Replace most usages of datatype() with @dataclass

contrib/go/src/python/pants/contrib/go/tasks/BUILD

@@ -6,6 +6,7 @@ python_library(
   dependencies=[
     '3rdparty/python/twitter/commons:twitter.common.collections',
     '3rdparty/python:ansicolors',
+    '3rdparty/python:dataclasses',
     'contrib/go/src/python/pants/contrib/go/subsystems',
     'contrib/go/src/python/pants/contrib/go/targets',
     'src/python/pants/base:build_environment',

contrib/go/src/python/pants/contrib/go/tasks/go_test.py

@@ -2,12 +2,12 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 from contextlib import contextmanager
+from dataclasses import dataclass
 
 from pants.base.build_environment import get_buildroot
 from pants.base.workunit import WorkUnitLabel
 from pants.task.testrunner_task_mixin import PartitionedTestRunnerTaskMixin, TestResult
 from pants.util.memo import memoized_property
-from pants.util.objects import datatype
 from pants.util.process_handler import SubprocessProcessHandler
 from pants.util.strutil import create_path_env_var, safe_shlex_join, safe_shlex_split
 
@@ -44,10 +44,10 @@ def _test_target_filter(self):
   def _validate_target(self, target):
     self.ensure_workspace(target)
 
-  class _GoTestTargetInfo(datatype([
-      ('import_path', str),
-      ('gopath', str),
-  ])): pass
+  @dataclass(frozen=True)
+  class _GoTestTargetInfo:
+    import_path: str
+    gopath: str
 
   def _generate_args_for_targets(self, targets):
     """

src/python/pants/backend/jvm/tasks/BUILD

@@ -122,6 +122,7 @@ python_library(
   sources = ['bundle_create.py'],
   dependencies = [
     '3rdparty/python/twitter/commons:twitter.common.collections',
+    '3rdparty/python:dataclasses',
     ':classpath_products',
     ':jvm_binary_task',
     'src/python/pants/backend/jvm/targets:jvm',
@@ -132,7 +133,6 @@ python_library(
     'src/python/pants/fs',
     'src/python/pants/util:dirutil',
     'src/python/pants/util:fileutil',
-    'src/python/pants/util:objects',
   ],
 )
 

src/python/pants/backend/jvm/tasks/bundle_create.py

@@ -2,6 +2,8 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 import os
+from dataclasses import dataclass
+from typing import Any
 
 from twitter.common.collections import OrderedSet
 
@@ -15,7 +17,6 @@
 from pants.build_graph.target_scopes import Scopes
 from pants.fs import archive
 from pants.util.dirutil import safe_mkdir
-from pants.util.objects import datatype
 
 
 class BundleCreate(BundleMixin, JvmBinaryTask):
@@ -51,8 +52,16 @@ def prepare(cls, options, round_manager):
   def product_types(cls):
     return ['jvm_archives', 'jvm_bundles', 'deployable_archives']
 
-  class App(datatype(['address', 'binary', 'bundles', 'id', 'deployjar', 'archive', 'target'])):
+  @dataclass(frozen=True)
+  class App:
     """A uniform interface to an app."""
+    address: Any
+    binary: Any
+    bundles: Any
+    id: Any
+    deployjar: Any
+    archive: Any
+    target: Any
 
     @staticmethod
     def is_app(target):

src/python/pants/backend/jvm/tasks/coverage/BUILD

@@ -4,6 +4,7 @@
 python_library(
   dependencies = [
     '3rdparty/python/twitter/commons:twitter.common.collections',
+    '3rdparty/python:dataclasses',
     'src/python/pants/backend/jvm/targets:java',
     'src/python/pants/backend/jvm/targets:scala',
     'src/python/pants/backend/jvm/subsystems:jvm_tool_mixin',
@@ -13,7 +14,6 @@ python_library(
     'src/python/pants/util:contextutil',
     'src/python/pants/util:dirutil',
     'src/python/pants/util:meta',
-    'src/python/pants/util:objects',
     'src/python/pants/util:strutil',
   ],
 )

src/python/pants/backend/jvm/tasks/coverage/engine.py

@@ -2,11 +2,12 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 from abc import ABC, abstractmethod
+from dataclasses import dataclass
+from typing import Any
 
 from pants.backend.jvm.targets.annotation_processor import AnnotationProcessor
 from pants.backend.jvm.targets.java_library import JavaLibrary
 from pants.backend.jvm.targets.scala_library import ScalaLibrary
-from pants.util.objects import datatype
 
 
 class CoverageEngine(ABC):
@@ -26,7 +27,8 @@ class CoverageEngine(ABC):
   is instantiated and used exactly once per `JUnitRun` task execution.
   """
 
-  class RunModifications(datatype(['classpath_prepend', 'extra_jvm_options'])):
+  @dataclass(frozen=True)
+  class RunModifications:
     """Modifications that should be made to the java command where code coverage is collected.
 
