# Copyright 2019 The Meson development team
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Mixins for compilers that *are* linkers.

While many compilers (such as gcc and clang) are used by meson to dispatch
linker commands and other (like MSVC) are not, a few (such as DMD) actually
are both the linker and compiler in one binary. This module provides mixin
classes for those cases.
"""

import os
import typing as T

from ... import mesonlib

if T.TYPE_CHECKING:
    from ...coredata import OptionDictType
    from ...environment import Environment


class LinkerEnvVarsMixin:

    """Mixin reading LDFLAGS from the environment."""

    def get_linker_args_from_envvars(self) -> T.List[str]:
        flags = os.environ.get('LDFLAGS')
        if not flags:
            return []
        return mesonlib.split_args(flags)


class BasicLinkerIsCompilerMixin:

    """Provides a baseline of methods that a linker would implement.

    In every case this provides a "no" or "empty" answer. If a compiler
    implements any of these it needs a different mixin or to override that
    functionality itself.
    """

    def sanitizer_link_args(self, value: str) -> T.List[str]:
        return []

    def get_lto_link_args(self) -> T.List[str]:
        return []

    def can_linker_accept_rsp(self) -> bool:
        return mesonlib.is_windows()

    def get_linker_exelist(self) -> T.List[str]:
        return self.exelist.copy()

    def get_linker_output_args(self, output: str) -> T.List[str]:
        return []

    def get_linker_always_args(self) -> T.List[str]:
        return []

    def get_linker_lib_prefix(self) -> str:
        return ''

    def get_option_link_args(self, options: 'OptionDictType') -> T.List[str]:
        return []

    def has_multi_link_args(self, args: T.List[str], env: 'Environment') -> T.Tuple[bool, bool]:
        return False, False

    def get_link_debugfile_args(self, targetfile: str) -> T.List[str]:
        return []

    def get_std_shared_lib_link_args(self) -> T.List[str]:
        return []

    def get_std_shared_module_args(self, options: 'OptionDictType') -> T.List[str]:
        return self.get_std_shared_lib_link_args()

    def get_link_whole_for(self, args: T.List[str]) -> T.List[str]:
        raise mesonlib.EnvironmentException(
            'Linker {} does not support link_whole'.format(self.id))

    def get_allow_undefined_link_args(self) -> T.List[str]:
        raise mesonlib.EnvironmentException(
            'Linker {} does not support allow undefined'.format(self.id))

    def get_pie_link_args(self) -> T.List[str]:
        m = 'Linker {} does not support position-independent executable'
        raise mesonlib.EnvironmentException(m.format(self.id))

    def get_undefined_link_args(self) -> T.List[str]:
        return []

    def get_coverage_link_args(self) -> T.List[str]:
        m = "Linker {} doesn't implement coverage data generation.".format(self.id)
        raise mesonlib.EnvironmentException(m)

    def no_undefined_link_args(self) -> T.List[str]:
        return []

    def bitcode_args(self) -> T.List[str]:
        raise mesonlib.MesonException("This linker doesn't support bitcode bundles")

    def get_soname_args(self, for_machine: 'mesonlib.MachineChoice',
                        prefix: str, shlib_name: str, suffix: str, soversion: str,
                        darwin_versions: T.Tuple[str, str],
                        is_shared_module: bool) -> T.List[str]:
        raise mesonlib.MesonException("This linker doesn't support soname args")

    def build_rpath_args(self, env: 'Environment', build_dir: str, from_dir: str,
                         rpath_paths: str, build_rpath: str,
                         install_rpath: str) -> T.List[str]:
        return []

    def get_linker_debug_crt_args(self) -> T.List[str]:
        return []

    def get_asneeded_args(self) -> T.List[str]:
        return []

    def get_buildtype_linker_args(self, buildtype: str) -> T.List[str]:
        return []
