I'm using mingw under Linux and I'm trying to compile for Windows. I'm using CMake and the ouptut should be an .exe file.
In my program I'm using a WinAPI call (RegisterPowerSettingNotification) which is found in user32.dll/user32.lib. I want to have my .exe independent of the user32.dll version (my .exe should run on Windows8/8.1/10).
My CmakeLists.txt:
include_directories(
${CMAKE_CURRENT_SOURCE_DIR}
${USBHID_HEADER}
)
#USER32 // Will find the user32.lib
find_library(USER32 user32)
list(APPEND USBHID_LIB_DEPS ${USER32})
find_path(USBHID_HEADER winuser.h)
list(APPEND INCLUDES ${USBHID_HEADER})
# add the executable
add_executable( myexe win_service.c resource.rc )
target_link_libraries( myexe LINK_PUBLIC ${USBHID_LIB_DEPS} )
set_target_properties( myexe PROPERTIES OUTPUT_NAME "MyExeService" )
install( TARGETS myexe DESTINATION bin)
When I'm compiling, I'm receiving a warning:
/.../win_service.c:182:27: warning: assignment makes pointer from integer without a cast [enabled by default]
lidcloseRegHandle = RegisterPowerSettingNotification(serviceStatusHandle, &GUID_LIDCLOSE_ACTION,...
and at linking time:
Linking C executable myexeservice.exe
CMakeFiles/myexeservice.dir/objects.a(win_service.c.obj):win_service.c:(.text+0x393): undefined reference to `RegisterPowerSettingNotification'
collect2: error: ld returned 1 exit status
I know that linking against a DLL makes no sense, but how can I fool the CMake to not look after RegisterPowerSettingNotification?
RegisterPowerSettingNotification is available starting Windows Vista. Compiling with MinGW under Linux, by default WINVER is 0x502 (Windows Server 2003): /usr/share/mingw-w64/include/_mingw.h, RegisterPowerSettingNotification is not defined.
Solution is to add, before any
#include <windows.h>
the definition for WINVER and _WIN32_WINNT.
#ifndef WINVER
#define WINVER 0x0600
#endif
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0600
#endif
Related
I'm building a small project that will output video. I'm trying to link to libswscale to convert RGBA to YUV420, however, the linker ld cannot successfully find libswscale symbols.
Undefined symbols for architecture x86_64:
"sws_getContext(int, int, AVPixelFormat, int, int, AVPixelFormat, int, SwsFilter*, SwsFilter*, double const*)", referenced from:
VideoWriter::writeFrame(std::__1::vector<char, std::__1::allocator<char> >) in video_writer.cpp.o
The offending line of code is this.
struct SwsContext *sws_ctx = sws_getContext(
avCodecContext->width, avCodecContext->height, AV_PIX_FMT_RGBA,
avCodecContext->width, avCodecContext->height, AV_PIX_FMT_YUV420P,
SWS_BILINEAR, NULL, NULL, NULL);
When I use -v on clang I see that the libswscale.dylib is being passed to ld. The dylib exists on the file system and is the same version as the library's header, as verified by otool.
"/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld" -demangle -lto_library /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/libLTO.dylib -no_deduplicate -dynamic -arch x86_64 -platform_version macos 10.15.0 11.1 -syslibroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk -o bin/main -search_paths_first -headerpad_max_install_names CMakeFiles/main.dir/src/main.cpp.o CMakeFiles/main.dir/src/window.cpp.o CMakeFiles/main.dir/src/video_writer.cpp.o -rpath /usr/local/lib /usr/local/lib/libGLEW.2.2.0.dylib /usr/local/lib/libboost_program_options-mt.dylib -framework OpenGL /usr/local/Cellar/sdl2_image/2.6.2/lib/libSDL2_image.dylib /usr/local/lib/libSDL2.dylib /usr/local/Cellar/ffmpeg/5.1.2/lib/libavcodec.dylib /usr/local/Cellar/ffmpeg/5.1.2/lib/libswscale.dylib /usr/local/Cellar/ffmpeg/5.1.2/lib/libavutil.dylib -lc++ -lSystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/12.0.0/lib/darwin/libclang_rt.osx.a -F/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/System/Library/Frameworks
This is my cmake file.
