Re: [PATCH][wwwdocs] gcc-13: Add loongarch '-mexplicit-relocs' support

[Lulu Cheng <chenglulu@loongson.cn>]

在 2022/7/26 下午8:01, Xi Ruoyao 写道:
> On Tue, 2022-07-26 at 19:42 +0800, Lulu Cheng wrote:
>
>> 在 2022/7/26 下午5:44, Xi Ruoyao 写道:
>>>> +  whether the <code>la.*</code> macro instructions will be generated when
>>>> +  loading symbolic addresses.
>>>> +  This feature requires binutils version 2.40 or later. If you want to use the
>>>> +  older version of bintuils, add compiler parameters
>>>> +  <code>-mno-explicit-relocs</code> at compile time.
>>> Does it mean we need to make sure GCC 13 released after binutils-2.40?
>>> binutils-2.39 release branch is already created and it's now explicitly
>>> "no new feature" so a backport seems impossible...
>> Do you think it's okay if we don't write Binutils version restrictions
>> now and wait until Binutils code is released to annotate?
> I think you can just put Binutils 2.40 here.  GCC 13 will be released in
> Apr or May 2023, and Binutils-2.40 will be released in Jan or Feb 2023
> (if no bad thing happens), so my previous concern is actually not a
> problem.
>
> Maybe we can add a check in gcc/configure.ac to see if gcc_cv_ld
> supports %got_pc_hi20 and adjust the default for -m[no]-explicit-relocs?

I think this is a good way, I'll look at adding a check.

>> Should we indicate that our .eh_frame section format has changed?
> I don't really understand C++ exception handling, so: does the change
> breaks something?  For example, if foo links to libbar, libbar is built
> with GCC 12 (or vice versa), would an exception thrown from libbar
> properly caught by foo?
>
> Generally changes.html is for compiler users (instead of developers),
> and I believe at least 90% of users (including I) don't know the
> potential consequences from a .eh_frame format change.  So it's better
> to describe the breakage and possible workaround here.  If nothing will
> be broken, we can just skip the change in changes.html.
>
>
I'm looking to see if I can find a test that can verify the

compatibility or incompatibility before and after the modification.


Thanks!:-)