PR17615: A delegating constructor initializer is a full-expression. Don't

forget to clean up temporaries at the end of it.

llvm-svn: 194213

Author: zygoloid

clang/lib/AST/ExprConstant.cpp

@@ -3623,8 +3623,11 @@ static bool HandleConstructorCall(SourceLocation CallLoc, const LValue &This,
   // If it's a delegating constructor, just delegate.
   if (Definition->isDelegatingConstructor()) {
     CXXConstructorDecl::init_const_iterator I = Definition->init_begin();
-    if (!EvaluateInPlace(Result, Info, This, (*I)->getInit()))
-      return false;
+    {
+      FullExpressionRAII InitScope(Info);
+      if (!EvaluateInPlace(Result, Info, This, (*I)->getInit()))
+        return false;
+    }
     return EvaluateStmt(Result, Info, Definition->getBody()) != ESR_Failed;
   }
 

clang/test/SemaCXX/constant-expression-cxx1y.cpp

@@ -887,3 +887,14 @@ namespace Bitfields {
   }
   static_assert(test(), "");
 }
+
+namespace PR17615 {
+  struct A {
+    int &&r;
+    constexpr A(int &&r) : r(static_cast<int &&>(r)) {}
+    constexpr A() : A(0) {
+      (void)+r; // expected-note {{outside its lifetime}}
+    }
+  };
+  constexpr int k = A().r; // expected-error {{constant expression}} expected-note {{in call to}}
+}