[clang] [AST] Avoid repeated map lookups (NFC) (PR #122858)

[Kazu Hirata via cfe-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/122858

None

>From 227e7f718acbef18a4b5e93cc6ea8cc0b2249062 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Mon, 13 Jan 2025 21:08:39 -0800
Subject: [PATCH] [AST] Avoid repeated map lookups (NFC)

---
 clang/lib/AST/ExternalASTMerger.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/clang/lib/AST/ExternalASTMerger.cpp b/clang/lib/AST/ExternalASTMerger.cpp
index 8bad3b36244e15..7f7816e1b10eae 100644
--- a/clang/lib/AST/ExternalASTMerger.cpp
+++ b/clang/lib/AST/ExternalASTMerger.cpp
@@ -276,8 +276,8 @@ bool ExternalASTMerger::HasImporterForOrigin(ASTContext &OriginContext) {
 template <typename CallbackType>
 void ExternalASTMerger::ForEachMatchingDC(const DeclContext *DC,
                                           CallbackType Callback) {
-  if (Origins.count(DC)) {
-    ExternalASTMerger::DCOrigin Origin = Origins[DC];
+  if (auto It = Origins.find(DC); It != Origins.end()) {
+    ExternalASTMerger::DCOrigin Origin = It->second;
     LazyASTImporter &Importer = LazyImporterForOrigin(*this, *Origin.AST);
     Callback(Importer, Importer.GetReverse(), Origin.DC);
   } else {