From: David Blaikie <dblaikie@gmail.com>
Date: Mon, 28 Apr 2014 22:41:39 +0000 (+0000)
Subject: DIE: Document some learnings about why the world isn't perfect.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d200f074f518bc5a5192a887add1dc0b7816cb8a;p=oota-llvm.git

DIE: Document some learnings about why the world isn't perfect.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207458 91177308-0d34-0410-b5e6-96231b3b80d8
---

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;