Index: clang/include/clang/Basic/Attr.td
===================================================================
--- clang/include/clang/Basic/Attr.td
+++ clang/include/clang/Basic/Attr.td
@@ -3561,3 +3561,33 @@
   let SemaHandler = 0;
   let Documentation = [Undocumented];
 }
+
+def NoRefCntblBaseVirtualDtor : InheritableAttr {
+  let Spellings = [Clang<"NoRefCntblBaseVirtualDtor">];
+  let Subjects = SubjectList<[CXXRecord]>;
+  let Documentation = [Undocumented];
+}
+
+def NoUncountedLambdaCaptures : InheritableAttr {
+  let Spellings = [Clang<"NoUncountedLambdaCaptures">];
+  let Subjects = SubjectList<[Var]>;
+  let Documentation = [Undocumented];
+}
+
+def NoNoUncountedMember : InheritableAttr {
+  let Spellings = [Clang<"NoNoUncountedMember">];
+  let Subjects = SubjectList<[Field]>;
+  let Documentation = [Undocumented];
+}
+
+def NoUncountedLocalVars : InheritableAttr {
+  let Spellings = [Clang<"NoUncountedLocalVars">];
+  let Subjects = SubjectList<[Var]>;
+  let Documentation = [Undocumented];
+}
+
+def NoUncountedCallArgs : InheritableAttr {
+  let Spellings = [Clang<"NoUncountedCallArgs">];
+  let Subjects = SubjectList<[ParmVar]>;
+  let Documentation = [Undocumented];
+}
Index: clang/lib/Sema/SemaDeclAttr.cpp
===================================================================
--- clang/lib/Sema/SemaDeclAttr.cpp
+++ clang/lib/Sema/SemaDeclAttr.cpp
@@ -7963,6 +7963,26 @@
   case ParsedAttr::AT_UseHandle:
     handleHandleAttr<UseHandleAttr>(S, D, AL);
     break;
+
+  case ParsedAttr::AT_NoRefCntblBaseVirtualDtor:
+    handleSimpleAttribute<NoRefCntblBaseVirtualDtorAttr>(S, D, AL);
+    break;
+
+  case ParsedAttr::AT_NoUncountedLambdaCaptures:
+    handleSimpleAttribute<NoUncountedLambdaCapturesAttr>(S, D, AL);
+    break;
+
+  case ParsedAttr::AT_NoNoUncountedMember:
+    handleSimpleAttribute<NoNoUncountedMemberAttr>(S, D, AL);
+    break;
+
+  case ParsedAttr::AT_NoUncountedLocalVars:
+    handleSimpleAttribute<NoUncountedLocalVarsAttr>(S, D, AL);
+    break;
+
+  case ParsedAttr::AT_NoUncountedCallArgs:
+    handleSimpleAttribute<NoUncountedCallArgsAttr>(S, D, AL);
+    break;
   }
 }
 
Index: clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp
+++ clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp
@@ -74,6 +74,9 @@
       if (!MemberType)
         continue;
 
+      if (Member->hasAttr<NoNoUncountedMemberAttr>())
+        continue;
+
       if (auto *MemberCXXRD = MemberType->getPointeeCXXRecordDecl()) {
         // If we don't see the definition we just don't know.
         if (MemberCXXRD->hasDefinition()) {
Index: clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
+++ clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
@@ -122,6 +122,9 @@
         SrcMgr::C_User)
       return true;
 
+    if (RD->hasAttr<NoRefCntblBaseVirtualDtorAttr>())
+      return true;
+
     return false;
   }
 
Index: clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
+++ clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
@@ -81,6 +81,9 @@
         // if ((*P)->hasAttr<SafeRefCntblRawPtrAttr>())
         //  continue;
 
+        if ((*P)->hasAttr<NoUncountedCallArgsAttr>())
+          continue;
+
         const auto *ArgType = (*P)->getType().getTypePtrOrNull();
         if (!ArgType)
           continue; // FIXME? Should we bail?
Index: clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
+++ clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
@@ -58,6 +58,11 @@
     for (const LambdaCapture &C : L->captures()) {
       if (C.capturesVariable()) {
         VarDecl *CapturedVar = C.getCapturedVar();
+        if (!CapturedVar)
+          continue;
+        if (CapturedVar->hasAttr<NoUncountedLambdaCapturesAttr>())
+          continue;
+
         if (auto *CapturedVarType = CapturedVar->getType().getTypePtrOrNull()) {
           Optional<bool> IsUncountedPtr = isUncountedPtr(CapturedVarType);
           if (IsUncountedPtr && *IsUncountedPtr) {
Index: clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
+++ clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
@@ -222,6 +222,9 @@
     if (isDeclaredInForOrIf(V))
       return true;
 
+    if (V->hasAttr<NoUncountedLocalVarsAttr>())
+      return true;
+
     return false;
   }
 
Index: clang/test/Analysis/Checkers/WebKit/call-args.cpp
===================================================================
--- clang/test/Analysis/Checkers/WebKit/call-args.cpp
+++ clang/test/Analysis/Checkers/WebKit/call-args.cpp
@@ -342,3 +342,10 @@
     // expected-warning@-1{{Call argument for parameter 'bad' is uncounted and unsafe}}
   }
 }
+
+namespace suppression {
+  void consume_refcntbl_unsafe([[clang::NoUncountedCallArgs]] RefCountable*) {}
+  void foo() {
+    consume_refcntbl_unsafe(provide());
+  }
+}
Index: clang/test/Analysis/Checkers/WebKit/ref-cntbl-base-virtual-dtor.cpp
===================================================================
--- clang/test/Analysis/Checkers/WebKit/ref-cntbl-base-virtual-dtor.cpp
+++ clang/test/Analysis/Checkers/WebKit/ref-cntbl-base-virtual-dtor.cpp
@@ -13,7 +13,7 @@
   virtual ~DerivedWithVirtualDtor() {}
 };
 
-
+struct [[clang::NoRefCntblBaseVirtualDtor]] Derived2 : RefCntblBase { };
 
 template<class T>
 struct DerivedClassTmpl : T { };
Index: clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp
===================================================================
--- clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp
+++ clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp
@@ -42,3 +42,10 @@
   auto foo4 = [=]() {};
   RefCountable *ref_countable = nullptr;
 }
+
+void suppressed() {
+  RefCountable patatino;
+  RefCountable& ref_countable_ref [[clang::NoUncountedLambdaCaptures]] = patatino;
+
+  auto foo1 = [ref_countable_ref](){};
+}
\ No newline at end of file
Index: clang/test/Analysis/Checkers/WebKit/uncounted-local-vars.cpp
===================================================================
--- clang/test/Analysis/Checkers/WebKit/uncounted-local-vars.cpp
+++ clang/test/Analysis/Checkers/WebKit/uncounted-local-vars.cpp
@@ -97,3 +97,10 @@
   for (RefCountable *a : array) { }
 }
 } // namespace ignore_for_if
+
+namespace suppression {
+void foo_ref() {
+  RefCountable automatic;
+  RefCountable &bar [[clang::NoUncountedLocalVars]] = automatic;
+}
+}
Index: clang/test/Analysis/Checkers/WebKit/uncounted-members.cpp
===================================================================
--- clang/test/Analysis/Checkers/WebKit/uncounted-members.cpp
+++ clang/test/Analysis/Checkers/WebKit/uncounted-members.cpp
@@ -41,3 +41,9 @@
 
   void forceTmplToInstantiate(RefPtr<RefCountable>) {}
 }
+
+namespace suppression {
+  struct Foo {
+    RefCountable* a [[clang::NoNoUncountedMember]] = nullptr;
+  };
+}