Reland "[snapshot] Extract more files"

This is a reland of 5c4b8056

Original change's description:
> [snapshot] Extract more files
>
> This moves:
>
> - ExternalReferenceEncoder to codegen/external-reference-encoder.h
> - SerializerDeserializer to snapshot/serializer-deserializer.h
> - Checksum() to snapshot/snapshot-utils.h
>
> serializer-common.h and .cc are removed.
>
> Tbr: clemensb@chromium.org,ulan@chromium.org
> Bug: v8:10416
> Change-Id: I36a242dcc1ad8833374aa567f73e0d4a75632c58
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2144118
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Dan Elphick <delphick@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#67281}

Tbr: delphick@chromium.org,clemensb@chromium.org,ulan@chromium.org
Bug: v8:10416
Change-Id: I6f6a1017435db185778ed931e1ddb13d8d5e920e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2157384Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67298}

BUILD.gn

@@ -2189,6 +2189,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/codegen/constant-pool.h",
     "src/codegen/constants-arch.h",
     "src/codegen/cpu-features.h",
+    "src/codegen/external-reference-encoder.cc",
+    "src/codegen/external-reference-encoder.h",
     "src/codegen/external-reference-table.cc",
     "src/codegen/external-reference-table.h",
     "src/codegen/external-reference.cc",
@@ -2956,8 +2958,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/snapshot/roots-serializer.h",
     "src/snapshot/serializer-allocator.cc",
     "src/snapshot/serializer-allocator.h",
-    "src/snapshot/serializer-common.cc",
-    "src/snapshot/serializer-common.h",
+    "src/snapshot/serializer-deserializer.cc",
+    "src/snapshot/serializer-deserializer.h",
     "src/snapshot/serializer.cc",
     "src/snapshot/serializer.h",
     "src/snapshot/snapshot-compression.cc",
@@ -2966,6 +2968,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/snapshot/snapshot-data.h",
     "src/snapshot/snapshot-source-sink.cc",
     "src/snapshot/snapshot-source-sink.h",
+    "src/snapshot/snapshot-utils.cc",
+    "src/snapshot/snapshot-utils.h",
     "src/snapshot/snapshot.cc",
     "src/snapshot/snapshot.h",
     "src/snapshot/startup-deserializer.cc",

src/codegen/assembler.cc

@@ -41,7 +41,6 @@
 #include "src/execution/isolate.h"
 #include "src/heap/heap-inl.h"  // For MemoryAllocator. TODO(jkummerow): Drop.
 #include "src/snapshot/embedded/embedded-data.h"
-#include "src/snapshot/serializer-common.h"
 #include "src/snapshot/snapshot.h"
 #include "src/utils/ostreams.h"
 #include "src/utils/vector.h"

src/snapshot/serializer-common.cc → src/codegen/external-reference-encoder.cc

-// Copyright 2016 the V8 project authors. All rights reserved.
+// 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.
 
-#include "src/snapshot/serializer-common.h"
+#include "src/codegen/external-reference-encoder.h"
 
 #include "src/codegen/external-reference-table.h"
-#include "src/objects/foreign-inl.h"
-#include "src/objects/objects-inl.h"
-#include "src/objects/slots.h"
-#include "third_party/zlib/zlib.h"
+#include "src/execution/isolate.h"
 
 namespace v8 {
 namespace internal {
@@ -45,8 +42,8 @@ ExternalReferenceEncoder::ExternalReferenceEncoder(Isolate* isolate) {
   }
 }
 
-ExternalReferenceEncoder::~ExternalReferenceEncoder() {
 #ifdef DEBUG
+ExternalReferenceEncoder::~ExternalReferenceEncoder() {
   if (!i::FLAG_external_reference_stats) return;
   if (api_references_ == nullptr) return;
   for (uint32_t i = 0; api_references_[i] != 0; ++i) {
@@ -56,8 +53,8 @@ ExternalReferenceEncoder::~ExternalReferenceEncoder() {
         "index=%5d count=%5d  %-60s\n", i, count_[i],
         ExternalReferenceTable::ResolveSymbol(reinterpret_cast<void*>(addr)));
   }
-#endif  // DEBUG
 }
+#endif  // DEBUG
 
