/* -*- 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 2015 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
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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/WasmGenerator.h"

#include <algorithm>

#include "jit/Assembler.h"
#include "jit/JitOptions.h"
#include "js/Printf.h"
#include "threading/Thread.h"
#include "util/Memory.h"
#include "util/Text.h"
#include "vm/HelperThreads.h"
#include "vm/Time.h"
#include "wasm/WasmBaselineCompile.h"
#include "wasm/WasmCompile.h"
#include "wasm/WasmGC.h"
#include "wasm/WasmIonCompile.h"
#include "wasm/WasmStubs.h"

using namespace js;
using namespace js::jit;
using namespace js::wasm;

bool CompiledCode::swap(MacroAssembler& masm) {
  MOZ_ASSERT(bytes.empty());
  if (!masm.swapBuffer(bytes)) {
    return false;
  }

  inliningContext.swap(masm.inliningContext());
  callSites.swap(masm.callSites());
  callSiteTargets.swap(masm.callSiteTargets());
  trapSites.swap(masm.trapSites());
  symbolicAccesses.swap(masm.symbolicAccesses());
  tryNotes.swap(masm.tryNotes());
  codeRangeUnwindInfos.swap(masm.codeRangeUnwindInfos());
  callRefMetricsPatches.swap(masm.callRefMetricsPatches());
  allocSitesPatches.swap(masm.allocSitesPatches());
  codeLabels.swap(masm.codeLabels());
  return true;
}

// ****************************************************************************
// ModuleGenerator

static const unsigned GENERATOR_LIFO_DEFAULT_CHUNK_SIZE = 4 * 1024;
static const unsigned COMPILATION_LIFO_DEFAULT_CHUNK_SIZE = 64 * 1024;

ModuleGenerator::MacroAssemblerScope::MacroAssemblerScope(LifoAlloc& lifo)
    : masmAlloc(&lifo), masm(masmAlloc, /* limitedSize= */ false) {}

ModuleGenerator::ModuleGenerator(const CodeMetadata& codeMeta,
                                 const CompilerEnvironment& compilerEnv,
                                 CompileState compileState,
                                 const mozilla::Atomic<bool>* cancelled,
                                 UniqueChars* error,
                                 UniqueCharsVector* warnings)
    : compileArgs_(codeMeta.compileArgs.get()),
      compileState_(compileState),
      error_(error),
      warnings_(warnings),
      cancelled_(cancelled),
      codeMeta_(&codeMeta),
      compilerEnv_(&compilerEnv),
      featureUsage_(FeatureUsage::None),
      codeBlock_(nullptr),
      linkData_(nullptr),
      lifo_(GENERATOR_LIFO_DEFAULT_CHUNK_SIZE, js::MallocArena),
      masm_(nullptr),
      debugStubCodeOffset_(0),
      requestTierUpStubCodeOffset_(0),
      updateCallRefMetricsStubCodeOffset_(0),
      lastPatchedCallSite_(0),
      startOfUnpatchedCallsites_(0),
      numCallRefMetrics_(0),
      numAllocSites_(0),
      parallel_(false),
      outstanding_(0),
      currentTask_(nullptr),
      batchedBytecode_(0),
      finishedFuncDefs_(false) {
  MOZ_ASSERT(codeMeta_->isPreparedForCompile());
}

ModuleGenerator::~ModuleGenerator() {
  MOZ_ASSERT_IF(finishedFuncDefs_, !batchedBytecode_);
  MOZ_ASSERT_IF(finishedFuncDefs_, !currentTask_);

  if (parallel_) {
    if (outstanding_) {
      AutoLockHelperThreadState lock;

      // Remove any pending compilation tasks from the worklist.
      size_t removed =
          RemovePendingWasmCompileTasks(taskState_, compileState_, lock);
      MOZ_ASSERT(outstanding_ >= removed);
      outstanding_ -= removed;

      // Wait until all active compilation tasks have finished.
      while (true) {
        MOZ_ASSERT(outstanding_ >= taskState_.finished().length());
        outstanding_ -= taskState_.finished().length();
        taskState_.finished().clear();

        MOZ_ASSERT(outstanding_ >= taskState_.numFailed());
        outstanding_ -= taskState_.numFailed();
        taskState_.numFailed() = 0;

        if (!outstanding_) {
          break;
        }

        taskState_.condVar().wait(lock); /* failed or finished */
      }
    }
  } else {
    MOZ_ASSERT(!outstanding_);
  }

  // Propagate error state.
  if (error_ && !*error_) {
    AutoLockHelperThreadState lock;
    *error_ = std::move(taskState_.errorMessage());
  }
}

bool ModuleGenerator::initializeCompleteTier(
    CodeMetadataForAsmJS* codeMetaForAsmJS) {
  MOZ_ASSERT(compileState_ != CompileState::LazyTier2);

  // Initialize our task system
  if (!initTasks()) {
    return false;
  }

  // If codeMetaForAsmJS is null, we're compiling wasm; else we're compiling
  // asm.js, in whih case it contains wasm::Code-lifetime asm.js-specific
  // information.
  MOZ_ASSERT(isAsmJS() == !!codeMetaForAsmJS);
  codeMetaForAsmJS_ = codeMetaForAsmJS;

  // Generate the shared stubs block, if we're compiling tier-1
  if (compilingTier1() && !prepareTier1()) {
    return false;
  }

  return startCompleteTier();
}

bool ModuleGenerator::initializePartialTier(const Code& code,
                                            uint32_t funcIndex) {
  MOZ_ASSERT(compileState_ == CompileState::LazyTier2);
  MOZ_ASSERT(!isAsmJS());

  // The implied codeMeta must be consistent with the one we already have.
  MOZ_ASSERT(&code.codeMeta() == codeMeta_);

  MOZ_ASSERT(!partialTieringCode_);
  partialTieringCode_ = &code;

  // Initialize our task system and start this partial tier
  return initTasks() && startPartialTier(funcIndex);
}

bool ModuleGenerator::funcIsCompiledInBlock(uint32_t funcIndex) const {
  return codeBlock_->funcToCodeRange[funcIndex] != BAD_CODE_RANGE;
}

const CodeRange& ModuleGenerator::funcCodeRangeInBlock(
    uint32_t funcIndex) const {
  MOZ_ASSERT(funcIsCompiledInBlock(funcIndex));
  const CodeRange& cr =
      codeBlock_->codeRanges[codeBlock_->funcToCodeRange[funcIndex]];
  MOZ_ASSERT(cr.isFunction());
  return cr;
}

static bool InRange(uint32_t caller, uint32_t callee) {
  // We assume JumpImmediateRange is defined conservatively enough that the
  // slight difference between 'caller' (which is really the return address
  // offset) and the actual base of the relative displacement computation
  // isn't significant.
  uint32_t range = std::min(JitOptions.jumpThreshold, JumpImmediateRange);
  if (caller < callee) {
    return callee - caller < range;
  }
  return caller - callee < range;
}

using OffsetMap =
    HashMap<uint32_t, uint32_t, DefaultHasher<uint32_t>, SystemAllocPolicy>;

bool ModuleGenerator::linkCallSites() {
  AutoCreatedBy acb(*masm_, "linkCallSites");

  masm_->haltingAlign(CodeAlignment);

  // Create far jumps for calls that have relative offsets that may otherwise
  // go out of range. This method is called both between function bodies (at a
  // frequency determined by the ISA's jump range) and once at the very end of
  // a module's codegen after all possible calls/traps have been emitted.

