Re: [PATCH 0/4] fix make sparse warning

From: Ramsay Jones <ramsay@ramsayjones.plus.com>
Date: Apr 24, 2020, 16:38 UTC
Message-ID: <4ff17acf-42dc-5a00-bb61-b055144075eb@ramsayjones.plus.com>
In-Reply-To: <20200423235809.GA1949@danh.dev>

On 24/04/2020 00:58, Danh Doan wrote:

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> On 2020-04-24 00:10:25+0100, Ramsay Jones <ramsay@ramsayjones.plus.com> wrote:
>> On 23/04/2020 14:47, Đoàn Trần Công Danh wrote:
>>> It's happened that I tried to run make check on project that support autoconf.
>>
>> I try to ignore autoconf as much as possible, so I don't know why people
> 
> For some reason, people refer to autotools as autohell
> 
>> who use it regularly seem to expect a 'make check' target (is that anything
>> to do with ./config.status --recheck?).
> 
> Because it's autotools's recommendation.
> https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.69/html_node/Basic-Installation.html#Basic-Installation
> https://www.gnu.org/software/automake/manual/automake.html#Standard-Targets

Ah, OK, that explains alot! :D

I have never seen that documented before, so thanks for the reference. Having said that, most all 'autotools' projects I have seen have had an 'make test' target and _not_ 'make check'! (Well, thinking about it, none of those were actual GNU projects - maybe that's the difference).

[snip]

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>> For those interested, the 'too much warnings' on the 'pu' branch looks
>> like (for pu@faf094bf11):
>>
>>   $ make sparse >psp-out 2>&1
>>   $ diff nsp-out psp-out
>>   154a155
>>   >     SP refs/reftable-backend.c
>>   406a408
>>   >     SP t/helper/test-proc-receive.c
>>   447a450,511
>>   >     SP reftable/basics.c
>>   > reftable/basics.c:157:6: warning: symbol 'reftable_malloc_ptr' was not declared. Should it be static?
>>   > reftable/basics.c:158:6: warning: symbol 'reftable_realloc_ptr' was not declared. Should it be static?
>>   > reftable/basics.c:159:6: warning: symbol 'reftable_free_ptr' was not declared. Should it be static?

[snip]

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>>   >     SP reftable/writer.c
>>   > reftable/writer.c:231:31: warning: Using plain integer as NULL pointer
>>   > reftable/writer.c:299:39: warning: Using plain integer as NULL pointer
>>   > reftable/writer.c:347:47: warning: Using plain integer as NULL pointer
>>   > reftable/writer.c:426:31: warning: Using plain integer as NULL pointer
>>   > reftable/writer.c:468:45: warning: Using plain integer as NULL pointer
>>   > reftable/writer.c:584:11: warning: symbol 'debug' was not declared. Should it be static?
>>   >     SP reftable/zlib-compat.c
>>
>> Also, my static-check perl script says the following symbols are not
>> used outside the file which defines them (so they could be marked static):
> 
> All of them are in reftable, and they're catched by `make sparse`,
> too.

Yeah, I didn't even look at the output. ;-)

However, the output from static-check.pl is usually a super-set of the those from sparse - because sparse is really only looking at the declarations (or lack thereof) in one compilation unit. In contrast, static-check.pl looks at all object files to tie up definitions with use (so across compilation units). (which is also why you have to be careful not to leave stale '*.o' files laying around when switching branches).

ATB, Ramsay Jones