From: Bill Wendling <isanbard@gmail.com>
Date: Mon, 26 Nov 2018 02:10:53 +0000 (+0000)
Subject: A "constexpr" is evaluated in a constant context. Make sure this is reflected
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ae4b8efe92f4f30b36da73166ac89a7dc50ba917;p=clang

A "constexpr" is evaluated in a constant context. Make sure this is reflected
if a __builtin_constant_p() is a part of a constexpr.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@347531 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 29508368d7..5eb2f2e7b8 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -10882,6 +10882,7 @@ bool Expr::EvaluateAsInitializer(APValue &Value, const ASTContext &Ctx,
                                       ? EvalInfo::EM_ConstantExpression
                                       : EvalInfo::EM_ConstantFold);
   InitInfo.setEvaluatingDecl(VD, Value);
+  InitInfo.InConstantContext = true;
 
   LValue LVal;
   LVal.set(VD);
@@ -11544,6 +11545,7 @@ bool Expr::isPotentialConstantExpr(const FunctionDecl *FD,
 
   EvalInfo Info(FD->getASTContext(), Status,
                 EvalInfo::EM_PotentialConstantExpression);
+  Info.InConstantContext = true;
 
   const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
   const CXXRecordDecl *RD = MD ? MD->getParent()->getCanonicalDecl() : nullptr;
diff --git a/test/SemaCXX/constant-expression-cxx1y.cpp b/test/SemaCXX/constant-expression-cxx1y.cpp
index eb555737d1..3214a2c086 100644
--- a/test/SemaCXX/constant-expression-cxx1y.cpp
+++ b/test/SemaCXX/constant-expression-cxx1y.cpp
@@ -1122,3 +1122,11 @@ constexpr E e2 = E{0};
 static_assert(e2.x != e2.y, "");
 
 } // namespace IndirectFields
+
+constexpr bool __constant_string_p(const char *__s) {
+  while (__builtin_constant_p(*__s) && *__s)
+    __s++;
+  return __builtin_constant_p(*__s);
+}
+
+constexpr bool n = __constant_string_p("a");