Walk the decls looking for the last one that has an attribute. We do have to walk
them, otherwise we cannot produce an error for both

struct HIDDEN test4; // canonical
struct test4;
struct DEFAULT test4;

and

struct test5; // canonical
struct HIDDEN test5;
struct DEFAULT test5;

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156016 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 13bf0aa..6b3f4f9 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -1757,13 +1757,16 @@
     return;
   }
 
-  Decl *PrevDecl;
-  if (isa<FunctionDecl>(D))
-    PrevDecl = D->getMostRecentDecl()->getPreviousDecl();
-  else
-    PrevDecl = D->getCanonicalDecl();
+  // Find the last Decl that has an attribute.
+  VisibilityAttr *PrevAttr;
+  assert(D->redecls_begin() == D);
+  for (Decl::redecl_iterator I = D->redecls_begin(), E = D->redecls_end();
+       I != E; ++I) {
+    PrevAttr = I->getAttr<VisibilityAttr>() ;
+    if (PrevAttr)
+      break;
+  }
 
-  VisibilityAttr *PrevAttr = PrevDecl ? PrevDecl->getAttr<VisibilityAttr>() : 0;
   if (PrevAttr) {
     VisibilityAttr::VisibilityType PrevVisibility = PrevAttr->getVisibility();
     if (PrevVisibility != type) {
diff --git a/test/Sema/attr-visibility.c b/test/Sema/attr-visibility.c
index 499111f..4996dca 100644
--- a/test/Sema/attr-visibility.c
+++ b/test/Sema/attr-visibility.c
@@ -10,3 +10,7 @@
 struct __attribute__((visibility("hidden"))) test4; // expected-note {{previous attribute is here}}
 struct test4;
 struct __attribute__((visibility("default"))) test4; // expected-error {{visibility does not match previous declaration}}
+
+struct test5;
+struct __attribute__((visibility("hidden"))) test5; // expected-note {{previous attribute is here}}
+struct __attribute__((visibility("default"))) test5; // expected-error {{visibility does not match previous declaration}}