[LLVMdev] Is LowerInvoke's "-enable-correct-eh-support" option unused?

[Anton Korobeynikov]

Right. So it can be safely removed.

On Mon, Mar 10, 2014 at 11:06 PM, Jim Grosbach <grosbach at apple.com> wrote:
> IIRC, the LowerInvoke pass was for the C backend and is at least mostly
> vestigial now. The SjLj style EH it did was very different from what the
> SjLjEHPrepare pass implements.
> -Jim
> On Mar 7, 2014, at 5:12 PM, Mark Seaborn <mseaborn at chromium.org> wrote:
>
> On 6 March 2014 18:09, Mark Seaborn <mseaborn at chromium.org> wrote:
>>
>> LowerAtomic "lowers atomic intrinsics to non-atomic form for use in a
>> known non-preemptible environment".  LowerInvoke strips out exception
>> handling by converting invokes to calls, so that landingpads, resumes, etc.
>> become dead and can be removed by a later pass.
>>
>> (As an aside, LowerInvoke has an option for using SJLJ exception handling,
>> but that option appears to be unused and replaced by
>> lib/CodeGen/SjLjEHPrepare.cpp.)
>
>
> On that topic, should LowerInvoke's "-enable-correct-eh-support" option be
> removed, since it appears to be unused?  If so, I can prepare a patch.
>
> This option lowers exception handling to setjmp/longjmp, but it uses a
> variable called "llvm.sjljeh.jblist" for the list of saved setjmp frames.
> I've not found any code that looks at that list to implement throwing an
> exception.  It looks like this was replaced by SjLjEHPrepare a long time
> ago.
>
> Cheers,
> Mark
>
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>



-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University