hermes is incompatible with numjs and cwise library

[paradite]

Problem

The hermes engine is incompatible with numjs, which uses cwise library for generate cache efficient map/reduce operations.

When using numjs, some functions are dynamically generated by the library based on the dimensions of arguments provided.

For example, for the unpack function here reproduced below:

var doUnpack = cwise({
  args: ['array', 'scalar', 'index'],
  body: function unpackCwise (arr, a, idx) {
    var v = a;
    var i;
    for (i = 0; i < idx.length - 1; ++i) {
      v = v[idx[i]];
    }
    v[idx[idx.length - 1]] = arr;
  }
});

When using jsc, the functions can be generated correctly:

However, using hermes, we got an error, presumably because the function has already been compiled to bytecode, and the generated function can't make use of it:

Sample error for search indexing:

ReferenceError: Property '_inline_9_bytecode' doesn't exist, js engine: hermes

Solution

Using jsc can be a walkaround but with hermes going to be default, I hope this issue can be addressed with hermes.

Some ideas:

• Can hermes provides some ability to opt out / exclude bytecode for certain functions?
• Is there any way I can modify the numjs and cwise lib to make it compatible with the way hermes work now?

Any help on this issue would be appreciated.

Additional Context

Here's the relevant code for compiling and generating dynamic function in cwise-compiler:

https://github.com/scijs/cwise-compiler/blob/b65933f021302e15c6d4624353bb4b69168cd543/lib/compile.js#L116-L199

[tmikov]

If you add the directive "show source" to a function, Hermes will preserve its source code. For example:

function foo() {
  "show source";
  return 1 + 1;
}
print(foo.toString());

[paradite]

Thank you for the help @tmikov, let me try it out.

[paradite]

It seems to work, but now I am running into https://github.com/facebook/hermes/issues/612

Update: I am able to walk around #612 by triggering a hot-reload of the file that contains "show source";.

Feel free to close this issue.