Allow customizing semgrep configurations; correct rule matching glob

docs/notes/2.23.x.md

@@ -149,6 +149,9 @@ Fixed pulling `helm_artifact`s from OCI repositories.
 
 Added `workspace_invalidation_sources` field to `adhoc_tool` and `shell_command` target types. This new field allows declaring that these targets depend on files without bringing those files into the execution sandbox, but that the target should still be re-executed if those files change. This is intended to work with the `workspace_environment` support where processes are executed in the workspace and not in a separate sandbox.
 
+#### Semgrep
+Semgrep now allows configuring the config directory, the semgrepignore config file, and will recursively discover all rules in the directory.
+
 ### Plugin API changes
 
 Fixed bug with workspace environment support where Pants used a workspace environment when it was searching for a local environment.

src/python/pants/backend/tools/semgrep/rules.py

@@ -15,7 +15,7 @@
 from pants.core.util_rules.partitions import Partition, Partitions
 from pants.core.util_rules.source_files import SourceFilesRequest, determine_source_files
 from pants.engine.addresses import Address
-from pants.engine.fs import CreateDigest, FileContent, MergeDigests, PathGlobs, Paths, Snapshot
+from pants.engine.fs import CreateDigest, FileContent, MergeDigests, PathGlobs, Paths
 from pants.engine.intrinsics import (
     create_digest_to_digest,
     digest_to_snapshot,
@@ -35,6 +35,10 @@
 logger = logging.getLogger(__name__)
 
 
+_SEMGREPIGNORE_FILE_NAME = ".semgrepignore"
+_DEFAULT_SEMGREP_CONFIG_DIR = ".semgrep"
+
+
 class SemgrepLintRequest(LintTargetsRequest):
     field_set_type = SemgrepFieldSet
     tool_subsystem = SemgrepSubsystem
@@ -43,29 +47,12 @@ class SemgrepLintRequest(LintTargetsRequest):
 @dataclass(frozen=True)
 class PartitionMetadata:
     config_files: frozenset[PurePath]
-    ignore_files: Snapshot
 
     @property
     def description(self) -> str:
         return ", ".join(sorted(str(path) for path in self.config_files))
 
 
-_IGNORE_FILE_NAME = ".semgrepignore"
-
-_RULES_DIR_NAME = ".semgrep"
-_RULES_FILES_GLOBS = (
-    ".semgrep.yml",
-    ".semgrep.yaml",
-    f"{_RULES_DIR_NAME}/*.yml",
-    f"{_RULES_DIR_NAME}/*.yaml",
-)
-
-
-@dataclass
-class SemgrepIgnoreFiles:
-    snapshot: Snapshot
-
-
 @dataclass
 class AllSemgrepConfigs:
     configs_by_dir: dict[PurePath, set[PurePath]]
@@ -84,26 +71,53 @@ def ancestor_configs(self, address: Address) -> Iterable[PurePath]:
             yield from self.configs_by_dir.get(ancestor, [])
 
 
-def _group_by_semgrep_dir(all_paths: Paths) -> AllSemgrepConfigs:
-    configs_by_dir = defaultdict(set)
-    for path_ in all_paths.files:
-        path = PurePath(path_)
-        # A rule like foo/bar/.semgrep/baz.yaml should behave like it's in in foo/bar, not
-        # foo/bar/.semgrep
-        parent = path.parent
-        config_directory = parent.parent if parent.name == _RULES_DIR_NAME else parent
-
-        configs_by_dir[config_directory].add(path)
+def _group_by_semgrep_dir(
+    all_config_files: Paths, all_config_dir_files: Paths, config_name: str
+) -> AllSemgrepConfigs:
+    configs_by_dir: dict[PurePath, set[PurePath]] = {}
+    for config_path in all_config_files.files:
+        # Rules like foo/semgrep.yaml should apply to the project at foo/
+        path = PurePath(config_path)
+        configs_by_dir.setdefault(path.parent, set()).add(path)
+
+    for config_path in all_config_dir_files.files:
+        # Rules like foo/bar/.semgrep/baz.yaml and foo/bar/.semgrep/baz/qux.yaml should apply to the
+        # project at foo/bar/
+        path = PurePath(config_path)
+        config_directory = next(
+            parent.parent for parent in path.parents if parent.name == config_name
+        )
+        configs_by_dir.setdefault(config_directory, set()).add(path)
 
     return AllSemgrepConfigs(configs_by_dir)
 
