For non-x86 architectures, these forms directly translate to a
single instruction when possible. On x86 architectures,
XImmediate(dst, src, imm) where X is in {Lsl, ArithmeticShiftRight, And}
can be translated to:
MoveRegister(dst, src);
XImmediate(dst, imm);
in the general case since MoveRegister(dst, src) is a no-op if dst and
src are the same.
Also add versions of these assembler macros that take an OperandSize
and handle 32-bit OperandSizes appropriately on 64-bit architectures.
Ensure the implementation for LslImmediate and
ArithmeticShiftRightImmediate emits no instructions if shift == 0,
dst == src, and OperandSizeInBits(sz) == kBitsPerWord on all
architectures.
-----
Other changes:
Fix ConstantExpression::EmitMoveToLocation on ARM64 to match
other architectures, which allow any word-sized or less unboxed
integer representation.
Fill out ExtendValue on RISCV for previously unimplemented
OperandSizes, using the Zba and Zbb extensions when possible.
-----
TEST=vm/cc/Assembler_AndImmediate vm/cc/Assembler_LslImmediate
vm/cc/Assembler_ArithmeticShiftRightImmediate
Separated out of https://dart-review.googlesource.com/c/sdk/+/378706
for easier debugging/reviewing.
Change-Id: I721f1334784f7011a958ea8af29f0e56c620726c
Cq-Include-Trybots: luci.dart.try:vm-aot-linux-release-simarm_x64-try,vm-aot-linux-debug-x64-try,vm-aot-mac-release-arm64-try,vm-aot-mac-product-arm64-try,vm-aot-linux-product-x64-try,vm-aot-dwarf-linux-product-x64-try,vm-aot-linux-debug-simarm_x64-try,vm-linux-debug-x64-try,vm-mac-debug-arm64-try,vm-mac-release-arm64-try,vm-linux-debug-ia32-try,vm-aot-android-release-arm64c-try,vm-ffi-android-debug-arm64c-try,vm-aot-linux-debug-x64c-try,vm-linux-debug-x64c-try,vm-ffi-qemu-linux-release-arm-try,vm-ffi-qemu-linux-release-riscv64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/386180
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
When uploading CLs, the presubmit checks verify that the lines in the
diff are formatted correctly according to `git cl format runtime`.
However, when `buildtools/<os>-<arch>/clang/bin/clang-format` is
updated, it does not force reformatting of files that would be
reformatted.
This leads to two issues:
* Inconsistent style within the code base and within a single file.
* Spurious reformatting in CLs when (1) clang-format is used on the
whole file, or (2) the diff lines overlap.
`clang-format` doesn't change that frequently, so in general this is
not a large issue, but I've seen a bit too many "spurious formatting,
please revert" comments on CLs recently.
This CL formats the runtime to be in line with the current pinned
`clang-format`:
```
$ find runtime/ -iname *.h -o -iname *.cc | xargs buildtools/mac-arm64/clang/bin/clang-format -i
```
`git cl format` (which only formats changed lines, and does so with
`clang-format`) seems to not agree with itself, or clang-format, or
cpplint in a handful of places. This CL adds `// clang-format off`
for these. (See previous patchsets for the specific instances.)
TEST=A variety of bots including GCC, MacOS and Windows.
Change-Id: I470892e898971899fda14bb3b8f2c8efefd67686
Cq-Include-Trybots: luci.dart.try:vm-gcc-linux-try,vm-ffi-qemu-linux-release-riscv64-try,vm-ffi-qemu-linux-release-arm-try,vm-aot-win-debug-x64-try,vm-win-debug-x64c-try,vm-mac-debug-x64-try,vm-mac-debug-arm64-try,vm-aot-linux-debug-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/362780
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
When generating code for deferred units compiler
can't emit PC relative call to the shared Mint allocation
stub. This causes compiler to emit an indirect call
through a Code object. Such calls clobber CODE_REG
which is actually an allocatable register.
Fix this by using non-allocatable register instead of
CODE_REG when generating indirect calls through
Code object in AOT mode. Callees don't expect
anything useful in CODE_REG anyway because AOT
calling convetion does not use it.
TEST=vm/cc/{BranchLinkPreservesRegisters,JumpAndLinkPreservesRegisters,CallCodePreservesRegisters}
Bug: b/242559057
Cq-Include-Trybots: luci.dart.try:vm-aot-linux-release-arm64-try,vm-aot-linux-release-simarm_x64-try,vm-aot-linux-release-x64-try,vm-aot-linux-product-x64-try,vm-aot-obfuscate-linux-release-x64-try,vm-aot-optimization-level-linux-release-x64-try,vm-aot-linux-debug-simriscv64-try,vm-ffi-qemu-linux-release-riscv64-try
Change-Id: Ib1fdc1c104d0269d41bb1ab9cbe292ad28c7cd49
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/338127
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
Fix: Check handle contents for Smi.
