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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
*
* Copyright 2016 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "wasm/WasmPI.h"
#include "builtin/Promise.h"
#include "jit/arm/Simulator-arm.h"
#include "jit/MIRGenerator.h"
#include "js/CallAndConstruct.h"
#include "vm/Iteration.h"
#include "vm/JSContext.h"
#include "vm/JSObject.h"
#include "vm/NativeObject.h"
#include "vm/PromiseObject.h"
#include "wasm/WasmConstants.h"
#include "wasm/WasmContext.h"
#include "wasm/WasmFeatures.h"
#include "wasm/WasmGenerator.h"
#include "wasm/WasmValidate.h"
#include "vm/JSObject-inl.h"
#include "wasm/WasmGcObject-inl.h"
#include "wasm/WasmInstance-inl.h"
#ifdef JS_CODEGEN_ARM64
# include "jit/arm64/vixl/Simulator-vixl.h"
#endif
#ifdef XP_WIN
# include "util/WindowsWrapper.h"
#endif
using namespace js;
using namespace js::jit;
#ifdef ENABLE_WASM_JSPI
namespace js::wasm {
SuspenderObjectData::SuspenderObjectData(void* stackMemory)
: stackMemory_(stackMemory),
suspendableFP_(nullptr),
suspendableSP_(static_cast<uint8_t*>(stackMemory) +
SuspendableStackPlusRedZoneSize),
state_(SuspenderState::Initial) {}
void SuspenderObjectData::releaseStackMemory() {
js_free(stackMemory_);
stackMemory_ = nullptr;
}
# if defined(_WIN32)
// On WIN64, the Thread Information Block stack limits has to be modified to
// avoid failures on SP checks.
void SuspenderObjectData::updateTIBStackFields() {
_NT_TIB* tib = reinterpret_cast<_NT_TIB*>(::NtCurrentTeb());
savedStackBase_ = tib->StackBase;
savedStackLimit_ = tib->StackLimit;
uintptr_t stack_limit = (uintptr_t)stackMemory_;
uintptr_t stack_base = stack_limit + SuspendableStackPlusRedZoneSize;
tib->StackBase = (void*)stack_base;
tib->StackLimit = (void*)stack_limit;
}
void SuspenderObjectData::restoreTIBStackFields() {
_NT_TIB* tib = reinterpret_cast<_NT_TIB*>(::NtCurrentTeb());
tib->StackBase = savedStackBase_;
tib->StackLimit = savedStackLimit_;
}
# endif
# ifdef JS_SIMULATOR_ARM64
void SuspenderObjectData::switchSimulatorToMain() {
auto* sim = Simulator::Current();
suspendableSP_ = (void*)sim->xreg(Registers::sp, vixl::Reg31IsStackPointer);
suspendableFP_ = (void*)sim->xreg(Registers::fp);
sim->set_xreg(Registers::sp, (int64_t)mainSP_, vixl::Debugger::LogRegWrites,
vixl::Reg31IsStackPointer);
sim->set_xreg(Registers::fp, (int64_t)mainFP_);
}
void SuspenderObjectData::switchSimulatorToSuspendable() {
auto* sim = Simulator::Current();
mainSP_ = (void*)sim->xreg(Registers::sp, vixl::Reg31IsStackPointer);
mainFP_ = (void*)sim->xreg(Registers::fp);
sim->set_xreg(Registers::sp, (int64_t)suspendableSP_,
vixl::Debugger::LogRegWrites, vixl::Reg31IsStackPointer);
sim->set_xreg(Registers::fp, (int64_t)suspendableFP_);
}
# endif
# ifdef JS_SIMULATOR_ARM
void SuspenderObjectData::switchSimulatorToMain() {
suspendableSP_ = (void*)Simulator::Current()->get_register(Simulator::sp);
suspendableFP_ = (void*)Simulator::Current()->get_register(Simulator::fp);
Simulator::Current()->set_register(Simulator::sp, (int)mainSP_);
Simulator::Current()->set_register(Simulator::fp, (int)mainFP_);
}
void SuspenderObjectData::switchSimulatorToSuspendable() {
mainSP_ = (void*)Simulator::Current()->get_register(Simulator::sp);
mainFP_ = (void*)Simulator::Current()->get_register(Simulator::fp);
Simulator::Current()->set_register(Simulator::sp, (int)suspendableSP_);
Simulator::Current()->set_register(Simulator::fp, (int)suspendableFP_);
}
# endif
// Slots that used in various JSFunctionExtended below.
const size_t SUSPENDER_SLOT = 0;
const size_t WRAPPED_FN_SLOT = 1;
const size_t CONTINUE_ON_SUSPENDABLE_SLOT = 1;
SuspenderContext::SuspenderContext()
: activeSuspender_(nullptr), suspendedStacks_() {}
SuspenderContext::~SuspenderContext() {
MOZ_ASSERT(activeSuspender_ == nullptr);
MOZ_ASSERT(suspendedStacks_.isEmpty());
}
SuspenderObject* SuspenderContext::activeSuspender() {
return activeSuspender_;
}
void SuspenderContext::setActiveSuspender(SuspenderObject* obj) {
activeSuspender_.set(obj);
}
void SuspenderContext::trace(JSTracer* trc) {
if (activeSuspender_) {
TraceEdge(trc, &activeSuspender_, "suspender");
}
}
void SuspenderContext::traceRoots(JSTracer* trc) {
for (const SuspenderObjectData& data : suspendedStacks_) {
void* startFP = data.suspendableFP();
void* returnAddress = data.suspendedReturnAddress();
void* exitFP = data.suspendableExitFP();
MOZ_ASSERT(startFP != exitFP);
WasmFrameIter iter(static_cast<FrameWithInstances*>(startFP),
returnAddress);
MOZ_ASSERT(iter.stackSwitched());
uintptr_t highestByteVisitedInPrevWasmFrame = 0;
while (true) {
MOZ_ASSERT(!iter.done());
uint8_t* nextPC = iter.resumePCinCurrentFrame();
Instance* instance = iter.instance();
TraceInstanceEdge(trc, instance, "WasmFrameIter instance");
highestByteVisitedInPrevWasmFrame = instance->traceFrame(
trc, iter, nextPC, highestByteVisitedInPrevWasmFrame);
if (iter.frame() == exitFP) {
break;
}
++iter;
if (iter.stackSwitched()) {
highestByteVisitedInPrevWasmFrame = 0;
}
}
}
}
static_assert(JS_STACK_GROWTH_DIRECTION < 0,
"JS-PI implemented only for native stacks that grows towards 0");
static void DecrementSuspendableStacksCount(JSContext* cx) {
for (;;) {
uint32_t currentCount = cx->wasm().suspendableStacksCount;
MOZ_ASSERT(currentCount > 0);
if (cx->wasm().suspendableStacksCount.compareExchange(currentCount,
currentCount - 1)) {
break;
}
// Failed to decrement suspendableStacksCount, repeat.