  OffsetMap existingCallFarJumps;
  for (; lastPatchedCallSite_ < codeBlock_->callSites.length();
       lastPatchedCallSite_++) {
    CallSiteKind kind = codeBlock_->callSites.kind(lastPatchedCallSite_);
    uint32_t callerOffset =
        codeBlock_->callSites.returnAddressOffset(lastPatchedCallSite_);
    const CallSiteTarget& target = callSiteTargets_[lastPatchedCallSite_];
    switch (kind) {
      case CallSiteKind::Import:
      case CallSiteKind::Indirect:
      case CallSiteKind::IndirectFast:
      case CallSiteKind::Symbolic:
      case CallSiteKind::Breakpoint:
      case CallSiteKind::EnterFrame:
      case CallSiteKind::LeaveFrame:
      case CallSiteKind::CollapseFrame:
      case CallSiteKind::FuncRef:
      case CallSiteKind::FuncRefFast:
      case CallSiteKind::ReturnStub:
      case CallSiteKind::StackSwitch:
      case CallSiteKind::RequestTierUp:
        break;
      case CallSiteKind::ReturnFunc:
      case CallSiteKind::Func: {
        auto patch = [this, kind](uint32_t callerOffset,
                                  uint32_t calleeOffset) {
          if (kind == CallSiteKind::ReturnFunc) {
            masm_->patchFarJump(CodeOffset(callerOffset), calleeOffset);
          } else {
            MOZ_ASSERT(kind == CallSiteKind::Func);
            masm_->patchCall(callerOffset, calleeOffset);
          }
        };
        if (funcIsCompiledInBlock(target.funcIndex())) {
          uint32_t calleeOffset =
              funcCodeRangeInBlock(target.funcIndex()).funcUncheckedCallEntry();
          if (InRange(callerOffset, calleeOffset)) {
            patch(callerOffset, calleeOffset);
            break;
          }
        }

        OffsetMap::AddPtr p =
            existingCallFarJumps.lookupForAdd(target.funcIndex());
        if (!p) {
          Offsets offsets;
          offsets.begin = masm_->currentOffset();
          if (!callFarJumps_.emplaceBack(target.funcIndex(),
                                         masm_->farJumpWithPatch().offset())) {
            return false;
          }
          offsets.end = masm_->currentOffset();
          if (masm_->oom()) {
            return false;
          }
          if (!codeBlock_->codeRanges.emplaceBack(CodeRange::FarJumpIsland,
                                                  offsets)) {
            return false;
          }
          if (!existingCallFarJumps.add(p, target.funcIndex(), offsets.begin)) {
            return false;
          }
        }

        patch(callerOffset, p->value());
        break;
      }
    }
  }

  masm_->flushBuffer();
  return !masm_->oom();
}

void ModuleGenerator::noteCodeRange(uint32_t codeRangeIndex,
                                    const CodeRange& codeRange) {
  switch (codeRange.kind()) {
    case CodeRange::Function:
      MOZ_ASSERT(codeBlock_->funcToCodeRange[codeRange.funcIndex()] ==
                 BAD_CODE_RANGE);
      codeBlock_->funcToCodeRange.insertInfallible(codeRange.funcIndex(),
                                                   codeRangeIndex);
      break;
    case CodeRange::InterpEntry:
      codeBlock_->lookupFuncExport(codeRange.funcIndex())
          .initEagerInterpEntryOffset(codeRange.begin());
      break;
    case CodeRange::JitEntry:
      // Nothing to do: jit entries are linked in the jump tables.
      break;
    case CodeRange::ImportJitExit:
      funcImports_[codeRange.funcIndex()].initJitExitOffset(codeRange.begin());
      break;
    case CodeRange::ImportInterpExit:
      funcImports_[codeRange.funcIndex()].initInterpExitOffset(
          codeRange.begin());
      break;
    case CodeRange::DebugStub:
      MOZ_ASSERT(!debugStubCodeOffset_);
      debugStubCodeOffset_ = codeRange.begin();
      break;
    case CodeRange::RequestTierUpStub:
      MOZ_ASSERT(!requestTierUpStubCodeOffset_);
      requestTierUpStubCodeOffset_ = codeRange.begin();
      break;
    case CodeRange::UpdateCallRefMetricsStub:
      MOZ_ASSERT(!updateCallRefMetricsStubCodeOffset_);
      updateCallRefMetricsStubCodeOffset_ = codeRange.begin();
      break;
    case CodeRange::TrapExit:
      MOZ_ASSERT(!linkData_->trapOffset);
      linkData_->trapOffset = codeRange.begin();
      break;
    case CodeRange::Throw:
      // Jumped to by other stubs, so nothing to do.
      break;
    case CodeRange::FarJumpIsland:
    case CodeRange::BuiltinThunk:
      MOZ_CRASH("Unexpected CodeRange kind");
  }
}

// Append every element from `srcVec` where `filterOp(srcElem) == true`.
// Applies `mutateOp(dstElem)` to every element that is appended.
template <class Vec, class FilterOp, class MutateOp>
static bool AppendForEach(Vec* dstVec, const Vec& srcVec, FilterOp filterOp,
                          MutateOp mutateOp) {
  // Eagerly grow the vector to the whole src vector. Any filtered elements
  // will be trimmed later.
  if (!dstVec->growByUninitialized(srcVec.length())) {
    return false;
  }

  using T = typename Vec::ElementType;

  T* dstBegin = dstVec->begin();
  T* dstEnd = dstVec->end();

  // We appended srcVec.length() elements at the beginning, so we append
  // elements starting at the first uninitialized element.
  T* dst = dstEnd - srcVec.length();

  for (const T* src = srcVec.begin(); src != srcVec.end(); src++) {
    if (!filterOp(src)) {
      continue;
    }
    new (dst) T(*src);
    mutateOp(dst - dstBegin, dst);
    dst++;
  }

  // Trim off the filtered out elements that were eagerly added at the
  // beginning
  size_t newSize = dst - dstBegin;
  if (newSize != dstVec->length()) {
    dstVec->shrinkTo(newSize);
  }

  return true;
}

template <typename T>
bool FilterNothing(const T* element) {
  return true;
}

// The same as the above `AppendForEach`, without performing any filtering.
template <class Vec, class MutateOp>
static bool AppendForEach(Vec* dstVec, const Vec& srcVec, MutateOp mutateOp) {
  using T = typename Vec::ElementType;
  return AppendForEach(dstVec, srcVec, &FilterNothing<T>, mutateOp);
}

bool ModuleGenerator::linkCompiledCode(CompiledCode& code) {
  AutoCreatedBy acb(*masm_, "ModuleGenerator::linkCompiledCode");
  JitContext jcx;

  // Combine observed features from the compiled code into the metadata
  featureUsage_ |= code.featureUsage;

  // Fold in compilation stats from all compiled functions in this block
  tierStats_.mergeCompileStats(code.compileStats);

  if (compilingTier1() && mode() == CompileMode::LazyTiering) {
    // All the CallRefMetrics from this batch of functions will start indexing
    // at our current length of metrics.
    uint32_t startOfCallRefMetrics = numCallRefMetrics_;

    for (const FuncCompileOutput& func : code.funcs) {
      // We only compile defined functions, not imported functions
      MOZ_ASSERT(func.index >= codeMeta_->numFuncImports);
      uint32_t funcDefIndex = func.index - codeMeta_->numFuncImports;