 Maybe<ExternalReferenceEncoder::Value> ExternalReferenceEncoder::TryEncode(
     Address address) {
@@ -96,63 +93,5 @@ const char* ExternalReferenceEncoder::NameOfAddress(Isolate* isolate,
   return isolate->external_reference_table()->name(value.index());
 }
 
-// The partial snapshot cache is terminated by undefined. We visit the
-// partial snapshot...
-//  - during deserialization to populate it.
-//  - during normal GC to keep its content alive.
-//  - not during serialization. The partial serializer adds to it explicitly.
-DISABLE_CFI_PERF
-void SerializerDeserializer::Iterate(Isolate* isolate, RootVisitor* visitor) {
-  std::vector<Object>* cache = isolate->partial_snapshot_cache();
-  for (size_t i = 0;; ++i) {
-    // Extend the array ready to get a value when deserializing.
-    if (cache->size() <= i) cache->push_back(Smi::zero());
-    // During deserialization, the visitor populates the partial snapshot cache
-    // and eventually terminates the cache with undefined.
-    visitor->VisitRootPointer(Root::kPartialSnapshotCache, nullptr,
-                              FullObjectSlot(&cache->at(i)));
-    if (cache->at(i).IsUndefined(isolate)) break;
-  }
-}
-
-bool SerializerDeserializer::CanBeDeferred(HeapObject o) {
-  // ArrayBuffer instances are serialized by first re-assigning a index
-  // to the backing store field, then serializing the object, and then
-  // storing the actual backing store address again (and the same for the
-  // ArrayBufferExtension). If serialization of the object itself is deferred,
-  // the real backing store address is written into the snapshot, which cannot
-  // be processed when deserializing.
-  return !o.IsString() && !o.IsScript() && !o.IsJSTypedArray() &&
-         !o.IsJSArrayBuffer();
-}
-
-void SerializerDeserializer::RestoreExternalReferenceRedirectors(
-    const std::vector<AccessorInfo>& accessor_infos) {
-  // Restore wiped accessor infos.
-  for (AccessorInfo info : accessor_infos) {
-    Foreign::cast(info.js_getter())
-        .set_foreign_address(info.redirected_getter());
-  }
-}
-
-void SerializerDeserializer::RestoreExternalReferenceRedirectors(
-    const std::vector<CallHandlerInfo>& call_handler_infos) {
-  for (CallHandlerInfo info : call_handler_infos) {
-    Foreign::cast(info.js_callback())
-        .set_foreign_address(info.redirected_callback());
-  }
-}
-
-uint32_t Checksum(Vector<const byte> payload) {
-#ifdef MEMORY_SANITIZER
-  // Computing the checksum includes padding bytes for objects like strings.
-  // Mark every object as initialized in the code serializer.
-  MSAN_MEMORY_IS_INITIALIZED(payload.begin(), payload.length());
-#endif  // MEMORY_SANITIZER
-  // Priming the adler32 call so it can see what CPU features are available.
-  adler32(0, NULL, 0);
-  return static_cast<uint32_t>(adler32(0, payload.begin(), payload.length()));
-}
-
 }  // namespace internal
 }  // namespace v8

src/codegen/external-reference-encoder.h

+// 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_CODEGEN_EXTERNAL_REFERENCE_ENCODER_H_
+#define V8_CODEGEN_EXTERNAL_REFERENCE_ENCODER_H_
+
+#include "src/base/bit-field.h"
+#include "src/common/globals.h"
+#include "src/utils/address-map.h"
+
+namespace v8 {
+namespace internal {
+
+class Isolate;
+
+class ExternalReferenceEncoder {
+ public:
+  class Value {
+   public:
+    explicit Value(uint32_t raw) : value_(raw) {}
+    Value() : value_(0) {}
+    static uint32_t Encode(uint32_t index, bool is_from_api) {
+      return Index::encode(index) | IsFromAPI::encode(is_from_api);
+    }
+
+    bool is_from_api() const { return IsFromAPI::decode(value_); }
+    uint32_t index() const { return Index::decode(value_); }
+
+   private:
+    using Index = base::BitField<uint32_t, 0, 31>;
+    using IsFromAPI = base::BitField<bool, 31, 1>;
+    uint32_t value_;
+  };
+
+  explicit ExternalReferenceEncoder(Isolate* isolate);
+#ifdef DEBUG
+  ~ExternalReferenceEncoder();
+#endif  // DEBUG
+
+  Value Encode(Address key);
+  Maybe<Value> TryEncode(Address key);
+
+  const char* NameOfAddress(Isolate* isolate, Address address) const;
+
+ private:
+  AddressToIndexHashMap* map_;
+
+#ifdef DEBUG
+  std::vector<int> count_;
+  const intptr_t* api_references_;
+#endif  // DEBUG
+
+  DISALLOW_COPY_AND_ASSIGN(ExternalReferenceEncoder);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_CODEGEN_EXTERNAL_REFERENCE_ENCODER_H_

