Re: [dpdk-dev] [PATCH v2 4/4] build: generate API documentation with Meson

[Bruce Richardson <bruce.richardson@intel.com>]

On Fri, Sep 07, 2018 at 05:55:24PM +0100, Luca Boccassi wrote:
> Signed-off-by: Luca Boccassi <bluca@debian.org>
> ---
> v2: made doxygen dependency optional, skip doxygen build when not found
> 
>  doc/api/generate_doxygen.sh | 10 +++++++
>  doc/api/meson.build         | 54 +++++++++++++++++++++++++++++++++++++
>  doc/build-sdk-meson.txt     |  2 ++
>  doc/meson.build             |  4 +++
>  meson.build                 |  3 +++
>  meson_options.txt           |  2 ++
>  6 files changed, 75 insertions(+)
>  create mode 100755 doc/api/generate_doxygen.sh
>  create mode 100644 doc/api/meson.build
>  create mode 100644 doc/meson.build
> 
> diff --git a/doc/api/generate_doxygen.sh b/doc/api/generate_doxygen.sh
> new file mode 100755
> index 0000000000..ab57660958
> --- /dev/null
> +++ b/doc/api/generate_doxygen.sh
> @@ -0,0 +1,10 @@
> +#! /bin/sh -e
> +# SPDX-License-Identifier: BSD-3-Clause
> +# Copyright 2018 Luca Boccassi <bluca@debian.org>
> +
> +DOXYCONF=$1
> +OUTDIR=$2
> +SCRIPTCSS=$3
> +
> +doxygen "${DOXYCONF}"
> +"${SCRIPTCSS}" "${OUTDIR}"/doxygen.css
> diff --git a/doc/api/meson.build b/doc/api/meson.build
> new file mode 100644
> index 0000000000..5dfa0fe044
> --- /dev/null
> +++ b/doc/api/meson.build
> @@ -0,0 +1,54 @@
> +# SPDX-License-Identifier: BSD-3-Clause
> +# Copyright(c) 2018 Luca Boccassi <bluca@debian.org>
> +
> +doxygen = find_program('doxygen', required: false)

Thinking about it, I think that "required" should be set to
"get_option(enable_docs)", since if someone explicitly enables the docs
they should be built and cause error if they can't be.

> +
> +if doxygen.found()
> +	# due to the CSS customisation script, which needs to run on a file that
> +	# is in a subdirectory that is created at build time and thus it cannot
> +	# be an individual custom_target, we need to wrap the doxygen call in a
> +	# script to run the CSS modification afterwards
> +	generate_doxygen = find_program('generate_doxygen.sh')
> +	generate_examples = find_program('generate_examples.sh')
> +	generate_css = find_program('doxy-html-custom.sh')
> +
> +	inputdir = join_paths(meson.source_root(), 'examples')
> +	htmldir = join_paths('doc', 'html')
> +
> +	# due to the following bug: https://github.com/mesonbuild/meson/issues/4107
> +	# if install is set to true it will override build_by_default and it will
> +	# cause the target to always be built. If install were to be always set to
> +	# false it would be impossible to install the docs.
> +	# So use a configure option for now.
> +	example = custom_target('examples.dox',
> +		input: inputdir,
> +		output: 'examples.dox',
> +		command: [generate_examples, '@INPUT@', '@OUTPUT@'],
> +		install: get_option('enable_docs'),
> +		install_dir: htmldir,
> +		build_by_default: false)
> +
> +	cdata = configuration_data()
> +	cdata.set('VERSION', meson.project_version())
> +	cdata.set('API_EXAMPLES', join_paths(meson.build_root(), 'doc', 'api', 'examples.dox'))
> +	cdata.set('OUTPUT', join_paths(meson.build_root(), 'doc', 'api'))
> +	cdata.set('HTML_OUTPUT', 'api')
> +	cdata.set('TOPDIR', meson.source_root())
> +	cdata.set('STRIP_FROM_PATH', meson.source_root())
> +
> +	doxy_conf = configure_file(input: 'doxy-api.conf.in',
> +		output: 'doxy-api.conf',
> +		configuration: cdata,
> +		install: false)
> +
> +	doxy_build = custom_target('doxygen',
> +		depends: example,
> +		input: doxy_conf,
> +		output: 'api',
> +		command: [generate_doxygen, '@INPUT@', '@OUTPUT@', generate_css],
> +		install: get_option('enable_docs'),
> +		install_dir: htmldir,
> +		build_by_default: false)
> +
> +	run_target('doc', command: 'true', depends: doxy_build)
> +endif

Suggestion: add a run_target in an else leg to just print out "no
doxygen found" or similar message when ninja doc is called.