This CL introduces a new kernel-to-kernel pass in Wasm backend to
compile `FfiNative`-annotated external functions to external functions
with `wasm:import` pragmas.
The new pass `WasmFfiNativeTransformer` extends `FfiNativeTransformer`.
Some `FfiNativeTransformer` methods made public to allow reuse in the
pass.
The conversion works like this: when we see a member like:
@FfiNative<Int8 Function(Int8, Int8)>("ffi.addInt8")
external int addInt8(int a, int b);
We generate a Wasm import using Wasm ABI types according to emscripten
calling conventions:
@pragma('wasm:import', 'ffi.addInt8')
external static WasmI32 addInt8_$import(WasmI32 a, WasmI32 b);
and convert the original member (`addInt8()`) to a wrapper function that
calls the Wasm import, converting the arguments and return values to
Dart types:
static int addInt8(int a, int b) {
return WasmI32.toIntSigned(
addInt8_$import(
WasmI32::int8FromInt(a),
WasmI32::int8FromInt(b),
));
}
Build, test, and CI changes:
- Test runner now uses `// SharedObjects=...` lines in dart2wasm tests
to pass extra Wasm modules to d8 command used to run the tests.
Support for `// SharedObjects=...` lines were already used in
native/AOT FFI tests, not added in this CL. We just start to use those
lines in dart2wasm tests.
- dart2wasm gn file updated with a target "test_wasm_modules" that
builds FFI test Wasm modules to Wasm using emcc (emscripten C
compiler).
- CI dart2wasm_hostasserts configuration updated to copy the Wasm files
generated by the "test_wasm_modules" target to the shards.
TEST=tests/web/wasm/ffi_native_test
Change-Id: I6527fe4e2ca2b582e16d84fee244e9cbe6dee307
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/252822
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Ömer Ağacan <omersa@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Aske Simon Christensen <askesc@google.com>
Dart
A client-optimized language for fast apps on any platform
Dart is:
-
Optimized for UI: Develop with a programming language specialized around the needs of user interface creation.
-
Productive: Make changes iteratively: use hot reload to see the result instantly in your running app.
-
Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web.
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).
License & patents
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See LICENSE and PATENT_GRANT.
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There are more documents on our wiki.
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