1 files changed, 49 insertions, 0 deletions
diff --git a/deps/v8/src/heap/cppgc/stack.h b/deps/v8/src/heap/cppgc/stack.h
new file mode 100644
index 0000000000..599bf3a54a
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/stack.h
@@ -0,0 +1,49 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_STACK_H_
+#define V8_HEAP_CPPGC_STACK_H_
+
+#include "src/base/macros.h"
+
+// TODO(chromium:1056170): Implement all platforms.
+#if defined(V8_TARGET_ARCH_X64)
+#define CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN 1
+#endif
+
+namespace cppgc {
+namespace internal {
+
+class StackVisitor {
+ public:
+  virtual void VisitPointer(const void* address) = 0;
+};
+
+// Abstraction over the stack. Supports handling of:
+// - native stack;
+// - ASAN/MSAN;
+// - SafeStack: https://releases.llvm.org/10.0.0/tools/clang/docs/SafeStack.html
+class V8_EXPORT_PRIVATE Stack final {
+ public:
+  explicit Stack(const void* stack_start);
+
+  // Returns true if |slot| is part of the stack and false otherwise.
+  bool IsOnStack(void* slot) const;
+
+  // Word-aligned iteration of the stack. Slot values are passed on to
+  // |visitor|.
+#ifdef CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+  void IteratePointers(StackVisitor* visitor) const;
+#endif  // CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+
+ private:
+  void IteratePointersImpl(StackVisitor* visitor, intptr_t* stack_end) const;
+
+  const void* stack_start_;
+};
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_STACK_H_