1function(check_section_exists section output)
2  cmake_parse_arguments(ARG "" "" "SOURCE;FLAGS" ${ARGN})
3  if(NOT ARG_SOURCE)
4    set(ARG_SOURCE "int main(void) { return 0; }\n")
5  endif()
6
7  string(RANDOM TARGET_NAME)
8  set(TARGET_NAME "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/cmTC_${TARGET_NAME}.dir")
9  file(MAKE_DIRECTORY ${TARGET_NAME})
10
11  file(WRITE "${TARGET_NAME}/CheckSectionExists.c" "${ARG_SOURCE}\n")
12
13  string(REGEX MATCHALL "<[A-Za-z0-9_]*>" substitutions
14         ${CMAKE_C_COMPILE_OBJECT})
15
16  set(try_compile_flags "${ARG_FLAGS}")
17  if(CMAKE_C_COMPILER_ID MATCHES Clang AND CMAKE_C_COMPILER_TARGET)
18    list(APPEND try_compile_flags "-target ${CMAKE_C_COMPILER_TARGET}")
19  endif()
20  append_list_if(COMPILER_RT_HAS_FNO_LTO_FLAG -fno-lto try_compile_flags)
21  if(NOT COMPILER_RT_ENABLE_PGO)
22    if(LLVM_PROFDATA_FILE AND COMPILER_RT_HAS_FNO_PROFILE_INSTR_USE_FLAG)
23      list(APPEND try_compile_flags "-fno-profile-instr-use")
24    endif()
25    if(LLVM_BUILD_INSTRUMENTED MATCHES IR AND COMPILER_RT_HAS_FNO_PROFILE_GENERATE_FLAG)
26      list(APPEND try_compile_flags "-fno-profile-generate")
27    elseif((LLVM_BUILD_INSTRUMENTED OR LLVM_BUILD_INSTRUMENTED_COVERAGE) AND COMPILER_RT_HAS_FNO_PROFILE_INSTR_GENERATE_FLAG)
28      list(APPEND try_compile_flags "-fno-profile-instr-generate")
29      if(LLVM_BUILD_INSTRUMENTED_COVERAGE AND COMPILER_RT_HAS_FNO_COVERAGE_MAPPING_FLAG)
30        list(APPEND try_compile_flags "-fno-coverage-mapping")
31      endif()
32    endif()
33  endif()
34
35  string(REPLACE ";" " " extra_flags "${try_compile_flags}")
36
37  set(test_compile_command "${CMAKE_C_COMPILE_OBJECT}")
38  foreach(substitution ${substitutions})
39    if(substitution STREQUAL "<CMAKE_C_COMPILER>")
40      string(REPLACE "<CMAKE_C_COMPILER>" "${CMAKE_C_COMPILER} ${CMAKE_C_COMPILER_ARG1}"
41             test_compile_command ${test_compile_command})
42    elseif(substitution STREQUAL "<OBJECT>")
43      string(REPLACE "<OBJECT>" "${TARGET_NAME}/CheckSectionExists.o"
44             test_compile_command ${test_compile_command})
45    elseif(substitution STREQUAL "<SOURCE>")
46      string(REPLACE "<SOURCE>" "${TARGET_NAME}/CheckSectionExists.c"
47             test_compile_command ${test_compile_command})
48    elseif(substitution STREQUAL "<FLAGS>")
49      string(REPLACE "<FLAGS>" "${CMAKE_C_FLAGS} ${extra_flags}"
50             test_compile_command ${test_compile_command})
51    else()
52      string(REPLACE "${substitution}" "" test_compile_command
53             ${test_compile_command})
54    endif()
55  endforeach()
56
57  # Strip quotes from the compile command, as the compiler is not expecting
58  # quoted arguments (potential quotes added from D62063).
59  string(REPLACE "\"" "" test_compile_command "${test_compile_command}")
60
61  string(REPLACE " " ";" test_compile_command "${test_compile_command}")
62
63  execute_process(
64    COMMAND ${test_compile_command}
65    RESULT_VARIABLE TEST_RESULT
66    OUTPUT_VARIABLE TEST_OUTPUT
67    ERROR_VARIABLE TEST_ERROR
68  )
69
70  # Explicitly throw a fatal error message if test_compile_command fails.
71  if(TEST_RESULT)
72    message(FATAL_ERROR "${TEST_ERROR}")
73    return()
74  endif()
75
76  execute_process(
77    COMMAND ${CMAKE_OBJDUMP} -h "${TARGET_NAME}/CheckSectionExists.o"
78    RESULT_VARIABLE CHECK_RESULT
79    OUTPUT_VARIABLE CHECK_OUTPUT
80    ERROR_VARIABLE CHECK_ERROR
81  )
82  string(FIND "${CHECK_OUTPUT}" "${section}" SECTION_FOUND)
83
84  if(NOT SECTION_FOUND EQUAL -1)
85    set(${output} TRUE PARENT_SCOPE)
86  else()
87    set(${output} FALSE PARENT_SCOPE)
88  endif()
89
90  file(REMOVE_RECURSE ${TARGET_NAME})
91endfunction()
92