no_mangle seems to only export functions, not the BUFFER

[pfedan]

Hi,
when running your example (dfe8f8a) on Windows (yes, I compiled binaryen and wabt with VS2019), I get the following message in the browser console:

Uncaught (in promise) TypeError: Cannot read property 'value' of undefined
at init ((index):14)

Printing the wasm instance shows:

It seems to me, that the #[no_mangle] directive does not export BUFFER as I would expect...

[pfedan]

I was able to circumvent the problem using

#[no_mangle]
pub unsafe extern fn addr() -> &'static [u32; WIDTH * HEIGHT] {
    &BUFFER
}

and calling it from JS via:
const buffer_address = instance.exports.addr();

Nevertheless, I'd like to understand, why I can't seem to be able to access an exported BUFFER directly.

[egemengol]

I have faced the same problem with ubuntu and chrome.
wasm-objdump gives

$ wasm-objdump -d www/bare_metal_wasm.wasm 

bare_metal_wasm.wasm:   file format wasm 0x1

Code Disassembly:

00005a func[0] <go>:
 00005b: 02 7f                      | local[0..1] type=i32
 00005d: 03 40                      | loop
 00005f: 20 00                      |   local.get 0
 000061: 41 01                      |   i32.const 1
 000063: 6a                         |   i32.add
 000064: 21 00                      |   local.set 0
 000066: 41 d8 04                   |   i32.const 600
 000069: 21 01                      |   local.set 1
 00006b: 03 40                      |   loop
 00006d: 20 01                      |     local.get 1
 00006f: 41 7f                      |     i32.const 4294967295
 000071: 6a                         |     i32.add
 000072: 22 01                      |     local.tee 1
 000074: 0d 00                      |     br_if 0
 000076: 0b                         |   end
 000077: 20 00                      |   local.get 0
 000079: 41 d8 04                   |   i32.const 600
 00007c: 47                         |   i32.ne
 00007d: 0d 00                      |   br_if 0
 00007f: 0b                         | end
 000080: 0b                         | end

in which I cannot see the buffer, I might be wrong.

I was able to circumvent the problem using

Thanks for the hack

[tdejager]

Had the same problem on Ubuntu 18.04, with Firefox. Using rust 1.41. Thanks for the hack :)