}
}
class SuspenderObject : public NativeObject {
public:
static const JSClass class_;
enum { DataSlot, PromisingPromiseSlot, SuspendingPromiseSlot, SlotCount };
static SuspenderObject* create(JSContext* cx) {
for (;;) {
uint32_t currentCount = cx->wasm().suspendableStacksCount;
if (currentCount >= SuspendableStacksMaxCount) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_JSPI_SUSPENDER_LIMIT);
return nullptr;
}
if (cx->wasm().suspendableStacksCount.compareExchange(currentCount,
currentCount + 1)) {
break;
}
// Failed to increment suspendableStacksCount, repeat.
}
Rooted<SuspenderObject*> suspender(
cx, NewBuiltinClassInstance<SuspenderObject>(cx));
if (!suspender) {
DecrementSuspendableStacksCount(cx);
return nullptr;
}
void* stackMemory = js_malloc(SuspendableStackPlusRedZoneSize);
if (!stackMemory) {
DecrementSuspendableStacksCount(cx);
ReportOutOfMemory(cx);
return nullptr;
}
SuspenderObjectData* data = js_new<SuspenderObjectData>(stackMemory);
if (!data) {
js_free(stackMemory);
DecrementSuspendableStacksCount(cx);
ReportOutOfMemory(cx);
return nullptr;
}
MOZ_RELEASE_ASSERT(data->state() != SuspenderState::Moribund);
suspender->initReservedSlot(DataSlot, PrivateValue(data));
suspender->initReservedSlot(PromisingPromiseSlot, NullValue());
suspender->initReservedSlot(SuspendingPromiseSlot, NullValue());
return suspender;
}
PromiseObject* promisingPromise() const {
return &getReservedSlot(PromisingPromiseSlot)
.toObject()
.as<PromiseObject>();
}
void setPromisingPromise(Handle<PromiseObject*> promise) {
setReservedSlot(PromisingPromiseSlot, ObjectOrNullValue(promise));
}
PromiseObject* suspendingPromise() const {
return &getReservedSlot(SuspendingPromiseSlot)
.toObject()
.as<PromiseObject>();
}
void setSuspendingPromise(Handle<PromiseObject*> promise) {
setReservedSlot(SuspendingPromiseSlot, ObjectOrNullValue(promise));
}
JS::NativeStackLimit getStackMemoryLimit() {
return JS::NativeStackLimit(data()->stackMemory()) + SuspendableRedZoneSize;
}
SuspenderState state() { return data()->state(); }
inline bool hasData() { return !getReservedSlot(DataSlot).isUndefined(); }
inline SuspenderObjectData* data() {
return static_cast<SuspenderObjectData*>(
getReservedSlot(DataSlot).toPrivate());
}
void setMoribund(JSContext* cx);
void setActive(JSContext* cx);
void setSuspended(JSContext* cx);
void enter(JSContext* cx);
void suspend(JSContext* cx);
void resume(JSContext* cx);
void leave(JSContext* cx);
private:
static const JSClassOps classOps_;
static void finalize(JS::GCContext* gcx, JSObject* obj);
};
static_assert(SuspenderObjectDataSlot == SuspenderObject::DataSlot);
const JSClass SuspenderObject::class_ = {
"SuspenderObject",
JSCLASS_HAS_RESERVED_SLOTS(SlotCount) | JSCLASS_BACKGROUND_FINALIZE,
&SuspenderObject::classOps_,
};
const JSClassOps SuspenderObject::classOps_ = {
nullptr, // addProperty
nullptr, // delProperty
nullptr, // enumerate
nullptr, // newEnumerate
nullptr, // resolve
nullptr, // mayResolve
finalize, // finalize
nullptr, // call
nullptr, // construct
nullptr, // trace
};
/* static */
void SuspenderObject::finalize(JS::GCContext* gcx, JSObject* obj) {
SuspenderObject& suspender = obj->as<SuspenderObject>();
if (!suspender.hasData()) {
return;
}
SuspenderObjectData* data = suspender.data();
MOZ_RELEASE_ASSERT(data->state() == SuspenderState::Moribund);
MOZ_RELEASE_ASSERT(!data->stackMemory());
js_free(data);
}
void SuspenderObject::setMoribund(JSContext* cx) {
MOZ_ASSERT(state() == SuspenderState::Active);
ResetInstanceStackLimits(cx);
# if defined(_WIN32)
data()->restoreTIBStackFields();
# endif
SuspenderObjectData* data = this->data();
data->setState(SuspenderState::Moribund);
data->releaseStackMemory();
DecrementSuspendableStacksCount(cx);
MOZ_ASSERT(
!cx->wasm().promiseIntegration.suspendedStacks_.ElementProbablyInList(
data));
}
void SuspenderObject::setActive(JSContext* cx) {
data()->setState(SuspenderState::Active);
UpdateInstanceStackLimitsForSuspendableStack(cx, getStackMemoryLimit());
# if defined(_WIN32)
data()->updateTIBStackFields();
# endif
}
void SuspenderObject::setSuspended(JSContext* cx) {
data()->setState(SuspenderState::Suspended);
ResetInstanceStackLimits(cx);
# if defined(_WIN32)
data()->restoreTIBStackFields();
# endif
}
void SuspenderObject::enter(JSContext* cx) {
MOZ_ASSERT(state() == SuspenderState::Initial);
cx->wasm().promiseIntegration.setActiveSuspender(this);
setActive(cx);
}
void SuspenderObject::suspend(JSContext* cx) {
MOZ_ASSERT(state() == SuspenderState::Active);
setSuspended(cx);
cx->wasm().promiseIntegration.suspendedStacks_.pushFront(data());
cx->wasm().promiseIntegration.setActiveSuspender(nullptr);
}
void SuspenderObject::resume(JSContext* cx) {
MOZ_ASSERT(state() == SuspenderState::Suspended);
cx->wasm().promiseIntegration.setActiveSuspender(this);
setActive(cx);
cx->wasm().promiseIntegration.suspendedStacks_.remove(data());
}
void SuspenderObject::leave(JSContext* cx) {
cx->wasm().promiseIntegration.setActiveSuspender(nullptr);
// We are exiting alternative stack if state is active,
// otherwise the stack was just suspended.
