I'm looking into gyp & gypi files in chromium. What's the role of cflags and ldflags?
What does below code mean?
'cflags': '<!#(<(pkg-config) --cflags gstreamer-0.10)',
'ldflags': '<!#(<(pkg-config) --libs-only-L --libs-only-other gstreamer-0.10)',
I had to study about makefile. and found :
cflags - this is used to set environment variable and configuration option for C compiler
ldflag - flag for ld linker
and there are other flags as below :
ARFLAGS - for ar achiver
ASFLAGS - for as assembler
CXXFLAGS - for c++ compiler
COFLAGS - for co utility
CPPFLAGS - for C preprocessor
FFLAGS - for Fortran compiler
LFLAGS - for lex
PFLAGS - for Pascal compiler
YFLAGS - for yacc
Related
We are using flatbuffer v1.3.0 and seeing error building flatc compiler.
Same error for flatbuffer version v1.3.0 to v1.12.1
Build is successful for version 2.0.0
Should we use a particular version of make to build the flatc compiler? If so how to do it?
Steps
git clone https://github.com/google/flatbuffers/tree/v1.3.0
cd flatbuffers
cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -Success
make --Error
Versions installed on MacOS BigSur Version 11.6
$ cmake --version
cmake version 3.19.4
CMake suite maintained and supported by Kitware (kitware.com/cmake).
$ make --version
GNU Make 3.81
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
This program built for i386-apple-darwin11.3.0
$ gcc --version
Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 13.0.0 (clang-1300.0.29.3)
Target: x86_64-apple-darwin20.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
$ cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release
CMake Warning:
No source or binary directory provided. Both will be assumed to be the
same as the current working directory, but note that this warning will
become a fatal error in future CMake releases.
CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
Compatibility with CMake < 2.8.12 will be removed from a future version of
CMake.
Update the VERSION argument <min> value or use a ...<max> suffix to tell
CMake that the project does not need compatibility with older versions.
-- The C compiler identification is AppleClang 13.0.0.13000029
-- The CXX compiler identification is AppleClang 13.0.0.13000029
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/abcd/Documents/FlatBuffer/flatbuffers
$ make
Scanning dependencies of target flatc
[ 2%] Building CXX object CMakeFiles/flatc.dir/src/idl_parser.cpp.o
In file included from /Users/abcd/Documents/FlatBuffer/flatbuffers/src/idl_parser.cpp:28:
In file included from /Users/abcd/Documents/FlatBuffer/flatbuffers/include/flatbuffers/idl.h:25:
/Users/abcd/Documents/FlatBuffer/flatbuffers/include/flatbuffers/flatbuffers.h:1086:25: error: definition of implicit copy constructor for 'TableKeyComparator<reflection::Object>' is deprecated because it has a user-declared copy assignment operator [-Werror,-Wdeprecated-copy]
TableKeyComparator& operator= (const TableKeyComparator&);
^
/Users/abcd/Documents/FlatBuffer/flatbuffers/include/flatbuffers/flatbuffers.h:1100:27: note: in implicit copy constructor for 'flatbuffers::FlatBufferBuilder::TableKeyComparator<reflection::Object>' first required here
std::sort(v, v + len, TableKeyComparator<T>(buf_));
^
/Users/abcd/Documents/FlatBuffer/flatbuffers/include/flatbuffers/flatbuffers.h:1113:12: note: in instantiation of function template specialization 'flatbuffers::FlatBufferBuilder::CreateVectorOfSortedTables<reflection::Object>' requested here
return CreateVectorOfSortedTables(v->data(), v->size());
^
/Users/abcd/Documents/FlatBuffer/flatbuffers/src/idl_parser.cpp:2008:35: note: in instantiation of function template specialization 'flatbuffers::FlatBufferBuilder::CreateVectorOfSortedTables<reflection::Object>' requested here```
Flatbuffer requires a specific version of clang to compile the 1.12.1.
Installing the required version.
sudo apt-get install clang-6.0 lld-6.0 clang-tidy-6.0
use update-alternatives to link the clang.
sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-6.0 10
sudo update-alternatives --install /usr/bin/clang++ clang++
/usr/bin/clang++-6.0 10
Good morning!
I'm rewriting this question because, after a lot of reading and try-fails, I go further on that but I get staked again.
What I'm trying to accomplice here is: Use Conan as a Package manager for the embedded device "Raspberry PICO" from my Mac (with CLion)
The change from the previous question is that now I'm creating a package and I do not use only the "standalone" packages manager.
