Re: [PATCH 06/23] builtin/name-rev: fix various trivial memory leaks

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 30, 2024, 15:36 UTC
Message-ID: <xmqqikwmgacm.fsf@gitster.g>
In-Reply-To: <088f730572f0f5aaa8f9640ea35a4687be9094ba.1721995576.git.ps@pks.im>

Patrick Steinhardt <ps@pks.im> writes:

Show 26 quoted lines

> There are several structures that we don't release after
> `cmd_name_rev()` is done. Plug those leaks.
>
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>  builtin/name-rev.c                   | 6 ++++--
>  t/t6007-rev-list-cherry-pick-file.sh | 1 +
>  t/t6120-describe.sh                  | 1 +
>  3 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/name-rev.c b/builtin/name-rev.c
> index 70e9ec4e47..f62c0a36cb 100644
> --- a/builtin/name-rev.c
> +++ b/builtin/name-rev.c
> @@ -677,7 +677,9 @@ int cmd_name_rev(int argc, const char **argv, const char *prefix)
>  				  always, allow_undefined, data.name_only);
>  	}
>  
> -	UNLEAK(string_pool);
> -	UNLEAK(revs);
> +	string_list_clear(&data.ref_filters, 0);
> +	string_list_clear(&data.exclude_filters, 0);
> +	mem_pool_discard(&string_pool, 0);
> +	object_array_clear(&revs);
>  	return 0;
>  }

You, originally these "we know we are at the very end of the process, so _exit() will take care of releasing the resources" was a very much deliberate, and in a sense, cmd_describe() calling to this function as the last thing to do was still in the same spirit, but it was not a hygiene thing to do.

In the longer term, we would want to make a major part of the body of this "main" function into a reusable library-ish function, which will be called the desribe and name-rev command implementations, and when that happens, these fixes would move together to that library-ish function.

Looking good.