Fix memory leaks of ``Array`` objects detected by ASan.

Some of these leaks were introduced by the factory constructor for Array
objects (f049ff3bc04daead8c3bb9f06e89e71e2054c82a) but a few others have
been around for far longer.

This leak was fixed by introducing a ``ArrayCache`` object which has two
purposes

* Retains ownership of all created ``Array`` objects and destroys them when
  the ``ArrayCache`` destructor is called.
* Mimic the caching behaviour for symbolic arrays that was introduced
  by f049ff3bc04daead8c3bb9f06e89e71e2054c82a where arrays with the same
  name and size get "uniqued".

The Executor now maintains a ``arrayCache`` member that it uses and
passes by pointer to objects that need to construct ``Array`` objects (i.e.
``ObjectState``). This way when the Executor is destroyed all the
``Array`` objects get freed which seems like the right time to do this.

For Kleaver the ``ParserImpl`` has a ``TheArrayCache`` member that is
used for building ``Array`` objects. This means that the Parser must
live as long as the built expressions will be used otherwise we will
have a use after free. I'm not sure this is the right design choice.
It might be better to transfer ownership of the ``Array`` objects to
the root ``Decl`` returned by the parser.

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/Core/Executor.h b/lib/Core/Executor.h
index 523b3648..919d2124 100644
--- a/lib/Core/Executor.h
+++ b/lib/Core/Executor.h
@@ -20,6 +20,7 @@
 #include "klee/Internal/Module/Cell.h"
 #include "klee/Internal/Module/KInstruction.h"
 #include "klee/Internal/Module/KModule.h"
+#include "klee/util/ArrayCache.h"
 
 #include "llvm/ADT/Twine.h"
 
@@ -177,7 +178,10 @@ private:
 
   /// The maximum time to allow for a single core solver query.
   /// (e.g. for a single STP query)
-  double coreSolverTimeout; 
+  double coreSolverTimeout;
+
+  /// Assumes ownership of the created array objects
+  ArrayCache arrayCache;
 
   llvm::Function* getTargetFunction(llvm::Value *calledVal,
                                     ExecutionState &state);