switch (state()) {
case SuspenderState::Active:
setMoribund(cx);
break;
case SuspenderState::Suspended:
break;
case SuspenderState::Initial:
case SuspenderState::Moribund:
MOZ_CRASH();
}
}
bool ParseSuspendingPromisingString(JSContext* cx, HandleValue val,
SuspenderArgPosition& result) {
if (val.isNullOrUndefined()) {
result = SuspenderArgPosition::None;
return true;
}
RootedString str(cx, ToString(cx, val));
if (!str) {
return false;
}
Rooted<JSLinearString*> linear(cx, str->ensureLinear(cx));
if (!linear) {
return false;
}
if (StringEqualsLiteral(linear, "first")) {
result = SuspenderArgPosition::First;
} else if (StringEqualsLiteral(linear, "last")) {
result = SuspenderArgPosition::Last;
} else {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_JSPI_ARG_POSITION);
return false;
}
return true;
}
using CallImportData = Instance::WasmJSPICallImportData;
/*static*/
bool CallImportData::Call(CallImportData* data) {
Instance* instance = data->instance;
JSContext* cx = instance->cx();
return instance->callImport(cx, data->funcImportIndex, data->argc,
data->argv);
}
bool CallImportOnMainThread(JSContext* cx, Instance* instance,
int32_t funcImportIndex, int32_t argc,
uint64_t* argv) {
CallImportData data = {instance, funcImportIndex, argc, argv};
Rooted<SuspenderObject*> suspender(
cx, cx->wasm().promiseIntegration.activeSuspender());
SuspenderObjectData* stacks = suspender->data();
cx->wasm().promiseIntegration.setActiveSuspender(nullptr);
MOZ_ASSERT(suspender->state() == SuspenderState::Active);
suspender->setSuspended(cx);
# ifdef JS_SIMULATOR
# if defined(JS_SIMULATOR_ARM64) || defined(JS_SIMULATOR_ARM)
// The simulator is using its own stack, however switching is needed for
// virtual registers.
stacks->switchSimulatorToMain();
bool res = CallImportData::Call(&data);
stacks->switchSimulatorToSuspendable();
# else
# error "not supported"
# endif
# else
// The platform specific code below inserts offsets as strings into inline
// assembly. CHECK_OFFSETS verifies the specified literals in macros below.
# define CHECK_OFFSETS(MAIN_FP_OFFSET, MAIN_SP_OFFSET, \
SUSPENDABLE_FP_OFFSET, SUSPENDABLE_SP_OFFSET) \
static_assert( \
(MAIN_FP_OFFSET) == SuspenderObjectData::offsetOfMainFP() && \
(MAIN_SP_OFFSET) == SuspenderObjectData::offsetOfMainSP() && \
(SUSPENDABLE_FP_OFFSET) == \
SuspenderObjectData::offsetOfSuspendableFP() && \
(SUSPENDABLE_SP_OFFSET) == \
SuspenderObjectData::offsetOfSuspendableSP());
// The following assembly code temporarily switches FP/SP pointers to be on
// main stack, while maintaining frames linking. After
// `CallImportData::Call` execution suspendable stack FP/SP will be restored.
//
// Because the assembly sequences contain a call, the trashed-register list
// must contain all the caller saved registers. They must also contain "cc"
// and "memory" since both of those state elements could be modified by the
// call. They also need a "volatile" qualifier to ensure that the they don't
// get optimised out or otherwise messed with by clang/gcc.
//
// `Registers::VolatileMask` (in the assembler complex) is useful in that it
// lists the caller-saved registers.
