Support running pants from anywhere in the project. (pantsbuild#18412)

Allows the use of `pants` from anywhere in a project, not just the
project root, while also respecting specs on the command line relative
to `CWD` rather than the build root.

Closes pantsbuild#6750

src/python/pants/base/specs_parser.py

@@ -44,8 +44,17 @@ class SpecsParser:
     class BadSpecError(Exception):
         """Indicates an unparseable command line selector."""
 
-    def __init__(self, root_dir: str | None = None) -> None:
+    def __init__(self, *, root_dir: str | None = None, working_dir: str | None = None) -> None:
         self._root_dir = os.path.realpath(root_dir or get_buildroot())
+        self._working_dir = (
+            os.path.relpath(os.path.join(self._root_dir, working_dir), self._root_dir)
+            if working_dir
+            else ""
+        )
+        if self._working_dir.startswith(".."):
+            raise self.BadSpecError(
+                f"Work directory {self._working_dir} escapes build root {self._root_dir}"
+            )
 
     def _normalize_spec_path(self, path: str) -> str:
         is_abs = not path.startswith("//") and os.path.isabs(path)
@@ -58,9 +67,15 @@ def _normalize_spec_path(self, path: str) -> str:
         else:
             if path.startswith("//"):
                 path = path[2:]
+            elif self._working_dir:
+                path = os.path.join(self._working_dir, path)
             path = os.path.join(self._root_dir, path)
 
         normalized = os.path.relpath(path, self._root_dir)
+        if normalized.startswith(".."):
+            raise self.BadSpecError(
+                f"Relative spec path {path} escapes build root {self._root_dir}"
+            )
         if normalized == ".":
             normalized = ""
         return normalized

src/python/pants/base/specs_parser_test.py

@@ -52,8 +52,10 @@ def file_glob(val: str) -> FileGlobSpec:
     return FileGlobSpec(val)
 
 
-def assert_spec_parsed(build_root: Path, spec_str: str, expected_spec: Spec) -> None:
-    parser = SpecsParser(str(build_root))
+def assert_spec_parsed(
+    build_root: Path, spec_str: str, expected_spec: Spec, working_dir: str | None = None
+) -> None:
+    parser = SpecsParser(root_dir=str(build_root), working_dir=working_dir)
     spec, is_ignore = parser.parse_spec(spec_str)
     assert isinstance(spec, type(expected_spec))
     assert spec == expected_spec
@@ -241,3 +243,29 @@ def test_cmd_line_affordances_absolute_path(
 ) -> None:
     spec = os.path.join(tmp_path, spec_suffix)
     assert_spec_parsed(tmp_path, spec, expected)
+
+
+@pytest.mark.parametrize(
+    "working_dir, spec, expected",
+    [
+        ("a/b", "c", dir_literal("a/b/c")),
+        ("a/b", "../d", dir_literal("a/d")),
+        ("a/b", "//e", dir_literal("e")),
+    ],
+)
+def test_working_dir(tmp_path: Path, working_dir: str, spec: str, expected: Spec) -> None:
+    assert_spec_parsed(tmp_path, spec, expected, working_dir)
+    assert_spec_parsed(tmp_path, spec, expected, str(tmp_path / working_dir))
+
+
+def test_invalid_working_dir(tmp_path: Path) -> None:
+    with pytest.raises(SpecsParser.BadSpecError):
+        assert_spec_parsed(tmp_path, "../../foo", dir_literal("foo"), "a")
+    with pytest.raises(SpecsParser.BadSpecError):
+        assert_spec_parsed(tmp_path, "../../foo", dir_literal("foo"), str(tmp_path / "a"))
+    with pytest.raises(SpecsParser.BadSpecError):
+        assert_spec_parsed(tmp_path, "test_invalid_working_dir0/foo", dir_literal("foo"), "..")
+    with pytest.raises(SpecsParser.BadSpecError):
+        assert_spec_parsed(
+            tmp_path, "test_invalid_working_dir0/foo", dir_literal("foo"), str(tmp_path / "..")
+        )

src/python/pants/bin/daemon_pants_runner.py

@@ -99,6 +99,7 @@ def single_daemonized_run(
         self,
         args: Tuple[str, ...],
         env: Dict[str, str],
+        working_dir: str,
         cancellation_latch: PySessionCancellationLatch,
     ) -> ExitCode:
         """Run a single daemonized run of Pants.
@@ -110,6 +111,8 @@ def single_daemonized_run(
 
         try:
             logger.debug("Connected to pantsd")
+            logger.debug(f"work dir: {working_dir}")
+
             # Capture the client's start time, which we propagate here in order to get an accurate
             # view of total time.
             env_start_time = env.get("PANTSD_RUNTRACKER_CLIENT_START_TIME", None)
@@ -130,6 +133,7 @@ def single_daemonized_run(
             scheduler, options_initializer = self._core.prepare(options_bootstrapper, complete_env)
             runner = LocalPantsRunner.create(
                 complete_env,
+                working_dir,
                 options_bootstrapper,
                 scheduler=scheduler,
                 options_initializer=options_initializer,
@@ -148,6 +152,7 @@ def __call__(
         command: str,
         args: Tuple[str, ...],
         env: Dict[str, str],
+        working_dir: str,
         cancellation_latch: PySessionCancellationLatch,
         stdin_fileno: int,
         stdout_fileno: int,
@@ -169,6 +174,8 @@ def __call__(
                     stdout_fileno=stdout_fileno,
                     stderr_fileno=stderr_fileno,
                 ):
-                    return self.single_daemonized_run(((command,) + args), env, cancellation_latch)
+                    return self.single_daemonized_run(
+                        ((command,) + args), env, working_dir, cancellation_latch
+                    )
             finally:
                 logger.info(f"request completed: `{' '.join(args)}`")

src/python/pants/bin/local_pants_runner.py

@@ -58,11 +58,13 @@ class LocalPantsRunner:
     executor: PyExecutor
     union_membership: UnionMembership
     is_pantsd_run: bool
+    working_dir: str
 
