Refactor libclang parser and Reuse in unit rule

bazel/rules/rules_score/private/unit.bzl

@@ -19,12 +19,32 @@ following S-CORE process guidelines. A unit is the smallest testable
 software element with associated design, implementation, and tests.
 """
 
+load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
 load("@lobster//:lobster.bzl", "subrule_gtest_report")
+load("@rules_cc//cc:find_cc_toolchain.bzl", "use_cc_toolchain")
 load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
 load("@rules_rust//rust:defs.bzl", "rust_common")
 load("//bazel/rules/rules_score:providers.bzl", "CcDependencyInfo", "CertifiedScope", "SphinxSourcesInfo", "UnitDesignInfo", "UnitInfo")
+load("//cpp/libclang:cpp_parser.bzl", "cpp_parser_action_internal_attrs", "cpp_parser_target_aspects", "has_cpp_parser_inputs", "run_cpp_parser_action")
 load(":cc_dependency_aspect.bzl", "cc_dependencies_aspect")
 
+def _run_implementation_cpp_parser(ctx, impl, output_prefix):
+    return run_cpp_parser_action(
+        ctx,
+        target = impl,
+        output_prefix = output_prefix,
+        tool = ctx.attr._tool,
+        libclang = ctx.file._libclang,
+        llvm_cxx_builtin_include = ctx.attr._llvm_cxx_builtin_include,
+        llvm_extra_config_site = ctx.attr._llvm_extra_config_site,
+        log_level = ctx.attr._log_level[BuildSettingInfo].value,
+    )
+
+def _target_output_prefix(ctx, target):
+    package_name = target.label.package.replace("/", "_")
+    target_name = target.label.name.replace("/", "_")
+    return "{}_{}_{}".format(ctx.label.name, package_name, target_name)
+
 # ============================================================================
 # Private Rule Implementation
 # ============================================================================
@@ -59,28 +79,41 @@ def _unit_impl(ctx):
     design_static_fbs_depset = depset(transitive = design_static_fbs)
     design_dynamic_fbs_depset = depset(transitive = design_dynamic_fbs)
 
+    # Generate FBS files for implementation targets supported by the libclang parser.
+    implementation_class_fbs = []
+    collected_dependent_labels = []
+    for impl in ctx.attr.implementation:
+        if CcDependencyInfo in impl:
+            collected_dependent_labels.append(impl[CcDependencyInfo].dependencies)
+
+        if not has_cpp_parser_inputs(impl):
+            continue
+
+        output_prefix = _target_output_prefix(ctx, impl)
+        parser_outputs = _run_implementation_cpp_parser(ctx, impl, output_prefix)
+        implementation_class_fbs.append(parser_outputs.class_fbs)
+
     # Run each test executable via subrule_gtest_report and collect the XML outputs
     xml_files = []
     for test_target in ctx.attr.tests:
-        pkg = test_target.label.package.replace("/", "_")
-        test_name = test_target.label.name.replace("/", "_")
-        unique_name = "{}_{}_{}_gtest_report".format(ctx.label.name, pkg, test_name)
-        xml = subrule_gtest_report(unique_name, test_target.files_to_run.executable, test_target.default_runfiles.files)
+        unique_name = "{}_gtest_report".format(
+            _target_output_prefix(ctx, test_target),
+        )
+        xml = subrule_gtest_report(
+            unique_name,
+            test_target.files_to_run.executable,
+            test_target.default_runfiles.files,
+        )
         xml_files.append(xml)
 
     tests_depset = depset(xml_files)
 
     # Combine all files for DefaultInfo
     all_files = depset(
-        xml_files,
+        xml_files + implementation_class_fbs,
         transitive = [design_depset],
     )
 
-    collected_dependent_labels = []
-    for impl in ctx.attr.implementation:
-        if CcDependencyInfo in impl:
-            collected_dependent_labels.append(impl[CcDependencyInfo].dependencies)
-
     return [
         DefaultInfo(files = all_files),
         CertifiedScope(transitive_scopes = depset(ctx.attr.scope)),
@@ -103,32 +136,38 @@ def _unit_impl(ctx):
 # Rule Definition
 # ============================================================================
 