This "package" is on github.com. To install and try to compile it, you will need also the Pico SDK.
Some facts:
The new c++ project without Conan but with SDK is compiling and working on an embedded device.
The Conan project without Pico SDK is compiling correctly.
I really tried every possible configuration on the profile file and there are two mainly configuration profiles that brings to two different errors during build:
The first one is without any environments. This is because on CLion I'm not adding any environment and the project itself (without conan, but oblivious with SDK for pico) is builder correctly.
[settings]
os_build=Macos
arch_build=x86_64
os=Linux
arch=armv7
# os=Macos
# arch=x86_64
# compiler=apple-clang
compiler=gcc
# compiler.version=12.0
compiler.version=9.2
# compiler.libcxx=libc++
compiler.libcxx=libstdc++
build_type=Release
[options]
[build_requires]
[env]
ps. The commented lines are additional tests that resolve on the same result after conan build ..
The error is this:
jure.prah#MacBook-Pro-di-Jure conan-blink-mosfet % conan build .
Using lockfile: '/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/conan.lock'
Using cached profile from lockfile
conanfile.py (blink/0.1): Calling build()
conanfile.py (blink/0.1): CMake command: cmake -G "Unix Makefiles" -DCMAKE_TOOLCHAIN_FILE="/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/generators/conan_toolchain.cmake" -DCMAKE_INSTALL_PREFIX="/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/package" "/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/src"
Using PICO_SDK_PATH from environment ('/Users/jure.prah/CLionProjects/pico-sdk')
PICO_SDK_PATH is /Users/jure.prah/CLionProjects/pico-sdk
Defaulting PICO_PLATFORM to rp2040 since not specified.
-- Defaulting build type to 'Release' since not specified.
Using Conan toolchain through /Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/generators/conan_toolchain.cmake.
-- Conan toolchain: Setting CMAKE_POSITION_INDEPENDENT_CODE=ON (options.fPIC)
-- Conan toolchain: Setting BUILD_SHARED_LIBS= OFF
-- The C compiler identification is AppleClang 12.0.5.12050022
-- The CXX compiler identification is AppleClang 12.0.5.12050022
-- The ASM compiler identification is Clang
-- Found assembler: /Library/Developer/CommandLineTools/usr/bin/cc
-- Detecting C compiler ABI info
Using Conan toolchain through .
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
Using Conan toolchain through .
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
Defaulting PICO target board to pico since not specified.
Using board configuration from /Users/jure.prah/CLionProjects/pico-sdk/src/boards/include/boards/pico.h
-- Found Python3: /usr/local/Frameworks/Python.framework/Versions/3.9/bin/python3.9 (found version "3.9.6") found components: Interpreter
TinyUSB available at /Users/jure.prah/CLionProjects/pico-sdk/lib/tinyusb/src/portable/raspberrypi/rp2040; adding USB support.
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/Release
conanfile.py (blink/0.1): CMake command: cmake --build '/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/Release'
[ 25%] Building CXX object CMakeFiles/blink.dir/blink.cpp.o
[ 50%] Linking CXX static library libblink.a
[ 50%] Built target blink
Scanning dependencies of target bs2_default
[ 75%] Building ASM object pico-sdk/src/rp2_common/boot_stage2/CMakeFiles/bs2_default.dir/compile_time_choice.S.o
/Users/jure.prah/CLionProjects/pico-sdk/src/rp2_common/boot_stage2/boot2_w25q080.S:89:1: error: unknown directive
.syntax unified
^
/Users/jure.prah/CLionProjects/pico-sdk/src/rp2_common/boot_stage2/boot2_w25q080.S:90:1: error: unknown directive
.cpu cortex-m0plus
^
/Users/jure.prah/CLionProjects/pico-sdk/src/rp2_common/boot_stage2/boot2_w25q080.S:91:1: error: unknown directive
.thumb
^
/Users/jure.prah/CLionProjects/pico-sdk/src/rp2_common/boot_stage2/boot2_w25q080.S:93:15: error: unexpected token in '.section' directive
.section .text
^
/Users/jure.prah/CLionProjects/pico-sdk/src/rp2_common/boot_stage2/boot2_w25q080.S:101:1: error: unknown directive
.type _stage2_boot,%function
^
/Users/jure.prah/CLionProjects/pico-sdk/src/rp2_common/boot_stage2/boot2_w25q080.S:102:1: error: unknown directive
.thumb_func
^
/Users/jure.prah/CLionProjects/pico-sdk/src/rp2_common/boot_stage2/boot2_w25q080.S:104:11: error: unknown token in expression
push {lr}
^
[...]
