kleaf: help: Support to query kernel_build targets

* Users can now run:
  * `tools/bazel help kleaf targets`
  * `tools/bazel help kleaf abi-targets`

  to get a list of available kernel_build and kernel_abi_update targets.

Bug: 256196368
Bug: 265138521
Change-Id: I26e39fa146e2f856dd102bf4c3115e088c6ae380
Signed-off-by: Ulises Mendez Martinez <umendez@google.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/kleaf/bazel.py b/kleaf/bazel.py
index 70a44fa..6f9e832 100755
--- a/kleaf/bazel.py
+++ b/kleaf/bazel.py
@@ -41,6 +41,17 @@ _CONFIG_PATTERN = re.compile(
     r"^--config=(?P<config>[a-z_]+):\s*(?P<description>.*)$"
 )
 
+# Sync with the following files:
+#   kleaf/impl/kernel_build.bzl
+_QUERY_TARGETS_ARG = 'kind("kernel_build rule", //... except attr("tags", \
+    "manual", //...) except //.source_date_epoch_dir/... except //out/...)'
+
+# Sync with the following files:
+#   kleaf/impl/abi/abi_update.bzl
+#   kleaf/impl/abi/kernel_abi.bzl
+_QUERY_ABI_TARGETS_ARG = 'kind("(update_source_file|abi_update) rule", //... except attr("tags", \
+    "manual", //...) except //.source_date_epoch_dir/... except //out/...)'
+
 
 def _require_absolute_path(p: str) -> pathlib.Path:
     p = pathlib.Path(p)
@@ -106,6 +117,7 @@ class BazelWrapper(object):
 
         self._parse_startup_options()
         self._parse_command_args()
+        self._rebuild_kleaf_help_args()
 
     def _add_startup_option_to_parser(self, parser):
         group = parser.add_argument_group(
@@ -361,6 +373,21 @@ class BazelWrapper(object):
                 f"{self.root_dir}/{_BAZEL_RC_DIR}/{f}")
             bazelrc_parser.add_to(config_group, root_dir=self.root_dir)
 
+        # Additional helper queries for target discovery.
+        kleaf_group = parser.add_argument_group(
+            title=textwrap.dedent("""\
+                                  Kleaf Help - Query commands.
+                                  Usage: bazel help kleaf [<command>]"""),
+        )
+        kleaf_group.add_argument(
+            "targets",
+            help = "List kernel_build targets under current WORKSPACE",
+        )
+        kleaf_group.add_argument(
+            "abi_targets",
+            help = "List ABI related targets under current WORKSPACE",
+        )
+
         parser.add_argument_group(
             title="Target patterns",
             description="$ bazel help target-syntax"
@@ -391,6 +418,37 @@ class BazelWrapper(object):
         else:
             print("Native bazel help menu:")
 
+    # Handle queries of kernel_build and kernel_abi_update targets.
+    def _rebuild_kleaf_help_args(self):
+        show_kleaf_targets = self.command == "help" and self.transformed_command_args and \
+            self.transformed_command_args[0] == "kleaf" and \
+            len(self.transformed_command_args) > 1  and \
+            (self.transformed_command_args[1] in ["targets", "abi-targets", "abi_targets"])
+
+        if not show_kleaf_targets:
+            return
+
+        # Transform the command to a query
+        self.command = "query"
+        _kleaf_help_command = self.transformed_command_args[1]
+        # Inform about the ignored arguments if any.
+        _ignored_args = self.transformed_command_args[2:]
+        if _ignored_args:
+            print("INFO: Ignoring arguments:", _ignored_args)
+        # Suppress errors from malformed packages. e.g. clang packages with
+        #   Soong dependencies, //external packages, etc.
+        self.transformed_command_args = [
+            "--keep_going",
+            "--ui_event_filters=-error",
+            "--noshow_progress"
+        ]
+        if _kleaf_help_command == "targets":
+            print("Kleaf available targets:")
+            self.transformed_command_args.append(_QUERY_TARGETS_ARG)
+        else:
+            print("Kleaf ABI update available targets:")
+            self.transformed_command_args.append(_QUERY_ABI_TARGETS_ARG)
+
     def run(self):
         final_args = self._build_final_args()