+_unit_attrs = {
+    "unit_design": attr.label_list(
+        mandatory = True,
+        providers = [UnitDesignInfo],
+        doc = "Unit design artifacts (unit_design targets only)",
+    ),
+    "implementation": attr.label_list(
+        mandatory = True,
+        providers = [[CcInfo], [rust_common.crate_info]],
+        aspects = [cc_dependencies_aspect] + cpp_parser_target_aspects(),
+        doc = "Implementation targets (cc_library, cc_binary, rust_library, rust_binary, etc.).",
+    ),
+    "scope": attr.string_list(
+        default = [],
+        doc = "Additional not explicitly named targets which are needed for the unit implementation",
+    ),
+    "tests": attr.label_list(
+        mandatory = True,
+        cfg = "exec",
+        doc = "Test targets that verify the unit (cc_test, py_test, rust_test, etc.)",
+    ),
+}
+
+_unit_attrs.update(cpp_parser_action_internal_attrs())
+
 _unit = rule(
     implementation = _unit_impl,
     doc = "Defines a software unit with design, implementation, and tests for S-CORE process compliance",
     subrules = [subrule_gtest_report],
-    attrs = {
-        "unit_design": attr.label_list(
-            mandatory = True,
-            providers = [UnitDesignInfo],
-            doc = "Unit design artifacts (unit_design targets only)",
-        ),
-        "implementation": attr.label_list(
-            mandatory = True,
-            providers = [[CcInfo], [rust_common.crate_info]],
-            aspects = [cc_dependencies_aspect],
-            doc = "Implementation targets (cc_library, cc_binary, rust_library, rust_binary, etc.)",
-        ),
-        "scope": attr.string_list(
-            default = [],
-            doc = "Additional not explicitly named targets which are needed for the unit implementation",
-        ),
-        "tests": attr.label_list(
-            mandatory = True,
-            cfg = "exec",
-            doc = "Test targets that verify the unit (cc_test, py_test, rust_test, etc.)",
-        ),
-    },
+    attrs = _unit_attrs,
+    toolchains = use_cc_toolchain(),
+    fragments = ["cpp"],
 )
 
 # ============================================================================

cpp/libclang/BUILD

@@ -32,9 +32,6 @@ rust_binary(
     data = [
         "@llvm_toolchain_llvm//:libclang",
     ],
-    env = {
-        "LIBCLANG_PATH": "$(rootpath @llvm_toolchain_llvm//:libclang)",
-    },
     visibility = ["//visibility:public"],
     deps = [
         "//cpp/libclang/src/utils",

cpp/libclang/README.md

@@ -26,7 +26,6 @@ cpp_parser(
   extra_args = [
   ],
   target = "//cpp/libclang/integration_test/cases/include_3rdparty",
-  tool = ":clang_rs_parser",
 )
 ```
 
@@ -38,9 +37,9 @@ Where:
 Expected result:
 
 - Bazel creates parser output artifact:
-  - `bazel-bin/cpp/libclang/cpp_parser_include_3rdparty_result.fbs.bin`
+  - `bazel-bin/cpp/libclang/cpp_parser_include_3rdparty_class_diagram.fbs.bin`
 - When `emit_debug_json = True`, the parser also writes:
-  - `bazel-bin/cpp/libclang/cpp_parser_include_3rdparty_result/debug.json`
+  - `bazel-bin/cpp/libclang/cpp_parser_include_3rdparty_debug.json`
 
 ## Configure debug logging
 
@@ -55,6 +54,6 @@ Accepted values are: `error`, `warn`, `info`, `debug`, `trace`.
 ## Quick check (optional)
 
 ```bash
-ls -l bazel-bin/cpp/libclang/cpp_parser_include_3rdparty_result.fbs.bin
-ls -l bazel-bin/cpp/libclang/cpp_parser_include_3rdparty_result/debug.json
+ls -l bazel-bin/cpp/libclang/integration_test/cases/include_3rdparty/parser_class_diagram.fbs.bin
+ls -l bazel-bin/cpp/libclang/integration_test/cases/include_3rdparty/parser_debug.json
 ```