3 files changed, 42 insertions, 0 deletions

diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 5802aaad96..d9e4df058d 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -3719,6 +3719,34 @@ void Sema::ProcessDeclAttributeList(Scope *S, Decl *D,
   }
 }
 
+/// checkUnusedDeclAttributes - Check a list of attributes to see if it
+/// contains any decl attributes that we should warn about.
+static void checkUnusedDeclAttributes(Sema &S, const AttributeList *A) {
+  for ( ; A; A = A->getNext()) {
+    // Only warn if the attribute is an unignored, non-type attribute.
+    if (A->isUsedAsTypeAttr()) continue;
+    if (A->getKind() == AttributeList::IgnoredAttribute) continue;
+
+    if (A->getKind() == AttributeList::UnknownAttribute) {
+      S.Diag(A->getLoc(), diag::warn_unknown_attribute_ignored)
+        << A->getName() << A->getRange();
+    } else {
+      S.Diag(A->getLoc(), diag::warn_attribute_not_on_decl)
+        << A->getName() << A->getRange();
+    }
+  }
+}
+
+/// checkUnusedDeclAttributes - Given a declarator which is not being
+/// used to build a declaration, complain about any decl attributes
+/// which might be lying around on it.
+void Sema::checkUnusedDeclAttributes(Declarator &D) {
+  ::checkUnusedDeclAttributes(*this, D.getDeclSpec().getAttributes().getList());
+  ::checkUnusedDeclAttributes(*this, D.getAttributes());
+  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i)
+    ::checkUnusedDeclAttributes(*this, D.getTypeObject(i).getAttrs());
+}
+
 /// DeclClonePragmaWeak - clone existing decl (maybe definition),
 /// #pragma weak needs a non-definition decl and source may not have one
 NamedDecl * Sema::DeclClonePragmaWeak(NamedDecl *ND, IdentifierInfo *II,
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 0fea54b77d..d0a3f6b5ec 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -4291,6 +4291,8 @@ Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc,
     CheckExtraCXXDefaultArguments(D);
   }
 
+  checkUnusedDeclAttributes(D);
+
   QualType castType = castTInfo->getType();
   Ty = CreateParsedType(castType, castTInfo);
 
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 25ec0b1477..9707804cf0 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -3064,6 +3064,9 @@ TypeResult Sema::ActOnTypeName(Scope *S, Declarator &D) {
   if (D.isInvalidType())
     return true;
 
+  // Make sure there are no unused decl attributes on the declarator.
+  checkUnusedDeclAttributes(D);
+
   if (getLangOptions().CPlusPlus) {
     // Check that there are no default arguments (C++ only).
     CheckExtraCXXDefaultArguments(D);
@@ -3758,30 +3761,37 @@ static void processTypeAttrs(TypeProcessingState &state, QualType &type,
 
     case AttributeList::AT_address_space:
       HandleAddressSpaceTypeAttribute(type, attr, state.getSema());
+      attr.setUsedAsTypeAttr();
       break;
     OBJC_POINTER_TYPE_ATTRS_CASELIST:
       if (!handleObjCPointerTypeAttr(state, attr, type))
         distributeObjCPointerTypeAttr(state, attr, type);
+      attr.setUsedAsTypeAttr();
       break;
     case AttributeList::AT_vector_size:
       HandleVectorSizeAttr(type, attr, state.getSema());
+      attr.setUsedAsTypeAttr();
       break;
     case AttributeList::AT_ext_vector_type:
       if (state.getDeclarator().getDeclSpec().getStorageClassSpec()
             != DeclSpec::SCS_typedef)
         HandleExtVectorTypeAttr(type, attr, state.getSema());
+      attr.setUsedAsTypeAttr();
       break;
     case AttributeList::AT_neon_vector_type:
       HandleNeonVectorTypeAttr(type, attr, state.getSema(),
                                VectorType::NeonVector, "neon_vector_type");
+      attr.setUsedAsTypeAttr();
       break;
     case AttributeList::AT_neon_polyvector_type:
       HandleNeonVectorTypeAttr(type, attr, state.getSema(),
                                VectorType::NeonPolyVector,
                                "neon_polyvector_type");
+      attr.setUsedAsTypeAttr();
       break;
     case AttributeList::AT_opencl_image_access:
       HandleOpenCLImageAccessAttribute(type, attr, state.getSema());
+      attr.setUsedAsTypeAttr();
       break;
 
     case AttributeList::AT_ns_returns_retained:
@@ -3790,6 +3800,8 @@ static void processTypeAttrs(TypeProcessingState &state, QualType &type,
       // fallthrough into the function attrs
 
     FUNCTION_TYPE_ATTRS_CASELIST:
+      attr.setUsedAsTypeAttr();
+
       // Never process function type attributes as part of the
       // declaration-specifiers.
       if (isDeclSpec)