Module: MilkTea::LowererDyn

Included in:
Lowerer
Defined in:
lib/milk_tea/core/lowering/dyn.rb

Instance Method Summary collapse

Instance Method Details

#dyn_vtable_struct_type(interface) ⇒ Object 



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# File 'lib/milk_tea/core/lowering/dyn.rb', line 59

def dyn_vtable_struct_type(interface)
  void_ptr = Types::Registry.generic_instance("ptr", [@ctx.types.fetch("void")])
  fields = {}
  interface.methods.each do |method_name, method_binding|
    fn_params = [Types::Registry.parameter("data", void_ptr), *method_binding.params]
    fn_type = Types::Registry.function(nil, params: fn_params, return_type: method_binding.return_type)
    fields[method_name] = fn_type
  end
  Types::DynVtable.new(interface.name, fields)
end

#ensure_dyn_vtable(interface, concrete_type) ⇒ Object 



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# File 'lib/milk_tea/core/lowering/dyn.rb', line 70

def ensure_dyn_vtable(interface, concrete_type)
  concrete_type_name = sanitize_identifier(concrete_type.to_s)
  vtable_c_name = "mt_vtable_#{concrete_type_name}_#{interface.name}"
  return vtable_c_name if @dyn_generated_vtables&.key?(vtable_c_name)
  @dyn_generated_vtables ||= {}

  ensure_dyn_vtable_struct(interface)
  wrappers = gen_dyn_vtable_wrappers(concrete_type, interface)
  gen_dyn_vtable_constant(concrete_type, interface, vtable_c_name, wrappers)
  @dyn_generated_vtables[vtable_c_name] = true
  vtable_c_name
end

#ensure_dyn_vtable_struct(interface) ⇒ Object 



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# File 'lib/milk_tea/core/lowering/dyn.rb', line 83

def ensure_dyn_vtable_struct(interface)
  vtable_c_name = "mt_vtable_#{interface.name}"
  return if @artifacts.synthetic_structs.any? { |s| s.linkage_name == vtable_c_name }

  void_ptr = Types::Registry.generic_instance("ptr", [Types::Registry.primitive("void")])
  fields = interface.methods.map do |method_name, method_binding|
    fn_params = [Types::Registry.parameter("data", void_ptr), *method_binding.params]
    fn_type = Types::Registry.function(nil, params: fn_params, return_type: method_binding.return_type)
    IR::Field.new(name: method_name, type: fn_type)
  end

  @artifacts.synthetic_structs << IR::StructDecl.new(
    name: "vtable_#{interface.name}",
    linkage_name: vtable_c_name,
    fields:,
    packed: false,
    alignment: nil,
  )
end

#gen_dyn_vtable_constant(concrete_type, interface, vtable_c_name, wrappers) ⇒ Object 



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# File 'lib/milk_tea/core/lowering/dyn.rb', line 190

def gen_dyn_vtable_constant(concrete_type, interface, vtable_c_name, wrappers)
  vtable_full = dyn_vtable_struct_type(interface)
  fields = interface.methods.map do |method_name, _|
    wrapper_c_name = wrappers[method_name]
    field_type = vtable_full.field(method_name)
    IR::AggregateField.new(name: method_name, value: IR::Name.new(name: wrapper_c_name, type: field_type || @error_type, pointer: false))
  end
  @artifacts.synthetic_constants << IR::Constant.new(
    name: vtable_c_name,
    linkage_name: vtable_c_name,
    type: vtable_full,
    value: IR::AggregateLiteral.new(type: vtable_full, fields:),
  )
end

#gen_dyn_vtable_wrappers(concrete_type, interface) ⇒ Object 



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# File 'lib/milk_tea/core/lowering/dyn.rb', line 103

def gen_dyn_vtable_wrappers(concrete_type, interface)
  void_ptr = Types::Registry.generic_instance("ptr", [Types::Registry.primitive("void")])
  wrappers = {}
  concrete_type_name = sanitize_identifier(concrete_type.to_s)
  ptr_to_concrete = Types::Registry.generic_instance("ptr", [concrete_type])

  interface.methods.each do |method_name, method_binding|
    method_info = @method_definitions[[concrete_type, method_name]]
    raise LoweringError.new("no method #{method_name} for #{concrete_type}",
      line: 0, column: 0, path: @ctx.current_analysis_path) unless method_info

    method_analysis, method_ast = method_info
    method_key = method_ast.kind == :static ? "static:#{method_ast.name}" : method_ast.name
    real_binding = method_analysis.methods.fetch(concrete_type).fetch(method_key)
    real_c_name = function_binding_c_name(real_binding, module_name: method_analysis.module_name, receiver_type: concrete_type)
    wrapper_c_name = "__dyn_#{concrete_type_name}_#{method_name}"
    is_editable = method_ast.kind == :editable

    params = [
      IR::Param.new(name: "data", linkage_name: "data", type: void_ptr, pointer: false),
      *method_binding.params.map.with_index { |p, i| IR::Param.new(name: p.name, linkage_name: p.name || "arg#{i}", type: p.type, pointer: false) },
    ]

