Re: lib/atomic64_test.c:217:9: error: implicit declaration of function 'atomic64_dec_if_positive'

From: Vineet Gupta
Date: Mon Oct 10 2016 - 12:25:39 EST


Hi Andrew / Peter,

On 10/09/2016 07:37 AM, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: b66484cd74706fa8681d051840fe4b18a3da40ff
> commit: 51a021244b9d579be6b4f8c15c493a76deb2a79e atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
> date: 2 days ago
> config: frv-allmodconfig (attached as .config)
> compiler: frv-linux-gcc (GCC) 6.2.0
> reproduce:
> wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> git checkout 51a021244b9d579be6b4f8c15c493a76deb2a79e
> # save the attached .config to linux build tree
> make.cross ARCH=frv
>
> All errors (new ones prefixed by >>):
>
> In file included from include/linux/init.h:4:0,
> from lib/atomic64_test.c:14:
> lib/atomic64_test.c: In function 'test_atomic64':
> lib/atomic64_test.c:208:9: error: implicit declaration of function 'atomic64_add_unless' [-Werror=implicit-function-declaration]
> BUG_ON(atomic64_add_unless(&v, one, v0));

FWIW, this error was not introduced by my patch. It seems on FRV atomic64 self
tests were never enabled and thus the breakage was not noticed. I took today's
upstream linus tree, reverted my patch and still see this error. There are

Should we make ATOMIC64_SELFTEST depend on !FRV - or do we prefer adding the
missing primitives to seeming orphan arch ? I took a quick look at their atomic.h
and it seems non trivial given my frv foo !

> ^
> include/linux/compiler.h:168:42: note: in definition of macro 'unlikely'
> # define unlikely(x) __builtin_expect(!!(x), 0)
> ^
> lib/atomic64_test.c:208:2: note: in expansion of macro 'BUG_ON'
> BUG_ON(atomic64_add_unless(&v, one, v0));
> ^~~~~~
>>> lib/atomic64_test.c:217:9: error: implicit declaration of function 'atomic64_dec_if_positive' [-Werror=implicit-function-declaration]
> BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
> ^
> include/linux/compiler.h:168:42: note: in definition of macro 'unlikely'
> # define unlikely(x) __builtin_expect(!!(x), 0)
> ^
> lib/atomic64_test.c:217:2: note: in expansion of macro 'BUG_ON'
> BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
> ^~~~~~
> lib/atomic64_test.c:230:10: error: implicit declaration of function 'atomic64_inc_not_zero' [-Werror=implicit-function-declaration]
> BUG_ON(!atomic64_inc_not_zero(&v));
> ^
> include/linux/compiler.h:168:42: note: in definition of macro 'unlikely'
> # define unlikely(x) __builtin_expect(!!(x), 0)
> ^
> lib/atomic64_test.c:230:2: note: in expansion of macro 'BUG_ON'
> BUG_ON(!atomic64_inc_not_zero(&v));
> ^~~~~~
> cc1: some warnings being treated as errors
>
> vim +/atomic64_dec_if_positive +217 lib/atomic64_test.c
>
> 978e5a36 Boqun Feng 2015-11-04 202 DEC_RETURN_FAMILY_TEST(64, v0);
> 86a89380 Luca Barbieri 2010-02-24 203
> 978e5a36 Boqun Feng 2015-11-04 204 XCHG_FAMILY_TEST(64, v0, v1);
> 978e5a36 Boqun Feng 2015-11-04 205 CMPXCHG_FAMILY_TEST(64, v0, v1, v2);
> 86a89380 Luca Barbieri 2010-02-24 206
> 86a89380 Luca Barbieri 2010-02-24 207 INIT(v0);
> 9efbcd59 Luca Barbieri 2010-03-01 @208 BUG_ON(atomic64_add_unless(&v, one, v0));
> 86a89380 Luca Barbieri 2010-02-24 209 BUG_ON(v.counter != r);
> 86a89380 Luca Barbieri 2010-02-24 210
> 86a89380 Luca Barbieri 2010-02-24 211 INIT(v0);
> 9efbcd59 Luca Barbieri 2010-03-01 212 BUG_ON(!atomic64_add_unless(&v, one, v1));
> 86a89380 Luca Barbieri 2010-02-24 213 r += one;
> 86a89380 Luca Barbieri 2010-02-24 214 BUG_ON(v.counter != r);
> 86a89380 Luca Barbieri 2010-02-24 215
> 86a89380 Luca Barbieri 2010-02-24 216 INIT(onestwos);
> 86a89380 Luca Barbieri 2010-02-24 @217 BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
> 86a89380 Luca Barbieri 2010-02-24 218 r -= one;
> 86a89380 Luca Barbieri 2010-02-24 219 BUG_ON(v.counter != r);
> 86a89380 Luca Barbieri 2010-02-24 220
>
> :::::: The code at line 217 was first introduced by commit
> :::::: 86a8938078a8bb518c5376de493e348c7490d506 lib: Add self-test for atomic64_t
>
> :::::: TO: Luca Barbieri <luca@xxxxxxxxxxxxxxxxx>
> :::::: CC: H. Peter Anvin <hpa@xxxxxxxxx>
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
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