[llvm] r244337 - Add a comment.

[Nico Weber via llvm-commits]

Author: nico
Date: Fri Aug  7 12:32:06 2015
New Revision: 244337

URL: http://llvm.org/viewvc/llvm-project?rev=244337&view=rev
Log:
Add a comment.

Modified:
    llvm/trunk/lib/Support/CrashRecoveryContext.cpp

Modified: llvm/trunk/lib/Support/CrashRecoveryContext.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/CrashRecoveryContext.cpp?rev=244337&r1=244336&r2=244337&view=diff
==============================================================================
--- llvm/trunk/lib/Support/CrashRecoveryContext.cpp (original)
+++ llvm/trunk/lib/Support/CrashRecoveryContext.cpp Fri Aug  7 12:32:06 2015
@@ -24,6 +24,10 @@ static ManagedStatic<
     sys::ThreadLocal<const CrashRecoveryContextImpl> > CurrentContext;
 
 struct CrashRecoveryContextImpl {
+  // When threads are disabled, this links up all active
+  // CrashRecoveryContextImpls.  When threads are enabled there's one thread
+  // per CrashRecoveryContext and CurrentContext is a thread-local, so only one
+  // CrashRecoveryContextImpl is active per thread and this is always null.
   const CrashRecoveryContextImpl *Next;
 
   CrashRecoveryContext *CRC;