I have learned the basics of C++ programming and thought of ways how I could proceed, in order to practise. One thing that caught my interest was Web Scraping. Since I only knew BeautifulSoup, I searched for an alternative for C++ and found libXML for C++, however I'm trying to install it but don't seem to get it to work, since I barely have an idea on how to configure a CMake file. I'm using CLion as an IDE and Windows as my operating system, if it matters. My project folder is
C:\Users\Laurenz\Documents\Programming\untitled10
and the place where I've put the libXML library is
C:\Users\Laurenz\Documents\Programming\untitled10\libXML
however, I think the "main" directory is the one below (since it contains most of the Source files), but I'm not sure which of both I need to include.
C:\Users\Laurenz\Documents\Programming\untitled10\libXML\libxml++
I've searched around in the internet and found dozens of methods on how people include libraries, so I'm not sure which I need to use. What I currently have:
cmake_minimum_required(VERSION 3.6)
project(untitled10)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
set(SOURCE_FILES main.cpp)
add_executable(untitled10 ${SOURCE_FILES})
set(CMAKE_PREFIX_PATH "C:\\Users\\Laurenz\\Documents\\Programming\\untitled10\\libXML\\libxml++")
find_package(LibXML++ REQUIRED)
include_directories(${LibXML++_INCLUDE_DIRS})
set(LIBS ${LIBS} ${LibXML++_LIBRARIES})
target_link_libraries(untitled10 ${LIBS})
However, I get the following error message:
Error:By not providing "FindLibXML++.cmake" in CMAKE_MODULE_PATH this project has asked CMake to find a package configuration file provided by "LibXML++", but CMake did not find one.
Could not find a package configuration file provided by "LibXML++" with any of the following names:
LibXML++Config.cmake libxml++-config.cmake
Add the installation prefix of "LibXML++" to CMAKE_PREFIX_PATH or set "LibXML++_DIR" to a directory containing one of the above files. If "LibXML++" provides a separate development package or SDK, be sure it has been installed.
Could someone tell me how to properly configure LibXML? And maybe someone knows some resources where I can learn how CMake files work, because it confuses me a bit.
Thanks!
Related
I know this is a daft question, but I'm a beginner in visual studio/c++/cmake. I'm looking for a quick intro on how to use Qt5 installed via vcpk using:
vcpkg install qt5-base:x64-windows
This all installed ok and I got the following:
The package qt5-base:x64-windows provides CMake targets:
find_package(Qt5Concurrent CONFIG REQUIRED)
target_link_libraries(main PRIVATE Qt5::Concurrent Qt5::ConcurrentPrivate)
etc....
I just don't know what to do next! Before using libs in VS I just did an <#include> now I'm confronted with this lot... Pref. I want some sort of explanation at newbie level please.
If I add the line (at the top of a .cpp file just as a test):
#include <QtWidgets/QApplication>
It gives: Error (active) E1696 cannot open source file "QtWidgets/QApplication"
I'm new, I thought vcpkg took all the pain out of having to add all the libs etc to the project options? What do I need to do?
If you ran vcpkg integrate install and are just using VS you can just #include <Qt5/QtWidgets/QApplication>
If you are using CMake:
find_package(Qt5 COMPONENTS Widgets Concurrent CONFIG REQUIRED) and use target_link_libraries as described by the other answers. But you probably have to switch to #include <QApplication> since cmake file add the QtWidgets folder to the include folders.
For find_package to find the vcpkg build versions you have to specify the vcpkg.cmake toolchain file as the CMAKE_TOOLCHAIN_FILE=<vcpkgroot>/scripts/buildsystems/vcpkg.cmake (must be set in the first CMake call or rather early in the CMakeLists.txt before any project() call) and maybe also VCPKG_TARGET_TRIPLET=<sometriplet> (must also be defined early before CMAKE_TOOLCHAIN_FILE is loaded) if you installed Qt5 using one of the static triplets.
vcpkg is a cross-platform C++ package manager. Unlike winget, apt, and brew, vcpkg is designed for developers. For example, it builds the binaries from the source by default.
So it help user to have libraries installed in their projects and be able to find them.
You still need to learn how CMake canonical find_package() work IMHO.
Qt provide a cmake config package and usually, you'll need to use
find_package(Qt5Core REQUIRED)
find_package(Qt5Gui REQUIRED)
find_package(Qt5Widgets REQUIRED)
then
target_link_libraries(main PRIVATE ... Qt5::Core Qt5::Gui Qt5::Widgets)
ie rule of Thumb: you need a QtWidget/* include ? then target_link to Qt5::Widget etc...
Please note that CMake also provides (i.e. built-in) a few tools to ease Qt-related dev...
