I am trying to check thread_local(which is provided as __thread or __declspec(thread) ) feature in armcc.
CHECK_C_SOURCE_COMPILES("int main(){ static __thread int num; return 0;}" GCC_THREAD_LOCAL_AVAILABLE)
With my version of armcc, I am able to compile the source code in above cmake command without any error.
But cmake fails this test with following log:
Building C object CMakeFiles/cmTC_293ce.dir/src.o
/opt/ARM/DS-5//bin/armcc -DGCC_THREAD_LOCAL_AVAILABLE -o CMakeFiles/cmTC_293ce.dir/src.o -c /devdisk/users/gjha/code/aepe15_dryos_2nd/CMakeFiles/CMakeTmp/src.c
"/devdisk/users/gjha/code/aepe15_dryos_2nd/CMakeFiles/CMakeTmp/src.c", line 1: Warning: #177-D: variable "num" was declared but never referenced
int main(){ static __thread int num; return 0;}
^
/devdisk/users/gjha/code/aepe15_dryos_2nd/CMakeFiles/CMakeTmp/src.c: 1 warning, 0 errors
Linking C executable cmTC_293ce.elf
/opt/cmake394/bin/cmake -E cmake_link_script CMakeFiles/cmTC_293ce.dir/link.txt --verbose=1
/opt/ARM/DS-5/bin/armlink -DGCC_THREAD_LOCAL_AVAILABLE CMakeFiles/cmTC_293ce.dir/src.o -o cmTC_293ce.elf
Warning: L3910W: Old syntax, please use '-d'.
Fatal error: L3900U: Unrecognized option '-GCC_THREAD_LOCAL_AVAILABLE'.
Finished: 0 information, 1 warning, 0 error and 1 fatal error messages.
gmake[1]: *** [cmTC_293ce.elf] Error 1
Problem here is, cmake spills macro definition -DGCC_THREAD_LOCAL_AVAILABLE into linker command and armlink fails.
Please guide me how to avoid this macro definition spilling.
ARMCC version: 5.04
cmake version: 3.9.4
For GCC this problem does not occur and gnu-ld simply ignores the macro definition in the command line.
Source for the Module CMake/Modules/CheckCXXSourceCompiles.cmake is as following:
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
CheckCXXSourceCompiles
----------------------
Check if given C++ source compiles and links into an executable.
.. command:: check_cxx_source_compiles
::
check_cxx_source_compiles(code resultVar [FAIL_REGEX regex1 [regex2...]])
Check that the source supplied in ``code`` can be compiled as a C++ source
file and linked as an executable (so it must contain at least a ``main()``
function). The result will be stored in the internal cache variable specified
by ``resultVar``, with a boolean true value for success and boolean false for
failure. If ``FAIL_REGEX`` is provided, then failure is determined by
checking if anything in the output matches any of the specified regular
expressions.
The underlying check is performed by the :command:`try_compile` command. The
compile and link commands can be influenced by setting any of the following
variables prior to calling ``check_cxx_source_compiles()``:
``CMAKE_REQUIRED_FLAGS``
Additional flags to pass to the compiler. Note that the contents of
:variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>` and its associated
configuration-specific variable are automatically added to the compiler
command before the contents of ``CMAKE_REQUIRED_FLAGS``.
``CMAKE_REQUIRED_DEFINITIONS``
A :ref:`;-list <CMake Language Lists>` of compiler definitions of the form
``-DFOO`` or ``-DFOO=bar``. A definition for the name specified by
``resultVar`` will also be added automatically.
``CMAKE_REQUIRED_INCLUDES``
A :ref:`;-list <CMake Language Lists>` of header search paths to pass to
the compiler. These will be the only header search paths used by
``try_compile()``, i.e. the contents of the :prop_dir:`INCLUDE_DIRECTORIES`
directory property will be ignored.
``CMAKE_REQUIRED_LIBRARIES``
A :ref:`;-list <CMake Language Lists>` of libraries to add to the link
command. These can be the name of system libraries or they can be
:ref:`Imported Targets <Imported Targets>` (see :command:`try_compile` for
further details).
``CMAKE_REQUIRED_QUIET``
If this variable evaluates to a boolean true value, all status messages
associated with the check will be suppressed.
The check is only performed once, with the result cached in the variable
named by ``resultVar``. Every subsequent CMake run will re-use this cached
value rather than performing the check again, even if the ``code`` changes.
In order to force the check to be re-evaluated, the variable named by
``resultVar`` must be manually removed from the cache.
#]=======================================================================]
include_guard(GLOBAL)
macro(CHECK_CXX_SOURCE_COMPILES SOURCE VAR)
if(NOT DEFINED "${VAR}")
set(_FAIL_REGEX)
set(_key)
foreach(arg ${ARGN})
if("${arg}" MATCHES "^(FAIL_REGEX)$")
set(_key "${arg}")
elseif(_key)
list(APPEND _${_key} "${arg}")
else()
message(FATAL_ERROR "Unknown argument:\n ${arg}\n")
endif()
endforeach()
set(MACRO_CHECK_FUNCTION_DEFINITIONS
"-D${VAR} ${CMAKE_REQUIRED_FLAGS}")
if(CMAKE_REQUIRED_LIBRARIES)
set(CHECK_CXX_SOURCE_COMPILES_ADD_LIBRARIES
LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
else()
set(CHECK_CXX_SOURCE_COMPILES_ADD_LIBRARIES)
endif()
if(CMAKE_REQUIRED_INCLUDES)
set(CHECK_CXX_SOURCE_COMPILES_ADD_INCLUDES
"-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
else()
set(CHECK_CXX_SOURCE_COMPILES_ADD_INCLUDES)
endif()
file(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx"
"${SOURCE}\n")
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Performing Test ${VAR}")
endif()
try_compile(${VAR}
${CMAKE_BINARY_DIR}
${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx
COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
${CHECK_CXX_SOURCE_COMPILES_ADD_LIBRARIES}
CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
"${CHECK_CXX_SOURCE_COMPILES_ADD_INCLUDES}"
OUTPUT_VARIABLE OUTPUT)
foreach(_regex ${_FAIL_REGEX})
if("${OUTPUT}" MATCHES "${_regex}")
set(${VAR} 0)
endif()
endforeach()
if(${VAR})
set(${VAR} 1 CACHE INTERNAL "Test ${VAR}")
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Performing Test ${VAR} - Success")
endif()
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
"Performing C++ SOURCE FILE Test ${VAR} succeeded with the following output:\n"
"${OUTPUT}\n"
"Source file was:\n${SOURCE}\n")
else()
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Performing Test ${VAR} - Failed")
endif()
set(${VAR} "" CACHE INTERNAL "Test ${VAR}")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Performing C++ SOURCE FILE Test ${VAR} failed with the following output:\n"
"${OUTPUT}\n"
"Source file was:\n${SOURCE}\n")
endif()
endif()
endmacro()
If I update the try_compile command in the module as following, I am able to check C++ features with armcc without any error.
try_compile(${VAR}
${CMAKE_BINARY_DIR}
${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx
COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
${CHECK_CXX_SOURCE_COMPILES_ADD_LIBRARIES}
"${CHECK_CXX_SOURCE_COMPILES_ADD_INCLUDES}"
OUTPUT_VARIABLE OUTPUT)