From b52fde4185cd724f51aae4018b0f8278732379c7 Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Mon, 21 Mar 2011 18:38:03 +0000
Subject: [PATCH] Provide a means for CrashRecovery clients to determine if
 code is currently running while crash recovery cleanups are being processed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128008 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/CrashRecoveryContext.h | 4 ++++
 lib/Support/CrashRecoveryContext.cpp        | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/include/llvm/Support/CrashRecoveryContext.h b/include/llvm/Support/CrashRecoveryContext.h
index 6e975fe3a1c..28b31f3a782 100644
--- a/include/llvm/Support/CrashRecoveryContext.h
+++ b/include/llvm/Support/CrashRecoveryContext.h
@@ -63,6 +63,10 @@ public:
   /// thread which is in a protected context.
   static CrashRecoveryContext *GetCurrent();
 
+  /// \brief Return true if the current thread is recovering from a
+  /// crash.
+  static bool isRecoveringFromCrash();
+
   /// \brief Execute the provide callback function (with the given arguments) in
   /// a protected context.
   ///
diff --git a/lib/Support/CrashRecoveryContext.cpp b/lib/Support/CrashRecoveryContext.cpp
index e558662611f..899c3890d78 100644
--- a/lib/Support/CrashRecoveryContext.cpp
+++ b/lib/Support/CrashRecoveryContext.cpp
@@ -57,11 +57,15 @@ public:
 static sys::Mutex gCrashRecoveryContexMutex;
 static bool gCrashRecoveryEnabled = false;
 
+static sys::ThreadLocal<const CrashRecoveryContextCleanup> 
+       tlIsRecoveringFromCrash;
+
 CrashRecoveryContextCleanup::~CrashRecoveryContextCleanup() {}
 
 CrashRecoveryContext::~CrashRecoveryContext() {
   // Reclaim registered resources.
   CrashRecoveryContextCleanup *i = head;
+  tlIsRecoveringFromCrash.set(head);
   while (i) {
     CrashRecoveryContextCleanup *tmp = i;
     i = tmp->next;
@@ -69,11 +73,16 @@ CrashRecoveryContext::~CrashRecoveryContext() {
     tmp->recoverResources();
     delete tmp;
   }
+  tlIsRecoveringFromCrash.erase();
   
   CrashRecoveryContextImpl *CRCI = (CrashRecoveryContextImpl *) Impl;
   delete CRCI;
 }
 
+bool CrashRecoveryContext::isRecoveringFromCrash() {
+  return tlIsRecoveringFromCrash.get() != 0;
+}
+
 CrashRecoveryContext *CrashRecoveryContext::GetCurrent() {
   if (!gCrashRecoveryEnabled)
     return 0;
-- 
2.34.1