uintptr_t res;
// clang-format off
#if defined(_M_ARM64) || defined(__aarch64__)
# define CALLER_SAVED_REGS \
"x0", "x1", "x2", "x3","x4", "x5", "x6", "x7", "x8", "x9", "x10", \
"x11", "x12", "x13", "x14", "x15", "x16", "x17", /* "x18", */ \
"x19", "x20", /* it's unclear who saves these two, so be safe */ \
/* claim that all the vector regs are caller-saved, for safety */ \
"v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v8", "v9", "v10", \
"v11", "v12", "v13", "v14", "v15", "v16", "v17", "v18", "v19", \
"v20", "v21", "v22", "v23", "v24", "v25", "v26", "v27", "v28", \
"v29", "v30", "v31"
# define INLINED_ASM(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP) \
CHECK_OFFSETS(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP); \
asm volatile( \
"\n mov x0, %1" \
"\n mov x27, sp " \
"\n str x29, [x0, #" #SUSPENDABLE_FP "] " \
"\n str x27, [x0, #" #SUSPENDABLE_SP "] " \
\
"\n ldr x29, [x0, #" #MAIN_FP "] " \
"\n ldr x27, [x0, #" #MAIN_SP "] " \
"\n mov sp, x27 " \
\
"\n stp x0, x27, [sp, #-16]! " \
\
"\n mov x0, %3" \
"\n blr %2 " \
\
"\n ldp x3, x27, [sp], #16 " \
\
"\n mov x27, sp " \
"\n str x29, [x3, #" #MAIN_FP "] " \
"\n str x27, [x3, #" #MAIN_SP "] " \
\
"\n ldr x29, [x3, #" #SUSPENDABLE_FP "] " \
"\n ldr x27, [x3, #" #SUSPENDABLE_SP "] " \
"\n mov sp, x27 " \
"\n mov %0, x0" \
: "=r"(res) \
: "r"(stacks), "r"(CallImportData::Call), "r"(&data) \
: "x0", "x3", "x27", CALLER_SAVED_REGS, "cc", "memory")
INLINED_ASM(24, 32, 40, 48);
# elif defined(_WIN64) && defined(_M_X64)
# define INLINED_ASM(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP) \
CHECK_OFFSETS(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP); \
asm("\n mov %1, %%rcx" \
"\n mov %%rbp, " #SUSPENDABLE_FP "(%%rcx)" \
"\n mov %%rsp, " #SUSPENDABLE_SP "(%%rcx)" \
\
"\n mov " #MAIN_FP "(%%rcx), %%rbp" \
"\n mov " #MAIN_SP "(%%rcx), %%rsp" \
\
"\n push %%rcx" \
"\n push %%rdx" \
\
"\n mov %3, %%rcx" \
"\n call *%2" \
\
"\n pop %%rdx" \
"\n pop %%rcx" \
\
"\n mov %%rbp, " #MAIN_FP "(%%rcx)" \
"\n mov %%rsp, " #MAIN_SP "(%%rcx)" \
\
"\n mov " #SUSPENDABLE_FP "(%%rcx), %%rbp" \
"\n mov " #SUSPENDABLE_SP "(%%rcx), %%rsp" \
\
"\n movq %%rax, %0" \
: "=r"(res) \
: "r"(stacks), "r"(CallImportData::Call), "r"(&data) \
: "rcx", "rax")
INLINED_ASM(24, 32, 40, 48);
# elif defined(__x86_64__)
# define INLINED_ASM(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP) \
CHECK_OFFSETS(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP); \
asm("\n mov %1, %%rdi" \
"\n mov %%rbp, " #SUSPENDABLE_FP "(%%rdi)" \
"\n mov %%rsp, " #SUSPENDABLE_SP "(%%rdi)" \
\
"\n mov " #MAIN_FP "(%%rdi), %%rbp" \
"\n mov " #MAIN_SP "(%%rdi), %%rsp" \
\
"\n push %%rdi" \
"\n push %%rdx" \
\
"\n mov %3, %%rdi" \
"\n call *%2" \
\
"\n pop %%rdx" \
"\n pop %%rdi" \
\
"\n mov %%rbp, " #MAIN_FP "(%%rdi)" \
"\n mov %%rsp, " #MAIN_SP "(%%rdi)" \
\
"\n mov " #SUSPENDABLE_FP "(%%rdi), %%rbp" \
"\n mov " #SUSPENDABLE_SP "(%%rdi), %%rsp" \
\
"\n movq %%rax, %0" \
: "=r"(res) \
: "r"(stacks), "r"(CallImportData::Call), "r"(&data) \
: "rdi", "rax")
INLINED_ASM(24, 32, 40, 48);
# elif defined(__i386__) || defined(_M_IX86)
# define CALLER_SAVED_REGS "eax", "ecx", "edx"
# define INLINED_ASM(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP) \
CHECK_OFFSETS(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP); \
asm("\n mov %1, %%edx" \
"\n mov %%ebp, " #SUSPENDABLE_FP "(%%edx)" \
"\n mov %%esp, " #SUSPENDABLE_SP "(%%edx)" \
\
"\n mov " #MAIN_FP "(%%edx), %%ebp" \
"\n mov " #MAIN_SP "(%%edx), %%esp" \
\
"\n push %%edx" \
"\n sub $8, %%esp" \
"\n push %3" \
"\n call *%2" \
"\n add $12, %%esp" \
"\n pop %%edx" \
\
"\n mov %%ebp, " #MAIN_FP "(%%edx)" \
"\n mov %%esp, " #MAIN_SP "(%%edx)" \
\
"\n mov " #SUSPENDABLE_FP "(%%edx), %%ebp" \
"\n mov " #SUSPENDABLE_SP "(%%edx), %%esp" \
\
"\n mov %%eax, %0" \
: "=r"(res) \
: "r"(stacks), "r"(CallImportData::Call), "r"(&data) \
: CALLER_SAVED_REGS)
INLINED_ASM(12, 16, 20, 24);
# elif defined(__arm__)
# define INLINED_ASM(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP) \
CHECK_OFFSETS(MAIN_FP, MAIN_SP, SUSPENDABLE_FP, SUSPENDABLE_SP); \
asm("\n mov r0, %1" \
"\n mov r1, sp" \
"\n str r11, [r0, #" #SUSPENDABLE_FP "]" \
"\n str r1, [r0, #" #SUSPENDABLE_SP "]" \
\
"\n ldr r11, [r0, #" #MAIN_FP "]" \
"\n ldr r1, [r0, #" #MAIN_SP "]" \
"\n mov sp, r1" \
\
"\n str r0, [sp, #-8]! " \
\
"\n mov r0, %3" \
"\n blx %2" \
\
"\n ldr r2, [sp], #8 " \
\
"\n mov r1, sp" \
"\n str r11, [r2, #" #MAIN_FP "]" \
"\n str r1, [r2, #" #MAIN_SP "]" \
\
"\n ldr r11, [r2, #" #SUSPENDABLE_FP "]" \
"\n ldr r1, [r2, #" #SUSPENDABLE_SP "]" \
"\n mov sp, r1" \
"\n mov %0, r0" \
: "=r"(res) \
: "r"(stacks), "r"(CallImportData::Call), "r"(&data) \
: "r0", "r1", "r2")
INLINED_ASM(12, 16, 20, 24);
# else
MOZ_CRASH("Not supported for this platform");
# endif
// clang-format on
# endif // JS_SIMULATOR
bool ok = res;
suspender->setActive(cx);
cx->wasm().promiseIntegration.setActiveSuspender(suspender);
# undef INLINED_ASM
# undef CHECK_OFFSETS
# undef CALLER_SAVED_REGS
return ok;
}
static void CleanupActiveSuspender(JSContext* cx) {
SuspenderObject* suspender = cx->wasm().promiseIntegration.activeSuspender();
MOZ_ASSERT(suspender);
cx->wasm().promiseIntegration.setActiveSuspender(nullptr);
suspender->setMoribund(cx);
}
// Suspending
// Builds a wasm module with following structure:
// (module
// (type $params (struct (field ..)*)))
// (type $results (struct (field ..)*)))
// (import "" "" (func $suspending.wrappedfn ..))
