Statically linking GLEW from source with cmake - c++

I am somewhat new to cmake and completely new to glew, glfw, and the like. I'm following a youtube channel to learn more about game engines and programming.
My problem is linking the static glew library in my project using cmake.
First, I start with the glew source code from http://mcs.une.edu.au/doc/glew-devel/index.html.
I compile it by:
cd build; cmake ./cmake; make glew_s
This adds a lib directory into the build directory with libGLEW.a
A shortened version of my CMakeLists.txt looks like:
cmake_minimum_required (VERSION 3.5 FATAL_ERROR)
project (TestProject CXX)
set(CMAKE_CXX_FLAGS "-std=c++11")
###########################
# GLEW
###########################
add_subdirectory(${CMAKE_SOURCE_DIR}/Dependencies/GLEW)
target_link_libraries(${PROJECT_NAME} glew)
and in Dependencies/GLEW I have another CMakeLists.txt:
# Add glew source and header files
file(GLOB_RECURSE glew-lib ${CMAKE_CURRENT_SOURCE_DIR}/lib/*)
file(GLOB_RECURSE glew-headers ${CMAKE_CURRENT_SOURCE_DIR}/include/GL/*)
add_library(glew ${glew-lib} ${glew-headers})
target_include_directories(glew PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/include/GL")
I put a copy of the libGLEW.a file into the lib directory and the include directory is copied from the glew source code include directory. It holds the GL directory, which contains the header files glew.h, wglew.h, eglew.h, and glxew.h.
When I run cmake I get the error:
CMake Error: Cannot determine link language for target "glew".
CMake Error: CMake can not determine linker language for target: glew
The glew source code also has a src directory with glew.c in it, but if I put it in the libs directory and include it in the Dependencies/GLEW/CMakeLists.txt like:
# Add glew source and header files
file(GLOB_RECURSE glew-lib ${CMAKE_CURRENT_SOURCE_DIR}/lib/*.c)
file(GLOB_RECURSE glew-headers ${CMAKE_CURRENT_SOURCE_DIR}/include/GL/*)
add_library(glew ${glew-lib} ${glew-headers})
target_include_directories(glew PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/include")
I get the error:
CMake Error: Error required internal CMake variable not set, cmake may
be not be built correctly.
Missing variable is: CMAKE_C_COMPILE_OBJECT
CMake Error: Error required internal CMake variable not set, cmake may
be not be built correctly.
Missing variable is: CMAKE_C_CREATE_STATIC_LIBRARY
Lastly, I have tried just including the glew.c and headers in the root CMakeLists.txt like:
#########################
# GLEW
#########################
include_directories("${CMAKE_SOURCE_DIR}/Dependencies/GLEW/lib/")
include_directories("${CMAKE_SOURCE_DIR}/Dependencies/GLEW/include/GL/")
Here cmake will finish, but it won't be able to compile, saying classes do not name a type and/or are not declared in this scope.
Any help would be appreciated. I was under the impression that the libGLEW.a was the static library, and all I would have to do is link and compile it along with the headers, but that did not work.

First of all, I forgot to use
make install
after using make the first time, so I was using the incorrect libGLEW.a file.
After including the proper libGLEW.a file, my directory structure had
./Dependencies/GLEW/include/GL/*.h //header files
./Dependencies/GLEW/lib/libGLEW.a //source file
Finally, the TopLevel CMakeLists.txt is changed to include:
add_library(glew STATIC IMPORTED GLOBAL)
set_target_properties(glew PROPERTIES IMPORTED_LOCATION ${CMAKE_SOURCE_DIR}/Dependencies/GLEW/lib/libGLEW.a )
set_target_properties(glew PROPERTIES INCLUDE_DIRECTORIES ${CMAKE_SOURCE_DIR}/Dependencies/GLEW/include )
If I want to include the library from a lower CMakeLists.txt such as /Dependencies/GLEW/CMakeLists.txt Then I would have to first export the library from there and then import it at the topLevel CMakeLists.txt file.
Now, in order to use glew headers in my project I can just use #include .