 
 @rule
-async def find_all_semgrep_configs() -> AllSemgrepConfigs:
-    all_paths = await path_globs_to_paths(
-        PathGlobs([f"**/{file_glob}" for file_glob in _RULES_FILES_GLOBS])
+async def find_all_semgrep_configs(semgrep: SemgrepSubsystem) -> AllSemgrepConfigs:
+    config_file_globs: tuple[str, ...] = ()
+    config_dir_globs: tuple[str, ...] = ()
+
+    if semgrep.config_name is None:
+        config_file_globs = ("**/.semgrep.yml", "**/.semgrep.yaml")
+        config_dir_globs = (
+            f"**/{_DEFAULT_SEMGREP_CONFIG_DIR}/**/*.yaml",
+            f"**/{_DEFAULT_SEMGREP_CONFIG_DIR}/**/*.yml",
+        )
+    elif semgrep.config_name.endswith((".yaml", ".yml")):
+        config_file_globs = (f"**/{semgrep.config_name}",)
+    else:
+        config_dir_globs = (
+            f"**/{semgrep.config_name}/**/*.yaml",
+            f"**/{semgrep.config_name}/**/*.yml",
+        )
+
+    all_config_files = await path_globs_to_paths(PathGlobs(config_file_globs))
+    all_config_dir_files = await path_globs_to_paths(PathGlobs(config_dir_globs))
+    return _group_by_semgrep_dir(
+        all_config_files,
+        all_config_dir_files,
+        (semgrep.config_name or _DEFAULT_SEMGREP_CONFIG_DIR),
     )
-    return _group_by_semgrep_dir(all_paths)
 
 
 @dataclass(frozen=True)
@@ -122,17 +136,10 @@ async def infer_relevant_semgrep_configs(
     return RelevantSemgrepConfigs(all_semgrep.ancestor_configs(request.field_set.address))
 
 
-@rule
-async def all_semgrep_ignore_files() -> SemgrepIgnoreFiles:
-    snapshot = await digest_to_snapshot(**implicitly(PathGlobs([f"**/{_IGNORE_FILE_NAME}"])))
-    return SemgrepIgnoreFiles(snapshot)
-
-
 @rule
 async def partition(
     request: SemgrepLintRequest.PartitionRequest[SemgrepFieldSet],
     semgrep: SemgrepSubsystem,
-    ignore_files: SemgrepIgnoreFiles,
 ) -> Partitions:
     if semgrep.skip:
         return Partitions()
@@ -149,7 +156,7 @@ async def partition(
             by_config[configs].append(field_set)
 
     return Partitions(
-        Partition(tuple(field_sets), PartitionMetadata(configs, ignore_files.snapshot))
+        Partition(tuple(field_sets), PartitionMetadata(configs))
         for configs, field_sets in by_config.items()
     )
 
@@ -169,10 +176,11 @@ async def lint(
     semgrep: SemgrepSubsystem,
     global_options: GlobalOptions,
 ) -> LintResult:
-    config_files, semgrep_pex, input_files, settings = await concurrently(
+    config_files, ignore_files, semgrep_pex, input_files, settings = await concurrently(
         digest_to_snapshot(
             **implicitly(PathGlobs(str(s) for s in request.partition_metadata.config_files))
         ),
+        digest_to_snapshot(**implicitly(PathGlobs([_SEMGREPIGNORE_FILE_NAME]))),
         create_venv_pex(**implicitly(semgrep.to_pex_request())),
         determine_source_files(
             SourceFilesRequest(field_set.source for field_set in request.elements)
@@ -186,7 +194,7 @@ async def lint(
                 input_files.snapshot.digest,
                 config_files.digest,
                 settings,
-                request.partition_metadata.ignore_files.digest,
+                ignore_files.digest,
             )
         )
     )

src/python/pants/backend/tools/semgrep/rules_integration_test.py

@@ -128,7 +128,8 @@ def run_semgrep(
 
     return tuple(
         rule_runner.request(
-            LintResult, [SemgrepLintRequest.Batch("", partition.elements, partition.metadata)]
+            LintResult,
+            [SemgrepLintRequest.Batch("", partition.elements, partition.metadata)],
         )
         for partition in partitions
     )
@@ -218,10 +219,19 @@ def test_multiple_targets(rule_runner: RuleRunner) -> None:
                 f"{DIR}/bad.txt": BAD_FILE,
                 f"{DIR}/BUILD": """file(name="f", source="bad.txt")""",
                 ".semgrep/one.yml": RULES,
-                ".semgrep/two.yml": RULES2,
+                ".semgrep/vendored/two.yml": RULES2,
             },
             id="via .semgrep directory",
         ),
+        pytest.param(
+            {
+                f"{DIR}/bad.txt": BAD_FILE,
+                f"{DIR}/BUILD": """file(name="f", source="bad.txt")""",
+                ".semgrep/one.yml": RULES,
+                ".semgrep/vendored/two.yml": RULES2,
+            },
+            id="via recursive .semgrep directory",
+        ),
     ],
 )
 def test_multiple_configs(rule_runner: RuleRunner, files: dict[str, str]) -> None:

src/python/pants/backend/tools/semgrep/rules_test.py

@@ -20,33 +20,51 @@ def configs(strs: dict[str, set[str]]) -> AllSemgrepConfigs:
 
