Merge branch 'sphinx-for-docs-next' into doc/4.8

Jani Nikula says:

Jon, this is v2 of [1] and [2], with a considerable amount of polish and
fixes added. We started dogfooding this within drm-intel, and Daniel has
reviewed the lot and contributed a number of fixes, most notably
accurate file and line number references from Sphinx build
errors/warnings to the kernel-doc comments in source code.

We believe this is now in good shape for merging for v4.8. It's all in
my sphinx-for-docs-next branch that you've already looked at; pull
details below.

When this lands in docs-next and we can backmerge to drm, we'll plunge
ahead and convert gpu.tmpl to rst, and have that ready for v4.8. We
think it's best to contribute that via the drm tree, as it'll involve
splitting up the documentation and likely numerous updates to kernel-doc
comments.

I plan to update Documentation/kernel-doc-nano-HOWTO.txt for Sphinx and
rst, obviously converting it to rst while at it.

Documentation/.gitignore

+output

Documentation/DocBook/Makefile

@@ -33,10 +33,6 @@ PDF_METHOD	= $(prefer-db2x)
 PS_METHOD	= $(prefer-db2x)
 
 
-###
-# The targets that may be used.
-PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs
-
 targets += $(DOCBOOKS)
 BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))
 xmldocs: $(BOOKS)
@@ -63,6 +59,9 @@ installmandocs: mandocs
 		sort -k 2 -k 1 | uniq -f 1 | sed -e 's: :/:' | \
 		xargs install -m 644 -t /usr/local/man/man9/
 
+# no-op for the DocBook toolchain
+epubdocs:
+
 ###
 #External programs used
 KERNELDOCXMLREF = $(srctree)/scripts/kernel-doc-xml-ref

Documentation/Makefile.sphinx

+# -*- makefile -*-
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXBUILD   = sphinx-build
+SPHINXOPTS    =
+PAPER         =
+BUILDDIR      = $(obj)/output
+
+# User-friendly check for sphinx-build
+HAVE_SPHINX := $(shell if which $(SPHINXBUILD) >/dev/null 2>&1; then echo 1; else echo 0; fi)
+
+ifeq ($(HAVE_SPHINX),0)
+
+.DEFAULT:
+	$(warning The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed and in PATH, or set the SPHINXBUILD make variable to point to the full path of the '$(SPHINXBUILD)' executable.)
+	@echo "  SKIP    Sphinx $@ target."
+
+else # HAVE_SPHINX
+
+# User-friendly check for rst2pdf
+HAVE_RST2PDF := $(shell if python -c "import rst2pdf" >/dev/null 2>&1; then echo 1; else echo 0; fi)
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+KERNELDOC       = $(srctree)/scripts/kernel-doc
+KERNELDOC_CONF  = -D kerneldoc_srctree=$(srctree) -D kerneldoc_bin=$(KERNELDOC)
+ALLSPHINXOPTS   = -D version=$(KERNELVERSION) -D release=$(KERNELRELEASE) -d $(BUILDDIR)/.doctrees $(KERNELDOC_CONF) $(PAPEROPT_$(PAPER)) -c $(srctree)/$(src) $(SPHINXOPTS) $(srctree)/$(src)
+# the i18n builder cannot share the environment and doctrees with the others
+I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+
+quiet_cmd_sphinx = SPHINX  $@
+      cmd_sphinx = $(SPHINXBUILD) -b $2 $(ALLSPHINXOPTS) $(BUILDDIR)/$2
+
+htmldocs:
+	$(call cmd,sphinx,html)
+
+pdfdocs:
+ifeq ($(HAVE_RST2PDF),0)
+	$(warning The Python 'rst2pdf' module was not found. Make sure you have the module installed to produce PDF output.)
+	@echo "  SKIP    Sphinx $@ target."
+else # HAVE_RST2PDF
+	$(call cmd,sphinx,pdf)
+endif # HAVE_RST2PDF
+
+epubdocs:
+	$(call cmd,sphinx,epub)
+
+xmldocs:
+	$(call cmd,sphinx,xml)
+
+# no-ops for the Sphinx toolchain
+sgmldocs:
+psdocs:
+mandocs:
+installmandocs:
+
+cleandocs:
+	$(Q)rm -rf $(BUILDDIR)
+
+endif # HAVE_SPHINX

