[clang] [lldb] Serialize `#pragma redefine_extname` into precompiled headers. (PR #186755)

[Paul Kirth via cfe-commits]

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@@ -9687,6 +9709,28 @@ void ASTReader::ReadWeakUndeclaredIdentifiers(
   WeakUndeclaredIdentifiers.clear();
 }
 
+void ASTReader::ReadExtnameUndeclaredIdentifiers(
+    SmallVectorImpl<std::pair<IdentifierInfo *, AsmLabelAttr *>> &ExtnameIDs) {
+  if (ExtnameUndeclaredIdentifiers.empty())
+    return;
+
+  for (unsigned I = 0, N = ExtnameUndeclaredIdentifiers.size(); I < N;
+       /*none*/) {
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ilovepi wrote:

nit: As a reader of this code, I think I'd prefer `I+3` as the loop variable update and then specific indexing in the body eg `ExtnameUndeclaredIdentifiers[I+2]`. That's rather a style thing though, and I'll admit I didn't check if this is a common pattern in this file. It does also make me wonder if these lists should just be actual tuples you iterate over if they're only ever consumed together (or even if you should have a different type that maps the common ID to the 3 items). I've not thought about this very much, and indeed I've seldom needed to deal with the AST Reader, but its what came to mind as I read the patch.


https://github.com/llvm/llvm-project/pull/186755