[PATCH] D152140: [Clang] Limit FunctionTypeExtraBitfields::NumExceptionType to 16 bits.

[Sander de Smalen via Phabricator via cfe-commits]

sdesmalen added inline comments.


================
Comment at: clang/include/clang/AST/Type.h:3956
     /// [implimits] 8 bits would be enough here.
-    unsigned NumExceptionType = 0;
+    unsigned NumExceptionType : 16;
+
----------------
erichkeane wrote:
> sdesmalen wrote:
> > erichkeane wrote:
> > > tbaeder wrote:
> > > > Isn't using a `uint16_t` preferred over a bitfield?
> > > Ah, thats a great point, yes, I think that is probably better here!  I like the assert on setting it (particularly because we're shrinking it!), but that idea makes this patch much smaller.
> > The reason for making this a bitfield rather than uint16_t is because D127762 extends the struct with another (bit)field:
> > 
> >     /// Any AArch64 SME ACLE type attributes that need to be propagated
> >     /// on declarations and function pointers.
> >     unsigned AArch64SMEAttributes : 6;
> > 
> > I thought having this all be bitfields made more sense, but I'm happy to change it to a uint16_t if that is preferred.
> > 
> > > that idea makes this patch much smaller
> > I suspect that the assert is still required to ensure that the value stored fits the value? Using `uint16_t` doesn't change that, or did I miss something? :)
> We don't need them all to be bitfields, they'll take up the same amount of space with out it, and save us a bit of oddity.
> 
> I like the assert still as well, but since this size is set in 1 place, an assert there would be fine as well.
Okay that makes sense, thanks.


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D152140/new/

https://reviews.llvm.org/D152140