      // This function should only be compiled once
      MOZ_ASSERT(funcDefFeatureUsages_[funcDefIndex] == FeatureUsage::None);

      // Track the feature usage for this function
      funcDefFeatureUsages_[funcDefIndex] = func.featureUsage;

      // Record the range of CallRefMetrics this function owns. The metrics
      // will be processed below when we patch the offsets into code.
      MOZ_ASSERT(func.callRefMetricsRange.begin +
                     func.callRefMetricsRange.length <=
                 code.callRefMetricsPatches.length());
      funcDefCallRefMetrics_[funcDefIndex] = func.callRefMetricsRange;
      funcDefCallRefMetrics_[funcDefIndex].offsetBy(startOfCallRefMetrics);
    }
  } else {
    MOZ_ASSERT(funcDefFeatureUsages_.empty());
    MOZ_ASSERT(funcDefCallRefMetrics_.empty());
    MOZ_ASSERT(code.callRefMetricsPatches.empty());
#ifdef DEBUG
    for (const FuncCompileOutput& func : code.funcs) {
      MOZ_ASSERT(func.callRefMetricsRange.length == 0);
    }
#endif
  }

  if (compilingTier1()) {
    // All the AllocSites from this batch of functions will start indexing
    // at our current length.
    uint32_t startOfAllocSites = numAllocSites_;

    for (const FuncCompileOutput& func : code.funcs) {
      // We only compile defined functions, not imported functions
      MOZ_ASSERT(func.index >= codeMeta_->numFuncImports);
      uint32_t funcDefIndex = func.index - codeMeta_->numFuncImports;

      MOZ_ASSERT(func.allocSitesRange.begin + func.allocSitesRange.length <=
                 code.allocSitesPatches.length());
      funcDefAllocSites_[funcDefIndex] = func.allocSitesRange;
      funcDefAllocSites_[funcDefIndex].offsetBy(startOfAllocSites);
    }
  } else {
    MOZ_ASSERT(funcDefAllocSites_.empty());
    MOZ_ASSERT(code.allocSitesPatches.empty());
#ifdef DEBUG
    for (const FuncCompileOutput& func : code.funcs) {
      MOZ_ASSERT(func.allocSitesRange.length == 0);
    }
#endif
  }

  // Grab the perf spewers that were generated for these functions.
  if (!funcIonSpewers_.appendAll(std::move(code.funcIonSpewers)) ||
      !funcBaselineSpewers_.appendAll(std::move(code.funcBaselineSpewers))) {
    return false;
  }

  // Before merging in new code, if calls in a prior code range might go out of
  // range, insert far jumps to extend the range.

  if (!InRange(startOfUnpatchedCallsites_,
               masm_->size() + code.bytes.length())) {
    startOfUnpatchedCallsites_ = masm_->size();
    if (!linkCallSites()) {
      return false;
    }
  }

  // All code offsets in 'code' must be incremented by their position in the
  // overall module when the code was appended.

  masm_->haltingAlign(CodeAlignment);
  const size_t offsetInModule = masm_->size();
  if (code.bytes.length() != 0 &&
      !masm_->appendRawCode(code.bytes.begin(), code.bytes.length())) {
    return false;
  }

  auto codeRangeOp = [offsetInModule, this](uint32_t codeRangeIndex,
                                            CodeRange* codeRange) {
    codeRange->offsetBy(offsetInModule);
    noteCodeRange(codeRangeIndex, *codeRange);
  };
  if (!AppendForEach(&codeBlock_->codeRanges, code.codeRanges, codeRangeOp)) {
    return false;
  }

  InlinedCallerOffsetIndex baseInlinedCallerOffsetIndex =
      InlinedCallerOffsetIndex(codeBlock_->inliningContext.length());
  if (!codeBlock_->inliningContext.appendAll(std::move(code.inliningContext))) {
    return false;
  }

  if (!codeBlock_->callSites.appendAll(std::move(code.callSites),
                                       offsetInModule,
                                       baseInlinedCallerOffsetIndex)) {
    return false;
  }

  if (!callSiteTargets_.appendAll(code.callSiteTargets)) {
    return false;
  }

  if (!codeBlock_->trapSites.appendAll(std::move(code.trapSites),
                                       offsetInModule,
                                       baseInlinedCallerOffsetIndex)) {
    return false;
  }

  for (const SymbolicAccess& access : code.symbolicAccesses) {
    uint32_t patchAt = offsetInModule + access.patchAt.offset();
    if (!linkData_->symbolicLinks[access.target].append(patchAt)) {
      return false;
    }
  }

  for (const CallRefMetricsPatch& patch : code.callRefMetricsPatches) {
    if (!patch.hasOffsetOfOffsetPatch()) {
      numCallRefMetrics_ += 1;
      continue;
    }

    CodeOffset offset = CodeOffset(patch.offsetOfOffsetPatch());
    offset.offsetBy(offsetInModule);

    size_t callRefIndex = numCallRefMetrics_;
    numCallRefMetrics_ += 1;
    size_t callRefMetricOffset = callRefIndex * sizeof(CallRefMetrics);

    // Compute the offset of the metrics, and patch it. This may overflow,
    // in which case we report an OOM. We might need to do something smarter
    // here.
    if (callRefMetricOffset > (INT32_MAX / sizeof(CallRefMetrics))) {
      return false;
    }

    masm_->patchMove32(offset, Imm32(int32_t(callRefMetricOffset)));
  }

  // Use numAllocSites_ to patch bytecode specific AllocSite to its index in
  // the map.
  for (const AllocSitePatch& patch : code.allocSitesPatches) {
    uint32_t index = numAllocSites_;
    numAllocSites_ += 1;
    if (!patch.hasPatchOffset()) {
      continue;
    }

    CodeOffset offset = CodeOffset(patch.patchOffset());
    offset.offsetBy(offsetInModule);

    // Compute the offset of the AllocSite, and patch it. This may overflow,
    // in which case we report an OOM.
    if (index > INT32_MAX / sizeof(gc::AllocSite)) {
      return false;
    }
    uintptr_t allocSiteOffset = uintptr_t(index) * sizeof(gc::AllocSite);
    masm_->patchMove32(offset, Imm32(allocSiteOffset));
  }

  for (const CodeLabel& codeLabel : code.codeLabels) {
    LinkData::InternalLink link;
    link.patchAtOffset = offsetInModule + codeLabel.patchAt().offset();
    link.targetOffset = offsetInModule + codeLabel.target().offset();
#ifdef JS_CODELABEL_LINKMODE
    link.mode = codeLabel.linkMode();
#endif
    if (!linkData_->internalLinks.append(link)) {
      return false;
    }
  }

