[RFC 4/6] ARC: Initial port to glibc

[Vineet Gupta]

On 06/27/2017 02:56 PM, Joseph Myers wrote:
> On Tue, 27 Jun 2017, Vineet Gupta wrote:
> 
>> Signed-off-by: Cupertino Miranda <cmiranda at synopsys.com>
>> Signed-off-by: Vineet Gupta <vgupta at synopsys.com>
> 
> We need ChangeLog entries and copyright assignments, but don't use
> Signed-off-by.

OK !

>> diff --git a/.gitignore b/.gitignore
>> index 07d4a129e5dc..969dabc873d6 100644
>> --- a/.gitignore
>> +++ b/.gitignore
>> @@ -6,6 +6,7 @@
>>   *.bz2
>>   *.rej
>>   *.orig
>> +*.sw*
>>   =*
>>   TAGS
>>   TODO
> 
> I don't think this belongs here.  If it does you'll need to explain
> further.

Right - that was a local change which seeped out. Now removed.

>> diff --git a/sysdeps/arc/Makefile b/sysdeps/arc/Makefile
>> new file mode 100644
>> index 000000000000..b43ae0d0dedf
>> --- /dev/null
>> +++ b/sysdeps/arc/Makefile
>> @@ -0,0 +1,26 @@
>> +# Copyright (C) 1993-2015 Free Software Foundation, Inc.
> 
> All new files should have a descriptive comment before the copyright
> notice.  All copyright notices should use <year>-2017 as dates.

OK !

>> diff --git a/sysdeps/arc/Versions b/sysdeps/arc/Versions
>> new file mode 100644
>> index 000000000000..54ac5e7d1b5f
>> --- /dev/null
>> +++ b/sysdeps/arc/Versions
>> @@ -0,0 +1,13 @@
>> +libc {
>> +  GLIBC_2.24 {
> 
> As a new port, of course use GLIBC_2.26 for minimum symbol version (or
> GLIBC_2.27 if that's when it gets in, etc.), and so for any port-specific
> symbols.

Done !

>> diff --git a/sysdeps/unix/sysv/linux/arc/Versions b/sysdeps/unix/sysv/linux/arc/Versions
>> new file mode 100644
>> index 000000000000..e42c85f57594
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/arc/Versions
>> @@ -0,0 +1,6 @@
>> +libc {
>> +  GLIBC_2.21 {
>> +    _flush_cache;
>> +    cacheflush;
>> +  }
> 
> Same comment on symbol versions applies.

Done !

> 
>> +#define __ASSUME_ACCEPT4_SYSCALL        1
>> +#define __ASSUME_RECVMMSG_SYSCALL       1
>> +#define __ASSUME_SENDMMSG_SYSCALL       1
> 
> This is the default, so you shouldn't need your kernel-features.h file.

Now removed.

> 
>> diff --git a/sysdeps/unix/sysv/linux/arc/ld.abilist b/sysdeps/unix/sysv/linux/arc/ld.abilist
>> new file mode 100644
>> index 000000000000..6001f2e98402
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/arc/ld.abilist
>> @@ -0,0 +1,12 @@
>> +GLIBC_2.24
>> + GLIBC_2.24 A
>> + __libc_memalign F
>> + __libc_stack_end D 0x4
>> + __stack_chk_guard D 0x4
>> + __tls_get_addr F
>> + _dl_mcount F
>> + _r_debug D 0x14
>> + calloc F
>> + free F
>> + malloc F
>> + realloc F
> 
> These ABI lists are in the old format.  You need to regenerate them anyway
> for the increased minimum symbol version.

OK !

> 
>> diff --git a/sysdeps/unix/sysv/linux/arc/shlib-versions b/sysdeps/unix/sysv/linux/arc/shlib-versions
>> new file mode 100644
>> index 000000000000..c4d5d029812d
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/arc/shlib-versions
>> @@ -0,0 +1,2 @@
>> +DEFAULT                 GLIBC_2.21
>> +ld=ld-linux.so.2
> 
> Should be 2.26 (or later).  Consider using an architecture-specific
> dynamic linker name as various other architectures do.

OK ! FWIW, this also ties into gcc defined GLIBC_DYNAMIC_LINKER which needs a 
pairing change as well.

> 
>> diff --git a/sysdeps/unix/sysv/linux/arc/sys/ucontext.h b/sysdeps/unix/sysv/linux/arc/sys/ucontext.h
>> new file mode 100644
>> index 000000000000..37f7f9224853
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/arc/sys/ucontext.h
>> @@ -0,0 +1,40 @@

...

>> +
>> +#ifndef _SYS_UCONTEXT_H
>> +#define _SYS_UCONTEXT_H	1
>> +
>> +#include <features.h>
>> +#include <signal.h>
>> +#include <bits/sigcontext.h>
> 
> I'd expect includes of bits/types/sigset_t.h and bits/types/stack_t.h like
> other versions, but not of signal.h.

Yeah I see that you recently did sweeping changes to same effect. Noted and updated.

> 
>> +typedef struct sigcontext mcontext_t;
> 
> You can avoid this problematic definition for a new architecture, even
> while we're still discussing eliminating it for existing architectures.

So just use struct sigcontext as data type for uc_mcontext ?

> 
>> +/* Userlevel context.  */
>> +typedef struct ucontext
>> +  {
>> +    unsigned long uc_flags;
>> +    struct ucontext *uc_link;
> 
> This is now struct ucontext_t.

Ah I see this was done yesterday on up/master - ok will do !

Thx for taking a quick first pass at the code and providing the comments.

-Vineet