Note: This code is currently WIP. There are a number of known issues.
depot_tools
Dawn uses the Chromium build system and dependency management so you need to install depot_tools and add it to the PATH.
First, the steps are similar to docs/building.md
, but instead of the Get the code
step, run:
# 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
Optionally, on Linux install X11-xcb support:
sudo apt-get install libx11-xcb-dev
If you don't have those supporting libraries, then you must use the -DDAWN_USE_X11=OFF
flag on Cmake.
Currently, the node bindings can only be built with CMake:
mkdir <build-output-path> cd <build-output-path> cmake <dawn-root-path> -GNinja -DDAWN_BUILD_NODE_BINDINGS=1 -DDAWN_ENABLE_PIC=1 -DDAWN_USE_X11=OFF ninja dawn.node
dawn.node
NodeJS module.npm install
from inside the CTS directory to install its dependencies./src/tools/run run-cts --dawn-node=<path-to-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/tools/run run-cts
with VK_ICD_FILENAMES=<swiftshader-cmake-build>/Linux/vk_swiftshader_icd.json
. For example:
VK_ICD_FILENAMES=<swiftshader-cmake-build>/Linux/vk_swiftshader_icd.json ./src/tools/run run-cts --dawn-node=<path-to-dawn.node> [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=<null|webgpu|d3d11|d3d12|metal|vulkan|opengl|opengles>
dlldir=<path>
- used to add an extra DLL search path on Windows, primarily to load the right d3dcompiler_47.dllenable-dawn-features=<features>
- enable Dawn toggles, e.g. dump_shaders
disable-dawn-features=<features>
- disable Dawn togglesFor 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:
./src/tools/run run-cts --verbose --dawn-node=/c/src/dawn/build/Debug/dawn.node --cts=/c/src/webgpu-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.
run-cts
expectations fileYou can write out an expectations file with the --output <path>
command line flag, and then compare this snapshot to a later run with --expect <path>
.
Dawn needs to be built with clang and the DAWN_EMIT_COVERAGE
CMake flag.
Optionally, the LLVM_SOURCE_DIR
CMake flag can also be specified to point the the ./llvm
directory of an LLVM checkout, which will build turbo-cov
and dramatically speed up the processing of coverage data.
Run ./src/tools/run run-cts
like before, but include the --coverage
flag. After running the tests, your browser will open with a coverage viewer.
Click a source file in the left hand panel, then click a green span in the file source to see the tests that exercised that code.
You can also highlight multiple lines to view all the tests that covered any of that highlighted source.
Open or create the .vscode/launch.json
file, and add:
{ "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');", "--", "placeholder-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 steptest-query
with the test query string. Example: webgpu:shader,execution,builtin,abs:*
It is possible to run the CTS with dawn-node directly similarly to Debugging TypeScript with VSCode:
cd <cts-root-dir> [path-to-node] \ # for example <dawn-root-dir>/third_party/node/<arch>/node -e "require('./src/common/tools/setup-ts-in-node.js');require('./src/common/runtime/cmdline.ts');" \ -- \ placeholder-arg \ --gpu-provider [path to dawn.node] \ [test-query]
This command is then possible to run in your debugger of choice.
new T
in JavaScript, where T
is an IDL interface type, should result in a TypeError “Illegal constructor”. discussionGPUDevice
currently maintains a list of “lost promises”. This should return the same promise. discussionsrc/
for dawn/node
, but outside for Dawn. discussionbinding::GPU
will require significant rework once Dawn implements the device / adapter creation path properly.