From f9b06eb99eda8c1c0f3cced9d341c51af0b1aed1 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Mon, 28 Apr 2014 22:41:39 +0000
Subject: [PATCH] DIE: Document some learnings about why the world isn't
 perfect.

llvm-svn: 207458
---
 lib/CodeGen/AsmPrinter/DIE.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/CodeGen/AsmPrinter/DIE.h b/lib/CodeGen/AsmPrinter/DIE.h
index 1a1c080c32c..ef05f170781 100644
--- a/lib/CodeGen/AsmPrinter/DIE.h
+++ b/lib/CodeGen/AsmPrinter/DIE.h
@@ -124,6 +124,12 @@ protected:
 
   /// Children DIEs.
   ///
+  // This can't be a vector<DIE> because pointer validity is requirent for the
+  // Parent pointer and DIEEntry.
+  // It can't be a list<DIE> because some clients need pointer validity before
+  // the object has been added to any child list
+  // (eg: DwarfUnit::constructVariableDIE). These aren't insurmountable, but may
+  // be more convoluted than beneficial.
   std::vector<std::unique_ptr<DIE>> Children;
 
   DIE *Parent;