// asm.js module instantiation supplies its own buffer, but for wasm, create and
// initialize the buffer if one is requested. Either way, the buffer is wrapped
// in a WebAssembly.Memory object which is what the Instance stores.
bool
Module::instantiateMemory(JSContext* cx, MutableHandleWasmMemoryObject memory) const
{
if (!metadata_->usesMemory()) {
MOZ_ASSERT(!memory);
MOZ_ASSERT(dataSegments_.empty());
return true;
}
RootedArrayBufferObjectMaybeShared buffer(cx);
if (memory) {
buffer = &memory->buffer();
uint32_t length = buffer->byteLength();
if (length < metadata_->minMemoryLength || length > metadata_->maxMemoryLength) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_WASM_BAD_IMP_SIZE, "Memory");
return false;
}
// This can't happen except via the shell toggling signals.enabled.
if (metadata_->assumptions.usesSignal.forOOB &&
!buffer->is<SharedArrayBufferObject>() &&
!buffer->as<ArrayBufferObject>().isWasmMapped())
{
JS_ReportError(cx, "can't access same buffer with and without signals enabled");
return false;
}
} else {
buffer = ArrayBufferObject::createForWasm(cx, metadata_->minMemoryLength,
metadata_->assumptions.usesSignal.forOOB);
if (!buffer)
return false;
RootedObject proto(cx);
if (metadata_->assumptions.newFormat)
proto = &cx->global()->getPrototype(JSProto_WasmMemory).toObject();
memory.set(WasmMemoryObject::create(cx, buffer, proto));
if (!memory)
return false;
}
MOZ_ASSERT(buffer->is<SharedArrayBufferObject>() || buffer->as<ArrayBufferObject>().isWasm());
uint8_t* memoryBase = memory->buffer().dataPointerEither().unwrap(/* memcpy */);
for (const DataSegment& seg : dataSegments_)
memcpy(memoryBase + seg.memoryOffset, bytecode_->begin() + seg.bytecodeOffset, seg.length);
return true;
}
// asm.js module instantiation supplies its own buffer, but for wasm, create and
// initialize the buffer if one is requested. Either way, the buffer is wrapped
// in a WebAssembly.Memory object which is what the Instance stores.
bool
Module::instantiateMemory(JSContext* cx, MutableHandleWasmMemoryObject memory) const
{
if (!metadata_->usesMemory()) {
MOZ_ASSERT(!memory);
MOZ_ASSERT(dataSegments_.empty());
return true;
}
uint32_t declaredMin = metadata_->minMemoryLength;
Maybe<uint32_t> declaredMax = metadata_->maxMemoryLength;
if (memory) {
ArrayBufferObjectMaybeShared& buffer = memory->buffer();
MOZ_ASSERT_IF(metadata_->isAsmJS(), buffer.isPreparedForAsmJS());
MOZ_ASSERT_IF(!metadata_->isAsmJS(), buffer.as<ArrayBufferObject>().isWasm());
if (!CheckLimits(cx, declaredMin, declaredMax, buffer.byteLength(), buffer.wasmMaxSize(),
metadata_->isAsmJS(), "Memory")) {
return false;
}
} else {
MOZ_ASSERT(!metadata_->isAsmJS());
MOZ_ASSERT(metadata_->memoryUsage == MemoryUsage::Unshared);
RootedArrayBufferObjectMaybeShared buffer(cx,
ArrayBufferObject::createForWasm(cx, declaredMin, declaredMax));
if (!buffer)
return false;
RootedObject proto(cx, &cx->global()->getPrototype(JSProto_WasmMemory).toObject());
memory.set(WasmMemoryObject::create(cx, buffer, proto));
if (!memory)
return false;
}
return true;
}