[LLVMdev] tblgen internals

[Chris Lattner]

On Dec 12, 2010, at 8:12 PM, Garrison Venn wrote:

>> I believe I caught most of the syntax style issues with the attached patch. It only contains
>> these style changes.

Thanks! I applied your followup patch in r121837.

> Concerning the RecordKeeper reference in Record. Would you prefer to partially go
> back to a more limited constrained version of a global. Since we are not threaded anyway,
> we could turn the reference into a singleton for the duration of an initial parse and use session.
> The concept would be to instead make the reference a static pointer, make RecordKeeper
> a friend of Record, and add RecordKeeper::resetSession(void). resetSession would set
> the static pointer to itself. Asserts would also have to be added to the methods which needed
> a Record to have a non-NULL RecordKeeper pointer. Although we would in effect still be
> using a global, we would be allowing it to be controlled while simultaneously removing the
> sizeof(RecordKeeper*) number of bytes from Record instances. Offsets into a another say 
> SmallVector instance could also be attempted, but this seems messy to me. 

I prefer to make RecordKeeper not a global.  This leaves us with three options: 1) keep the ivar reference, 2) pass the reference into any method that (transitively) needs the recordkeeper. 3) do #2, but refactor code so that it doesn't have to be passed around as much.

I honestly don't know what is best, if you think the current solution is good enough, lets stay with it.  Tblgen isn't exactly a paragon of high performance or low memory use anyway :)

Thanks Garrison!

-Chris