src/codegen/reloc-info.cc

@@ -6,12 +6,12 @@
 
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/code-reference.h"
+#include "src/codegen/external-reference-encoder.h"
 #include "src/deoptimizer/deoptimize-reason.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/heap/heap-write-barrier-inl.h"
 #include "src/objects/code-inl.h"
 #include "src/snapshot/embedded/embedded-data.h"
-#include "src/snapshot/serializer-common.h"  // For ExternalReferenceEncoder.
 
 namespace v8 {
 namespace internal {

src/codegen/turbo-assembler.cc

@@ -6,9 +6,9 @@
 
 #include "src/builtins/builtins.h"
 #include "src/builtins/constants-table-builder.h"
+#include "src/codegen/external-reference-encoder.h"
 #include "src/execution/isolate-data.h"
 #include "src/execution/isolate-inl.h"
-#include "src/snapshot/serializer-common.h"
 
 namespace v8 {
 namespace internal {

src/diagnostics/disassembler.cc

@@ -12,6 +12,7 @@
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/code-comments.h"
 #include "src/codegen/code-reference.h"
+#include "src/codegen/external-reference-encoder.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
@@ -20,7 +21,6 @@
 #include "src/ic/ic.h"
 #include "src/objects/objects-inl.h"
 #include "src/snapshot/embedded/embedded-data.h"
-#include "src/snapshot/serializer-common.h"
 #include "src/strings/string-stream.h"
 #include "src/utils/vector.h"
 #include "src/wasm/wasm-code-manager.h"

src/execution/isolate.cc

@@ -80,6 +80,7 @@
 #include "src/tasks/cancelable-task.h"
 #include "src/tracing/tracing-category-observer.h"
 #include "src/trap-handler/trap-handler.h"
+#include "src/utils/address-map.h"
 #include "src/utils/ostreams.h"
 #include "src/utils/version.h"
 #include "src/wasm/wasm-code-manager.h"

src/heap/heap.cc

@@ -71,7 +71,7 @@
 #include "src/objects/slots-inl.h"
 #include "src/regexp/regexp.h"
 #include "src/snapshot/embedded/embedded-data.h"
-#include "src/snapshot/serializer-common.h"
+#include "src/snapshot/serializer-deserializer.h"
 #include "src/snapshot/snapshot.h"
 #include "src/strings/string-stream.h"
 #include "src/strings/unicode-decoder.h"

src/snapshot/DEPS

@@ -5,7 +5,7 @@ specific_include_rules = {
   "snapshot-compression.cc": [
     "+third_party/zlib",
   ],
-  "serializer-common.cc": [
+  "snapshot-utils.cc": [
     "+third_party/zlib",
   ],
 }

src/snapshot/code-serializer.cc

@@ -13,6 +13,7 @@
 #include "src/objects/slots.h"
 #include "src/objects/visitors.h"
 #include "src/snapshot/object-deserializer.h"
+#include "src/snapshot/snapshot-utils.h"
 #include "src/snapshot/snapshot.h"
 #include "src/utils/version.h"
 

src/snapshot/deserializer-allocator.h

@@ -8,7 +8,7 @@
 #include "src/common/globals.h"
 #include "src/heap/heap.h"
 #include "src/objects/heap-object.h"
-#include "src/snapshot/serializer-common.h"
+#include "src/snapshot/references.h"
 #include "src/snapshot/snapshot-data.h"
 
 namespace v8 {

src/snapshot/deserializer.h

@@ -16,7 +16,7 @@
 #include "src/objects/map.h"
 #include "src/objects/string.h"
 #include "src/snapshot/deserializer-allocator.h"
-#include "src/snapshot/serializer-common.h"
+#include "src/snapshot/serializer-deserializer.h"
 #include "src/snapshot/snapshot-source-sink.h"
 
