cmake/linker/lld/target.cmake

# SPDX-License-Identifier: Apache-2.0
set_property(TARGET linker PROPERTY devices_start_symbol "_device_list_start")

find_package(LlvmLld 14.0.0 REQUIRED)
set(CMAKE_LINKER ${LLVMLLD_LINKER})

set_ifndef(LINKERFLAGPREFIX -Wl)

list(APPEND TOOLCHAIN_LD_FLAGS -fuse-ld=lld)
list(APPEND CMAKE_REQUIRED_FLAGS -fuse-ld=lld)
string(REPLACE ";" " " CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")

# Run $LINKER_SCRIPT file through the C preprocessor, producing ${linker_script_gen}
# NOTE: ${linker_script_gen} will be produced at build-time; not at configure-time
macro(configure_linker_script linker_script_gen linker_pass_define)
  set(extra_dependencies ${ARGN})
  set(template_script_defines ${linker_pass_define})
  list(TRANSFORM template_script_defines PREPEND "-D")

  # Different generators deal with depfiles differently.
  if(CMAKE_GENERATOR STREQUAL "Unix Makefiles")
    # Note that the IMPLICIT_DEPENDS option is currently supported only
    # for Makefile generators and will be ignored by other generators.
    set(linker_script_dep IMPLICIT_DEPENDS C ${LINKER_SCRIPT})
  elseif(CMAKE_GENERATOR STREQUAL "Ninja")
    # Using DEPFILE with other generators than Ninja is an error.
    set(linker_script_dep DEPFILE ${PROJECT_BINARY_DIR}/${linker_script_gen}.dep)
  else()
    # TODO: How would the linker script dependencies work for non-linker
    # script generators.
    message(WARNING "This generator is not well supported. The
                    Linker script may not be regenerated when it should.")
    set(linker_script_dep "")
  endif()

  zephyr_get_include_directories_for_lang(C current_includes)

  add_custom_command(
    OUTPUT ${linker_script_gen}
    DEPENDS
    ${LINKER_SCRIPT}
    ${extra_dependencies}
    # NB: 'linker_script_dep' will use a keyword that ends 'DEPENDS'
    ${linker_script_dep}
    COMMAND ${CMAKE_C_COMPILER}
    -x assembler-with-cpp
    ${NOSYSDEF_CFLAG}
    -MD -MF ${linker_script_gen}.dep -MT ${linker_script_gen}
    -D_LINKER
    -D_ASMLANGUAGE
    -D__LLD_LINKER_CMD__
    -imacros ${AUTOCONF_H}
    ${current_includes}
    ${template_script_defines}
    -E ${LINKER_SCRIPT}
    -P # Prevent generation of debug `#line' directives.
    -o ${linker_script_gen}
    VERBATIM
    WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
    COMMAND_EXPAND_LISTS
  )
endmacro()

# Force symbols to be entered in the output file as undefined symbols
function(toolchain_ld_force_undefined_symbols)
  foreach(symbol ${ARGN})
    zephyr_link_libraries(${LINKERFLAGPREFIX},-u,${symbol})
  endforeach()
endfunction()

# Link a target to given libraries with toolchain-specific argument order
#
# Usage:
#   toolchain_ld_link_elf(
#     TARGET_ELF             <target_elf>
#     OUTPUT_MAP             <output_map_file_of_target>
#     LIBRARIES_PRE_SCRIPT   [libraries_pre_script]
#     LINKER_SCRIPT          <linker_script>
#     LIBRARIES_POST_SCRIPT  [libraries_post_script]
#     DEPENDENCIES           [dependencies]
#   )
function(toolchain_ld_link_elf)
  cmake_parse_arguments(
    TOOLCHAIN_LD_LINK_ELF                                     # prefix of output variables
    ""                                                        # list of names of the boolean arguments
    "TARGET_ELF;OUTPUT_MAP;LINKER_SCRIPT"                     # list of names of scalar arguments
    "LIBRARIES_PRE_SCRIPT;LIBRARIES_POST_SCRIPT;DEPENDENCIES" # list of names of list arguments
    ${ARGN}                                                   # input args to parse
  )

  target_link_libraries(
    ${TOOLCHAIN_LD_LINK_ELF_TARGET_ELF}
    ${TOOLCHAIN_LD_LINK_ELF_LIBRARIES_PRE_SCRIPT}
    ${TOPT}
    ${TOOLCHAIN_LD_LINK_ELF_LINKER_SCRIPT}
    ${TOOLCHAIN_LD_LINK_ELF_LIBRARIES_POST_SCRIPT}

    ${LINKERFLAGPREFIX},-Map=${TOOLCHAIN_LD_LINK_ELF_OUTPUT_MAP}
    ${LINKERFLAGPREFIX},--whole-archive
    ${WHOLE_ARCHIVE_LIBS}
    ${LINKERFLAGPREFIX},--no-whole-archive
    ${NO_WHOLE_ARCHIVE_LIBS}
    $<TARGET_OBJECTS:${OFFSETS_LIB}>
    -L${PROJECT_BINARY_DIR}

    ${TOOLCHAIN_LD_LINK_ELF_DEPENDENCIES}
  )
endfunction(toolchain_ld_link_elf)

# Function for finalizing link setup after Zephyr configuration has completed.
#
# This function will generate the correct CMAKE_C_LINK_EXECUTABLE / CMAKE_CXX_LINK_EXECUTABLE
# signature to ensure that standard c and runtime libraries are correctly placed
# and the end of link invocation and doesn't appear in the middle of the link
# command invocation.
macro(toolchain_linker_finalize)
  get_property(zephyr_std_libs TARGET linker PROPERTY lib_include_dir)
  get_property(link_order TARGET linker PROPERTY link_order_library)
  foreach(lib ${link_order})
    get_property(link_flag TARGET linker PROPERTY ${lib}_library)
    list(APPEND zephyr_std_libs "${link_flag}")
  endforeach()
  string(REPLACE ";" " " zephyr_std_libs "${zephyr_std_libs}")

 set(common_link "<LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES> ${zephyr_std_libs}")
 set(CMAKE_ASM_LINK_EXECUTABLE "<CMAKE_ASM_COMPILER> <FLAGS> <CMAKE_ASM_LINK_FLAGS> ${common_link}")
 set(CMAKE_C_LINK_EXECUTABLE   "<CMAKE_C_COMPILER> <FLAGS> <CMAKE_C_LINK_FLAGS> ${common_link}")
 set(CMAKE_CXX_LINK_EXECUTABLE "<CMAKE_CXX_COMPILER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> ${common_link}")
endmacro()

# Load toolchain_ld-family macros
include(${ZEPHYR_BASE}/cmake/linker/ld/target_relocation.cmake)
include(${ZEPHYR_BASE}/cmake/linker/ld/target_configure.cmake)