From a9e9ebcfb5268f2ebab8c46ea9e025e1c0caeddc Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Sat, 19 May 2012 23:35:23 +0000
Subject: [PATCH] Make delegating initializers use a similar codepath to base
 initializers in dependent contexts.  PR12890.

llvm-svn: 157136
---
 clang/lib/Sema/SemaDeclCXX.cpp                      | 10 ++++++++++
 clang/test/SemaTemplate/delegating-constructors.cpp | 18 ++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 9571a26..676063a 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -2234,6 +2234,16 @@ Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
   if (DelegationInit.isInvalid())
     return true;
 
+  // If we are in a dependent context, template instantiation will
+  // perform this type-checking again. Just save the arguments that we
+  // received in a ParenListExpr.
+  // FIXME: This isn't quite ideal, since our ASTs don't capture all
+  // of the information that we have about the base
+  // initializer. However, deconstructing the ASTs is a dicey process,
+  // and this approach is far more likely to get the corner cases right.
+  if (CurContext->isDependentContext())
+    DelegationInit = Owned(Init);
+
   return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(), 
                                           DelegationInit.takeAs<Expr>(),
                                           InitRange.getEnd());
diff --git a/clang/test/SemaTemplate/delegating-constructors.cpp b/clang/test/SemaTemplate/delegating-constructors.cpp
index e177b50..852b89d 100644
--- a/clang/test/SemaTemplate/delegating-constructors.cpp
+++ b/clang/test/SemaTemplate/delegating-constructors.cpp
@@ -29,3 +29,21 @@ namespace PR10457 {
     Foo f(1, 1);
   }
 }
+
+namespace PR12890 {
+  class Document
+  {
+  public:
+      Document() = default;
+
+      template <class T>
+      explicit
+      Document(T&& t) : Document()
+      {
+      }
+  };
+  void f()
+  {
+      Document d(1);
+  }
+}
-- 
2.7.4