  // Transfer all stackmaps with the offset in module.
  if (!codeBlock_->stackMaps.appendAll(code.stackMaps, offsetInModule)) {
    return false;
  }

  auto unwindInfoOp = [=](uint32_t, CodeRangeUnwindInfo* i) {
    i->offsetBy(offsetInModule);
  };
  if (!AppendForEach(&codeBlock_->codeRangeUnwindInfos,
                     code.codeRangeUnwindInfos, unwindInfoOp)) {
    return false;
  }

  auto tryNoteFilter = [](const TryNote* tn) {
    // Filter out all try notes that were never given a try body. This may
    // happen due to dead code elimination.
    return tn->hasTryBody();
  };
  auto tryNoteOp = [=](uint32_t, TryNote* tn) { tn->offsetBy(offsetInModule); };
  return AppendForEach(&codeBlock_->tryNotes, code.tryNotes, tryNoteFilter,
                       tryNoteOp);
}

static bool ExecuteCompileTask(CompileTask* task, UniqueChars* error) {
  MOZ_ASSERT(task->lifo.isEmpty());
  MOZ_ASSERT(task->output.empty());

  switch (task->compilerEnv.tier()) {
    case Tier::Optimized:
      if (!IonCompileFunctions(task->codeMeta, task->codeTailMeta,
                               task->compilerEnv, task->lifo, task->inputs,
                               &task->output, error)) {
        return false;
      }
      break;
    case Tier::Baseline:
      if (!BaselineCompileFunctions(task->codeMeta, task->compilerEnv,
                                    task->lifo, task->inputs, &task->output,
                                    error)) {
        return false;
      }
      break;
  }

  MOZ_ASSERT(task->lifo.isEmpty());
  MOZ_ASSERT(task->inputs.length() == task->output.codeRanges.length());
  task->inputs.clear();
  return true;
}

void CompileTask::runHelperThreadTask(AutoLockHelperThreadState& lock) {
  UniqueChars error;
  bool ok;

  {
    AutoUnlockHelperThreadState unlock(lock);
    ok = ExecuteCompileTask(this, &error);
  }

  // Don't release the lock between updating our state and returning from this
  // method.

  if (!ok || !state.finished().append(this)) {
    state.numFailed()++;
    if (!state.errorMessage()) {
      state.errorMessage() = std::move(error);
    }
  }

  state.condVar().notify_one(); /* failed or finished */
}

ThreadType CompileTask::threadType() {
  switch (compileState) {
    case CompileState::Once:
    case CompileState::EagerTier1:
    case CompileState::LazyTier1:
      return ThreadType::THREAD_TYPE_WASM_COMPILE_TIER1;
    case CompileState::EagerTier2:
    case CompileState::LazyTier2:
      return ThreadType::THREAD_TYPE_WASM_COMPILE_TIER2;
    default:
      MOZ_CRASH();
  }
}

bool ModuleGenerator::initTasks() {
  // Determine whether parallel or sequential compilation is to be used and
  // initialize the CompileTasks that will be used in either mode.

  MOZ_ASSERT(GetHelperThreadCount() > 1);

  MOZ_ASSERT(!parallel_);
  uint32_t numTasks = 1;
  if (  // "obvious" prerequisites for doing off-thread compilation
      CanUseExtraThreads() && GetHelperThreadCPUCount() > 1 &&
      // For lazy tier 2 compilations, the current thread -- running a
      // WasmPartialTier2CompileTask -- is already dedicated to compiling the
      // to-be-tiered-up function.  So don't create a new task for it.
      compileState_ != CompileState::LazyTier2) {
    parallel_ = true;
    numTasks = 2 * GetMaxWasmCompilationThreads();
  }

  const CodeTailMetadata* codeTailMeta = nullptr;
  if (partialTieringCode_) {
    codeTailMeta = &partialTieringCode_->codeTailMeta();
  }

  if (!tasks_.initCapacity(numTasks)) {
    return false;
  }
  for (size_t i = 0; i < numTasks; i++) {
    tasks_.infallibleEmplaceBack(*codeMeta_, codeTailMeta, *compilerEnv_,
                                 compileState_, taskState_,
                                 COMPILATION_LIFO_DEFAULT_CHUNK_SIZE);
  }

  if (!freeTasks_.reserve(numTasks)) {
    return false;
  }
  for (size_t i = 0; i < numTasks; i++) {
    freeTasks_.infallibleAppend(&tasks_[i]);
  }
  return true;
}

bool ModuleGenerator::locallyCompileCurrentTask() {
  if (!ExecuteCompileTask(currentTask_, error_)) {
    return false;
  }
  if (!finishTask(currentTask_)) {
    return false;
  }
  currentTask_ = nullptr;
  batchedBytecode_ = 0;
  return true;
}

bool ModuleGenerator::finishTask(CompileTask* task) {
  AutoCreatedBy acb(*masm_, "ModuleGenerator::finishTask");

  masm_->haltingAlign(CodeAlignment);

  if (!linkCompiledCode(task->output)) {
    return false;
  }

  task->output.clear();

  MOZ_ASSERT(task->inputs.empty());
  MOZ_ASSERT(task->output.empty());
  MOZ_ASSERT(task->lifo.isEmpty());
  freeTasks_.infallibleAppend(task);
  return true;
}

bool ModuleGenerator::launchBatchCompile() {
  MOZ_ASSERT(currentTask_);

  if (cancelled_ && *cancelled_) {
    return false;
  }

  if (!parallel_) {
    return locallyCompileCurrentTask();
  }

  if (!StartOffThreadWasmCompile(currentTask_, compileState_)) {
    return false;
  }
  outstanding_++;
  currentTask_ = nullptr;
  batchedBytecode_ = 0;
  return true;
}

bool ModuleGenerator::finishOutstandingTask() {
  MOZ_ASSERT(parallel_);

  CompileTask* task = nullptr;
  {
    AutoLockHelperThreadState lock;
    while (true) {
      MOZ_ASSERT(outstanding_ > 0);

      if (taskState_.numFailed() > 0) {
        return false;
      }

      if (!taskState_.finished().empty()) {
        outstanding_--;
        task = taskState_.finished().popCopy();
        break;
      }

      taskState_.condVar().wait(lock); /* failed or finished */
    }
  }

  // Call outside of the compilation lock.
  return finishTask(task);
}

bool ModuleGenerator::compileFuncDef(uint32_t funcIndex,
                                     uint32_t lineOrBytecode,
                                     const uint8_t* begin, const uint8_t* end,
                                     Uint32Vector&& lineNums) {
  MOZ_ASSERT(!finishedFuncDefs_);
  MOZ_ASSERT(funcIndex < codeMeta_->numFuncs());

  if (compilingTier1()) {
    static_assert(MaxFunctionBytes < UINT32_MAX);
    uint32_t bodyLength = (uint32_t)(end - begin);
    funcDefRanges_.infallibleAppend(BytecodeRange(lineOrBytecode, bodyLength));
  }

  uint32_t threshold;
  switch (tier()) {
    case Tier::Baseline:
      threshold = JitOptions.wasmBatchBaselineThreshold;
      break;
    case Tier::Optimized:
      threshold = JitOptions.wasmBatchIonThreshold;
      break;
    default:
      MOZ_CRASH("Invalid tier value");
      break;
  }

  uint32_t funcBytecodeLength = end - begin;

  // Do not go over the threshold if we can avoid it: spin off the compilation
  // before appending the function if we would go over.  (Very large single
  // functions may still exceed the threshold but this is fine; it'll be very
  // uncommon and is in any case safely handled by the MacroAssembler's buffer
  // limit logic.)

