This CL introduces a way to mark all instances of a class as deeply
immutable.
In order to statically verify that all instances of a deeply immutable
class are immutable, a deeply immutable classes must have the following
properties:
1. All instance fields must
1. have a deeply immutable type,
2. be final, and
3. be non-late.
2. The class must be `final` or `sealed`. This ensures no
non-deeply-immutable subtypes are added by external code.
3. All subtypes must be deeply immutable. This ensures 1.1 can be
trusted.
4. The super type must be deeply immutable (except for Object).
Note that instances of some classes in the VM are deeply immutable
while their class cannot be marked immutable.
* SendPort, Capability, RegExp, and StackTrace are not `final` and
can be implemented by external code.
* UnmodifiableTypedDataViews do not have a public type. (It was
recently deprecated.)
See runtime/docs/deeply_immutable.md for more details.
Use case:
This enables attaching a `Dart_FinalizableHandle` to a deeply immutable
object and the deeply immutable object with other isolates in the same
isolate group.
(Note that `NativeFinalizer`s live in an isolate, and not an isolate
group. So this should currently _not_ be used with `NativeFinalizer`s.
See https://github.com/dart-lang/sdk/issues/55062 for making a
`NativeFinalizer.shared(` that would live in an isolate group instead
of in an isolate.)
Implementation details:
Before this CL, the `ImmutableBit` in the object header was only ever
set to true for predefined class ids (and for const objects). After
this CL, the bit can also be set to true for non const instances of
user-defined classes. The object allocation and initialization code has
been changed to deal with this new case. The immutability of a class is
saved in the class state bits. On object allocation and initialization
the immutability bit is read from the class for non-predefined class
ids.
TEST=runtime/tests/vm/dart/isolates/fast_object_copy2_test.dart
TEST=runtime/vm/isolate_reload_test.cc
TEST=tests/lib/isolate/deeply_immutable_*
Bug: https://github.com/dart-lang/sdk/issues/55120
Bug: https://github.com/dart-lang/sdk/issues/54885
Change-Id: Ib97fe589cb4f81673cb928c93e3093838d82132d
Cq-Include-Trybots: luci.dart.try:vm-aot-android-release-arm64c-try,vm-aot-android-release-arm_x64-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-kernel-linux-debug-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-linux-debug-ia32-try,vm-linux-debug-x64-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
Cq-Include-Trybots: dart-internal/g3.dart-internal.try:g3-cbuild-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/354902
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Remove compile time errors from null_test.dart and move them into
a new static error test file.
Add the other mixin application syntax.
This makes it so much easier to run and debug null_test.dart on a
backend.
Change-Id: I126a580ccf477962cd90dccff267034bd9b35a2b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/254722
Commit-Queue: Erik Ernst <eernst@google.com>
Auto-Submit: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Erik Ernst <eernst@google.com>
Daco Harkes