[Clang] Add C++11 spelling support for guarded_by attribute

clang/include/clang/Basic/Attr.td

@@ -4129,7 +4129,7 @@ def NoThreadSafetyAnalysis : InheritableAttr {
 }
 
 def GuardedBy : InheritableAttr {
-  let Spellings = [GNU<"guarded_by">];
+  let Spellings = [Clang<"guarded_by", 0>];
   let Args = [ExprArgument<"Arg">];
   let LateParsed = LateAttrParseExperimentalExt;
   let TemplateDependent = 1;

clang/lib/Analysis/ThreadSafetyCommon.cpp

@@ -394,6 +394,13 @@ til::SExpr *SExprBuilder::translateDeclRefExpr(const DeclRefExpr *DRE,
   if (const auto *VarD = dyn_cast<VarDecl>(VD))
     return translateVariable(VarD, Ctx);
 
+  if (const auto *FD = dyn_cast<FieldDecl>(VD)) {
+    if (Ctx && Ctx->SelfArg) {
+      til::SExpr *E = new (Arena) til::SApply(SelfVar);
+      return new (Arena) til::Project(E, FD);
+    }
+  }
+
   // For non-local variables, treat it as a reference to a named object.
   return new (Arena) til::LiteralPtr(VD);
 }

clang/test/SemaCXX/gh158116.cpp

@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wthread-safety -std=c++11 %s
+
+class __attribute__((lockable)) Mutex {
+public:
+  void lock() __attribute__((exclusive_lock_function));
+  void unlock() __attribute__((unlock_function));
+};
+
+class Foo {
+  Mutex mu;
+  int y __attribute__((guarded_by(mu)));
+  int z [[clang::guarded_by(mu)]];
+
+  void func1() {
+    y = 0;  // expected-warning{{writing variable 'y' requires holding}}
+    z = 1;  // expected-warning{{writing variable 'z' requires holding}}
+  }
+
+  void func2() {
+    mu.lock();
+    y = 2;
+    z = 3;
+    mu.unlock();
+  }
+};

clang/test/SemaCXX/warn-thread-safety-analysis.cpp

@@ -3590,14 +3590,10 @@ void requireDecl(RelockableScope &scope) {
 struct foo
 {
   Mutex mu;
-  // expected-note@+1{{see attribute on parameter here}}
   void require(RelockableScope &scope EXCLUSIVE_LOCKS_REQUIRED(mu));
   void callRequire(){
     RelockableScope scope(&mu);
-    // TODO: False positive due to incorrect parsing of parameter attribute arguments.
     require(scope);
-    // expected-warning@-1{{calling function 'require' requires holding mutex 'mu' exclusively}}
-    // expected-warning@-2{{mutex managed by 'scope' is 'mu' instead of 'mu'}}
   }
 };