  if (currentTask_ && currentTask_->inputs.length() &&
      batchedBytecode_ + funcBytecodeLength > threshold) {
    if (!launchBatchCompile()) {
      return false;
    }
  }

  if (!currentTask_) {
    if (freeTasks_.empty() && !finishOutstandingTask()) {
      return false;
    }
    currentTask_ = freeTasks_.popCopy();
  }

  if (!currentTask_->inputs.emplaceBack(funcIndex, lineOrBytecode, begin, end,
                                        std::move(lineNums))) {
    return false;
  }

  batchedBytecode_ += funcBytecodeLength;
  MOZ_ASSERT(batchedBytecode_ <= MaxCodeSectionBytes);
  return true;
}

bool ModuleGenerator::finishFuncDefs() {
  MOZ_ASSERT(!finishedFuncDefs_);

  if (currentTask_ && !locallyCompileCurrentTask()) {
    return false;
  }

  finishedFuncDefs_ = true;
  return true;
}

static void CheckCodeBlock(const CodeBlock& codeBlock) {
#if defined(DEBUG)
  // Assert all sorted metadata is sorted.
  uint32_t last = 0;
  for (const CodeRange& codeRange : codeBlock.codeRanges) {
    MOZ_ASSERT(codeRange.begin() >= last);
    last = codeRange.end();
  }

  codeBlock.callSites.checkInvariants();
  codeBlock.trapSites.checkInvariants(codeBlock.base());

  last = 0;
  for (const CodeRangeUnwindInfo& info : codeBlock.codeRangeUnwindInfos) {
    MOZ_ASSERT(info.offset() >= last);
    last = info.offset();
  }

  // Try notes should be sorted so that the end of ranges are in rising order
  // so that the innermost catch handler is chosen.
  last = 0;
  for (const wasm::TryNote& tryNote : codeBlock.tryNotes) {
    MOZ_ASSERT(tryNote.tryBodyEnd() >= last);
    MOZ_ASSERT(tryNote.tryBodyEnd() > tryNote.tryBodyBegin());
    last = tryNote.tryBodyBegin();
  }

  codeBlock.stackMaps.checkInvariants(codeBlock.base());

#endif
}

bool ModuleGenerator::startCodeBlock(CodeBlockKind kind) {
  MOZ_ASSERT(!masmScope_ && !linkData_ && !codeBlock_);
  masmScope_.emplace(lifo_);
  masm_ = &masmScope_->masm;
  linkData_ = js::MakeUnique<LinkData>();
  codeBlock_ = js::MakeUnique<CodeBlock>(kind);
  return !!linkData_ && !!codeBlock_;
}

bool ModuleGenerator::finishCodeBlock(CodeBlockResult* result) {
  // Now that all functions and stubs are generated and their CodeRanges
  // known, patch all calls (which can emit far jumps) and far jumps. Linking
  // can emit tiny far-jump stubs, so there is an ordering dependency here.

  if (!linkCallSites()) {
    return false;
  }

  for (CallFarJump far : callFarJumps_) {
    if (funcIsCompiledInBlock(far.targetFuncIndex)) {
      masm_->patchFarJump(
          jit::CodeOffset(far.jumpOffset),
          funcCodeRangeInBlock(far.targetFuncIndex).funcUncheckedCallEntry());
    } else if (!linkData_->callFarJumps.append(far)) {
      return false;
    }
  }

  lastPatchedCallSite_ = 0;
  startOfUnpatchedCallsites_ = 0;
  callSiteTargets_.clear();
  callFarJumps_.clear();

  // None of the linking or far-jump operations should emit masm metadata.

  MOZ_ASSERT(masm_->inliningContext().empty());
  MOZ_ASSERT(masm_->callSites().empty());
  MOZ_ASSERT(masm_->callSiteTargets().empty());
  MOZ_ASSERT(masm_->trapSites().empty());
  MOZ_ASSERT(masm_->symbolicAccesses().empty());
  MOZ_ASSERT(masm_->tryNotes().empty());
  MOZ_ASSERT(masm_->codeLabels().empty());

  masm_->finish();
  if (masm_->oom()) {
    return false;
  }

  // The try notes also need to be sorted to simplify lookup.
  std::sort(codeBlock_->tryNotes.begin(), codeBlock_->tryNotes.end());

  // These Vectors can get large and the excess capacity can be significant,
  // so realloc them down to size.

  codeBlock_->funcToCodeRange.shrinkStorageToFit();
  codeBlock_->codeRanges.shrinkStorageToFit();
  codeBlock_->inliningContext.shrinkStorageToFit();
  codeBlock_->callSites.shrinkStorageToFit();
  codeBlock_->trapSites.shrinkStorageToFit();
  codeBlock_->tryNotes.shrinkStorageToFit();

  // Mark the inlining context as done.
  codeBlock_->inliningContext.setImmutable();

  // Allocate the code storage, copy/link the code from `masm_` into it, set up
  // `codeBlock_->segment / codeBase / codeLength`, and adjust the metadata
  // offsets on `codeBlock_` accordingly.
  uint8_t* codeStart = nullptr;
  uint32_t codeLength = 0;
  if (partialTieringCode_) {
    // We're compiling a single function during tiering.  Place it in its own
    // hardware page, inside an existing CodeSegment if possible, or allocate a
    // new one and use that.  Either way, the chosen CodeSegment will be owned
    // by Code::lazyFuncSegments.
    MOZ_ASSERT(mode() == CompileMode::LazyTiering);

    // Try to allocate from Code::lazyFuncSegments. We do not allow a last-ditch
    // GC here as we may be running in OOL-code that is not ready for a GC.
    codeBlock_->segment = partialTieringCode_->createFuncCodeSegmentFromPool(
        *masm_, *linkData_, /* allowLastDitchGC = */ false, &codeStart,
        &codeLength);
  } else {
    // Create a new CodeSegment for the code and use that.
    CodeSource codeSource(*masm_, linkData_.get(), nullptr);
    codeLength = codeSource.lengthBytes();
    uint32_t allocationLength;
    codeBlock_->segment = CodeSegment::allocate(codeSource, nullptr,
                                                /* allowLastDitchGC = */ true,
                                                &codeStart, &allocationLength);
    tierStats_.codeBytesUsed += codeLength;
    tierStats_.codeBytesMapped += allocationLength;
  }

  if (!codeBlock_->segment) {
    warnf("failed to allocate executable memory for module");
    return false;
  }

  codeBlock_->codeBase = codeStart;
  codeBlock_->codeLength = codeLength;

  // Check that metadata is consistent with the actual code we generated,
  // linked, and loaded.
  CheckCodeBlock(*codeBlock_);

  // Free the macro assembler scope, and reset our masm pointer
  masm_ = nullptr;
  masmScope_ = mozilla::Nothing();

  result->codeBlock = std::move(codeBlock_);
  result->linkData = std::move(linkData_);
  result->funcIonSpewers = std::move(funcIonSpewers_);
  result->funcBaselineSpewers = std::move(funcBaselineSpewers_);
  return true;
}

bool ModuleGenerator::prepareTier1() {
  if (!startCodeBlock(CodeBlockKind::SharedStubs)) {
    return false;
  }

  // Initialize function definition ranges
  if (!funcDefRanges_.reserve(codeMeta_->numFuncDefs())) {
    return false;
  }

  // Initialize function definition feature usages (only used for lazy tiering
  // and inlining right now).
  if (mode() == CompileMode::LazyTiering &&
      (!funcDefFeatureUsages_.resize(codeMeta_->numFuncDefs()) ||
       !funcDefCallRefMetrics_.resize(codeMeta_->numFuncDefs()))) {
    return false;
  }

