gcc-4.7-20111022 fails to build on PA-RISC

[Jonathan Wakely]

On 29 October 2011 19:01, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> What does the definition of _pthread_fastlock on line 34 of
> /usr/include/bits/pthreadtypes.h look like?
>

Don't worry, I foudn the definition on an hppa-linux machine, and can
reproduce the problem even with the latest std::mutex code

e.g.

typedef volatile struct {
    int lock[4];
} __attribute__ ((aligned(16))) __atomic_lock_t;

struct _pthread_fastlock
{
    __atomic_lock_t __spinlock;
};

typedef struct {
    struct _pthread_fastlock lock;
} pthread_mutex_t;

struct mutex {
  pthread_mutex_t m = { };
  mutex() = default;
};

int main()
{
  mutex mx;
}

The problem is that the mutex contains a volatile type and can't be
copied by the implicit-declared copy constructor.

I'll have to look into this further tomorrow to see if it's a G++
problem or something we need to work around in the library.