From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bruce Richardson <bruce.richardson@intel.com>
Subject: Re: [PATCH v6 2/8] rte_rwlock.h: gcc8 sign conversion
 warnings
Date: Mon, 21 May 2018 13:10:09 +0100
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To: Andy Green <andy@warmcat.com>
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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>