Documentation/index.rst

+.. The Linux Kernel documentation master file, created by
+   sphinx-quickstart on Fri Feb 12 13:51:46 2016.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Welcome to The Linux Kernel's documentation!
+============================================
+
+Nothing for you to see here *yet*. Please move along.
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`
+

Documentation/sphinx/convert_template.sed

+#
+# Pandoc doesn't grok <function> or <structname>, so convert them
+# ahead of time.
+#
+# Use the following escapes to pass through pandoc:
+#	$bq = "`"
+#	$lt = "<"
+#	$gt = ">"
+#
+s%<function>\([^<(]\+\)()</function>%:c:func:$bq\1()$bq%g
+s%<function>\([^<(]\+\)</function>%:c:func:$bq\1()$bq%g
+s%<structname>struct *\([^<]\+\)</structname>%:c:type:$bqstruct \1 $lt\1$gt$bq%g
+s%struct <structname>\([^<]\+\)</structname>%:c:type:$bqstruct \1 $lt\1$gt$bq%g
+s%<structname>\([^<]\+\)</structname>%:c:type:$bqstruct \1 $lt\1$gt$bq%g
+#
+# Wrap docproc directives in para and code blocks.
+#
+s%^\(!.*\)$%<para><code>DOCPROC: \1</code></para>%

Documentation/sphinx/kernel-doc.py

+# coding=utf-8
+#
+# Copyright © 2016 Intel Corporation
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice (including the next
+# paragraph) shall be included in all copies or substantial portions of the
+# Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+#
+# Authors:
+#    Jani Nikula <jani.nikula@intel.com>
+#
+# Please make sure this works on both python2 and python3.
+#
+
+import os
+import subprocess
+import sys
+import re
+
+from docutils import nodes, statemachine
+from docutils.statemachine import ViewList
+from docutils.parsers.rst import directives
+from sphinx.util.compat import Directive
+
+class KernelDocDirective(Directive):
+    """Extract kernel-doc comments from the specified file"""
+    required_argument = 1
+    optional_arguments = 4
+    option_spec = {
+        'doc': directives.unchanged_required,
+        'functions': directives.unchanged_required,
+        'export': directives.flag,
+        'internal': directives.flag,
+    }
+    has_content = False
+
+    def run(self):
+        env = self.state.document.settings.env
+        cmd = [env.config.kerneldoc_bin, '-rst', '-enable-lineno']
+
+        filename = env.config.kerneldoc_srctree + '/' + self.arguments[0]
+
+        # Tell sphinx of the dependency
+        env.note_dependency(os.path.abspath(filename))
+
+        tab_width = self.options.get('tab-width', self.state.document.settings.tab_width)
+        source = filename
+
+        # FIXME: make this nicer and more robust against errors
+        if 'export' in self.options:
+            cmd += ['-export']
+        elif 'internal' in self.options:
+            cmd += ['-internal']
+        elif 'doc' in self.options:
+            cmd += ['-function', str(self.options.get('doc'))]
+        elif 'functions' in self.options:
+            for f in str(self.options.get('functions')).split(' '):
+                cmd += ['-function', f]
+
+        cmd += [filename]
+
+        try:
+            env.app.verbose('calling kernel-doc \'%s\'' % (" ".join(cmd)))
+
+            p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
+            out, err = p.communicate()
+
+            # python2 needs conversion to unicode.
+            # python3 with universal_newlines=True returns strings.
+            if sys.version_info.major < 3:
+                out, err = unicode(out, 'utf-8'), unicode(err, 'utf-8')
+
+            if p.returncode != 0:
+                sys.stderr.write(err)
+
+                env.app.warn('kernel-doc \'%s\' failed with return code %d' % (" ".join(cmd), p.returncode))
+                return [nodes.error(None, nodes.paragraph(text = "kernel-doc missing"))]
+            elif env.config.kerneldoc_verbosity > 0:
+                sys.stderr.write(err)
+
+            lines = statemachine.string2lines(out, tab_width, convert_whitespace=True)
+            result = ViewList()
+
+            lineoffset = 0;
+            line_regex = re.compile("^#define LINENO ([0-9]+)$")
+            for line in lines:
+                match = line_regex.search(line)
+                if match:
+                    # sphinx counts lines from 0
+                    lineoffset = int(match.group(1)) - 1
+                    # we must eat our comments since the upset the markup
+                else:
+                    result.append(line, source, lineoffset)
+                    lineoffset += 1
+
+            node = nodes.section()
+            node.document = self.state.document
+            self.state.nested_parse(result, self.content_offset, node)
+
+            return node.children
+
+        except Exception as e:
+            env.app.warn('kernel-doc \'%s\' processing failed with: %s' %
+                         (" ".join(cmd), str(e)))
+            return [nodes.error(None, nodes.paragraph(text = "kernel-doc missing"))]
+
+def setup(app):
+    app.add_config_value('kerneldoc_bin', None, 'env')
+    app.add_config_value('kerneldoc_srctree', None, 'env')
+    app.add_config_value('kerneldoc_verbosity', 1, 'env')
+
+    app.add_directive('kernel-doc', KernelDocDirective)