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTORCC ON)
-> you should try to read the CMake doc...
Until this point I have installed MinGW, CMake, and the Vulkan SDK. I also downloaded the GLFW precompiled binaries, GLM and PkgConfig according to this answer. Then I created a CMake project in CLion. This is the content of the CMakeLists.txt (which I got from here):
cmake_minimum_required(VERSION 3.16)
project(VulkanTest)
set(CMAKE_CXX_STANDARD 17)
add_executable(VulkanTest main.cpp)
find_package(Vulkan REQUIRED)
target_include_directories(${PROJECT_NAME} PUBLIC ${Vulkan_INCLUDE_DIRS})
target_link_libraries(${PROJECT_NAME} Vulkan::Vulkan)
find_package(PkgConfig REQUIRED)
pkg_search_module(GLM REQUIRED glm)
include_directories(${GLM_INCLUDE_DIRS})
target_link_libraries(${PROJECT_NAME} ${GLM_LIBRARY_DIRS})
find_package(glfw3 3.2 REQUIRED)
include_directories(${GLFW_INCLUDE_DIRS})
target_link_libraries(${PROJECT_NAME} ${GLFW_LIBRARIES})
The error message is as follows:
CMake Error at CMakeLists.txt:15 (find_package):
By not providing "Findglfw3.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "glfw3", but
CMake did not find one.
Could not find a package configuration file provided by "glfw3" (requested
version 3.2) with any of the following names:
glfw3Config.cmake
glfw3-config.cmake
Add the installation prefix of "glfw3" to CMAKE_PREFIX_PATH or set
"glfw3_DIR" to a directory containing one of the above files. If "glfw3"
provides a separate development package or SDK, be sure it has been
installed.
I also tried replacing find_package(glfw3 3.2 REQUIRED) with pkg_search_module(GLFW REQUIRED glfw3) as described on the GLFW website, but I get the errors "None of the required 'glfw3' found" and "None of the required 'glm' found".
First, the question, as this is likely what the all of the people visiting this thread are interested in. The problem demonstrated in the post seems very different from the question others probably want answered.
Answer For Visitors: You need to do three things in order to link with the Vulkan library on Windows when using cmake.
set(ENV{VULKAN_SDK} "Path/To/Vulkan/Version/Installation")
find_package(Vulkan REQUIRED)
target_link_libraries(target ${Vulkan_LIBRARIES})
The path should reference the specific version of Vulkan you are using. For me, this is C:/VulkanSDK/1.2.198.1, but it will be different for you depending on where Vulkan is installed and the version you want to use.
Don't forget to also add an include directory with something along the lines of target_include_directories(target PUBLIC "C:/VulkanSDK/1.2.198.1/Include") to avoid using absolute include paths for Vulkan headers in your code.
Explanation: The find_package command will search through a directory within your cmake installation for details about the package. For me, this directory is <cmake_install_dir>/share/cmake-3.18/Modules (3.18 should be replaced with the version you have installed.) In this directory you'll find a nice chunk of files named Find<PackageName>.cmake and FindVulkan.cmake should be among them. This file is what find_package is running under the hood. You'll notice a few instances of $ENV{VULKAN_SDK} in that file. This is why that VULKAN_SDK environment variable must be set before calling find_package. Cmake will throw errors if it isn't.
lizardsudoku's Problem (even though you probably already figured it out): As explained above, cmake is expecting to find a Findglfw3.cmake entry in that Modules directory and it didn't. Instead of creating one of those files yourself, it's easier to specify the glfw3 library directly in your CMakeLists.txt file like so.
list(APPEND CMAKE_PREFIX_PATH "path/to/lib/directory")
find_library(glfw NAMES glfw3 REQUIRED)
target_link_libraries(target ${glfw})
As someone mentioned, you want to make use of CMAKE_PREFIX_PATH to specify the directory the .lib is in. The find_library call can then search that directory for the glfw3.lib entry before it is specified as a linker input. Even though CMAKE_PREFIX_PATH affects what directories are searched through when find_package is used, the package file does not exist, hence the error does not change.
I am a complete beginner in C++ programming and have been advised to use CLion. I am trying to get the Boost package to work.
I found many posts and tutorials online, however they all skip the basics not known to someone who is not a programmer. Namely, there is no explanation of how to get from the moment you open a new project to using some function from the Boost package?
This is what I found to be lacking from previous answers:
Here we are advised to use live incboost live template, however there is no explanation on where to find it or how to use it.
Here seems like a clear tutorial, however it is aimed at Visual Studio, not CLion.
Here I am not sure what each of those files are and how to adjust them to match my case.
