Find a file
Tess Strickland 291051e02d [vm/compiler] Add an instruction to adjust unsafe untagged addresses.
ComputeElementAddress takes a base untagged address, an index, an index
scale, and an offset and returns base + (index * scale) + offset as an
untagged address.

This removes the last conversions between untagged and unboxed integers
for untagged GC-movable pointers. The only remaining conversions are
the following cases, which all involve non-GC-movable pointers:

1. Calls to the FFI resolver (on IA32 only).
2. Returning nullptr when a pointer to memory is expected in
   exceptional returns from FFI callbacks.
3. Converting user-provided integers to FFI pointer objects and back.

In addition, we no longer add the data field to materializations of
typed data views, but instead recompute the data field in
DeferredObject::Fill(). This removes the last source of unsafe untagged
pointers that may have arbitrary lifetimes in the flow graph.

Thus, we can now verify in the FlowGraphChecker that there are no
GC-triggering instructions between the creation of an untagged
GC-movable pointer and its use (including the use itself). To do this,
this CL adds a predicate MayCreateUnsafeUntaggedPointer to definitions,
which by default returns true for kUntagged results, false otherwise,
and should only be overwritten in cases where the result can be proven
to not be a untagged GC-movable pointer.

TEST=vm/dart/regress_54710_il_test
     vm/cc/AllocationSinking_NoViewDataMaterialization

Fixes: https://github.com/dart-lang/sdk/issues/54710
Cq-Include-Trybots: luci.dart.try:vm-aot-android-release-arm64c-try,vm-aot-linux-debug-x64-try,vm-aot-linux-debug-x64c-try,vm-aot-mac-release-arm64-try,vm-aot-mac-release-x64-try,vm-aot-obfuscate-linux-release-x64-try,vm-aot-optimization-level-linux-release-x64-try,vm-appjit-linux-debug-x64-try,vm-asan-linux-release-x64-try,vm-checked-mac-release-arm64-try,vm-eager-optimization-linux-release-ia32-try,vm-eager-optimization-linux-release-x64-try,vm-ffi-android-debug-arm-try,vm-ffi-android-debug-arm64c-try,vm-ffi-qemu-linux-release-arm-try,vm-ffi-qemu-linux-release-riscv64-try,vm-fuchsia-release-x64-try,vm-linux-debug-ia32-try,vm-linux-debug-x64c-try,vm-mac-debug-arm64-try,vm-mac-debug-x64-try,vm-msan-linux-release-x64-try,vm-reload-linux-debug-x64-try,vm-reload-rollback-linux-debug-x64-try,vm-ubsan-linux-release-x64-try,vm-win-release-ia32-try
Change-Id: Ie172a8bd0330a728a4f151478664a530f8d9b38a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/354862
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2024-03-22 19:03:31 +00:00
.dart_tool
.github
benchmarks
build
docs
pkg
runtime
samples
sdk
tests
third_party
tools
utils
.clang-format
.gitattributes
.gitconfig
.gitignore
.gn
.mailmap
.style.yapf
AUTHORS
BUILD.gn
CHANGELOG.md
codereview.settings
CONTRIBUTING.md
DEPS
LICENSE
OWNERS
PATENT_GRANT
PRESUBMIT.py
README.dart-sdk
README.md
sdk.code-workspace
sdk_args.gni
SECURITY.md
WATCHLISTS

Dart

An approachable, portable, and productive language for high-quality apps on any platform

Dart is:

  • Approachable: Develop with a strongly typed programming language that is consistent, concise, and offers modern language features like null safety and patterns.

  • Portable: Compile to ARM, x64, or RISC-V machine code for mobile, desktop, and backend. Compile to JavaScript or WebAssembly for the web.

  • Productive: Make changes iteratively: use hot reload to see the result instantly in your running app. Diagnose app issues using DevTools.

Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:

  • Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.

  • Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).

Dart platforms illustration

License & patents

Dart is free and open source.

See LICENSE and PATENT_GRANT.

Using Dart

Visit dart.dev to learn more about the language, tools, and to find codelabs.

Browse pub.dev for more packages and libraries contributed by the community and the Dart team.

Our API reference documentation is published at api.dart.dev, based on the stable release. (We also publish docs from our beta and dev channels, as well as from the primary development branch).

Building Dart

If you want to build Dart yourself, here is a guide to getting the source, preparing your machine to build the SDK, and building.

There are more documents on our wiki.

Contributing to Dart

The easiest way to contribute to Dart is to file issues.

You can also contribute patches, as described in Contributing.