[llvm] r185993 - Un-break the buildbot by tweaking the indirection flag.

[David Blaikie]

On Wed, Jul 10, 2013 at 12:05 PM, Adrian Prantl <aprantl at apple.com> wrote:
>
>
> On Jul 10, 2013, at 12:01 PM, Eric Christopher <echristo at gmail.com> wrote:
>
>>> +        // Set the indirect flag if the type and the DIVariable's
>>> +        // indirect field are in disagreement: Indirectly-addressed
>>> +        // variables that are nonpointer types should be marked as
>>> +        // indirect, and VLAs should be marked as indirect eventhough
>>> +        // they are a pointer type.
>>> +        bool IsIndirect = DI->getAddress()->getType()->isPointerTy()
>>> +          ^ DIVar.isIndirect();
>>>
>>
>> This change bothers me. Why can't it be explicit what kind of location
>> we're expecting?
>
> The problem is the currently the semantic of the IsIndirect field in DIVariable doesn’t allow us to do that. Currently the flag indicates that "this variable is represented as a pointer”. If we change that to mean “is an indirect address”, then we could generate less ambiguous MDNodes in the frontend.

I'm not sure I understand the distinction - but perhaps it's just a
matter of a poor phrasing in the comment I wrote.

"IsIndirect" represents the case where a variable will be represented
by a pointer in IR but that pointer isn't the value of the variable -
it's a pointer to the value of the variable (as in ABIs that pass
non-trivial C++ object parameters as pointers).

Could you describe in more detail the distinction you're making? I'm
not sure I'm following.