mbed-os/tools/cmake/mbed_set_linker_script.cmake

51 lines
2.2 KiB
CMake

# Copyright (c) 2021 ARM Limited. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Preprocesses and sets the linker script for an Mbed target.
#
function(mbed_set_linker_script input_target raw_linker_script_path)
set(LINKER_SCRIPT_PATH ${CMAKE_CURRENT_BINARY_DIR}/${input_target}.link_script.ld)
# To avoid path limits on Windows, we create a "response file" and set the path to it as a
# global property. We need this solely to pass the compile definitions to GCC's preprocessor,
# so it can expand any macro definitions in the linker script.
get_property(_linker_preprocess_definitions GLOBAL PROPERTY COMPILE_DEFS_RESPONSE_FILE)
if(MBED_TOOLCHAIN STREQUAL "GCC_ARM")
add_custom_command(
OUTPUT
${LINKER_SCRIPT_PATH}
PRE_LINK
COMMAND
${CMAKE_C_COMPILER} ${_linker_preprocess_definitions}
-E -x assembler-with-cpp
-P ${raw_linker_script_path}
-o ${LINKER_SCRIPT_PATH}
WORKING_DIRECTORY
${CMAKE_CURRENT_SOURCE_DIR}
COMMENT
"Link line:"
VERBATIM
)
# CMake will not let us add PRE_LINK commands to INTERFACE targets, and input_target could
# be an INTERFACE target.
# To get around this we create an intermediate custom target depending on the preprocessed
# linker script output by CPP. We add this custom target as a dependency of input_target.
# This ensures CMake runs our custom command to preprocess the linker script before trying
# to build input_target.
set(LinkerScriptTarget ${input_target}LinkerScript)
add_custom_target(${LinkerScriptTarget} DEPENDS ${LINKER_SCRIPT_PATH} VERBATIM)
add_dependencies(${input_target} ${LinkerScriptTarget})
target_link_options(${input_target}
INTERFACE
"-T" "${LINKER_SCRIPT_PATH}"
)
elseif(MBED_TOOLCHAIN STREQUAL "ARM")
target_link_options(${input_target}
INTERFACE
"--scatter=${raw_linker_script_path}"
"--predefine=${_linker_preprocess_definitions}"
"--map"
)
endif()
endfunction()