^
/Users/jure.prah/CLionProjects/pico-sdk/src/rp2_common/boot_stage2/boot2_w25q080.S:285:1: error: unknown directive
.ltorg
^
make[2]: *** [pico-sdk/src/rp2_common/boot_stage2/CMakeFiles/bs2_default.dir/compile_time_choice.S.o] Error 1
make[1]: *** [pico-sdk/src/rp2_common/boot_stage2/CMakeFiles/bs2_default.dir/all] Error 2
make: *** [all] Error 2
ERROR: conanfile.py (blink/0.1): Error in build() method, line 40
cmake.build()
ConanException: Error 2 while executing cmake --build '/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/Release'
The second profile configuration is based on the example from conan.com (thanks to #uilianres) and sets the environments.:
toolchain_path=/usr/local/bin
toolchain=arm-none-eabi
[settings]
os_build=Macos
arch_build=x86_64
#os=Macos
#arch=x86_64
os=Linux
arch=armv7
compiler=apple-clang
# compiler=gcc
compiler.version=12.0
# compiler.version=9.2
compiler.libcxx=libc++
# compiler.libcxx=libstdc++
build_type=Release
[options]
[build_requires]
[env]
CONAN_CMAKE_FIND_ROOT_PATH=$toolchain_path/
AR=$toolchain-ar
AS=$toolchain-as
CC=$toolchain-gcc
CXX=$toolchain-g++
STRIP=$toolchain-strip
Using command conan build . resolve on different error:
jure.prah#MacBook-Pro-di-Jure conan-blink-mosfet % conan build .
Using lockfile: '/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/conan.lock'
Using cached profile from lockfile
conanfile.py (blink/0.1): Calling build()
conanfile.py (blink/0.1): CMake command: cmake -G "Unix Makefiles" -DCMAKE_TOOLCHAIN_FILE="/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/generators/conan_toolchain.cmake" -DCMAKE_INSTALL_PREFIX="/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/package" "/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/src"
Using PICO_SDK_PATH from environment ('/Users/jure.prah/CLionProjects/pico-sdk')
PICO_SDK_PATH is /Users/jure.prah/CLionProjects/pico-sdk
Defaulting PICO_PLATFORM to rp2040 since not specified.
-- Defaulting build type to 'Release' since not specified.
Using Conan toolchain through /Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/generators/conan_toolchain.cmake.
-- Conan toolchain: Setting CMAKE_POSITION_INDEPENDENT_CODE=ON (options.fPIC)
-- Conan toolchain: Setting BUILD_SHARED_LIBS= OFF
-- The C compiler identification is GNU 9.2.1
-- The CXX compiler identification is GNU 9.2.1
-- The ASM compiler identification is GNU
-- Found assembler: /usr/local/bin/arm-none-eabi-gcc
-- Checking whether C compiler has -isysroot
-- Checking whether C compiler has -isysroot - yes
-- Checking whether C compiler supports OSX deployment target flag
-- Checking whether C compiler supports OSX deployment target flag - no
-- Detecting C compiler ABI info
Using Conan toolchain through .
-- Detecting C compiler ABI info - failed
-- Check for working C compiler: /usr/local/bin/arm-none-eabi-gcc
Using Conan toolchain through .
-- Check for working C compiler: /usr/local/bin/arm-none-eabi-gcc - broken
CMake Error at /usr/local/Cellar/cmake/3.21.0/share/cmake/Modules/CMakeTestCCompiler.cmake:66 (message):
The C compiler
"/usr/local/bin/arm-none-eabi-gcc"
is not able to compile a simple test program.