// (func $suspending.exported .. )
// (func $suspending.trampoline ..)
// (func $suspending.continue-on-suspendable ..)
// (export "" (func $suspending.exported))
// )
//
// The module provides logic for the state transitions (see the SMDOC):
// - Invoke Suspending Import via $suspending.exported
// - Suspending Function Returns a Promise via $suspending.trampoline
// - Promise Resolved transitions via $suspending.continue-on-suspendable
//
class SuspendingFunctionModuleFactory {
public:
enum TypeIdx {
ParamsTypeIndex,
ResultsTypeIndex,
};
enum FnIdx {
WrappedFnIndex,
ExportedFnIndex,
TrampolineFnIndex,
ContinueOnSuspendableFnIndex
};
private:
// Builds function that will be imported to wasm module:
// (func $suspending.exported
// (param $suspender externref)? (param ..)* (param $suspender externref)?
// (result ..)*
// (local $suspender externref)?
// (local $results (ref $results))
// ;; #if checkSuspender
// local.get $suspender
// call $builtin.check-suspender
// ;; #else
// call $builtin.current-suspender
// local.tee $suspender
// ;; #endif
// ref.func $suspending.trampoline
// local.get $i*
// stuct.new $param-type
// stack-switch SwitchToMain ;; <- (suspender,fn,data)
// local.get $suspender
// call $builtin.get-suspending-promise-result
// ref.cast $results-type
// local.set $results
// (struct.get $results (local.get $results))*
// )
bool encodeExportedFunction(CodeMetadata& codeMeta, uint32_t paramsSize,
uint32_t resultSize, uint32_t paramsOffset,
uint32_t suspenderIndex, bool checkSuspender,
RefType resultType, Bytes& bytecode) {
Encoder encoder(bytecode, *codeMeta.types);
ValTypeVector locals;
if (!checkSuspender && !locals.emplaceBack(RefType::extern_())) {
return false;
}
if (!locals.emplaceBack(resultType)) {
return false;
}
if (!EncodeLocalEntries(encoder, locals)) {
return false;
}
if (checkSuspender) {
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(suspenderIndex)) {
return false;
}
if (!encoder.writeOp(MozOp::CallBuiltinModuleFunc) ||
!encoder.writeVarU32((uint32_t)BuiltinModuleFuncId::CheckSuspender)) {
return false;
}
} else {
if (!encoder.writeOp(Op::I32Const) || !encoder.writeVarU32(0)) {
return false;
}
if (!encoder.writeOp(MozOp::CallBuiltinModuleFunc) ||
!encoder.writeVarU32(
(uint32_t)BuiltinModuleFuncId::CurrentSuspender)) {
return false;
}
if (!encoder.writeOp(Op::LocalTee) ||
!encoder.writeVarU32(suspenderIndex)) {
return false;
}
}
// Results local is located after all params and suspender.
// Adding 1 to paramSize for checkSuspender and ! cases.
int resultsIndex = paramsSize + 1;
if (!encoder.writeOp(Op::RefFunc) ||
!encoder.writeVarU32(TrampolineFnIndex)) {
return false;
}
for (uint32_t i = 0; i < paramsSize; i++) {
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(i + paramsOffset)) {
return false;
}
}
if (!encoder.writeOp(GcOp::StructNew) ||
!encoder.writeVarU32(ParamsTypeIndex)) {
return false;
}
if (!encoder.writeOp(MozOp::StackSwitch) ||
!encoder.writeVarU32(uint32_t(StackSwitchKind::SwitchToMain))) {
return false;
}
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(suspenderIndex)) {
return false;
}
if (!encoder.writeOp(MozOp::CallBuiltinModuleFunc) ||
!encoder.writeVarU32(
(uint32_t)BuiltinModuleFuncId::GetSuspendingPromiseResult)) {
return false;
}
if (!encoder.writeOp(GcOp::RefCast) ||
!encoder.writeVarU32(ResultsTypeIndex) ||
!encoder.writeOp(Op::LocalSet) || !encoder.writeVarU32(resultsIndex)) {
return false;
}
for (uint32_t i = 0; i < resultSize; i++) {
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(resultsIndex) ||
!encoder.writeOp(GcOp::StructGet) ||
!encoder.writeVarU32(ResultsTypeIndex) || !encoder.writeVarU32(i)) {
return false;
}
}
return encoder.writeOp(Op::End);
}
// Builds function that is called on main stack:
// (func $suspending.trampoline
// (param $params (ref $suspender) (ref $param-type))
// (result externref)
// local.get $suspender ;; for call $add-promise-reactions
// (struct.get $param-type $i (local.get $param))*
// call $suspending.wrappedfn
// ref.func $suspending.continue-on-suspendable
// call $builtin.add-promise-reactions
// )
// The function calls suspending import and returns into the
// $promising.exported function because that was the top function
// on the main stack.
bool encodeTrampolineFunction(CodeMetadata& codeMeta, uint32_t paramsSize,
Bytes& bytecode) {
Encoder encoder(bytecode, *codeMeta.types);
if (!EncodeLocalEntries(encoder, ValTypeVector())) {
return false;
}
const uint32_t SuspenderIndex = 0;
const uint32_t ParamsIndex = 1;
// For AddPromiseReactions call below.
