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| include(CMakeCheckCompilerFlagCommonPatterns)
# Test compiler can compile simple C/C++/Objective-C program without invoking
# the linker.
#
# try_compile_only(
# OUTPUT_VAR
# [SOURCE source_text]
# [FLAGS flag_0 [ flag_1 ]]
# )
#
# OUTPUT_VAR - The variable name to store the result. The result is a boolean
# `True` or `False`.
#
# SOURCE - Optional. If specified use source the source text string
# specified. If not specified source code will be used that is C,
# C++, and Objective-C compatible.
#
# FLAGS - Optional. If specified pass the one or more specified flags to
# the compiler.
#
# EXAMPLES:
#
# try_compile_only(HAS_F_NO_RTTI FLAGS "-fno-rtti")
#
# try_compile_only(HAS_CXX_AUTO_TYPE_DECL
# SOURCE "int foo(int x) { auto y = x + 1; return y;}"
# FLAGS "-x" "c++" "-std=c++11" "-Werror=c++11-extensions"
# )
#
function(try_compile_only output)
# NOTE: `SOURCE` needs to be a multi-argument because source code
# often contains semicolons which happens to be CMake's list separator
# which confuses `cmake_parse_arguments()`.
cmake_parse_arguments(ARG "" "" "SOURCE;FLAGS" ${ARGN})
if (ARG_UNPARSED_ARGUMENTS)
message(FATAL_ERROR "Unexpected arguments \"${ARG_UNPARSED_ARGUMENTS}\"")
endif()
if(NOT ARG_SOURCE)
set(ARG_SOURCE "int foo(int x, int y) { return x + y; }\n")
endif()
set(SIMPLE_C ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/src.c)
file(WRITE ${SIMPLE_C} "${ARG_SOURCE}\n")
string(REGEX MATCHALL "<[A-Za-z0-9_]*>" substitutions
${CMAKE_C_COMPILE_OBJECT})
set(TRY_COMPILE_FLAGS "${ARG_FLAGS}")
if(CMAKE_C_COMPILER_ID MATCHES Clang AND CMAKE_C_COMPILER_TARGET)
list(APPEND TRY_COMPILE_FLAGS "-target ${CMAKE_C_COMPILER_TARGET}")
endif()
string(REPLACE ";" " " extra_flags "${TRY_COMPILE_FLAGS}")
set(test_compile_command "${CMAKE_C_COMPILE_OBJECT}")
foreach(substitution ${substitutions})
if(substitution STREQUAL "<CMAKE_C_COMPILER>")
string(REPLACE "<CMAKE_C_COMPILER>"
"${CMAKE_C_COMPILER}" test_compile_command ${test_compile_command})
elseif(substitution STREQUAL "<OBJECT>")
string(REPLACE "<OBJECT>"
"${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/test.o"
test_compile_command ${test_compile_command})
elseif(substitution STREQUAL "<SOURCE>")
string(REPLACE "<SOURCE>" "${SIMPLE_C}" test_compile_command
${test_compile_command})
elseif(substitution STREQUAL "<FLAGS>")
string(REPLACE "<FLAGS>" "${CMAKE_C_FLAGS} ${extra_flags}"
test_compile_command ${test_compile_command})
else()
string(REPLACE "${substitution}" "" test_compile_command
${test_compile_command})
endif()
endforeach()
# Strip quotes from the compile command, as the compiler is not expecting
# quoted arguments (see discussion on D62063 for when this can come up). If
# the quotes were there for arugments with spaces in them, the quotes were
# not going to help since the string gets split on spaces below.
string(REPLACE "\"" "" test_compile_command "${test_compile_command}")
string(REPLACE " " ";" test_compile_command "${test_compile_command}")
execute_process(
COMMAND ${test_compile_command}
RESULT_VARIABLE result
OUTPUT_VARIABLE TEST_OUTPUT
ERROR_VARIABLE TEST_ERROR
)
CHECK_COMPILER_FLAG_COMMON_PATTERNS(_CheckCCompilerFlag_COMMON_PATTERNS)
set(ERRORS_FOUND OFF)
foreach(var ${_CheckCCompilerFlag_COMMON_PATTERNS})
if("${var}" STREQUAL "FAIL_REGEX")
continue()
endif()
if("${TEST_ERROR}" MATCHES "${var}" OR "${TEST_OUTPUT}" MATCHES "${var}")
set(ERRORS_FOUND ON)
endif()
endforeach()
if(result EQUAL 0 AND NOT ERRORS_FOUND)
set(${output} True PARENT_SCOPE)
else()
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Testing compiler for supporting " ${ARGN} ":\n"
"Command: ${test_compile_command}\n"
"${TEST_OUTPUT}\n${TEST_ERROR}\n${result}\n")
set(${output} False PARENT_SCOPE)
endif()
endfunction()
function(builtin_check_c_compiler_flag flag output)
if(NOT DEFINED ${output})
message(STATUS "Performing Test ${output}")
try_compile_only(result FLAGS ${flag})
set(${output} ${result} CACHE INTERNAL "Compiler supports ${flag}")
if(${result})
message(STATUS "Performing Test ${output} - Success")
else()
message(STATUS "Performing Test ${output} - Failed")
endif()
endif()
endfunction()
function(builtin_check_c_compiler_source output source)
if(NOT DEFINED ${output})
message(STATUS "Performing Test ${output}")
try_compile_only(result SOURCE ${source})
set(${output} ${result} CACHE INTERNAL "Compiler supports ${flag}")
if(${result})
message(STATUS "Performing Test ${output} - Success")
else()
message(STATUS "Performing Test ${output} - Failed")
endif()
endif()
endfunction()
|