cmake_minimum_required(VERSION 3.19.2)
project(FragTool VERSION 1.0)
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/")
# --- c++ build settings --- #
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Weffc++ -O0")
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
set(CMAKE_BUILD_TYPE Debug)
# --- dependencies --- #
find_package(GLEW REQUIRED)
find_package(Boost 1.79.0 COMPONENTS program_options REQUIRED)
find_package(PkgConfig REQUIRED)
pkg_check_modules(LIBAV REQUIRED IMPORTED_TARGET
libavcodec
libswscale
libavutil
)
pkg_check_modules(LIBSDL2 REQUIRED IMPORTED_TARGET
sdl2
sdl2_image
)
set(EXECUTABLE main)
add_executable(${EXECUTABLE} src/main.cpp)
target_sources(${EXECUTABLE} PRIVATE
${CMAKE_SOURCE_DIR}/src/window.cpp
${CMAKE_SOURCE_DIR}/src/video_writer.cpp
)
target_include_directories(${EXECUTABLE} PRIVATE ${CMAKE_SOURCE_DIR}/src)
target_include_directories(${EXECUTABLE} PRIVATE ${GLEW_INCLUDE_DIRS})
target_link_libraries(${EXECUTABLE} PRIVATE GLEW::glew)
target_link_libraries(${EXECUTABLE} PRIVATE ${Boost_LIBRARIES})
target_link_libraries(${EXECUTABLE} PRIVATE PkgConfig::LIBSDL2)
target_link_libraries(${EXECUTABLE} PRIVATE PkgConfig::LIBAV)
I'm stumped as to what could be causing the linker to fail, given that it is being passed the libswscale dylib correctly as far as I can tell. I checked for any other versions of the dylib on the system that maybe are shadowing it, but didn't see any.
I figured this out. It was because the include statement needed to be wrapped with extern "C".
extern "C"
{
#include <libswscale/swscale.h>
}
I have compiled and installed with CMake the library SDL_bgi to a custom prefix /custom/prefix/. This library uses SDL2.
Now I want to use it in another project with the structure below but I get a linker error when I compile with make:
/usr/bin/c++ CMakeFiles/test.dir/test.cpp.o -o test -Wl,-rpath,/custom/prefix/lib: /custom/prefix/lib/libSDL_bgi.so
/usr/bin/ld: /custom/prefix/lib/libSDL_bgi.so: undefined reference to `SDL_DestroyWindow'
/usr/bin/ld: /custom/prefix/lib/libSDL_bgi.so: undefined reference to `SDL_CreateRenderer'
I have also written the file cmake/modules/FindSDL_bgi.cmake so that may be wrong as well.
If I compile with the following command I can compile correctly:
g++ test.cpp -I . -lSDL_bgi -lSDL2 -I /custom/prefix/include/ -L /custom/prefix/lib/
What am I doing wrongly?