Closes: https://github.com/flutter/flutter/issues/112726
Orignal CL description:
Makes `Dart_Handle` FFI returns behave as the following snippet:
```
Dart_Handle ExampleSnippet() {
Dart_Handle result = ...;
if (Dart_IsError(result)) {
Dart_PropagateError(result);
}
return result;
}
```
Also makes FFI consistent with Dart_NativeFunctions, which will
automatically throw upon return if Dart_SetReturnValue set the result
to an error.
`UnhandledExceptions` cannot flow out into Dart generated code. So,
the implementation needs to be in `FfiCallInstr::EmitNativeCode`.
Using `Dart_IsError` is slow compared to a machine code class id
check. So, we should do the handle unwrapping and class id check in
machine code.
Unwrapping Handles in machine code is only safe when the GC is
guaranteed to not run: Either (1) in `kThreadInGenerated`, or (2) in
`kThreadInNative`, but only when transitioned into safepoint. So, the
handle cannot be unwrapped immediately after the FFI call in machine code. We first need to transition back to generated.
This means we need to transition again to native to do the actual
`Dart_PropagateError` call. We can do so without the stub in JIT
because we never return with normal control flow.
Performance impact of this change is within benchmark noise in both
JIT and AOT.
Size impact is 42 bytes on x64, which is 10% in AOT and 12% in JIT.
For more numbers see: go/dart-ffi-handle-error
TEST=runtime/bin/ffi_test/ffi_test_functions_vmspecific.cc
TEST=tests/ffi/vmspecific_handle_test.dart
Closes: https://github.com/dart-lang/sdk/issues/49936
Change-Id: Id8edfd841a7d6246438386007d83747868a0a151
Cq-Include-Trybots: luci.dart.try:vm-canary-linux-debug-try,vm-ffi-android-debug-arm64c-try,vm-ffi-android-debug-arm-try,vm-kernel-gcc-linux-try,vm-kernel-linux-debug-x64-try,vm-kernel-linux-debug-x64c-try,vm-kernel-msvc-windows-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-asan-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-tsan-linux-release-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-precomp-ffi-qemu-linux-release-riscv64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-mac-release-arm64-try,vm-kernel-precomp-win-debug-x64c-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/262342
Reviewed-by: Martin Kustermann <kustermann@google.com>
Auto-Submit: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
This reverts commit d9c442bce8.
Reason for revert: https://github.com/flutter/flutter/issues/112726
Original change's description:
> [vm/ffi] Throw on returning `Error` in `Handle`
>
> Makes `Dart_Handle` FFI returns behave as the following snippet:
>
> ```
> Dart_Handle ExampleSnippet() {
> Dart_Handle result;
> if (Dart_IsError(result)) {
> Dart_PropagateError(result);
> }
> return result;
> }
> ```
>
> Also makes FFI consistent with Dart_NativeFunctions, which will
> automatically throw upon return if Dart_SetReturnValue set the result
> to an error.
>
> `UnhandledExceptions` cannot flow out into Dart generated code. So,
> the implementation needs to be in `FfiCallInstr::EmitNativeCode`.
>
> Using `Dart_IsError` is slow compared to a machine code class id
> check. So, we should do the handle unwrapping and class id check in
> machine code.
>
> Unwrapping Handles in machine code is only safe when the GC is
> guaranteed to not run: Either (1) in `kThreadInGenerated`, or (2) in
> `kThreadInNative`, but only when transitioned into safepoint. So, the
> handle cannot be unwrapped immediately after the FFI call in machine code. We first need to transition back to generated.
>
> This means we need to transition again to native to do the actual
> `Dart_PropagateError` call. We can do so without the stub in JIT
> because we never return with normal control flow.
>
> Performance impact of this change is within benchmark noise in both
> JIT and AOT.
> Size impact is 42 bytes on x64, which is 10% in AOT and 12% in JIT.
