[clang] [Sema] Avoid repeated hash lookups (NFC) (PR #127301)

[Kazu Hirata via cfe-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/127301

None

>From 8dc601728da95660090898624f083c64a72ae6aa Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Fri, 14 Feb 2025 02:45:21 -0800
Subject: [PATCH] [Sema] Avoid repeated hash lookups (NFC)

---
 clang/lib/Sema/SemaDecl.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 98c245cdea78f..362df485a025c 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -16014,7 +16014,8 @@ static void diagnoseImplicitlyRetainedSelf(Sema &S) {
   llvm::DenseMap<const BlockDecl *, bool> EscapeInfo;
 
   auto IsOrNestedInEscapingBlock = [&](const BlockDecl *BD) {
-    if (auto It = EscapeInfo.find(BD); It != EscapeInfo.end())
+    auto [It, Inserted] = EscapeInfo.try_emplace(BD);
+    if (!Inserted)
       return It->second;
 
     bool R = false;
@@ -16027,7 +16028,7 @@ static void diagnoseImplicitlyRetainedSelf(Sema &S) {
       CurBD = CurBD->getParent()->getInnermostBlockDecl();
     } while (CurBD);
 
-    return EscapeInfo[BD] = R;
+    return It->second = R;
   };
 
   // If the location where 'self' is implicitly retained is inside a escaping