8185505: AArch64: Port AOT

[Ningsheng Jian]

> -----Original Message-----
> From: Andrew Haley <aph at redhat.com>
> Sent: Tuesday, April 24, 2018 9:27 PM
> To: Ningsheng Jian <Ningsheng.Jian at arm.com>; Yang Zhang
> <Yang.Zhang at arm.com>; Vladimir Kozlov <vladimir.kozlov at oracle.com>;
> hotspot-dev at openjdk.java.net
> Cc: nd <nd at arm.com>
> Subject: Re: 8185505: AArch64: Port AOT
> 
> On 04/24/2018 06:45 AM, Ningsheng Jian wrote:
> 
> > Specifically for the link error Yang met, since the stub code (not the
> > GOT cases) and the call site are both in .text section, I think it
> > might be helpful to issue warning/error when generating the relocation
> > entry (before the long time linking phase).
> 
> We don't know that the overflow will happen until ink time.
> 

I think we know the overflow for Stub<* functions, since they are local binding symbols and in .text section - the offset to the callsite is known.
Maybe we can put those compiled functions in different sections in .o file, other than all in the same .text section, and let linker to handle the overflow by itself. IIRC, ld will insert veneer code automatically for those out-of-range calls. But if all the code is already in one section, ld could not do that. 

Thanks,
Ningsheng