Project structure:
cmake/modules/FindSDL_bgi.cmake
src/test/CMakeLists.txt
src/test/test.cpp
CMakeLists.txt
Libraries:
/usr/lib/libSDL.so
/usr/include/SDL.h
/custom/prefix/lib/libSDL_bgi.so
/custom/prefix/include/graphics.h
/custom/prefix/include/SDL2/libSDL_bgi.h
cmake/modules/FindSDL_bgi.cmake:
# - Try to find LibXml2
# Once done this will define
# SDL_BGI_FOUND - System has LibXml2
# SDL_BGI_INCLUDE_DIRS - The LibXml2 include directories
# SDL_BGI_LIBRARIES - The libraries needed to use LibXml2
# Hardcoded for now
set(SDL_BGI_PATH
/custom/prefix/
)
set(SDL_BGI_SEARCH_PATHS
/usr
/usr/local
/opt
${SDL_BGI_PATH}
)
find_path(SDL_BGI_INCLUDE_DIR graphics.h
HINTS
$ENV{SDL2DIR}
PATH_SUFFIXES include
PATHS ${SDL2_SEARCH_PATHS}
)
find_library(SDL_BGI_LIBRARY
NAMES SDL_bgi
HINTS
$ENV{SDL2DIR}
PATH_SUFFIXES lib64 lib
PATHS ${SDL2_SEARCH_PATHS}
)
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(SDL_bgi REQUIRED_VARS SDL_BGI_LIBRARY SDL_BGI_INCLUDE_DIR)
CMakeLists.txt
cmake_minimum_required(VERSION 3.15)
project(programmi_kennedy)
list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/modules")
set(COMPAT_HEADERS
${CMAKE_CURRENT_SOURCE_DIR}/include/
)
find_package(SDL_bgi REQUIRED)
add_subdirectory(src/test)
src/CMakeLists.txt:
add_executable(test test.cpp)
target_include_directories(test PUBLIC ${SDL_BGI_INCLUDE_DIR})
target_link_libraries(test PRIVATE ${SDL_BGI_LIBRARY})
install(TARGETS test DESTINATION bin)
/custom/prefix/include/graphics.h:
#include <SDL2/SDL_bgi.h>
What I was missing is to link to SDL2 with find_package(SDL2 REQUIRED) and link to SDL2::SDL2. (I did try to link to ${SDL2_LIBRARIES} but the syntax is different now). Thanks to #KamilCuk to point me to the right direction.
EDIT:
I changed the FindBGI_sdl.cmake module in order to search for the dependencies (SDL2) and link against them using the INTERFACE keyword. In this way the target test can link only against SDL_bgi and have the dependencies resolved automatically.
src/CMakeLists.txt:
add_executable(test test.cpp)
target_link_libraries(test PRIVATE SDL_bgi::SDL_bgi)
install(TARGETS test DESTINATION bin)
cmake/modules/FindSDL_bgi.cmake:
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
FindSDL_bgi
-------
Finds the SDL_bgi library.
Imported Targets
^^^^^^^^^^^^^^^^
This module provides the following imported targets, if found:
``SDL_bgi::SDL_bgi``
The SDL_bgi library
Result Variables
^^^^^^^^^^^^^^^^
This will define the following variables:
``SDL_bgi_FOUND``
True if the system has the SDL_bgi library.
``SDL_bgi_VERSION``
The version of the SDL_bgi library which was found.
``SDL_bgi_INCLUDE_DIRS``
Include directories needed to use SDL_bgi.
``SDL_bgi_LIBRARIES``
Libraries needed to link to SDL_bgi.
Cache Variables
^^^^^^^^^^^^^^^
The following cache variables may also be set:
``SDL_bgi_INCLUDE_DIR``
The directory containing ``foo.h``.
``SDL_bgi_LIBRARY``
The path to the SDL_bgi library.
#]=======================================================================]
find_package(SDL2 REQUIRED)
find_package(PkgConfig)
pkg_check_modules(PC_SDL_bgi QUIET SDL_bgi)
find_path(SDL_bgi_INCLUDE_DIR
NAMES graphics.h
PATHS ${PC_SDL_bgi_INCLUDE_DIRS}
)
find_library(SDL_bgi_LIBRARY
NAMES SDL_bgi
PATHS ${PC_SDL_bgi_LIBRARY_DIRS}
)
set(SDL_bgi_VERSION ${PC_SDL_bgi_VERSION})
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(SDL_bgi
FOUND_VAR SDL_bgi_FOUND
REQUIRED_VARS
SDL_bgi_LIBRARY
SDL_bgi_INCLUDE_DIR
VERSION_VAR SDL_bgi_VERSION
)
if(SDL_bgi_FOUND AND NOT TARGET SDL_bgi::SDL_bgi)
add_library(SDL_bgi::SDL_bgi UNKNOWN IMPORTED)
set_target_properties(SDL_bgi::SDL_bgi PROPERTIES
IMPORTED_LOCATION "${SDL_bgi_LIBRARY}"
INTERFACE_COMPILE_OPTIONS "${PC_SDL_bgi_CFLAGS_OTHER}"
INTERFACE_INCLUDE_DIRECTORIES "${SDL_bgi_INCLUDE_DIR}"
)
target_link_libraries(SDL_bgi::SDL_bgi INTERFACE SDL2::SDL2)
endif()
mark_as_advanced(
SDL_bgi_INCLUDE_DIR
SDL_bgi_LIBRARY
SDL2_DIR
)
Useful references:
https://pabloariasal.github.io/2018/02/19/its-time-to-do-cmake-right/
https://cmake.org/cmake/help/v3.17/manual/cmake-developer.7.html
I'm testing vcpkg (on macOS) with a CMake project.
