Re: [RFC PATCH 0/3] Automatically convert configure options to meson build options

From: "罗勇刚(Yonggang Luo)" <luoyonggang@gmail.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>,
	"Daniel P. Berrangé" <berrange@redhat.com>,
	qemu-level <qemu-devel@nongnu.org>,
	"Peter Maydell" <peter.maydell@linaro.org>
Subject: Re: [RFC PATCH 0/3] Automatically convert configure options to meson build options
Date: Sun, 13 Sep 2020 18:15:52 +0800	[thread overview]
Message-ID: <CAE2XoE8sgGfeoxn7+g4vEnYF52Axx3DOA=37hCO05sCkf+cEdw@mail.gmail.com> (raw)
In-Reply-To: <20200913100534.22084-1-pbonzini@redhat.com>

[-- Attachment #1: Type: text/plain, Size: 3060 bytes --]

On Sun, Sep 13, 2020 at 6:07 PM Paolo Bonzini <pbonzini@redhat.com> wrote:

> Right now meson_options.txt lists less than a dozen options, but about
> 40 more could come as configure tests are converted and moved to
> meson.build.  Each option needs code in configure to parse it and pass
> the option down to Meson as a -D command-line argument; in addition the
> default must be duplicated between configure and meson_options.txt.
>
> This series tries to remove the code duplication by passing unknown
> --enable and --disable options to a Python program, and using
> Meson's introspection support to match those to meson_options.txt
>
> The disadvantages are:
>
> - because we parse command-line options before meson is available,
> the introspection output is stored in the source tree.  The output
> is slightly modified using the "jq" tool in order to ensure that it's
> stable and that modifications to meson_buildoptions.txt do not cause
> horrible conflicts.  This is the main reason for the unattractive
> diffstat (the number of JSON lines added is higher than the number
> of configure lines removed, though of course the latter are code
> that must be maintained manually and the former is not).
>
> - we now need Python to generate the full help, so if Python is
> missing we can only print a partial message and direct the user
> to specify the interpreter with --python.  It would be possible to fix
> this by rewriting the script in Perl (at least on Fedora, JSON::PP is
> always installed if Perl is, because it's a dependency for CPAN; I'd
> have to check Ubuntu and the BSDs), or if we want to write it as a
> Bourne shell script, to further massage the introspection output into
> for example TAB-separated values.
>
I am confusing about this? we were converting configure to meson, and
python is a
force dependencies, why we need rewrite the script in Perl? If we wanna
build qemu, the first thing
we need to install is python+meson, so there is no need convert to Perl or
bash script.
And perl/bash will incur msys2/mingw user, the ideal way is we only depends
on python+meson to building qemu

>
> Opinions are welcome on whether this is worthwhile and how to solve
> the above doubts.
>
> Paolo
>
> Paolo Bonzini (3):
>   configure: quote command line arguments in config.status
>   configure: early test for Python
>   configure: automatically parse command line for meson -D options
>
>  Makefile                                |   6 ++
>  configure                               | 107 ++++++++-----------
>  docs/devel/build-system.rst             |  35 +------
>  meson-buildoptions.json                 | 130 ++++++++++++++++++++++++
>  scripts/configure-parse-buildoptions.py |  94 +++++++++++++++++
>  5 files changed, 280 insertions(+), 92 deletions(-)
>  create mode 100644 meson-buildoptions.json
>  create mode 100644 scripts/configure-parse-buildoptions.py
>
> --
> 2.26.2
>
>
>

-- 
         此致
礼
罗勇刚
Yours
    sincerely,
Yonggang Luo

[-- Attachment #2: Type: text/html, Size: 3830 bytes --]