Allow a declaration of an array to complete a prior, incomplete
declaration of that array in C++.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@81309 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 6f04f7b..a72ca1d 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -980,6 +980,13 @@
   if (getLangOptions().CPlusPlus) {
     if (Context.hasSameType(New->getType(), Old->getType()))
       MergedT = New->getType();
+    // C++ [basic.types]p7:
+    //   [...] The declared type of an array object might be an array of 
+    //   unknown size and therefore be incomplete at one point in a 
+    //   translation unit and complete later on; [...]
+    else if (Old->getType()->isIncompleteArrayType() && 
+             New->getType()->isArrayType())
+      MergedT = New->getType();
   } else {
     MergedT = Context.mergeTypes(New->getType(), Old->getType());
   }