Make v8 api forwards compatible with v8 6.7

[nornagon]

Cribbed from https://github.com/nodejs/node/commit/2a3f8c3a83e3820d3c601bdf02eda8db462027aa

[alexeykuzmin]

Why do we need this?

[nornagon]

Building 3rd-party modules against the version of node we depend on (v10.2.0) results in modules that are incompatible with the version of v8 in chrome 66 (v6.6.346.32), because node v10.2.0 includes this patch in its vendored v8.

In particular, the thing i ran into is that node v10.2.0 has this signature for v8::FunctionTemplate::New:

Local<FunctionTemplate> FunctionTemplate::New(
    Isolate* isolate, FunctionCallback callback, v8::Local<Value> data,
    v8::Local<Signature> signature, int length, ConstructorBehavior behavior,
    SideEffectType side_effect_type);

but the function signature for v8::FunctionTemplate::New in chromium's version of v8 (v6.6.346.32) is:

Local<FunctionTemplate> FunctionTemplate::New(
    Isolate* isolate, FunctionCallback callback, v8::Local<Value> data,
    v8::Local<Signature> signature, int length, ConstructorBehavior behavior);

So a module built against node v10.2.0's v8 headers won't work with our v8.

[alexeykuzmin]

So a module built against node v10.2.0's v8 headers won't work with our v8.

Is it expected to do so? @zcbenz ,can you help us to understand how the thing should work here?

[nornagon]

ah, i see that the create-node-headers.py script in e/e overrides nodejs's v8 headers with the headers from chrome. I should probably figure out a way to do that in the gn build.

[MarshallOfSound]

In the past we've tried to make this work (building native modules for electron by building them on the right node version) but afaik it has sometimes worked on *nix but it has never worked on windows.

We have electron-rebuild and friends to make getting around this problem easy

[nornagon]

electron-rebuild doesn't work for development tho (i.e. developing on an unreleased electron)

[MarshallOfSound]

This is correct but there are helper scripts in the electron repo to rebuild native modules with electron generated headers.

[nornagon]

Closed, going to instead figure out a nice way to build our test modules against the proper v8 headers in the GN build.