 namespace v8 {

src/snapshot/serializer-allocator.h

@@ -5,7 +5,7 @@
 #ifndef V8_SNAPSHOT_SERIALIZER_ALLOCATOR_H_
 #define V8_SNAPSHOT_SERIALIZER_ALLOCATOR_H_
 
-#include "src/snapshot/serializer-common.h"
+#include "src/snapshot/references.h"
 #include "src/snapshot/snapshot-data.h"
 
 namespace v8 {

src/snapshot/serializer-deserializer.cc

+// 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.
+
+#include "src/snapshot/serializer-deserializer.h"
+
+#include "src/objects/foreign-inl.h"
+#include "src/objects/objects-inl.h"
+
+namespace v8 {
+namespace internal {
+
+// The partial snapshot cache is terminated by undefined. We visit the
+// partial snapshot...
+//  - during deserialization to populate it.
+//  - during normal GC to keep its content alive.
+//  - not during serialization. The partial serializer adds to it explicitly.
+DISABLE_CFI_PERF
+void SerializerDeserializer::Iterate(Isolate* isolate, RootVisitor* visitor) {
+  std::vector<Object>* cache = isolate->partial_snapshot_cache();
+  for (size_t i = 0;; ++i) {
+    // Extend the array ready to get a value when deserializing.
+    if (cache->size() <= i) cache->push_back(Smi::zero());
+    // During deserialization, the visitor populates the partial snapshot cache
+    // and eventually terminates the cache with undefined.
+    visitor->VisitRootPointer(Root::kPartialSnapshotCache, nullptr,
+                              FullObjectSlot(&cache->at(i)));
+    if (cache->at(i).IsUndefined(isolate)) break;
+  }
+}
+
+bool SerializerDeserializer::CanBeDeferred(HeapObject o) {
+  // ArrayBuffer instances are serialized by first re-assigning a index
+  // to the backing store field, then serializing the object, and then
+  // storing the actual backing store address again (and the same for the
+  // ArrayBufferExtension). If serialization of the object itself is deferred,
+  // the real backing store address is written into the snapshot, which cannot
+  // be processed when deserializing.
+  return !o.IsString() && !o.IsScript() && !o.IsJSTypedArray() &&
+         !o.IsJSArrayBuffer();
+}
+
+void SerializerDeserializer::RestoreExternalReferenceRedirectors(
+    const std::vector<AccessorInfo>& accessor_infos) {
+  // Restore wiped accessor infos.
+  for (AccessorInfo info : accessor_infos) {
+    Foreign::cast(info.js_getter())
+        .set_foreign_address(info.redirected_getter());
+  }
+}
+
+void SerializerDeserializer::RestoreExternalReferenceRedirectors(
+    const std::vector<CallHandlerInfo>& call_handler_infos) {
+  for (CallHandlerInfo info : call_handler_infos) {
+    Foreign::cast(info.js_callback())
+        .set_foreign_address(info.redirected_callback());
+  }
+}
+
+}  // namespace internal
+}  // namespace v8

src/snapshot/serializer-common.h → src/snapshot/serializer-deserializer.h

-// Copyright 2016 the V8 project authors. All rights reserved.
+// 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_SNAPSHOT_SERIALIZER_COMMON_H_
-#define V8_SNAPSHOT_SERIALIZER_COMMON_H_
+#ifndef V8_SNAPSHOT_SERIALIZER_DESERIALIZER_H_
+#define V8_SNAPSHOT_SERIALIZER_DESERIALIZER_H_
 
-#include "src/base/bits.h"
-#include "src/base/memory.h"
-#include "src/codegen/external-reference-table.h"
-#include "src/common/globals.h"
 #include "src/objects/visitors.h"
-#include "src/sanitizer/msan.h"
 #include "src/snapshot/references.h"
-#include "src/utils/address-map.h"
 
 namespace v8 {
 namespace internal {
@@ -20,89 +14,51 @@ namespace internal {
 class CallHandlerInfo;
 class Isolate;
 
