Is there a list of name in global module?

Unfortunately the Emscripten ABI isn't stable. The best source for that information is the Emscripten source code for the various versions.

"global", "NaN" and "Infinity" are core concept. Could you use const variable and aggregate them in single place?

A naive question
Where is makeGlobalWavm instantiated?

It is in the wasm/wavm/wavm.cc file. It is encapsulated in that file. The idea is to make the details of the individual VM implementations private. I choose that because wavm/wavm.h is included in wasm/wasm.cc but not wasm/wasm.h to prevent circularizing the includes. I am planning on moving class WavmVm into a new file and reorganizing the includes here which would enable moving this declaration into the wavm/ directory, after clearing the current PR backlog.

Another naive question
Where can I find a inherited Global ?

in wavm/wavm.cc. That is the private VM specific implementation of the Global class.

Thanks! I didn't find it because github doesn't render large diff.

Thanks! I didn't find it because github doesn't render large diff.

virtual T get() override;

done

virtual void set(const T& t) override;

BTW: is multiple line comment supported? I didn't find an approach to mark multiple lines that need attention.

Feel free to ignore: This green area is quite isolated from the existing logic. It doesn't use any stack variable so it's reasonable to name this piece some other day.

Is this necessary? SFINAE

Yes, but it will fail to compile if is actually used because it doesn't return anything.

This implementation remind me that the return type should be std::decay_t to avoid get reference (e.g, T = int32_t&)

discussed offline. This is only used for templates explicitly instantiated in this file, so there is no chance of accidental &.

Why are you doing this? You may always write as below. There is no penalty and it is exception safe.

auto g_ptr = std::make_unique<WavmGlobal<T>>(...);
wavm->intrinsicGlobals_[...] = g_ptr.get();
return g_ptr;

It is a bit more complicated because the return type is std::unique_ptr<Global>> which the compiler will not auto-coerce from 'g'. Instead I have to do a std::static_pointer_cast<> and this works around that by using the automatic std::unique_ptr constructor coercion which does upcast "correctly" (IMO std::unique_ptr should do that was well, maybe in a later version of C++).

I'll change it.

My bad. You are right. The problem only happens with shared_ptr. Done.

cool