphinx-build-wrapper: add a wrapper for sphinx-build
Posted by Jonathan Corbet 2 weeks ago
Akira Yokosawa <akiyks@gmail.com> writes:

> Wait!  In the cover-letter, you said:
>
>     It should be noticed that it is out of the scope of this series
>     to change the implementation. Surely the process can be improved,
>     but first let's consolidate and document everything on a single
>     place.
>
> Removing current restriction on SPHINXDIRS does look inconsistent with
> your own words to me.
>
> So, I guess I have to NAK 06/21 as well.

Is there an actual problem with this change that we need to know about?
I am not quite understanding the objection here.

Thanks,

jon
Re: [PATCH v6 10/21] tools/docs: sphinx-build-wrapper: add a wrapper for sphinx-build
Posted by Akira Yokosawa 2 weeks ago
Hi Jon,

Jonathan Corbet wrote:
> Akira Yokosawa <akiyks@gmail.com> writes:
> 
>> Wait!  In the cover-letter, you said:
>>
>>     It should be noticed that it is out of the scope of this series
>>     to change the implementation. Surely the process can be improved,
>>     but first let's consolidate and document everything on a single
>>     place.
>>
>> Removing current restriction on SPHINXDIRS does look inconsistent with
>> your own words to me.
>>
>> So, I guess I have to NAK 06/21 as well.
> 
> Is there an actual problem with this change that we need to know about?
> I am not quite understanding the objection here.

As Mauro has pointed out, and as I could not apply v6 series, I failed
to look at the whole patch.

My knee jerk reaction came from the fact that, for example,

    make SPHINXDIRS=translations/zh_CN pdfdocs

won't build.  This is because I didn't know such a sub-directory is
allowed (despite what "make dochelp" says) in SPHINXDIRS.

At the time I made "improvements in CJK font configs", I embedded
hacky ".. raw:: latex     \kerneldocCJKoff" and others in:

     Documentations/index.rst
                   /*/index.rst

, assuming all of those latex macros would appear in translations.tex
in the right order.

I admit it was not ideal, but I could not, and still can not, come up
with a more robust approach.

Hopefully, this explains enough for you.

Regards,
Akira
Re: [PATCH v6 10/21] tools/docs: sphinx-build-wrapper: add a wrapper for sphinx-build
Posted by Mauro Carvalho Chehab 2 weeks ago
Em Thu, 18 Sep 2025 08:43:19 +0900
Akira Yokosawa <akiyks@gmail.com> escreveu:

> Hi Jon,
> 
> Jonathan Corbet wrote:
> > Akira Yokosawa <akiyks@gmail.com> writes:
> >   
> >> Wait!  In the cover-letter, you said:
> >>
> >>     It should be noticed that it is out of the scope of this series
> >>     to change the implementation. Surely the process can be improved,
> >>     but first let's consolidate and document everything on a single
> >>     place.
> >>
> >> Removing current restriction on SPHINXDIRS does look inconsistent with
> >> your own words to me.
> >>
> >> So, I guess I have to NAK 06/21 as well.  
> > 
> > Is there an actual problem with this change that we need to know about?
> > I am not quite understanding the objection here.  
> 
> As Mauro has pointed out, and as I could not apply v6 series, I failed
> to look at the whole patch.
> 
> My knee jerk reaction came from the fact that, for example,
> 
>     make SPHINXDIRS=translations/zh_CN pdfdocs
> 
> won't build.  This is because I didn't know such a sub-directory is
> allowed (despite what "make dochelp" says) in SPHINXDIRS.

The build system does support it, provided that the directory has
an index.rst file (not all subdirs have)...

> 
> At the time I made "improvements in CJK font configs", I embedded
> hacky ".. raw:: latex     \kerneldocCJKoff" and others in:
> 
>      Documentations/index.rst
>                    /*/index.rst

... and that ".. raw:: " entries don't depend on previous .rst files.

