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dawn / tint / ea3eee988528af5802707ee07d89c48eba4a6e85
commitea3eee988528af5802707ee07d89c48eba4a6e85[log] [tgz]
authorBen Clayton <bclayton@google.com>Fri Dec 03 17:51:48 2021 +0000
committerBen Clayton <bclayton@google.com>Fri Dec 03 17:51:48 2021 +0000
tree72e2bdd30a53ba7e1ba812fd0bba2d21e3a947e7
parentc2703228840fd998611d069070f2aa5acf772b5e [diff]
resolver: Migrate validation to behavior analysis

Migrate some of the validation logic over to use the results of behavior
analysis.

The most significant changes are:
* Unreachable-statements now consider merge-points of control flow. For
  example, if all branches of a if-statement or switch-statement either
  return or discard, the next statement will be considered unreachable.
* Unreachable statements are no longer an error, but a warning. See
  https://github.com/gpuweb/gpuweb/issues/2378.
* Statements that follow a loops that does not break, or have a
  conditional will now be considered unreachable.
* Unreachable statements produced by the SPIR-V reader are now removed
  using the new RemoveUnreachableStatements transform.

Some other new changes include additional validation for the continuing
block for for-loops, to match the rules of a loop continuing block.
The new cases this validation is testing for are not expressible in
WGSL, but some transforms may produce complex continuing statements that
might violate these rules. All the writers are able to decay these
complex for-loop continuing statements to regular loops.

Bug: tint:1302
Change-Id: I0d8a48c73d5d5c30a1cddf92cc3383a692a58e61
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/71500
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
59 files changed
tree: 72e2bdd30a53ba7e1ba812fd0bba2d21e3a947e7
  1. .vscode/
  2. build_overrides/
  3. docs/
  4. fuzzers/
  5. include/
  6. infra/
  7. kokoro/
  8. samples/
  9. src/
  10. test/
  11. third_party/
  12. tools/
  13. .clang-format
  14. .gitignore
  15. .gn
  16. AUTHORS
  17. BUILD.gn
  18. CMakeLists.txt
  19. CMakeSettings.json
  20. CODE_OF_CONDUCT.md
  21. CONTRIBUTING.md
  22. CPPLINT.cfg
  23. DEPS
  24. Doxyfile
  25. LICENSE
  26. OWNERS
  27. PRESUBMIT.py
  28. README.md
  29. standalone.gclient
  30. tint_overrides_with_defaults.gni
README.md

Tint

Tint is a compiler for the WebGPU Shader Language (WGSL).

This is not an officially supported Google product.

Requirements

  • Git
  • CMake (3.10.2 or later)
  • Ninja (or other build tool)
  • Python, for fetching dependencies
  • depot_tools in your path

Build options

  • TINT_BUILD_SPV_READER : enable the SPIR-V input reader (off by default)
  • TINT_BUILD_WGSL_READER : enable the WGSL input reader (on by default)
  • TINT_BUILD_SPV_WRITER : enable the SPIR-V output writer (on by default)
  • TINT_BUILD_WGSL_WRITER : enable the WGSL output writer (on by default)
  • TINT_BUILD_FUZZERS : enable building fuzzzers (off by default)

Building

Tint uses Chromium dependency management so you need to install depot_tools and add it to your PATH.

Getting source & dependencies

# Clone the repo as "tint"
git clone https://dawn.googlesource.com/tint tint
cd tint

# Bootstrap the gclient configuration
cp standalone.gclient .gclient

# Fetch external dependencies and toolchains with gclient
gclient sync

Compiling using CMake + Ninja

mkdir -p out/Debug
cd out/Debug
cmake -GNinja ../..
ninja # or autoninja

Compiling using CMake + make

mkdir -p out/Debug
cd out/Debug
cmake ../..
make # -j N for N-way parallel build

Compiling using gn + ninja

mkdir -p out/Debug
gn gen out/Debug
autoninja -C out/Debug

Fuzzers on MacOS

If you are attempting fuzz, using TINT_BUILD_FUZZERS=ON, the version of llvm in the XCode SDK does not have the needed libfuzzer functionality included.

The build error that you will see from using the XCode SDK will look something like this:

ld: file not found:/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/11.0.0/lib/darwin/libclang_rt.fuzzer_osx.a

The solution to this problem is to use a full version llvm, like what you would get via homebrew, brew install llvm, and use something like CC=<path to full clang> cmake .. to setup a build using that toolchain.

Checking [chromium-style] issues in CMake builds

The gn based work flow uses the Chromium toolchain for building in anticipation of integration of Tint into Chromium based projects. This toolchain has additional plugins for checking for style issues, which are marked with [chromium-style] in log messages. This means that this toolchain is more strict then the default clang toolchain.

In the future we will have a CQ that will build this work flow and flag issues automatically. Until that is in place, to avoid causing breakages you can run the [chromium-style] checks using the CMake based work flows. This requires setting CC to the version of clang checked out by gclient sync and setting the TINT_CHECK_CHROMIUM_STYLE to ON.

mkdir -p out/style
cd out/style
cmake ../..
CC=../../third_party/llvm-build/Release+Asserts/bin/clang cmake -DTINT_CHECK_CHROMIUM_STYLE=ON ../../ # add -GNinja for ninja builds

Issues

Please file any issues or feature requests at https://bugs.chromium.org/p/tint/issues/entry

Contributing

Please see the CONTRIBUTING and CODE_OF_CONDUCT files on how to contribute to Tint.

Tint has a process for supporting experimental extensions.