Use configured tools for ThinLTO indexing

cc/private/link/finalize_link_action.bzl

@@ -230,7 +230,7 @@ def finalize_link_action(
     else:
         tool_path = _cc_common_internal.get_tool_for_action(
             feature_configuration = feature_configuration,
-            action_name = link_type.action_name,
+            action_name = action_name,
         )
 
     if link_type.linker_or_archiver == USE_ARCHIVER:

cc/toolchains/legacy_file_group.bzl

@@ -42,6 +42,9 @@ LEGACY_FILE_GROUPS = {
         Label("//cc/toolchains/actions:cpp_link_nodeps_dynamic_library"),
         Label("//cc/toolchains/actions:cpp_link_executable"),
         Label("//cc/toolchains/actions:generate_def_file"),
+        Label("//cc/toolchains/actions:lto_index_for_dynamic_library"),
+        Label("//cc/toolchains/actions:lto_index_for_executable"),
+        Label("//cc/toolchains/actions:lto_index_for_nodeps_dynamic_library"),
     ],
     "objcopy_files": [
         Label("//cc/toolchains/actions:objcopy_embed_data"),

tests/cc/common/cc_binary_thin_lto_tests.bzl

@@ -4,6 +4,7 @@ load("@bazel_features//:features.bzl", "bazel_features")
 load("@rules_testing//lib:analysis_test.bzl", "test_suite")
 load("@rules_testing//lib:truth.bzl", "matching", "subjects")
 load("@rules_testing//lib:util.bzl", "TestingAspectInfo", "util")
+load("//cc:action_names.bzl", "ACTION_NAMES")
 load("//cc:cc_binary.bzl", _actual_cc_binary = "cc_binary")
 load("//cc:cc_library.bzl", "cc_library")
 load("//cc:cc_test.bzl", _actual_cc_test = "cc_test")
@@ -176,6 +177,31 @@ def _test_thin_lto_action_graph_impl(env, target):
         ),
     )
 
+def _test_thin_lto_index_uses_its_action_tool(name, **kwargs):
+    util.helper_target(
+        cc_binary,
+        name = name + "/bin",
+        srcs = ["hello.cc"],
+    )
+    cc_analysis_test(
+        name = name,
+        impl = _test_thin_lto_index_uses_its_action_tool_impl,
+        target = name + "/bin",
+        test_features = ["thin_lto", "supports_start_end_lib"],
+        with_action_configs = [
+            ACTION_NAMES.cpp_link_executable,
+            ACTION_NAMES.lto_index_for_executable,
+        ],
+        **kwargs
+    )
+
+def _test_thin_lto_index_uses_its_action_tool_impl(env, target):
+    index_action = env.expect.that_target(target).action_named("CppLTOIndexing")
+    env.expect.that_str(index_action.actual.argv[0]).equals("tests/cc/testutil/toolchains/lto_index_tool")
+
+    link_action = env.expect.that_target(target).action_named("CppLink")
+    env.expect.that_str(link_action.actual.argv[0]).equals("tests/cc/testutil/toolchains/link_executable_tool")
+
 def _test_thin_lto_linkshared(name, **kwargs):
     util.helper_target(
         cc_library,
@@ -2345,6 +2371,7 @@ def cc_binary_thin_lto_tests(name):
 
     # These tests fail on Bazel 7 and 8, run only for Bazel 9+.
     if bazel_features.cc.cc_common_is_in_rules_cc:
+        tests.append(_test_thin_lto_index_uses_its_action_tool)
         tests.append(_test_thin_lto_linkshared)
         tests.append(_test_thin_lto_backend_env)
         tests.append(_test_linkstatic_cc_test)

tests/cc/testutil/toolchains/cc_toolchain_config.bzl

@@ -1900,7 +1900,9 @@ _action_name_to_action = {
 }
 
 _tool_for_action_config = {
+    "c++-link-executable": "link_executable_tool",
     "generate-def-file": "def_parser_tool",
+    "lto-index-for-executable": "lto_index_tool",
     "objcopy_embed_data": "objcopy_embed_data_tool",
     "ld_embed_data": "ld_embed_data_tool",
 }

tests/rule_based_toolchain/toolchain_config/toolchain_config_test.bzl

@@ -27,6 +27,7 @@ load(
 )
 load("//cc/toolchains:cc_toolchain_config_info.bzl", "CcToolchainConfigInfo")
 load("//cc/toolchains:cc_toolchain_info.bzl", "ActionTypeInfo", "ToolchainConfigInfo")
+load("//cc/toolchains:legacy_file_group.bzl", "LEGACY_FILE_GROUPS")
 load("//cc/toolchains/impl:legacy_converter.bzl", "convert_toolchain")
 load("//cc/toolchains/impl:toolchain_config_info.bzl", _toolchain_config_info = "toolchain_config_info")
 load("//tests/rule_based_toolchain:helpers.bzl", "path_pattern")
@@ -277,6 +278,13 @@ def _toolchain_collects_files_test(env, targets):
         ),
     ]).in_order()
 
+def _thin_lto_index_actions_are_linker_files_test(env, _targets):
+    env.expect.that_collection(LEGACY_FILE_GROUPS["linker_files"]).contains_at_least([
+        Label("//cc/toolchains/actions:lto_index_for_dynamic_library"),
+        Label("//cc/toolchains/actions:lto_index_for_executable"),
+        Label("//cc/toolchains/actions:lto_index_for_nodeps_dynamic_library"),
+    ])
+
 def _tool_env_wires_into_toolchain_test(env, targets):
     tc = env.expect.that_target(targets.tool_env_toolchain_config).provider(ToolchainConfigInfo)
     legacy = convert_toolchain(tc.actual)
@@ -395,6 +403,7 @@ TESTS = {
     "args_missing_requirements_invalid_test": _args_missing_requirements_invalid_test,
     "args_requiring_capability_valid_test": _args_requiring_capability_valid_test,
     "toolchain_collects_files_test": _toolchain_collects_files_test,
+    "thin_lto_index_actions_are_linker_files_test": _thin_lto_index_actions_are_linker_files_test,
     "tool_env_wires_into_toolchain_test": _tool_env_wires_into_toolchain_test,
     "legacy_tools_produce_tool_paths_test": _legacy_tools_produce_tool_paths_test,
     "rules_based_cc_toolchain_returns_cc_toolchain_config_info_test": _rules_based_cc_toolchain_returns_cc_toolchain_config_info_test,