r347531 - A "constexpr" is evaluated in a constant context. Make sure this is reflected

[Bill Wendling via cfe-commits]

Author: void
Date: Sun Nov 25 18:10:53 2018
New Revision: 347531

URL: http://llvm.org/viewvc/llvm-project?rev=347531&view=rev
Log:
A "constexpr" is evaluated in a constant context. Make sure this is reflected
if a __builtin_constant_p() is a part of a constexpr.

Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp
    cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=347531&r1=347530&r2=347531&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Sun Nov 25 18:10:53 2018
@@ -10882,6 +10882,7 @@ bool Expr::EvaluateAsInitializer(APValue
                                       ? 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
 
   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;

Modified: cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp?rev=347531&r1=347530&r2=347531&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp (original)
+++ cfe/trunk/test/SemaCXX/constant-expression-cxx1y.cpp Sun Nov 25 18:10:53 2018
@@ -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");