[ptr-compr] Support decompression in include/v8.h and include/v8-internal.h

Bug: v8:7703
Change-Id: I2cc5ceb7b70a9b53d5bcc90b32276c011f89ffbe
Reviewed-on: https://chromium-review.googlesource.com/c/1388530
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58476}

include/v8-internal.h

@@ -209,12 +209,12 @@ class Internals {
 
   V8_INLINE static int GetInstanceType(const internal::Address obj) {
     typedef internal::Address A;
-    A map = ReadField<A>(obj, kHeapObjectMapOffset);
-    return ReadField<uint16_t>(map, kMapInstanceTypeOffset);
+    A map = ReadTaggedPointerField(obj, kHeapObjectMapOffset);
+    return ReadRawField<uint16_t>(map, kMapInstanceTypeOffset);
   }
 
   V8_INLINE static int GetOddballKind(const internal::Address obj) {
-    return SmiValue(ReadField<internal::Address>(obj, kOddballKindOffset));
+    return SmiValue(ReadTaggedSignedField(obj, kOddballKindOffset));
   }
 
   V8_INLINE static bool IsExternalTwoByteString(int instance_type) {
@@ -268,24 +268,74 @@ class Internals {
   }
 
   template <typename T>
-  V8_INLINE static T ReadField(const internal::Address heap_object_ptr,
+  V8_INLINE static T ReadRawField(internal::Address heap_object_ptr,
                                   int offset) {
     internal::Address addr = heap_object_ptr + offset - kHeapObjectTag;
     return *reinterpret_cast<const T*>(addr);
   }
 
-#ifndef V8_COMPRESS_POINTERS
+  V8_INLINE static internal::Address ReadTaggedPointerField(
+      internal::Address heap_object_ptr, int offset) {
+#ifdef V8_COMPRESS_POINTERS
+    int32_t value = ReadRawField<int32_t>(heap_object_ptr, offset);
+    internal::Address root = GetRootFromOnHeapAddress(heap_object_ptr);
+    return root + static_cast<internal::Address>(static_cast<intptr_t>(value));
+#else
+    return ReadRawField<internal::Address>(heap_object_ptr, offset);
+#endif
+  }
+
+  V8_INLINE static internal::Address ReadTaggedSignedField(
+      internal::Address heap_object_ptr, int offset) {
+#ifdef V8_COMPRESS_POINTERS
+    int32_t value = ReadRawField<int32_t>(heap_object_ptr, offset);
+    return static_cast<internal::Address>(static_cast<intptr_t>(value));
+#else
+    return ReadRawField<internal::Address>(heap_object_ptr, offset);
+#endif
+  }
+
+  V8_INLINE static internal::Address ReadTaggedAnyField(
+      internal::Address heap_object_ptr, int offset) {
+#ifdef V8_COMPRESS_POINTERS
+    int32_t value = ReadRawField<int32_t>(heap_object_ptr, offset);
+    internal::Address root_mask = static_cast<internal::Address>(
+        -static_cast<intptr_t>(value & kSmiTagMask));
+    internal::Address root_or_zero =
+        root_mask & GetRootFromOnHeapAddress(heap_object_ptr);
+    return root_or_zero +
+           static_cast<internal::Address>(static_cast<intptr_t>(value));
+#else
+    return ReadRawField<internal::Address>(heap_object_ptr, offset);
+#endif
+  }
+
+#ifdef V8_COMPRESS_POINTERS
+  static constexpr size_t kPtrComprHeapReservationSize = size_t{1} << 32;
+  static constexpr size_t kPtrComprIsolateRootBias =
+      kPtrComprHeapReservationSize / 2;
+  static constexpr size_t kPtrComprIsolateRootAlignment = size_t{1} << 32;
+
+  V8_INLINE static internal::Address GetRootFromOnHeapAddress(
+      internal::Address addr) {
+    return (addr + kPtrComprIsolateRootBias) &
+           -static_cast<intptr_t>(kPtrComprIsolateRootAlignment);
+  }
+
+#else
+
   template <typename T>
   V8_INLINE static T ReadEmbedderData(const v8::Context* context, int index) {
     typedef internal::Address A;
     typedef internal::Internals I;
     A ctx = *reinterpret_cast<const A*>(context);
-    A embedder_data = I::ReadField<A>(ctx, I::kNativeContextEmbedderDataOffset);
+    A embedder_data =
+        I::ReadTaggedPointerField(ctx, I::kNativeContextEmbedderDataOffset);
     int value_offset =
         I::kEmbedderDataArrayHeaderSize + (I::kEmbedderDataSlotSize * index);
-    return I::ReadField<T>(embedder_data, value_offset);
+    return I::ReadRawField<T>(embedder_data, value_offset);
   }
-#endif
+#endif  // V8_COMPRESS_POINTERS
 };
 
