diff --git a/lib/Support/LeakDetector.cpp b/lib/Support/LeakDetector.cpp
new file mode 100644
index 00000000000..0d7b4bedf3d
--- /dev/null
+++ b/lib/Support/LeakDetector.cpp
@@ -0,0 +1,66 @@
+//===-- LeakDetector.cpp - Implement LeakDetector interface ---------------===//
+//
+// This file implements the LeakDetector class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Support/LeakDetector.h"
+#include "llvm/Value.h"
+#include <set>
+#include <iostream>
+
+// Lazily allocate set so that release build doesn't have to do anything.
+static std::set<const void*> *Objects = 0;
+static std::set<const Value*> *LLVMObjects = 0;
+
+void LeakDetector::addGarbageObjectImpl(void *Object) {
+  if (Objects == 0)
+    Objects = new std::set<const void*>();
+  assert(Objects->count(Object) == 0 && "Object already in set!");
+  Objects->insert(Object);
+}
+
+void LeakDetector::removeGarbageObjectImpl(void *Object) {
+  if (Objects)
+    Objects->erase(Object);
+}
+
+void LeakDetector::addGarbageObjectImpl(const Value *Object) {
+  if (LLVMObjects == 0)
+    LLVMObjects = new std::set<const Value*>();
+  assert(LLVMObjects->count(Object) == 0 && "Object already in set!");
+  LLVMObjects->insert(Object);
+}
+
+void LeakDetector::removeGarbageObjectImpl(const Value *Object) {
+  if (LLVMObjects)
+    LLVMObjects->erase(Object);
+}
+
+void LeakDetector::checkForGarbageImpl(const std::string &Message) {
+  if ((Objects && !Objects->empty()) || (LLVMObjects && !LLVMObjects->empty())){
+    std::cerr << "Leaked objects found: " << Message << "\n";
+
+    if (Objects && !Objects->empty()) {
+      std::cerr << "  Non-Value objects leaked:";
+      for (std::set<const void*>::iterator I = Objects->begin(),
+             E = Objects->end(); I != E; ++I)
+        std::cerr << " " << *I;
+    }
+
+    if (LLVMObjects && !LLVMObjects->empty()) {
+      std::cerr << "  LLVM Value subclasses leaked:";
+      for (std::set<const Value*>::iterator I = LLVMObjects->begin(),
+             E = LLVMObjects->end(); I != E; ++I)
+        std::cerr << **I << "\n";
+    }
+
+    std::cerr << "This is probably because you removed an LLVM value "
+              << "(Instruction, BasicBlock, \netc), but didn't delete it.  "
+              << "Please check your code for memory leaks.\n";
+
+    // Clear out results so we don't get duplicate warnings on next call...
+    delete Objects; delete LLVMObjects;
+    Objects = 0; LLVMObjects = 0;
+  }
+}
diff --git a/lib/VMCore/LeakDetector.cpp b/lib/VMCore/LeakDetector.cpp
new file mode 100644
index 00000000000..0d7b4bedf3d
--- /dev/null
+++ b/lib/VMCore/LeakDetector.cpp
@@ -0,0 +1,66 @@
+//===-- LeakDetector.cpp - Implement LeakDetector interface ---------------===//
+//
+// This file implements the LeakDetector class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Support/LeakDetector.h"
+#include "llvm/Value.h"
+#include <set>
+#include <iostream>
+
+// Lazily allocate set so that release build doesn't have to do anything.
