[llvm] r217291 - [MCJIT] Fix an iterator invalidation bug in MCJIT::finalizeObject.

[Lang Hames]

Author: lhames
Date: Fri Sep  5 18:38:35 2014
New Revision: 217291

URL: http://llvm.org/viewvc/llvm-project?rev=217291&view=rev
Log:
[MCJIT] Fix an iterator invalidation bug in MCJIT::finalizeObject.

The finalizeObject method calls generateCodeForModule on each of the currently
'added' objects, but generateCodeForModule moves objects out of the 'added'
set as it's called. To avoid iterator invalidation issues, the added set is
copied out before any calls to generateCodeForModule.

This should fix http://llvm.org/PR20851 .

Modified:
    llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.cpp
    llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.h

Modified: llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.cpp?rev=217291&r1=217290&r2=217291&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.cpp (original)
+++ llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.cpp Fri Sep  5 18:38:35 2014
@@ -225,12 +225,14 @@ void MCJIT::finalizeLoadedModules() {
 void MCJIT::finalizeObject() {
   MutexGuard locked(lock);
 
-  for (ModulePtrSet::iterator I = OwnedModules.begin_added(),
-                              E = OwnedModules.end_added();
-       I != E; ++I) {
-    Module *M = *I;
+  // Generate code for module is going to move objects out of the 'added' list,
+  // so we need to copy that out before using it:
+  SmallVector<Module*, 16> ModsToAdd;
+  for (auto M : OwnedModules.added())
+    ModsToAdd.push_back(M);
+
+  for (auto M : ModsToAdd)
     generateCodeForModule(M);
-  }
 
   finalizeLoadedModules();
 }

Modified: llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.h?rev=217291&r1=217290&r2=217291&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.h (original)
+++ llvm/trunk/lib/ExecutionEngine/MCJIT/MCJIT.h Fri Sep  5 18:38:35 2014
@@ -118,6 +118,9 @@ class MCJIT : public ExecutionEngine {
 
     ModulePtrSet::iterator begin_added() { return AddedModules.begin(); }
     ModulePtrSet::iterator end_added() { return AddedModules.end(); }
+    iterator_range<ModulePtrSet::iterator> added() {
+      return iterator_range<ModulePtrSet::iterator>(begin_added(), end_added());
+    }
 
     ModulePtrSet::iterator begin_loaded() { return LoadedModules.begin(); }
     ModulePtrSet::iterator end_loaded() { return LoadedModules.end(); }