Issue warning for trivial cases of nonnull attributes

(on functions with no pointer arguments) but only when
the attribute has not been coming from a macro 
instantiation in a header file. Fixes first part
of radar 6857843.

llvm-svn: 114860

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index dce1bf84fcc..09feb50bd30 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -375,8 +375,13 @@ static void HandleNonNullAttr(Decl *d, const AttributeList &Attr, Sema &S) {
 
     // No pointer arguments?  The attribute in this case is
     // trivially satisfied.
-    if (NonNullArgs.empty())
+    if (NonNullArgs.empty()) {
+      // Warn the trivial case only if attribute is not coming from a
+      // macro instantiation.
+      if (Attr.getLoc().isFileID())
+        S.Diag(Attr.getLoc(), diag::warn_attribute_nonnull_no_pointers);
       return;
+    }
   }
 
   unsigned* start = &NonNullArgs[0];