[LLVMdev] Inlining and exception handling in LLVM and GCC

[Duncan Sands]

Hi John,

On 07/12/10 01:01, John McCall wrote:
> On Dec 6, 2010, at 1:58 PM, Duncan Sands wrote:
>> The poor interaction between exception handling and inlining in LLVM is one of
>> the main motivations for the new exception handling models proposed recently.
>> Here I give my analysis of the origin of the problem in the hope of clarifying
>> the situation.
>
> Your analysis coincides with the analysis I made when implementing EH
> in clang. I decided, however, that in the short term, given the brokenness
> of the IR, I would rather ignore the known bad consequences of emitting
> cleanups as catch-alls than deal with the uncertainties of whether codegen
> could consistently clean up after our broken inliner. I haven't yet regretted
> this choice.

if I changed the inliner so it does its best to find the eh.selector for an
invoke, and propagates the information onto the things it inlines, would clang
make use of it (i.e. output cleanups rather than turning them into catch-alls)?

Ciao, Duncan.