[WebKit Checkers] Allow "singleton" suffix to be camelCased. (llvm#108257)

We should allow singleton and fooSingleton as singleton function names.

Author: rniwa

clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp

@@ -231,11 +231,9 @@ bool isSingleton(const FunctionDecl *F) {
     if (!MethodDecl->isStatic())
       return false;
   }
-  const auto &Name = safeGetName(F);
-  std::string SingletonStr = "singleton";
-  auto index = Name.find(SingletonStr);
-  return index != std::string::npos &&
-         index == Name.size() - SingletonStr.size();
+  const auto &NameStr = safeGetName(F);
+  StringRef Name = NameStr; // FIXME: Make safeGetName return StringRef.
+  return Name == "singleton" || Name.ends_with("Singleton");
 }
 
 // We only care about statements so let's use the simple

clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg.cpp

@@ -343,6 +343,12 @@ class RefCounted {
     return s_RefCounted;
   }
 
+  static RefCounted& otherSingleton() {
+    static RefCounted s_RefCounted;
+    s_RefCounted.ref();
+    return s_RefCounted;
+  }
+
   Number nonTrivial1() { return Number(3) + Number(4); }
   Number nonTrivial2() { return Number { 0.3 }; }
   int nonTrivial3() { return v ? otherFunction() : 0; }
@@ -512,6 +518,8 @@ class UnrelatedClass {
 
     RefCounted::singleton().trivial18(); // no-warning
     RefCounted::singleton().someFunction(); // no-warning
+    RefCounted::otherSingleton().trivial18(); // no-warning
+    RefCounted::otherSingleton().someFunction(); // no-warning
 
     getFieldTrivial().recursiveTrivialFunction(7); // no-warning
     getFieldTrivial().recursiveComplexFunction(9);