 // Only perform cast check for types derived from v8::Data since

include/v8.h

@@ -695,7 +695,7 @@ template <class T, class M> class Persistent : public PersistentBase<T> {
   V8_INLINE Persistent(const Persistent<S, M2>& that) : PersistentBase<T>(0) {
     Copy(that);
   }
-  V8_INLINE Persistent& operator=(const Persistent& that) { // NOLINT
+  V8_INLINE Persistent& operator=(const Persistent& that) {
     Copy(that);
     return *this;
   }
@@ -779,7 +779,7 @@ class Global : public PersistentBase<T> {
   /**
    * Move constructor.
    */
-  V8_INLINE Global(Global&& other) : PersistentBase<T>(other.val_) {  // NOLINT
+  V8_INLINE Global(Global&& other) : PersistentBase<T>(other.val_) {
     other.val_ = nullptr;
   }
   V8_INLINE ~Global() { this->Reset(); }
@@ -9934,7 +9934,7 @@ Local<Value> Object::GetInternalField(int index) {
       instance_type == I::kJSSpecialApiObjectType) {
     int offset = I::kJSObjectHeaderSizeForEmbedderFields +
                  (I::kEmbedderDataSlotSize * index);
-    A value = I::ReadField<A>(obj, offset);
+    A value = I::ReadTaggedAnyField(obj, offset);
     A* result = HandleScope::CreateHandle(
         reinterpret_cast<internal::NeverReadOnlySpaceObject*>(obj), value);
     return Local<Value>(reinterpret_cast<Value*>(result));
@@ -9957,7 +9957,7 @@ void* Object::GetAlignedPointerFromInternalField(int index) {
                 instance_type == I::kJSSpecialApiObjectType)) {
     int offset = I::kJSObjectHeaderSizeForEmbedderFields +
                  (I::kEmbedderDataSlotSize * index);
-    return I::ReadField<void*>(obj, offset);
+    return I::ReadRawField<void*>(obj, offset);
   }
 #endif
   return SlowGetAlignedPointerFromInternalField(index);
@@ -9987,7 +9987,7 @@ String::ExternalStringResource* String::GetExternalStringResource() const {
 
   ExternalStringResource* result;
   if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
-    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    void* value = I::ReadRawField<void*>(obj, I::kStringResourceOffset);
     result = reinterpret_cast<String::ExternalStringResource*>(value);
   } else {
     result = GetExternalStringResourceSlow();
@@ -10009,7 +10009,7 @@ String::ExternalStringResourceBase* String::GetExternalStringResourceBase(
   ExternalStringResourceBase* resource;
   if (type == I::kExternalOneByteRepresentationTag ||
       type == I::kExternalTwoByteRepresentationTag) {
-    void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
+    void* value = I::ReadRawField<void*>(obj, I::kStringResourceOffset);
     resource = static_cast<ExternalStringResourceBase*>(value);
   } else {
     resource = GetExternalStringResourceBaseSlow(encoding_out);

src/api.cc

@@ -5560,7 +5560,7 @@ String::ExternalStringResource* String::GetExternalStringResourceSlow() const {
   }
 
   if (i::StringShape(str).IsExternalTwoByte()) {
-    void* value = I::ReadField<void*>(str.ptr(), I::kStringResourceOffset);
+    void* value = I::ReadRawField<void*>(str.ptr(), I::kStringResourceOffset);
     return reinterpret_cast<String::ExternalStringResource*>(value);
   }
   return nullptr;
@@ -5582,7 +5582,7 @@ String::ExternalStringResourceBase* String::GetExternalStringResourceBaseSlow(
   *encoding_out = static_cast<Encoding>(type & I::kStringEncodingMask);
   if (i::StringShape(str).IsExternalOneByte() ||
       i::StringShape(str).IsExternalTwoByte()) {
-    void* value = I::ReadField<void*>(string, I::kStringResourceOffset);
+    void* value = I::ReadRawField<void*>(string, I::kStringResourceOffset);
     resource = static_cast<ExternalStringResourceBase*>(value);
   }
   return resource;
@@ -5613,9 +5613,15 @@ Local<Value> Symbol::Name() const {
     // objects are immovable we can use the Handle(Address*) constructor with
     // the address of the name field in the Symbol object without needing an
     // isolate.
+#ifdef V8_COMPRESS_POINTERS
+    // Compressed fields can't serve as handle locations.
+    // TODO(ishell): get Isolate as a parameter.
+    isolate = i::Isolate::Current();
+#else
     i::Handle<i::HeapObject> ro_name(reinterpret_cast<i::Address*>(
         sym->GetFieldAddress(i::Symbol::kNameOffset)));
     return Utils::ToLocal(ro_name);
+#endif
   }
 
   i::Handle<i::Object> name(sym->name(), isolate);

src/roots-inl.h

@@ -33,9 +33,9 @@ V8_INLINE RootIndex operator++(RootIndex& index) {
 
 bool RootsTable::IsRootHandleLocation(Address* handle_location,
                                       RootIndex* index) const {
-  ObjectSlot location(handle_location);
-  ObjectSlot first_root(&roots_[0]);
-  ObjectSlot last_root(&roots_[kEntriesCount]);
+  FullObjectSlot location(handle_location);
+  FullObjectSlot first_root(&roots_[0]);
+  FullObjectSlot last_root(&roots_[kEntriesCount]);
   if (location >= last_root) return false;
   if (location < first_root) return false;
   *index = static_cast<RootIndex>(location - first_root);