Related

C++ include library in Cmake project

I am attempting to integrate a C++ library I downloaded into a new project using CMake.
I downloaded the library ("downloaded_library"), created the build folder, and inside of it ran cmake .. and make. These both ran successfully, and than I navigated to the build folder and ran ./example to run the example file that came with the library. This also was successful, and so I hoped to add it to another project.
I added this working project into the 'libraries' folder of the following directory structure:
project
-libraries
-downloaded_library
-build
-include
-downloaded_lib
-downloaded_lib.h
-src
-examples
-example.cpp
-CMakeLists.txt
-src
-main.cpp
-build
-CMakeLists.txt
I hope to run the same code that ran in example.cpp in main.cpp, but I have been unable to get the import working. I navigate to the build folder and cmake .. runs successfully, but 'make' fails with an import error (fatal error on the include line, can't find the header file). This makes sense, as I didn't expect the same include line to work (I copy and pasted example.cpp to main.cpp), but I'm not sure what to make that.
fatal error: downloaded_lib/downloaded_lib.h: No such file or directory
1 | #include "downloaded_lib/downloaded_lib.h"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
In this situation, what should my CMakeLists.txt contain, and what should my #include contain to be able to use the contents of this library in main.cpp in the same way I can in example.cpp?
EDIT---
I changed the package names above for simplicity sake, but the repository of 'downloaded_library' is the following: https://github.com/siposcsaba89/socketcan-cpp.
My top level CMakeLists.txt looks like this:
# Minimum version of CMake required to build this project
cmake_minimum_required(VERSION 3.0)
# Name of the project
project(projectname)
# Add all the source files needed to build the executable
add_executable(${PROJECT_NAME} src/main.cpp)
add_subdirectory(libraries/downloaded_library)
# Link the executable and the library together
target_link_libraries(${PROJECT_NAME} downloaded_library)
Edit 2-- (Here I will use the original package name, socketcan-cpp).
Top level CMakeLists.txt:
# Minimum version of CMake required to build this project
cmake_minimum_required(VERSION 3.0)
# Name of the project
project(socketcan_demo)
# Add all the source files needed to build the executable
add_executable(${PROJECT_NAME} src/main.cpp)
add_subdirectory("libraries/socketcan-cpp")
target_include_directories(${PROJECT_NAME} PUBLIC "libraries/socketcan-cpp/include")
When running make I get this error:
fatal error: socketcan_cpp/socketcan_cpp_export.h: No such file or directory
4 | #include <socketcan_cpp/socketcan_cpp_export.h>
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
So the top level CMakeLists is able to find the header file located in include, but that header file contains the line: #include <socketcan_cpp/socketcan_cpp_export.h> which references a file in a gen directory inside the build directory created by the library's CMakeLists.txt (https://github.com/siposcsaba89/socketcan-cpp/blob/master/CMakeLists.txt). And my top level package is unable to find it.
In order to include the header files from the downloaded library, you can add the following to the CMakeLists.txt file:
find_library(downloaded_lib
NAMES downloaded_lib
HINTS "path to downloaded lib file")
if(NOT downloaded_lib)
message(FATAL_ERROR "downloaded_lib not found!")
endif()
target_include_directories(${PROJECT_EXECUTABLE} PUBLIC "path to download_lib.h")
target_link_libraries(${PROJECT_EXECUTABLE} ${downloaded_lib})
This includes the directory where the header file is located in addition to the library file.

Include external Library cmake

I want to use the SQLAPI library, i have copied all files in the include directory to usr/local/include/SQLAPI and all files from the lib directory to usr/local/lib. The lib files are named libsqlapi.a /libsqlapi.so and libsqlapiu.a /libsqlapiu.so .
My cmakeLists.txt looks like this:
project(gsl_test)
cmake_minimum_required(VERSION 2.8)
SET(CMAKE_CXX_FLAGS "-std=c++0x")
aux_source_directory(. SRC_LIST)
include_directories(usr/local/include)
link_directories(usr/local/lib)
add_executable(${PROJECT_NAME} ${SRC_LIST})
target_link_libraries(${PROJECT_NAME} libsqlapi)
I get the build/linker error: cannot find -llibsqlapi.
I did also try target_link_libraries(${PROJECT_NAME} sqlapi), but it gives me additional "skipping incompatible //usr/local/lib/libsqlapi.so"
(and the same for .a) with cannot find -lsqlapi
Ok, i'll change my edit to an answer:
The reason linker complained was the fact that you specified the library in the wrong manner. lib is just prefix - if you use target_link_libraries you use the rest of library name. Changing to
target_link_libraries(${PROJECT_NAME} sqlapi)
solved that issue. The error you receive now
skipping incompatible //usr/local/lib/libsqlapi.so
Is most probably caused by the fact that you have copied all the files from some pre-build package and it's not compatible with your system. You need to recompile the library on your own.