Since not all vcpkg packages have CMake find modules, I'm trying with a package that doesn't have one: libuuid
This is the directory tree relative to libuuid I can see from the vcpkg root:
$ find packages/libuuid_x64-osx
packages/libuuid_x64-osx
packages/libuuid_x64-osx/include
packages/libuuid_x64-osx/include/uuid
packages/libuuid_x64-osx/include/uuid/uuid.h
packages/libuuid_x64-osx/BUILD_INFO
packages/libuuid_x64-osx/lib
packages/libuuid_x64-osx/lib/libuuid.a
packages/libuuid_x64-osx/CONTROL
packages/libuuid_x64-osx/debug
packages/libuuid_x64-osx/debug/lib
packages/libuuid_x64-osx/debug/lib/libuuid.a
packages/libuuid_x64-osx/share
packages/libuuid_x64-osx/share/libuuid
packages/libuuid_x64-osx/share/libuuid/copyright
Example program:
#include <iostream>
#include <uuid/uuid.h>
int main(int argc, char **argv)
{
std::cout << "Hello, world!" << std::endl;
return 0;
}
Example CMakeLists.txt
cmake_minimum_required(VERSION 3.13)
project(vcpkg_example_project)
add_executable(app app.cpp)
target_link_libraries(app uuid)
If I understand correctly, vcpkg's philosophy is not to provide missing CMake find-modules, but to simply have #include <libfoo/foo.h> work out of the box. And in fact the example above compiles fine. But fails to find -luuid:
$ cmake -DCMAKE_TOOCHAIN_FILE=/Users/me/Dev/vcpkg/scripts/buildsystems/vcpkg.cmake ..
...
$ cmake --build .
Scanning dependencies of target app
[ 50%] Building CXX object CMakeFiles/app.dir/app.cpp.o
[100%] Linking CXX executable app
ld: library not found for -luuid
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [app] Error 1
make[1]: *** [CMakeFiles/app.dir/all] Error 2
make: *** [all] Error 2
What am I missing?
Also, I see there is a installed/x64-osx/lib/libuuid.a. Shouldn't installed/x64-osx/lib automatically added as lib path by the toolchain cmake script?
I'd make a target out of uuid. From what you describe, most probably an Interface Library called uuid. You can add_target_include_directories and target_link_libraries for the headers and any libraries, and then add it to the rest of your project.
So something like this:
add_library(uuid INTERFACE)
if(${CMAKE_BUILD_TYPE} STREQUAL "Release")
find_library(LIBUUID uuid "${CMAKE_CURRENT_SOURCE_DIR}/packages/libuuid_x64-osx/lib/")
else()
find_library(LIBUUID uuid "${CMAKE_CURRENT_SOURCE_DIR}/packages/libuuid_x64-osx/debug/lib/")
endif()
target_link_libraries(uuid INTERFACE "${LIBUUID}")
target_include_directories(uuid SYSTEM INTERFACE "${CMAKE_CURRENT_SOURCE_DIR}/packages/libuuid_x64-osx/include")
I'd then do an add_subdirectory to the library's folder and link to uuid
I'm just starting to learn how to work with zeromq libraries and using them in different C++ projects.
