Re: [PATCH v2 1/2] pkl: codegen: make struct_{constructor,deintegrator} exception-safe

[Jose E. Marchesi]

> Hi Jose.
>
> On Mon, Sep 26, 2022 at 01:22:18PM +0200, Jose E. Marchesi wrote:
>> 
>> > @@ -2174,9 +2178,15 @@
>> >          .let @itype = PKL_AST_TYPE_S_ITYPE (@type_struct)
>> >          .let @uint64_type = pkl_ast_make_integral_type (PKL_PASS_AST, 64, 
>> > 0)
>> >          .e zero_extend_64 @itype
>> > -        regvar $ival
>> > +        ;; If constraint violation exception happens during the
>> > +        ;; construction of deintegrated struct, this is the right
>> > +        ;; place to restore the stack.
>> > +        push PVM_E_CONSTRAINT
>> > +        pushe .constraint_failed
>> 
>> I agree the dup below is necessary in case the caller to
>> struct_deintegrator catches an exception and needs the stack restored
>> without the argument trashed.
>> 
>> But why is this intermediate `pushe' needed at all?  Just let the
>> exception fly thru.
>> 
>
> Right.  I over-thinked it.
> Either there's no exception handler and it reaches to the user,
> or there's a pushe somewhere and it will restore the stack height
> to right position.
>
> With removing this, is this OK for master?

Yes.  Thanks.