[pacman-dev] [PATCH] Add a helper macro to free() dload_payload structure

[Anatol Pomozov]

Hi

On Sun, Apr 26, 2020 at 7:18 PM Allan McRae <allan at archlinux.org> wrote:
>
> On 27/4/20 11:54 am, Anatol Pomozov wrote:
> > Hi
> >
> > On Sun, Apr 26, 2020 at 4:54 PM Allan McRae <allan at archlinux.org> wrote:
> >>
> >> On 24/4/20 2:40 pm, Anatol Pomozov wrote:
> >>> It frees all the dynamically allocated fields plus the struct itself
> >>>
> >>
> >> How many times will you use this?   Across how many functions?
> >
> > Currently my tree uses this macro 6 times. All of them in error
> > codepath like this one:
> >
> > STRDUP(payload->fileurl, url,
> >     DLOAD_PAYLOAD_FREE(payload); GOTO_ERR(handle, ALPM_ERR_MEMORY, err));
> >
> > An alternative to it is to inline DLOAD_PAYLOAD_FREE() macro into the
> > STRDUP parameter.
> > But it might look too verbose in this use-case:
> >
> > STRDUP(payload->fileurl, url,
> >     _alpm_dload_payload_reset(payload);  FREE(payload);
> >     GOTO_ERR(handle, ALPM_ERR_MEMORY, err));
> >
>
> OK - that seems fine.
>
> >> We usually #unset defines not used globally too.
> >
> > I am not sure I understand this #unset requirement. Could you please
> > give an example how it should work here?
> >
>
> I was trying to establish of the usage of this define would be all in
> one function.  Or is it needed in multiple.
>
> If it was in one function, we can #define it in the function and #undef
> it at the end.  There are examples in libalpm/hook.c and util.c .

Currently this macro is used in 3 different files:

lib/libalpm/be_sync.c:192:
DLOAD_PAYLOAD_FREE(payload); GOTO_ERR(handle, ALPM_ERR_MEMORY,
cleanup));
lib/libalpm/be_sync.c:208:
DLOAD_PAYLOAD_FREE(sig_payload); GOTO_ERR(handle, ALPM_ERR_MEMORY,
cleanup));
lib/libalpm/dload.c:825:
DLOAD_PAYLOAD_FREE(payload); GOTO_ERR(handle, ALPM_ERR_MEMORY, err));
lib/libalpm/dload.h:59:#define DLOAD_PAYLOAD_FREE(payload) { \
lib/libalpm/sync.c:741:
DLOAD_PAYLOAD_FREE(payload); GOTO_ERR(handle, ALPM_ERR_MEMORY,
finish));
lib/libalpm/sync.c:743:
DLOAD_PAYLOAD_FREE(payload); GOTO_ERR(handle, ALPM_ERR_MEMORY,
finish));
lib/libalpm/sync.c:766:
DLOAD_PAYLOAD_FREE(sig_payload); GOTO_ERR(handle, ALPM_ERR_MEMORY,
finish));