pw_build: Add check_includes to generated GN

This CL extends generate_3p_gn.py to allow specifying a list of targets
that should have `check_includes = false` applied to them.

See also:
https://gn.googlesource.com/gn/+/main/docs/reference.md#var_check_includes

Change-Id: Ib15fa38017407ec10385db497b3849f53e93ef62
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/146591
Commit-Queue: Aaron Green <[email protected]>
Reviewed-by: Taylor Cramer <[email protected]>

pw_build/docs.rst

@@ -248,6 +248,15 @@ describe a single JSON object, with the following fields:
 
      "allow_testonly": true
 
+* ``no_gn_check``: List of Bazel targets that violate ``gn check``'s
+  `rules`__. Third-party targets that do not conform can be excluded.
+
+  .. code-block::
+
+     "no_gn_check": [ "//fuzztest:regexp_dfa" ]
+
+.. __: https://gn.googlesource.com/gn/+/main/docs/reference.md#cmd_check
+
 Python packages
 ---------------
 GN templates for :ref:`Python build automation <docs-python-build>` are

pw_build/py/generate_3p_gn_test.py

@@ -264,6 +264,7 @@ def test_write_build_gn(self):
         """Tests writing a complete BUILD.gn file."""
         generator = GnGenerator()
         generator.set_repo('test')
+        generator.exclude_from_gn_check(bazel='//bar:target3')
 
         generator.add_configs(
             '',
@@ -485,6 +486,7 @@ def test_write_build_gn(self):
 
 # Generated from //bar:target3
 pw_source_set("target3") {
+  check_includes = false
   cflags = [
     "bar-flag",
   ]

pw_build/py/pw_build/generate_3p_gn.py

@@ -106,6 +106,7 @@ def __init__(self) -> None:
         self._repo: str
         self._repo_var: str
         self._repos: Dict[str, Set[str]] = defaultdict(set)
+        self._no_gn_check: List[GnLabel] = []
         self.configs: Dict[str, List[GnConfig]] = defaultdict(list)
         self.targets: Dict[str, List[GnTarget]] = defaultdict(list)
 
@@ -127,6 +128,16 @@ def set_repo(self, repo: str) -> None:
         self._base_label = GnLabel(f'$dir_pw_third_party/{repo}')
         self._base_path = GnPath(f'$dir_pw_third_party_{self._repo_var}')
 
+    def exclude_from_gn_check(self, **kwargs) -> None:
+        """Mark a target as being excluding from `gn check`.
+
+        This should be called before loading or adding targets.
+
+        Args:
+            kwargs: Same as `GnLabel`.
+        """
+        self._no_gn_check.append(GnLabel(self._base_label, **kwargs))
+
     def load_workspace(self, workspace_path: Path) -> str:
         """Loads a Bazel workspace.
 
@@ -137,7 +148,7 @@ def load_workspace(self, workspace_path: Path) -> str:
         self.set_repo(self._workspace.repo)
         return self._repo
 
-    def loadtargets(self, kind: str, allow_testonly: bool) -> None:
+    def load_targets(self, kind: str, allow_testonly: bool) -> None:
         """Analyzes a Bazel workspace and loads target info from it.
 
         Target info will only be added for `kind` rules. Additionally,
@@ -161,6 +172,7 @@ def add_target(self, allow_testonly: bool = False, **kwargs) -> None:
             Same as `GnTarget`.
         """
         target = GnTarget(self._base_label.dir(), self._base_path, **kwargs)
+        target.check_includes = target.label() not in self._no_gn_check
         if allow_testonly or not target.testonly:
             package = target.package()
             self.packages.add(package)
@@ -262,6 +274,7 @@ def write_build_gn(self, package: str, build_gn: GnWriter) -> None:
         Args:
             package: The name of the package to write a BUILD.gn for.
             build_gn: The output writer object.
+            no_gn_check: List of targets with `check_includes = false`.
         """
         build_gn.write_imports(['//build_overrides/pigweed.gni'])
         build_gn.write_blank()
@@ -391,8 +404,11 @@ def _generate_gn(workspace_path: Path) -> None:
         add_configs = obj.get('add', [])
         removeconfigs = obj.get('remove', [])
         allow_testonly = obj.get('allow_testonly', False)
+        no_gn_check = obj.get('no_gn_check', [])
 
-    generator.loadtargets('cc_library', allow_testonly)
+    for exclusion in no_gn_check:
+        generator.exclude_from_gn_check(bazel=exclusion)
+    generator.load_targets('cc_library', allow_testonly)
     generator.generate_configs(add_configs, removeconfigs)
 
     with GnFile(Path(output, f'{repo}.gni')) as repo_gni:

pw_build/py/pw_build/gn_target.py

@@ -57,6 +57,7 @@ def __init__(
         base_path: Union[str, PurePosixPath, GnPath],
         bazel: Optional[BazelRule] = None,
         json: Optional[str] = None,
+        check_includes: bool = True,
     ) -> None:
         """Creates a GN target
 
@@ -70,6 +71,7 @@ def __init__(
         self._repos: Set[str] = set()
         self.visibility: List[GnVisibility] = []
         self.testonly: bool = False
+        self.check_includes = check_includes
         self.public: List[GnPath] = []
         self.sources: List[GnPath] = []
         self.inputs: List[GnPath] = []
@@ -167,6 +169,7 @@ def _from_json(self, data: str) -> None:
             for scope in obj.get('visibility', [])
         ]
         self.testonly = bool(obj.get('testonly', False))
+        self.testonly = bool(obj.get('check_includes', False))
         self.public = [GnPath(path) for path in obj.get('public', [])]
         self.sources = [GnPath(path) for path in obj.get('sources', [])]
         self.inputs = [GnPath(path) for path in obj.get('inputs', [])]
@@ -193,6 +196,8 @@ def to_json(self) -> str:
             obj['visibility'] = [str(scope) for scope in self.visibility]
         if self.testonly:
             obj['testonly'] = self.testonly
+        if not self.check_includes:
+            obj['check_includes'] = self.check_includes
         if self.public:
             obj['public'] = [str(path) for path in self.public]
         if self.sources:
@@ -222,6 +227,10 @@ def name(self) -> str:
         """Returns the target name."""
         return self._label.name()
 
+    def label(self) -> GnLabel:
+        """Returns the target label."""
+        return self._label
+
     def type(self) -> str:
         """Returns the target type."""
         return self._type

pw_build/py/pw_build/gn_writer.py

@@ -132,6 +132,8 @@ def write_target(self, target: GnTarget) -> None:
         visibility = [target.make_relative(scope) for scope in scopes]
         self.write_list('visibility', visibility)
 
+        if not target.check_includes:
+            self.write('check_includes = false')
         self.write_list('public', [str(path) for path in target.public])
         self.write_list('sources', [str(path) for path in target.sources])
         self.write_list('inputs', [str(path) for path in target.inputs])

third_party/fuzztest/repo.json

@@ -22,5 +22,6 @@
         "$dir_pw_toolchain/host_clang:sanitize_undefined_heuristic",
         "$dir_pw_toolchain/host_clang:sanitize_thread"
     ],
-    "allow_testonly": true
+    "allow_testonly": true,
+    "no_gn_check": [ "//fuzztest:regexp_dfa" ]
 }