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(SuspenderIndex)) {
return false;
}
for (uint32_t i = 0; i < paramsSize; i++) {
if (!encoder.writeOp(Op::LocalGet) || !encoder.writeVarU32(ParamsIndex)) {
return false;
}
if (!encoder.writeOp(GcOp::StructGet) ||
!encoder.writeVarU32(ParamsTypeIndex) || !encoder.writeVarU32(i)) {
return false;
}
}
if (!encoder.writeOp(Op::Call) || !encoder.writeVarU32(WrappedFnIndex)) {
return false;
}
if (!encoder.writeOp(Op::RefFunc) ||
!encoder.writeVarU32(ContinueOnSuspendableFnIndex)) {
return false;
}
if (!encoder.writeOp(MozOp::CallBuiltinModuleFunc) ||
!encoder.writeVarU32(
(uint32_t)BuiltinModuleFuncId::AddPromiseReactions)) {
return false;
}
return encoder.writeOp(Op::End);
}
// Builds function that is called on main stack:
// (func $suspending.continue-on-suspendable
// (param $params (ref $suspender))
// (result externref)
// local.get $suspender
// ref.null funcref
// ref.null anyref
// stack-switch ContinueOnSuspendable
// )
bool encodeContinueOnSuspendableFunction(CodeMetadata& codeMeta,
uint32_t resultsSize,
Bytes& bytecode) {
Encoder encoder(bytecode, *codeMeta.types);
if (!EncodeLocalEntries(encoder, ValTypeVector())) {
return false;
}
const uint32_t SuspenderIndex = 0;
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(SuspenderIndex)) {
return false;
}
if (!encoder.writeOp(Op::RefNull) ||
!encoder.writeValType(ValType(RefType::func()))) {
return false;
}
if (!encoder.writeOp(Op::RefNull) ||
!encoder.writeValType(ValType(RefType::any()))) {
return false;
}
if (!encoder.writeOp(MozOp::StackSwitch) ||
!encoder.writeVarU32(
uint32_t(StackSwitchKind::ContinueOnSuspendable))) {
return false;
}
return encoder.writeOp(Op::End);
}
public:
SharedModule build(JSContext* cx, HandleObject func, ValTypeVector&& params,
ValTypeVector&& results,
SuspenderArgPosition argPosition) {
FeatureOptions options;
options.isBuiltinModule = true;
options.requireGC = true;
options.requireTailCalls = true;
ScriptedCaller scriptedCaller;
SharedCompileArgs compileArgs =
CompileArgs::buildAndReport(cx, std::move(scriptedCaller), options);
if (!compileArgs) {
return nullptr;
}
MutableModuleMetadata moduleMeta = js_new<ModuleMetadata>();
if (!moduleMeta || !moduleMeta->init(*compileArgs)) {
return nullptr;
}
MutableCodeMetadata codeMeta = moduleMeta->codeMeta;
MOZ_ASSERT(IonAvailable(cx));
CompilerEnvironment compilerEnv(CompileMode::Once, Tier::Optimized,
DebugEnabled::False);
compilerEnv.computeParameters();
RefType suspenderType = RefType::extern_();
RefType promiseType = RefType::extern_();
size_t paramsSize, paramsOffset, suspenderIndex;
size_t resultsSize = results.length();
bool checkSuspender;
ValTypeVector paramsWithoutSuspender;
switch (argPosition) {
case SuspenderArgPosition::First:
paramsSize = params.length() - 1;
paramsOffset = 1;
suspenderIndex = 0;
if (!paramsWithoutSuspender.append(params.begin() + 1, params.end())) {
ReportOutOfMemory(cx);
return nullptr;
}
checkSuspender = true;
break;
case SuspenderArgPosition::Last:
paramsSize = params.length() - 1;
paramsOffset = 0;
suspenderIndex = paramsSize - 1;
if (!paramsWithoutSuspender.append(params.begin(), params.end() - 1)) {
ReportOutOfMemory(cx);
return nullptr;
}
checkSuspender = true;
break;
default:
paramsSize = params.length();
paramsOffset = 0;
suspenderIndex = paramsSize;
if (!paramsWithoutSuspender.append(params.begin(), params.end())) {
ReportOutOfMemory(cx);
return nullptr;
}
checkSuspender = false;
break;
}
ValTypeVector resultsRef;
if (!resultsRef.emplaceBack(promiseType)) {
ReportOutOfMemory(cx);
return nullptr;
}
StructType boxedParamsStruct;
if (!StructType::createImmutable(paramsWithoutSuspender,
&boxedParamsStruct)) {
ReportOutOfMemory(cx);
return nullptr;
}
MOZ_ASSERT(codeMeta->types->length() == ParamsTypeIndex);
if (!codeMeta->types->addType(std::move(boxedParamsStruct))) {
return nullptr;
}
StructType boxedResultType;
if (!StructType::createImmutable(results, &boxedResultType)) {
ReportOutOfMemory(cx);
return nullptr;
}
MOZ_ASSERT(codeMeta->types->length() == ResultsTypeIndex);
if (!codeMeta->types->addType(std::move(boxedResultType))) {
return nullptr;
}
MOZ_ASSERT(codeMeta->funcs.length() == WrappedFnIndex);
if (!moduleMeta->addDefinedFunc(std::move(paramsWithoutSuspender),
std::move(resultsRef))) {
return nullptr;
}
// Imports names are not important, declare functions above as imports.
codeMeta->numFuncImports = codeMeta->funcs.length();
// We will be looking up and using the exports function by index so
// the name doesn't matter.
MOZ_ASSERT(codeMeta->funcs.length() == ExportedFnIndex);
if (!moduleMeta->addDefinedFunc(std::move(params), std::move(results),
/*declareForRef = */ true,
mozilla::Some(CacheableName()))) {
return nullptr;
}
ValTypeVector paramsTrampoline, resultsTrampoline;
if (!paramsTrampoline.emplaceBack(suspenderType) ||
!paramsTrampoline.emplaceBack(RefType::fromTypeDef(
&(*codeMeta->types)[ParamsTypeIndex], false))) {
ReportOutOfMemory(cx);
return nullptr;
}
MOZ_ASSERT(codeMeta->funcs.length() == TrampolineFnIndex);
if (!moduleMeta->addDefinedFunc(std::move(paramsTrampoline),
std::move(resultsTrampoline),
/*declareForRef = */ true)) {
return nullptr;
}
ValTypeVector paramsContinueOnSuspendable, resultsContinueOnSuspendable;
if (!paramsContinueOnSuspendable.emplaceBack(suspenderType) ||
!paramsContinueOnSuspendable.emplaceBack(RefType::extern_())) {
ReportOutOfMemory(cx);
return nullptr;
}
MOZ_ASSERT(codeMeta->funcs.length() == ContinueOnSuspendableFnIndex);
if (!moduleMeta->addDefinedFunc(std::move(paramsContinueOnSuspendable),
std::move(resultsContinueOnSuspendable),
/*declareForRef = */ true)) {
return nullptr;
}
if (!moduleMeta->prepareForCompile(compilerEnv.mode())) {
return nullptr;
}
ModuleGenerator mg(*codeMeta, compilerEnv, compilerEnv.initialState(),
nullptr, nullptr, nullptr);
if (!mg.initializeCompleteTier()) {
return nullptr;
}
// Build functions and keep bytecodes around until the end.
