treat bool literals as constatnt expressions.

llvm-svn: 55255

clang/lib/AST/Expr.cpp

@@ -720,6 +720,13 @@ bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx,
     Result.setIsUnsigned(!getType()->isSignedIntegerType());
     break;
   }
+  case CXXBoolLiteralExprClass: {
+    const CXXBoolLiteralExpr *BL = cast<CXXBoolLiteralExpr>(this);
+    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
+    Result = BL->getValue();
+    Result.setIsUnsigned(!getType()->isSignedIntegerType());
+    break;
+  }
   case CXXZeroInitValueExprClass:
     Result.clear();
     break;

clang/test/SemaCXX/bool.cpp

+// RUN: clang -fsyntax-only -verify %s 
+
+// Bool literals can be enum values.
+enum {
+  ReadWrite = false,
+  ReadOnly = true
+};