WASM: auto-export library functions, make elements support optional

[jgriffiths]

No description provided.

[shesek]

It seems like the wasm bundle I'm building for esplora grew from 79kb to 133kb, could this be due --enable-export-all? Why was it added?

Edit: Nope, it is not that, I tried without --enable-export-all and got the same size. Maybe libwally just got bigger since lawrence's original webassembly branch?

[jgriffiths]

Edit: Nope, it is not that, I tried without --enable-export-all and got the same size. Maybe libwally just got bigger since lawrence's original webassembly branch?

--enable-export-all just disables symbol visibility. I think the size is controlled by which functions you choose to export. If you pass your own list of just the functions you need, the optimiser will eliminate all the dead code leaving you with a minimal wasm file.

edit: I see you are passing your own list of functions, I can't explain this but its possible the code has grown since Lawrence did the first wasm port I think. You could try earlier wally versions if you want to find out when it grew...