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Daco Harkes 0bcb0c934d [vm/ffi] Add _Compound _offsetInBytes field
This CL changes compounds (structs, unions, and arrays) to be backed
by a TypedDataBase and an int offset.

Before this CL, the compounds where only backed by a TypedDataBase.
This leads to the following issues:

1. Access to nested structs required code for allocating new typed data
   views or pointers, which the optimizer then had to prevent from
   being allocated after inlining.
2. Runtime branching on whether the TypedDataBase was a Pointer or
   TypedData increased code size and prevented inlining.
   https://github.com/dart-lang/sdk/issues/54892
   This could not be properly optimized if in AOT both typed
   data and pointer were flowing into the same compound.
3. Constructing TypedData views required calculating the length of the
   view.

After this CL, accessing nested compounds will lead to accesses on the
original TypedDataBase with an extra offset.

This removes the polymorphism on TypedData vs Pointer, because the
final int/float/Pointer accesses in nested compounds operate on
TypedDataBase.

Also, it simplifies creating an `offsetBy` accessor, because it will
no longer have to be polymorphic in typed data vs pointer, nor will it
have to calculate the length of the field.

Implementation details:

* The changes in the CFE and patch files are straightforward.
* VM: Struct-by-value returns (or callback params) are initialized
  with an offsetInBytes of 0.
* VM: Struct-by-value arguments (and callback return) need to read out
  the offsetInBytes. Before this CL we were passing in the TypedData
  as tagged value. With this CL we are passing the TypedData as tagged
  value and the offset as unboxed int, from 1 IL input to 2 IL
  inputs. (The alternative would have been to take the compound as
  a tagged value, but that would have prevented optimizations from not
  allocating the compound object in the optimizer.
  The FfiCallInstr is updated to have two definitions for the case
  where we were passing in the TypedData previously.
  The NativeReturnInstr is refactored to be able to take two inputs
  instead of 1. (Note that we don't have VariadicInstr only
  VariadicDefinition in the code base. So the instruction is _not_
  implemented as variadic, rather as having a fixed length of 2.)
* dart2wasm does no longer support nested compounds due to the
  compound implementation only storing a pointer address.
  https://github.com/dart-lang/sdk/issues/55083

Intending to land this after
https://dart-review.googlesource.com/c/sdk/+/353101.

TEST=test/ffi

CoreLibraryReviewExempt: VM and WASM-only implementation change.
Closes: https://github.com/dart-lang/sdk/issues/54892
Bug: https://github.com/dart-lang/sdk/issues/44589
Change-Id: I8749e21094bf8fa2d5ff1e48b6b002c375232eb5
Cq-Include-Trybots: dart-internal/g3.dart-internal.try:g3-cbuild-try
Cq-Include-Trybots: 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-aot-win-debug-arm64-try,vm-aot-win-debug-x64-try,vm-aot-win-debug-x64c-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-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,vm-win-debug-arm64-try,vm-win-debug-x64-try,vm-win-debug-x64c-try,vm-win-release-ia32-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/354226
Reviewed-by: Tess Strickland <sstrickl@google.com>
2024-03-26 17:14:13 +00:00
.dart_tool [infra] re-land work to auto-generate .dart_tool/package_config.json 2022-04-12 17:21:02 +00:00
.github Clarify risk and multiple channel CLs in cherry-pick request template. 2024-03-26 15:29:23 +00:00
benchmarks [benchmarks] Fix benchmarks warming up incorrectly. 2024-02-22 14:38:19 +00:00
build [infra] Update alpine sysroot 2024-03-21 10:43:15 +00:00
docs Add requirement to fix downstream repositories 2024-03-13 14:13:49 +00:00
pkg [vm/ffi] Add _Compound _offsetInBytes field 2024-03-26 17:14:13 +00:00
runtime [vm/ffi] Add _Compound _offsetInBytes field 2024-03-26 17:14:13 +00:00
samples fix use of deprecated members in ffi samples 2024-01-31 22:31:59 +00:00
sdk [vm/ffi] Add _Compound _offsetInBytes field 2024-03-26 17:14:13 +00:00
tests Add static tests for external extension members on extension types 2024-03-26 15:43:19 +00:00
third_party [dds/dap] Bump package:dap and the version used by DDS 2024-02-29 19:22:19 +00:00
tools [infra] Fail hard if starting RBE fails. 2024-03-26 11:10:48 +00:00
utils [ VM / DDS ] Add --print-dtd-uri flag and launch DTD from the correct snapshot for AOT 2024-03-21 19:50:46 +00:00
.clang-format
.gitattributes Fix allowing Windows newlines in sh files. 2024-03-19 11:27:14 +00:00
.gitconfig [infra] Add documentation to .gitconfig 2018-06-11 18:24:16 +00:00
.gitignore [infra] Support testing with RBE on Windows. 2024-02-29 10:33:09 +00:00
.gn [build] Switch to Fuchsia core SDK. 2023-11-10 19:23:11 +00:00
.mailmap Fixed various typos in a lot of files 2022-07-25 12:21:59 +00:00
.style.yapf Mass format python with yapf 2019-08-05 20:34:31 +00:00
AUTHORS Simplify the license situation 2022-09-14 21:06:22 +00:00
BUILD.gn [vm] Do not bundle dart.lib in the Dart SDK 2024-02-15 14:09:37 +00:00
CHANGELOG.md [dart:js_interop] Add ExternalDartReference 2024-03-26 15:43:19 +00:00
codereview.settings [infra] Default presubmits to use python3 2021-08-24 08:20:47 +00:00
CONTRIBUTING.md Update CONTRIBUTING.md 2023-11-20 09:29:37 +00:00
DEPS Bump pub to 3f0df78417f7c112b933fbcdc1c5c87bde680cb1 2024-03-25 15:19:58 +00:00
LICENSE Update LICENSE 2021-04-08 07:57:10 +00:00
OWNERS [infra] Remove .packages OWNERS rule. 2024-03-25 15:43:48 +00:00
PATENT_GRANT Rename patent file 2019-08-16 12:03:17 +00:00
PRESUBMIT.py [presubmit] Force read files as UTF-8 2024-03-05 14:25:09 +00:00
README.dart-sdk Update README.dart-sdk for inclusion of AOT snapshots 2023-11-21 10:33:22 +00:00
README.md Update readme content 2023-12-18 15:30:58 +00:00
sdk.code-workspace [cleanup] Remove co19_2 and other references to _2 suites 2023-11-22 11:15:57 +00:00
sdk_args.gni [gn] Add an option to specify the sdk_hash 2024-03-07 04:11:48 +00:00
SECURITY.md Add link to published advisories 2022-02-08 19:45:07 +00:00
WATCHLISTS [analyzer] Properly close analyzer WATCHLISTS entry 2023-12-10 18:02:25 +00:00

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