Re: [PATCH] C++: target attribute - local decl

[Jason Merrill <jason@redhat.com>]

On 3/2/21 5:34 AM, Martin Liška wrote:
> On 3/1/21 8:58 PM, Jason Merrill wrote:
>> On 3/1/21 11:59 AM, Martin Liška wrote:
>>> On 3/1/21 5:36 PM, Jason Merrill wrote:
>>>> On 3/1/21 7:43 AM, Martin Liška wrote:
>>>>> On 2/22/21 11:53 PM, Jason Merrill wrote:
>>>>>> The problem seems to be with the handling of local decls.  If 
>>>>>> DECL_LOCAL_DECL_P, you need to look at DECL_LOCAL_DECL_ALIAS to 
>>>>>> find the namespace-scope decl.  But then if there is no preceding 
>>>>>> namespace-scope declaration, the new decl created by 
>>>>>> push_local_extern_decl_alias doesn't have a cgraph node, either.  
>>>>>> I guess maybe_function_versions 
>>>>>> also needs to look through DECL_LOCAL_DECL_ALIAS.
>>>>>
>>>>> Ah, I see. Are you sure about the name 'maybe_function_versions'? I 
>>>>> can't find it.
>>>>
>>>> Ah, it's maybe_version_functions, sorry.
>>>
>>> Thanks, I see the function now.
>>> So about your guess:
>>>
>>>> I guess maybe_function_versions also needs to look through 
>>>> DECL_LOCAL_DECL_ALIAS.
>>>
>>> Do you mean maybe_version_functions's argument 'record' should depend 
>>> on DECL_LOCAL_DECL_ALIAS of newdecl/oldddecl
>>> (if present)? Or that DECL_FUNCTION_VERSIONED should be set for 
>>> DECL_LOCAL_DECL_ALIASes of the newdecl/olddecl
>>> function declarations?
>>
>> The latter.
> 
> I see, but will not help us. Problem is that
> #2  0x00000000015d8899 in ix86_get_function_versions_dispatcher 
> (decl=0x7ffff7755000) at 
> /home/marxin/Programming/gcc/gcc/config/i386/i386-features.c:2862
> 
> is called for a declaration for which
> 
> Breakpoint 5, maybe_version_functions (newdecl=<function_decl 
> 0x7ffff7755000 f>, olddecl=<function_decl 0x7ffff7751f00 f>, 
> record=false) at /home/marxin/Programming/gcc/gcc/cp/decl.c:1118
> 
> is called with record=false. So that cgraph_node is not created for it.
> 
> Or is a possible solution that get_function_version_dispatcher should 
> look through the DECL_LOCAL_DECL_ALIAS?

Yes, I was thinking both that function and maybe_version_functions.

Jason