Files
sdk/runtime/vm/ffi
Daco Harkes 9a8508ebff [vm/ffi] FfiNative assets
Adds support for `asset: 'asset-id'` in `FfiNative`s.
Symbols in assets are resolved by
1. the provided [asset] (the bulk of this CL),
2. the native resolver set with `Dart_SetFfiNativeResolver` in
   `dart_api.h` (old behavior), and
3. the current process.

Symbols in assets are resolved by the Dart VM through the mapping
provided in the `vm:ffi:native_assets` library:
```
@pragma('vm:ffi:native-assets', {
  "linux_x64": {
    "<asset1>": [
      "absolute",
      "<absolute-path>"
    ],
    "<asset2>": [
      "relative",
      "<relative-path>"
    ],
    "<asset3>": [
      "system",
      "<system-path>"
    ],
    "<asset4>": [
      "process",
    ],
    "<asset5>": [
      "executable",
    ],
  }
})
library;
```

There are 5 asset path types. Symbols resolved in these asset types are
resolved as follows.
A. Absolute paths are dlopened, after which the symbol is looked up.
B. Relative paths are resolved relative to `Platform.script.uri`, and
   dlopened, after which the symbol is looked up.
C. System paths are treated as absolute paths. (But we might explicitly
   try to use `PATH` in the future.)
D. Symbols looked up in Process assets are looked up in the current
   process.
E. Symbols looked up in Executable assets are looked up in the current
   executable.

The native assets mapping can be provided in three ways.

X. In the invocation to `gen_kernel` with the `--native-assets`
   argument. This uses the gen_kernel entry point for compiling
   kernel.
Y. By placing a `native_assets.yaml` next to the
   `package_config.json` used by the isolate group. This works for
   `dart <source file>` and `Isolate.spawnUri(<dart source file>)`.
   This uses the kernel_service entry point for compiling kernel.
Z. By sending a String containing the native assets mapping when
   invoking the kernel_service directly from within the VM. Currently,
   only used for unit tests.

TEST=tests/ffi/native_assets/asset_*_test.dart (X)
TEST=tests/ffi/native_assets/infer_native_assets_yaml_*.dart (Y)
TEST=runtime/vm/ffi/native_assets_test.cc (Z)

The library is synthesized from yaml in pkg:vm as AST.

Design doc: go/dart-native-assets

Bug: https://github.com/dart-lang/sdk/issues/49803
Change-Id: I8bf7000bfcc03b362948efd3baf168838948e6b9
Cq-Include-Trybots: luci.dart.try:vm-ffi-android-debug-arm-try,vm-ffi-android-debug-arm64c-try,vm-precomp-ffi-qemu-linux-release-arm-try,vm-kernel-nnbd-mac-debug-arm64-try,vm-kernel-nnbd-mac-debug-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-reload-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-precomp-nnbd-linux-debug-x64-try,vm-kernel-precomp-win-debug-x64c-try,vm-kernel-precomp-nnbd-mac-release-arm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/264842
Reviewed-by: Martin Kustermann <kustermann@google.com>
2023-01-18 21:08:38 +00:00
..