Re: [PATCH v2] scripts: Convert qemu-version.sh to qemu-version.py

[Peter Maydell]

On Mon, 5 Oct 2020 at 18:24, Yonggang Luo <luoyonggang@gmail.com> wrote:
>
> The sh script are harder to maintain for compatible different
> xsh environment
>
> Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
> ---
>  meson.build             |  2 +-
>  scripts/qemu-version.py | 30 ++++++++++++++++++++++++++++++
>  scripts/qemu-version.sh | 25 -------------------------
>  3 files changed, 31 insertions(+), 26 deletions(-)
>  create mode 100644 scripts/qemu-version.py
>  delete mode 100755 scripts/qemu-version.sh
>
> diff --git a/meson.build b/meson.build
> index 95a532bd29..20f653b6eb 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1072,7 +1072,7 @@ tracetool = [
>     '--backend=' + config_host['TRACE_BACKENDS']
>  ]
>
> -qemu_version_cmd = [find_program('scripts/qemu-version.sh'),
> +qemu_version_cmd = [find_program('scripts/qemu-version.py'),
>                      meson.current_source_dir(),
>                      config_host['PKGVERSION'], meson.project_version()]
>  qemu_version = custom_target('qemu-version.h',
> diff --git a/scripts/qemu-version.py b/scripts/qemu-version.py
> new file mode 100644
> index 0000000000..384c54027d
> --- /dev/null
> +++ b/scripts/qemu-version.py
> @@ -0,0 +1,30 @@
> +#!/usr/bin/env python3
> +
> +# Script for retrieve qemu git version information
> +# and output to stdout as QEMU_PKGVERSION and QEMU_FULL_VERSION header
> +# Author: Yonggang Luo <luoyonggang@gmail.com>

Can we have a license statement in all new files, please?

> +
> +import sys
> +import subprocess
> +
> +def main(args):
> +    if len(args) <= 3:
> +        sys.exit(0)
> +
> +    dir = args[1]
> +    pkgversion = args[2]
> +    version = args[3]
> +    pc = subprocess.run(['git', 'describe', '--match', "'v*'", '--dirty', 
> '--always'],
> +        stdout=subprocess.PIPE, stderr=subprocess.DEVNULL, cwd=dir)
> +    if pc.returncode == 0:
> +        pkgversion = pc.stdout.decode('utf8').strip()
> +    fullversion = version
> +    if len(pkgversion) > 0:
> +        fullversion = "{} ({})".format(version, pkgversion)
> +
> +    version_header = '''#define QEMU_PKGVERSION "{}"
> +#define QEMU_FULL_VERSION "{}"'''.format(pkgversion, fullversion)
> +    sys.stdout.buffer.write(version_header.encode('utf8'))
> +
> +if __name__ == "__main__":
> +    main(sys.argv)

Wow, python really makes this kind of task clunky compared to shell...

This doesn't seem to be the same logic as the original shell.
I'm not too familiar with python, but:
 * the shell script doesn't run git if pkgversion is not the empty string
 * the shell script doesn't run git unless the .git directory exists
If these are intentional behaviour changes you should mention
them in the commit message.

Also worth mentioning that you're fixing the bug in the shell
script where we ignore the output from git (the intention was
to ignore a failure from git but otherwise to keep its output;
this patch:
https://patchew.org/QEMU/20200929143654.518157-1-marcandre.lureau@redhat.com/
is the fix for that in the existing shell script).

> diff --git a/scripts/qemu-version.sh b/scripts/qemu-version.sh
> deleted file mode 100755
> index 03128c56a2..0000000000
> --- a/scripts/qemu-version.sh
> +++ /dev/null
> @@ -1,25 +0,0 @@
> -#!/bin/sh
> -
> -set -eu
> -
> -dir="$1"
> -pkgversion="$2"
> -version="$3"
> -
> -if [ -z "$pkgversion" ]; then
> -    cd "$dir"
> -    if [ -e .git ]; then
> -        pkgversion=$(git describe --match 'v*' --dirty | echo "")
> -    fi
> -fi
> -
> -if [ -n "$pkgversion" ]; then
> -    fullversion="$version ($pkgversion)"
> -else
> -    fullversion="$version"
> -fi
> -
> -cat <<EOF
> -#define QEMU_PKGVERSION "$pkgversion"
> -#define QEMU_FULL_VERSION "$fullversion"
> -EOF

thanks
-- PMM