[wasm] Make WireBytesStorage keep wire bytes alive

The purpose of the {WireBytesStorage} (typically held in a shared_ptr
itself) is to keep the actual wire bytes alive. Thus implement it this
way for the {NativeModuleWireBytesStorage}.

R=mstarzinger@chromium.org

Bug: v8:8689
Change-Id: I8f171b4fa8b80b517badb1b1d3228503a32830dd
Reviewed-on: https://chromium-review.googlesource.com/c/1421362
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58966}

src/wasm/wasm-code-manager.cc

@@ -803,24 +803,27 @@ Vector<byte> NativeModule::AllocateForCode(size_t size) {
 namespace {
 class NativeModuleWireBytesStorage final : public WireBytesStorage {
  public:
-  explicit NativeModuleWireBytesStorage(NativeModule* native_module)
-      : native_module_(native_module) {}
+  explicit NativeModuleWireBytesStorage(
+      std::shared_ptr<OwnedVector<const uint8_t>> wire_bytes)
+      : wire_bytes_(std::move(wire_bytes)) {}
 
   Vector<const uint8_t> GetCode(WireBytesRef ref) const final {
-    return native_module_->wire_bytes().SubVector(ref.offset(),
-                                                  ref.end_offset());
+    return wire_bytes_->as_vector().SubVector(ref.offset(), ref.end_offset());
   }
 
  private:
-  NativeModule* const native_module_;
+  const std::shared_ptr<OwnedVector<const uint8_t>> wire_bytes_;
 };
 }  // namespace
 
-void NativeModule::SetWireBytes(OwnedVector<const byte> wire_bytes) {
-  wire_bytes_ = std::move(wire_bytes);
-  if (!wire_bytes.is_empty()) {
+void NativeModule::SetWireBytes(OwnedVector<const uint8_t> wire_bytes) {
+  auto shared_wire_bytes =
+      std::make_shared<OwnedVector<const uint8_t>>(std::move(wire_bytes));
+  wire_bytes_ = shared_wire_bytes;
+  if (!shared_wire_bytes->is_empty()) {
     compilation_state_->SetWireBytesStorage(
-        std::make_shared<NativeModuleWireBytesStorage>(this));
+        std::make_shared<NativeModuleWireBytesStorage>(
+            std::move(shared_wire_bytes)));
   }
 }
 

src/wasm/wasm-code-manager.h

@@ -339,11 +339,11 @@ class V8_EXPORT_PRIVATE NativeModule final {
   UseTrapHandler use_trap_handler() const { return use_trap_handler_; }
   void set_lazy_compile_frozen(bool frozen) { lazy_compile_frozen_ = frozen; }
   bool lazy_compile_frozen() const { return lazy_compile_frozen_; }
-  Vector<const byte> wire_bytes() const { return wire_bytes_.as_vector(); }
+  Vector<const uint8_t> wire_bytes() const { return wire_bytes_->as_vector(); }
   const WasmModule* module() const { return module_.get(); }
   size_t committed_code_space() const { return committed_code_space_.load(); }
 
-  void SetWireBytes(OwnedVector<const byte> wire_bytes);
+  void SetWireBytes(OwnedVector<const uint8_t> wire_bytes);
 
   WasmCode* Lookup(Address) const;
 
@@ -427,7 +427,9 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // AsyncCompileJob).
   std::shared_ptr<const WasmModule> module_;
 
-  OwnedVector<const byte> wire_bytes_;
+  // Wire bytes, held in a shared_ptr so they can be kept alive by the
+  // {WireBytesStorage}, held by background compile tasks.
+  std::shared_ptr<OwnedVector<const uint8_t>> wire_bytes_;
 
   WasmCode* runtime_stub_table_[WasmCode::kRuntimeStubCount] = {nullptr};