Compile issues: LIBUSB_1 with cmake project on Windows

First Attempt
In my cmake/c++ project I get the following error when compiling:
C:\local\projects\synergy-usb\synergy-through-usb-master>cmake .
You have called ADD_LIBRARY for library cryptopp without any source files. This typically indicates a problem with your CMakeLists.txt file
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
LIBUSB_1_INCLUDE_DIR
used as include directory in directory C:/local/projects/synergy-usb/synergy-through-usb-master/src/lib/arch
used as include directory in directory C:/local/projects/synergy-usb/synergy-through-usb-master/src/lib/net
LIBUSB_1_LIBRARY
linked by target "arch" in directory C:/local/projects/synergy-usb/synergy-through-usb-master/src/lib/arch
-- Configuring incomplete, errors occurred!
See also "C:/local/projects/synergy-usb/synergy-through-usb-master/CMakeFiles/CMakeOutput.log".
So I am missing libusb libraries.
Second Attempt
So now I have found a version of libusb_1 (libusbx-1.0.18-win) which includes the folders:
examples
include
MinGW32
MinGW64
MS32
MS64
I copied MS64/dll (windows 64-bit) contents and put it here:
C:\local\libs\libusbx
I added this path to my PATH variable and then tried to run cmake again:
C:>cd local\projects\synergy-usb\synergy-through-usb-master
C:\local\projects\synergy-usb\synergy-through-usb-master>cmake .
You have called ADD_LIBRARY for library cryptopp without any source files. This typically indicates a problem with your CMakeLists.txt file
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
LIBUSB_1_LIBRARY
linked by target "arch" in directory C:/local/projects/synergy-usb/synergy-through-usb-master/src/lib/arch
-- Configuring incomplete, errors occurred!
See also "C:/local/projects/synergy-usb/synergy-through-usb-master/CMakeFiles/CMakeOutput.log".
Now I am stuck again. I have no idea what it wants me to do. It knows where libusb is...
Edit
Here is the contects (part of) the CMakeLists.txt that has libusb in it:
find_package(libusb-1.0 REQUIRED)
set(inc
.
../base
../common
../mt
../platform
../synergy
${LIBUSB_1_INCLUDE_DIRS}
)
if (UNIX)
list(APPEND inc
../../..
../arch
)
endif()
include_directories(${inc})
add_library(arch STATIC ${src})
set(libs
../lib
${LIBUSB_1_LIBRARIES}
)
if (WIN32)
if (GAME_DEVICE_SUPPORT)
list(APPEND libs synxinhk)
endif()
endif()
target_link_libraries(arch ${libs})
Edit 2
I added the following lines into the findlibusb-1.0.cmake file:
set(LIBUSB_1_LIBRARY C:\\local\\libs\\libusbx\\libusb-1.0.dll)
message(STATUS "***********************************> LIBUSB_1_LIBRARY: ${LIBUSB_1_LIBRARY}")
Here is the output from that:
C:\local\projects\synergy-usb\synergy-through-usb-master>cmake .
-- ***********************************> LIBUSB_1_LIBRARY: C:\local\libs\libusbx\libusb-1.0.dll
-- Found libusb-1.0:
-- - Includes: C:/local/libs/libusbx
-- - Libraries: C:\local\libs\libusbx\libusb-1.0.dll
You have called ADD_LIBRARY for library cryptopp without any source files. This typically indicates a problem with your CMakeLists.txt file
-- Configuring done
CMake Error: CMake can not determine linker language for target: cryptopp
CMake Error: CMake can not determine linker language for target: cryptopp
CMake Error: CMake can not determine linker language for target: cryptopp
CMake Error: CMake can not determine linker language for target: cryptopp
-- Generating done
-- Build files have been written to: C:/local/projects/synergy-usb/synergy-through-usb-master
Still does not build, but this particular library seems to be added ok now :)
synergy had such approach to keep some 3rd party libs compressed in zip in ext subdirectory. synergy-through-usb though kept cmake way to specify include through -DLIBUSB_1_INCLUDE_DIR=... -DLIBUSB_1_LIBRARY=... for Windows.
So you just need go to 'ext' directory and uncompress its zip archives with libraries gtest, gmock and crypto.