> , assuming all of those latex macros would appear in translations.tex
> in the right order.
> 
> I admit it was not ideal, but I could not, and still can not, come up
> with a more robust approach.

For LaTeX build, ".. raw:: " entries can be unavoidable, but you could
place it either:

- at conf.py if they're global;
- on each rst file (that's what we do on media);
- in the case of translations, for the languages that require CJK.

Grepping it:

	$ git grep kerneldocCJK Documentation/translations/
	Documentation/translations/index.rst:   \kerneldocCJKoff
	Documentation/translations/it_IT/index.rst:     \kerneldocCJKoff
	Documentation/translations/ja_JP/index.rst:     \kerneldocCJKon
	Documentation/translations/ko_KR/index.rst:     \kerneldocCJKon
	Documentation/translations/ko_KR/process/howto.rst:     \kerneldocCJKoff
	Documentation/translations/ko_KR/process/howto.rst:     \kerneldocCJKon
	Documentation/translations/sp_SP/index.rst:     \kerneldocCJKoff
	Documentation/translations/zh_CN/index.rst:     \kerneldocCJKon
	Documentation/translations/zh_TW/index.rst:     \kerneldocCJKon

Indeed it assumes that translations/index.rst will be the last one,
as it is needed to disable \kerneldocCJKoff.

What I would do is move \kerneldocCJK to each book, e.g.:

   zh_CN/index:	will have a \kerneldocCJK{on/off} pair;
   zh_TW/index:	will have a \kerneldocCJK{on/off} pair;
   it_IT/index: won't use it, as it doesn't need CJK fonts;
   ko_KR/index:	will have a \kerneldocCJK{on/off} pair;
   ja_JP/index:	will have a \kerneldocCJK{on/off} pair;
   sp_SP/index:	will have a \kerneldocCJK{on/off} pair;
   process/index: won't use it, as everything there is in English;

This would likely allow creating each translation on separate books
like:

	make SPHINXDIRS="translations/zh_CN translations/ko_KR ..." pdfdocs

Heh, the audience for each language is completely different, so
merging them altogether is actually weird. This doesn't matter 
much for html output, but for all other outputs, ideally each
translation should be a separate book.

With the current Makefile-hacky-based-approach, supporting separate
build books would be very complex, but with a wrapper containing the
entire building logic, it doesn't sound hard to add support in the
future to build translations as separate entities.=

Heh, when we added Sphinx support, we have a single Documentation
directory, but now we have multiple ones:

	$ find . -name Documentation
	./tools/bpf/bpftool/Documentation
	./tools/perf/Documentation
	./tools/memory-model/Documentation
	./tools/lib/perf/Documentation
	./tools/objtool/Documentation
	./tools/build/Documentation
	./Documentation
	./drivers/staging/most/Documentation
	./drivers/staging/greybus/Documentation
	./drivers/staging/iio/Documentation

Considering that, and considering the some of the above books can
be in ReST format, it doesn't sound too complex to add a --docdir
parameter at sphinx-build-wrapper and do things like:

	./tools/docs/sphinx-build-wrapper --docdir Documentation/translations/zh_CN htmldocs
	./tools/docs/sphinx-build-wrapper --docdir Documentation/translations/zh_TW epubdocs
	./tools/docs/sphinx-build-wrapper --docdir ./tools/bpf/bpftool/Documentation mandocs

On such scenario, we likely need intersphinx, as translation books contain lots of
references pointing to the English one.


Thanks,
Mauro
Re: [PATCH v6 10/21] tools/docs: sphinx-build-wrapper: add a wrapper for sphinx-build
Posted by Akira Yokosawa 2 weeks, 1 day ago
On Wed, 17 Sep 2025 17:35:31 +0900, Akira Yokosawa wrote:
> So, I guess I have to NAK 06/21 as well.
  I meant                   10/21.

Sorry for the noise.

> 
> Regards,
> Akira
>