Add clang-format support for the experimental c/cpp plugin

build-support/bin/_generate_all_lockfiles_helper.py

@@ -10,6 +10,7 @@
 import sys
 from dataclasses import dataclass
 
+from pants.backend.cc.lint.clangformat.subsystem import ClangFormat
 from pants.backend.codegen.avro.java.subsystem import AvroSubsystem
 from pants.backend.codegen.protobuf.python.python_protobuf_subsystem import PythonProtobufMypyPlugin
 from pants.backend.codegen.protobuf.scala.subsystem import ScalaPBSubsystem
@@ -114,6 +115,7 @@ def jvm(cls, tool: type[JvmToolBase], *, backend: str | None = None) -> DefaultT
     DefaultTool.python(TerraformHcl2Parser, backend="pants.backend.experimental.terraform"),
     DefaultTool.python(DockerfileParser, backend="pants.backend.docker"),
     DefaultTool.python(TwineSubsystem),
+    DefaultTool.python(ClangFormat, backend="pants.backend.experimental.cc.lint.clangformat"),
     # JVM
     DefaultTool.jvm(JUnit),
     DefaultTool.jvm(GoogleJavaFormatSubsystem),

src/python/pants/backend/cc/lint/BUILD

@@ -0,0 +1,4 @@
+# Copyright 2022 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+python_sources()

src/python/pants/backend/cc/lint/clangformat/BUILD

@@ -0,0 +1,11 @@
+# Copyright 2022 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+python_sources(dependencies=[":lockfile"])
+resource(name="lockfile", source="clangformat.lock")
+
+python_tests(
+    name="rules_integration_test",
+    sources=["rules_integration_test.py"],
+    timeout=240,
+)

src/python/pants/backend/cc/lint/clangformat/clangformat.lock

@@ -0,0 +1,100 @@
+// This lockfile was autogenerated by Pants. To regenerate, run:
+//
+//    build-support/bin/generate_all_lockfiles.sh
+//
+// --- BEGIN PANTS LOCKFILE METADATA: DO NOT EDIT OR REMOVE ---
+// {
+//   "version": 2,
+//   "valid_for_interpreter_constraints": [
+//     "CPython<4,>=3.7"
+//   ],
+//   "generated_with_requirements": [
+//     "clang-format==14.0.3"
+//   ]
+// }
+// --- END PANTS LOCKFILE METADATA ---
+
+{
+  "allow_builds": true,
+  "allow_prereleases": false,
+  "allow_wheels": true,
+  "build_isolation": true,
+  "constraints": [],
+  "locked_resolves": [
+    {
+      "locked_requirements": [
+        {
+          "artifacts": [
+            {
+              "algorithm": "sha256",
+              "hash": "a084aa5a8b56b07893014790c8b051e795977b24980fda3af5eb193539a9653c",
+              "url": "https://files.pythonhosted.org/packages/aa/3f/00a6ca37de9a08b0d6717910c8479ade1aa5cb33d0a0897d1236447c2d36/clang_format-14.0.3-py2.py3-none-win_amd64.whl"
+            },
+            {
+              "algorithm": "sha256",
+              "hash": "2c7da4ff143146fe7b80894efd32842f45d58a3bd30e8fb559ce86b961700a3c",
+              "url": "https://files.pythonhosted.org/packages/2f/a7/01eebdafa44ca579383eb088dd6aa2179aa8c0bd661db17a6e52a5c5032b/clang_format-14.0.3-py2.py3-none-macosx_10_9_universal2.whl"
+            },
+            {
+              "algorithm": "sha256",
+              "hash": "7dce28e40f2af48b1d0d5a0211562e592395d32c58483c0cafd75e7cf3297b55",
+              "url": "https://files.pythonhosted.org/packages/4f/9e/be1a223599b501a116048fdb5ed3e96fee68ae5afcac4608f885b04265f5/clang_format-14.0.3-py2.py3-none-manylinux_2_12_i686.manylinux2010_i686.whl"
+            },
+            {
+              "algorithm": "sha256",
+              "hash": "00afee65c015d4c017d5b56524fc4a59829e5986ac159f0ab2c2147540a2b31a",
+              "url": "https://files.pythonhosted.org/packages/65/56/eb18d61a085ba018395155a2d658e0ee3aff0821a0b16d3d431b5ecec83b/clang_format-14.0.3-py2.py3-none-manylinux_2_17_s390x.manylinux2014_s390x.whl"
+            },
+            {
+              "algorithm": "sha256",
+              "hash": "b15a04d5c6ca463104518c461ef203f62f2a0b639d4e49d1362e2344ce25ec89",
+              "url": "https://files.pythonhosted.org/packages/66/91/52e3e26b31945dd2e58f0cdbd0697f424cb4bbd9ad254a3f800a3d3d2993/clang_format-14.0.3-py2.py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl"
+            },
+            {
+              "algorithm": "sha256",
+              "hash": "ae9746b024d900b3f2a5181fc9b1412a92a5df003793222cf9b646f21cb6f9eb",
+              "url": "https://files.pythonhosted.org/packages/6e/88/9b6497ed42b6b7ce06fb6da65f31f63ce87ccaa97d2acd2c6f31d63777ec/clang_format-14.0.3-py2.py3-none-win32.whl"
+            },
+            {
+              "algorithm": "sha256",
+              "hash": "73bc0bd21eacdee30b85e1315a6cff5685531d89905c3411de91816fc7cbce75",
+              "url": "https://files.pythonhosted.org/packages/91/19/b484a5df518e83fdf45482ce2396392932c5636c4a785b5d9c57d965b305/clang-format-14.0.3.tar.gz"
+            },
+            {
+              "algorithm": "sha256",
+              "hash": "778e4acc74e1dcbd8197dcf49142b4102242a83881fb117b86727c01e74c6941",
+              "url": "https://files.pythonhosted.org/packages/a3/4d/866c1f4bafd8ab2b957c7713aa2ae4db1363f781fb02fdd77ff531813abf/clang_format-14.0.3-py2.py3-none-manylinux_2_12_x86_64.manylinux2010_x86_64.whl"
+            },
+            {
+              "algorithm": "sha256",
+              "hash": "0925179fa10c444a07bdff5db6981868d07f109f1d8b5e5eaecc4f3b028e48a1",
+              "url": "https://files.pythonhosted.org/packages/b1/42/1a523349b0ae0ebcedb6278fade1fa5e0b303f9a18a480a342e4242d30bc/clang_format-14.0.3-py2.py3-none-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl"
+            }
+          ],
+          "project_name": "clang-format",
+          "requires_dists": [],
+          "requires_python": null,
+          "version": "14.0.3"
+        }
+      ],
+      "platform_tag": [
+        "cp39",
+        "cp39",
+        "macosx_12_0_x86_64"
+      ]
+    }
+  ],
+  "path_mappings": {},
+  "pex_version": "2.1.84",
+  "prefer_older_binary": false,
+  "requirements": [
+    "clang-format==14.0.3"
+  ],
+  "requires_python": [
+    "<4,>=3.7"
+  ],
+  "resolver_version": "pip-2020-resolver",
+  "style": "universal",
+  "transitive": true,
+  "use_pep517": null
+}

