From 3734251539d2192aafa938c530fa8eb45e48ecef Mon Sep 17 00:00:00 2001
From: Daniel Schemmel <daniel@schemmel.net>
Date: Thu, 29 Jun 2023 01:08:14 +0000
Subject: Have CoWPtr::get and CoWPtr::getOwned return pointers instead of
 references

---
 include/klee/KDAlloc/suballocators/cow_ptr.h       | 37 +++++++---------------
 include/klee/KDAlloc/suballocators/sized_regions.h | 21 ++++++------
 2 files changed, 21 insertions(+), 37 deletions(-)

diff --git a/include/klee/KDAlloc/suballocators/cow_ptr.h b/include/klee/KDAlloc/suballocators/cow_ptr.h
index 20e12701..ce5957df 100644
--- a/include/klee/KDAlloc/suballocators/cow_ptr.h
+++ b/include/klee/KDAlloc/suballocators/cow_ptr.h
@@ -87,41 +87,26 @@ public:
   /// Accesses an existing object.
   /// Must not be called when `*this` is in an empty state.
   T const &operator*() const noexcept {
-    assert(ptr && "the `CoWPtr` must not be empty");
-    return get();
+    assert(!isEmpty() && "the `CoWPtr` must not be empty");
+    return *get();
   }
 
   /// Accesses an existing object.
   /// Must not be called when `*this` is in an empty state.
   T const *operator->() const noexcept {
-    assert(ptr && "the `CoWPtr` must not be empty");
-    return &get();
-  }
-
-  /// Accesses an existing object.
-  /// Must not be called when `*this` is in an empty state.
-  T const &get() const noexcept {
-    assert(ptr && "the `CoWPtr` must not be empty");
-    return ptr->data;
+    assert(!isEmpty() && "the `CoWPtr` must not be empty");
+    return get();
   }
 
-  /// Accesses an existing, owned object.
-  /// Must not be called when `*this` does not hold CoW ownership.
-  T &getOwned() noexcept {
-    assert(isOwned() && "the `CoWPtr` must be owned");
-    return ptr->data;
-  }
+  /// Gets a pointer to the managed object.
+  /// Returns `nullptr` if no object is currently managed.
+  T const *get() const noexcept { return ptr ? &ptr->data : nullptr; }
 
-  /// Accesses an existing, owned object.
+  /// Gets a pointer to an existing, owned object.
   /// Must not be called when `*this` does not hold CoW ownership.
-  ///
-  /// Note: This function is included for completeness' sake. Instead of calling
-  /// `getOwned` on a constant, one should probably just call `get` as it
-  /// produces the same result without requiring the target object to hold
-  /// ownership of the data.
-  T const &getOwned() const noexcept {
+  T *getOwned() noexcept {
     assert(isOwned() && "the `CoWPtr` must be owned");
-    return ptr->data;
+    return &ptr->data;
   }
 
   /// Acquires CoW ownership of an existing object and returns a reference to
@@ -132,7 +117,7 @@ public:
     assert(ptr->referenceCount > 0);
     if (ptr->referenceCount > 1) {
       --ptr->referenceCount;
-      ptr = new Wrapper(*ptr);
+      ptr = new Wrapper{*ptr};
       ptr->referenceCount = 1;
     }
     assert(ptr->referenceCount == 1);
diff --git a/include/klee/KDAlloc/suballocators/sized_regions.h b/include/klee/KDAlloc/suballocators/sized_regions.h
index bb2a0b69..d8dafa86 100644
--- a/include/klee/KDAlloc/suballocators/sized_regions.h
+++ b/include/klee/KDAlloc/suballocators/sized_regions.h
@@ -162,7 +162,7 @@ public:
   [[nodiscard]] std::size_t getSize(char const *const address) const noexcept {
     assert(root && "Cannot get size from an empty treap");
 
-    Node const *currentNode = &*root;
+    Node const *currentNode = root.get();
     Node const *closestPredecessor = nullptr;
     Node const *closestSuccessor = nullptr;
     while (currentNode) {
@@ -170,12 +170,12 @@ public:
         assert(!closestSuccessor || currentNode->getBaseAddress() <
                                         closestSuccessor->getBaseAddress());
         closestSuccessor = currentNode;
-        currentNode = &*currentNode->lhs;
+        currentNode = currentNode->lhs.get();
       } else {
         assert(!closestPredecessor || currentNode->getBaseAddress() >
                                           closestPredecessor->getBaseAddress());
         closestPredecessor = currentNode;
-        currentNode = &*currentNode->rhs;
+        currentNode = currentNode->rhs.get();
       }
     }
 
@@ -195,7 +195,7 @@ public:
                                       std::size_t const size) const noexcept {
     assert(root && "Cannot compute location info for an empty treap");
 
-    Node const *currentNode = &*root;
+    Node const *currentNode = root.get();
     Node const *closestPredecessor = nullptr;
     for (;;) {
       if (currentNode->getBaseAddress() <= address) {
@@ -213,7 +213,7 @@ public:
                     closestPredecessor->getBaseAddress() +
                         closestPredecessor->getSize()};
           }
-          currentNode = &*currentNode->rhs;
+          currentNode = currentNode->rhs.get();
         }
       } else {
         assert(closestPredecessor &&
@@ -229,7 +229,7 @@ public:
                   closestPredecessor->getBaseAddress() +
                       closestPredecessor->getSize()};
         }
-        currentNode = &*currentNode->lhs;
+        currentNode = currentNode->lhs.get();
       }
     }
   }
@@ -307,7 +307,7 @@ private:
       target = &targetNode.lhs;
     }
 
-    update.getOwned().rhs = std::move(rhs);
+    update.getOwned()->rhs = std::move(rhs);
     *target = std::move(update);
   }
 
@@ -324,7 +324,7 @@ private:
       target = &targetNode.rhs;
     }
 
-    update.getOwned().lhs = std::move(lhs);
+    update.getOwned()->lhs = std::move(lhs);
     *target = std::move(update);
   }
 
@@ -423,9 +423,8 @@ public:
     CoWPtr<Node> *closestSuccessor = nullptr;
     for (;;) {
       if (address < (*currentNode)->getBaseAddress()) {
-        assert(!closestSuccessor ||
-               (*currentNode)->getBaseAddress() <
-                   (*closestSuccessor)->getBaseAddress());
+        assert(!closestSuccessor || (*currentNode)->getBaseAddress() <
+                                        (*closestSuccessor)->getBaseAddress());
         closestSuccessor = currentNode;
         if ((*currentNode)->lhs) {
           currentNode = &currentNode->acquire().lhs;
-- 
cgit 1.4.1