carbon-lang/bazel/cc_toolchains/cc_toolchain_linking.bzl

# Part of the Carbon Language project, under the Apache License v2.0 with LLVM
# Exceptions. See /LICENSE for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

"""Definitions of linking related features used in a `cc_toolchain_config`."""

load("@rules_cc//cc:action_names.bzl", "ACTION_NAMES")
load(
    "@rules_cc//cc:cc_toolchain_config_lib.bzl",
    "feature",
    "flag_group",
    "flag_set",
    "variable_with_value",
)
load(
    ":cc_toolchain_actions.bzl",
    "all_link_actions",
)

default_link_libraries_feature = feature(
    name = "default_link_libraries",
    enabled = True,
    flag_sets = [flag_set(
        actions = all_link_actions,
        flag_groups = [
            flag_group(
                expand_if_available = "linkstamp_paths",
                flags = ["%{linkstamp_paths}"],
                iterate_over = "linkstamp_paths",
            ),
            flag_group(
                expand_if_available = "libraries_to_link",
                flag_groups = [
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file_group",
                        ),
                        flags = ["-Wl,--start-lib"],
                    ),
                    flag_group(
                        expand_if_true = "libraries_to_link.is_whole_archive",
                        flags = ["-Wl,-whole-archive"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file_group",
                        ),
                        flags = ["%{libraries_to_link.object_files}"],
                        iterate_over = "libraries_to_link.object_files",
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file",
                        ),
                        flags = ["%{libraries_to_link.name}"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "interface_library",
                        ),
                        flags = ["%{libraries_to_link.name}"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "static_library",
                        ),
                        flags = ["%{libraries_to_link.name}"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "dynamic_library",
                        ),
                        flags = ["-l%{libraries_to_link.name}"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "versioned_dynamic_library",
                        ),
                        flags = ["-l:%{libraries_to_link.name}"],
                    ),
                    flag_group(
                        expand_if_true = "libraries_to_link.is_whole_archive",
                        flags = ["-Wl,-no-whole-archive"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file_group",
                        ),
                        flags = ["-Wl,--end-lib"],
                    ),
                ],
                iterate_over = "libraries_to_link",
            ),
            # Note that the params file comes at the end, after the
            # libraries to link above.
            flag_group(
                expand_if_available = "linker_param_file",
                flags = ["@%{linker_param_file}"],
            ),
        ],
    )],
)

macos_link_libraries_feature = feature(
    name = "macos_link_libraries",
    enabled = True,
    flag_sets = [flag_set(
        actions = all_link_actions,
        flag_groups = [
            flag_group(
                expand_if_available = "linkstamp_paths",
                flags = ["%{linkstamp_paths}"],
                iterate_over = "linkstamp_paths",
            ),
            flag_group(
                expand_if_available = "libraries_to_link",
                flag_groups = [
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file_group",
                        ),
                        flags = ["-Wl,--start-lib"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file_group",
                        ),
                        flag_groups = [
                            flag_group(
                                expand_if_false = "libraries_to_link.is_whole_archive",
                                flags = ["%{libraries_to_link.object_files}"],
                            ),
                            flag_group(
                                expand_if_true = "libraries_to_link.is_whole_archive",
                                flags = ["-Wl,-force_load,%{libraries_to_link.object_files}"],
                            ),
                        ],
                        iterate_over = "libraries_to_link.object_files",
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file",
                        ),
                        flag_groups = [
                            flag_group(
                                expand_if_false = "libraries_to_link.is_whole_archive",
                                flags = ["%{libraries_to_link.name}"],
                            ),
                            flag_group(
                                expand_if_true = "libraries_to_link.is_whole_archive",
                                flags = ["-Wl,-force_load,%{libraries_to_link.name}"],
                            ),
                        ],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "interface_library",
                        ),
                        flag_groups = [
                            flag_group(
                                expand_if_false = "libraries_to_link.is_whole_archive",
                                flags = ["%{libraries_to_link.name}"],
                            ),
                            flag_group(
                                expand_if_true = "libraries_to_link.is_whole_archive",
                                flags = ["-Wl,-force_load,%{libraries_to_link.name}"],
                            ),
                        ],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "static_library",
                        ),
                        flag_groups = [
                            flag_group(
                                expand_if_false = "libraries_to_link.is_whole_archive",
                                flags = ["%{libraries_to_link.name}"],
                            ),
                            flag_group(
                                expand_if_true = "libraries_to_link.is_whole_archive",
                                flags = ["-Wl,-force_load,%{libraries_to_link.name}"],
                            ),
                        ],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "dynamic_library",
                        ),
                        flags = ["-l%{libraries_to_link.name}"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "versioned_dynamic_library",
                        ),
                        flags = ["-l:%{libraries_to_link.name}"],
                    ),
                    flag_group(
                        expand_if_true = "libraries_to_link.is_whole_archive",
                        flag_groups = [
                            flag_group(
                                expand_if_false = "macos_flags",
                                flags = ["-Wl,-no-whole-archive"],
                            ),
                        ],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file_group",
                        ),
                        flags = ["-Wl,--end-lib"],
                    ),
                ],
                iterate_over = "libraries_to_link",
            ),
            # Note that the params file comes at the end, after the
            # libraries to link above.
            flag_group(
                expand_if_available = "linker_param_file",
                flags = ["@%{linker_param_file}"],
            ),
        ],
    )],
)

# Archive actions have an entirely independent set of flags and don't
# interact with either compiler or link actions.
default_archiver_flags_feature = feature(
    name = "default_archiver_flags",
    enabled = True,
    flag_sets = [flag_set(
        actions = [ACTION_NAMES.cpp_link_static_library],
        flag_groups = [
            flag_group(flags = ["rcsD"]),
            flag_group(
                expand_if_available = "output_execpath",
                flags = ["%{output_execpath}"],
            ),
            flag_group(
                expand_if_available = "libraries_to_link",
                flag_groups = [
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file",
                        ),
                        flags = ["%{libraries_to_link.name}"],
                    ),
                    flag_group(
                        expand_if_equal = variable_with_value(
                            name = "libraries_to_link.type",
                            value = "object_file_group",
                        ),
                        flags = ["%{libraries_to_link.object_files}"],
                        iterate_over = "libraries_to_link.object_files",
                    ),
                ],
                iterate_over = "libraries_to_link",
            ),
            flag_group(
                expand_if_available = "linker_param_file",
                flags = ["@%{linker_param_file}"],
            ),
        ],
    )],
)

# Note that the order of features is significant in this list and determines the
# relative order of flags from the features listed.
linking_features = [
    default_archiver_flags_feature,
]