Fix load("//tools/cpp:cc_toolchain_config_lib.bzl") to load("@bazel_tools//tools/cpp:cc_toolchain_config_lib.bzl")

And add a test checking the full output from the migrator for a simple CROSSTOOL.

Issue #5380
RELNOTES: None.
PiperOrigin-RevId: 239153961

tools/migration/crosstool_to_starlark_lib.go

@@ -27,7 +27,7 @@ type CToolchainIdentifier struct {
 
 // Writes the load statement for the cc_toolchain_config_lib
 func getCcToolchainConfigHeader() string {
-	return `load("//tools/cpp:cc_toolchain_config_lib.bzl",
+	return `load("@bazel_tools//tools/cpp:cc_toolchain_config_lib.bzl",
     "action_config",
     "artifact_name_pattern",
     "env_entry",

tools/migration/crosstool_to_starlark_lib_test.go

@@ -1530,3 +1530,150 @@ func TestFeatureDeclaration(t *testing.T) {
 		}
 	}
 }
+
+func TestRule(t *testing.T) {
+	simpleToolchain := getSimpleCToolchain("simple")
+	expected := `load("@bazel_tools//tools/cpp:cc_toolchain_config_lib.bzl",
+    "action_config",
+    "artifact_name_pattern",
+    "env_entry",
+    "env_set",
+    "feature",
+    "feature_set",
+    "flag_group",
+    "flag_set",
+    "make_variable",
+    "tool",
+    "tool_path",
+    "variable_with_value",
+    "with_feature_set",
+)
+load("@bazel_tools//tools/build_defs/cc:action_names.bzl", "ACTION_NAMES")
+
+def _impl(ctx):
+    toolchain_identifier = "id-simple"
+
+    host_system_name = "host-simple"
+
+    target_system_name = "target-simple"
+
+    target_cpu = "cpu-simple"
+
+    target_libc = "libc-simple"
+
+    compiler = "compiler-simple"
+
+    abi_version = "version-simple"
+
+    abi_libc_version = "libc_version-simple"
+
+    cc_target_os = None
+
+    builtin_sysroot = None
+
+    all_compile_actions = [
+        ACTION_NAMES.c_compile,
+        ACTION_NAMES.cpp_compile,
+        ACTION_NAMES.linkstamp_compile,
+        ACTION_NAMES.assemble,
+        ACTION_NAMES.preprocess_assemble,
+        ACTION_NAMES.cpp_header_parsing,
+        ACTION_NAMES.cpp_module_compile,
+        ACTION_NAMES.cpp_module_codegen,
+        ACTION_NAMES.clif_match,
+        ACTION_NAMES.lto_backend,
+    ]
+
+    all_cpp_compile_actions = [
+        ACTION_NAMES.cpp_compile,
+        ACTION_NAMES.linkstamp_compile,
+        ACTION_NAMES.cpp_header_parsing,
+        ACTION_NAMES.cpp_module_compile,
+        ACTION_NAMES.cpp_module_codegen,
+        ACTION_NAMES.clif_match,
+    ]
+
+    preprocessor_compile_actions = [
+        ACTION_NAMES.c_compile,
+        ACTION_NAMES.cpp_compile,
+        ACTION_NAMES.linkstamp_compile,
+        ACTION_NAMES.preprocess_assemble,
+        ACTION_NAMES.cpp_header_parsing,
+        ACTION_NAMES.cpp_module_compile,
+        ACTION_NAMES.clif_match,
+    ]
+
+    codegen_compile_actions = [
+        ACTION_NAMES.c_compile,
+        ACTION_NAMES.cpp_compile,
+        ACTION_NAMES.linkstamp_compile,
+        ACTION_NAMES.assemble,
+        ACTION_NAMES.preprocess_assemble,
+        ACTION_NAMES.cpp_module_codegen,
+        ACTION_NAMES.lto_backend,
+    ]
+
+    all_link_actions = [
+        ACTION_NAMES.cpp_link_executable,
+        ACTION_NAMES.cpp_link_dynamic_library,
+        ACTION_NAMES.cpp_link_nodeps_dynamic_library,
+    ]
+
+    action_configs = []
+
+    features = []
+
+    cxx_builtin_include_directories = []
+
+    artifact_name_patterns = []
+
+    make_variables = []
+
+    tool_paths = []
+
+
+    out = ctx.actions.declare_file(ctx.label.name)
+    ctx.actions.write(out, "Fake executable")
+    return [
+        cc_common.create_cc_toolchain_config_info(
+            ctx = ctx,
+            features = features,
+            action_configs = action_configs,
+            artifact_name_patterns = artifact_name_patterns,
+            cxx_builtin_include_directories = cxx_builtin_include_directories,
+            toolchain_identifier = toolchain_identifier,
+            host_system_name = host_system_name,
+            target_system_name = target_system_name,
+            target_cpu = target_cpu,
+            target_libc = target_libc,
+            compiler = compiler,
+            abi_version = abi_version,
+            abi_libc_version = abi_libc_version,
+            tool_paths = tool_paths,
+            make_variables = make_variables,
+            builtin_sysroot = builtin_sysroot,
+            cc_target_os = cc_target_os
+        ),
+        DefaultInfo(
+            executable = out,
+        ),
+    ]
+cc_toolchain_config =  rule(
+    implementation = _impl,
+    attrs = {
+        "cpu": attr.string(mandatory=True, values=["cpu-simple"]),
+    },
+    provides = [CcToolchainConfigInfo],
+    executable = True,
+)
+`
+	crosstool := makeCrosstool([]string{simpleToolchain})
+	got, err := Transform(crosstool)
+	if err != nil {
+		t.Fatalf("CROSSTOOL conversion failed: %v", err)
+	}
+	if got != expected {
+		t.Fatalf("Expected:\n%v\nGot:\n%v\nTested CROSSTOOL:\n%v",
+			expected, got, simpleToolchain)
+	}
+}