On 9 August 2018 at 00:17, Stefan Beller <sbeller@xxxxxxxxxx> wrote:
> A string list can be used as a stack, but should we? A later patch shows
> how useful this will be.
>
> Signed-off-by: Stefan Beller <sbeller@xxxxxxxxxx>
> ---
> string-list.c | 8 ++++++++
> string-list.h | 6 ++++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/string-list.c b/string-list.c
> index 9f651bb4294..ea80afc8a0c 100644
> --- a/string-list.c
> +++ b/string-list.c
> @@ -80,6 +80,14 @@ void string_list_remove(struct string_list *list, const char *string,
> }
> }
>
> +struct string_list_item *string_list_pop(struct string_list *list)
> +{
> + if (list->nr == 0)
> + return 0;
return NULL, not 0.
> +
> + return &list->items[--list->nr];
> +}
> +
> +/**
> + * Returns the last item inserted and removes it from the list.
> + * If the list is empty, return NULL.
> + */
> +struct string_list_item *string_list_pop(struct string_list *list);
> +
The memory ownership is now with the caller. That is, the caller needs
to check/know `list->strdup_strings` and know `free_util` to be able to
properly free all memory.
OTOH, the pointer returned by this function is only guaranteed to be
valid until you start inserting into the list (well, you can do one
insertion per pop without worrying, but that's quite detailed
implementation knowledge).
Maybe these caveats should be documented, or is a hint that this
`_pop()` is not so nice to have after all, but let's see what happens in
the later patches...
Martin
