Re: [PATCH] zlib.c: use size_t for size
- From
Ramsay Jones <ramsay@ramsayjones.plus.com>
- Date
- Oct 12, 2018, 23:23 UTC
- Message-ID
- <61d49c5f-826f-f28b-8eac-84a5abfab0ee@ramsayjones.plus.com>
- In-Reply-To
- <nycvar.QRO.7.76.6.1810121733560.561@tvgsbejvaqbjf.bet>
On 12/10/18 16:34, Johannes Schindelin wrote:
Show 68 quoted lines
> Hi Junio,
>
> On Fri, 12 Oct 2018, Junio C Hamano wrote:
>
>> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
>>
>>> Hi Junio,
>>>
>>> On Fri, 12 Oct 2018, Junio C Hamano wrote:
>>>
>>>> From: Martin Koegler <martin.koegler@chello.at>
>>>> Date: Thu, 10 Aug 2017 20:13:08 +0200
>>>>
>>>> Signed-off-by: Martin Koegler <martin.koegler@chello.at>
>>>> Signed-off-by: Junio C Hamano <gitster@pobox.com>
>>>> ---
>>>>
>>>> * I made minimal adjustments to make the change apply to today's
>>>> codebase. I still find some choices and mixing of off_t and
>>>> size_t done by the patch a bit iffy, and some arith may need to
>>>> become st_addX(). Extra set of eyes are very much appreciated.
>>>>
>>>> builtin/pack-objects.c | 10 +++++-----
>>>> cache.h | 10 +++++-----
>>>> pack-check.c | 6 +++---
>>>> pack.h | 2 +-
>>>> packfile.h | 2 +-
>>>> wrapper.c | 8 ++++----
>>>> zlib.c | 8 ++++----
>>>> 7 files changed, 23 insertions(+), 23 deletions(-)
>>>>
>>>> diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
>>>> index e6316d294d..b9ca04eb8a 100644
>>>> --- a/builtin/pack-objects.c
>>>> +++ b/builtin/pack-objects.c
>>>> @@ -266,15 +266,15 @@ static void copy_pack_data(struct hashfile *f,
>>>> struct packed_git *p,
>>>> struct pack_window **w_curs,
>>>> off_t offset,
>>>> - off_t len)
>>>> + size_t len)
>>>> {
>>>> unsigned char *in;
>>>> - unsigned long avail;
>>>> + size_t avail;
>>>>
>>>> while (len) {
>>>> in = use_pack(p, w_curs, offset, &avail);
>>>> if (avail > len)
>>>
>>> Do we have to be careful to handle sizeof(off_t) != sizeof(size_t) here? I
>>> guess we would receive a compiler warning about different sizes in that
>>> case, but it makes me worry.
>>
>> Yup, you just said exactly the same thing as I already said in the
>> part you quoted. I still find the mixed use of off_t and size_t in
>> this patch iffy, and that was the secondary reason why the patch was
>> kept in the stalled state for so long. The primary reason was that
>> nobody tried to dust it off and reignite the topic so far---which I
>> am trying to correct, but as I said, this is just minimally adjusted
>> to today's codebase, without any attempt to improve relative to the
>> original patch.
>>
>> I think we are in agreement in that this is not making things worse,
>> as we are already in the mixed arith territory before this patch.
>
> I will *try* to find the time to audit this some more, then. Maybe next
> week, maybe the one afterwards... ;-)This fails to compile on 32-bit Linux. The patch given below is what I used to get git to build on 32-bit Linux (and it even passes the tests).
I haven't even given the off_t -> size_t issue any thought, but I suspect that will have to change as well. Anyway, I have no more time tonight ...
ATB, Ramsay Jones
-- >8 -- Subject: [PATCH] zlib: minimum fix-up on 32-bit linux
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com> --- builtin/pack-objects.c | 3 ++- packfile.c | 16 ++++++++-------- packfile.h | 2 +- 3 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index 7e693071b..cc11a0426 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -2002,7 +2002,8 @@ unsigned long oe_get_size_slow(struct packing_data *pack, struct pack_window *w_curs; unsigned char *buf; enum object_type type; - unsigned long used, avail, size; + size_t used, avail; + unsigned long size; if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) { read_lock(); diff --git a/packfile.c b/packfile.c index f2850a00b..7571ac988 100644 --- a/packfile.c +++ b/packfile.c @@ -585,7 +585,7 @@ static int in_window(struct pack_window *win, off_t offset) unsigned char *use_pack(struct packed_git *p, struct pack_window **w_cursor, off_t offset, - unsigned long *left) + size_t *left) { struct pack_window *win = *w_cursor; @@ -1034,19 +1034,19 @@ struct list_head *get_packed_git_mru(struct repository *r) return &r->objects->packed_git_mru; } -unsigned long unpack_object_header_buffer(const unsigned char *buf, - unsigned long len, enum object_type *type, unsigned long *sizep) +size_t unpack_object_header_buffer(const unsigned char *buf, + size_t len, enum object_type *type, unsigned long *sizep) { unsigned shift; - unsigned long size, c; - unsigned long used = 0; + size_t size, c; + size_t used = 0; c = buf[used++]; *type = (c >> 4) & 7; size = c & 15; shift = 4; while (c & 0x80) { - if (len <= used || bitsizeof(long) <= shift) { + if (len <= used || bitsizeof(size_t) <= shift) { error("bad object header"); size = used = 0; break; @@ -1104,8 +1104,8 @@ int unpack_object_header(struct packed_git *p, unsigned long *sizep) { unsigned char *base; - unsigned long left; - unsigned long used; + size_t left; + size_t used; enum object_type type; /* use_pack() assures us we have [base, base + 20) available diff --git a/packfile.h b/packfile.h index 1fb482424..e8bf11b62 100644 --- a/packfile.h +++ b/packfile.h @@ -132,7 +132,7 @@ extern off_t find_pack_entry_one(const unsigned char *sha1, struct packed_git *) extern int is_pack_valid(struct packed_git *); extern void *unpack_entry(struct repository *r, struct packed_git *, off_t, enum object_type *, unsigned long *); -extern unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep); +extern size_t unpack_object_header_buffer(const unsigned char *buf, size_t len, enum object_type *type, unsigned long *sizep); extern unsigned long get_size_from_delta(struct packed_git *, struct pack_window **, off_t); extern int unpack_object_header(struct packed_git *, struct pack_window **, off_t *, unsigned long *);
-- 2.19.0