[dpdk-dev,v6,2/8] rte_rwlock.h: gcc8 sign conversion warnings
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Commit Message
In file included from /projects/lagopus/src/dpdk/
build/include/rte_rwlock.h:12,
from ./mgr/lock.h:24,
from ./mgr/sock_io.c:54:
/projects/lagopus/src/dpdk/build/include/generic/
rte_rwlock.h: In function 'rte_rwlock_read_lock':
/projects/lagopus/src/dpdk/build/include/generic/
rte_rwlock.h:74:12: warning: conversion to 'uint32_t'
{aka 'unsigned int'} from 'int32_t' {aka 'int'} may
change the sign of the result [-Wsign-conversion]
x, x + 1);
^
/projects/lagopus/src/dpdk/build/include/generic/
rte_rwlock.h:74:17: warning: conversion to 'uint32_t'
{aka 'unsigned int'} from 'int' may change the sign
of the result [-Wsign-conversion]
x, x + 1);
~~^~~
/projects/lagopus/src/dpdk/build/include/generic/
rte_rwlock.h: In function 'rte_rwlock_write_lock':
/projects/lagopus/src/dpdk/build/include/generic/
rte_rwlock.h:110:15: warning: unsigned conversion
from 'int' to 'uint32_t' {aka 'unsigned int'}
changes value from '-1' to '4294967295'
[-Wsign-conversion]
0, -1);
^~
Again in this case we are making explicit the exact cast
that was always happening implicitly. The patch does not
change the generated code.
The int32_t temp "x" is required to be signed to detect
a < 0 error condition from the lock status. Afterwards,
it has always been implicitly cast to uint32_t when it
is used in the arguments to rte_atomic32_cmpset()...
gcc8.1 objects to the implicit cast now and requires us
to cast it explicitly.
Fixes: af75078fec ("first public release")
Signed-off-by: Andy Green <andy@warmcat.com>
---
lib/librte_eal/common/include/generic/rte_rwlock.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Comments
On Mon, May 21, 2018 at 10:01:03AM +0800, Andy Green wrote:
> In file included from /projects/lagopus/src/dpdk/
> build/include/rte_rwlock.h:12,
> from ./mgr/lock.h:24,
> from ./mgr/sock_io.c:54:
> /projects/lagopus/src/dpdk/build/include/generic/
> rte_rwlock.h: In function 'rte_rwlock_read_lock':
> /projects/lagopus/src/dpdk/build/include/generic/
> rte_rwlock.h:74:12: warning: conversion to 'uint32_t'
> {aka 'unsigned int'} from 'int32_t' {aka 'int'} may
> change the sign of the result [-Wsign-conversion]
> x, x + 1);
> ^
> /projects/lagopus/src/dpdk/build/include/generic/
> rte_rwlock.h:74:17: warning: conversion to 'uint32_t'
> {aka 'unsigned int'} from 'int' may change the sign
> of the result [-Wsign-conversion]
> x, x + 1);
> ~~^~~
> /projects/lagopus/src/dpdk/build/include/generic/
> rte_rwlock.h: In function 'rte_rwlock_write_lock':
> /projects/lagopus/src/dpdk/build/include/generic/
> rte_rwlock.h:110:15: warning: unsigned conversion
> from 'int' to 'uint32_t' {aka 'unsigned int'}
> changes value from '-1' to '4294967295'
> [-Wsign-conversion]
> 0, -1);
> ^~
>
> Again in this case we are making explicit the exact cast
> that was always happening implicitly. The patch does not
> change the generated code.
>
> The int32_t temp "x" is required to be signed to detect
> a < 0 error condition from the lock status. Afterwards,
> it has always been implicitly cast to uint32_t when it
> is used in the arguments to rte_atomic32_cmpset()...
> gcc8.1 objects to the implicit cast now and requires us
> to cast it explicitly.
>
> Fixes: af75078fec ("first public release")
> Signed-off-by: Andy Green <andy@warmcat.com>
> ---
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
@@ -71,7 +71,7 @@ rte_rwlock_read_lock(rte_rwlock_t *rwl)
continue;
}
success = rte_atomic32_cmpset((volatile uint32_t *)&rwl->cnt,
- x, x + 1);
+ (uint32_t)x, (uint32_t)(x + 1));
}
}
@@ -107,7 +107,7 @@ rte_rwlock_write_lock(rte_rwlock_t *rwl)
continue;
}
success = rte_atomic32_cmpset((volatile uint32_t *)&rwl->cnt,
- 0, -1);
+ 0, (uint32_t)-1);
}
}