    body = if is_editable
      [
        IR::ReturnStmt.new(value: IR::Call.new(
          callee: real_c_name,
          arguments: [
            IR::Cast.new(target_type: ptr_to_concrete, expression: IR::Name.new(name: "data", type: void_ptr, pointer: false), type: ptr_to_concrete),
            *method_binding.params.map.with_index { |p, i| IR::Name.new(name: p.name || "arg#{i}", type: p.type, pointer: false) },
          ],
          type: method_binding.return_type,
        )),
      ]
    else
      if method_ast.kind == :static
        [
          IR::ReturnStmt.new(value: IR::Call.new(
            callee: real_c_name,
            arguments: method_binding.params.map.with_index { |p, i| IR::Name.new(name: p.name || "arg#{i}", type: p.type, pointer: false) },
            type: method_binding.return_type,
          )),
        ]
      elsif receiver_type_uses_pointer_lowering?(concrete_type)
        [
          IR::ReturnStmt.new(value: IR::Call.new(
            callee: real_c_name,
            arguments: [
              IR::Cast.new(target_type: ptr_to_concrete, expression: IR::Name.new(name: "data", type: void_ptr, pointer: false), type: ptr_to_concrete),
              *method_binding.params.map.with_index { |p, i| IR::Name.new(name: p.name || "arg#{i}", type: p.type, pointer: false) },
            ],
            type: method_binding.return_type,
          )),
        ]
      else
        # The receiver is always passed here; the C backend's
        # omitted-receiver call logic drops it when the target
        # method's unused receiver parameter was omitted (the same
        # single source of truth every ordinary method call uses,
        # which requires a String callee).
        [
          IR::ReturnStmt.new(value: IR::Call.new(
            callee: real_c_name,
            arguments: [
              IR::Unary.new(operator: "*", operand: IR::Cast.new(target_type: ptr_to_concrete, expression: IR::Name.new(name: "data", type: void_ptr, pointer: false), type: ptr_to_concrete), type: concrete_type),
              *method_binding.params.map.with_index { |p, i| IR::Name.new(name: p.name || "arg#{i}", type: p.type, pointer: false) },
            ],
            type: method_binding.return_type,
          )),
        ]
      end
    end

    @artifacts.synthetic_functions << IR::Function.new(
      name: "__dyn_#{concrete_type_name}_#{method_name}",
      linkage_name: wrapper_c_name,
      params:,
      return_type: method_binding.return_type,
      body:,
      entry_point: false,
    )
    wrappers[method_name] = wrapper_c_name
  end

  wrappers
end

#lower_adapt_call(expression, env:, type:, interface:) ⇒ Object 



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# File 'lib/milk_tea/core/lowering/dyn.rb', line 5

def lower_adapt_call(expression, env:, type:, interface:)
  argument = expression.arguments.fetch(0)
  arg_value = lower_expression(argument.value, env:)
  arg_type = infer_expression_type(argument.value, env:)
  concrete_type = ref_type?(arg_type) ? referenced_type(arg_type) : arg_type

  @dyn_vtables ||= {}
  key = [concrete_type, interface.name]
  return @dyn_vtables[key] unless @dyn_vtables[key].nil?

  vtable_struct_full = dyn_vtable_struct_type(interface)
  vtable_c_name = ensure_dyn_vtable(interface, concrete_type)

  void_ptr = Types::Registry.generic_instance("ptr", [@ctx.types.fetch("void")])
  vtable_field = IR::Cast.new(
    target_type: void_ptr,
    expression: IR::AddressOf.new(
      expression: IR::Name.new(name: vtable_c_name, type: vtable_struct_full, pointer: false),
      type: Types::Registry.generic_instance("ptr", [vtable_struct_full]),
    ),
    type: void_ptr,
  )

  result = IR::AggregateLiteral.new(
    type:,
    fields: [
      IR::AggregateField.new(name: "data", value: IR::Cast.new(target_type: void_ptr, expression: arg_value, type: void_ptr)),
      IR::AggregateField.new(name: "vtable", value: vtable_field),
    ],
  )
  @dyn_vtables[key] = result
  result
end

#lower_dyn_method_call(expression, receiver, method_binding, env:, type:) ⇒ Object 



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# File 'lib/milk_tea/core/lowering/dyn.rb', line 39

def lower_dyn_method_call(expression, receiver, method_binding, env:, type:)
  ir_expr = lower_expression(receiver, env:)
  void_ptr = Types::Registry.generic_instance("ptr", [@ctx.types.fetch("void")])
  dyn_type = infer_expression_type(receiver, env:)
  interface = dyn_type.interface_binding

  data_ptr = IR::Member.new(receiver: ir_expr, member: "data", type: void_ptr)
  vtable_field = IR::Member.new(receiver: ir_expr, member: "vtable", type: void_ptr)

  vtable_full = dyn_vtable_struct_type(interface)
  vtable_ptr_type = Types::Registry.generic_instance("ptr", [vtable_full])
  vtable_cast = IR::Cast.new(target_type: vtable_ptr_type, expression: vtable_field, type: vtable_ptr_type)

  fn_type = vtable_full.field(method_binding.name)
  vtable_method = IR::Member.new(receiver: vtable_cast, member: method_binding.name, type: fn_type)

  arguments = [data_ptr, *lower_call_arguments(expression.arguments, method_binding, env:)]
  IR::Call.new(callee: vtable_method, arguments:, type:)
end