Documentation/sphinx: set version and release properly

PAPEROPT_letter = -D latex_paper_size=letter

KERNELDOC       = $(srctree)/scripts/kernel-doc

KERNELDOC_CONF  = -D kerneldoc_srctree=$(srctree) -D kerneldoc_bin=$(KERNELDOC)

ALLSPHINXOPTS   = -d $(BUILDDIR)/.doctrees $(KERNELDOC_CONF) $(PAPEROPT_$(PAPER)) -c $(srctree)/$(src) $(SPHINXOPTS) $(srctree)/$(src)

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) .

# |version| and |release|, also used in various other places throughout the

# built documents.

#

# The short X.Y version.

version = '4.5'

# The full version, including alpha/beta/rc tags.

release = '4.5'

# In a normal build, version and release are are set to KERNELVERSION and

# KERNELRELEASE, respectively, from the Makefile via Sphinx command line

# arguments.

#

# The following code tries to extract the information by reading the Makefile,

# when Sphinx is run directly (e.g. by Read the Docs).

try:

    makefile_version = None

    makefile_patchlevel = None

    for line in open('../Makefile'):

        key, val = [x.strip() for x in line.split('=', 2)]

        if key == 'VERSION':

            makefile_version = val

        elif key == 'PATCHLEVEL':

            makefile_patchlevel = val

        if makefile_version and makefile_patchlevel:

            break

except:

    pass

finally:

    if makefile_version and makefile_patchlevel:

        version = release = makefile_version + '.' + makefile_patchlevel

    else:

        sys.stderr.write('Warning: Could not extract kernel version\n')

        version = release = "unknown version"

# The language for content autogenerated by Sphinx. Refer to documentation

# for a list of supported languages.