  // Initialize function definition alloc site ranges
  if (!funcDefAllocSites_.resize(codeMeta_->numFuncDefs())) {
    return false;
  }

  // Initialize function import metadata
  if (!funcImports_.resize(codeMeta_->numFuncImports)) {
    return false;
  }

  // The shared stubs code will contains function definitions for each imported
  // function.
  if (!FuncToCodeRangeMap::createDense(0, codeMeta_->numFuncImports,
                                       &codeBlock_->funcToCodeRange)) {
    return false;
  }

  uint32_t exportedFuncCount = 0;
  for (uint32_t funcIndex = 0; funcIndex < codeMeta_->numFuncImports;
       funcIndex++) {
    const FuncDesc& func = codeMeta_->funcs[funcIndex];
    if (func.isExported()) {
      exportedFuncCount++;
    }
  }
  if (!codeBlock_->funcExports.reserve(exportedFuncCount)) {
    return false;
  }

  for (uint32_t funcIndex = 0; funcIndex < codeMeta_->numFuncImports;
       funcIndex++) {
    const FuncDesc& func = codeMeta_->funcs[funcIndex];
    if (!func.isExported()) {
      continue;
    }

    codeBlock_->funcExports.infallibleEmplaceBack(
        FuncExport(funcIndex, func.isEager()));
  }

  // Generate the stubs for the module first
  CompiledCode& stubCode = tasks_[0].output;
  MOZ_ASSERT(stubCode.empty());

  if (!GenerateStubs(*codeMeta_, funcImports_, codeBlock_->funcExports,
                     &stubCode) ||
      !linkCompiledCode(stubCode)) {
    return false;
  }
  stubCode.clear();

  return finishCodeBlock(&sharedStubs_);
}

bool ModuleGenerator::startCompleteTier() {
#ifdef JS_JITSPEW
  completeTierStartTime_ = mozilla::TimeStamp::Now();
  JS_LOG(wasmPerf, Info,
         "CM=..%06lx  ModuleGenerator::startCompleteTier (%s, %u imports, %u "
         "functions)",
         (unsigned long)(uintptr_t(codeMeta_) & 0xFFFFFFL),
         tier() == Tier::Baseline ? "baseline" : "optimizing",
         (uint32_t)codeMeta_->numFuncImports,
         (uint32_t)codeMeta_->numFuncDefs());
#endif

  if (!startCodeBlock(CodeBlock::kindFromTier(tier()))) {
    return false;
  }

  // funcToCodeRange maps function indices to code-range indices and all
  // elements will be initialized by the time module generation is finished.

  if (!FuncToCodeRangeMap::createDense(
          codeMeta_->numFuncImports,
          codeMeta_->funcs.length() - codeMeta_->numFuncImports,
          &codeBlock_->funcToCodeRange)) {
    return false;
  }

  // Pre-reserve space for large Vectors to avoid the significant cost of the
  // final reallocs. In particular, the MacroAssembler can be enormous, so be
  // extra conservative. Since large over-reservations may fail when the
  // actual allocations will succeed, ignore OOM failures. Note,
  // shrinkStorageToFit calls at the end will trim off unneeded capacity.

  size_t codeSectionSize =
      codeMeta_->codeSectionRange ? codeMeta_->codeSectionRange->size() : 0;

  size_t estimatedCodeSize =
      size_t(1.2 * EstimateCompiledCodeSize(tier(), codeSectionSize));
  (void)masm_->reserve(std::min(estimatedCodeSize, MaxCodeBytesPerProcess));

  (void)codeBlock_->codeRanges.reserve(2 * codeMeta_->numFuncDefs());

  const size_t ByteCodesPerCallSite = 50;
  (void)codeBlock_->callSites.reserve(codeSectionSize / ByteCodesPerCallSite);

  const size_t ByteCodesPerOOBTrap = 10;
  (void)codeBlock_->trapSites.reserve(Trap::OutOfBounds,
                                      codeSectionSize / ByteCodesPerOOBTrap);

  // Accumulate all exported functions:
  // - explicitly marked as such;
  // - implicitly exported by being an element of function tables;
  // - implicitly exported by being the start function;
  // - implicitly exported by being used in global ref.func initializer
  // ModuleEnvironment accumulates this information for us during decoding,
  // transfer it to the FuncExportVector stored in Metadata.

  uint32_t exportedFuncCount = 0;
  for (uint32_t funcIndex = codeMeta_->numFuncImports;
       funcIndex < codeMeta_->funcs.length(); funcIndex++) {
    const FuncDesc& func = codeMeta_->funcs[funcIndex];
    if (func.isExported()) {
      exportedFuncCount++;
    }
  }
  if (!codeBlock_->funcExports.reserve(exportedFuncCount)) {
    return false;
  }

  for (uint32_t funcIndex = codeMeta_->numFuncImports;
       funcIndex < codeMeta_->funcs.length(); funcIndex++) {
    const FuncDesc& func = codeMeta_->funcs[funcIndex];

    if (!func.isExported()) {
      continue;
    }

    codeBlock_->funcExports.infallibleEmplaceBack(
        FuncExport(funcIndex, func.isEager()));
  }

  return true;
}

bool ModuleGenerator::startPartialTier(uint32_t funcIndex) {
#ifdef JS_JITSPEW
  UTF8Bytes name;
  if (!codeMeta_->getFuncNameForWasm(
          NameContext::Standalone, funcIndex,
          partialTieringCode_->codeTailMeta().nameSectionPayload.get(),
          &name) ||
      !name.append("\0", 1)) {
    return false;
  }
  uint32_t bytecodeLength =
      partialTieringCode_->codeTailMeta().funcDefRange(funcIndex).size();
  JS_LOG(wasmPerf, Info,
         "CM=..%06lx  ModuleGenerator::startPartialTier  fI=%-5u  sz=%-5u  %s",
         (unsigned long)(uintptr_t(codeMeta_) & 0xFFFFFFL), funcIndex,
         bytecodeLength, name.length() > 0 ? name.begin() : "(unknown-name)");
#endif

  if (!startCodeBlock(CodeBlock::kindFromTier(tier()))) {
    return false;
  }

  if (!FuncToCodeRangeMap::createDense(funcIndex, 1,
                                       &codeBlock_->funcToCodeRange)) {
    return false;
  }

  const FuncDesc& func = codeMeta_->funcs[funcIndex];
  if (func.isExported() && !codeBlock_->funcExports.emplaceBack(
                               FuncExport(funcIndex, func.isEager()))) {
    return false;
  }

  return true;
}

bool ModuleGenerator::finishTier(CompileAndLinkStats* tierStats,
                                 CodeBlockResult* result) {
  MOZ_ASSERT(finishedFuncDefs_);

  while (outstanding_ > 0) {
    if (!finishOutstandingTask()) {
      return false;
    }
  }

#ifdef DEBUG
  if (mode() != CompileMode::LazyTiering) {
    codeBlock_->funcToCodeRange.assertAllInitialized();
  }
#endif

  // Now that all funcs have been compiled, we can generate entry stubs for
  // the ones that have been exported.

