[PATCH] Define GEN_AS_CONST_HEADERS when generating header files [BZ #22792]

[H.J. Lu]

On Wed, Feb 21, 2018 at 7:40 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Tue, Feb 20, 2018 at 11:09 PM, Florian Weimer <fweimer@redhat.com> wrote:
>> On 02/08/2018 06:58 PM, H.J. Lu wrote:
>>>
>>>         [BZ #22792]
>>>         * Makerules ($(common-objpfx)%.h): Pass -DGEN_AS_CONST_HEADERS
>>>         to $(CC).
>>>         * sysdeps/unix/sysv/linux/i386/lowlevellock.h: Include
>>>         <tcb-offsets.h> only if GEN_AS_CONST_HEADERS isn't defined.
>>>         * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Don't include
>>>         <tcb-offsets.h>.
>>
>>
>> It looks to me that a cleaner fix would be to move the definition of the TCB
>> types to a separate header.
>
> I will take a look.

sysdeps/i386/nptl/tcb-offsets.sym has

#include <sysdep.h>
#include <tls.h>
#include <kernel-features.h>

RESULT offsetof (struct pthread, result)
TID offsetof (struct pthread, tid)
CANCELHANDLING offsetof (struct pthread, cancelhandling)
CLEANUP_JMP_BUF offsetof (struct pthread, cleanup_jmp_buf)
MULTIPLE_THREADS_OFFSET offsetof (tcbhead_t, multiple_threads)
SYSINFO_OFFSET offsetof (tcbhead_t, sysinfo)
CLEANUP offsetof (struct pthread, cleanup)
CLEANUP_PREV offsetof (struct _pthread_cleanup_buffer, __prev)
MUTEX_FUTEX offsetof (pthread_mutex_t, __data.__lock)
POINTER_GUARD offsetof (tcbhead_t, pointer_guard)
#ifndef __ASSUME_PRIVATE_FUTEX
PRIVATE_FUTEX offsetof (tcbhead_t, private_futex)
#endif

It covers more than just tcbhead_t.  A separate header file for tcbhead_t
won't help here.

>> The circular dependency is just a cosmetic warning from make, right?
>
> It depends on how unlucky you are.  In one case on a many-core machine
> with make -j60, I had to kill glibc build since it never stopped.
>
>
> --
> H.J.



-- 
H.J.