This folder builds an autonomous WASM preprocessor for Node/LSP. It does not depend on web/ artifacts.

• out/mcpp.wasm
• out/mcpp_node.js (stable Node wrapper API)
• out/mcpp_core.js (Emscripten runtime glue)

From repository root:

make -C tools/mcpp-wasm

The build uses third_party/mcpp sources and compiles a dedicated bridge with Emscripten. No system mcpp executable is required.

const mcpp = require("./out/mcpp_node.js");
const result = mcpp.preprocess(source, { file: "/path/file.pts" });
// result = { code, mapping: { preToOrigLine, origToPreLine } }

The VSCode language server loads src/frontend.js, which loads this wrapper at:

• tools/mcpp-wasm/out/mcpp_node.js

Before packaging/testing the VSCode extension, build this artifact:

npm --prefix tools/vscode/protoscript2 run build:mcpp-wasm

Current test script already does this automatically.