  CompiledCode& stubCode = tasks_[0].output;
  MOZ_ASSERT(stubCode.empty());

  if (!GenerateEntryStubs(*codeMeta_, codeBlock_->funcExports, &stubCode)) {
    return false;
  }

  if (!linkCompiledCode(stubCode)) {
    return false;
  }

  // Return the tier statistics and clear them
  *tierStats = tierStats_;
  tierStats_.clear();

  return finishCodeBlock(result);
}

// Complete all tier-1 construction and return the resulting Module.  For this
// we will need both codeMeta_ (and maybe codeMetaForAsmJS_) and moduleMeta_.
SharedModule ModuleGenerator::finishModule(
    const BytecodeBufferOrSource& bytecode, ModuleMetadata& moduleMeta,
    JS::OptimizedEncodingListener* maybeCompleteTier2Listener) {
  MOZ_ASSERT(compilingTier1());

  CodeBlockResult tier1Result;
  CompileAndLinkStats tier1Stats;
  if (!finishTier(&tier1Stats, &tier1Result)) {
    return nullptr;
  }

  // Record what features we encountered in this module
  moduleMeta.featureUsage = featureUsage_;

  // Copy over data from the Bytecode, which is going away at the end of
  // compilation.
  //
  // In particular, convert the data- and custom-section ranges in the
  // ModuleMetadata into their full-fat versions by copying the underlying
  // data blocks.

  const BytecodeSource& bytecodeSource = bytecode.source();
  MOZ_ASSERT(moduleMeta.dataSegments.empty());
  if (!moduleMeta.dataSegments.reserve(moduleMeta.dataSegmentRanges.length())) {
    return nullptr;
  }
  for (const DataSegmentRange& srcRange : moduleMeta.dataSegmentRanges) {
    MutableDataSegment dstSeg = js_new<DataSegment>();
    if (!dstSeg) {
      return nullptr;
    }
    if (!dstSeg->init(bytecodeSource, srcRange)) {
      return nullptr;
    }
    moduleMeta.dataSegments.infallibleAppend(std::move(dstSeg));
  }

  MOZ_ASSERT(moduleMeta.customSections.empty());
  if (!moduleMeta.customSections.reserve(
          codeMeta_->customSectionRanges.length())) {
    return nullptr;
  }
  for (const CustomSectionRange& srcRange : codeMeta_->customSectionRanges) {
    BytecodeSpan nameSpan = bytecodeSource.getSpan(srcRange.name);
    CustomSection sec;
    if (!sec.name.append(nameSpan.data(), nameSpan.size())) {
      return nullptr;
    }
    MutableBytes payload = js_new<ShareableBytes>();
    if (!payload) {
      return nullptr;
    }
    BytecodeSpan payloadSpan = bytecodeSource.getSpan(srcRange.payload);
    if (!payload->append(payloadSpan.data(), payloadSpan.size())) {
      return nullptr;
    }
    sec.payload = std::move(payload);
    moduleMeta.customSections.infallibleAppend(std::move(sec));
  }

  // Allocate and initialize the code tail metadata now that we have seen the
  // entire module.
  MutableCodeTailMetadata codeTailMeta =
      js_new<CodeTailMetadata>(*moduleMeta.codeMeta);
  if (!codeTailMeta) {
    return nullptr;
  }
  moduleMeta.codeTailMeta = codeTailMeta;

  // Transfer the function definition ranges
  MOZ_ASSERT(funcDefRanges_.length() == codeMeta_->numFuncDefs());
  codeTailMeta->funcDefRanges = std::move(funcDefRanges_);

  // Transfer the function definition feature usages
  codeTailMeta->funcDefFeatureUsages = std::move(funcDefFeatureUsages_);
  codeTailMeta->funcDefCallRefs = std::move(funcDefCallRefMetrics_);
  codeTailMeta->funcDefAllocSites = std::move(funcDefAllocSites_);
  MOZ_ASSERT_IF(mode() != CompileMode::LazyTiering, numCallRefMetrics_ == 0);
  codeTailMeta->numCallRefMetrics = numCallRefMetrics_;

  if (tier() == Tier::Baseline) {
    codeTailMeta->numAllocSites = numAllocSites_;
  } else {
    MOZ_ASSERT(numAllocSites_ == 0);
    // Even if funcDefAllocSites were not created, e.g. single tier of
    // optimized compilation, the AllocSite array will exist.
    codeTailMeta->numAllocSites = codeMeta_->numTypes();
  }

  // Initialize debuggable module state
  if (debugEnabled()) {
    // We cannot use lazy or eager tiering with debugging
    MOZ_ASSERT(mode() == CompileMode::Once);

    // Mark the flag
    codeTailMeta->debugEnabled = true;

    // Grab or allocate a full copy of the bytecode of this module
    if (!bytecode.getOrCreateBuffer(&codeTailMeta->debugBytecode)) {
      return nullptr;
    }
    codeTailMeta->codeSectionBytecode =
        codeTailMeta->debugBytecode.codeSection();

    // Compute the hash for this module
    static_assert(sizeof(ModuleHash) <= sizeof(mozilla::SHA1Sum::Hash),
                  "The ModuleHash size shall not exceed the SHA1 hash size.");
    mozilla::SHA1Sum::Hash hash;
    bytecodeSource.computeHash(&hash);
    memcpy(codeTailMeta->debugHash, hash, sizeof(ModuleHash));
  }

  // Initialize lazy tiering module state
  if (mode() == CompileMode::LazyTiering) {
    // We cannot debug and use lazy tiering
    MOZ_ASSERT(!debugEnabled());

    // Grab or allocate a reference to the code section for this module
    if (bytecodeSource.hasCodeSection()) {
      codeTailMeta->codeSectionBytecode = bytecode.getOrCreateCodeSection();
      if (!codeTailMeta->codeSectionBytecode) {
        return nullptr;
      }
    }

    // Create call_ref hints
    codeTailMeta->callRefHints = MutableCallRefHints(
        js_pod_calloc<MutableCallRefHint>(numCallRefMetrics_));
    if (!codeTailMeta->callRefHints) {
      return nullptr;
    }
  }

  // Store a reference to the name section on the code metadata
  if (codeMeta_->nameSection) {
    codeTailMeta->nameSectionPayload =
        moduleMeta.customSections[codeMeta_->nameSection->customSectionIndex]
            .payload;
  } else {
    MOZ_ASSERT(codeTailMeta->nameSectionPayload == nullptr);
  }

  // Now that we have the name section we can send our blocks to the profiler.
  sharedStubs_.codeBlock->sendToProfiler(
      *codeMeta_, *codeTailMeta, codeMetaForAsmJS_,
      FuncIonPerfSpewerSpan(sharedStubs_.funcIonSpewers),
      FuncBaselinePerfSpewerSpan(sharedStubs_.funcBaselineSpewers));
  tier1Result.codeBlock->sendToProfiler(
      *codeMeta_, *codeTailMeta, codeMetaForAsmJS_,
      FuncIonPerfSpewerSpan(tier1Result.funcIonSpewers),
      FuncBaselinePerfSpewerSpan(tier1Result.funcBaselineSpewers));

  MutableCode code =
      js_new<Code>(mode(), *codeMeta_, *codeTailMeta, codeMetaForAsmJS_);
  if (!code || !code->initialize(std::move(funcImports_),
                                 std::move(sharedStubs_.codeBlock),
                                 std::move(sharedStubs_.linkData),
                                 std::move(tier1Result.codeBlock),
                                 std::move(tier1Result.linkData), tier1Stats)) {
    return nullptr;
  }

  // Copy in a couple of offsets.
  code->setDebugStubOffset(debugStubCodeOffset_);
  code->setRequestTierUpStubOffset(requestTierUpStubCodeOffset_);
  code->setUpdateCallRefMetricsStubOffset(updateCallRefMetricsStubCodeOffset_);

  // All the components are finished, so create the complete Module and start
  // tier-2 compilation if requested.

