Move utils/pointer-with-payload.h -> base/pointer-with-payload.h

The utility type is independent of V8 and useful for cppgc as well.
Move to base/ to allow reusing.

Change-Id: I9de9b4a87bb113fb4c2232d90253afb0f38faa68
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3497336Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79346}

BUILD.bazel

@@ -590,6 +590,7 @@ filegroup(
         "src/base/platform/semaphore.h",
         "src/base/platform/time.cc",
         "src/base/platform/time.h",
+        "src/base/pointer-with-payload.h",
         "src/base/platform/wrappers.h",
         "src/base/region-allocator.cc",
         "src/base/region-allocator.h",
@@ -2050,7 +2051,6 @@ filegroup(
         "src/utils/memcopy.h",
         "src/utils/ostreams.cc",
         "src/utils/ostreams.h",
-        "src/utils/pointer-with-payload.h",
         "src/utils/scoped-list.h",
         "src/utils/utils-inl.h",
         "src/utils/utils.cc",

BUILD.gn

@@ -3438,7 +3438,6 @@ v8_header_set("v8_internal_headers") {
     "src/utils/locked-queue.h",
     "src/utils/memcopy.h",
     "src/utils/ostreams.h",
-    "src/utils/pointer-with-payload.h",
     "src/utils/scoped-list.h",
     "src/utils/utils-inl.h",
     "src/utils/utils.h",
@@ -5143,6 +5142,7 @@ v8_component("v8_libbase") {
     "src/base/platform/time.h",
     "src/base/platform/wrappers.h",
     "src/base/platform/yield-processor.h",
+    "src/base/pointer-with-payload.h",
     "src/base/region-allocator.cc",
     "src/base/region-allocator.h",
     "src/base/ring-buffer.h",

src/ast/ast.h

@@ -10,6 +10,7 @@
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/modules.h"
 #include "src/ast/variables.h"
+#include "src/base/pointer-with-payload.h"
 #include "src/base/threaded-list.h"
 #include "src/codegen/bailout-reason.h"
 #include "src/codegen/label.h"
@@ -1185,7 +1186,7 @@ class LiteralProperty : public ZoneObject {
   LiteralProperty(Expression* key, Expression* value, bool is_computed_name)
       : key_and_is_computed_name_(key, is_computed_name), value_(value) {}
 
-  PointerWithPayload<Expression, bool, 1> key_and_is_computed_name_;
+  base::PointerWithPayload<Expression, bool, 1> key_and_is_computed_name_;
   Expression* value_;
 };
 

src/ast/scopes.h

@@ -10,16 +10,28 @@
 #include "src/ast/ast.h"
 #include "src/base/compiler-specific.h"
 #include "src/base/hashmap.h"
+#include "src/base/pointer-with-payload.h"
 #include "src/base/threaded-list.h"
 #include "src/common/globals.h"
 #include "src/objects/function-kind.h"
 #include "src/objects/objects.h"
-#include "src/utils/pointer-with-payload.h"
 #include "src/utils/utils.h"
 #include "src/zone/zone-hashmap.h"
 #include "src/zone/zone.h"
 
 namespace v8 {
+
+namespace internal {
+class Scope;
+}  // namespace internal
+
+namespace base {
+template <>
+struct PointerWithPayloadTraits<v8::internal::Scope> {
+  static constexpr int kAvailableBits = 1;
+};
+}  // namespace base
+
 namespace internal {
 
 class AstNodeFactory;
@@ -64,13 +76,6 @@ class VariableMap : public ZoneHashMap {
   Zone* zone() const { return allocator().zone(); }
 };
 
