bool
Instance::callExport(JSContext* cx, uint32_t funcIndex, CallArgs args)
{
if (!cx->compartment()->wasm.ensureProfilingState(cx))
return false;
const FuncExport& func = metadata().lookupFuncExport(funcIndex);
// The calling convention for an external call into wasm is to pass an
// array of 16-byte values where each value contains either a coerced int32
// (in the low word), a double value (in the low dword) or a SIMD vector
// value, with the coercions specified by the wasm signature. The external
// entry point unpacks this array into the system-ABI-specified registers
// and stack memory and then calls into the internal entry point. The return
// value is stored in the first element of the array (which, therefore, must
// have length >= 1).
Vector<ExportArg, 8> exportArgs(cx);
if (!exportArgs.resize(Max<size_t>(1, func.sig().args().length())))
return false;
RootedValue v(cx);
for (unsigned i = 0; i < func.sig().args().length(); ++i) {
v = i < args.length() ? args[i] : UndefinedValue();
switch (func.sig().arg(i)) {
case ValType::I32:
if (!ToInt32(cx, v, (int32_t*)&exportArgs[i]))
return false;
break;
case ValType::I64:
if (!JitOptions.wasmTestMode) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_WASM_BAD_I64);
return false;
}
if (!ReadI64Object(cx, v, (int64_t*)&exportArgs[i]))
return false;
break;
case ValType::F32:
if (JitOptions.wasmTestMode && v.isObject()) {
if (!ReadCustomFloat32NaNObject(cx, v, (float*)&exportArgs[i]))
return false;
break;
}
if (!RoundFloat32(cx, v, (float*)&exportArgs[i]))
return false;
break;
case ValType::F64:
if (JitOptions.wasmTestMode && v.isObject()) {
if (!ReadCustomDoubleNaNObject(cx, v, (double*)&exportArgs[i]))
return false;
break;
}
if (!ToNumber(cx, v, (double*)&exportArgs[i]))
return false;
break;
case ValType::I8x16: {
SimdConstant simd;
if (!ToSimdConstant<Int8x16>(cx, v, &simd))
return false;
memcpy(&exportArgs[i], simd.asInt8x16(), Simd128DataSize);
break;
}
case ValType::I16x8: {
SimdConstant simd;
if (!ToSimdConstant<Int16x8>(cx, v, &simd))
return false;
memcpy(&exportArgs[i], simd.asInt16x8(), Simd128DataSize);
break;
}
case ValType::I32x4: {
SimdConstant simd;
if (!ToSimdConstant<Int32x4>(cx, v, &simd))
return false;
memcpy(&exportArgs[i], simd.asInt32x4(), Simd128DataSize);
break;
}
case ValType::F32x4: {
SimdConstant simd;
if (!ToSimdConstant<Float32x4>(cx, v, &simd))
return false;
memcpy(&exportArgs[i], simd.asFloat32x4(), Simd128DataSize);
break;
}
case ValType::B8x16: {
SimdConstant simd;
if (!ToSimdConstant<Bool8x16>(cx, v, &simd))
return false;
// Bool8x16 uses the same representation as Int8x16.
memcpy(&exportArgs[i], simd.asInt8x16(), Simd128DataSize);
break;
}
case ValType::B16x8: {
SimdConstant simd;
if (!ToSimdConstant<Bool16x8>(cx, v, &simd))
return false;
// Bool16x8 uses the same representation as Int16x8.
memcpy(&exportArgs[i], simd.asInt16x8(), Simd128DataSize);
break;
}
case ValType::B32x4: {
SimdConstant simd;
if (!ToSimdConstant<Bool32x4>(cx, v, &simd))
return false;
// Bool32x4 uses the same representation as Int32x4.
memcpy(&exportArgs[i], simd.asInt32x4(), Simd128DataSize);
break;
}
case ValType::Limit:
MOZ_CRASH("Limit");
}
}
{
// Push a WasmActivation to describe the wasm frames we're about to push
// when running this module. Additionally, push a JitActivation so that
// the optimized wasm-to-Ion FFI call path (which we want to be very
// fast) can avoid doing so. The JitActivation is marked as inactive so
// stack iteration will skip over it.
WasmActivation activation(cx);
JitActivation jitActivation(cx, /* active */ false);
// Call the per-exported-function trampoline created by GenerateEntry.
auto funcPtr = JS_DATA_TO_FUNC_PTR(ExportFuncPtr, codeBase() + func.entryOffset());
if (!CALL_GENERATED_2(funcPtr, exportArgs.begin(), &tlsData_))
return false;
}
if (args.isConstructing()) {
// By spec, when a function is called as a constructor and this function
// returns a primary type, which is the case for all wasm exported
// functions, the returned value is discarded and an empty object is
// returned instead.
PlainObject* obj = NewBuiltinClassInstance<PlainObject>(cx);
if (!obj)
return false;
args.rval().set(ObjectValue(*obj));
return true;
}
void* retAddr = &exportArgs[0];
JSObject* retObj = nullptr;
switch (func.sig().ret()) {
case ExprType::Void:
args.rval().set(UndefinedValue());
break;
case ExprType::I32:
args.rval().set(Int32Value(*(int32_t*)retAddr));
break;
case ExprType::I64:
if (!JitOptions.wasmTestMode) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_WASM_BAD_I64);
return false;
}
retObj = CreateI64Object(cx, *(int64_t*)retAddr);
if (!retObj)
return false;
break;
case ExprType::F32:
if (JitOptions.wasmTestMode && IsNaN(*(float*)retAddr)) {
retObj = CreateCustomNaNObject(cx, (float*)retAddr);
if (!retObj)
return false;
break;
}
args.rval().set(NumberValue(*(float*)retAddr));
break;
case ExprType::F64:
if (JitOptions.wasmTestMode && IsNaN(*(double*)retAddr)) {
retObj = CreateCustomNaNObject(cx, (double*)retAddr);
if (!retObj)
return false;
break;
}
args.rval().set(NumberValue(*(double*)retAddr));
break;
case ExprType::I8x16:
retObj = CreateSimd<Int8x16>(cx, (int8_t*)retAddr);
if (!retObj)
return false;
break;
case ExprType::I16x8:
retObj = CreateSimd<Int16x8>(cx, (int16_t*)retAddr);
if (!retObj)
return false;
break;
case ExprType::I32x4:
retObj = CreateSimd<Int32x4>(cx, (int32_t*)retAddr);
if (!retObj)
return false;
break;
case ExprType::F32x4:
retObj = CreateSimd<Float32x4>(cx, (float*)retAddr);
if (!retObj)
return false;
break;
case ExprType::B8x16:
retObj = CreateSimd<Bool8x16>(cx, (int8_t*)retAddr);
if (!retObj)
return false;
break;
case ExprType::B16x8:
retObj = CreateSimd<Bool16x8>(cx, (int16_t*)retAddr);
if (!retObj)
return false;
break;
case ExprType::B32x4:
retObj = CreateSimd<Bool32x4>(cx, (int32_t*)retAddr);
if (!retObj)
return false;
break;
case ExprType::Limit:
MOZ_CRASH("Limit");
}
if (retObj)
args.rval().set(ObjectValue(*retObj));
return true;
}