  MutableModule module = js_new<Module>(moduleMeta, *code);
  if (!module) {
    return nullptr;
  }

  // If we can serialize (not asm.js), are not planning on serializing already
  // and are testing serialization, then do a roundtrip through serialization
  // to test it out.
  if (!isAsmJS() && compileArgs_->features.testSerialization &&
      module->canSerialize()) {
    MOZ_RELEASE_ASSERT(mode() == CompileMode::Once &&
                       tier() == Tier::Serialized);

    Bytes serializedBytes;
    if (!module->serialize(&serializedBytes)) {
      return nullptr;
    }

    MutableModule deserializedModule =
        Module::deserialize(serializedBytes.begin(), serializedBytes.length());
    if (!deserializedModule) {
      return nullptr;
    }
    module = deserializedModule;

    // Perform storeOptimizedEncoding here instead of below so we don't have to
    // re-serialize the module.
    if (maybeCompleteTier2Listener && module->canSerialize()) {
      maybeCompleteTier2Listener->storeOptimizedEncoding(
          serializedBytes.begin(), serializedBytes.length());
      maybeCompleteTier2Listener = nullptr;
    }
  }

  if (compileState_ == CompileState::EagerTier1) {
    // Grab or allocate a copy of the code section bytecode
    SharedBytes codeSection;
    if (bytecodeSource.hasCodeSection()) {
      codeSection = bytecode.getOrCreateCodeSection();
      if (!codeSection) {
        return nullptr;
      }
    }

    // Kick off a background tier-2 compile task
    module->startTier2(codeSection, maybeCompleteTier2Listener);
  } else if (tier() == Tier::Serialized && maybeCompleteTier2Listener &&
             module->canSerialize()) {
    Bytes bytes;
    if (module->serialize(&bytes)) {
      maybeCompleteTier2Listener->storeOptimizedEncoding(bytes.begin(),
                                                         bytes.length());
    }
  }

#ifdef JS_JITSPEW
  size_t bytecodeSize = codeMeta_->codeSectionSize();
  double wallclockSeconds =
      (mozilla::TimeStamp::Now() - completeTierStartTime_).ToSeconds();
  JS_LOG(wasmPerf, Info,
         "CM=..%06lx  ModuleGenerator::finishModule      "
         "(%s, %.2f MB in %.3fs = %.2f MB/s)",
         (unsigned long)(uintptr_t(codeMeta_) & 0xFFFFFFL),
         tier() == Tier::Baseline ? "baseline" : "optimizing",
         double(bytecodeSize) / 1.0e6, wallclockSeconds,
         double(bytecodeSize) / 1.0e6 / wallclockSeconds);
#endif

  return module;
}

// Complete all tier-2 construction.  This merely augments the existing Code
// and does not require moduleMeta_.
bool ModuleGenerator::finishTier2(const Module& module) {
  MOZ_ASSERT(!compilingTier1());
  MOZ_ASSERT(compileState_ == CompileState::EagerTier2);
  MOZ_ASSERT(tier() == Tier::Optimized);
  MOZ_ASSERT(!compilerEnv_->debugEnabled());

  if (cancelled_ && *cancelled_) {
    return false;
  }

  CodeBlockResult tier2Result;
  CompileAndLinkStats tier2Stats;
  if (!finishTier(&tier2Stats, &tier2Result)) {
    return false;
  }

  if (MOZ_UNLIKELY(JitOptions.wasmDelayTier2)) {
    // Introduce an artificial delay when testing wasmDelayTier2, since we
    // want to exercise both tier1 and tier2 code in this case.
    ThisThread::SleepMilliseconds(500);
  }

  // While we still have the func spewers, send the code block to the profiler.
  tier2Result.codeBlock->sendToProfiler(
      *codeMeta_, module.codeTailMeta(), codeMetaForAsmJS_,
      FuncIonPerfSpewerSpan(tier2Result.funcIonSpewers),
      FuncBaselinePerfSpewerSpan(tier2Result.funcBaselineSpewers));

  return module.finishTier2(std::move(tier2Result.codeBlock),
                            std::move(tier2Result.linkData), tier2Stats);
}

bool ModuleGenerator::finishPartialTier2() {
  MOZ_ASSERT(!compilingTier1());
  MOZ_ASSERT(compileState_ == CompileState::LazyTier2);
  MOZ_ASSERT(tier() == Tier::Optimized);
  MOZ_ASSERT(!compilerEnv_->debugEnabled());

  if (cancelled_ && *cancelled_) {
    return false;
  }

  CodeBlockResult tier2Result;
  CompileAndLinkStats tier2Stats;
  if (!finishTier(&tier2Stats, &tier2Result)) {
    return false;
  }

  // While we still have the func spewers, send the code block to the profiler.
  tier2Result.codeBlock->sendToProfiler(
      *codeMeta_, partialTieringCode_->codeTailMeta(), codeMetaForAsmJS_,
      FuncIonPerfSpewerSpan(tier2Result.funcIonSpewers),
      FuncBaselinePerfSpewerSpan(tier2Result.funcBaselineSpewers));

  return partialTieringCode_->finishTier2(std::move(tier2Result.codeBlock),
                                          std::move(tier2Result.linkData),
                                          tier2Stats);
}

void ModuleGenerator::warnf(const char* msg, ...) {
  if (!warnings_) {
    return;
  }

  va_list ap;
  va_start(ap, msg);
  UniqueChars str(JS_vsmprintf(msg, ap));
  va_end(ap);
  if (!str) {
    return;
  }

  (void)warnings_->append(std::move(str));
}

size_t CompiledCode::sizeOfExcludingThis(
    mozilla::MallocSizeOf mallocSizeOf) const {
  return funcs.sizeOfExcludingThis(mallocSizeOf) +
         funcIonSpewers.sizeOfExcludingThis(mallocSizeOf) +
         funcBaselineSpewers.sizeOfExcludingThis(mallocSizeOf) +
         bytes.sizeOfExcludingThis(mallocSizeOf) +
         codeRanges.sizeOfExcludingThis(mallocSizeOf) +
         inliningContext.sizeOfExcludingThis(mallocSizeOf) +
         callSites.sizeOfExcludingThis(mallocSizeOf) +
         callSiteTargets.sizeOfExcludingThis(mallocSizeOf) +
         trapSites.sizeOfExcludingThis(mallocSizeOf) +
         symbolicAccesses.sizeOfExcludingThis(mallocSizeOf) +
         tryNotes.sizeOfExcludingThis(mallocSizeOf) +
         codeRangeUnwindInfos.sizeOfExcludingThis(mallocSizeOf) +
         callRefMetricsPatches.sizeOfExcludingThis(mallocSizeOf) +
         allocSitesPatches.sizeOfExcludingThis(mallocSizeOf) +
         codeLabels.sizeOfExcludingThis(mallocSizeOf);
}

size_t CompileTask::sizeOfExcludingThis(
    mozilla::MallocSizeOf mallocSizeOf) const {
  return lifo.sizeOfExcludingThis(mallocSizeOf) +
         inputs.sizeOfExcludingThis(mallocSizeOf) +
         output.sizeOfExcludingThis(mallocSizeOf);
}