-class Scope;
-
-template <>
-struct PointerWithPayloadTraits<Scope> {
-  static constexpr int value = 1;
-};
-
 // Global invariants after AST construction: Each reference (i.e. identifier)
 // to a JavaScript variable (including global properties) is represented by a
 // VariableProxy node. Immediately after AST construction and before variable
@@ -155,7 +160,7 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
     // Upon move assignment we store whether the new inner scope calls eval into
     // the move target calls_eval bit, and restore calls eval on the outer
     // scope.
-    PointerWithPayload<Scope, bool, 1> outer_scope_and_calls_eval_;
+    base::PointerWithPayload<Scope, bool, 1> outer_scope_and_calls_eval_;
     Scope* top_inner_scope_;
     UnresolvedList::Iterator top_unresolved_;
     base::ThreadedList<Variable>::Iterator top_local_;
@@ -1548,7 +1553,8 @@ class V8_EXPORT_PRIVATE ClassScope : public Scope {
     rare_data_and_is_parsing_heritage_.SetPayload(v);
   }
 
-  PointerWithPayload<RareData, bool, 1> rare_data_and_is_parsing_heritage_;
+  base::PointerWithPayload<RareData, bool, 1>
+      rare_data_and_is_parsing_heritage_;
   Variable* class_variable_ = nullptr;
   // These are only maintained when the scope is parsed, not when the
   // scope is deserialized.

src/utils/pointer-with-payload.h → src/base/pointer-with-payload.h

@@ -2,21 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef V8_UTILS_POINTER_WITH_PAYLOAD_H_
-#define V8_UTILS_POINTER_WITH_PAYLOAD_H_
+#ifndef V8_BASE_POINTER_WITH_PAYLOAD_H_
+#define V8_BASE_POINTER_WITH_PAYLOAD_H_
 
 #include <cstdint>
 #include <type_traits>
 
-#include "include/v8config.h"
 #include "src/base/logging.h"
 
 namespace v8 {
-namespace internal {
+namespace base {
 
 template <typename PointerType>
 struct PointerWithPayloadTraits {
-  static constexpr int value =
+  static constexpr int kAvailableBits =
       alignof(PointerType) >= 8 ? 3 : alignof(PointerType) >= 4 ? 2 : 1;
 };
 
@@ -37,82 +36,83 @@ struct PointerWithPayloadTraits<void> : public PointerWithPayloadTraits<void*> {
 //
 //   Here we store a bool that needs 1 bit of storage state into the lower bits
 //   of int *, which points to some int data;
-
 template <typename PointerType, typename PayloadType, int NumPayloadBits>
 class PointerWithPayload {
-  // We have log2(ptr alignment) kAvailBits free to use
-  static constexpr int kAvailBits = PointerWithPayloadTraits<
-      typename std::remove_const<PointerType>::type>::value;
-  static_assert(
-      kAvailBits >= NumPayloadBits,
-      "Ptr does not have sufficient alignment for the selected amount of "
-      "storage bits.");
-
-  static constexpr uintptr_t kPayloadMask =
-      (uintptr_t{1} << NumPayloadBits) - 1;
-  static constexpr uintptr_t kPointerMask = ~kPayloadMask;
-
  public:
   PointerWithPayload() = default;
 
   explicit PointerWithPayload(PointerType* pointer)
-      : pointer_(reinterpret_cast<uintptr_t>(pointer)) {
+      : pointer_with_payload_(reinterpret_cast<uintptr_t>(pointer)) {
     DCHECK_EQ(GetPointer(), pointer);
     DCHECK_EQ(GetPayload(), static_cast<PayloadType>(0));
   }
 
   explicit PointerWithPayload(PayloadType payload)
-      : pointer_(static_cast<uintptr_t>(payload)) {
+      : pointer_with_payload_(static_cast<uintptr_t>(payload)) {
     DCHECK_EQ(GetPointer(), nullptr);
     DCHECK_EQ(GetPayload(), payload);
   }
 
   PointerWithPayload(PointerType* pointer, PayloadType payload) {
-    update(pointer, payload);
+    Update(pointer, payload);
   }
 
   V8_INLINE PointerType* GetPointer() const {
-    return reinterpret_cast<PointerType*>(pointer_ & kPointerMask);
+    return reinterpret_cast<PointerType*>(pointer_with_payload_ & kPointerMask);
   }
 
