[clang] [analyzer][NFC] Substitute operator() with lambda in StreamChecker (PR #69844)

[Ben Shi via cfe-commits]

https://github.com/benshi001 updated https://github.com/llvm/llvm-project/pull/69844

>From 615c6f8ecc4a97eeedc69c04b9a805ee56822c30 Mon Sep 17 00:00:00 2001
From: Ben Shi <bennshi at tencent.com>
Date: Sat, 21 Oct 2023 21:33:50 +0800
Subject: [PATCH] [analyzer][NFC] Substitute operator() with lambda in
 StreamChecker

---
 .../StaticAnalyzer/Checkers/StreamChecker.cpp | 21 ++++++-------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index bad86682c91e25f..ef209f64f0c372c 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -407,23 +407,14 @@ class StreamChecker : public Checker<check::PreCall, eval::Call,
 
   /// Generate a message for BugReporterVisitor if the stored symbol is
   /// marked as interesting by the actual bug report.
-  // FIXME: Use lambda instead.
-  struct NoteFn {
-    const BugType *BT_ResourceLeak;
-    SymbolRef StreamSym;
-    std::string Message;
-
-    std::string operator()(PathSensitiveBugReport &BR) const {
-      if (BR.isInteresting(StreamSym) && &BR.getBugType() == BT_ResourceLeak)
-        return Message;
-
-      return "";
-    }
-  };
-
   const NoteTag *constructNoteTag(CheckerContext &C, SymbolRef StreamSym,
                                   const std::string &Message) const {
-    return C.getNoteTag(NoteFn{&BT_ResourceLeak, StreamSym, Message});
+    return C.getNoteTag([this, StreamSym,
+                         Message](PathSensitiveBugReport &BR) -> std::string {
+      if (BR.isInteresting(StreamSym) && &BR.getBugType() == &BT_ResourceLeak)
+        return Message;
+      return "";
+    });
   }
 
   const NoteTag *constructSetEofNoteTag(CheckerContext &C,