# ===----------------------------------------------------------------------===##
#
# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#
# ===----------------------------------------------------------------------===##

# This configuration builds the C++23 std module.
# It is build when the current lit configuration supports modules.
#
# TODO MODULES Evaluate whether this file can be removed when CMake supports
# modules in libc++.

import os
import site
import subprocess
import libcxx.test.params, libcxx.test.config, libcxx.test.dsl


def getSubstitution(substitution, config):
    for orig, replacement in config.substitutions:
        if orig == substitution:
            return replacement
    raise ValueError("Substitution {} is not in the config.".format(substitution))


def appendToSubstitution(substitutions, key, value):
    return [(k, v + " " + value) if k == key else (k, v) for (k, v) in substitutions]


std = getSubstitution("%{cxx_std}", config)
if std == "cxx26":
    std = "26"
elif std == "cxx23":
    std = "23"
elif std == "cxx20":
    std = "20"
else:
    std = ""

if (
    std
    and not "libcpp-has-no-std-modules" in config.available_features
    and not "clang-modules-build" in config.available_features
):
    build = os.path.join(config.test_exec_root, "__config_module__")
    config.substitutions = appendToSubstitution(
        config.substitutions,
        "%{compile_flags}",
        "-fprebuilt-module-path="
        + os.path.join(config.test_exec_root, "__config_module__/CMakeFiles/std.dir"),
    )

    cmake = getSubstitution("%{cmake}", config)
    flags = getSubstitution("%{flags}", config)
    if "c++experimental" in config.available_features:
        flags = f"{flags} -D_LIBCPP_ENABLE_EXPERIMENTAL"

    subprocess.check_call(
        [cmake, f"-DCMAKE_CXX_STANDARD={std}", f"-DCMAKE_CXX_FLAGS={flags}", build],
        env={},
    )
    subprocess.check_call([cmake, "--build", build, "--", "-v"], env={})
    config.substitutions = appendToSubstitution(
        config.substitutions,
        "%{link_flags}",
        os.path.join(build, "libc++std.a"),
    )

    config.substitutions = appendToSubstitution(
        config.substitutions,
        "%{compile_flags}",
        "-fprebuilt-module-path="
        + os.path.join(
            config.test_exec_root, "__config_module__/CMakeFiles/std.compat.dir"
        ),
    )
    config.substitutions = appendToSubstitution(
        config.substitutions,
        "%{link_flags}",
        os.path.join(build, "libc++std.compat.a"),
    )