     @classmethod
     def create(
         cls,
         env: CompleteEnvironmentVars,
+        working_dir: str,
         options_bootstrapper: OptionsBootstrapper,
         options_initializer: OptionsInitializer | None = None,
         scheduler: GraphScheduler | None = None,
@@ -150,6 +152,7 @@ def create(
             options_bootstrapper=options_bootstrapper,
             options=options,
             session=graph_session.scheduler_session,
+            working_dir=working_dir,
         )
 
         return cls(
@@ -163,6 +166,7 @@ def create(
             executor=executor,
             union_membership=union_membership,
             is_pantsd_run=is_pantsd_run,
+            working_dir=working_dir,
         )
 
     def _perform_run(self, goals: tuple[str, ...]) -> ExitCode:
@@ -237,7 +241,7 @@ def _run_inner(self) -> ExitCode:
             return PANTS_FAILED_EXIT_CODE
 
     def run(self, start_time: float) -> ExitCode:
-        spec_parser = SpecsParser()
+        spec_parser = SpecsParser(working_dir=self.working_dir)
         specs = []
         for spec_str in self.options.specs:
             spec, is_ignore = spec_parser.parse_spec(spec_str)

src/python/pants/bin/pants_loader.py

@@ -103,7 +103,6 @@ def main(cls) -> None:
         sys.setrecursionlimit(int(os.environ.get(RECURSION_LIMIT, "10000")))
 
         entrypoint = os.environ.pop(DAEMON_ENTRYPOINT, None)
-
         if entrypoint:
             cls.run_alternate_entrypoint(entrypoint)
         else:

src/python/pants/bin/pants_runner.py

@@ -97,6 +97,8 @@ def run(self, start_time: float) -> ExitCode:
                 log_location=init_workdir(global_bootstrap_options), pantsd_instance=False
             )
             runner = LocalPantsRunner.create(
-                env=CompleteEnvironmentVars(self.env), options_bootstrapper=options_bootstrapper
+                env=CompleteEnvironmentVars(self.env),
+                working_dir=os.getcwd(),
+                options_bootstrapper=options_bootstrapper,
             )
             return runner.run(start_time)

src/python/pants/engine/internals/graph_test.py

@@ -919,7 +919,7 @@ def assert_generated(
     if expected_dependencies is not None:
         # TODO: Adjust the `TransitiveTargets` API to expose the complete mapping.
         #   see https://github.com/pantsbuild/pants/issues/11270
-        specs = SpecsParser(rule_runner.build_root).parse_specs(
+        specs = SpecsParser(root_dir=rule_runner.build_root).parse_specs(
             ["::"], description_of_origin="tests"
         )
         addresses = rule_runner.request(Addresses, [specs])

src/python/pants/engine/internals/native_engine.pyi

@@ -246,6 +246,7 @@ class RawFdRunner(Protocol):
         command: str,
         args: tuple[str, ...],
         env: dict[str, str],
+        working_dir: str,
         cancellation_latch: PySessionCancellationLatch,
         stdin_fileno: int,
         stdout_fileno: int,

src/python/pants/engine/internals/specs_rules_test.py

@@ -633,7 +633,7 @@ def test_resolve_addresses_from_raw_specs(rule_runner: RuleRunner) -> None:
         "address_spec:nonfile#gen",
     ]
     multiple_files_specs = ["multiple_files/f2.txt", "multiple_files:multiple_files"]
-    specs = SpecsParser(rule_runner.build_root).parse_specs(
+    specs = SpecsParser(root_dir=rule_runner.build_root).parse_specs(
         [*no_interaction_specs, *multiple_files_specs],
         description_of_origin="tests",
     )

src/python/pants/init/specs_calculator.py

@@ -29,11 +29,12 @@ def calculate_specs(
     options_bootstrapper: OptionsBootstrapper,
     options: Options,
     session: SchedulerSession,
+    working_dir: str,
 ) -> Specs:
     """Determine the specs for a given Pants run."""
     global_options = options.for_global_scope()
     unmatched_cli_globs = global_options.unmatched_cli_globs
-    specs = SpecsParser().parse_specs(
+    specs = SpecsParser(working_dir=working_dir).parse_specs(
         options.specs,
         description_of_origin="CLI arguments",
         unmatched_glob_behavior=unmatched_cli_globs,

src/python/pants/testutil/rule_runner.py

@@ -416,7 +416,7 @@ def run_goal_rule(
             [GlobalOptions.get_scope_info(), goal.subsystem_cls.get_scope_info()],
             self.union_membership,
         ).specs
-        specs = SpecsParser(self.build_root).parse_specs(
+        specs = SpecsParser(root_dir=self.build_root).parse_specs(
             raw_specs, description_of_origin="RuleRunner.run_goal_rule()"
         )
 

src/rust/engine/src/externs/interface.rs

@@ -559,6 +559,7 @@ fn nailgun_server_create(
         exe.cmd.command,
         PyTuple::new(py, exe.cmd.args),
         exe.cmd.env.into_iter().collect::<HashMap<String, String>>(),
+        exe.cmd.working_dir,
         PySessionCancellationLatch(exe.cancelled),
         exe.stdin_fd as i64,
         exe.stdout_fd as i64,