Unoptimized WASM output

[guest271314]

Here's the source code I used

import { readSync } from "node:fs";
const buffer = new Uint8Array(32);
readSync(0, buffer,  0, buffer.length );
process.stdout.write(buffer);

Here's the compilation command

SCRIPTC_NO_CACHE=1 SCRIPTC_CC=zigcc SCRIPTC_TARGET=wasm32-wasi bun x scriptc build hello.ts --keep-c --optimization release -o hello.wasm >/dev/null

Now, that spits out a 1.8 MiB WASM binary.

However, if I then do wasm2wat then wat2wasm starting with that same hello.wasm file, I get a 565.3 KiB WAT file and then a 53.1 KiB WASM file.

wabt-1.0.41/bin/wasm2wat hello.wasm -o hello.wat
wabt-1.0.41/bin/wat2wasm hello.wat -o hello1.wasm

Using wasm-opt directly on the hello.wasm file I get down to 46.9 KiB

wasm-opt hello.wasm -Os --strip-debug --vacuum -o hello2.wasm

Two questions arise for me:

1. How to determine if QuickJS NG is embedded in the resulting WASM binary?
2. How to optimize the WASM binary output so that is roughly matches the output of wasm-opt?

[guest271314]

@ctate Actually, there are other problems. I can create separate issues for those if you want, or concentrate them here.

Basically, scriptc doesn't work for basic stuff like writing an ArrayBuffer to stdout. Discord link in WebAssembly https://discord.com/channels/453584038356058112/1546664657299837008/1547589474077249677. Yes, @tr

These https://github.com/loopdive/js2/tree/main/examples/native-messaging#five-hosts-one-wire-protocol--a-comparison, perhaps save for [nm_js2wasm_wasi_p1.ts](https://github.com/loopdive/js2/blob/main/examples/native-messaging/nm_js2wasm_wasi_p1.ts), should all be compilable by scriptc and executable by a WASM engine.

scriptc currently doesn't handle these, e.g.,

SCRIPTC_NO_CACHE=1 SCRIPTC_CC=zigcc SCRIPTC_TARGET=wasm32-wasi bun x scriptc build nm_js2wasm_node_fs.ts --keep-c --optimization release -o nm_js2wasm_scriptc.wasm >/dev/null
/media/user/x/d8/nm_js2wasm_node_fs.ts:66:27 - error SC0001: Cannot find module './nm_js2wasm_sync_framing.ts' or its corresponding type declarations.

  65 | import { readSync, writeSync } from "node:fs";
  66 | import { runNmHost } from "./nm_js2wasm_sync_framing.ts";
     |                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  67 | 

/media/user/x/d8/nm_js2wasm_node_fs.ts:72:10 - error SC0001: Expected 4-5 arguments, but got 3.

  71 | function nodeFsRead(buf: Uint8Array): number | null {
  72 |   return readSync(0, buf, { offset: 0, length: buf.length });
     |          ^~~~~~~~
  73 | }

/media/user/x/d8/nm_js2wasm_node_fs.ts:79:28 - error SC0001: Argument of type 'Uint8Array<ArrayBufferLike>' is not assignable to parameter of type 'string'.

  78 |   while (n < buf.length) {
  79 |     const w = writeSync(1, buf, n);
     |                            ^~~
  80 |     if (w <= 0) return; // error; nothing more we can do on this frame

/media/user/x/d8/nm_js2wasm_node_fs.ts:144:28 - error SC0001: Argument of type 'Uint8Array<ArrayBuffer>' is not assignable to parameter of type 'string'.

  143 |   while (m < bytes.length) {
  144 |     const w = writeSync(2, bytes, m);
      |                            ^~~~~
  145 |     if (w <= 0) return;

4 errors.

@ttraenkler mentioned he contacted you re collaboration. That would probably be a good idea. See all of the stuff we went over here loopdive/js2#389.