1include(CMakeCheckCompilerFlagCommonPatterns) 2 3# Test compiler can compile simple C/C++/Objective-C program without invoking 4# the linker. 5# 6# try_compile_only( 7# OUTPUT_VAR 8# [SOURCE source_text] 9# [FLAGS flag_0 [ flag_1 ]] 10# ) 11# 12# OUTPUT_VAR - The variable name to store the result. The result is a boolean 13# `True` or `False`. 14# 15# SOURCE - Optional. If specified use source the source text string 16# specified. If not specified source code will be used that is C, 17# C++, and Objective-C compatible. 18# 19# FLAGS - Optional. If specified pass the one or more specified flags to 20# the compiler. 21# 22# EXAMPLES: 23# 24# try_compile_only(HAS_F_NO_RTTI FLAGS "-fno-rtti") 25# 26# try_compile_only(HAS_CXX_AUTO_TYPE_DECL 27# SOURCE "int foo(int x) { auto y = x + 1; return y;}" 28# FLAGS "-x" "c++" "-std=c++11" "-Werror=c++11-extensions" 29# ) 30# 31function(try_compile_only output) 32 # NOTE: `SOURCE` needs to be a multi-argument because source code 33 # often contains semicolons which happens to be CMake's list separator 34 # which confuses `cmake_parse_arguments()`. 35 cmake_parse_arguments(ARG "" "" "SOURCE;FLAGS" ${ARGN}) 36 if (ARG_UNPARSED_ARGUMENTS) 37 message(FATAL_ERROR "Unexpected arguments \"${ARG_UNPARSED_ARGUMENTS}\"") 38 endif() 39 if(NOT ARG_SOURCE) 40 set(ARG_SOURCE "int foo(int x, int y) { return x + y; }\n") 41 endif() 42 set(SIMPLE_C ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/src.c) 43 file(WRITE ${SIMPLE_C} "${ARG_SOURCE}\n") 44 string(REGEX MATCHALL "<[A-Za-z0-9_]*>" substitutions 45 ${CMAKE_C_COMPILE_OBJECT}) 46 47 set(TRY_COMPILE_FLAGS "${ARG_FLAGS}") 48 if(CMAKE_C_COMPILER_ID MATCHES Clang AND CMAKE_C_COMPILER_TARGET) 49 list(APPEND TRY_COMPILE_FLAGS "-target ${CMAKE_C_COMPILER_TARGET}") 50 endif() 51 52 string(REPLACE ";" " " extra_flags "${TRY_COMPILE_FLAGS}") 53 54 set(test_compile_command "${CMAKE_C_COMPILE_OBJECT}") 55 foreach(substitution ${substitutions}) 56 if(substitution STREQUAL "<CMAKE_C_COMPILER>") 57 string(REPLACE "<CMAKE_C_COMPILER>" 58 "${CMAKE_C_COMPILER}" test_compile_command ${test_compile_command}) 59 elseif(substitution STREQUAL "<OBJECT>") 60 string(REPLACE "<OBJECT>" 61 "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/test.o" 62 test_compile_command ${test_compile_command}) 63 elseif(substitution STREQUAL "<SOURCE>") 64 string(REPLACE "<SOURCE>" "${SIMPLE_C}" test_compile_command 65 ${test_compile_command}) 66 elseif(substitution STREQUAL "<FLAGS>") 67 string(REPLACE "<FLAGS>" "${CMAKE_C_FLAGS} ${extra_flags}" 68 test_compile_command ${test_compile_command}) 69 else() 70 string(REPLACE "${substitution}" "" test_compile_command 71 ${test_compile_command}) 72 endif() 73 endforeach() 74 75 # Strip quotes from the compile command, as the compiler is not expecting 76 # quoted arguments (see discussion on D62063 for when this can come up). If 77 # the quotes were there for arugments with spaces in them, the quotes were 78 # not going to help since the string gets split on spaces below. 79 string(REPLACE "\"" "" test_compile_command "${test_compile_command}") 80 81 string(REPLACE " " ";" test_compile_command "${test_compile_command}") 82 83 execute_process( 84 COMMAND ${test_compile_command} 85 RESULT_VARIABLE result 86 OUTPUT_VARIABLE TEST_OUTPUT 87 ERROR_VARIABLE TEST_ERROR 88 ) 89 90 CHECK_COMPILER_FLAG_COMMON_PATTERNS(_CheckCCompilerFlag_COMMON_PATTERNS) 91 set(ERRORS_FOUND OFF) 92 foreach(var ${_CheckCCompilerFlag_COMMON_PATTERNS}) 93 if("${var}" STREQUAL "FAIL_REGEX") 94 continue() 95 endif() 96 if("${TEST_ERROR}" MATCHES "${var}" OR "${TEST_OUTPUT}" MATCHES "${var}") 97 set(ERRORS_FOUND ON) 98 endif() 99 endforeach() 100 101 if(result EQUAL 0 AND NOT ERRORS_FOUND) 102 set(${output} True PARENT_SCOPE) 103 else() 104 file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log 105 "Testing compiler for supporting " ${ARGN} ":\n" 106 "Command: ${test_compile_command}\n" 107 "${TEST_OUTPUT}\n${TEST_ERROR}\n${result}\n") 108 set(${output} False PARENT_SCOPE) 109 endif() 110endfunction() 111 112function(builtin_check_c_compiler_flag flag output) 113 if(NOT DEFINED ${output}) 114 message(STATUS "Performing Test ${output}") 115 try_compile_only(result FLAGS ${flag}) 116 set(${output} ${result} CACHE INTERNAL "Compiler supports ${flag}") 117 if(${result}) 118 message(STATUS "Performing Test ${output} - Success") 119 else() 120 message(STATUS "Performing Test ${output} - Failed") 121 endif() 122 endif() 123endfunction() 124 125function(builtin_check_c_compiler_source output source) 126 if(NOT DEFINED ${output}) 127 message(STATUS "Performing Test ${output}") 128 try_compile_only(result SOURCE ${source}) 129 set(${output} ${result} CACHE INTERNAL "Compiler supports ${flag}") 130 if(${result}) 131 message(STATUS "Performing Test ${output} - Success") 132 else() 133 message(STATUS "Performing Test ${output} - Failed") 134 endif() 135 endif() 136endfunction() 137