Re: [PATCH 1/1] builtin/blame.c: constants into bit shift format

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 17, 2019, 07:38 UTC
Message-ID: <xmqqr23b7ref.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <3b4b8e0353d705ea649c9fb608c021b35e6d8f5b.1571250635.git.gitgitgadget@gmail.com>

"Hariom Verma via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 13 quoted lines

> -#define OUTPUT_SHOW_AGE_WITH_COLOR	04000
> +#define OUTPUT_ANNOTATE_COMPAT      (1<<0)
> +#define OUTPUT_LONG_OBJECT_NAME     (1<<1)
> +#define OUTPUT_RAW_TIMESTAMP        (1<<2)
> +#define OUTPUT_PORCELAIN            (1<<3)
> +#define OUTPUT_SHOW_NAME            (1<<4)
> +#define OUTPUT_SHOW_NUMBER          (1<<5)
> +#define OUTPUT_SHOW_SCORE           (1<<6)
> +#define OUTPUT_NO_AUTHOR            (1<<7)
> +#define OUTPUT_SHOW_EMAIL           (1<<8)
> +#define OUTPUT_LINE_PORCELAIN       (1<<9)
> +#define OUTPUT_COLOR_LINE           (1<<10)
> +#define OUTPUT_SHOW_AGE_WITH_COLOR  (1<<11)

For these small shift counts it probably would not matter, but it may be a good discipline to make sure they are treated as constants of an unsigned type (i.e. write them as (1U<<0) etc.). It probably starts to matter when you reach 1<<31 if these are bits stuffed into "unsigned int" on 32-bit arch.

One advantage of octal and hexadecimal notations have is that 0x80000000 is automatically unsigned, IIRC, on such an archtecture.