     The `classpath_prepend` field should be an iterable of classpath elements to prepend to java
@@ -35,6 +37,8 @@ class RunModifications(datatype(['classpath_prepend', 'extra_jvm_options'])):
     The `extra_jvm_options` should be a list of jvm options to include when executing the java
     command.
     """
+    classpath_prepend: Any
+    extra_jvm_options: Any
 
     @classmethod
     def create(cls, classpath_prepend=None, extra_jvm_options=None):

src/python/pants/backend/jvm/tasks/jvm_compile/rsc/BUILD

@@ -1,6 +1,7 @@
 python_library(
   dependencies = [
     '3rdparty/python/twitter/commons:twitter.common.collections',
+    '3rdparty/python:dataclasses',
     'src/python/pants/backend/jvm/subsystems:java',
     'src/python/pants/backend/jvm/subsystems:jvm_platform',
     'src/python/pants/backend/jvm/subsystems:rsc',

src/python/pants/backend/jvm/tasks/jvm_compile/rsc/rsc_compile.py

@@ -5,6 +5,7 @@
 import logging
 import os
 import re
+from dataclasses import dataclass
 
 from pants.backend.jvm.subsystems.dependency_context import DependencyContext  # noqa
 from pants.backend.jvm.subsystems.rsc import Rsc
@@ -31,7 +32,7 @@
 from pants.util.contextutil import Timer
 from pants.util.dirutil import fast_relpath, fast_relpath_optional, safe_mkdir
 from pants.util.memo import memoized_method, memoized_property
-from pants.util.objects import datatype, enum
+from pants.util.objects import enum
 from pants.util.strutil import safe_shlex_join
 
 
@@ -552,10 +553,10 @@ def record(k, v):
     all_jobs = cache_doublecheck_jobs + rsc_jobs + zinc_jobs + [write_to_cache_job]
     return (all_jobs, len(compile_jobs))
 
-  class RscZincMergedCompileContexts(datatype([
-      ('rsc_cc', RscCompileContext),
-      ('zinc_cc', CompileContext),
-  ])): pass
+  @dataclass(frozen=True)
+  class RscZincMergedCompileContexts:
+    rsc_cc: RscCompileContext
+    zinc_cc: CompileContext
 
   def select_runtime_context(self, merged_compile_context):
     return merged_compile_context.zinc_cc

src/python/pants/backend/jvm/tasks/reports/BUILD

@@ -3,12 +3,12 @@
 
 python_library(
   dependencies=[
+    '3rdparty/python:dataclasses',
     'src/python/pants/backend/jvm/tasks/reports/templates',
     'src/python/pants/base:mustache',
     'src/python/pants/util:dirutil',
     'src/python/pants/util:memo',
     'src/python/pants/util:meta',
-    'src/python/pants/util:objects',
     'src/python/pants/util:strutil',
   ],
 )

src/python/pants/backend/jvm/tasks/reports/junit_html_report.py

@@ -8,12 +8,13 @@
 import xml.etree.ElementTree as ET
 from abc import ABC, abstractmethod
 from collections import defaultdict
+from dataclasses import dataclass
 from functools import total_ordering
+from typing import Any, Optional
 
 from pants.base.mustache import MustacheRenderer
 from pants.util.dirutil import safe_mkdir_for, safe_walk
 from pants.util.memo import memoized_property
-from pants.util.objects import datatype
 
 
 _LOGGER = logging.getLogger(__name__)
@@ -140,11 +141,14 @@ def as_dict(self):
     return d
 
 
-class ReportTestCase(datatype(['name', 'time', 'failure', 'error', 'skipped'])):
+@dataclass(frozen=True, order=True)
+class ReportTestCase:
   """Data object for a JUnit test case"""
-
-  def __new__(cls, name, time, failure=None, error=None, skipped=False):
-    return super().__new__(cls, name, float(time), failure, error, skipped)
+  name: Any
+  time: float
+  failure: Optional[Any] = None
+  error: Optional[Any] = None
+  skipped: bool = False
 
