1# SPDX-License-Identifier: Apache-2.0
2
3# Configuration for host installed clang
4#
5
6set(NOSTDINC "")
7
8# Note that NOSYSDEF_CFLAG may be an empty string, and
9# set_ifndef() does not work with empty string.
10if(NOT DEFINED NOSYSDEF_CFLAG)
11  set(NOSYSDEF_CFLAG -undef)
12endif()
13
14if(DEFINED TOOLCHAIN_HOME)
15  set(find_program_clang_args PATHS ${TOOLCHAIN_HOME} NO_DEFAULT_PATH)
16endif()
17
18find_program(CMAKE_C_COMPILER   clang   ${find_program_clang_args})
19find_program(CMAKE_CXX_COMPILER clang++ ${find_program_clang_args})
20
21if(SYSROOT_DIR)
22  # The toolchain has specified a sysroot dir, pass it to the compiler
23  list(APPEND TOOLCHAIN_C_FLAGS "--sysroot=${SYSROOT_DIR}")
24  list(APPEND TOOLCHAIN_LD_FLAGS "--sysroot=${SYSROOT_DIR}")
25endif()
26
27if(NOT "${ARCH}" STREQUAL "posix")
28  include(${ZEPHYR_BASE}/cmake/gcc-m-cpu.cmake)
29  include(${ZEPHYR_BASE}/cmake/gcc-m-fpu.cmake)
30
31  if("${ARCH}" STREQUAL "arm")
32    include(${ZEPHYR_BASE}/cmake/compiler/clang/target_arm.cmake)
33  elseif("${ARCH}" STREQUAL "arm64")
34    include(${ZEPHYR_BASE}/cmake/compiler/clang/target_arm64.cmake)
35  elseif("${ARCH}" STREQUAL "riscv")
36    include(${ZEPHYR_BASE}/cmake/compiler/gcc/target_riscv.cmake)
37  endif()
38
39  if(DEFINED CMAKE_C_COMPILER_TARGET)
40    set(clang_target_flag "--target=${CMAKE_C_COMPILER_TARGET}")
41  endif()
42
43  foreach(file_name include/stddef.h)
44    execute_process(
45      COMMAND ${CMAKE_C_COMPILER} --print-file-name=${file_name}
46      OUTPUT_VARIABLE _OUTPUT
47      )
48    get_filename_component(_OUTPUT "${_OUTPUT}" DIRECTORY)
49    string(REGEX REPLACE "\n" "" _OUTPUT ${_OUTPUT})
50
51    list(APPEND NOSTDINC ${_OUTPUT})
52  endforeach()
53
54  foreach(isystem_include_dir ${NOSTDINC})
55    list(APPEND isystem_include_flags -isystem "\"${isystem_include_dir}\"")
56  endforeach()
57
58  if(CONFIG_X86)
59    if(CONFIG_64BIT)
60      list(APPEND TOOLCHAIN_C_FLAGS "-m64")
61    else()
62      list(APPEND TOOLCHAIN_C_FLAGS "-m32")
63    endif()
64  endif()
65
66  # LLVM will use a default sysroot for selection of the C library. The default
67  # C library sysroot was defined at built time of clang/LLVM.
68  #
69  # For example, LLVM for Arm comes pre-built with Picolibc, and thus no flags
70  # are required for selecting Picolibc.
71  #
72  # Other clang/LLVM distributions may come with other pre-built C libraries.
73  # clang/LLVM supports using an alternative C library, either by direct linking,
74  # or by specifying '--sysroot <path>'. Sysroot can also be passed using the
75  # CMake variable SYSROOT_DIR which will append the '--sysroot <path>' flags.
76  #
77  # LLVM for Arm provides a 'newlib.cfg' file for newlib C selection.
78  # Let us support this principle by looking for a dedicated 'newlib.cfg' or
79  # 'picolibc.cfg' and specify '--config <spec>.cfg' if such a file is found.
80  # If no cfg-file matching the chosen C implementation, then we assume that the
81  # chosen C implementation is identical to the default C library used be the
82  # toolchain.
83  if(CONFIG_NEWLIB_LIBC)
84    file(GLOB_RECURSE newlib_cfg ${LLVM_TOOLCHAIN_PATH}/newlib.cfg)
85    if(newlib_cfg)
86      list(GET newlib_cfg 0 newlib_cfg)
87      set_linker_property(PROPERTY c_library "--config=${newlib_cfg};-lc")
88      list(APPEND CMAKE_REQUIRED_FLAGS --config=${newlib_cfg})
89      list(APPEND TOOLCHAIN_C_FLAGS --config=${newlib_cfg})
90    endif()
91  endif()
92
93  if(CONFIG_PICOLIBC)
94    file(GLOB_RECURSE picolibc_cfg ${LLVM_TOOLCHAIN_PATH}/picolibc.cfg)
95    if(picolibc_cfg)
96      list(GET picolibc_cfg 0 picolibc_cfg)
97      set_linker_property(PROPERTY c_library "--config=${picolibc_cfg};-lc")
98      list(APPEND CMAKE_REQUIRED_FLAGS --config=${picolibc_cfg})
99      list(APPEND TOOLCHAIN_C_FLAGS --config=${picolibc_cfg})
100    endif()
101  endif()
102
103  list(APPEND CMAKE_REQUIRED_FLAGS -nostartfiles -nostdlib ${isystem_include_flags})
104  string(REPLACE ";" " " CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
105
106endif()
107