The sample code that I wrote (actually copied from there tutorials)is this:
// file: main.cpp
// Hello World client in C++
// Connects REQ socket to tcp://localhost:5555
// Sends "Hello" to server, expects "World" back
//
#include <zmq.hpp>
#include <string>
#include <iostream>
int main ()
{
// Prepare our context and socket
zmq::context_t context (1);
zmq::socket_t socket (context, ZMQ_REQ);
std::cout << "Connecting to hello world server…" << std::endl;
socket.connect ("tcp://localhost:5555");
// Do 10 requests, waiting each time for a response
for (int request_nbr = 0; request_nbr != 10; request_nbr++) {
zmq::message_t request (5);
memcpy (request.data (), "Hello", 5);
std::cout << "Sending Hello " << request_nbr << "…" << std::endl;
socket.send (request);
// Get the reply.
zmq::message_t reply;
socket.recv (&reply);
std::cout << "Received World " << request_nbr << std::endl;
}
return 0;
}
and by building the output of this file with the command below:
g++ main.cpp -o test -lzmq
the file will be generated with no problem.
The problem that I have is that I want to build the file using CMake.Thus, I've written a CMakeLists.txt file as below:
cmake_minimum_required(VERSION 3.6)
project(test2)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -lzmq")
set(SOURCE_FILES main.cpp)
add_executable(test2 ${SOURCE_FILES})
The part that I thought will be enough to build the program is -lzmq but even with that piece included, I get the following error messages:
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::error_t::error_t()':
/usr/include/zmq.hpp:62: undefined reference to `zmq_errno'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::error_t::what() const':
/usr/include/zmq.hpp:66: undefined reference to `zmq_strerror'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::message_t::message_t()':
/usr/include/zmq.hpp:107: undefined reference to `zmq_msg_init'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::message_t::message_t(unsigned long)':
/usr/include/zmq.hpp:114: undefined reference to `zmq_msg_init_size'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::message_t::~message_t()':
/usr/include/zmq.hpp:129: undefined reference to `zmq_msg_close'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::message_t::data()':
/usr/include/zmq.hpp:180: undefined reference to `zmq_msg_data'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::context_t::context_t(int)':
/usr/include/zmq.hpp:204: undefined reference to `zmq_init'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::context_t::~context_t()':
/usr/include/zmq.hpp:225: undefined reference to `zmq_term'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::socket_t::socket_t(zmq::context_t&, int)':
/usr/include/zmq.hpp:251: undefined reference to `zmq_socket'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::socket_t::close()':
/usr/include/zmq.hpp:283: undefined reference to `zmq_close'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::socket_t::connect(char const*)':
/usr/include/zmq.hpp:314: undefined reference to `zmq_connect'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::socket_t::send(zmq::message_t&, int)':
/usr/include/zmq.hpp:321: undefined reference to `zmq_send'
/usr/include/zmq.hpp:324: undefined reference to `zmq_errno'
CMakeFiles/test2.dir/main.cpp.o: In function `zmq::socket_t::recv(zmq::message_t*, int)':
/usr/include/zmq.hpp:331: undefined reference to `zmq_recv'
/usr/include/zmq.hpp:334: undefined reference to `zmq_errno'
Should I set another kind of variable in the CMake file or have I installed the library in a wrong directory? or is there anything else that I should have mentioned?
and The system witch I'm working on is Ubuntu 14.04
CMake doesn't include direct support for 0mq and 0mq doesn't include direct support for CMake. But, 0mq does support pkg-config and we can use this to help us. Since you mentioned that you're on Ubuntu 14.04, make sure you've done sudo apt-get install libzmq3-dev to install the 0mq libraries, headers, and the pkg-config .pc file.
Then use the following CMakeLists.txt which I've modified from your version above. (I've commented all my changes inline.)