Bytes bytecode;
if (!encodeExportedFunction(
*codeMeta, paramsSize, resultsSize, paramsOffset, suspenderIndex,
checkSuspender,
RefType::fromTypeDef(&(*codeMeta->types)[ResultsTypeIndex], false),
bytecode)) {
ReportOutOfMemory(cx);
return nullptr;
}
if (!mg.compileFuncDef(ExportedFnIndex, 0, bytecode.begin(),
bytecode.begin() + bytecode.length())) {
return nullptr;
}
Bytes bytecode2;
if (!encodeTrampolineFunction(*codeMeta, paramsSize, bytecode2)) {
ReportOutOfMemory(cx);
return nullptr;
}
if (!mg.compileFuncDef(TrampolineFnIndex, 0, bytecode2.begin(),
bytecode2.begin() + bytecode2.length())) {
return nullptr;
}
Bytes bytecode3;
if (!encodeContinueOnSuspendableFunction(*codeMeta, paramsSize,
bytecode3)) {
ReportOutOfMemory(cx);
return nullptr;
}
if (!mg.compileFuncDef(ContinueOnSuspendableFnIndex, 0, bytecode3.begin(),
bytecode3.begin() + bytecode3.length())) {
return nullptr;
}
if (!mg.finishFuncDefs()) {
return nullptr;
}
SharedBytes shareableBytes = js_new<ShareableBytes>();
if (!shareableBytes) {
ReportOutOfMemory(cx);
return nullptr;
}
return mg.finishModule(*shareableBytes, moduleMeta,
/*maybeCompleteTier2Listener=*/nullptr);
}
};
// Reaction on resolved/rejected suspending promise.
static bool WasmPISuspendTaskContinue(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
Rooted<JSFunction*> callee(cx, &args.callee().as<JSFunction>());
RootedValue suspender(cx, callee->getExtendedSlot(SUSPENDER_SLOT));
// Convert result of the promise into the parameters/arguments for the
// $suspending.continue-on-suspendable.
RootedFunction continueOnSuspendable(
cx, &callee->getExtendedSlot(CONTINUE_ON_SUSPENDABLE_SLOT)
.toObject()
.as<JSFunction>());
RootedValueVector argv(cx);
if (!argv.emplaceBack(suspender)) {
ReportOutOfMemory(cx);
return false;
}
MOZ_ASSERT(args.length() > 0);
if (!argv.emplaceBack(args[0])) {
ReportOutOfMemory(cx);
return false;
}
JS::Rooted<JS::Value> rval(cx);
if (Call(cx, UndefinedHandleValue, continueOnSuspendable, argv, &rval)) {
return true;
}
// The stack was unwound during exception -- time to release resources.
CleanupActiveSuspender(cx);
if (cx->isThrowingOutOfMemory()) {
return false;
}
Rooted<PromiseObject*> promise(
cx, suspender.toObject().as<SuspenderObject>().promisingPromise());
return RejectPromiseWithPendingError(cx, promise);
}
// Wraps original import to catch all exceptions and convert result to a
// promise.
// Seen as $suspending.wrappedfn in wasm.
static bool WasmPIWrapSuspendingImport(JSContext* cx, unsigned argc,
Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
Rooted<JSFunction*> callee(cx, &args.callee().as<JSFunction>());
RootedFunction originalImportFunc(
cx,
&callee->getExtendedSlot(WRAPPED_FN_SLOT).toObject().as<JSFunction>());
// Catching exceptions here.
RootedValue rval(cx);
if (Call(cx, UndefinedHandleValue, originalImportFunc, args, &rval)) {
// Convert the result to a resolved promise.
RootedObject promiseConstructor(cx, GetPromiseConstructor(cx));
RootedObject promiseObj(cx, PromiseResolve(cx, promiseConstructor, rval));
if (!promiseObj) {
return false;
}
args.rval().setObject(*promiseObj);
return true;
}
if (cx->isThrowingOutOfMemory()) {
return false;
}
// Convert failure to a rejected promise.
RootedObject promiseObject(cx, NewPromiseObject(cx, nullptr));
if (!promiseObject) {
return false;
}
args.rval().setObject(*promiseObject);
Rooted<PromiseObject*> promise(cx, &promiseObject->as<PromiseObject>());
return RejectPromiseWithPendingError(cx, promise);
}
JSFunction* WasmSuspendingFunctionCreate(JSContext* cx, HandleObject func,
ValTypeVector&& params,
ValTypeVector&& results,
SuspenderArgPosition argPosition) {
MOZ_ASSERT(IsCallable(ObjectValue(*func)) &&
!IsCrossCompartmentWrapper(func));
if (argPosition != SuspenderArgPosition::None) {
if (params.length() < 1 ||
params[argPosition == SuspenderArgPosition::Last ? params.length() - 1
: 0] !=
RefType::extern_()) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_JSPI_EXPECTED_SUSPENDER);
return nullptr;
}
}
SuspendingFunctionModuleFactory moduleFactory;
SharedModule module = moduleFactory.build(cx, func, std::move(params),
std::move(results), argPosition);
if (!module) {
return nullptr;
}
// Instantiate the module.
Rooted<ImportValues> imports(cx);
// Add $suspending.wrappedfn to imports.
