[llvm] r304027 - Fix the ManagedStatic list ordering when using DynamicLibrary::addPermanentLibrary.

[Frederich Munch via llvm-commits]

Author: marsupial
Date: Fri May 26 14:43:23 2017
New Revision: 304027

URL: http://llvm.org/viewvc/llvm-project?rev=304027&view=rev
Log:
Fix the ManagedStatic list ordering when using DynamicLibrary::addPermanentLibrary.

Summary:
r295737 included a fix for leaking libraries loaded via. DynamicLibrary::addPermanentLibrary.
This created a problem where static constructors in a library could insert llvm::ManagedStatic objects before DynamicLibrary would register it's own ManagedStatic, meaning a crash could occur at shutdown.

r301562 exasperated this problem by cleaning up the DynamicLibrary ManagedStatic during llvm_shutdown.

Reviewers: v.g.vassilev, lhames, efriedma

Reviewed By: efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33581

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

Modified: llvm/trunk/lib/Support/DynamicLibrary.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/DynamicLibrary.cpp?rev=304027&r1=304026&r2=304027&view=diff
==============================================================================
--- llvm/trunk/lib/Support/DynamicLibrary.cpp (original)
+++ llvm/trunk/lib/Support/DynamicLibrary.cpp Fri May 26 14:43:23 2017
@@ -127,10 +127,15 @@ void DynamicLibrary::AddSymbol(StringRef
 
 DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *FileName,
                                                    std::string *Err) {
-  SmartScopedLock<true> Lock(*SymbolsMutex);
+  // Force OpenedHandles to be added into the ManagedStatic list before any
+  // ManagedStatic can be added from static constructors in HandleSet::DLOpen.
+  HandleSet& HS = *OpenedHandles;
+
   void *Handle = HandleSet::DLOpen(FileName, Err);
-  if (Handle != &Invalid)
-    OpenedHandles->AddLibrary(Handle, /*IsProcess*/ FileName == nullptr);
+  if (Handle != &Invalid) {
+    SmartScopedLock<true> Lock(*SymbolsMutex);
+    HS.AddLibrary(Handle, /*IsProcess*/ FileName == nullptr);
+  }
 
   return DynamicLibrary(Handle);
 }