It fails with the following output:
Change Dir: /Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/Release/CMakeFiles/CMakeTmp
Run Build Command(s):/usr/bin/make -f Makefile cmTC_69910/fast && /Library/Developer/CommandLineTools/usr/bin/make -f CMakeFiles/cmTC_69910.dir/build.make CMakeFiles/cmTC_69910.dir/build
Building C object CMakeFiles/cmTC_69910.dir/testCCompiler.c.o
/usr/local/bin/arm-none-eabi-gcc -D_GLIBCXX_USE_CXX11_ABI=0 -O3 -DNDEBUG -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX11.3.sdk -fPIE -o CMakeFiles/cmTC_69910.dir/testCCompiler.c.o -c /Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/Release/CMakeFiles/CMakeTmp/testCCompiler.c
Linking C executable cmTC_69910
/usr/local/Cellar/cmake/3.21.0/bin/cmake -E cmake_link_script CMakeFiles/cmTC_69910.dir/link.txt --verbose=1
/usr/local/bin/arm-none-eabi-gcc -O3 -DNDEBUG -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX11.3.sdk -Wl,-search_paths_first -Wl,-headerpad_max_install_names CMakeFiles/cmTC_69910.dir/testCCompiler.c.o -o cmTC_69910
/usr/local/Cellar/arm-none-eabi-gcc/9-2019-q4-major/gcc/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld: warning: cannot find entry symbol arch_paths_first; defaulting to 0000000000008018
/usr/local/Cellar/arm-none-eabi-gcc/9-2019-q4-major/gcc/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/bin/ld: /usr/local/Cellar/arm-none-eabi-gcc/9-2019-q4-major/gcc/bin/../lib/gcc/arm-none-eabi/9.2.1/../../../../arm-none-eabi/lib/libc.a(lib_a-exit.o): in function `exit':
exit.c:(.text.exit+0x2c): undefined reference to `_exit'
collect2: error: ld returned 1 exit status
make[1]: *** [cmTC_69910] Error 1
make: *** [cmTC_69910/fast] Error 2
CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
CMakeLists.txt:5 (project)
-- Configuring incomplete, errors occurred!
See also "/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/Release/CMakeFiles/CMakeOutput.log".
See also "/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/Release/CMakeFiles/CMakeError.log".
ERROR: conanfile.py (blink/0.1): Error in build() method, line 39
cmake.configure()
ConanException: Error 1 while executing cmake -G "Unix Makefiles" -DCMAKE_TOOLCHAIN_FILE="/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/build/generators/conan_toolchain.cmake" -DCMAKE_INSTALL_PREFIX="/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/package" "/Users/jure.prah/CLionProjects/rpi-pico/conan-blink-mosfet/src"
Also here I did all the variants and tests, but everything leads to this error. Besides, I checked the toolchain paths and there are correct.
I'm completely lost now. :(
I would like to use CMAKE to compile a special piece of code in C99 with language extensions. Therefore I have to use a "custom" compiler and linker /your/path/to/compiler and /your/path/to/linker. How can I define the compiler and the linker command used by CMAKE?
EDIT:
I tried to define the compiler and linker as suggested by Equod:
set(CMAKE_C_COMPILER /your/path/to/compiler)
set(CMAKE_CUSTOM_LINKER /your/path/to/linker)
set(CMAKE_C_LINK_EXECUTABLE
"<CMAKE_CUSTOM_LINKER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
But CMAKE is still not taking it:
-- Building for: Visual Studio 15 2017
-- Selecting Windows SDK version 10.0.14393.0 to target Windows 10.0.18363.
-- The C compiler identification is MSVC 19.16.27040.0
-- The CXX compiler identification is MSVC 19.16.27040.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: C:/Programms/VisualStudio/2017/Professional/VC/Tools/MSVC/14.16.27023/bin/Hostx86/x86/cl.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: C:/Programms/VisualStudio/2017/Professional/VC/Tools/MSVC/14.16.27023/bin/Hostx86/x86/cl.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: C:/your/path/to/source/build
What I forgot to mention before, I am working on a Windows machine and the executable of th compiler and linker is in the PATH.
EDIT:
Here is my CMakeLists.txt
cmake_minimum_required(VERSION 3.10)
project(MyProject
VERSION 1.0
DESCRIPTION "This is MyProject"
LANGUAGES C
)
set(CMAKE_C_COMPILER my_compiler)
set(CMAKE_C_LINK_EXECUTABLE my_linker)
configure_file(include/myproject_config.h.in include/myproject_config.h)
set(HEADER_FILES include/main.h include/somefunc.h)
set(SOURCE_FILES src/main.c src/somefunc.c)
add_executable(MyProject ${HEADER_FILES} ${SOURCE_FILES})
target_include_directories(MyProject PUBLIC "${PROJECT_BINARY_DIR}" )
target_include_directories(MyProject PUBLIC "../include" )
P.S.: my_compiler and my_linker are in PATH of cmd and PowerShell.
