|author||David Neto <email@example.com>||Mon Dec 20 16:46:55 2021 +0000|
|committer||Tint LUCI CQ <firstname.lastname@example.org>||Mon Dec 20 16:46:55 2021 +0000|
spirv-writer: Fix termination of basic blocks There are a few places where a branch or return is created, conditionally on whether a terminator was the last thing seen. The goal is to generate a SPIR-V basic block terminator exactly when needed, and to avoid generating a branch or return immediately after a prior terminator. Previously, the decision was based on the last thing seen in the AST. But we should instead check the emitted SPIR-V instead. This fixes cases such as a break or return inside an else-if. That's because an if/elseif is actually a selection inside a selection. Looking at the AST only works when trying to terminate the *inside* selection. In the outer recursive call, the last AST node is no longer a terminator, and we would skip generating the branch to the merge block. Fixed: tint:1315 Change-Id: I6b886ce85d1d681f2063997e469e0c1b4e5973a2 Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/73480 Kokoro: Kokoro <email@example.com> Auto-Submit: David Neto <firstname.lastname@example.org> Reviewed-by: James Price <email@example.com> Commit-Queue: James Price <firstname.lastname@example.org>
Tint is a compiler for the WebGPU Shader Language (WGSL).
This is not an officially supported Google product.
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)
Tint uses Chromium dependency management so you need to install depot_tools and add it to your PATH.
# 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
mkdir -p out/Debug cd out/Debug cmake -GNinja ../.. ninja # or autoninja
mkdir -p out/Debug cd out/Debug cmake ../.. make # -j N for N-way parallel build
mkdir -p out/Debug gn gen out/Debug autoninja -C out/Debug
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.
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
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
Please file any issues or feature requests at https://bugs.chromium.org/p/tint/issues/entry
Please see the CONTRIBUTING and CODE_OF_CONDUCT files on how to contribute to Tint.
Tint has a process for supporting experimental extensions.