/usr/share/cmake-3.10/Modules/CheckSymbolExists.cmake is in cmake-data 3.10.2-1ubuntu2.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | # Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
CheckSymbolExists
-----------------
Provides a macro to check if a symbol exists as a function, variable,
or macro in ``C``.
.. command:: check_symbol_exists
::
check_symbol_exists(<symbol> <files> <variable>)
Check that the ``<symbol>`` is available after including given header
``<files>`` and store the result in a ``<variable>``. Specify the list
of files in one argument as a semicolon-separated list.
``<variable>`` will be created as an internal cache variable.
If the header files define the symbol as a macro it is considered
available and assumed to work. If the header files declare the symbol
as a function or variable then the symbol must also be available for
linking (so intrinsics may not be detected).
If the symbol is a type, enum value, or intrinsic it will not be recognized
(consider using :module:`CheckTypeSize` or :module:`CheckCSourceCompiles`).
If the check needs to be done in C++, consider using
:module:`CheckCXXSymbolExists` instead.
The following variables may be set before calling this macro to modify
the way the check is run:
``CMAKE_REQUIRED_FLAGS``
string of compile command line flags
``CMAKE_REQUIRED_DEFINITIONS``
list of macros to define (-DFOO=bar)
``CMAKE_REQUIRED_INCLUDES``
list of include directories
``CMAKE_REQUIRED_LIBRARIES``
list of libraries to link
``CMAKE_REQUIRED_QUIET``
execute quietly without messages
#]=======================================================================]
macro(CHECK_SYMBOL_EXISTS SYMBOL FILES VARIABLE)
if(CMAKE_C_COMPILER_LOADED)
__CHECK_SYMBOL_EXISTS_IMPL("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.c" "${SYMBOL}" "${FILES}" "${VARIABLE}" )
elseif(CMAKE_CXX_COMPILER_LOADED)
__CHECK_SYMBOL_EXISTS_IMPL("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.cxx" "${SYMBOL}" "${FILES}" "${VARIABLE}" )
else()
message(FATAL_ERROR "CHECK_SYMBOL_EXISTS needs either C or CXX language enabled")
endif()
endmacro()
macro(__CHECK_SYMBOL_EXISTS_IMPL SOURCEFILE SYMBOL FILES VARIABLE)
if(NOT DEFINED "${VARIABLE}" OR "x${${VARIABLE}}" STREQUAL "x${VARIABLE}")
set(CMAKE_CONFIGURABLE_FILE_CONTENT "/* */\n")
set(MACRO_CHECK_SYMBOL_EXISTS_FLAGS ${CMAKE_REQUIRED_FLAGS})
if(CMAKE_REQUIRED_LIBRARIES)
set(CHECK_SYMBOL_EXISTS_LIBS
LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
else()
set(CHECK_SYMBOL_EXISTS_LIBS)
endif()
if(CMAKE_REQUIRED_INCLUDES)
set(CMAKE_SYMBOL_EXISTS_INCLUDES
"-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
else()
set(CMAKE_SYMBOL_EXISTS_INCLUDES)
endif()
foreach(FILE ${FILES})
string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT
"#include <${FILE}>\n")
endforeach()
string(APPEND CMAKE_CONFIGURABLE_FILE_CONTENT
"\nint main(int argc, char** argv)\n{\n (void)argv;\n#ifndef ${SYMBOL}\n return ((int*)(&${SYMBOL}))[argc];\n#else\n (void)argc;\n return 0;\n#endif\n}\n")
configure_file("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in"
"${SOURCEFILE}" @ONLY)
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for ${SYMBOL}")
endif()
try_compile(${VARIABLE}
${CMAKE_BINARY_DIR}
"${SOURCEFILE}"
COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
${CHECK_SYMBOL_EXISTS_LIBS}
CMAKE_FLAGS
-DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_SYMBOL_EXISTS_FLAGS}
"${CMAKE_SYMBOL_EXISTS_INCLUDES}"
OUTPUT_VARIABLE OUTPUT)
if(${VARIABLE})
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for ${SYMBOL} - found")
endif()
set(${VARIABLE} 1 CACHE INTERNAL "Have symbol ${SYMBOL}")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
"Determining if the ${SYMBOL} "
"exist passed with the following output:\n"
"${OUTPUT}\nFile ${SOURCEFILE}:\n"
"${CMAKE_CONFIGURABLE_FILE_CONTENT}\n")
else()
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Looking for ${SYMBOL} - not found")
endif()
set(${VARIABLE} "" CACHE INTERNAL "Have symbol ${SYMBOL}")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Determining if the ${SYMBOL} "
"exist failed with the following output:\n"
"${OUTPUT}\nFile ${SOURCEFILE}:\n"
"${CMAKE_CONFIGURABLE_FILE_CONTENT}\n")
endif()
endif()
endmacro()
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