Re: [PATCH] decodetree: Open files with encoding='utf-8'

[Peter Maydell]

On Fri, 8 Jan 2021 at 15:16, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>
> When decodetree.py was added in commit 568ae7efae7, QEMU was
> using Python 2 which happily reads UTF-8 files in text mode.
> Python 3 requires either UTF-8 locale or an explicit encoding
> passed to open(). Now that Python 3 is required, explicit
> UTF-8 encoding for decodetree sources.
>
> This fixes:
>
>   $ /usr/bin/python3 scripts/decodetree.py test.decode
>   Traceback (most recent call last):
>     File "scripts/decodetree.py", line 1397, in <module>
>       main()
>     File "scripts/decodetree.py", line 1308, in main
>       parse_file(f, toppat)
>     File "scripts/decodetree.py", line 994, in parse_file
>       for line in f:
>     File "/usr/lib/python3.6/encodings/ascii.py", line 26, in decode
>       return codecs.ascii_decode(input, self.errors)[0]
>   UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 80:
>   ordinal not in range(128)
>
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  scripts/decodetree.py | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/scripts/decodetree.py b/scripts/decodetree.py
> index 47aa9caf6d1..fa40903cff1 100644
> --- a/scripts/decodetree.py
> +++ b/scripts/decodetree.py
> @@ -1304,7 +1304,7 @@ def main():
>
>      for filename in args:
>          input_file = filename
> -        f = open(filename, 'r')
> +        f = open(filename, 'r', encoding='utf-8')
>          parse_file(f, toppat)
>          f.close()

Should we also be opening the output file explicitly as
utf-8 ? (How do we say "write to sys.stdout as utf-8" for
the case where we're doing that?)

thanks
-- PMM