+static std::set<const void*> *Objects = 0;
+static std::set<const Value*> *LLVMObjects = 0;
+
+void LeakDetector::addGarbageObjectImpl(void *Object) {
+  if (Objects == 0)
+    Objects = new std::set<const void*>();
+  assert(Objects->count(Object) == 0 && "Object already in set!");
+  Objects->insert(Object);
+}
+
+void LeakDetector::removeGarbageObjectImpl(void *Object) {
+  if (Objects)
+    Objects->erase(Object);
+}
+
+void LeakDetector::addGarbageObjectImpl(const Value *Object) {
+  if (LLVMObjects == 0)
+    LLVMObjects = new std::set<const Value*>();
+  assert(LLVMObjects->count(Object) == 0 && "Object already in set!");
+  LLVMObjects->insert(Object);
+}
+
+void LeakDetector::removeGarbageObjectImpl(const Value *Object) {
+  if (LLVMObjects)
+    LLVMObjects->erase(Object);
+}
+
+void LeakDetector::checkForGarbageImpl(const std::string &Message) {
+  if ((Objects && !Objects->empty()) || (LLVMObjects && !LLVMObjects->empty())){
+    std::cerr << "Leaked objects found: " << Message << "\n";
+
+    if (Objects && !Objects->empty()) {
+      std::cerr << "  Non-Value objects leaked:";
+      for (std::set<const void*>::iterator I = Objects->begin(),
+             E = Objects->end(); I != E; ++I)
+        std::cerr << " " << *I;
+    }
+
+    if (LLVMObjects && !LLVMObjects->empty()) {
+      std::cerr << "  LLVM Value subclasses leaked:";
+      for (std::set<const Value*>::iterator I = LLVMObjects->begin(),
+             E = LLVMObjects->end(); I != E; ++I)
+        std::cerr << **I << "\n";
+    }
+
+    std::cerr << "This is probably because you removed an LLVM value "
+              << "(Instruction, BasicBlock, \netc), but didn't delete it.  "
+              << "Please check your code for memory leaks.\n";
+
+    // Clear out results so we don't get duplicate warnings on next call...
+    delete Objects; delete LLVMObjects;
+    Objects = 0; LLVMObjects = 0;
+  }
+}
diff --git a/support/lib/Support/LeakDetector.cpp b/support/lib/Support/LeakDetector.cpp
new file mode 100644
index 00000000000..0d7b4bedf3d
--- /dev/null
+++ b/support/lib/Support/LeakDetector.cpp
@@ -0,0 +1,66 @@
+//===-- LeakDetector.cpp - Implement LeakDetector interface ---------------===//
+//
+// This file implements the LeakDetector class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Support/LeakDetector.h"
+#include "llvm/Value.h"
+#include <set>
+#include <iostream>
+
+// Lazily allocate set so that release build doesn't have to do anything.
+static std::set<const void*> *Objects = 0;
+static std::set<const Value*> *LLVMObjects = 0;
+
+void LeakDetector::addGarbageObjectImpl(void *Object) {
+  if (Objects == 0)
+    Objects = new std::set<const void*>();
+  assert(Objects->count(Object) == 0 && "Object already in set!");
+  Objects->insert(Object);
+}
+
+void LeakDetector::removeGarbageObjectImpl(void *Object) {
+  if (Objects)
+    Objects->erase(Object);
+}
+
+void LeakDetector::addGarbageObjectImpl(const Value *Object) {
+  if (LLVMObjects == 0)
+    LLVMObjects = new std::set<const Value*>();
+  assert(LLVMObjects->count(Object) == 0 && "Object already in set!");
+  LLVMObjects->insert(Object);
+}
+
+void LeakDetector::removeGarbageObjectImpl(const Value *Object) {
+  if (LLVMObjects)
+    LLVMObjects->erase(Object);
+}
+
+void LeakDetector::checkForGarbageImpl(const std::string &Message) {
+  if ((Objects && !Objects->empty()) || (LLVMObjects && !LLVMObjects->empty())){
+    std::cerr << "Leaked objects found: " << Message << "\n";
+
+    if (Objects && !Objects->empty()) {
+      std::cerr << "  Non-Value objects leaked:";
+      for (std::set<const void*>::iterator I = Objects->begin(),
+             E = Objects->end(); I != E; ++I)
+        std::cerr << " " << *I;
+    }
+
+    if (LLVMObjects && !LLVMObjects->empty()) {
+      std::cerr << "  LLVM Value subclasses leaked:";
+      for (std::set<const Value*>::iterator I = LLVMObjects->begin(),
+             E = LLVMObjects->end(); I != E; ++I)
+        std::cerr << **I << "\n";
+    }
+
+    std::cerr << "This is probably because you removed an LLVM value "
+              << "(Instruction, BasicBlock, \netc), but didn't delete it.  "
+              << "Please check your code for memory leaks.\n";
+
+    // Clear out results so we don't get duplicate warnings on next call...
+    delete Objects; delete LLVMObjects;
+    Objects = 0; LLVMObjects = 0;
+  }
+}