   @memoized_property
   def icon_class(self):
@@ -244,7 +248,7 @@ def _parse_xml_file(xml_file):
 
       testcases.append(ReportTestCase(
         testcase.attrib['name'],
-        testcase.attrib.get('time', 0),
+        float(testcase.attrib.get('time', 0)),
         failure,
         error,
         skipped

src/python/pants/backend/native/subsystems/BUILD

@@ -4,6 +4,7 @@
 
 python_library(
   dependencies=[
+    '3rdparty/python:dataclasses',
     'src/python/pants/backend/native/config',
     'src/python/pants/backend/native/subsystems/binaries',
     'src/python/pants/backend/native/subsystems/utils',

src/python/pants/backend/native/subsystems/native_toolchain.py

@@ -1,6 +1,8 @@
 # Copyright 2018 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
+from dataclasses import dataclass
+from typing import Any
 
 from pants.backend.native.config.environment import (
   Assembler,
@@ -21,7 +23,6 @@
 from pants.engine.selectors import Get
 from pants.subsystem.subsystem import Subsystem
 from pants.util.memo import memoized_property
-from pants.util.objects import datatype
 
 
 class NativeToolchain(Subsystem):
@@ -69,7 +70,9 @@ def _libc_dev(self):
     return LibcDev.scoped_instance(self)
 
 
-class LibcObjects(datatype(['crti_object_paths'])): pass
+@dataclass(frozen=True)
+class LibcObjects:
+  crti_object_paths: Any
 
 
 class LinkerWrapperMixin:
@@ -83,22 +86,34 @@ def for_compiler(self, compiler, platform):
             .copy(exe_filename=compiler.exe_filename))
 
 
-class GCCLinker(datatype([('linker', Linker)]), LinkerWrapperMixin): pass
+@dataclass(frozen=True)
+class GCCLinker(LinkerWrapperMixin):
+  linker: Linker
 
 
-class LLVMLinker(datatype([('linker', Linker)]), LinkerWrapperMixin): pass
+@dataclass(frozen=True)
+class LLVMLinker(LinkerWrapperMixin):
+  linker: Linker
 
 
-class GCCCToolchain(datatype([('c_toolchain', CToolchain)])): pass
+@dataclass(frozen=True)
+class GCCCToolchain:
+  c_toolchain: CToolchain
 
 
-class GCCCppToolchain(datatype([('cpp_toolchain', CppToolchain)])): pass
+@dataclass(frozen=True)
+class GCCCppToolchain:
+  cpp_toolchain: CppToolchain
 
 
-class LLVMCToolchain(datatype([('c_toolchain', CToolchain)])): pass
+@dataclass(frozen=True)
+class LLVMCToolchain:
+  c_toolchain: CToolchain
 
 
-class LLVMCppToolchain(datatype([('cpp_toolchain', CppToolchain)])): pass
+@dataclass(frozen=True)
+class LLVMCppToolchain:
+  cpp_toolchain: CppToolchain
 
 
 @rule
@@ -120,11 +135,13 @@ def select_assembler(platform: Platform, native_toolchain: NativeToolchain) -> A
   yield assembler
 
 
-class BaseLinker(datatype([('linker', Linker)])):
+@dataclass(frozen=True)
+class BaseLinker:
   """A Linker which is not specific to any compiler yet.
 
   This represents Linker objects provided by subsystems, but may need additional information to be
   usable by a specific compiler."""
+  linker: Linker
 
 
 # TODO: select the appropriate `Platform` in the `@rule` decl using variants!
@@ -153,12 +170,14 @@ def select_llvm_linker(base_linker: BaseLinker) -> LLVMLinker:
   return LLVMLinker(base_linker.linker)
 
 
-class GCCInstallLocationForLLVM(datatype(['toolchain_dir'])):
+@dataclass(frozen=True)
+class GCCInstallLocationForLLVM:
   """This class is convertible into a list of command line arguments for clang and clang++.
 
   This is only used on Linux. The option --gcc-toolchain stops clang from searching for another gcc
   on the host system. The option appears to only exist on Linux clang and clang++.
   """
+  toolchain_dir: Any
 
   @property
   def as_clang_argv(self):
@@ -302,10 +321,10 @@ def select_gcc_cpp_toolchain(
   yield GCCCppToolchain(CppToolchain(working_cpp_compiler, working_linker))
 
 
-class ToolchainVariantRequest(datatype([
-    ('toolchain', NativeToolchain),
-    ('variant', ToolchainVariant),
-])): pass
+@dataclass(frozen=True)
+class ToolchainVariantRequest:
+  toolchain: NativeToolchain
+  variant: ToolchainVariant
 
 
 @rule

src/python/pants/backend/native/targets/BUILD

@@ -9,6 +9,7 @@ python_library(
     'src/python/pants/base:payload',
     'src/python/pants/base:payload_field',
     'src/python/pants/build_graph',
+    'src/python/pants/util:objects',
     'src/python/pants/util:memo',
   ],
 )

src/python/pants/backend/native/tasks/BUILD

@@ -4,6 +4,7 @@
 
 python_library(
   dependencies=[
+    '3rdparty/python:dataclasses',
     'src/python/pants/backend/native/config',
     'src/python/pants/backend/native/subsystems',
     'src/python/pants/backend/native/subsystems/packaging',