cmake/preload/toolchains/pico_arm_clang.cmake

# NOTE: THIS IS A WIP ONLY PICO_ARM_GCC IS CURRENTLY SUPPORTED, however should work with LLVM Embedded Toolchain for ARM
# version 14.0.0 https://github.com/ARM-software/LLVM-embedded-toolchain-for-Arm/releases/tag/release-14.0.0
# todo there is probably a more "cmake" way of doing this going thru the standard path with our "PICO" platform
#  i.e. CMake<Lang>Information and whatnot
include(${CMAKE_CURRENT_LIST_DIR}/find_compiler.cmake)

# include our Platform/pico.cmake
set(CMAKE_SYSTEM_NAME PICO)
set(CMAKE_SYSTEM_PROCESSOR cortex-m0plus)

# Find CLANG
pico_find_compiler(PICO_COMPILER_CC clang)
pico_find_compiler(PICO_COMPILER_CXX clang)
#pico_find_compiler(PICO_COMPILER_ASM armasm)
set(PICO_COMPILER_ASM "${PICO_COMPILER_CC}" CACHE INTERNAL "")
pico_find_compiler(PICO_OBJCOPY llvm-objcopy)
pico_find_compiler(PICO_OBJDUMP llvm-objdump)

# Specify the cross compiler.
set(CMAKE_C_COMPILER ${PICO_COMPILER_CC} CACHE FILEPATH "C compiler")
set(CMAKE_CXX_COMPILER ${PICO_COMPILER_CXX} CACHE FILEPATH "C++ compiler")
set(CMAKE_C_OUTPUT_EXTENSION .o)

# todo should we be including CMakeASMInformation anyway - i guess that is host side
set(CMAKE_ASM_COMPILER ${PICO_COMPILER_ASM} CACHE FILEPATH "ASM compiler")
set(CMAKE_ASM_COMPILE_OBJECT "<CMAKE_ASM_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT>   -c <SOURCE>")
set(CMAKE_INCLUDE_FLAG_ASM "-I")
set(CMAKE_OBJCOPY ${PICO_OBJCOPY} CACHE FILEPATH "")
set(CMAKE_OBJDUMP ${PICO_OBJDUMP} CACHE FILEPATH "")

# Add target system root to cmake find path.
get_filename_component(PICO_COMPILER_DIR "${PICO_COMPILER_CC}" DIRECTORY)
get_filename_component(CMAKE_FIND_ROOT_PATH "${PICO_COMPILER_DIR}" DIRECTORY)

# Look for includes and libraries only in the target system prefix.
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)

option(PICO_DEOPTIMIZED_DEBUG "Build debug builds with -O0" 0)

# Oz is preferred for Clang (verses CMake default -Os) see also https://gitlab.kitware.com/cmake/cmake/-/issues/22458
set(CMAKE_C_FLAGS_MINSIZEREL "-Oz -DNDEBUG")

set(ARM_TOOLCHAIN_COMMON_FLAGS "--target=armv6m-none-eabi -mfloat-abi=soft -march=armv6m --sysroot ${PICO_COMPILER_DIR}/../lib/clang-runtimes/armv6m_soft_nofp")
include(${CMAKE_CURRENT_LIST_DIR}/set_flags.cmake)