njames93 updated this revision to Diff 309512.
njames93 added a comment.
Made ManagedStatic code transparent to users for RefCounted objects.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D92480/new/
https://reviews.llvm.org/D92480
Files:
clang/lib/ASTMatchers/ASTMatchersInternal.cpp
llvm/include/llvm/ADT/IntrusiveRefCntPtr.h
llvm/include/llvm/Support/ManagedStatic.h
Index: llvm/include/llvm/Support/ManagedStatic.h
===================================================================
--- llvm/include/llvm/Support/ManagedStatic.h
+++ llvm/include/llvm/Support/ManagedStatic.h
@@ -15,21 +15,79 @@
#include <atomic>
#include <cstddef>
+#include <type_traits>
namespace llvm {
+namespace detail {
+// Helper struct to detect classes that has Retain and Release member functions
+// that are const with no params.
+template <typename T> struct HasRetainRelease {
+private:
+ template <typename U>
+ static constexpr decltype(std::declval<U const>().Retain(),
+ std::declval<U const>().Release(), bool())
+ test(int) {
+ return true;
+ }
+
+ template <typename U> static constexpr bool test(...) { return false; }
+
+public:
+ static constexpr bool Value = test<T>(int());
+};
+
+template <typename T>
+std::enable_if_t<!HasRetainRelease<T>::Value, void *> createObject() {
+ return new T();
+}
+
+template <typename T>
+std::enable_if_t<HasRetainRelease<T>::Value, void *> createObject() {
+ T *Ptr = new T();
+ Ptr->Retain();
+ return Ptr;
+}
+
+template <typename T>
+std::enable_if_t<!HasRetainRelease<T>::Value> deleteObject(T *Ptr) {
+ delete Ptr;
+}
+
+template <typename T>
+std::enable_if_t<HasRetainRelease<T>::Value> deleteObject(T *Ptr) {
+ Ptr->Release();
+}
+
+template <typename T, size_t N>
+std::enable_if_t<!HasRetainRelease<T>::Value> deleteObject(T *Ptr) {
+ delete[] Ptr;
+}
+
+template <typename T, size_t N>
+std::enable_if_t<HasRetainRelease<T>::Value> deleteObject(T *Ptr) {
+ for (auto I = Ptr, E = I + N; I != E; ++I)
+ I->Release();
+}
+} // namespace detail
+
/// object_creator - Helper method for ManagedStatic.
-template <class C> struct object_creator {
- static void *call() { return new C(); }
+
+template <typename T> struct object_creator {
+ static void *call() { return detail::createObject<T>(); }
};
/// object_deleter - Helper method for ManagedStatic.
-///
template <typename T> struct object_deleter {
- static void call(void *Ptr) { delete (T *)Ptr; }
+ static void call(void *Ptr) {
+ return detail::deleteObject(static_cast<T *>(Ptr));
+ }
};
+
template <typename T, size_t N> struct object_deleter<T[N]> {
- static void call(void *Ptr) { delete[](T *)Ptr; }
+ static void call(void *Ptr) {
+ return detail::deleteObject<T, N>(static_cast<T *>(Ptr));
+ }
};
// ManagedStatic must be initialized to zero, and it must *not* have a dynamic
Index: llvm/include/llvm/ADT/IntrusiveRefCntPtr.h
===================================================================
--- llvm/include/llvm/ADT/IntrusiveRefCntPtr.h
+++ llvm/include/llvm/ADT/IntrusiveRefCntPtr.h
@@ -70,11 +70,23 @@
template <class Derived> class RefCountedBase {
mutable unsigned RefCount = 0;
-public:
+protected:
RefCountedBase() = default;
RefCountedBase(const RefCountedBase &) {}
RefCountedBase &operator=(const RefCountedBase &) = delete;
+#ifndef NDEBUG
+ ~RefCountedBase() {
+ assert(RefCount == 0 &&
+ "Destruction occured when there are still references to this.");
+ }
+#else
+ // Default the destructor in release builds, A trivial destructor may enable
+ // better codegen.
+ ~RefCountedBase() = default;
+#endif
+
+public:
void Retain() const { ++RefCount; }
void Release() const {
@@ -94,6 +106,17 @@
ThreadSafeRefCountedBase &
operator=(const ThreadSafeRefCountedBase &) = delete;
+#ifndef NDEBUG
+ ~ThreadSafeRefCountedBase() {
+ assert(RefCount == 0 &&
+ "Destruction occured when there are still references to this.");
+ }
+#else
+ // Default the destructor in release builds, A trivial destructor may enable
+ // better codegen.
+ ~ThreadSafeRefCountedBase() = default;
+#endif
+
public:
void Retain() const { RefCount.fetch_add(1, std::memory_order_relaxed); }
Index: clang/lib/ASTMatchers/ASTMatchersInternal.cpp
===================================================================
--- clang/lib/ASTMatchers/ASTMatchersInternal.cpp
+++ clang/lib/ASTMatchers/ASTMatchersInternal.cpp
@@ -156,9 +156,7 @@
/// of cache hits.
class TrueMatcherImpl : public DynMatcherInterface {
public:
- TrueMatcherImpl() {
- Retain(); // Reference count will never become zero.
- }
+ TrueMatcherImpl() = default;
bool dynMatches(const DynTypedNode &, ASTMatchFinder *,
BoundNodesTreeBuilder *) const override {
@@ -191,6 +189,9 @@
IntrusiveRefCntPtr<DynMatcherInterface> InnerMatcher;
};
+// Use a custom deleter for the TrueMatcherInstance ManagedStatic. This prevents
+// an assert firing when the refcount is nonzero while running its destructor.
+
} // namespace
static llvm::ManagedStatic<TrueMatcherImpl> TrueMatcherInstance;
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