fix PR10395 - array decay can produce an interesting type when

decaying an array of incomplete type (which has type [0 x i8]*) to a
normal pointer (which has incompletetype*).

llvm-svn: 135565

2 files changed, 11 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index 37d424a2b35..f64e98ef684 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1075,7 +1075,10 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
       V = Builder.CreateStructGEP(V, 0, "arraydecay");
     }
 
-    return V;
+    // Make sure the array decay ends up being the right type.  This matters if
+    // the array type was of an incomplete type.
+    return CGF.Builder.CreateBitCast(V, 
+                              CGF.getTypes().ConvertTypeForMem(CE->getType()));
   }
   case CK_FunctionToPointerDecay:
     return EmitLValue(E).getAddress();
diff --git a/clang/test/CodeGenCXX/init-incomplete-type.cpp b/clang/test/CodeGenCXX/init-incomplete-type.cpp
index 1755dfb7beb..4f37eeb9754 100644
--- a/clang/test/CodeGenCXX/init-incomplete-type.cpp
+++ b/clang/test/CodeGenCXX/init-incomplete-type.cpp
@@ -28,4 +28,10 @@ namespace incomplete_type_refs {
     return &g[1];
   }
 
-}
\ No newline at end of file
+}
+
+namespace PR10395 {
+  struct T;
+  extern T x[];
+  T* f() { return x; }
+}