How do I configure cmake to work with rsp files when using IAR compiler - cmake

Question

When using the IAR compiler I get an error when creating a library. This uses "iarchive.exe" in the IAR bin directory to create a library file.
The issue occurs when the number of object files exceeds the Windows10 command line limit (about 8000 bytes).
When the limit is exceeded CMake creates a ".rsp" file and the response file has a 3 bytes (Byte Order Mark) at the start of the file.
I am using a licensed version of the IAR compiler.
The tools are version 7.2.
set(CMAKE_SYSTEM_NAME Generic)
set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
set(CMAKE_SYSTEM_PROCESSOR arm)
set(IAR_INSTALL_DIR "C:/Program Files (x86)/IAR Systems/Embedded
Workbench 7.2")
architectures
set(TOOLKIT_DIR "${IAR_INSTALL_DIR}/${CMAKE_SYSTEM_PROCESSOR}")
if(UNIX)
set(ENV{PATH} "${TOOLKIT_DIR}/bin:$ENV{PATH}")
else()
set(ENV{PATH} "${TOOLKIT_DIR}/bin;$ENV{PATH}")
endif()
Compiler and Assembler
set(CMAKE_C_COMPILER "icc${CMAKE_SYSTEM_PROCESSOR}")
set(CMAKE_CXX_COMPILER "icc${CMAKE_SYSTEM_PROCESSOR}")
set(CMAKE_ASM_COMPILER "iasm${CMAKE_SYSTEM_PROCESSOR}")
SET(CMAKE_C_USE_RESPONSE_FILE_FOR_OBJECTS 0)
To configure cmake
cmake -H.. -B. -G "Ninja Multi-Config" -DCMAKE_TOOLCHAIN_FILE=..\iar-toolchain.cmake
I have also tried:
cmake -H.. -B. -G "NMake Makefiles" -DCMAKE_TOOLCHAIN_FILE=..\iar-toolchain.cmake
Below is the error message generated during the build.
C:\Firmware\SRFN\build>cmake --build . --target SrfnDcu
[1/20] Linking C static library Debug\libpsp_dcu_k64f120m.a
FAILED: Debug/libpsp_dcu_k64f120m.a
cmd.exe /C "cd . && C:\PROGRA~2\IARSYS~1\EMBEDD~1.2\arm\bin\iarchive.exe Debug\libpsp_dcu_k64f120m.a --create -f CMakeFiles\psp_dcu_k64f120m.Debug.rsp && cd ."
Fatal error[La001]: could not open file "C:\Firmware\SRFN\build\CMakeFiles\p
sp_dcu_k64f120m.dir\Debug\DCU\OS\mqx\source\psp\cortex_m\compiler\iar
\comp.c.o"
Fatal error detected, aborting.
One solution to the problem was to use a newer version of "iarchive.exe" that was in IAR Version 8.2.
Basically is seems that IAR updated "iarchive.exe" to support this.