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

[Ben Shi via cfe-commits]

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

None

>From 0e8edd8448b0bacfaf35f415a5760d5d1a3aabb7 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 | 22 ++++++-------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index bad86682c91e25f..76df39cb37bd985 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -407,23 +407,15 @@ 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() == &(this->BT_ResourceLeak))
+            return Message;
+          return "";
+        });
   }
 
   const NoteTag *constructSetEofNoteTag(CheckerContext &C,