 
 @pytest.mark.parametrize(
-    ("paths", "expected"),
+    ("config_files", "config_dir_files", "expected"),
     [
-        pytest.param((), configs({}), id="nothing"),
+        pytest.param((), (), configs({}), id="nothing"),
         pytest.param(
             ("foo/bar/.semgrep.yml",),
+            (),
             configs({"foo/bar": {"foo/bar/.semgrep.yml"}}),
             id="semgrep_file",
         ),
         pytest.param(
+            (),
             ("foo/bar/.semgrep/baz.yml", "foo/bar/.semgrep/qux.yml"),
             configs({"foo/bar": {"foo/bar/.semgrep/baz.yml", "foo/bar/.semgrep/qux.yml"}}),
             id="semgrep_dir",
         ),
         pytest.param(
-            (
-                "foo/bar/.semgrep.yml",
-                "foo/bar/.semgrep/baz.yml",
-            ),
+            ("foo/bar/.semgrep.yml",),
+            ("foo/bar/.semgrep/baz.yml",),
             configs({"foo/bar": {"foo/bar/.semgrep.yml", "foo/bar/.semgrep/baz.yml"}}),
             id="both_file_and_dir",
         ),
+        pytest.param(
+            (),
+            (
+                "foo/bar/.semgrep/.semgrep.yml",
+                "foo/bar/.semgrep/baz1.yml",
+                "foo/bar/.semgrep/quz/baz2.yml",
+            ),
+            configs(
+                {
+                    "foo/bar": {
+                        "foo/bar/.semgrep/.semgrep.yml",
+                        "foo/bar/.semgrep/baz1.yml",
+                        "foo/bar/.semgrep/quz/baz2.yml",
+                    }
+                }
+            ),
+            id="recursively_find_yamls",
+        ),
         pytest.param(
             (
-                "foo/.semgrep/baz.yml",
                 "foo/bar/.semgrep.yml",
                 "foo/bar/qux/.semgrep.yml",
             ),
+            ("foo/.semgrep/baz.yml",),
             configs(
                 {
                     "foo": {"foo/.semgrep/baz.yml"},
@@ -58,15 +76,21 @@ def configs(strs: dict[str, set[str]]) -> AllSemgrepConfigs:
         ),
         # at the top level should be okay too
         pytest.param(
-            (".semgrep.yml", ".semgrep/foo.yml"),
+            (".semgrep.yml",),
+            (".semgrep/foo.yml",),
             configs({"": {".semgrep.yml", ".semgrep/foo.yml"}}),
             id="top_level",
         ),
     ],
 )
-def test_group_by_group_by_semgrep_dir(paths: tuple[str, ...], expected: AllSemgrepConfigs):
-    input = Paths(files=paths, dirs=())
-    result = rules._group_by_semgrep_dir(input)
+def test_group_by_group_by_semgrep_dir(
+    config_files: tuple[str, ...],
+    config_dir_files: tuple[str, ...],
+    expected: AllSemgrepConfigs,
+):
+    config_file_paths = Paths(files=config_files, dirs=())
+    config_dir_file_paths = Paths(files=config_dir_files, dirs=())
+    result = rules._group_by_semgrep_dir(config_file_paths, config_dir_file_paths, ".semgrep")
     assert result == expected
 
 

src/python/pants/backend/tools/semgrep/subsystem.py

@@ -12,7 +12,7 @@
 from pants.engine.rules import Rule, collect_rules
 from pants.engine.target import Dependencies, FieldSet, SingleSourceField, Target
 from pants.engine.unions import UnionRule
-from pants.option.option_types import ArgsListOption, BoolOption, SkipOption
+from pants.option.option_types import ArgsListOption, BoolOption, SkipOption, StrOption
 from pants.util.strutil import softwrap
 
 
@@ -51,6 +51,18 @@ class SemgrepSubsystem(PythonToolBase):
     register_lockfile = True
     default_lockfile_resource = ("pants.backend.tools.semgrep", "semgrep.lock")
 
+    config_name = StrOption(
+        default=None,
+        help=softwrap(
+            """
+            The name of the semgrep config file or directory, which will be discovered and used
+            hierarchically. If using a file, it must have the extension `.yaml` or `.yml`.
+
+            URLs and registry names are not supported.
+            """
+        ),
+    )
+
     args = ArgsListOption(
         example="--verbose",
         default=["--quiet"],