Re: lib/49989: libc++ fails to build with g++ 5.1 due to libpthread volatiles

[Antti Kantee <pooka%iki.fi@localhost>]

Thanks, Christos!

I'll ask the submitter to test.

On 20/06/15 16:05, Christos Zoulas wrote:
>   Index: pthread_types.h
>   ===================================================================
>   RCS file: /cvsroot/src/lib/libpthread/pthread_types.h,v
>   retrieving revision 1.13
>   diff -u -u -r1.13 pthread_types.h
>   --- pthread_types.h	2 Aug 2008 19:46:30 -0000	1.13
>   +++ pthread_types.h	20 Jun 2015 16:03:04 -0000
>   @@ -84,6 +84,23 @@
>    };
>
>    /*
>   + * libc++ expects to be using PTHREAD_MUTEX_INITIALIZER as a member
>   + * initializer. This does not work for volatile types. Since c++
>   + * does not touch the guts of those types, we redefine them as non-volatile
>   + */
>   +#ifdef __cplusplus
>   +# ifdef __CPU_SIMPLE_LOCK_PAD
>   +#  define __pthread_mutex_spin_t unsigned char
>   +# else
>   +#  define __pthread_mutex_spin_t unsigned int
>   +# endif
>   +# define __pthread_mutex_volatile
>   +#else
>   +# define __pthread_mutex_spin_t pthread_spin_t
>   +# define __pthread_mutex_volatile volatile
>   +#endif
>   +
>   +/*
>     * ptm_owner is the actual lock field which is locked via CAS operation.
>     * This structure's layout is designed to compatible with the previous
>     * version used in SA pthreads.
>   @@ -100,16 +117,16 @@
>    #endif
>    struct	__pthread_mutex_st {
>    	unsigned int	ptm_magic;
>   -	pthread_spin_t	ptm_errorcheck;
>   +	__pthread_mutex_spin_t	ptm_errorcheck;
>    #ifdef __CPU_SIMPLE_LOCK_PAD
>    	uint8_t		ptm_pad1[3];
>    #endif
>   -	pthread_spin_t	ptm_interlock;	/* unused - backwards compat */
>   +	__pthread_mutex_spin_t	ptm_interlock;	/* unused - backwards compat */
>    #ifdef __CPU_SIMPLE_LOCK_PAD
>    	uint8_t		ptm_pad2[3];
>    #endif
>   -	volatile pthread_t ptm_owner;
>   -	pthread_t * volatile ptm_waiters;
>   +	__pthread_mutex_volatile pthread_t ptm_owner;
>   +	pthread_t * __pthread_mutex_volatile ptm_waiters;
>    	unsigned int	ptm_recursed;
>    	void		*ptm_spare2;	/* unused - backwards compat */
>    };