Clear the LV cache when merging the availability attribute.

The availability implies default visibility, so it can change the computed
visibility.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171840 91177308-0d34-0410-b5e6-96231b3b80d8

Author: espindola

lib/Sema/SemaDecl.cpp

@@ -1790,12 +1790,16 @@ DeclHasAttr(const Decl *D, const Attr *A) {
 
 bool Sema::mergeDeclAttribute(Decl *D, InheritableAttr *Attr) {
   InheritableAttr *NewAttr = NULL;
-  if (AvailabilityAttr *AA = dyn_cast<AvailabilityAttr>(Attr))
+  if (AvailabilityAttr *AA = dyn_cast<AvailabilityAttr>(Attr)) {
     NewAttr = mergeAvailabilityAttr(D, AA->getRange(), AA->getPlatform(),
                                     AA->getIntroduced(), AA->getDeprecated(),
                                     AA->getObsoleted(), AA->getUnavailable(),
                                     AA->getMessage());
-  else if (VisibilityAttr *VA = dyn_cast<VisibilityAttr>(Attr)) {
+    if (NewAttr) {
+      NamedDecl *ND = cast<NamedDecl>(D);
+      ND->ClearLVCache();
+    }
+  } else if (VisibilityAttr *VA = dyn_cast<VisibilityAttr>(Attr)) {
     NewAttr = mergeVisibilityAttr(D, VA->getRange(), VA->getVisibility());
     if (NewAttr) {
       NamedDecl *ND = cast<NamedDecl>(D);

test/Sema/attr-availability.c

@@ -43,3 +43,6 @@ void f7(int) __attribute__((availability(ios,deprecated=4.0))); // expected-warn
 #if !__has_feature(attribute_availability_with_message)
 # error "Missing __has_feature"
 #endif
+
+extern int x __attribute__((availability(macosx,introduced=10.5)));
+extern int x;