[llvm-commits] [patch] Change how we handle mandatory unwind tables

[Rafael Avila de Espindola]

On 11-05-24 03:14 PM, Duncan Sands wrote:
> Hi Rafael,
>
>> So, what I don't understand now is why do I need a three state then? If keeping
>> nounwind as is, I only need one bit more to tell me if the user or the ABI
>> requires me to produce an unwind table entry.
>
> the user might have explicitly asked for unwind-tables (using -funwind-tables),
> or explicitly asked for no unwind-tables (using -fno-unwind-tables), or
> explicitly asked for neither.  That makes three states :)

Ah. The reason I think we don't need the third one is that the user not 
stating his preference just falls back to the ABI. That is, on x86, the 
following two commands are equivalent

* clang -c foo.c
* clang -c -fno-asynchronous-unwind-table- foo.c

While on x86_64 the following two are:

* clang -c foo.c
* clang -c -fasynchronous-unwind-tables foo.c

> Ciao, Duncan.

Cheers,
Rafael