[AST] Bump Type::NumOfBuiltinTypeBits. NFCI.

[jayfoad]

BuiltinType::LastKind is currently 507 which is close to the current
limit of 511.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Jay Foad (jayfoad)

Changes

BuiltinType::LastKind is currently 507 which is close to the current
limit of 511.

---

Full diff: https://github.com/llvm/llvm-project/pull/113559.diff

1 Files Affected:

• (modified) clang/include/clang/AST/Type.h (+1-1)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index ba3161c366f4d9..2598a794fe8796 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -1930,7 +1930,7 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
     unsigned : NumTypeBits;
 
     /// The kind (BuiltinType::Kind) of builtin type this is.
-    static constexpr unsigned NumOfBuiltinTypeBits = 9;
+    static constexpr unsigned NumOfBuiltinTypeBits = 10;
     unsigned Kind : NumOfBuiltinTypeBits;
   };
 

[jayfoad]

This is mostly so that we don't need to carry this change downstream, while we have downstream patches that add a few builtin types. It seems inevitable that it will need to be changed upstream pretty soon anyway.

[AaronBallman]

The community doesn't add new builtin types particularly often, so having four leftover bits isn't actually that close to the limit for us. Is there a problem with keeping this change downstream until we get to the limit in community?

[jayfoad]

The community doesn't add new builtin types particularly often, so having four leftover bits isn't actually that close to the limit for us.

I guess "close" is subjective.

Is there a problem with keeping this change downstream until we get to the limit in community?

No, I was just trying to separate out some changes that seemed upstreamable.

[AaronBallman]

The community doesn't add new builtin types particularly often, so having four leftover bits isn't actually that close to the limit for us.

I guess "close" is subjective.

Is there a problem with keeping this change downstream until we get to the limit in community?

No, I was just trying to separate out some changes that seemed upstreamable.

Ah! I appreciate the effort, but yeah, this one may cause more questions like "why are we using 10 bits when we only need 9?" while folks review code. Otherwise, it is harmless (it doesn't seem to increase the size of anything, so it's not adding extra memory pressure anywhere).