[clang-tidy] Add recursion protection in ExceptionSpecAnalyzer (llvm#66810)

Normally endless recursion should not happen in ExceptionSpecAnalyzer,
but if AST would be malformed (missing include), this could cause crash.

I run into this issue when due to missing include constructor argument
were parsed as FieldDecl.
As checking for recursion cost nothing, why not to do this in check just
in case.

Fixes llvm#111436

Author: PiotrZSL

clang-tools-extra/clang-tidy/utils/ExceptionSpecAnalyzer.cpp

@@ -14,13 +14,14 @@ namespace clang::tidy::utils {
 
 ExceptionSpecAnalyzer::State
 ExceptionSpecAnalyzer::analyze(const FunctionDecl *FuncDecl) {
-  // Check if the function has already been analyzed and reuse that result.
-  const auto CacheEntry = FunctionCache.find(FuncDecl);
-  if (CacheEntry == FunctionCache.end()) {
+  // Check if function exist in cache or add temporary value to cache to protect
+  // against endless recursion.
+  const auto [CacheEntry, NotFound] =
+      FunctionCache.try_emplace(FuncDecl, State::NotThrowing);
+  if (NotFound) {
     ExceptionSpecAnalyzer::State State = analyzeImpl(FuncDecl);
-
-    // Cache the result of the analysis.
-    FunctionCache.try_emplace(FuncDecl, State);
+    // Update result with calculated value
+    FunctionCache[FuncDecl] = State;
     return State;
   }
 

clang-tools-extra/test/clang-tidy/checkers/performance/noexcept-move-constructor.cpp

@@ -1,4 +1,6 @@
 // RUN: %check_clang_tidy %s performance-noexcept-move-constructor %t -- -- -fexceptions
+// RUN: %check_clang_tidy -std=c++17 -check-suffixes=,ERR %s performance-noexcept-move-constructor %t \
+// RUN:                   -- --fix-errors -- -fexceptions -DENABLE_ERROR
 
 namespace std
 {
@@ -397,3 +399,18 @@ namespace gh68101
       Container(Container&&) noexcept(std::is_nothrow_move_constructible<T>::value);
   };
 } // namespace gh68101
+
+namespace gh111436
+{
+
+template <typename value_type> class set {
+  set(set &&) = default;
+
+#ifdef ENABLE_ERROR
+  set(initializer_list<value_type> __l) {};
+  // CHECK-MESSAGES-ERR: :[[@LINE-1]]:7: error: member 'initializer_list' cannot have template arguments [clang-diagnostic-error]
+  // CHECK-MESSAGES-ERR: :[[@LINE-2]]:36: error: expected ')' [clang-diagnostic-error]
+#endif
+};
+
+} // namespace gh111436