-class ExternalReferenceEncoder {
+// The Serializer/Deserializer class is a common superclass for Serializer and
+// Deserializer which is used to store common constants and methods used by
+// both.
+class SerializerDeserializer : public RootVisitor {
  public:
-  class Value {
-   public:
-    explicit Value(uint32_t raw) : value_(raw) {}
-    Value() : value_(0) {}
-    static uint32_t Encode(uint32_t index, bool is_from_api) {
-      return Index::encode(index) | IsFromAPI::encode(is_from_api);
-    }
-
-    bool is_from_api() const { return IsFromAPI::decode(value_); }
-    uint32_t index() const { return Index::decode(value_); }
-
-   private:
-    using Index = base::BitField<uint32_t, 0, 31>;
-    using IsFromAPI = base::BitField<bool, 31, 1>;
-    uint32_t value_;
-  };
-
-  explicit ExternalReferenceEncoder(Isolate* isolate);
-  ~ExternalReferenceEncoder();  // NOLINT (modernize-use-equals-default)
-
-  Value Encode(Address key);
-  Maybe<Value> TryEncode(Address key);
-
-  const char* NameOfAddress(Isolate* isolate, Address address) const;
-
- private:
-  AddressToIndexHashMap* map_;
-
-#ifdef DEBUG
-  std::vector<int> count_;
-  const intptr_t* api_references_;
-#endif  // DEBUG
-
-  DISALLOW_COPY_AND_ASSIGN(ExternalReferenceEncoder);
-};
+  static void Iterate(Isolate* isolate, RootVisitor* visitor);
 
-class HotObjectsList {
- public:
-  HotObjectsList() : index_(0) {}
+ protected:
+  class HotObjectsList {
+   public:
+    HotObjectsList() = default;
 
-  void Add(HeapObject object) {
-    DCHECK(!AllowHeapAllocation::IsAllowed());
-    circular_queue_[index_] = object;
-    index_ = (index_ + 1) & kSizeMask;
-  }
+    void Add(HeapObject object) {
+      DCHECK(!AllowHeapAllocation::IsAllowed());
+      circular_queue_[index_] = object;
+      index_ = (index_ + 1) & kSizeMask;
+    }
 
-  HeapObject Get(int index) {
-    DCHECK(!AllowHeapAllocation::IsAllowed());
-    DCHECK(!circular_queue_[index].is_null());
-    return circular_queue_[index];
-  }
+    HeapObject Get(int index) {
+      DCHECK(!AllowHeapAllocation::IsAllowed());
+      DCHECK(!circular_queue_[index].is_null());
+      return circular_queue_[index];
+    }
 
-  static const int kNotFound = -1;
+    static const int kNotFound = -1;
 
-  int Find(HeapObject object) {
-    DCHECK(!AllowHeapAllocation::IsAllowed());
-    for (int i = 0; i < kSize; i++) {
-      if (circular_queue_[i] == object) return i;
+    int Find(HeapObject object) {
+      DCHECK(!AllowHeapAllocation::IsAllowed());
+      for (int i = 0; i < kSize; i++) {
+        if (circular_queue_[i] == object) return i;
+      }
+      return kNotFound;
     }
-    return kNotFound;
-  }
-
-  static const int kSize = 8;
 
- private:
-  static_assert(base::bits::IsPowerOfTwo(kSize), "kSize must be power of two");
-  static const int kSizeMask = kSize - 1;
-  HeapObject circular_queue_[kSize];
-  int index_;
+    static const int kSize = 8;
 
-  DISALLOW_COPY_AND_ASSIGN(HotObjectsList);
-};
+   private:
+    STATIC_ASSERT(base::bits::IsPowerOfTwo(kSize));
+    static const int kSizeMask = kSize - 1;
+    HeapObject circular_queue_[kSize];
+    int index_ = 0;
 
-// The Serializer/Deserializer class is a common superclass for Serializer and
-// Deserializer which is used to store common constants and methods used by
-// both.
-class SerializerDeserializer : public RootVisitor {
- public:
-  static void Iterate(Isolate* isolate, RootVisitor* visitor);
+    DISALLOW_COPY_AND_ASSIGN(HotObjectsList);
+  };
 
- protected:
   static bool CanBeDeferred(HeapObject o);
 
   void RestoreExternalReferenceRedirectors(
@@ -293,9 +249,7 @@ class SerializerDeserializer : public RootVisitor {
   HotObjectsList hot_objects_;
 };
 
