C++ SmallVector::append方法代码示例

Constraint *Constraint::createDisjunction(ConstraintSystem &cs,
                                          ArrayRef<Constraint *> constraints,
                                          ConstraintLocator *locator,
                                          RememberChoice_t rememberChoice) {
  // Unwrap any disjunctions inside the disjunction constraint; we only allow
  // disjunctions at the top level.
  SmallVector<TypeVariableType *, 4> typeVars;
  bool unwrappedAny = false;
  SmallVector<Constraint *, 1> unwrapped;
  unsigned index = 0;
  for (auto constraint : constraints) {
    // Gather type variables from this constraint.
    gatherReferencedTypeVars(constraint, typeVars);

    // If we have a nested disjunction, unwrap it.
    if (constraint->getKind() == ConstraintKind::Disjunction) {
      // If we haven't unwrapped anything before, copy all of the constraints
      // we skipped.
      if (!unwrappedAny) {
        unwrapped.append(constraints.begin(), constraints.begin() + index);
        unwrappedAny = true;
      }

      // Add all of the constraints in the disjunction.
      unwrapped.append(constraint->getNestedConstraints().begin(),
                       constraint->getNestedConstraints().end());
    } else if (unwrappedAny) {
      // Since we unwrapped constraints before, add this constraint.
      unwrapped.push_back(constraint);
    }
    ++index;
  }

  // If we unwrapped anything, our list of constraints is the unwrapped list.
  if (unwrappedAny)
    constraints = unwrapped;

  assert(!constraints.empty() && "Empty disjunction constraint");

  // If there is a single constraint, this isn't a disjunction at all.
  if (constraints.size() == 1) {
    assert(!rememberChoice && "simplified an important disjunction?");
    return constraints.front();
  }

  // Create the disjunction constraint.
  uniqueTypeVariables(typeVars);
  unsigned size = sizeof(Constraint) 
                + typeVars.size() * sizeof(TypeVariableType*);
  void *mem = cs.getAllocator().Allocate(size, alignof(Constraint));
  auto disjunction =  new (mem) Constraint(ConstraintKind::Disjunction,
                              cs.allocateCopy(constraints), locator, typeVars);
  disjunction->RememberChoice = (bool) rememberChoice;
  return disjunction;
}

Parser::StmtResult Parser::ParseGotoStmt() {
  SourceLocation Loc = ConsumeToken();
  if(ConsumeIfPresent(tok::l_paren)) {
    // computed goto.
    SmallVector<Expr*, 4> Targets;
    do {
      auto E = ParseStatementLabelReference();
      if(E.isInvalid()) break;
      Targets.append(1, E.get());
    } while(ConsumeIfPresent(tok::comma));
    ExprResult Operand;
    bool ParseOperand = true;
    if(!ExpectAndConsume(tok::r_paren)) {
      if(!SkipUntil(tok::r_paren)) ParseOperand = false;
    }
    if(ParseOperand) Operand = ParseExpectedExpression();
    return Actions.ActOnComputedGotoStmt(Context, Loc, Targets, Operand, StmtLabel);
  }

  auto Destination = ParseStatementLabelReference();
  if(Destination.isInvalid()) {
    if(!IsPresent(tok::identifier)) {
      Diag.Report(getExpectedLoc(), diag::err_expected_stmt_label_after)
          << "GO TO";
      return StmtError();
    }
    auto IDInfo = Tok.getIdentifierInfo();
    auto IDLoc = ConsumeToken();
    auto VD = Actions.ExpectVarRef(IDLoc, IDInfo);
    if(!VD) return StmtError();
    auto Var = VarExpr::Create(Context, IDLoc, VD);

    // Assigned goto
    SmallVector<Expr*, 4> AllowedValues;
    if(ConsumeIfPresent(tok::l_paren)) {
      do {
        auto E = ParseStatementLabelReference();
        if(E.isInvalid()) {
          Diag.Report(getExpectedLoc(), diag::err_expected_stmt_label);
          SkipUntilNextStatement();
          return Actions.ActOnAssignedGotoStmt(Context, Loc, Var, AllowedValues, StmtLabel);
        }
        AllowedValues.append(1, E.get());
      } while(ConsumeIfPresent(tok::comma));
      ExpectAndConsume(tok::r_paren);
    }
    return Actions.ActOnAssignedGotoStmt(Context, Loc, Var, AllowedValues, StmtLabel);
  }
  // Uncoditional goto
  return Actions.ActOnGotoStmt(Context, Loc, Destination, StmtLabel);
}

/// Emit a collection downcast expression.
///
/// \param conditional Whether to emit a conditional downcast; if
/// false, this will emit a forced downcast.
static RValue emitCollectionDowncastExpr(SILGenFunction &SGF,
                                         ManagedValue source,
                                         Type sourceType,
                                         SILLocation loc,
                                         Type destType,
                                         SGFContext C,
                                         bool conditional) {
  // Compute substitutions for the intrinsic call.
  auto fromCollection = cast<BoundGenericStructType>(
                          sourceType->getCanonicalType());
  auto toCollection = cast<BoundGenericStructType>(
                        destType->getCanonicalType());
  // Get the intrinsic function.
  auto &ctx = SGF.getASTContext();
  FuncDecl *fn = nullptr;
  if (fromCollection->getDecl() == ctx.getArrayDecl()) {
    fn = conditional ? SGF.SGM.getArrayConditionalCast(loc)
                     : SGF.SGM.getArrayForceCast(loc);
  } else if (fromCollection->getDecl() == ctx.getDictionaryDecl()) {
    fn = (conditional
           ? SGF.SGM.getDictionaryDownCastConditional(loc)
           : SGF.SGM.getDictionaryDownCast(loc));
  } else if (fromCollection->getDecl() == ctx.getSetDecl()) {
    fn = (conditional
           ? SGF.SGM.getSetDownCastConditional(loc)
           : SGF.SGM.getSetDownCast(loc));
  } else {
    llvm_unreachable("unsupported collection upcast kind");
  }

  // This will have been diagnosed by the accessors above.
  if (!fn) return SGF.emitUndefRValue(loc, destType);

  auto fnGenericParams = fn->getGenericSignature()->getGenericParams();
  auto fromSubsts = fromCollection->gatherAllSubstitutions(
      SGF.SGM.SwiftModule, nullptr);
  auto toSubsts = toCollection->gatherAllSubstitutions(
      SGF.SGM.SwiftModule, nullptr);
  assert(fnGenericParams.size() == fromSubsts.size() + toSubsts.size() &&
         "wrong number of generic collection parameters");
  (void) fnGenericParams;

  // Form type parameter substitutions.
  SmallVector<Substitution, 4> subs;
  subs.append(fromSubsts.begin(), fromSubsts.end());
  subs.append(toSubsts.begin(), toSubsts.end());

  return SGF.emitApplyOfLibraryIntrinsic(loc, fn, subs, {source}, C);
}

int Compilation::performSingleCommand(const Job *Cmd) {
  assert(Cmd->getInputs().empty() &&
         "This can only be used to run a single command with no inputs");

  switch (Cmd->getCondition()) {
  case Job::Condition::CheckDependencies:
    return 0;
  case Job::Condition::RunWithoutCascading:
  case Job::Condition::Always:
  case Job::Condition::NewlyAdded:
    break;
  }

  if (!writeFilelistIfNecessary(Cmd, Diags))
    return 1;

  if (Level == OutputLevel::Verbose)
    Cmd->printCommandLine(llvm::errs());

  SmallVector<const char *, 128> Argv;
  Argv.push_back(Cmd->getExecutable());
  Argv.append(Cmd->getArguments().begin(), Cmd->getArguments().end());
  Argv.push_back(0);

  const char *ExecPath = Cmd->getExecutable();
  const char **argv = Argv.data();

  for (auto &envPair : Cmd->getExtraEnvironment())
    setenv(envPair.first, envPair.second, /*replacing=*/true);

  return ExecuteInPlace(ExecPath, argv);
}

void
CodeGenModule::EmitCXXGlobalInitFunc() {
  while (!CXXGlobalInits.empty() && !CXXGlobalInits.back())
    CXXGlobalInits.pop_back();

  if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty())
    return;

  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);

  // Create our global initialization function.
  llvm::Function *Fn = 
    CreateGlobalInitOrDestructFunction(*this, FTy, "_GLOBAL__I_a");

  if (!PrioritizedCXXGlobalInits.empty()) {
    SmallVector<llvm::Constant*, 8> LocalCXXGlobalInits;
    llvm::array_pod_sort(PrioritizedCXXGlobalInits.begin(), 
                         PrioritizedCXXGlobalInits.end()); 
    for (unsigned i = 0; i < PrioritizedCXXGlobalInits.size(); i++) {
      llvm::Function *Fn = PrioritizedCXXGlobalInits[i].second;
      LocalCXXGlobalInits.push_back(Fn);
    }
    LocalCXXGlobalInits.append(CXXGlobalInits.begin(), CXXGlobalInits.end());
    CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn,
                                                    &LocalCXXGlobalInits[0],
                                                    LocalCXXGlobalInits.size());
  }
  else
    CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn,
                                                     &CXXGlobalInits[0],
                                                     CXXGlobalInits.size());
  AddGlobalCtor(Fn);
  CXXGlobalInits.clear();
  PrioritizedCXXGlobalInits.clear();
}

/// Parse a free-standing where clause attached to a declaration, adding it to
/// a generic parameter list that may (or may not) already exist.
ParserStatus Parser::
parseFreestandingGenericWhereClause(GenericParamList *&genericParams,
                                    WhereClauseKind kind) {
  assert(Tok.is(tok::kw_where) && "Shouldn't call this without a where");
  
  // Push the generic arguments back into a local scope so that references will
  // find them.
  Scope S(this, ScopeKind::Generics);
  
  if (genericParams)
    for (auto pd : genericParams->getParams())
      addToScope(pd);
  
  SmallVector<RequirementRepr, 4> Requirements;
  if (genericParams)
    Requirements.append(genericParams->getRequirements().begin(),
                        genericParams->getRequirements().end());
  
  SourceLoc WhereLoc;
  bool FirstTypeInComplete;
  auto result = parseGenericWhereClause(WhereLoc, Requirements,
                                        FirstTypeInComplete);
  if (result.shouldStopParsing() || Requirements.empty())
    return result;

  if (!genericParams)
    diagnose(WhereLoc, diag::where_without_generic_params, unsigned(kind));
  else
    genericParams = GenericParamList::create(Context,
                                             genericParams->getLAngleLoc(),
                                             genericParams->getParams(),
                                             WhereLoc, Requirements,
                                             genericParams->getRAngleLoc());
  return ParserStatus();
}

Function *WebAssemblyLowerEmscriptenEHSjLj::getInvokeWrapper(CallOrInvoke *CI) {
  Module *M = CI->getModule();
  SmallVector<Type *, 16> ArgTys;
  Value *Callee = CI->getCalledValue();
  FunctionType *CalleeFTy;
  if (auto *F = dyn_cast<Function>(Callee))
    CalleeFTy = F->getFunctionType();
  else {
    auto *CalleeTy = cast<PointerType>(Callee->getType())->getElementType();
    CalleeFTy = dyn_cast<FunctionType>(CalleeTy);
  }

  std::string Sig = getSignature(CalleeFTy);
  if (InvokeWrappers.find(Sig) != InvokeWrappers.end())
    return InvokeWrappers[Sig];

  // Put the pointer to the callee as first argument
  ArgTys.push_back(PointerType::getUnqual(CalleeFTy));
  // Add argument types
  ArgTys.append(CalleeFTy->param_begin(), CalleeFTy->param_end());

  FunctionType *FTy = FunctionType::get(CalleeFTy->getReturnType(), ArgTys,
                                        CalleeFTy->isVarArg());
  Function *F = Function::Create(FTy, GlobalValue::ExternalLinkage,
                                 InvokePrefix + Sig, M);
  InvokeWrappers[Sig] = F;
  return F;
}

Value *llvm::concatenateVectors(IRBuilder<> &Builder, ArrayRef<Value *> Vecs) {
  unsigned NumVecs = Vecs.size();
  assert(NumVecs > 1 && "Should be at least two vectors");

  SmallVector<Value *, 8> ResList;
  ResList.append(Vecs.begin(), Vecs.end());
  do {
    SmallVector<Value *, 8> TmpList;
    for (unsigned i = 0; i < NumVecs - 1; i += 2) {
      Value *V0 = ResList[i], *V1 = ResList[i + 1];
      assert((V0->getType() == V1->getType() || i == NumVecs - 2) &&
             "Only the last vector may have a different type");

      TmpList.push_back(concatenateTwoVectors(Builder, V0, V1));
    }

    // Push the last vector if the total number of vectors is odd.
    if (NumVecs % 2 != 0)
      TmpList.push_back(ResList[NumVecs - 1]);

    ResList = TmpList;
    NumVecs = ResList.size();
  } while (NumVecs > 1);

  return ResList[0];
}

DIExpression *DIExpression::appendToStack(const DIExpression *Expr,
                                          ArrayRef<uint64_t> Ops) {
  assert(Expr && !Ops.empty() && "Can't append ops to this expression");
  assert(none_of(Ops,
                 [](uint64_t Op) {
                   return Op == dwarf::DW_OP_stack_value ||
                          Op == dwarf::DW_OP_LLVM_fragment;
                 }) &&
         "Can't append this op");

  // Append a DW_OP_deref after Expr's current op list if it's non-empty and
  // has no DW_OP_stack_value.
  //
  // Match .* DW_OP_stack_value (DW_OP_LLVM_fragment A B)?.
  Optional<FragmentInfo> FI = Expr->getFragmentInfo();
  unsigned DropUntilStackValue = FI.hasValue() ? 3 : 0;
  ArrayRef<uint64_t> ExprOpsBeforeFragment =
      Expr->getElements().drop_back(DropUntilStackValue);
  bool NeedsDeref = (Expr->getNumElements() > DropUntilStackValue) &&
                    (ExprOpsBeforeFragment.back() != dwarf::DW_OP_stack_value);
  bool NeedsStackValue = NeedsDeref || ExprOpsBeforeFragment.empty();

  // Append a DW_OP_deref after Expr's current op list if needed, then append
  // the new ops, and finally ensure that a single DW_OP_stack_value is present.
  SmallVector<uint64_t, 16> NewOps;
  if (NeedsDeref)
    NewOps.push_back(dwarf::DW_OP_deref);
  NewOps.append(Ops.begin(), Ops.end());
  if (NeedsStackValue)
    NewOps.push_back(dwarf::DW_OP_stack_value);
  return DIExpression::append(Expr, NewOps);
}

static IntrusiveRefCntPtr<DiagnosticsEngine>
createDiagnostics(unsigned int argc, char **argv) {
    IntrusiveRefCntPtr<DiagnosticIDs> DiagIDs(new DiagnosticIDs());

    // Buffer diagnostics from argument parsing so that we can output them using a
    // well formed diagnostic object.
    TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
    IntrusiveRefCntPtr<DiagnosticsEngine> InterimDiags(
        new DiagnosticsEngine(DiagIDs, new DiagnosticOptions(), DiagsBuffer));

    // Try to build a CompilerInvocation.
    SmallVector<const char *, 4> Args;
    Args.push_back("diagtool");
    Args.append(argv, argv + argc);
    std::unique_ptr<CompilerInvocation> Invocation(
        createInvocationFromCommandLine(Args, InterimDiags));
    if (!Invocation)
        return nullptr;

    // Build the diagnostics parser
    IntrusiveRefCntPtr<DiagnosticsEngine> FinalDiags =
        CompilerInstance::createDiagnostics(&Invocation->getDiagnosticOpts());
    if (!FinalDiags)
        return nullptr;

    // Flush any errors created when initializing everything. This could happen
    // for invalid command lines, which will probably give non-sensical results.
    DiagsBuffer->FlushDiagnostics(*FinalDiags);

    return FinalDiags;
}

/// Escape RegNode so that we can access it from child handlers. Find the call
/// to frameescape, if any, in the entry block and append RegNode to the list
/// of arguments.
int WinEHStatePass::escapeRegNode(Function &F) {
  // Find the call to frameescape and extract its arguments.
  IntrinsicInst *EscapeCall = nullptr;
  for (Instruction &I : F.getEntryBlock()) {
    IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
    if (II && II->getIntrinsicID() == Intrinsic::frameescape) {
      EscapeCall = II;
      break;
    }
  }
  SmallVector<Value *, 8> Args;
  if (EscapeCall) {
    auto Ops = EscapeCall->arg_operands();
    Args.append(Ops.begin(), Ops.end());
  }
  Args.push_back(RegNode);

  // Replace the call (if it exists) with new one. Otherwise, insert at the end
  // of the entry block.
  IRBuilder<> Builder(&F.getEntryBlock(),
                      EscapeCall ? EscapeCall : F.getEntryBlock().end());
  Builder.CreateCall(FrameEscape, Args);
  if (EscapeCall)
    EscapeCall->eraseFromParent();
  return Args.size() - 1;
}

LLVMContextImpl::~LLVMContextImpl() {
  // NOTE: We need to delete the contents of OwnedModules, but we have to
  // duplicate it into a temporary vector, because the destructor of Module
  // will try to remove itself from OwnedModules set.  This would cause
  // iterator invalidation if we iterated on the set directly.
  std::vector<Module*> Modules(OwnedModules.begin(), OwnedModules.end());
  DeleteContainerPointers(Modules);
  
  // Free the constants.  This is important to do here to ensure that they are
  // freed before the LeakDetector is torn down.
  std::for_each(ExprConstants.map_begin(), ExprConstants.map_end(),
                DropReferences());
  std::for_each(ArrayConstants.map_begin(), ArrayConstants.map_end(),
                DropFirst());
  std::for_each(StructConstants.map_begin(), StructConstants.map_end(),
                DropFirst());
  std::for_each(VectorConstants.map_begin(), VectorConstants.map_end(),
                DropFirst());
  ExprConstants.freeConstants();
  ArrayConstants.freeConstants();
  StructConstants.freeConstants();
  VectorConstants.freeConstants();
  DeleteContainerSeconds(CAZConstants);
  DeleteContainerSeconds(CPNConstants);
  DeleteContainerSeconds(UVConstants);
  InlineAsms.freeConstants();
  DeleteContainerSeconds(IntConstants);
  DeleteContainerSeconds(FPConstants);
  
  for (StringMap<ConstantDataSequential*>::iterator I = CDSConstants.begin(),
       E = CDSConstants.end(); I != E; ++I)
    delete I->second;
  CDSConstants.clear();

  // Destroy attributes.
  for (FoldingSetIterator<AttributesImpl> I = AttrsSet.begin(),
         E = AttrsSet.end(); I != E;) {
    FoldingSetIterator<AttributesImpl> Elem = I++;
    delete &*Elem;
  }

  // Destroy MDNodes.  ~MDNode can move and remove nodes between the MDNodeSet
  // and the NonUniquedMDNodes sets, so copy the values out first.
  SmallVector<MDNode*, 8> MDNodes;
  MDNodes.reserve(MDNodeSet.size() + NonUniquedMDNodes.size());
  for (FoldingSetIterator<MDNode> I = MDNodeSet.begin(), E = MDNodeSet.end();
       I != E; ++I)
    MDNodes.push_back(&*I);
  MDNodes.append(NonUniquedMDNodes.begin(), NonUniquedMDNodes.end());
  for (SmallVectorImpl<MDNode *>::iterator I = MDNodes.begin(),
         E = MDNodes.end(); I != E; ++I)
    (*I)->destroy();
  assert(MDNodeSet.empty() && NonUniquedMDNodes.empty() &&
         "Destroying all MDNodes didn't empty the Context's sets.");

  // Destroy MDStrings.
  DeleteContainerSeconds(MDStringCache);
}

Value *WebAssemblyLowerEmscriptenEHSjLj::wrapInvoke(CallOrInvoke *CI) {
  LLVMContext &C = CI->getModule()->getContext();

  // If we are calling a function that is noreturn, we must remove that
  // attribute. The code we insert here does expect it to return, after we
  // catch the exception.
  if (CI->doesNotReturn()) {
    if (auto *F = dyn_cast<Function>(CI->getCalledValue()))
      F->removeFnAttr(Attribute::NoReturn);
    CI->removeAttribute(AttributeList::FunctionIndex, Attribute::NoReturn);
  }

  IRBuilder<> IRB(C);
  IRB.SetInsertPoint(CI);

  // Pre-invoke
  // __THREW__ = 0;
  IRB.CreateStore(IRB.getInt32(0), ThrewGV);

  // Invoke function wrapper in JavaScript
  SmallVector<Value *, 16> Args;
  // Put the pointer to the callee as first argument, so it can be called
  // within the invoke wrapper later
  Args.push_back(CI->getCalledValue());
  Args.append(CI->arg_begin(), CI->arg_end());
  CallInst *NewCall = IRB.CreateCall(getInvokeWrapper(CI), Args);
  NewCall->takeName(CI);
  NewCall->setCallingConv(CI->getCallingConv());
  NewCall->setDebugLoc(CI->getDebugLoc());

  // Because we added the pointer to the callee as first argument, all
  // argument attribute indices have to be incremented by one.
  SmallVector<AttributeSet, 8> ArgAttributes;
  const AttributeList &InvokeAL = CI->getAttributes();

  // No attributes for the callee pointer.
  ArgAttributes.push_back(AttributeSet());
  // Copy the argument attributes from the original
  for (unsigned i = 0, e = CI->getNumArgOperands(); i < e; ++i)
    ArgAttributes.push_back(InvokeAL.getParamAttributes(i));

  // Reconstruct the AttributesList based on the vector we constructed.
  AttributeList NewCallAL =
      AttributeList::get(C, InvokeAL.getFnAttributes(),
                         InvokeAL.getRetAttributes(), ArgAttributes);
  NewCall->setAttributes(NewCallAL);

  CI->replaceAllUsesWith(NewCall);

  // Post-invoke
  // %__THREW__.val = __THREW__; __THREW__ = 0;
  Value *Threw = IRB.CreateLoad(ThrewGV, ThrewGV->getName() + ".val");
  IRB.CreateStore(IRB.getInt32(0), ThrewGV);
  return Threw;
}

DIExpression *DIExpression::append(const DIExpression *Expr,
                                   ArrayRef<uint64_t> Ops) {
  assert(Expr && !Ops.empty() && "Can't append ops to this expression");

  // Copy Expr's current op list.
  SmallVector<uint64_t, 16> NewOps;
  for (auto Op : Expr->expr_ops()) {
    // Append new opcodes before DW_OP_{stack_value, LLVM_fragment}.
    if (Op.getOp() == dwarf::DW_OP_stack_value ||
        Op.getOp() == dwarf::DW_OP_LLVM_fragment) {
      NewOps.append(Ops.begin(), Ops.end());

      // Ensure that the new opcodes are only appended once.
      Ops = None;
    }
    Op.appendToVector(NewOps);
  }

  NewOps.append(Ops.begin(), Ops.end());
  return DIExpression::get(Expr->getContext(), NewOps);
}

    bool canUseASTWithSnapshots(
        ArrayRef<ImmutableTextSnapshotRef> Snapshots) override {
      if (!TryExistingAST) {
        LOG_INFO_FUNC(High, "will resolve using up-to-date AST");
        return false;
      }

      // If there is an existing AST and the offset can be mapped back to the
      // document snapshot that was used to create it, then use that AST.
      // The downside is that we may return stale information, but we get the
      // benefit of increased responsiveness, since the request will not be
      // blocked waiting on the AST to be fully typechecked.

      ImmutableTextSnapshotRef InputSnap;
      if (auto EditorDoc = Lang.getEditorDocuments().findByPath(InputFile))
        InputSnap = EditorDoc->getLatestSnapshot();
      if (!InputSnap)
        return false;

      auto mappedBackOffset = [&]()->llvm::Optional<unsigned> {
        for (auto &Snap : Snapshots) {
          if (Snap->isFromSameBuffer(InputSnap)) {
            if (Snap->getStamp() == InputSnap->getStamp())
              return Offset;

            auto OptOffset = mapOffsetToOlderSnapshot(Offset, InputSnap, Snap);
            if (!OptOffset.hasValue())
              return None;

            // Check that the new and old offset still point to the same token.
            StringRef NewTok = getSourceToken(Offset, InputSnap);
            if (NewTok.empty())
              return None;
            if (NewTok == getSourceToken(OptOffset.getValue(), Snap))
              return OptOffset;

            return None;
          }
        }
        return None;
      };

      auto OldOffsetOpt = mappedBackOffset();
      if (OldOffsetOpt.hasValue()) {
        Offset = *OldOffsetOpt;
        PreviousASTSnaps.append(Snapshots.begin(), Snapshots.end());
        LOG_INFO_FUNC(High, "will try existing AST");
        return true;
      }

      LOG_INFO_FUNC(High, "will resolve using up-to-date AST");
      return false;
    }