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dawn / dawn / 221ae88b5e952ea35312161caf2c33d66a2cfff7
commit221ae88b5e952ea35312161caf2c33d66a2cfff7[log] [tgz]
authorDavid Benjamin <davidben@google.com>Tue May 21 13:17:38 2024 +0000
committerDawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com>Tue May 21 13:17:38 2024 +0000
tree272c35e2c2b6828e251bd4910407024736c4cf67
parent209717796747895be7a1d0454e850aeebed94a8f [diff]
Don't memcpy zero bytes in generated WireCmd.cpp

Due to a C language bug, memcpy is undefined on empty inputs when the
pointers are NULL. See https://davidben.net/2024/01/15/empty-slices.html
for details. This code triggers UBSan bugs like the following:

https://luci-milo.appspot.com/ui/inv/build-8749056521619502353/test-results?q=WebGPUSwapBufferProviderTest.ReuseSwapBuffers&sortby=&groupby=

For most of these in Chromium, I've been fixing them to use spans, or at
least std::copy and std::copy_n, which do not have this language bug and
are specialized as memcpy when the type is trivially copyable. However,
when I tried to do that, I ran into issues with WGPUColor and
WGPUColorTransfer being different types. There's a lot of synthesized
code here I can't follow so, instead, just guard the memcpy with a zero
check to fix the undefined behavior.

Bug: chromium:40248746
Change-Id: I4041bfb750a3e0fcf56353bffefc0a2715603475
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/188900
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Auto-Submit: David Benjamin <davidben@google.com>
1 file changed
tree: 272c35e2c2b6828e251bd4910407024736c4cf67
  1. .github/
  2. .vscode/
  3. build_overrides/
  4. docs/
  5. generator/
  6. include/
  7. infra/
  8. scripts/
  9. src/
  10. test/
  11. third_party/
  12. tools/
  13. webgpu-cts/
  14. build
  15. buildtools
  16. testing
  17. .bazelrc
  18. .clang-format
  19. .clang-tidy
  20. .gitattributes
  21. .gitignore
  22. .gitmodules
  23. .gn
  24. AUTHORS
  25. BUILD.bazel
  26. BUILD.gn
  27. CMakeLists.txt
  28. CMakeSettings.json
  29. CODE_OF_CONDUCT.md
  30. codereview.settings
  31. CONTRIBUTING.md
  32. CPPLINT.cfg
  33. DEPS
  34. DIR_METADATA
  35. go.mod
  36. go.sum
  37. go_presubmit_support.py
  38. LICENSE
  39. OWNERS
  40. PRESUBMIT.py
  41. README.chromium
  42. README.md
  43. WORKSPACE.bazel
README.md

Build Status Matrix Space

Dawn, a WebGPU implementation

Dawn is an open-source and cross-platform implementation of the WebGPU standard. More precisely it implements webgpu.h that is a one-to-one mapping with the WebGPU IDL. Dawn is meant to be integrated as part of a larger system and is the underlying implementation of WebGPU in Chromium.

Dawn provides several WebGPU building blocks:

  • WebGPU C/C++ headers that applications and other building blocks use.
    • The webgpu.h version that Dawn implements.
    • A C++ wrapper for the webgpu.h.
  • A “native” implementation of WebGPU using platforms' GPU APIs: D3D12, Metal, Vulkan and OpenGL. See per API support for more details.
  • A client-server implementation of WebGPU for applications that are in a sandbox without access to native drivers
  • Tint is a compiler for the WebGPU Shader Language (WGSL) that can be used in standalone to convert shaders from and to WGSL.

Helpful links:

Documentation table of content

Developer documentation:

User documentation: (TODO, figure out what overlaps with the webgpu.h docs)

License

BSD 3-Clause License, please see LICENSE.

Disclaimer

This is not an officially supported Google product.