## i have cmake 3.5
cmake_minimum_required(VERSION 3.5)
project(test2)
## use this to globally use C++11 with in our project
set(CMAKE_CXX_STANDARD 11)
## load in pkg-config support
find_package(PkgConfig)
## use pkg-config to get hints for 0mq locations
pkg_check_modules(PC_ZeroMQ QUIET zmq)
## use the hint from above to find where 'zmq.hpp' is located
find_path(ZeroMQ_INCLUDE_DIR
NAMES zmq.hpp
PATHS ${PC_ZeroMQ_INCLUDE_DIRS}
)
## use the hint from above to find the location of libzmq
find_library(ZeroMQ_LIBRARY
NAMES zmq
PATHS ${PC_ZeroMQ_LIBRARY_DIRS}
)
set(SOURCE_FILES main.cpp)
add_executable(test2 ${SOURCE_FILES})
## add the include directory to our compile directives
target_include_directories(test2 PUBLIC ${ZeroMQ_INCLUDE_DIR})
## at the 0mq library to our link directive
target_link_libraries(test2 PUBLIC ${ZeroMQ_LIBRARY})
Now you can make your project.
❯ make
[ 50%] Building CXX object CMakeFiles/test2.dir/main.cpp.o
[100%] Linking CXX executable test2
[100%] Built target test2
If you want to see what's happening under the hood, do a verbose make.
❯ make VERBOSE=1
/usr/bin/cmake -H/home/nega/foo -B/home/nega/foo/build --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /home/nega/foo/build/CMakeFiles /home/nega/foo/build/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory '/home/nega/foo/build'
make -f CMakeFiles/test2.dir/build.make CMakeFiles/test2.dir/depend
make[2]: Entering directory '/home/nega/foo/build'
cd /home/nega/foo/build && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/nega/foo /home/nega/foo /home/nega/foo/build /home/nega/foo/build /home/nega/foo/build/CMakeFiles/test2.dir/DependInfo.cmake --color=
make[2]: Leaving directory '/home/nega/foo/build'
make -f CMakeFiles/test2.dir/build.make CMakeFiles/test2.dir/build
make[2]: Entering directory '/home/nega/foo/build'
[ 50%] Building CXX object CMakeFiles/test2.dir/main.cpp.o
/usr/bin/c++ -std=gnu++11 -o CMakeFiles/test2.dir/main.cpp.o -c /home/nega/foo/main.cpp
[100%] Linking CXX executable test2
/usr/bin/cmake -E cmake_link_script CMakeFiles/test2.dir/link.txt --verbose=1
/usr/bin/c++ CMakeFiles/test2.dir/main.cpp.o -o test2 /usr/lib/x86_64-linux-gnu/libzmq.so
make[2]: Leaving directory '/home/nega/foo/build'
[100%] Built target test2
make[1]: Leaving directory '/home/nega/foo/build'
/usr/bin/cmake -E cmake_progress_start /home/nega/foo/build/CMakeFiles 0
If you look at the compile line, you'll notice that
C++11 support was added (with the -std=gnu++11 flag)
There's no -I/path/to/zmq flag. That's because Ubuntu dumps zmq.hpp in to /usr/include and CMake is smart enough to know that is a default path, so it does nothing
If you look at the link line, you'll notice that libzmq.so has been included via it's full path. Some people don't like that (myself included) and prefer -L/lib/dir -lmylib instead. Using the full path is "the CMake way", and you'll actually come to appreciate it as you grow with CMake and use it for larger and more complicated projects (you still might not like it though.)
Also note, that since you're on Ubuntu we could have cheated and used dpkg -L libzmq3-dev to find the locations of the files we're interested in then added them to your original CMAKE_CXX_FLAGS line, but that's cheating and more importantly, not portable.
A cmake config file has been added to libzmq github repository Jan 7, 2017 here.
This is not included in the latest release (4.2.1) yet, but I belive it should be in the next release.
I have installed the head version using cmake and then installed cppzmq, which uses find_package(ZeroMQ REQUIRED) to locate libzmq. All worked like a charm.
EDIT: The cmake config file is included in release 4.2.2 here. Then it was moved to directory builds/cmake at release 4.2.4. I didn't test it again but find_package(ZeroMQ REQUIRED) should just work since ibzmq 4.2.2.
