Fatal error: Interceptor silently changed store target

[Danny Dorfman]

Hello there,

I just updated my V8 to the latest 5.2 patch level (5.2.361.54), and now I'm getting this error:

#

# Fatal error in v8::NamedPropertySetterCallback

# Interceptor silently changed store target.

#

What exactly does it mean? Please assist.

Regards,

Danny

[Danny Dorfman]

Here is a program that demonstrates this issue: (removing line #28 eliminates the problem)

  1 #include <iostream>

  2 #include <string.h>

  3 #include "v8/libplatform/libplatform.h"

  4 #include "v8/v8.h"

  5 

  6 class ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {

  7  public:

  8   virtual void* Allocate(size_t length) {

  9     void* data = AllocateUninitialized(length);

 10     return data == NULL ? data : memset(data, 0, length);

 11   }

 12   virtual void* AllocateUninitialized(size_t length) { return malloc(length); }

 13   virtual void Free(void* data, size_t) { free(data); }

 14 };

 15 

 16 void GetProperty(v8::Local<v8::String> property, const v8::PropertyCallbackInfo<v8::Value>& info)

 17 {

 18     v8::String::Utf8Value asciiprop(property);

 19     std::cout << "GETTER: property=" << *asciiprop << std::endl;

 20 }

 21 

 22 void SetProperty(v8::Local<v8::String> property, v8::Local<v8::Value> value, const v8::PropertyCallbackInfo<v8::Value>& info)

 23 {

 24     v8::Isolate *isolate = info.GetIsolate();

 25     v8::String::Utf8Value asciiproperty(property);

 26     v8::String::Utf8Value asciivalue(value);

 27     std::cout << "SETTER: property=" << *asciiproperty << ", value=" <<  *asciivalue << std::endl;

 28     std::cout << "SETTER: hash=" << info.This()->GetIdentityHash() << std::endl;

 29 }

 30 

 31 int main(int argc, char* argv[])

 32 {

 33   // Initialize V8.

 34   v8::V8::InitializeICU();

 35   v8::V8::InitializeExternalStartupData(argv[0]);

 36   v8::Platform* platform = v8::platform::CreateDefaultPlatform();

 37   v8::V8::InitializePlatform(platform);

 38   v8::V8::Initialize();

 39 

 40   // Create a new Isolate and make it the current one.

 41   ArrayBufferAllocator allocator;

 42   v8::Isolate::CreateParams create_params;

 43   create_params.array_buffer_allocator = &allocator;

 44   v8::Isolate* isolate = v8::Isolate::New(create_params);

 45   {

 46     v8::Isolate::Scope isolate_scope(isolate);

 47     v8::HandleScope handle_scope(isolate);

 48     v8::Local<v8::ObjectTemplate> objectTemplate = v8::ObjectTemplate::New();

 49     objectTemplate->SetNamedPropertyHandler(GetProperty,SetProperty);

 50     v8::Local<v8::Context> ctx = v8::Context::New(isolate);

 51     v8::Context::Scope context_scope(ctx);

52 

 53     // run tests

 54     v8::Local<v8::String> fooStr = v8::String::NewFromUtf8(isolate, "foo");

 55     v8::Local<v8::String> barStr = v8::String::NewFromUtf8(isolate, "bar");

 56     v8::Local<v8::Object> obj = objectTemplate->NewInstance();

 57     obj->Set(fooStr, barStr);

 58   }

 59 

 60   // Dispose the isolate and tear down V8.

 61   isolate->Dispose();

 62   v8::V8::Dispose();

 63   v8::V8::ShutdownPlatform();

 64   delete platform;

 65   return 0;

 66 }

[Ben Noordhuis]

I think you found a bug.

JSObject::GetOrCreateIdentityHash() computes the hash lazily and
caches it as a symbol property on the object but it looks up that
property with the OWN flag instead of OWN_SKIP_INTERCEPTOR. That
looks incorrect because it means it's going to call your interceptor
again.

There is a debug check that verifies it's a data property but it's
skipped in release builds. I'd file an issue if I were you.

[Danny Dorfman]

Hi Ben,

Thanks for backing up my suspicion. Bug was filed ... https://bugs.chromium.org/p/v8/issues/detail?id=5379

D.