# Dawn bindings for NodeJS Note: This code is currently WIP. There are a number of [known issues](#known-issues). ## Building ## System requirements - [CMake 3.10](https://cmake.org/download/) or greater - [Go 1.13](https://golang.org/dl/) or greater ## Install `depot_tools` Dawn uses the Chromium build system and dependency management so you need to [install depot_tools] and add it to the PATH. [install depot_tools]: http://commondatastorage.googleapis.com/chrome-infra-docs/flat/depot_tools/docs/html/depot_tools_tutorial.html#_setting_up ### Fetch dependencies First, the steps are similar to [`doc/building.md`](../../docs/building.md), but instead of the `Get the code` step, run: ```sh # Clone the repo as "dawn" git clone https://dawn.googlesource.com/dawn dawn && cd dawn # Bootstrap the NodeJS binding gclient configuration cp scripts/standalone-with-node.gclient .gclient # Fetch external dependencies and toolchains with gclient gclient sync ``` ### Build Currently, the node bindings can only be built with CMake: ```sh mkdir cd cmake -GNinja -DDAWN_BUILD_NODE_BINDINGS=1 -DDAWN_ENABLE_PIC=1 ninja dawn.node ``` ### Running WebGPU CTS 1. [Build](#build) the `dawn.node` NodeJS module. 2. Checkout the [WebGPU CTS repo](https://github.com/gpuweb/cts) - Run `npm install` from inside the CTS directory to install its dependencies ```sh ./src/dawn_node/tools/run-cts --cts= --dawn-node= [WebGPU CTS query] ``` If this fails with the error message `TypeError: expander is not a function or its return value is not iterable`, try appending `--build=false` to the start of the `run-cts` command line flags. To test against SwiftShader instead of the default Vulkan device, prefix `./src/dawn_node/tools/run-cts` with `VK_ICD_FILENAMES=/Linux/vk_swiftshader_icd.json` and append `--flag=dawn-backend=vulkan` to the start of run-cts command line flags. For example: ```sh VK_ICD_FILENAMES=/Linux/vk_swiftshader_icd.json ./src/dawn_node/tools/run-cts --cts= --dawn-node= --flag=dawn-backend=vulkan [WebGPU CTS query] ``` The `--flag` parameter must be passed in multiple times, once for each flag begin set. Here are some common arguments: * `dawn-backend=` * `dlldir=` - used to add an extra DLL search path on Windows, primarily to load the right d3dcompiler_47.dll * `enable-dawn-features=` - enable [Dawn toggles](https://dawn.googlesource.com/dawn/+/refs/heads/main/src/dawn_native/Toggles.cpp), e.g. `dump_shaders` * `disable-dawn-features=` - disable [Dawn toggles](https://dawn.googlesource.com/dawn/+/refs/heads/main/src/dawn_native/Toggles.cpp) For example, on Windows, to use the d3dcompiler_47.dll from a Chromium checkout, and to dump shader output, we could run the following using Git Bash: ```sh ./src/dawn_node/tools/run-cts --verbose --dawn-node=/c/src/dawn/build/Debug/dawn.node --cts=/c/src/gpuweb-cts --flag=dlldir="C:\src\chromium\src\out\Release" --flag=enable-dawn-features=dump_shaders 'webgpu:shader,execution,builtin,abs:integer_builtin_functions,abs_unsigned:storageClass="storage";storageMode="read_write";containerType="vector";isAtomic=false;baseType="u32";type="vec2%3Cu32%3E"' ``` Note that we pass `--verbose` above so that all test output, including the dumped shader, is written to stdout. ## Debugging TypeScript with VSCode Open or create the `.vscode/launch.json` file, and add: ```json { "version": "0.2.0", "configurations": [ { "name": "Debug with node", "type": "node", "request": "launch", "outFiles": [ "./**/*.js" ], "args": [ "-e", "require('./src/common/tools/setup-ts-in-node.js');require('./src/common/runtime/cmdline.ts');", "--", "dummy-arg", "--gpu-provider", "[path-to-dawn.node]", // REPLACE: [path-to-dawn.node] "[test-query]", // REPLACE: [test-query] ], "cwd": "[cts-root]" // REPLACE: [cts-root] } ] } ``` Replacing: - `[cts-root]` with the path to the CTS root directory. If you are editing the `.vscode/launch.json` from within the CTS workspace, then you may use `${workspaceFolder}`. - `[path-to-dawn.node]` this the path to the `dawn.node` module built by the [build step](#Build) - `test-query` with the test query string. Example: `webgpu:shader,execution,builtin,abs:*` ## Known issues - Many WebGPU CTS tests are currently known to fail - Dawn uses special token values for some parameters / fields. These are currently passed straight through to dawn from the JavaScript. discussions: [1](https://dawn-review.googlesource.com/c/dawn/+/64907/5/src/dawn_node/binding/Converter.cpp#167), [2](https://dawn-review.googlesource.com/c/dawn/+/64907/5/src/dawn_node/binding/Converter.cpp#928), [3](https://dawn-review.googlesource.com/c/dawn/+/64909/4/src/dawn_node/binding/GPUTexture.cpp#42) - Backend validation is currently always set to 'full' to aid in debugging. This can be extremely slow. [discussion](https://dawn-review.googlesource.com/c/dawn/+/64916/4/src/dawn_node/binding/GPU.cpp#25) - Attempting to call `new T` in JavaScript, where `T` is an IDL interface type, should result in a TypeError "Illegal constructor". [discussion](https://dawn-review.googlesource.com/c/dawn/+/64902/9/src/dawn_node/interop/WebGPU.cpp.tmpl#293) - `GPUDevice` currently maintains a list of "lost promises". This should return the same promise. [discussion](https://dawn-review.googlesource.com/c/dawn/+/64906/6/src/dawn_node/binding/GPUDevice.h#107) ## Remaining work - Investigate CTS failures that are not expected to fail. - Generated includes live in `src/` for `dawn_node`, but outside for Dawn. [discussion](https://dawn-review.googlesource.com/c/dawn/+/64903/9/src/dawn_node/interop/CMakeLists.txt#56) - Hook up to presubmit bots (CQ / Kokoro) - `binding::GPU` will require significant rework [once Dawn implements the device / adapter creation path properly](https://dawn-review.googlesource.com/c/dawn/+/64916/4/src/dawn_node/binding/GPU.cpp).