diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -14207,6 +14207,9 @@
   if (isa<CXXMethodDecl>(FD))
     return false;
 
+  if (!FD->isExternallyVisible())
+    return false;
+
   // Don't warn about 'main'.
   if (isa<TranslationUnitDecl>(FD->getDeclContext()->getRedeclContext()))
     if (IdentifierInfo *II = FD->getIdentifier())
diff --git a/clang/test/SemaCXX/anonymous-struct.cpp b/clang/test/SemaCXX/anonymous-struct.cpp
--- a/clang/test/SemaCXX/anonymous-struct.cpp
+++ b/clang/test/SemaCXX/anonymous-struct.cpp
@@ -183,3 +183,9 @@
     void memcpy(); // expected-note {{due to this member}}
   } A; // expected-note {{given name 'A' for linkage purposes by this typedef}}
 }
+namespace inline_defined_static_member {
+typedef struct { // expected-warning {{anonymous non-C-compatible type}}
+  static void f() { // expected-note {{due to this member}}
+  }
+} A; // expected-note {{given name 'A' for linkage purposes by this typedef}}
+}
diff --git a/clang/test/SemaCXX/warn-missing-prototypes.cpp b/clang/test/SemaCXX/warn-missing-prototypes.cpp
--- a/clang/test/SemaCXX/warn-missing-prototypes.cpp
+++ b/clang/test/SemaCXX/warn-missing-prototypes.cpp
@@ -44,3 +44,16 @@
 extern void k() {} // expected-warning {{no previous prototype for function 'k'}}
 // expected-note@-1{{declare 'static' if the function is not intended to be used outside of this translation unit}}
 // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-2]]:{{.*}}-[[@LINE-2]]:{{.*}}}:"{{.*}}"
+
+namespace {
+struct anon { };
+}
+
+// No warning because this has internal linkage despite not being declared
+// explicitly 'static', owing to the internal linkage parameter.
+void l(anon) {
+}
+
+void *operator new(decltype(sizeof(3)) size, const anon &) throw() {
+  return nullptr;
+}