>
> For more numbers see: go/dart-ffi-handle-error
>
> TEST=runtime/bin/ffi_test/ffi_test_functions_vmspecific.cc
> TEST=tests/ffi/vmspecific_handle_test.dart
>
> Closes: https://github.com/dart-lang/sdk/issues/49936
> Change-Id: Ie8fabeb6d53bc80689541bc4470cb37ee2200581
> Cq-Include-Trybots: luci.dart.try:vm-canary-linux-debug-try,vm-ffi-android-debug-arm64c-try,vm-ffi-android-debug-arm-try,vm-kernel-gcc-linux-try,vm-kernel-linux-debug-x64-try,vm-kernel-linux-debug-x64c-try,vm-kernel-msvc-windows-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-asan-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-tsan-linux-release-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-precomp-ffi-qemu-linux-release-riscv64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-mac-release-arm64-try,vm-kernel-precomp-win-debug-x64c-try
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/261603
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Commit-Queue: Daco Harkes <dacoharkes@google.com>
TBR=kustermann@google.com,rmacnak@google.com,dacoharkes@google.com,dart-scoped@luci-project-accounts.iam.gserviceaccount.com
Change-Id: I94cc63de16b54db2b0a4f92759c39a1e569b8e63
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Cq-Include-Trybots: luci.dart.try:vm-canary-linux-debug-try,vm-ffi-android-debug-arm64c-try,vm-ffi-android-debug-arm-try,vm-kernel-gcc-linux-try,vm-kernel-linux-debug-x64-try,vm-kernel-linux-debug-x64c-try,vm-kernel-msvc-windows-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-asan-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-tsan-linux-release-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-precomp-ffi-qemu-linux-release-riscv64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-mac-release-arm64-try,vm-kernel-precomp-win-debug-x64c-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/262270
Reviewed-by: Zach Anderson <zra@google.com>
Reviewed-by: Liam Appelbe <liama@google.com>
Commit-Queue: Zach Anderson <zra@google.com>
Makes `Dart_Handle` FFI returns behave as the following snippet:
```
Dart_Handle ExampleSnippet() {
Dart_Handle result;
if (Dart_IsError(result)) {
Dart_PropagateError(result);
}
return result;
}
```
Also makes FFI consistent with Dart_NativeFunctions, which will
automatically throw upon return if Dart_SetReturnValue set the result
to an error.
`UnhandledExceptions` cannot flow out into Dart generated code. So,
the implementation needs to be in `FfiCallInstr::EmitNativeCode`.
Using `Dart_IsError` is slow compared to a machine code class id
check. So, we should do the handle unwrapping and class id check in
machine code.
Unwrapping Handles in machine code is only safe when the GC is
guaranteed to not run: Either (1) in `kThreadInGenerated`, or (2) in
`kThreadInNative`, but only when transitioned into safepoint. So, the
handle cannot be unwrapped immediately after the FFI call in machine code. We first need to transition back to generated.
This means we need to transition again to native to do the actual
`Dart_PropagateError` call. We can do so without the stub in JIT
because we never return with normal control flow.
Performance impact of this change is within benchmark noise in both
JIT and AOT.
Size impact is 42 bytes on x64, which is 10% in AOT and 12% in JIT.
For more numbers see: go/dart-ffi-handle-error
TEST=runtime/bin/ffi_test/ffi_test_functions_vmspecific.cc
TEST=tests/ffi/vmspecific_handle_test.dart
Closes: https://github.com/dart-lang/sdk/issues/49936
Change-Id: Ie8fabeb6d53bc80689541bc4470cb37ee2200581
Cq-Include-Trybots: luci.dart.try:vm-canary-linux-debug-try,vm-ffi-android-debug-arm64c-try,vm-ffi-android-debug-arm-try,vm-kernel-gcc-linux-try,vm-kernel-linux-debug-x64-try,vm-kernel-linux-debug-x64c-try,vm-kernel-msvc-windows-try,vm-kernel-optcounter-threshold-linux-release-x64-try,vm-kernel-precomp-asan-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-tsan-linux-release-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-precomp-ffi-qemu-linux-release-riscv64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-mac-release-arm64-try,vm-kernel-precomp-win-debug-x64c-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/261603
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Moves `RangeCheck` from the intrinsifier to the assembler.
Also, unifies the signature and semantics and adds documentation.
TEST=refactor
Change-Id: I274e5e46fde6a6e8baf30d8b732932f4f46d5855
Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-debug-simriscv64-try,vm-kernel-precomp-linux-debug-simriscv64-try,vm-kernel-linux-release-simarm64-try,vm-kernel-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm-try,vm-precomp-ffi-qemu-linux-release-riscv64-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-kernel-linux-debug-ia32-try,vm-kernel-linux-debug-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/261681
Reviewed-by: Tess Strickland <sstrickl@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Adding this representation allows us to create slots for storing
and retrieving values from uint16_t-typed object fields in the runtime.
Also generalize BoxUint8Instr to BoxSmallIntInstr, which holds any
unboxed integer representation where the value is guaranteed to fit
into a Smi.
To unify the implementation of BoxSmallIntInstr across architectures,
we add ExtendValue(Register dst, Register src, OperandSize sz), which
extends the sz-sized value in src to a full register size in dst. If
sz is a signed OperandSize, then the resulting value is sign
extended appropriately.
We also add MoveAndSmiTagRegister / ExtendAndSmiTagValue, which is like
the base operation but also tags the value as a Smi. On some
architectures, this can be performed using a single instruction.
Also adds sbfx/ubfx on ARM for use in ExtendValue.
TEST=Existing tests for BoxSmallIntInstr, followup CL for the new
representation.
Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-debug-x64-try,vm-kernel-linux-debug-x64c-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64c-try,vm-kernel-precomp-nnbd-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-nnbd-linux-debug-simarm_x64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-nnbd-linux-debug-ia32-try,vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-simarm64-try,vm-kernel-precomp-linux-debug-simarm64c-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-nnbd-linux-debug-simarm_x64-try,vm-kernel-linux-debug-simarm64c-try,vm-kernel-precomp-nnbd-linux-release-simarm64-try,vm-precomp-ffi-qemu-linux-release-arm-try
Change-Id: I9c0b3a23f5e28480e0bfbde55b9494f7b822dcfa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/203761
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Assembler now always knows whether LR contains return address
or can be safely cloberred.
TEST=tested through normal test suite
Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-ffi-android-release-arm64-try,vm-ffi-android-release-arm-try,vm-kernel-precomp-android-release-arm_x64-try,vm-kernel-precomp-android-release-arm64-try
Change-Id: I0b436509389cfd29ee413fd28930fb2d6b07616e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174468
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
The only architecture-specific part of type testing stubs (TTS) is which
registers get saved/restored across SubtypeTestCache stub calls in the
slow TTS implementation, which is now a register mask constant in the
TypeTestABI struct.
This CL also:
* Creates a single definition of OperandSize in assembler_base.h. Moves
OperandSize into the compiler namespace. assembler_base.h. Renames
constants common to all architectures to neutral names (e.g., kWord =>
kFourBytes), since "word" has different meanings across architectures.
* Creates a new JumpDistance enum for kNearJump/kFarJump in
AssemblerBase and replace existing bool uses with the constants.
* Adds JumpDistance arguments to some of the generalized Assembler
methods so they aren't forced to use far jumps on IA32/X64. These
added JumpDistance arguments are ignored on ARM architectures.
* Adds a new generalized Assembler::LoadIndexedPayload method for
loading indexed objects out of post-header variable-length payloads.
* Moved the OperandSize argument for LoadForOffset and similar methods
on 32-bit ARM from being the first argument to being the second to
last argument just to match other architectures, and to allow it to
have a default value of kFourBytes.
TEST=Run on trybots of all architectures.
Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-linux-debug-ia32-try,vm-kernel-nnbd-linux-debug-ia32-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-nnbd-linux-debug-simarm_x64-try,vm-kernel-precomp-nnbd-linux-debug-x64-try,vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-simarm64-try,vm-kernel-nnbd-linux-release-simarm-try,vm-kernel-nnbd-linux-release-simarm64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-nnbd-linux-release-simarm64-try
Change-Id: Ia930613e96db4d1ab324c5a355dca8994d2a77f0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/172160
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Take full advantage of PushPair (stp) in code generation
visitors; use PushRegisterPair for ThrowErrorSlowPathCode.
This change improves Flutter Gallery code size by:
Instr: -0.24%
Total: -0.15%
Change-Id: Icba42cb956b07966861b52d3a8653d21eafab3b9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/125971
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
This is the next step towards preventing compiler from directly peeking
into runtime and instead interact with runtime through a well defined
surface. The goal of the refactoring to locate all places where compiler
accesses some runtime information and partion those accesses into two
categories:
- creating objects in the host runtime (e.g. allocating strings, numbers, etc)
during compilation;
- accessing properties of the target runtime (e.g. offsets of fields) to
embed those into the generated code;
This change introduces dart::compiler and dart::compiler::target namespaces.
All code in the compiler will gradually be moved into dart::compiler namespace.
One of the motivations for this change is to be able to prevent access to
globally defined host constants like kWordSize by shadowing them in the
dart::compiler namespace.
The nested namespace dart::compiler::target hosts all information about
target runtime that compiler could access, e.g. compiler::target::kWordSize
defines word size of the target which will eventually be made different
from the host kWordSize (defined by dart::kWordSize).
The API for compiler to runtime interaction is placed into compiler_api.h.
Note that we still permit runtime to access compiler internals directly -
this is not going to be decoupled as part of this work.
Issue https://github.com/dart-lang/sdk/issues/31709
Change-Id: If4396d295879391becfa6c38d4802bbff81f5b20
Reviewed-on: https://dart-review.googlesource.com/c/90242
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
New folder structure (nested under vm/):
- compiler/
- jit/ - JIT specific code
- aot/ - AOT specific code
- backend/ - all middle-end and back-end code (IL, flow graph)
- assembler/ - assemblers and disassemblers
- frontend/ - front ends (AST -> IL, Kernel -> IL)
compiler/README.md would be the documentation root for the compiler
pipeline
Bug: https://github.com/dart-lang/sdk/issues/30575
Change-Id: I2dfd9688793bff737f7632ddc77fca766875ce36
Reviewed-on: https://dart-review.googlesource.com/2940
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Ryan Macnak