src/python/pants/backend/cc/lint/clangformat/rules.py

@@ -0,0 +1,101 @@
+# Copyright 2022 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass
+from typing import Iterable
+
+from pants.backend.cc.lint.clangformat.subsystem import ClangFormat
+from pants.backend.cc.target_types import CCSourceField
+from pants.backend.python.util_rules.pex import Pex, PexProcess, PexRequest
+from pants.core.goals.fmt import FmtRequest, FmtResult
+from pants.core.util_rules.config_files import ConfigFiles, ConfigFilesRequest
+from pants.engine.fs import Digest, MergeDigests, Snapshot
+from pants.engine.process import ProcessResult
+from pants.engine.rules import Get, MultiGet, Rule, collect_rules, rule
+from pants.engine.target import FieldSet
+from pants.engine.unions import UnionRule
+from pants.util.logging import LogLevel
+from pants.util.strutil import pluralize
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass(frozen=True)
+class ClangFormatFmtFieldSet(FieldSet):
+    required_fields = (CCSourceField,)
+
+    sources: CCSourceField
+
+
+class ClangFormatRequest(FmtRequest):
+    field_set_type = ClangFormatFmtFieldSet
+    name = ClangFormat.options_scope
+
+
+@rule(level=LogLevel.DEBUG)
+async def clangformat_fmt(request: ClangFormatRequest, clangformat: ClangFormat) -> FmtResult:
+    if clangformat.skip:
+        return FmtResult.skip(formatter_name=request.name)
+
+    clangformat_pex_get = Get(
+        Pex,
+        PexRequest(
+            output_filename="clangformat.pex",
+            internal_only=True,
+            requirements=clangformat.pex_requirements(),
+            interpreter_constraints=clangformat.interpreter_constraints,
+            main=clangformat.main,
+        ),
+    )
+
+    # Look for any/all of the clang-format configuration files (recurse sub-dirs)
+    config_files_get = Get(
+        ConfigFiles,
+        ConfigFilesRequest,
+        clangformat.config_request(request.snapshot.dirs),
+    )
+
+    clangformat_pex, config_files = await MultiGet(clangformat_pex_get, config_files_get)
+
+    # Merge source files, config files, and clang-format pex process
+    input_digest = await Get(
+        Digest,
+        MergeDigests(
+            [
+                request.snapshot.digest,
+                config_files.snapshot.digest,
+                clangformat_pex.digest,
+            ]
+        ),
+    )
+
+    result = await Get(
+        ProcessResult,
+        PexProcess(
+            clangformat_pex,
+            argv=(
+                "--style=file",  # Look for .clang-format files
+                "--fallback-style=webkit",  # Use WebKit if there is no config file
+                "-i",  # In-place edits
+                "--Werror",  # Formatting warnings as errors
+                *clangformat.args,  # User-added arguments
+                *request.snapshot.files,
+            ),
+            input_digest=input_digest,
+            output_files=request.snapshot.files,
+            description=f"Run clang-format on {pluralize(len(request.snapshot.files), 'file')}.",
+            level=LogLevel.DEBUG,
+        ),
+    )
+    output_snapshot = await Get(Snapshot, Digest, result.output_digest)
+    return FmtResult.create(request, result, output_snapshot, strip_chroot_path=True)
+
+
+def rules() -> Iterable[Rule | UnionRule]:
+    return (
+        *collect_rules(),
+        UnionRule(FmtRequest, ClangFormatRequest),
+    )