Another attempt at fixing PR2975.

Types can have references to eachother, so we can't just call destroy on them.

llvm-svn: 68523

examples/HowToUseJIT/HowToUseJIT.cpp

@@ -42,6 +42,7 @@
 #include "llvm/ExecutionEngine/JIT.h"
 #include "llvm/ExecutionEngine/Interpreter.h"
 #include "llvm/ExecutionEngine/GenericValue.h"
+#include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
@@ -109,5 +110,8 @@ int main() {
 
   // Import result of execution:
   outs() << "Result: " << gv.IntVal << "\n";
+  EE->freeMachineCodeForFunction(FooF);
+  delete EE;
+  llvm_shutdown();
   return 0;
 }

include/llvm/AbstractTypeUser.h

@@ -137,6 +137,7 @@ public:
 ///
 class PATypeHolder {
   mutable const Type *Ty;
+  void destroy();
 public:
   PATypeHolder(const Type *ty) : Ty(ty) {
     addRef();
@@ -145,7 +146,7 @@ public:
     addRef();
   }
 
-  ~PATypeHolder() { dropRef(); }
+  ~PATypeHolder() { if (Ty) dropRef(); }
 
   operator Type *() const { return get(); }
   Type *get() const;
@@ -173,6 +174,7 @@ public:
 private:
   void addRef();
   void dropRef();
+  friend class TypeMapBase;
 };
 
 // simplify_type - Allow clients to treat uses just like values when using

lib/VMCore/Type.cpp

@@ -388,6 +388,10 @@ OpaqueType::OpaqueType() : DerivedType(OpaqueTyID) {
 #endif
 }
 
+void PATypeHolder::destroy() {
+  Ty = 0;
+}
+
 // dropAllTypeUses - When this (abstract) type is resolved to be equal to
 // another (more concrete) type, we must eliminate all references to other
 // types, to avoid some circular reference problems.
@@ -666,6 +670,27 @@ protected:
   std::multimap<unsigned, PATypeHolder> TypesByHash;
 
 public:
+  ~TypeMapBase()
+  {
+    //PATypeHolder won't destroy non-abstract types.
+    //We can't destroy them by simply iterating,  because
+    //they may contain references to each-other
+
+    for (std::multimap<unsigned, PATypeHolder>::iterator I
+         = TypesByHash.begin(), E = TypesByHash.end(); I != E; ++I) {
+      Type *Ty = const_cast<Type*>(I->second.Ty);
+      I->second.destroy();
+      // We can't invoke destroy or delete, because the type may
+      // contain references to already freed types.
+      // So we have to destruct the object the ugly way.
+      if (Ty) {
+        Ty->AbstractTypeUsers.clear();
+        static_cast<const Type*>(Ty)->Type::~Type();
+        operator delete(Ty);
+      }
+    }
+  }
+
   void RemoveFromTypesByHash(unsigned Hash, const Type *Ty) {
     std::multimap<unsigned, PATypeHolder>::iterator I =
       TypesByHash.lower_bound(Hash);