Re: [PATCH v2 08/32] Add new overload of dwarf5_djb_hash

[Simon Marchi <simark@simark.ca>]

On 2021-11-04 2:08 p.m., Tom Tromey wrote:
> This adds a new overload of dwarf5_djb_hash.  This is used in
> subsequent patches.
> ---
>  gdb/dwarf2/index-common.c | 15 +++++++++++++++
>  gdb/dwarf2/index-common.h |  4 ++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/gdb/dwarf2/index-common.c b/gdb/dwarf2/index-common.c
> index 1c02730a3fe..4bad82218c2 100644
> --- a/gdb/dwarf2/index-common.c
> +++ b/gdb/dwarf2/index-common.c
> @@ -54,3 +54,18 @@ dwarf5_djb_hash (const char *str_)
>      hash = hash * 33 + tolower (c);
>    return hash;
>  }
> +
> +/* See dwarf-index-common.h.  */
> +
> +uint32_t
> +dwarf5_djb_hash (gdb::string_view str)
> +{
> +  /* Note: tolower here ignores UTF-8, which isn't fully compliant.
> +     See http://dwarfstd.org/ShowIssue.php?issue=161027.1.  */
> +
> +  uint32_t hash = 5381;
> +  size_t len = str.length ();
> +  for (size_t i = 0; i < len; ++i)
> +    hash = hash * 33 + tolower (str[i] & 0xff);
> +  return hash;
> +}

For bonus points, you could iterate using:

  for (char c : str)

... unless you see a good reason not to.

Simon