RootedFunction funcWrapper(
cx, NewNativeFunction(cx, WasmPIWrapSuspendingImport, 0, nullptr,
gc::AllocKind::FUNCTION_EXTENDED, GenericObject));
if (!funcWrapper) {
return nullptr;
}
funcWrapper->initExtendedSlot(WRAPPED_FN_SLOT, ObjectValue(*func));
if (!imports.get().funcs.append(funcWrapper)) {
ReportOutOfMemory(cx);
return nullptr;
}
Rooted<WasmInstanceObject*> instance(cx);
if (!module->instantiate(cx, imports.get(), nullptr, &instance)) {
// Can also trap on invalid input function.
return nullptr;
}
// Returns the $suspending.exported function.
RootedFunction wasmFunc(cx);
if (!WasmInstanceObject::getExportedFunction(
cx, instance, SuspendingFunctionModuleFactory::ExportedFnIndex,
&wasmFunc)) {
return nullptr;
}
return wasmFunc;
}
JSFunction* WasmSuspendingFunctionCreate(JSContext* cx, HandleObject func,
const FuncType& type) {
ValTypeVector params, results;
if (!params.append(type.args().begin(), type.args().end()) ||
!results.append(type.results().begin(), type.results().end())) {
ReportOutOfMemory(cx);
return nullptr;
}
return WasmSuspendingFunctionCreate(cx, func, std::move(params),
std::move(results),
SuspenderArgPosition::None);
}
// Promising
// Builds a wasm module with following structure:
// (module
// (type $params (struct (field ..)*))
// (type $results (struct (field ..)*))
// (type $create-suspender-result (struct (field externref externref)))
// (import "" "" (func $promising.wrappedfn ..))
// (func $promising.exported .. )
// (func $promising.trampoline ..)
// (export "" (func $promising.exported))
// )
//
// The module provides logic for the Invoke Promising Import state transition
// via $promising.exported and $promising.trampoline (see the SMDOC).
//
class PromisingFunctionModuleFactory {
public:
enum TypeIdx {
ParamsTypeIndex,
ResultsTypeIndex,
};
enum FnIdx {
WrappedFnIndex,
ExportedFnIndex,
TrampolineFnIndex,
};
private:
// Builds function that will be exported for JS:
// (func $promising.exported
// (param ..)* (result externref)
// (local $suspender externref)
// call $builtin.create-suspender
// local.tee $suspender
// call $builtin.create-promising-promise ;; -> (promise)
// local.get $suspender
// ref.func $promising.trampoline
// local.get $i*
// stuct.new $param-type
// stack-switch SwitchToSuspendable ;; <- (suspender,fn,data)
// )
bool encodeExportedFunction(CodeMetadata& codeMeta, uint32_t paramsSize,
Bytes& bytecode) {
Encoder encoder(bytecode, *codeMeta.types);
ValTypeVector locals;
if (!locals.emplaceBack(RefType::extern_())) {
return false;
}
if (!EncodeLocalEntries(encoder, locals)) {
return false;
}
const uint32_t SuspenderIndex = paramsSize;
if (!encoder.writeOp(Op::I32Const) || !encoder.writeVarU32(0)) {
return false;
}
if (!encoder.writeOp(MozOp::CallBuiltinModuleFunc) ||
!encoder.writeVarU32((uint32_t)BuiltinModuleFuncId::CreateSuspender)) {
return false;
}
if (!encoder.writeOp(Op::LocalTee) ||
!encoder.writeVarU32(SuspenderIndex)) {
return false;
}
if (!encoder.writeOp(MozOp::CallBuiltinModuleFunc) ||
!encoder.writeVarU32(
(uint32_t)BuiltinModuleFuncId::CreatePromisingPromise)) {
return false;
}
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(SuspenderIndex)) {
return false;
}
if (!encoder.writeOp(Op::RefFunc) ||
!encoder.writeVarU32(TrampolineFnIndex)) {
return false;
}
for (uint32_t i = 0; i < paramsSize; i++) {
if (!encoder.writeOp(Op::LocalGet) || !encoder.writeVarU32(i)) {
return false;
}
}
if (!encoder.writeOp(GcOp::StructNew) ||
!encoder.writeVarU32(ParamsTypeIndex)) {
return false;
}
if (!encoder.writeOp(MozOp::StackSwitch) ||
!encoder.writeVarU32(uint32_t(StackSwitchKind::SwitchToSuspendable))) {
return false;
}
return encoder.writeOp(Op::End);
}
// Builds function that is called on alternative stack:
// (func $promising.trampoline
// (param $suspender externref) (param $params (ref $param-type))
// (result externref)
// local.get $suspender ;; for call $set-results
// (local.get $suspender)?
// (struct.get $param-type $i (local.get $param))*
// (local.get $suspender)?
// call $promising.wrappedfn
// struct.new $result-type
// call $builtin.set-promising-promise-results
// )
bool encodeTrampolineFunction(CodeMetadata& codeMeta, uint32_t paramsSize,
SuspenderArgPosition argPosition,
Bytes& bytecode) {
Encoder encoder(bytecode, *codeMeta.types);
if (!EncodeLocalEntries(encoder, ValTypeVector())) {
return false;
}
const uint32_t SuspenderIndex = 0;
const uint32_t ParamsIndex = 1;
// Reserved for SetResultsFnIndex call at the end
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(SuspenderIndex)) {
return false;
}
if (argPosition == SuspenderArgPosition::First) {
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(SuspenderIndex)) {
return false;
}
}
for (uint32_t i = 0; i < paramsSize; i++) {
if (!encoder.writeOp(Op::LocalGet) || !encoder.writeVarU32(ParamsIndex)) {
return false;
}
if (!encoder.writeOp(GcOp::StructGet) ||
!encoder.writeVarU32(ParamsTypeIndex) || !encoder.writeVarU32(i)) {
return false;
}
}
if (argPosition == SuspenderArgPosition::Last) {
if (!encoder.writeOp(Op::LocalGet) ||
!encoder.writeVarU32(SuspenderIndex)) {
return false;
}
}
if (!encoder.writeOp(Op::Call) || !encoder.writeVarU32(WrappedFnIndex)) {
return false;
}
if (!encoder.writeOp(GcOp::StructNew) ||
!encoder.writeVarU32(ResultsTypeIndex)) {
return false;
}