Documentation/sphinx/post_convert.sed

+#
+# Unescape.
+#
+s/$bq/`/g
+s/$lt/</g
+s/$gt/>/g
+#
+# pandoc thinks that both "_" needs to be escaped.  Remove the extra
+# backslashes.
+#
+s/\\_/_/g
+#
+# Unwrap docproc directives.
+#
+s/^``DOCPROC: !E\(.*\)``$/.. kernel-doc:: \1\n   :export:/
+s/^``DOCPROC: !I\(.*\)``$/.. kernel-doc:: \1\n   :internal:/
+s/^``DOCPROC: !F\([^ ]*\) \(.*\)``$/.. kernel-doc:: \1\n   :functions: \2/
+s/^``DOCPROC: !P\([^ ]*\) \(.*\)``$/.. kernel-doc:: \1\n   :doc: \2/
+s/^``DOCPROC: \(!.*\)``$/.. WARNING: DOCPROC directive not supported: \1/
+#
+# Trim trailing whitespace.
+#
+s/[[:space:]]*$//

Documentation/sphinx/tmplcvt

+#!/bin/bash
+#
+# Convert a template file into something like RST
+#
+# fix <function>
+# feed to pandoc
+# fix \_
+# title line?
+#
+
+in=$1
+rst=$2
+tmp=$rst.tmp
+
+cp $in $tmp
+sed --in-place -f convert_template.sed $tmp
+pandoc -s -S -f docbook -t rst -o $rst $tmp
+sed --in-place -f post_convert.sed $rst
+rm $tmp

Makefile

@@ -1412,8 +1412,11 @@ $(help-board-dirs): help-%:
 
 # Documentation targets
 # ---------------------------------------------------------------------------
-%docs: scripts_basic FORCE
+DOC_TARGETS := xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs epubdocs cleandocs
+PHONY += $(DOC_TARGETS)
+$(DOC_TARGETS): scripts_basic FORCE
 	$(Q)$(MAKE) $(build)=scripts build_docproc build_check-lc_ctype
+	$(Q)$(MAKE) $(build)=Documentation -f $(srctree)/Documentation/Makefile.sphinx $@
 	$(Q)$(MAKE) $(build)=Documentation/DocBook $@
 
 else # KBUILD_EXTMOD