[zone] Final cleanup of zone allocations

... by migrating old-style code
  MyObject* obj = new (zone) MyObject(...)

to the new style
  MyObject* obj = zone->New<MyObject>(...)

... and prohibiting accidental use of the old-style.

Bug: v8:10689
Change-Id: Id75774ac12e3d0f95cb3a538066dffbf7815e438
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2300490
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68905}

src/compiler/js-operator.cc

@@ -1116,7 +1116,7 @@ const Operator* JSOperatorBuilder::LoadModule(int32_t cell_index) {
 }
 
 const Operator* JSOperatorBuilder::GetImportMeta() {
-  return new (zone()) Operator(    // --
+  return zone()->New<Operator>(    // --
       IrOpcode::kJSGetImportMeta,  // opcode
       Operator::kNoProperties,     // flags
       "JSGetImportMeta",           // name

src/compiler/simplified-operator.cc

@@ -1743,7 +1743,7 @@ const Operator* SimplifiedOperatorBuilder::NewSmiOrObjectElements(
 
 const Operator* SimplifiedOperatorBuilder::NewArgumentsElements(
     CreateArgumentsType type, int formal_parameter_count) {
-  return new (zone()) Operator1<NewArgumentsElementsParameters>(  // --
+  return zone()->New<Operator1<NewArgumentsElementsParameters>>(  // --
       IrOpcode::kNewArgumentsElements,                            // opcode
       Operator::kEliminatable,                                    // flags
       "NewArgumentsElements",                                     // name
@@ -1920,7 +1920,7 @@ const Operator* SimplifiedOperatorBuilder::FastApiCall(
        FastApiCallNode::kFastTargetInputCount) +        // fast call
       static_cast<int>(descriptor->ParameterCount()) +  // slow call
       FastApiCallNode::kEffectAndControlInputCount;
-  return new (zone_) Operator1<FastApiCallParameters>(
+  return zone()->New<Operator1<FastApiCallParameters>>(
       IrOpcode::kFastApiCall, Operator::kNoThrow, "FastApiCall",
       value_input_count, 1, 1, 1, 1, 0,
       FastApiCallParameters(signature, feedback, descriptor));

src/zone/zone.h

@@ -39,9 +39,6 @@ class V8_EXPORT_PRIVATE Zone final {
   Zone(AccountingAllocator* allocator, const char* name);
   ~Zone();
 
-  // TODO(v8:10689): Remove once all allocation sites are migrated.
-  void* New(size_t size) { return Allocate<void>(size); }
-
   // Allocate 'size' bytes of uninitialized memory in the Zone; expands the Zone
   // by allocating new segments of memory on demand using AccountingAllocator
   // (see AccountingAllocator::AllocateSegment()).
@@ -178,10 +175,16 @@ class V8_EXPORT_PRIVATE Zone final {
 // allocated in the Zone. Use it as a base class; see ast.h.
 class ZoneObject {
  public:
-  // Allocate a new ZoneObject of 'size' bytes in the Zone.
-  void* operator new(size_t size, Zone* zone) { return zone->New(size); }
+  // The accidential old-style pattern
+  //    new (zone) SomeObject(...)
+  // now produces compilation error. The proper way of allocating objects in
+  // Zones looks like this:
+  //    zone->New<SomeObject>(...)
+  void* operator new(size_t, Zone*) = delete;  // See explanation above.
   // Allow non-allocating placement new.
-  void* operator new(size_t size, void* ptr) { return ptr; }
+  void* operator new(size_t size, void* ptr) {  // See explanation above.
+    return ptr;
+  }
 
   // Ideally, the delete operator should be private instead of
   // public, but unfortunately the compiler sometimes synthesizes
@@ -191,8 +194,9 @@ class ZoneObject {
 
   // ZoneObjects should never be deleted individually; use
   // Zone::DeleteAll() to delete all zone objects in one go.
+  // Note, that descructors will not be called.
   void operator delete(void*, size_t) { UNREACHABLE(); }
-  void operator delete(void* pointer, Zone* zone) { UNREACHABLE(); }
+  void operator delete(void* pointer, Zone* zone) = delete;
 };
 
 // The ZoneAllocationPolicy is used to specialize generic data
@@ -221,17 +225,12 @@ class ZoneAllocationPolicy {
 }  // namespace internal
 }  // namespace v8
 
-// The accidential pattern
-//    new (zone) SomeObject()
-// where SomeObject does not inherit from ZoneObject leads to nasty crashes.
-// This triggers a compile-time error instead.
-template <class T, typename = typename std::enable_if<std::is_convertible<
-                       T, const v8::internal::Zone*>::value>::type>
-void* operator new(size_t size, T zone) {
-  static_assert(false && sizeof(T),
-                "Placement new with a zone is only permitted for classes "
-                "inheriting from ZoneObject");
-  UNREACHABLE();
-}
+// The accidential old-style pattern
+//    new (zone) SomeObject(...)
+// now produces compilation error. The proper way of allocating objects in
+// Zones looks like this:
+//    zone->New<SomeObject>(...)
+void* operator new(size_t, v8::internal::Zone*) = delete;   // See explanation.
+void operator delete(void*, v8::internal::Zone*) = delete;  // See explanation.
 
 #endif  // V8_ZONE_ZONE_H_

test/cctest/wasm/wasm-run-utils.cc

@@ -498,10 +498,13 @@ Handle<Code> WasmFunctionWrapper::GetWrapperCode() {
   return code;
 }
 
+// This struct is just a type tag for Zone::NewArray<T>(size_t) call.
+struct WasmFunctionCompilerBuffer {};
+
 void WasmFunctionCompiler::Build(const byte* start, const byte* end) {
   size_t locals_size = local_decls.Size();
   size_t total_size = end - start + locals_size + 1;
-  byte* buffer = zone()->NewArray<byte>(total_size);
+  byte* buffer = zone()->NewArray<byte, WasmFunctionCompilerBuffer>(total_size);
   // Prepend the local decls to the code.
   local_decls.Emit(buffer);
   // Emit the code.

test/unittests/zone/zone-unittest.cc

@@ -10,12 +10,15 @@
 namespace v8 {
 namespace internal {
 
+// This struct is just a type tag for Zone::Allocate<T>(size_t) call.
+struct ZoneTest {};
+
 TEST(Zone, 8ByteAlignment) {
   AccountingAllocator allocator;
   Zone zone(&allocator, ZONE_NAME);
 
   for (size_t i = 0; i < 16; ++i) {
-    ASSERT_EQ(reinterpret_cast<intptr_t>(zone.New(i)) % 8, 0);
+    ASSERT_EQ(reinterpret_cast<intptr_t>(zone.Allocate<ZoneTest>(i)) % 8, 0);
   }
 }