fune/toolkit/components/uniffi-js/UniFFIPointer.cpp
Ben Dean-Kawamura 1cf71b7095 Bug 1766045 - Initial work for UniFFI JS bindings r=nika
Generate the C++ and JS code to handle UniFFI bindings.  The WebIDL code
is completely static and doesn't need to be generated.

There's support for both synchronus and async functions, but we haven't
decided the how we want this to be configured.  In practice, almost all
functions will need to be async, so for now we're just forcing all
functions to be.

The `uniffi-bindgen-gecko-js` crate builds the binary that generates the
bindings.  This binary needs to be fed a list of UDL files, the path of
the .cpp file to generate, and the directory to generate .jsm files in
(and also all of those arguments again, but for the test fixtures).
This is quiet a horrible UI, but it's going to be wrapped in a mach
command.

The `uniffi-js` directory contains shared C++ code for
`uniffi-bindgen-gecko-js`.  As much as possible we tried to put the
functionality here and have the generated code simply forward function
calls here.

Still Todo:
  - CallbackInterfaces
  - Custom and external types
  - Datetime and TimeInterval

Differential Revision: https://phabricator.services.mozilla.com/D144472
2022-08-03 18:59:35 +00:00

112 lines
4 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsPrintfCString.h"
#include "mozilla/EndianUtils.h"
#include "mozilla/dom/UniFFIPointer.h"
#include "mozilla/dom/UniFFIBinding.h"
#include "mozilla/Logging.h"
#include "UniFFIRust.h"
static mozilla::LazyLogModule sUniFFIPointerLogger("uniffi_logger");
namespace mozilla::dom {
using uniffi::RUST_CALL_SUCCESS;
using uniffi::RustCallStatus;
using uniffi::UniFFIPointerType;
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(UniFFIPointer)
NS_IMPL_CYCLE_COLLECTING_ADDREF(UniFFIPointer)
NS_IMPL_CYCLE_COLLECTING_RELEASE(UniFFIPointer)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(UniFFIPointer)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
// Static function
already_AddRefed<UniFFIPointer> UniFFIPointer::Create(
void* aPtr, const UniFFIPointerType* aType) {
RefPtr<UniFFIPointer> uniFFIPointer = new UniFFIPointer(aPtr, aType);
return uniFFIPointer.forget();
}
already_AddRefed<UniFFIPointer> UniFFIPointer::Read(
const ArrayBuffer& aArrayBuff, uint32_t aPosition,
const UniFFIPointerType* aType, ErrorResult& aError) {
MOZ_LOG(sUniFFIPointerLogger, LogLevel::Info,
("[UniFFI] Reading Pointer from buffer"));
aArrayBuff.ComputeState();
CheckedUint32 position = aPosition;
CheckedUint32 end = position + 8;
if (!end.isValid() || end.value() > aArrayBuff.Length()) {
aError.ThrowRangeError("position is out of range");
return nullptr;
}
// in Rust and Write(), a pointer is converted to a void* then written as u64
// BigEndian we do the reverse here
uint8_t* data_ptr = aArrayBuff.Data() +
aPosition; // Pointer arithmetic, move by position bytes
void* ptr = (void*)mozilla::BigEndian::readUint64(data_ptr);
return UniFFIPointer::Create(ptr, aType);
}
void UniFFIPointer::Write(const ArrayBuffer& aArrayBuff, uint32_t aPosition,
const UniFFIPointerType* aType,
ErrorResult& aError) const {
if (!this->IsSamePtrType(aType)) {
aError.ThrowUnknownError(nsPrintfCString(
"Attempt to write pointer with wrong type: %s (expected: %s)",
aType->typeName.get(), this->mType->typeName.get()));
return;
}
MOZ_LOG(sUniFFIPointerLogger, LogLevel::Info,
("[UniFFI] Writing Pointer to buffer"));
aArrayBuff.ComputeState();
CheckedUint32 position = aPosition;
CheckedUint32 end = position + 8;
if (!end.isValid() || end.value() > aArrayBuff.Length()) {
aError.ThrowRangeError("position is out of range");
return;
}
// in Rust and Read(), a u64 is read as BigEndian and then converted to a
// pointer we do the reverse here
uint8_t* data_ptr = aArrayBuff.Data() +
aPosition; // Pointer arithmetic, move by position bytes
mozilla::BigEndian::writeUint64(data_ptr, (uint64_t)GetPtr());
}
UniFFIPointer::UniFFIPointer(void* aPtr, const UniFFIPointerType* aType) {
mPtr = aPtr;
mType = aType;
}
JSObject* UniFFIPointer::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return dom::UniFFIPointer_Binding::Wrap(aCx, this, aGivenProto);
}
void* UniFFIPointer::GetPtr() const {
MOZ_LOG(sUniFFIPointerLogger, LogLevel::Info,
("[UniFFI] Getting raw pointer"));
return this->mPtr;
}
bool UniFFIPointer::IsSamePtrType(const UniFFIPointerType* aType) const {
return this->mType == aType;
}
UniFFIPointer::~UniFFIPointer() {
MOZ_LOG(sUniFFIPointerLogger, LogLevel::Info,
("[UniFFI] Destroying pointer"));
RustCallStatus status{};
this->mType->destructor(this->mPtr, &status);
MOZ_DIAGNOSTIC_ASSERT(status.code == RUST_CALL_SUCCESS,
"UniFFI destructor call returned a non-success result");
}
} // namespace mozilla::dom