[Sema] Avoid duplicate -Wunguarded-availability warnings in nested functions

rdar://31862310

llvm-svn: 303170

clang/lib/Sema/SemaDeclAttr.cpp

@@ -7230,6 +7230,13 @@ public:
         SemaRef.Context.getTargetInfo().getPlatformMinVersion());
   }
 
+  bool TraverseDecl(Decl *D) {
+    // Avoid visiting nested functions to prevent duplicate warnings.
+    if (!D || isa<FunctionDecl>(D))
+      return true;
+    return Base::TraverseDecl(D);
+  }
+
   bool TraverseStmt(Stmt *S) {
     if (!S)
       return true;
@@ -7243,6 +7250,8 @@ public:
 
   bool TraverseIfStmt(IfStmt *If);
 
+  bool TraverseLambdaExpr(LambdaExpr *E) { return true; }
+
   bool VisitObjCMessageExpr(ObjCMessageExpr *Msg) {
     if (ObjCMethodDecl *D = Msg->getMethodDecl())
       DiagnoseDeclAvailability(

clang/test/SemaObjC/unguarded-availability.m

@@ -8,7 +8,7 @@
 int func_10_11() AVAILABLE_10_11; // expected-note 4 {{'func_10_11' has been explicitly marked partial here}}
 
 #ifdef OBJCPP
-// expected-note@+2 2 {{marked partial here}}
+// expected-note@+2 6 {{marked partial here}}
 #endif
 int func_10_12() AVAILABLE_10_12; // expected-note 6 {{'func_10_12' has been explicitly marked partial here}}
 
@@ -188,4 +188,19 @@ auto topLevelLambda = [] () {
     func_10_12();
 };
 
+void functionInFunction() {
+  func_10_12(); // expected-warning{{'func_10_12' is only available on macOS 10.12 or newer}} expected-note{{@available}}
+  struct DontWarnTwice {
+    void f() {
+      func_10_12(); // expected-warning{{'func_10_12' is only available on macOS 10.12 or newer}} expected-note{{@available}}
+    }
+  };
+  void([] () {
+    func_10_12(); // expected-warning{{'func_10_12' is only available on macOS 10.12 or newer}} expected-note{{@available}}
+  });
+  (void)(^ {
+    func_10_12(); // expected-warning{{'func_10_12' is only available on macOS 10.12 or newer}} expected-note{{@available}}
+  });
+}
+
 #endif