49f1eb3b34
Using gcc-11 (or 12) to compile refs.o with -O3 results in:
In file included from hashmap.h:4,
from cache.h:6,
from refs.c:5:
In function ‘oidcpy’,
inlined from ‘ref_transaction_add_update’ at refs.c:1065:3,
inlined from ‘ref_transaction_update’ at refs.c:1094:2,
inlined from ‘ref_transaction_verify’ at refs.c:1132:9:
hash.h:262:9: warning: argument 2 null where non-null expected [-Wnonnull]
262 | memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from git-compat-util.h:177,
from cache.h:4,
from refs.c:5:
refs.c: In function ‘ref_transaction_verify’:
/usr/include/string.h:43:14: note: in a call to function ‘memcpy’ declared ‘nonnull’
43 | extern void *memcpy (void *__restrict __dest, const void *__restrict __src,
| ^~~~~~
That call to memcpy() is in a conditional block that requires
REF_HAVE_NEW to be set. But in ref_transaction_update(), we make sure it
isn't set coming in:
if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
and then only set it if the variable isn't NULL:
flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
So it should be impossible to reach that memcpy() with a NULL oid. But
for whatever reason, gcc doesn't accept that hitting the BUG() means we
won't go any further, even though it's marked with the noreturn
attribute. And the conditional is correct; ALLOWED_FLAGS doesn't contain
HAVE_NEW or HAVE_OLD, and you can even simplify it to check for those
flags explicitly and the compiler still complains.
We can work around this by just clearing the disallowed flags
explicitly. This should be a noop because of the BUG() check, but it
makes the compiler happy.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
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See Documentation/gittutorial.txt to get started, then see
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- random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
- "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks