[LLVMdev] Whither exceptions

[Dale Johannesen]

On Dec 20, 2007, at 9:57 AM, Chris Lattner wrote:

> On Thu, 20 Dec 2007, Dale Johannesen wrote:
>> I'm strongly of the opinion that you shouldn't have to say anything  
>> to
>> get EH on targets where it works.
>> -fexceptions is set up like that.
>
> I'm not sure I get what you mean.  gcc defaults to no EH data, you  
> need
> -fexceptions to turn it on.  g++ defaults it to on, because it knows  
> the
> front-end.  You think we should have llc default to EH on when the  
> target
> supports it?

The target and the source language, yes.  I agree it should be off by  
default
for C, so I guess what I want is to encode the -fexceptions value in  
the IR.
People with C++ programs shouldn't need a BE flag to make a fundamental
language feature work.

> Don't all targets support sjlj?

Apparently not, since there were a lot of new passes when I changed
-enable-eh-correct to -enable-eh.  I haven't looked into the sjlj  
implementation
at all though, so I can't say why.