[LLVMdev] Exception Handling Rewrite Branch

[Chris Lattner]

On Jul 27, 2011, at 1:08 AM, Bill Wendling wrote:

>>> Progress Report:
>>> 
>>> 	I created the two new instructions: landingpad and resume. Hand-modified code can run through the assembler and disassembler and emit the same code. The verifier can verify basic properties of the landingpad instruction.
>> 
>> Hi Bill,
>> 
>> Any reason to do this on a branch?  Why can't the patches go into mainline?
>> 
> 
> Hi Chris,
> 
> Some of the changes (like the inliner changes) are going to break the old EH way of doing things. The front-ends will need to change over to the new EH scheme. And they won't want to change over until things are finished. It's a bit of a chicken-and-egg thing. I figured that doing this on a branch first and then outlining how to change the front-ends and/or create an Auto-upgrade tool would be the best course of action.

I would greatly prefer for you to implement the new instructions in mainline, and add the new inliner logic (under a flag if need-be).  There should be no breakage for existing code until the frontends switch to generating the new EH stuff.  This can also be done under a flag in clang for example.

-Chris