Re: RFA (libstdc++): PATCH to implement C++17 over-aligned new

[Christophe Lyon <christophe.lyon@linaro.org>]

On 10 September 2016 at 08:59, Christophe Lyon
<christophe.lyon@linaro.org> wrote:
> On 9 September 2016 at 23:20, Jason Merrill <jason@redhat.com> wrote:
>> On Thu, Sep 8, 2016 at 7:06 AM, Jonathan Wakely <jwakely@redhat.com> wrote:
>>> On 08/09/16 09:10 +0200, Marc Glisse wrote:
>>>>
>>>> Do we want a generic fallback implementation (similar to
>>>> gcc/config/i386/gmm_malloc.h)? A windows version with _aligned_malloc /
>>>> _aligned_free would also be possible.
>>>
>>> Making it work for MinGW would be nice.
>>
>> OK, this is what I'm checking in; could someone test it on MinGW?
>>
>> Jason
>
> Hi Jason,
>
> I'm seeing problems on arm*linux: the tests aligned-new[1235].C fail to link:
> aligned-new5.C:(.text+0x14): undefined reference to `operator
> new(unsigned int, std::align_val_t)'
>
>
> On aarch64*-elf and arm-eabi (using newlib), I'm seeing:
> /gccsrc/libstdc++-v3/libsupc++/new_opa.cc:66: undefined reference to
> `aligned_alloc'
>
> Am I missing something in my setup?
>

I'm seeing an additional problem: to GCC build is broken after this
commit for target arm-none-eabi (using default cpu):
/home/christophe.lyon/src/GCC/sources/gcc-fsf/reg-240062/libstdc++-v3/libsupc++/new_opant.cc:
In function 'void* operator new(std::size_t, std::align_val_t, const
std::nothrow_t&)':
/home/christophe.lyon/src/GCC/sources/gcc-fsf/reg-240062/libstdc++-v3/libsupc++/new_opant.cc:33:3:
error: '__try' was not declared in this scope
   __try
   ^~~~~
/home/christophe.lyon/src/GCC/sources/gcc-fsf/reg-240062/libstdc++-v3/libsupc++/new_opant.cc:37:11:
error: expected primary-expression before '...' token
   __catch(...)
           ^~~
/home/christophe.lyon/src/GCC/sources/gcc-fsf/reg-240062/libstdc++-v3/libsupc++/new_opant.cc:37:3:
error: '__catch' was not declared in this scope
   __catch(...)
   ^~~~~~~
/home/christophe.lyon/src/GCC/sources/gcc-fsf/reg-240062/libstdc++-v3/libsupc++/new_opant.cc:41:1:
warning: no return statement in function returning non-void
[-Wreturn-type]
 }
 ^
/home/christophe.lyon/src/GCC/sources/gcc-fsf/reg-240062/libstdc++-v3/libsupc++/new_opant.cc:30:26:
warning: unused parameter 'sz' [-Wunused-parameter]
 operator new(std::size_t sz, std::align_val_t al, const std::nothrow_t&)
                          ^~
/home/christophe.lyon/src/GCC/sources/gcc-fsf/reg-240062/libstdc++-v3/libsupc++/new_opant.cc:30:47:
warning: unused parameter 'al' [-Wunused-parameter]
 operator new(std::size_t sz, std::align_val_t al, const std::nothrow_t&)
                                               ^~
make[4]: *** [new_opant.lo] Error 1
make[4]: Leaving directory
`/home/christophe.lyon/src/GCC/builds/gcc-fsf-reg-240062/obj-arm-none-eabi/gcc3/arm-none-eabi/libstdc++-v3/libsupc++'

Let me know if you need more details.

Thanks,

Christophe


> Thanks,
>
> Christophe