-V8_EXPORT_PRIVATE uint32_t Checksum(Vector<const byte> payload);
-
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_SNAPSHOT_SERIALIZER_COMMON_H_
+#endif  // V8_SNAPSHOT_SERIALIZER_DESERIALIZER_H_

src/snapshot/serializer.h

@@ -7,12 +7,13 @@
 
 #include <map>
 
+#include "src/codegen/external-reference-encoder.h"
 #include "src/execution/isolate.h"
 #include "src/logging/log.h"
 #include "src/objects/objects.h"
 #include "src/snapshot/embedded/embedded-data.h"
 #include "src/snapshot/serializer-allocator.h"
-#include "src/snapshot/serializer-common.h"
+#include "src/snapshot/serializer-deserializer.h"
 #include "src/snapshot/snapshot-source-sink.h"
 
 namespace v8 {

src/snapshot/snapshot-compression.cc

@@ -4,7 +4,9 @@
 
 #include "src/snapshot/snapshot-compression.h"
 
+#include "src/base/platform/elapsed-timer.h"
 #include "src/utils/memcopy.h"
+#include "src/utils/utils.h"
 #include "third_party/zlib/google/compression_utils_portable.h"
 
 namespace v8 {

src/snapshot/snapshot-compression.h

@@ -5,9 +5,7 @@
 #ifndef V8_SNAPSHOT_SNAPSHOT_COMPRESSION_H_
 #define V8_SNAPSHOT_SNAPSHOT_COMPRESSION_H_
 
-#include "src/snapshot/serializer-common.h"
-#include "src/snapshot/serializer.h"
-#include "src/snapshot/snapshot.h"
+#include "src/snapshot/snapshot-data.h"
 #include "src/utils/vector.h"
 
 namespace v8 {

src/snapshot/snapshot-source-sink.h

@@ -8,7 +8,7 @@
 #include <utility>
 
 #include "src/base/logging.h"
-#include "src/snapshot/serializer-common.h"
+#include "src/snapshot/snapshot-utils.h"
 #include "src/utils/utils.h"
 
 namespace v8 {

src/snapshot/snapshot-utils.cc

+// 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.
+
+#include "src/snapshot/snapshot-utils.h"
+
+#include "src/sanitizer/msan.h"
+#include "third_party/zlib/zlib.h"
+
+namespace v8 {
+namespace internal {
+
+uint32_t Checksum(Vector<const byte> payload) {
+#ifdef MEMORY_SANITIZER
+  // Computing the checksum includes padding bytes for objects like strings.
+  // Mark every object as initialized in the code serializer.
+  MSAN_MEMORY_IS_INITIALIZED(payload.begin(), payload.length());
+#endif  // MEMORY_SANITIZER
+  // Priming the adler32 call so it can see what CPU features are available.
+  adler32(0, NULL, 0);
+  return static_cast<uint32_t>(adler32(0, payload.begin(), payload.length()));
+}
+
+}  // namespace internal
+}  // namespace v8

src/snapshot/snapshot-utils.h

+// 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_SNAPSHOT_SNAPSHOT_UTILS_H_
+#define V8_SNAPSHOT_SNAPSHOT_UTILS_H_
+
+#include "src/utils/vector.h"
+
+namespace v8 {
+namespace internal {
+
+V8_EXPORT_PRIVATE uint32_t Checksum(Vector<const byte> payload);
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_SNAPSHOT_SNAPSHOT_UTILS_H_

src/snapshot/snapshot.cc

@@ -10,6 +10,7 @@
 #include "src/logging/counters.h"
 #include "src/snapshot/partial-deserializer.h"
 #include "src/snapshot/read-only-deserializer.h"
+#include "src/snapshot/snapshot-utils.h"
 #include "src/snapshot/startup-deserializer.h"
 #include "src/utils/memcopy.h"
 #include "src/utils/version.h"

src/wasm/wasm-serialization.cc

@@ -10,7 +10,6 @@
 #include "src/objects/objects.h"
 #include "src/runtime/runtime.h"
 #include "src/snapshot/code-serializer.h"
-#include "src/snapshot/serializer-common.h"
 #include "src/utils/ostreams.h"
 #include "src/utils/utils.h"
 #include "src/utils/version.h"