Re: [PATCH v2 1/2] Fix nonnull errors reported by UBSAN with GCC 7.

["René Scharfe" <l.s.r@web.de>]

Am 06.04.2017 um 11:52 schrieb Martin Liška:
> I'm sending (v2), where I updated commit message and wrapped 2 problematic
> places to newly introduced macros that do the check. Follow-up patch can
> change usages of memcpy and memove.

> diff --git a/apply.c b/apply.c
> index e6dbab26a..eacca29fa 100644
> --- a/apply.c
> +++ b/apply.c
> @@ -2802,9 +2802,9 @@ static void update_image(struct apply_state *state,
>  			img->line + applied_pos + preimage_limit,
>  			(img->nr - (applied_pos + preimage_limit)) *
>  			sizeof(*img->line));
> -	memcpy(img->line + applied_pos,
> -	       postimage->line,
> -	       postimage->nr * sizeof(*img->line));
> +	MEMCPY(img->line + applied_pos,
> +		postimage->line,
> +		postimage->nr * sizeof(*img->line));

Using the existing macro COPY_ARRAY would yield a nicer result:

	COPY_ARRAY(img->line + applied_pos, postimage->line, postimage->nr);

>  	if (!state->allow_overlap)
>  		for (i = 0; i < postimage->nr; i++)
>  			img->line[applied_pos + i].flag |= LINE_PATCHED;
> diff --git a/builtin/ls-files.c b/builtin/ls-files.c
> index d449e46db..7caeeb6a6 100644
> --- a/builtin/ls-files.c
> +++ b/builtin/ls-files.c
> @@ -391,7 +391,7 @@ static void prune_cache(const char *prefix, size_t prefixlen)
>  		}
>  		last = next;
>  	}
> -	memmove(active_cache, active_cache + pos,
> +	MEMMOVE(active_cache, active_cache + pos,
>  		(last - pos) * sizeof(struct cache_entry *));
>  	active_nr = last - pos;
>  }

Perhaps we should add MOVE_ARRAY to complement COPY_ARRAY.

René