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

llvm-svn: 304027

diff --git a/llvm/lib/Support/DynamicLibrary.cpp b/llvm/lib/Support/DynamicLibrary.cpp
index 1541a57..9398789 100644 (file)
--- a/llvm/lib/Support/DynamicLibrary.cpp
+++ b/llvm/lib/Support/DynamicLibrary.cpp
@@ -127,10 +127,15 @@ void DynamicLibrary::AddSymbol(StringRef SymbolName, void *SymbolValue) {
 
 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);
 }