[clang] p0388 conversion to incomplete array

This implements the new implicit conversion sequence to an incomplete
(unbounded) array type.  It is mostly Richard Smith's work, updated to
trunk, testcases added and a few bugs fixed found in such testing.

It is not a complete implementation of p0388.

Differential Revision: https://reviews.llvm.org/D102645

1 files changed, 13 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index ed485ed6f5d1..866da292819f 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -2154,10 +2154,22 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
   }
   case CK_AtomicToNonAtomic:
   case CK_NonAtomicToAtomic:
-  case CK_NoOp:
   case CK_UserDefinedConversion:
     return Visit(const_cast<Expr*>(E));
 
+  case CK_NoOp: {
+    llvm::Value *V = Visit(const_cast<Expr *>(E));
+    if (V) {
+      // CK_NoOp can model a pointer qualification conversion, which can remove
+      // an array bound and change the IR type.
+      // FIXME: Once pointee types are removed from IR, remove this.
+      llvm::Type *T = ConvertType(DestTy);
+      if (T != V->getType())
+        V = Builder.CreateBitCast(V, T);
+    }
+    return V;
+  }
+
   case CK_BaseToDerived: {
     const CXXRecordDecl *DerivedClassDecl = DestTy->getPointeeCXXRecordDecl();
     assert(DerivedClassDecl && "BaseToDerived arg isn't a C++ object pointer!");