Cmake configuration for multiple sub-libraries in a "packages" directory

Here is a sample project I am trying to build with a "Packages" directory which includes all the libraries to be used in the main code.
I am trying to keep my root cmake file as clean as possible and avoid relative path such as
include_directory(packages/lib1)
but I am struggling. Is there a way of including sub-directories of a directory for the purposes of header inclusion.
First a few minor remarks:
always name the CMake configuration files CMakeLists.txt (because of)
bookmark the documentation on CMake: https://cmake.org/documentation/
Sometimes it's not that easy to read, but very specific once you adopt your head to the "CMake world" ;-)
make yourself comfortable with the scope of CMake variables
include_directories(DIR1 [DIR2 [...]])
Tells CMake where the compiler should look for header files, i.e. -IDIR1 -IDIR2 ....
add_library(NAME [STATIC|SHARED] SOURCES)
This command creates the required compiler commands to create a static or shared library out of a given list of source files. No need to add in the header files. The make target will be called NAME and the library target is known to CMake as NAME.
add_subdirectory(DIR)
Tells CMake to look into DIR and parse the included CMakeLists.txt with all its content.
target_link_libraries(TARGET LIB1 [LIB2 [...]])
Tells CMake to instruct the linker to link LIB1, LIB2, etc. to the TARGET, i.e. -LLIB1 -LLIB2 .... TARGET is a CMake/make target previously defined/created with a call to add_{library,executable,custom_target}.
CMakeLists.txt:
include_directories(libraries)
# a header file in `libraries/lib1/foo.hpp` can be included
# in the whole CMake project by `#include "lib1/foo.hpp"`.
add_subdirectory(libraries)
add_subdirectory(tests)
libraries/CMakeLists.txt:
add_subdirectory(lib1)
add_subdirectory(lib2)
libraries/lib1/CMakeLists.txt:
add_library(lib1 STATIC ${LIB1_SOURCES})
libraries/lib2/CMakeLists.txt:
add_library(lib2 STATIC ${LIB2_SOURCES})
tests/CMakeLists.txt:
add_executable(tests ${TEST_SOURCES})
target_link_libraries(tests lib1 lib2)

Can't Include LibXML2 Files in a CMake C++ Project (using QtCreator IDE)

I'm working on a Cmake based C++ project in QtCreator. I am trying to use mlpack in my project, but as soon as I include the line #include <mlpack/core.hpp> to my only source file, I get an error pertaining to some libxml files that are included by mlpack/core.hpp:
In file included from /usr/local/include/mlpack/core/util/save_restore_utility.hpp:26:0,
from /usr/local/include/mlpack/core.hpp:171,
from /home/revinci/code/workspaces/qt_ws/Semantic_Perception/src/features_slic.cpp:18:
/usr/include/libxml2/libxml/parser.h:15:31: fatal error: libxml/xmlversion.h: No such file or directory
#include <libxml/xmlversion.h>
Now, I went into /usr/include/libxml2/libxml/ and found parser.h with the line #include <libxml/xmlversion.h> in it.
So, I saw that xmlversion.h and parser.h are in the same folder and tried a hack: I changed the #include <libxml/xmlversion.h> in parser.h to #include "xmlversion.h" only to get the following error:
In file included from /usr/include/libxml2/libxml/parser.h:15:0,
from /usr/local/include/mlpack/core/util/save_restore_utility.hpp:26,
from /usr/local/include/mlpack/core.hpp:171,
from /home/revinci/code/workspaces/qt_ws/Semantic_Perception/src/features_slic.cpp:18:
/usr/include/libxml2/libxml/xmlversion.h:13:31: fatal error: libxml/xmlexports.h: No such file or directory
#include <libxml/xmlexports.h>
Which is basically telling me that it can't find xmlexports.h (included by xmlversion.h). More importantly, xmlexports.h is in the same directory as xmlversion.h and parser.h!
I tried the solution mentioned here and installed libxml2-dev (again) and libxslt1-dev, but my problem wasn't solved.
I think this may have something to do with specifying my include paths correctly. I've tried to add /usr/include/libxml2 to the various path environment variables (PATH, INCLUDE_PATH and CPATH) that are present in my build environment in QtCreator, but to no avail. My CMakeLists.txt looks like this:
project(Semantic_Perception)
cmake_minimum_required(VERSION 2.8)
#Vigra Headers
include_directories(
include
)
file(GLOB_RECURSE VigraImpex include/impex/)
add_library(VigraImpex ${VigraImpex})
#LibXml2 Headers
find_package(LibXml2 REQUIRED)
#Armadillo Headedrs
find_package(Armadillo REQUIRED)
include_directories(${ARMADILLO_INCLUDE_DIRS})
#Boost Headers
find_package(Boost 1.54.0 REQUIRED)
add_executable(features_slic src/features_slic.cpp)
target_link_libraries(features_slic
VigraImpex
${ARMADILLO_LIBRARIES}
)
BTW: LibXml2, Armadillo and Boost are all dependencies of the library I am trying to use - mlpack. The command find_pakcage(mlpack) won't work because there is no Findmlpack.cmake file on my system anywhere, and I couldn't find one on the internet either.