1 files changed, 23 insertions, 12 deletions
diff --git a/clang/test/SemaCXX/constant-expression-cxx11.cpp b/clang/test/SemaCXX/constant-expression-cxx11.cpp
index e64f2d5a335..68b82c7d96f 100644
--- a/clang/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/clang/test/SemaCXX/constant-expression-cxx11.cpp
@@ -604,20 +604,31 @@ static_assert(NATDCArray{}[1][1].n == 0, "");
 
 }
 
-// Tests for indexes into arrays of unknown bounds.
+// Per current CWG direction, we reject any cases where pointer arithmetic is
+// not statically known to be valid.
 namespace ArrayOfUnknownBound {
-  // This is a corner case of the language where it's not clear whether this
-  // should be an error: When we see the initializer for Z::a, the bounds of
-  // Z::b aren't known yet, but they will be known by the end of the translation
-  // unit, so the compiler can in theory check the indexing into Z::b.
-  // For the time being, as long as this is unclear, we want to make sure that
-  // this compiles.
-  struct Z {
-    static const void *const a[];
-    static const void *const b[];
+  extern int arr[];
+  constexpr int *a = arr;
+  constexpr int *b = &arr[0];
+  static_assert(a == b, "");
+  constexpr int *c = &arr[1]; // expected-error {{constant}} expected-note {{indexing of array without known bound}}
+  constexpr int *d = &a[1]; // expected-error {{constant}} expected-note {{indexing of array without known bound}}
+  constexpr int *e = a + 1; // expected-error {{constant}} expected-note {{indexing of array without known bound}}
+
+  struct X {
+    int a;
+    int b[]; // expected-warning {{C99}}
   };
-  constexpr const void *Z::a[] = {&b[0], &b[1]};
-  constexpr const void *Z::b[] = {&a[0], &a[1]};
+  extern X x;
+  constexpr int *xb = x.b; // expected-error {{constant}} expected-note {{not supported}}
+
+  struct Y { int a; };
+  extern Y yarr[];
+  constexpr Y *p = yarr;
+  constexpr int *q = &p->a;
+
+  extern const int carr[]; // expected-note {{here}}
+  constexpr int n = carr[0]; // expected-error {{constant}} expected-note {{non-constexpr variable}}
 }
 
 namespace DependentValues {