# ################################################################
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under both the BSD-style license (found in the
# LICENSE file in the root directory of this source tree) and the GPLv2 (found
# in the COPYING file in the root directory of this source tree).
# ################################################################

# Merge the Cargo static library into CMake's libzstd static archive.  Keeping
# the object members in one archive matters: C objects call migrated Rust
# functions and Rust objects call C helpers, so two separate archives are
# sensitive to the consumer linker's archive scan order.

foreach(_zstd_required ARCHIVER RUST_ARCHIVE TARGET_ARCHIVE WORK_DIR)
    if(NOT DEFINED ${_zstd_required})
        message(FATAL_ERROR "${_zstd_required} is required")
    endif()
endforeach()

file(REMOVE_RECURSE "${WORK_DIR}")
file(MAKE_DIRECTORY "${WORK_DIR}")

if(ARCHIVER_STYLE STREQUAL "MSVC")
    # lib.exe accepts libraries as inputs and writes their object members to a
    # new archive.  Keep the original C archive separate while it is read,
    # because /OUT must not overwrite an input archive.
    set(_zstd_c_archive "${WORK_DIR}/libzstd-c.lib")
    execute_process(
        COMMAND "${CMAKE_COMMAND}" -E copy "${TARGET_ARCHIVE}" "${_zstd_c_archive}"
        RESULT_VARIABLE _zstd_copy_result)
    if(NOT _zstd_copy_result EQUAL 0)
        message(FATAL_ERROR "could not copy ${TARGET_ARCHIVE} for Rust archive merge")
    endif()

    execute_process(
        COMMAND "${ARCHIVER}" "/OUT:${TARGET_ARCHIVE}" "${_zstd_c_archive}" "${RUST_ARCHIVE}"
        RESULT_VARIABLE _zstd_merge_result
        OUTPUT_VARIABLE _zstd_merge_output
        ERROR_VARIABLE _zstd_merge_error)
else()
    execute_process(
        COMMAND "${ARCHIVER}" x "${RUST_ARCHIVE}"
        WORKING_DIRECTORY "${WORK_DIR}"
        RESULT_VARIABLE _zstd_extract_result
        OUTPUT_VARIABLE _zstd_extract_output
        ERROR_VARIABLE _zstd_extract_error)
    if(NOT _zstd_extract_result EQUAL 0)
        message(FATAL_ERROR
            "could not extract Rust archive ${RUST_ARCHIVE}: ${_zstd_extract_output}${_zstd_extract_error}")
    endif()

    file(GLOB _zstd_rust_objects "${WORK_DIR}/*.o" "${WORK_DIR}/*.obj")
    if(NOT _zstd_rust_objects)
        message(FATAL_ERROR "Rust archive ${RUST_ARCHIVE} did not contain object files")
    endif()

    execute_process(
        COMMAND "${ARCHIVER}" q "${TARGET_ARCHIVE}" ${_zstd_rust_objects}
        RESULT_VARIABLE _zstd_merge_result
        OUTPUT_VARIABLE _zstd_merge_output
        ERROR_VARIABLE _zstd_merge_error)
endif()

if(NOT _zstd_merge_result EQUAL 0)
    message(FATAL_ERROR
        "could not merge Rust archive ${RUST_ARCHIVE}: ${_zstd_merge_output}${_zstd_merge_error}")
endif()

if(DEFINED RANLIB AND NOT "${RANLIB}" STREQUAL "" AND NOT ARCHIVER_STYLE STREQUAL "MSVC")
    execute_process(
        COMMAND "${RANLIB}" "${TARGET_ARCHIVE}"
        RESULT_VARIABLE _zstd_ranlib_result
        OUTPUT_VARIABLE _zstd_ranlib_output
        ERROR_VARIABLE _zstd_ranlib_error)
    if(NOT _zstd_ranlib_result EQUAL 0)
        message(FATAL_ERROR
            "could not index ${TARGET_ARCHIVE}: ${_zstd_ranlib_output}${_zstd_ranlib_error}")
    endif()
endif()

file(REMOVE_RECURSE "${WORK_DIR}")