Re: [PATCH v1] msvc: fix non-standard escape sequence in source

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 24, 2018, 18:03 UTC
Message-ID: <xmqq6014zf33.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20180724144249.2857-1-git@jeffhostetler.com>

git@jeffhostetler.com writes:

Show 10 quoted lines

> From: Jeff Hostetler <jeffhost@microsoft.com>
>
> Replace non-standard "\e" escape sequence with "\x1B".
>
> In commit 7a17918c34f4e83982456ffe22d880c3cda5384f a trace message with
> several "\e" escape sequences was added.  This causes a compiler warning
> under MSVC.
>
> According to [1], the "\e" sequence is an extension supported by GCC,
> clang, and tcc.

Good spotting. Please spell it \x1b (or \033 if you are a traditionalist), as it seems nobody in the existing code uses uppercase, according to

    $ git grep -e '\\x[A-F][0-9A-F]' -e '\\x[0-9A-F][A-F]' \*.c

and "\033"  is already used in many places

    $ git grep -e '\\0[0-7][0-7]' \*.c

Show 20 quoted lines

> [1] https://en.wikipedia.org/wiki/Escape_sequences_in_C
>
> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
> ---
>  convert.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/convert.c b/convert.c
> index 56cfe31..52092be 100644
> --- a/convert.c
> +++ b/convert.c
> @@ -335,7 +335,7 @@ static void trace_encoding(const char *context, const char *path,
>  	strbuf_addf(&trace, "%s (%s, considered %s):\n", context, path, encoding);
>  	for (i = 0; i < len && buf; ++i) {
>  		strbuf_addf(
> -			&trace,"| \e[2m%2i:\e[0m %2x \e[2m%c\e[0m%c",
> +			&trace,"| \x1B[2m%2i:\x1B[0m %2x \x1B[2m%c\x1B[0m%c",
>  			i,
>  			(unsigned char) buf[i],
>  			(buf[i] > 32 && buf[i] < 127 ? buf[i] : ' '),