EDIT:
I installed MinGW now. I have make in my PATH as well. I updated the CMakeLists.txt file above. The make command tries to compile the code now with:
my_compiler #CMakeFiles/MyProject.dir/includes_C.rsp -o CMakeFiles\MyProject.dir\src\main.c.obj -c "C:\mypath\main.c"
But this is not working because I need a command like:
my_compiler -I="../include" "C:\mypath\main.c"
What CMake commands do I need to configure such a behavior?
CMake as default C compiler uses CC environment variables. You can also specify a different compiler and linker setting CMake variables:
Compiler:
set(CMAKE_C_COMPILER /your/path/to/compiler)
Linker:
set(CMAKE_CUSTOM_LINKER /your/path/to/linker)
set(CMAKE_C_LINK_EXECUTABLE
"<CMAKE_CUSTOM_LINKER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
To better understand why linker settings are done in two steps I'd suggest taking a look at how those variables are managed internally by CMake:
CMake on github
Consider the following simple openMP program:
program hello
use OMP_LIB
implicit none
integer :: nthreads, tid
!$OMP PARALLEL PRIVATE(nthreads, tid)
tid = omp_get_thread_num()
nthreads = omp_get_num_threads()
! print *, "hello"
print *,"Thread:", tid, "of", nthreads
!$OMP END PARALLEL
end program hello
when i compile it as
gfortran -fopenmp hello.90 -o hello.x
I get output as:
Thread: 2 of 4
Thread: 1 of 4
Thread: 0 of 4
Thread: 3 of 4
as expected.
Now if i consider the following CMakeLists.txt file
cmake_minimum_required(VERSION 2.8.9)
project (hello Fortran)
enable_language(Fortran)
IF(NOT CMAKE_BUILD_TYPE)
message("NO BUILD TYPE PROVIDED")
message("DEFAULT BUILD TYPE SET TO 'Release'")
set(CMAKE_BUILD_TYPE 'Release')
ENDIF()
IF(${CMAKE_BUILD_TYPE} MATCHES RELEASE OR ${CMAKE_BUILD_TYPE} MATCHES Release)
message("MAKING RELEASE BUILD")
set(CMAKE_Fortran_FLAGS_RELEASE "-fopenmp")
message("FLAGS: ${CMAKE_Fortran_FLAGS_RELEASE}")
ENDIF()
add_executable(hello.x hello.f90)
Considering above file is right, it should add omp flag to make file and hence compile and run same, however
$ mkdir build; cd build
$ cmake ..
-- The Fortran compiler identification is GNU 6.1.0
-- Checking whether Fortran compiler has -isysroot
-- Checking whether Fortran compiler has -isysroot - yes
-- Checking whether Fortran compiler supports OSX deployment target flag
-- Checking whether Fortran compiler supports OSX deployment target flag - yes
-- Check for working Fortran compiler: /usr/local/bin/gfortran
-- Check for working Fortran compiler: /usr/local/bin/gfortran - works
-- Detecting Fortran compiler ABI info
-- Detecting Fortran compiler ABI info - done
-- Checking whether /usr/local/bin/gfortran supports Fortran 90
-- Checking whether /usr/local/bin/gfortran supports Fortran 90 - yes
NO BUILD TYPE PROVIDED
DEFAULT BUILD TYPE SET TO 'Release'
MAKING RELEASE BUILD
FLAGS: -fopenmp
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/user/Programs/omp/build
$
$ make
Scanning dependencies of target hello.x
[ 50%] Building Fortran object CMakeFiles/hello.x.dir/hello.f90.o
[100%] Linking Fortran executable hello.x
Undefined symbols for architecture x86_64:
"_omp_get_num_threads_", referenced from:
_MAIN__ in hello.f90.o
"_omp_get_thread_num_", referenced from:
_MAIN__ in hello.f90.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
make[2]: *** [hello.x] Error 1
make[1]: *** [CMakeFiles/hello.x.dir/all] Error 2
Which is same as missing -fopenmp flag. How to add it?
The set command for CMAKE_BUILD_TYPE take a "non-string" argument apparently.
Changing
set(CMAKE_BUILD_TYPE 'Release')
to
set(CMAKE_BUILD_TYPE Release)
solved the problem for me. I first dug into the cache system to understand why your setting would not work and there was no reason. I found a CMAKE_Fortran_FLAGS_'Release' entry in ccmake and looked again at the variable CMAKE_BUILD_TYPE in the docs, and it takes values empty, Debug, Release, RelWithDebInfo, MinSizeRel (which I understood as being unquoted).
