Re: [PATCH v2 00/19] hashmap bug/safety/ease-of-use fixes

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 29, 2019, 09:22 UTC
Message-ID: <xmqqy2y7ihih.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20190924010324.22619-1-e@80x24.org>

Eric Wong <e@80x24.org> writes:

Show 13 quoted lines

> Patches 1-11 are largely unchanged from the original series with the
> exception of 2, which is new and posted at:
>
> 	https://public-inbox.org/git/20190908074953.kux7zz4y7iolqko4@whir/
>
> 12-17 take further steps to get us away from hashmap_entry being
> the first element, but they're also a bit ugly because __typeof__
> isn't portable
>
> 18-19 finally brings me to the APIs I want to expose without
> relying on __typeof :)
>
> Apologies for the delays, been busy with other stuff...

Thanks. clang version 6.0.1-10 (which is the version I happen to have installed locally) seems to throw a lot of errors like these:

 -- -- --

$ make CC=clang config.o
    CC config.o
config.c:1944:50: error: variable 'entry' is uninitialized when used here [-Werror,-Wuninitialized]
        hashmap_for_each_entry(&cs->config_hash, &iter, entry,
                                                        ^~~~~
./hashmap.h:453:20: note: expanded from macro 'hashmap_for_each_entry'
                                                OFFSETOF_VAR(var, member)); \
                                                             ^~~
./git-compat-util.h:1346:16: note: expanded from macro 'OFFSETOF_VAR'
        ((uintptr_t)&(ptr)->member - (uintptr_t)(ptr))
                      ^~~
./hashmap.h:445:61: note: expanded from macro 'hashmap_iter_first_entry_offset'
        container_of_or_null_offset(hashmap_iter_first(map, iter), offset)
                                                                   ^~~~~~
config.c:1939:34: note: initialize the variable 'entry' to silence this warning
        struct config_set_element *entry;
                                        ^
                                         = NULL
1 error generated.
make: *** [Makefile:2365: config.o] Error 1

 -- -- --

even though gcc seems to be happy with the source.