Have a working browser

[tomaka]

That's obviously the biggest milestone.
Compiling an existing browser engine to WASI and running.

[tomaka]

I've started a branch of servo that envisions to compile for wasi: https://github.com/tomaka/servo/tree/wasi-hack

Unfixed problems:

• Wasi doesn't support sockets, and as such it's not possible to properly implement support in mio/tokio. Support for sockets will eventually happen.
• All the OpenGL stack needs to be implemented, and it's unlikely for Wasi to ever support a graphics stack. Fortunately, Servo is organized as a library, and all we need to provide to the Servo library is OpenGL function pointers.
• Servo needs a way to later query how much a pointer returned by malloc actually occupies memory: malloc_size_of. To implement this, they force usage of jemalloc on Linux, and use an API that does that on Windows.
• Freetype (the C library) uses setjmp/longjmp. To make it compile, I've replaced them with dummy implementations.
• Harfbuzz needs mutexes but there's no <pthread.h> in the Wasi SDK. Can be replaced with stubs, since Wasm is always single threaded at the moment.

Note that this concerns only compiling Servo. Actually running it will probably uncover a lot more issues, for example Servo trying to spawn threads or accessing files.

[tomaka]

The solution to having to support OpenGL could be to port the software renderer of mesa3d (used by osmesa).

[tomaka]

cc #701

[PaperPrototype]

It will be cool to pass WebASM from websites directly to run on the OS WASI :P