This works as well
cmake_minimum_required(VERSION 3.6)
project(test)
add_executable(c main.cpp)
target_link_libraries(c zmq)
cmake version 2.8.5
I am trying to compile my project using cmake. However, when i compile I don't think I am including the debug cflags i.e. -ggdb -D_DEBUG. As when I try and debug there is no debub info.
Is there any problem with the CMakeLists.txt files. I have 3 of them
# Mimimum version of cmake required
CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
# Name of project
PROJECT(sdp_creator C)
# Check for correct compiler
# Using C compiler GNUCXX for c++ compiler
IF(CMAKE_COMPILER_IS_GNUCC)
MESSAGE(STATUS "=== GCC C COMPILER DETECTED")
SET(CMAKE_C_FLAGS "-m32 -ggdb -D_DEBUG -Wextra -Wall -Wunreachable-code -O0 -D_LARGEFILE64_SOURCE")
ENDIF(CMAKE_COMPILER_IS_GNUCC)
# Using windows compiler i.e. msvc++
IF(WIN32)
MESSAGE(STATUS "=== MSVC COMPILER DETECTED")
ENDIF(WIN32)
# Location of directory where include files are kept
INCLUDE_DIRECTORIES($ENV{HOME}/projects/sdp_creator/src/sdp)
INCLUDE_DIRECTORIES($ENV{HOME}/projects/sdp_creator/src/apr/inc)
# Location of directory where libraries are kept
LINK_DIRECTORIES($ENV{HOME}/projects/sdp_creator/src/apr/lib)
# Add subdirectories
ADD_SUBDIRECTORY(driver)
ADD_SUBDIRECTORY(sdp)
building shared library:
# Create a shared library called libsdp from sdp.c
# NOTE: static is the default
# NOTE: the lib prefix is automatically added
ADD_LIBRARY(sdp SHARED sdp.c)
Creating executable:
# Add executable called sdp_creator from source file
ADD_EXECUTABLE(sdp_creator main.c)
# Link the sdp library and other libraries with the excutable
#if using windows compiler add additional windows libraries
IF(WIN32)
TARGET_LINK_LIBRARIES(sdp_creator libsdp ws2_32)
MESSAGE(STATUS "=== Linking executable with windows libraries")
ENDIF(WIN32)
# if using gcc compiler
# NOTE: no need to add the -l prefix i.e. -lsdp, no automatically
IF(CMAKE_COMPILER_IS_GNUCC)
TARGET_LINK_LIBRARIES(sdp_creator sdp apr-1)
MESSAGE(STATUS "=== Linking executable with posix libraries")
ENDIF(CMAKE_COMPILER_IS_GNUCC)
Many thanks for any advice,
If you're using the "Unix Makefiles" (or any Makefile-based) generator, set the variable CMAKE_BUILD_TYPE to "Debug"
cmake -DCMAKE_BUILD_TYPE=Debug ../src
That will automatically add the right definitions and flags for your compiler. You should not have to add any flags yourself.
With multi-configuration generators, (like Visual Studio and Xcode), CMAKE_BUILD_TYPE is ignored, because the choice of whether to build a Debug or Release configuration is left up to the developer at build-time, and is not known at CMake configure time.
You can check the exact steps used in make by setting VERBOSE=1. That will tell you if the flags were included or not.
cmake project_dir
make VERBOSE=1
You can also check the CMakeCache.txt to see what value is assigned to CMAKE_C_FLAGS variable.
you can use the CMAKE_C_FLAGS and CMAKE_CXX_FLAGS flags with -g0/1/2 (debug information flag for the compiler. -g2 is the highest information):
cmake ... -DCMAKE_C_FLAGS="-g2" -DCMAKE_CXX_FLAGS="-g2" ...
Another option, if unix Makefiles are used to build the project, is to set CMAKE_BUILD_TYPE in CMakeLists.txt file directly:
set(CMAKE_BUILD_TYPE Debug)
You can find more in
$ man cmakevars
Look for CMAKE_BUILD_TYPE