[clang] [NFC] [Serializer] Pack information in serializer (PR #69287)

[Vassil Vassilev via cfe-commits]

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@@ -2005,14 +2039,7 @@ void ASTWriter::WriteDeclAbbrevs() {
   // Decl
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
-  Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
-  Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
-  Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
-  Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
-  Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
-  Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
-  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
-  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));  // ModuleOwnershipKind
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // Decl Bits
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vgvassilev wrote:

These sections became a little harder to read. Perhaps we could keep the comments and this way the reader could probably do the math why this is 11 bits for example.

https://github.com/llvm/llvm-project/pull/69287