   // An optimized version of GetPointer for when we know the payload value.
   V8_INLINE PointerType* GetPointerWithKnownPayload(PayloadType payload) const {
     DCHECK_EQ(GetPayload(), payload);
-    return reinterpret_cast<PointerType*>(pointer_ -
+    return reinterpret_cast<PointerType*>(pointer_with_payload_ -
                                           static_cast<uintptr_t>(payload));
   }
 
   V8_INLINE PointerType* operator->() const { return GetPointer(); }
 
-  V8_INLINE void update(PointerType* new_pointer, PayloadType new_payload) {
-    pointer_ = reinterpret_cast<uintptr_t>(new_pointer) |
-               static_cast<uintptr_t>(new_payload);
+  V8_INLINE void Update(PointerType* new_pointer, PayloadType new_payload) {
+    pointer_with_payload_ = reinterpret_cast<uintptr_t>(new_pointer) |
+                            static_cast<uintptr_t>(new_payload);
     DCHECK_EQ(GetPayload(), new_payload);
     DCHECK_EQ(GetPointer(), new_pointer);
   }
 
   V8_INLINE void SetPointer(PointerType* newptr) {
     DCHECK_EQ(reinterpret_cast<uintptr_t>(newptr) & kPayloadMask, 0);
-    pointer_ = reinterpret_cast<uintptr_t>(newptr) | (pointer_ & kPayloadMask);
+    pointer_with_payload_ = reinterpret_cast<uintptr_t>(newptr) |
+                            (pointer_with_payload_ & kPayloadMask);
     DCHECK_EQ(GetPointer(), newptr);
   }
 
   V8_INLINE PayloadType GetPayload() const {
-    return static_cast<PayloadType>(pointer_ & kPayloadMask);
+    return static_cast<PayloadType>(pointer_with_payload_ & kPayloadMask);
   }
 
   V8_INLINE void SetPayload(PayloadType new_payload) {
     uintptr_t new_payload_ptr = static_cast<uintptr_t>(new_payload);
     DCHECK_EQ(new_payload_ptr & kPayloadMask, new_payload_ptr);
-    pointer_ = (pointer_ & kPointerMask) | new_payload_ptr;
+    pointer_with_payload_ =
+        (pointer_with_payload_ & kPointerMask) | new_payload_ptr;
     DCHECK_EQ(GetPayload(), new_payload);
   }
 
  private:
-  uintptr_t pointer_ = 0;
+  static constexpr int kAvailableBits = PointerWithPayloadTraits<
+      typename std::remove_const<PointerType>::type>::kAvailableBits;
+  static_assert(
+      kAvailableBits >= NumPayloadBits,
+      "Ptr does not have sufficient alignment for the selected amount of "
+      "storage bits. Override PointerWithPayloadTraits to guarantee available "
+      "bits manually.");
+
+  static constexpr uintptr_t kPayloadMask =
+      (uintptr_t{1} << NumPayloadBits) - 1;
+  static constexpr uintptr_t kPointerMask = ~kPayloadMask;
+
+  uintptr_t pointer_with_payload_ = 0;
 };
 
-}  // namespace internal
+}  // namespace base
 }  // namespace v8
 
-#endif  // V8_UTILS_POINTER_WITH_PAYLOAD_H_
+#endif  // V8_BASE_POINTER_WITH_PAYLOAD_H_

src/maglev/maglev-regalloc-data.h

@@ -5,9 +5,9 @@
 #ifndef V8_MAGLEV_MAGLEV_REGALLOC_DATA_H_
 #define V8_MAGLEV_MAGLEV_REGALLOC_DATA_H_
 
+#include "src/base/pointer-with-payload.h"
 #include "src/codegen/register.h"
 #include "src/compiler/backend/instruction.h"
-#include "src/utils/pointer-with-payload.h"
 
 namespace v8 {
 namespace internal {
@@ -70,7 +70,7 @@ constexpr bool operator==(const RegisterStateFlags& left,
          left.is_merge == right.is_merge;
 }
 
