Create ConstantExpr class

A ConstantExpr class represents a full expression that's in a context where a
constant expression is required. This class reflects the path the evaluator
took to reach the expression rather than the syntactic context in which the
expression occurs.

In the future, the class will be expanded to cache the result of the evaluated
expression so that it's not needlessly re-evaluated

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D53475

llvm-svn: 345692

1 files changed, 5 insertions, 2 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index d5bbbd2b57c..bf08d6bb657 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -143,8 +143,8 @@ namespace {
     // If we're doing a variable assignment from e.g. malloc(N), there will
     // probably be a cast of some kind. In exotic cases, we might also see a
     // top-level ExprWithCleanups. Ignore them either way.
-    if (const auto *EC = dyn_cast<ExprWithCleanups>(E))
-      E = EC->getSubExpr()->IgnoreParens();
+    if (const auto *FE = dyn_cast<FullExpr>(E))
+      E = FE->getSubExpr()->IgnoreParens();
 
     if (const auto *Cast = dyn_cast<CastExpr>(E))
       E = Cast->getSubExpr()->IgnoreParens();
@@ -11062,6 +11062,9 @@ static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
     return
       CheckICE(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(), Ctx);
 
+  case Expr::ConstantExprClass:
+    return CheckICE(cast<ConstantExpr>(E)->getSubExpr(), Ctx);
+
   case Expr::ParenExprClass:
     return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
   case Expr::GenericSelectionExprClass: