dart::kernel::ScopeBuilder Class Reference

#include <scope_builder.h>

Public Member Functions
	ScopeBuilder (ParsedFunction *parsed_function)
virtual	~ScopeBuilder ()=default
ScopeBuildingResult *	BuildScopes ()

Private Member Functions
virtual void	ReportUnexpectedTag (const char *variant, Tag tag)

Detailed Description

Definition at line 23 of file scope_builder.h.

Constructor & Destructor Documentation

ScopeBuilder()

dart::kernel::ScopeBuilder::ScopeBuilder ( ParsedFunction *  parsed_function )

explicit

Definition at line 20 of file scope_builder.cc.

    : result_(nullptr),
      parsed_function_(parsed_function),
      translation_helper_(Thread::Current()),
      zone_(translation_helper_.zone()),
      current_function_scope_(nullptr),
      scope_(nullptr),
      depth_(0),
      name_index_(0),
      needs_expr_temp_(false),
      helper_(
          zone_,
          &translation_helper_,
          TypedDataView::Handle(Z, parsed_function->function().KernelLibrary()),
          parsed_function->function().KernelLibraryOffset()),
      constant_reader_(&helper_, &active_class_),
      inferred_type_metadata_helper_(&helper_, &constant_reader_),
      inferred_arg_type_metadata_helper_(
          &helper_,
          &constant_reader_,
          InferredTypeMetadataHelper::Kind::ArgType),
      procedure_attributes_metadata_helper_(&helper_),
      type_translator_(&helper_,
                       &constant_reader_,
                       &active_class_,
                       /*finalize=*/true) {
  const auto& kernel_program_info = KernelProgramInfo::Handle(
      Z, parsed_function->function().KernelProgramInfo());
  H.InitFromKernelProgramInfo(kernel_program_info);
  ASSERT(type_translator_.active_class_ == &active_class_);
}

~ScopeBuilder()

virtual dart::kernel::ScopeBuilder::~ScopeBuilder ( )

virtualdefault

Member Function Documentation

BuildScopes()

ScopeBuildingResult * dart::kernel::ScopeBuilder::BuildScopes

(

)

Definition at line 52 of file scope_builder.cc.

                                               {
  if (result_ != nullptr) return result_;
 
  ASSERT(scope_ == nullptr && depth_.loop_ == 0 && depth_.function_ == 0);
  result_ = new (Z) ScopeBuildingResult();
 
  const Function& function = parsed_function_->function();
 
  // Setup an [ActiveClassScope] and an [ActiveMemberScope] which will be used
  // e.g. for type translation.
  const Class& klass = Class::Handle(Z, function.Owner());
 
  Function& outermost_function =
      Function::Handle(Z, function.GetOutermostFunction());
 
  ActiveClassScope active_class_scope(&active_class_, &klass);
  ActiveMemberScope active_member(&active_class_, &outermost_function);
  FunctionType& signature = FunctionType::Handle(Z, function.signature());
  ActiveTypeParametersScope active_type_params(&active_class_, function,
                                               &signature, Z);
 
  LocalScope* enclosing_scope = nullptr;
  if (function.IsImplicitClosureFunction() && !function.is_static()) {
    // Create artificial enclosing scope for the tear-off that contains
    // captured receiver value. This ensure that AssertAssignable will correctly
    // load instantiator type arguments if they are needed.
    Class& klass = Class::Handle(Z, function.Owner());
    Type& klass_type = H.GetDeclarationType(klass);
    LocalVariable* receiver_variable =
        MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                     Symbols::This(), klass_type);
    parsed_function_->set_receiver_var(receiver_variable);
    receiver_variable->set_is_captured();
    enclosing_scope = new (Z) LocalScope(nullptr, 0, 0);
    enclosing_scope->set_context_level(0);
    enclosing_scope->AddVariable(receiver_variable);
    enclosing_scope->AddContextVariable(receiver_variable);
  } else if (function.HasParent()) {
    enclosing_scope = LocalScope::RestoreOuterScope(
        ContextScope::Handle(Z, function.context_scope()));
  }
  current_function_scope_ = scope_ = new (Z) LocalScope(enclosing_scope, 0, 0);
  scope_->set_begin_token_pos(function.token_pos());
  scope_->set_end_token_pos(function.end_token_pos());
 
  if (function.IsSuspendableFunction()) {
    LocalVariable* suspend_state_var =
        MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                     Symbols::SuspendStateVar(), AbstractType::dynamic_type());
    suspend_state_var->set_is_forced_stack();
    suspend_state_var->set_invisible(true);
    scope_->AddVariable(suspend_state_var);
    parsed_function_->set_suspend_state_var(suspend_state_var);
  }
 
  // Add function type arguments variable before current context variable.
  if (function.IsGeneric() || function.HasGenericParent()) {
    LocalVariable* type_args_var = MakeVariable(
        TokenPosition::kNoSource, TokenPosition::kNoSource,
        Symbols::FunctionTypeArgumentsVar(), AbstractType::dynamic_type());
    scope_->AddVariable(type_args_var);
    parsed_function_->set_function_type_arguments(type_args_var);
  }
 
  if (parsed_function_->has_arg_desc_var()) {
    scope_->AddVariable(parsed_function_->arg_desc_var());
  }
 
  LocalVariable* context_var = parsed_function_->current_context_var();
  context_var->set_is_forced_stack();
  scope_->AddVariable(context_var);
 
  parsed_function_->set_scope(scope_);
 
  helper_.SetOffset(function.kernel_offset());
 
  FunctionNodeHelper function_node_helper(&helper_);
  const ProcedureAttributesMetadata attrs =
      procedure_attributes_metadata_helper_.GetProcedureAttributes(
          function.kernel_offset());
 
  switch (function.kind()) {
    case UntaggedFunction::kImplicitClosureFunction: {
      const auto& parent = Function::Handle(Z, function.parent_function());
      const auto& target =
          Function::Handle(Z, function.ImplicitClosureTarget(Z));
 
      // For BuildGraphOfNoSuchMethodForwarder, since closures no longer
      // require arg_desc_var in all cases.
      if (target.IsNull() ||
          (parent.num_fixed_parameters() != target.num_fixed_parameters())) {
        needs_expr_temp_ = true;
      }
    }
      FALL_THROUGH;
    case UntaggedFunction::kClosureFunction:
    case UntaggedFunction::kRegularFunction:
    case UntaggedFunction::kGetterFunction:
    case UntaggedFunction::kSetterFunction:
    case UntaggedFunction::kConstructor: {
      const Tag tag = helper_.PeekTag();
      helper_.ReadUntilFunctionNode();
      function_node_helper.ReadUntilExcluding(
          FunctionNodeHelper::kPositionalParameters);
      // NOTE: FunctionNode is read further below the if.
 
      if (function.is_ffi_native() || function.IsFfiCallClosure()) {
        needs_expr_temp_ = true;
        // Calls with handles need try/catch variables.
        if (function.FfiCSignatureContainsHandles()) {
          ++depth_.try_;
          AddTryVariables();
          --depth_.try_;
          ++depth_.catch_;
          AddCatchVariables();
          FinalizeCatchVariables();
          --depth_.catch_;
        }
      }
      if (FlowGraphBuilder::IsRecognizedMethodForFlowGraph(function) &&
          FlowGraphBuilder::IsExpressionTempVarUsedInRecognizedMethodFlowGraph(
              function)) {
        needs_expr_temp_ = true;
      }
      intptr_t pos = 0;
      if (function.IsClosureFunction()) {
        LocalVariable* closure_parameter = MakeVariable(
            TokenPosition::kNoSource, TokenPosition::kNoSource,
            Symbols::ClosureParameter(), AbstractType::dynamic_type());
        closure_parameter->set_is_forced_stack();
        scope_->InsertParameterAt(pos++, closure_parameter);
      } else if (!function.is_static()) {
        // We use [is_static] instead of [IsStaticFunction] because the latter
        // returns `false` for constructors.
        Class& klass = Class::Handle(Z, function.Owner());
        Type& klass_type = H.GetDeclarationType(klass);
        LocalVariable* variable =
            MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                         Symbols::This(), klass_type);
        scope_->InsertParameterAt(pos++, variable);
        parsed_function_->set_receiver_var(variable);
 
        // We visit instance field initializers because they might contain
        // [Let] expressions and we need to have a mapping.
        if (tag == kConstructor) {
          Class& parent_class = Class::Handle(Z, function.Owner());
          Array& class_fields = Array::Handle(Z, parent_class.fields());
          Field& class_field = Field::Handle(Z);
          for (intptr_t i = 0; i < class_fields.Length(); ++i) {
            class_field ^= class_fields.At(i);
            if (!class_field.is_static()) {
              const auto& kernel_data =
                  TypedDataView::Handle(Z, class_field.KernelLibrary());
              ASSERT(!kernel_data.IsNull());
              intptr_t field_offset = class_field.kernel_offset();
              AlternativeReadingScopeWithNewData alt(
                  &helper_.reader_, &kernel_data, field_offset);
              FieldHelper field_helper(&helper_);
              field_helper.ReadUntilExcluding(FieldHelper::kInitializer);
              Tag initializer_tag =
                  helper_.ReadTag();  // read first part of initializer.
              if (initializer_tag == kSomething) {
                EnterScope(field_offset);
                VisitExpression();  // read initializer.
                ExitScope(field_helper.position_, field_helper.end_position_);
              }
            }
          }
        }
      } else if (function.IsFactory()) {
        LocalVariable* variable = MakeVariable(
            TokenPosition::kNoSource, TokenPosition::kNoSource,
            Symbols::TypeArgumentsParameter(), AbstractType::dynamic_type());
        scope_->InsertParameterAt(pos++, variable);
        result_->type_arguments_variable = variable;
      }
 
      ParameterTypeCheckMode type_check_mode =
          kTypeCheckForNonDynamicallyInvokedMethod;
      if (function.is_static()) {
        // In static functions we don't check anything.
        type_check_mode = kTypeCheckForStaticFunction;
      } else if (function.IsImplicitClosureFunction()) {
        // All non-covariant checks are either performed by the type system,
        // or by a dynamic closure call dispatcher/mirror if dynamically
        // invoked. For covariant checks, static targets never have covariant
        // arguments and dynamic targets do their own covariant checking.
        // Thus, implicit closure functions perform no checking internally.
        type_check_mode = kTypeCheckForImplicitClosureFunction;
      }
 
      // Continue reading FunctionNode:
      // read positional_parameters and named_parameters.
      AddPositionalAndNamedParameters(pos, type_check_mode, attrs);
 
      if (function.IsSuspendableFunction()) {
        // Read return type which is used to create a result of
        // async/async*/sync* function. It may reference receiver or type
        // arguments of the enclosing function which need to be captured.
        VisitDartType();
 
        // Visit optional future value type.
        if (helper_.ReadTag() == kSomething) {
          VisitDartType();
        }
      }
 
      // We generate a synthetic body for implicit closure functions - which
      // will forward the call to the real function.
      //     -> see BuildGraphOfImplicitClosureFunction
      if (!function.IsImplicitClosureFunction()) {
        helper_.SetOffset(function.kernel_offset());
        first_body_token_position_ = TokenPosition::kNoSource;
        VisitNode();
 
        // TODO(jensj): HACK: Push the begin token to after any parameters to
        // avoid crash when breaking on definition line of async method in
        // debugger. It seems that another scope needs to be added
        // in which captures are made, but I can't make that work.
        // This 'solution' doesn't crash, but I cannot see the parameters at
        // that particular breakpoint either.
        // Also push the end token to after the "}" to avoid crashing on
        // stepping past the last line (to the "}" character).
        if (first_body_token_position_.IsReal()) {
          scope_->set_begin_token_pos(first_body_token_position_);
        }
        if (scope_->end_token_pos().IsReal()) {
          scope_->set_end_token_pos(scope_->end_token_pos().Next());
        }
      }
      break;
    }
    case UntaggedFunction::kImplicitGetter:
    case UntaggedFunction::kImplicitSetter: {
      ASSERT(helper_.PeekTag() == kField);
      const bool is_setter = function.IsImplicitSetterFunction();
      const bool is_method = !function.IsStaticFunction();
      const auto& field = Field::Handle(Z, function.accessor_field());
      intptr_t pos = 0;
      if (is_method) {
        Class& klass = Class::Handle(Z, function.Owner());
        Type& klass_type = H.GetDeclarationType(klass);
        LocalVariable* variable =
            MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                         Symbols::This(), klass_type);
        scope_->InsertParameterAt(pos++, variable);
        parsed_function_->set_receiver_var(variable);
      }
      if (is_setter) {
        if (CompilerState::Current().is_aot()) {
          const intptr_t kernel_offset = field.kernel_offset();
          const InferredTypeMetadata parameter_type =
              inferred_type_metadata_helper_.GetInferredType(kernel_offset);
          result_->setter_value = MakeVariable(
              TokenPosition::kNoSource, TokenPosition::kNoSource,
              Symbols::Value(),
              AbstractType::ZoneHandle(Z, function.ParameterTypeAt(pos)),
              LocalVariable::kNoKernelOffset, /*is_late=*/false,
              /*inferred_type=*/nullptr,
              /*inferred_arg_type=*/&parameter_type);
        } else {
          result_->setter_value = MakeVariable(
              TokenPosition::kNoSource, TokenPosition::kNoSource,
              Symbols::Value(),
              AbstractType::ZoneHandle(Z, function.ParameterTypeAt(pos)));
        }
        scope_->InsertParameterAt(pos++, result_->setter_value);
 
        if (is_method) {
          if (field.is_covariant()) {
            result_->setter_value->set_is_explicit_covariant_parameter();
          } else if (!field.is_generic_covariant_impl() ||
                     (!attrs.has_non_this_uses && !attrs.has_tearoff_uses)) {
            result_->setter_value->set_type_check_mode(
                LocalVariable::kTypeCheckedByCaller);
          }
        }
      }
      break;
    }
    case UntaggedFunction::kImplicitStaticGetter: {
      ASSERT(helper_.PeekTag() == kField);
      ASSERT(function.IsStaticFunction());
      // In addition to static field initializers, scopes/local variables
      // are needed for implicit getters of static const fields, in order to
      // be able to evaluate their initializers in constant evaluator.
      if (Field::Handle(Z, function.accessor_field()).is_const()) {
        VisitNode();
      }
      break;
    }
    case UntaggedFunction::kFieldInitializer: {
      ASSERT(helper_.PeekTag() == kField);
      if (!function.is_static()) {
        Class& klass = Class::Handle(Z, function.Owner());
        Type& klass_type = H.GetDeclarationType(klass);
        LocalVariable* variable =
            MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                         Symbols::This(), klass_type);
        scope_->InsertParameterAt(0, variable);
        parsed_function_->set_receiver_var(variable);
      }
      VisitNode();
      break;
    }
    case UntaggedFunction::kDynamicInvocationForwarder: {
      const String& name = String::Handle(Z, function.name());
      ASSERT(Function::IsDynamicInvocationForwarderName(name));
 
      const auto& target = Function::ZoneHandle(Z, function.ForwardingTarget());
      ASSERT(!target.IsNull());
 
      if (FlowGraphBuilder::IsRecognizedMethodForFlowGraph(function) &&
          FlowGraphBuilder::IsExpressionTempVarUsedInRecognizedMethodFlowGraph(
              function)) {
        needs_expr_temp_ = true;
      }
 
      if (helper_.PeekTag() == kField) {
        // Create [this] variable.
        const Class& klass = Class::Handle(Z, function.Owner());
        parsed_function_->set_receiver_var(
            MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                         Symbols::This(), H.GetDeclarationType(klass)));
        scope_->InsertParameterAt(0, parsed_function_->receiver_var());
 
        // Create setter value variable.
        if (target.IsImplicitSetterFunction()) {
          result_->setter_value = MakeVariable(
              TokenPosition::kNoSource, TokenPosition::kNoSource,
              Symbols::Value(),
              AbstractType::ZoneHandle(Z, function.ParameterTypeAt(1)));
          scope_->InsertParameterAt(1, result_->setter_value);
        }
        break;
      }
 
      // We do not create dyn:* forwarders for method extractors, since those
      // can never return unboxed values (they return a closure).
      ASSERT(!target.IsMethodExtractor());
 
      helper_.ReadUntilFunctionNode();
      function_node_helper.ReadUntilExcluding(
          FunctionNodeHelper::kPositionalParameters);
 
      // Create [this] variable.
      intptr_t pos = 0;
      Class& klass = Class::Handle(Z, function.Owner());
      parsed_function_->set_receiver_var(
          MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                       Symbols::This(), H.GetDeclarationType(klass)));
      scope_->InsertParameterAt(pos++, parsed_function_->receiver_var());
 
      // Create all positional and named parameters.
      AddPositionalAndNamedParameters(
          pos, kTypeCheckEverythingNotCheckedInNonDynamicallyInvokedMethod,
          attrs);
      break;
    }
    case UntaggedFunction::kMethodExtractor: {
      // Add a receiver parameter. Though it is captured, we emit code to
      // explicitly copy it to a freshly-allocated closure.
      // Therefore, it isn't necessary to mark it as captured here.
      Class& klass = Class::Handle(Z, function.Owner());
      Type& klass_type = H.GetDeclarationType(klass);
      LocalVariable* variable =
          MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                       Symbols::This(), klass_type);
      scope_->InsertParameterAt(0, variable);
      parsed_function_->set_receiver_var(variable);
      break;
    }
    case UntaggedFunction::kFfiTrampoline: {
      needs_expr_temp_ = true;
      // Callbacks need try/catch variables.
      ++depth_.try_;
      AddTryVariables();
      --depth_.try_;
      ++depth_.catch_;
      AddCatchVariables();
      FinalizeCatchVariables();
      --depth_.catch_;
      FALL_THROUGH;
    }
    case UntaggedFunction::kInvokeFieldDispatcher: {
      if (function.IsDynamicClosureCallDispatcher()) {
        auto const vars = parsed_function_->EnsureDynamicClosureCallVars();
        ASSERT(vars != nullptr);
#define ADD_VAR(Name, _, __) scope_->AddVariable(vars->Name);
        FOR_EACH_DYNAMIC_CLOSURE_CALL_VARIABLE(ADD_VAR);
#undef ADD_VAR
        for (auto const& v : vars->named_argument_parameter_indices) {
          scope_->AddVariable(v);
        }
      }
    }
      FALL_THROUGH;
    case UntaggedFunction::kNoSuchMethodDispatcher: {
      for (intptr_t i = 0; i < function.NumParameters(); ++i) {
        LocalVariable* variable = MakeVariable(
            TokenPosition::kNoSource, TokenPosition::kNoSource,
            String::ZoneHandle(Z, function.ParameterNameAt(i)),
            AbstractType::ZoneHandle(Z, function.IsFfiCallbackTrampoline()
                                            ? function.ParameterTypeAt(i)
                                            : Object::dynamic_type().ptr()));
        bool added = scope_->InsertParameterAt(i, variable);
        ASSERT(added);
      }
      break;
    }
    case UntaggedFunction::kRecordFieldGetter: {
      needs_expr_temp_ = true;
      // Add a receiver parameter.
      Class& klass = Class::Handle(Z, function.Owner());
      parsed_function_->set_receiver_var(
          MakeVariable(TokenPosition::kNoSource, TokenPosition::kNoSource,
                       Symbols::This(), H.GetDeclarationType(klass)));
      scope_->InsertParameterAt(0, parsed_function_->receiver_var());
      break;
    }
    case UntaggedFunction::kIrregexpFunction:
      UNREACHABLE();
  }
  if (needs_expr_temp_) {
    parsed_function_->EnsureExpressionTemp();
  }
  if (parsed_function_->has_expression_temp_var()) {
    scope_->AddVariable(parsed_function_->expression_temp_var());
  }
  if (parsed_function_->function().MayHaveUncheckedEntryPoint()) {
    scope_->AddVariable(parsed_function_->EnsureEntryPointsTemp());
  }
 
  parsed_function_->AllocateVariables();
 
  // :suspend_state variable should be allocated to a fixed location in
  // the stack frame.
  RELEASE_ASSERT((parsed_function_->suspend_state_var() == nullptr) ||
                 (parsed_function_->suspend_state_var()->index().value() ==
                  SuspendState::kSuspendStateVarIndex));
 
  return result_;
}

ReportUnexpectedTag()

void dart::kernel::ScopeBuilder::ReportUnexpectedTag ( const char *  variant, Tag  tag  )

privatevirtual

Definition at line 496 of file scope_builder.cc.

                                                                   {
  const auto& script = Script::Handle(Z, Script());
  H.ReportError(script, TokenPosition::kNoSource,
                "Unexpected tag %d (%s) in %s, expected %s", tag,
                Reader::TagName(tag),
                parsed_function_->function().ToQualifiedCString(), variant);
}

---

The documentation for this class was generated from the following files:

• third_party/dart-lang/sdk/runtime/vm/compiler/frontend/scope_builder.h
• third_party/dart-lang/sdk/runtime/vm/compiler/frontend/scope_builder.cc