// Copyright 2017 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_VISITORS_H_ #define V8_VISITORS_H_ #include "src/allocation.h" namespace v8 { namespace internal { class Object; #define ROOT_ID_LIST(V) \ V(kStringTable, "string_table", "(Internalized strings)") \ V(kExternalStringsTable, "external_strings_table", "(External strings)") \ V(kStrongRootList, "strong_root_list", "(Strong roots)") \ V(kSmiRootList, "smi_root_list", "(Smi roots)") \ V(kBootstrapper, "bootstrapper", "(Bootstrapper)") \ V(kTop, "top", "(Isolate)") \ V(kRelocatable, "relocatable", "(Relocatable)") \ V(kDebug, "debug", "(Debugger)") \ V(kCompilationCache, "compilationcache", "(Compilation cache)") \ V(kHandleScope, "handlescope", "(Handle scope)") \ V(kDispatchTable, "dispatchtable", "(Dispatch table)") \ V(kBuiltins, "builtins", "(Builtins)") \ V(kGlobalHandles, "globalhandles", "(Global handles)") \ V(kEternalHandles, "eternalhandles", "(Eternal handles)") \ V(kThreadManager, "threadmanager", "(Thread manager)") \ V(kStrongRoots, "strong roots", "(Strong roots)") \ V(kExtensions, "Extensions", "(Extensions)") class VisitorSynchronization : public AllStatic { public: #define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item, enum SyncTag { ROOT_ID_LIST(DECLARE_ENUM) kNumberOfSyncTags }; #undef DECLARE_ENUM static const char* const kTags[kNumberOfSyncTags]; static const char* const kTagNames[kNumberOfSyncTags]; }; enum class Root { #define DECLARE_ENUM(enum_item, ignore1, ignore2) enum_item, ROOT_ID_LIST(DECLARE_ENUM) #undef DECLARE_ENUM // TODO(ulan): Merge with the ROOT_ID_LIST. kCodeFlusher, kPartialSnapshotCache, kWeakCollections, kWrapperTracing, kUnknown }; // Abstract base class for visiting, and optionally modifying, the // pointers contained in roots. Used in GC and serialization/deserialization. class RootVisitor BASE_EMBEDDED { public: virtual ~RootVisitor() {} // Visits a contiguous arrays of pointers in the half-open range // [start, end). Any or all of the values may be modified on return. virtual void VisitRootPointers(Root root, Object** start, Object** end) = 0; // Handy shorthand for visiting a single pointer. virtual void VisitRootPointer(Root root, Object** p) { VisitRootPointers(root, p, p + 1); } // Intended for serialization/deserialization checking: insert, or // check for the presence of, a tag at this position in the stream. // Also used for marking up GC roots in heap snapshots. // TODO(ulan): Remove this. virtual void Synchronize(VisitorSynchronization::SyncTag tag) {} }; } // namespace internal } // namespace v8 #endif // V8_VISITORS_H_