-typedef PointerWithPayload<void, RegisterStateFlags, 2> RegisterState;
+typedef base::PointerWithPayload<void, RegisterStateFlags, 2> RegisterState;
 
 struct RegisterMerge {
   compiler::AllocatedOperand* operands() {

src/parsing/func-name-inferrer.h

@@ -8,23 +8,29 @@
 #include <vector>
 
 #include "src/base/macros.h"
-#include "src/utils/pointer-with-payload.h"
+#include "src/base/pointer-with-payload.h"
 
 namespace v8 {
+
+namespace internal {
+class AstRawString;
+}
+
+namespace base {
+template <>
+struct PointerWithPayloadTraits<v8::internal::AstRawString> {
+  static constexpr int kAvailableBits = 2;
+};
+}  // namespace base
+
 namespace internal {
 
 class AstConsString;
-class AstRawString;
 class AstValueFactory;
 class FunctionLiteral;
 
 enum class InferName { kYes, kNo };
 
-template <>
-struct PointerWithPayloadTraits<AstRawString> {
-  static constexpr int value = 2;
-};
-
 // FuncNameInferrer is a stateful class that is used to perform name
 // inference for anonymous functions during static analysis of source code.
 // Inference is performed in cases when an anonymous function is assigned
@@ -105,7 +111,7 @@ class FuncNameInferrer {
     Name(const AstRawString* name, NameType type)
         : name_and_type_(name, type) {}
 
-    PointerWithPayload<const AstRawString, NameType, 2> name_and_type_;
+    base::PointerWithPayload<const AstRawString, NameType, 2> name_and_type_;
     inline const AstRawString* name() const {
       return name_and_type_.GetPointer();
     }

src/parsing/parser-base.h

@@ -15,6 +15,7 @@
 #include "src/ast/scopes.h"
 #include "src/base/flags.h"
 #include "src/base/hashmap.h"
+#include "src/base/pointer-with-payload.h"
 #include "src/base/v8-fallthrough.h"
 #include "src/codegen/bailout-reason.h"
 #include "src/common/globals.h"
@@ -28,7 +29,6 @@
 #include "src/parsing/scanner.h"
 #include "src/parsing/token.h"
 #include "src/regexp/regexp.h"
-#include "src/utils/pointer-with-payload.h"
 #include "src/zone/zone-chunk-list.h"
 
 namespace v8 {
@@ -482,7 +482,7 @@ class ParserBase {
       }
 
      private:
-      PointerWithPayload<FunctionState, bool, 1> state_and_prev_value_;
+      base::PointerWithPayload<FunctionState, bool, 1> state_and_prev_value_;
     };
 
     class V8_NODISCARD LoopScope final {

src/parsing/parser.h

@@ -12,6 +12,7 @@
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/base/compiler-specific.h"
+#include "src/base/pointer-with-payload.h"
 #include "src/base/small-vector.h"
 #include "src/base/threaded-list.h"
 #include "src/common/globals.h"
@@ -20,7 +21,6 @@
 #include "src/parsing/parser-base.h"
 #include "src/parsing/parsing.h"
 #include "src/parsing/preparser.h"
-#include "src/utils/pointer-with-payload.h"
 #include "src/zone/zone-chunk-list.h"
 
 namespace v8 {
@@ -51,7 +51,7 @@ struct ParserFormalParameters : FormalParametersBase {
           position(position),
           initializer_end_position(initializer_end_position) {}
 
-    PointerWithPayload<Expression, bool, 1> initializer_and_is_rest;
+    base::PointerWithPayload<Expression, bool, 1> initializer_and_is_rest;
 
     Expression* pattern;
     Expression* initializer() const {

src/parsing/scanner.h

@@ -21,7 +21,6 @@
 #include "src/strings/char-predicates.h"
 #include "src/strings/unicode.h"
 #include "src/utils/allocation.h"
-#include "src/utils/pointer-with-payload.h"
 
 namespace v8 {
 namespace internal {