Emit CK_NoOp casts in C mode, not just C++.

Previously, it had been using CK_BitCast even for casts that only
change const/restrict/volatile. Now it will use CK_Noop where
appropriate.

This is an alternate solution to r336746.

Differential Revision: https://reviews.llvm.org/D52918

llvm-svn: 343892

1 files changed, 1 insertions, 5 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 8a2cbdc1871..a2e71ea061e 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -5864,11 +5864,7 @@ bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
     // permitted in constant expressions in C++11. Bitcasts from cv void* are
     // also static_casts, but we disallow them as a resolution to DR1312.
     if (!E->getType()->isVoidPointerType()) {
-      // If we changed anything other than cvr-qualifiers, we can't use this
-      // value for constant folding. FIXME: Qualification conversions should
-      // always be CK_NoOp, but we get this wrong in C.
-      if (!Info.Ctx.hasCvrSimilarType(E->getType(), E->getSubExpr()->getType()))
-        Result.Designator.setInvalid();
+      Result.Designator.setInvalid();
       if (SubExpr->getType()->isVoidPointerType())
         CCEDiag(E, diag::note_constexpr_invalid_cast)
           << 3 << SubExpr->getType();