Don't warn about static const integral data members with in-line constant

initializers just because they don't have a proper out-of-line definition.
Such code is technically ill-formed but is too common and too unlikely to be
a problem to be seriously worth worrying about.

llvm-svn: 126137

2 files changed, 26 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 84baa7d9852..e7d167ed387 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -9336,9 +9336,12 @@ void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) {
       }
     }
 
-    // Keep track of used but undefined variables.
+    // Keep track of used but undefined variables.  We make a hole in
+    // the warning for static const data members with in-line
+    // initializers.
     if (Var->hasDefinition() == VarDecl::DeclarationOnly
-        && Var->getLinkage() != ExternalLinkage) {
+        && Var->getLinkage() != ExternalLinkage
+        && !(Var->isStaticDataMember() && Var->hasInit())) {
       SourceLocation &old = UndefinedInternals[Var->getCanonicalDecl()];
       if (old.isInvalid()) old = Loc;
     }
diff --git a/clang/test/SemaCXX/undefined-internal.cpp b/clang/test/SemaCXX/undefined-internal.cpp
index bb87ce0f126..a7e92499657 100644
--- a/clang/test/SemaCXX/undefined-internal.cpp
+++ b/clang/test/SemaCXX/undefined-internal.cpp
@@ -84,3 +84,24 @@ namespace test5 {
     B<A>::foo(); // expected-note {{used here}}
   }
 }
+
+namespace test6 {
+  template <class T> struct A {
+    static const int zero = 0;
+    static const int one = 1;
+    static const int two = 2;
+
+    int value;
+
+    A() : value(zero) {
+      value = one;
+    }
+  };
+
+  namespace { struct Internal; }
+
+  void test() {
+    A<Internal> a;
+    a.value = A<Internal>::two;
+  }
+}