[clang] [clang-tools-extra] [llvm] [Support][JSON] Use `std::map` for object storage (PR #171230)

[Zixu Wang via llvm-commits]

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@@ -94,9 +94,9 @@ class Value;
 template <typename T> Value toJSON(const std::optional<T> &Opt);
 
 /// An Object is a JSON object, which maps strings to heterogenous JSON values.
-/// It simulates DenseMap<ObjectKey, Value>. ObjectKey is a maybe-owned string.
+/// ObjectKey is a maybe-owned string.
 class Object {
-  using Storage = DenseMap<ObjectKey, Value, llvm::DenseMapInfo<StringRef>>;
+  using Storage = std::map<ObjectKey, Value>;
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zixu-w wrote:

>From my understanding of the codebase, `ObjectKey` is always a string, but the generalization comes from the need to sometimes own the string. Before finding the `DenseMap` issue I also tried to optimize `ObjectKey` to make it just a `StringRef`, but sometimes the key can contain JSON escape sequence etc. etc. when it needs to be able to create a modified string as the key.

https://github.com/llvm/llvm-project/pull/171230