I've to cross compile a 3rd party library which uses CMake.
In order to build something, I need to pass "-B path" flag to compiler.
foo.c :
void main(){}
Build command :
cross-gcc -B /path/to/somewhere -o foo.o foo.c
Without "-B path" option, the compiler simply does not work.
Hence I use the following lines in my cmake toolchain file :
SET(CMAKE_C_FLAGS "-B /path/to/somewhere")
SET(CMAKE_CXX_FLAGS "-B /path/to/somewhere")
But during the validation of compiler, CMake does not seem use the flags I set :
-- The C compiler identification is GNU
-- The CXX compiler identification is GNU
-- Check for working C compiler: /cross-path/cross-gcc
-- Check for working C compiler: /cross-path/cross-gcc -- broken
CMake Error at /usr/share/cmake-2.8/Modules/CMakeTestCCompiler.cmake:52 (MESSAGE):
The C compiler "cross-path/cross-gcc" is not able
to compile a simple test program.
....
....
/cross-path/cross-gcc -o CMakeFiles/cmTryCompileExec.dir/testCCompiler.c.o -c CMakeFiles/CMakeTmp/testCCompiler.c
When I invoke CMake second time, cross-gcc passes the simple compilation test but this time cross-g++ fails :
-- The C compiler identification is GNU
-- The CXX compiler identification is GNU
-- Check for working C compiler: /cross-path/cross-gcc
-- Check for working C compiler: /cross-path/cross-gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /cross-path/cross-g++
-- Check for working CXX compiler: /cross-path/cross-g++ -- broken
CMake Error at /usr/share/cmake-2.8/Modules/CMakeTestCXXCompiler.cmake:45 (MESSAGE):
The C++ compiler "/cross-path/cross-g++" is not
able to compile a simple test program.
....
....
/cross-path/cross-g++ -o CMakeFiles/cmTryCompileExec.dir/testCXXCompiler.cxx.o -c CMakeFiles/CMakeTmp/testCXXCompiler.cxx
And if I invoke CMake 3rd time, everything works fine with only a warning :
....
CMake Warning:
Manually-specified variables were not used by the project:
CMAKE_TOOLCHAIN_FILE
I'm using CMake 2.8.7 and aware that it is quite outdated but upgrade is not an option if this is the case.
Edit :
Toolchain file :
# this one is important
SET(CMAKE_SYSTEM_NAME Linux)
#this one not so much
SET(CMAKE_SYSTEM_VERSION 1)
SET(CMAKE_C_FLAGS "-B /path/to/somewhere")
SET(CMAKE_CXX_FLAGS "-B /path/to/somewhere")
# specify the cross compiler
SET(CMAKE_C_COMPILER /cross-path/cross-gcc)
SET(CMAKE_CXX_COMPILER /cross-path/cross-g++)
It looks that the problem of picking up the flags is very similar to one already discussed in SO in the past:
CMake cross-compiling: C flags from toolchain file ignored
Try the proposed solution, i.e. replace:
SET(CMAKE_C_FLAGS "-B /path/to/somewhere")
SET(CMAKE_CXX_FLAGS "-B /path/to/somewhere")
by
SET(CMAKE_C_FLAGS "-B /path/to/somewhere" CACHE STRING "" FORCE)
SET(CMAKE_CXX_FLAGS "-B /path/to/somewhere" CACHE STRING "" FORCE)
Try also to check if replacing your toolchain file with a new one that uses INCLUDE(CMakeForceCompiler) as mentioned in
http://www.vtk.org/Wiki/CMake_Cross_Compiling and
How can I make Cmake use specific compiler and flags when final compilation stage instead of detection? and
Cmake cross compile flags
INCLUDE(CMakeForceCompiler)
# this one is important
SET(CMAKE_SYSTEM_NAME Linux)
#this one not so much
SET(CMAKE_SYSTEM_VERSION 1)
SET(CMAKE_C_FLAGS "-B /path/to/somewhere")
SET(CMAKE_CXX_FLAGS "-B /path/to/somewhere")
# specify the cross compiler
CMAKE_FORCE_C_COMPILER(/cross-path/cross-gcc GNU)
CMAKE_FORCE_CXX_COMPILER(/cross-path/cross-g++ GNU)
...
has the same effect as the first hack. The second option seems a cleaner solution.