I have downloaded boost_1_70_0 from https://www.boost.org/users/download/ and it is now unzipped and saved in C:\...\boost_1_70_0.
Could someone please explain really simply how to get from a blank project to being able to use functions stored in boost?
Considering you are using CLion and it supports only CMake at this time and you have installed BOOST library in the default directory, then your CMakeLists.txt file should look like this. I have used it in linux operating system but it should be able in Windows too.
cmake_minimum_required(VERSION 3.13)
project(LaserCV)
set(CMAKE_CXX_STANDARD 17)
#local
file(GLOB SOURCES
*.hpp
*.cpp
)
add_executable(LaserCV ${SOURCE_FILES} ${SOURCES})
#add_executable(LaserCV main.cpp)
SET(CMAKE_CXX_FLAGS -pthread)
#boost
find_package(Boost REQUIRED)
target_link_libraries(LaserCV ${Boost_LIBRARIES})
include_directories(${Boost_INCLUDE_DIR})
Then simply include a header file for your wanted boost function, for example:
#include <boost/random.hpp>
I am using OpenCV with gcc and cmake. And I found a tutorial https://docs.opencv.org/3.4.0/db/df5/tutorial_linux_gcc_cmake.html .In the file CMakeLists.txt, there are some variables such as OpenCV and OpenCV_INCLUDE_DIRS.
cmake_minimum_required(VERSION 3.9)
project(VideoRecord)
set(CMAKE_CXX_STANDARD 11)
find_package(OpenCV REQUIRED)
include_directories(${OpenCV_INCLUDE_DIRS})
add_executable(VideoRecord main.cpp)
target_link_libraries(VideoRecord ${OpenCV_LIBS})
I want to know where to find these variables definition.
EDIT
Thanks #qbranchmaster's answer. I tried to search FindOpenCV.cmake but failed.
First try.
➜ ~ cmake --help-module-list | grep "FindOpen"
FindOpenACC
FindOpenAL
FindOpenCL
FindOpenGL
FindOpenMP
FindOpenSSL
FindOpenSceneGraph
FindOpenThreads
Another try.
➜ / find . "FindOpenCV.cmake"
In addition, my os is osx and I install cmake with brew. I comiple and install OpenCV manually.
These variables are part of the package config script shipping with OpenCV.
Note that find_package is a two-headed beast. The classic mode of operation is finding libraries through find-scripts. This is still the approach being used today for third-party libraries that are not aware of CMake. However, if your dependency is itself being built with CMake, it can provide a package config file instead, which allows for a more powerful mode of operation.
The idea here is that instead of you telling CMake how to find a dependency, the dependency itself tells CMake how clients can find it. This is the approach that is taken by libraries like OpenCV and Qt.
To answer your question, those variables are being set by the package config file in your local OpenCV installation, the template of which can be found in the OpenCV source code under cmake/templates/OpenCVConfig.cmake.in.
They are defined in CMake OpenCV module. CMake has numerous modules that aid in finding various libraries like OpenCV (FindOpenCV.cmake module).
Using this command you can get a list of modules that your CMake supports:
cmake --help-module-list
Some libraries come with their own *.cmake modules which should be installed in some system path. If you are using Ubuntu, your cmake modules should be localised in:
/usr/share/cmake/Modules/
If not, just search system for file FindOpenCV.cmake. In that file you will find these variables.
In general, you get variable names from the documentation or source code of the package you want to find.
Often you can derive the name to put into find_package from the provided FindFoo.cmake module file name, because "Foo" would be the name. The find module is either part of CMake or comes with the third-party library.
If there is no find module, some modules provide FooConfig.cmake files, where "Foo" is again the string to put into find_package.
If you have neither a find nor a config file, you need to find the library by other means, e.g., FindPkgConfig or find_library / find_file.
i'm trying to use SFML's library with CLion for a school project. I'm still not confident with programming and i am new to Clion.
After having download the library from SFML official site i read some tutorials, but i am a bit confused:
https://www.sfml-dev.org/tutorials/2.4/
Infact in the Getting Started section there are two voice that concern me: "Compiling with Cmake" and "..Code::Blocks (MinGW).
Well i tryed both but with no results, then i landed here.
I saw a topic that helped a bit configure SFML for clion (windows)
so i tried to follow the steps suggested.
The library is in C:\SFML-2.4.2
I copied FindSFML.cmake in SFMLProjects, located in C:\Users\Ludovico\ (the same path of the folder ClionProjects)
Then i gave it a try
cmake_minimum_required(VERSION 3.6)
project(provaSfml)
set(CMAKE_CXX_STANDARD 11)
set(SOURCE_FILES main.cpp)
add_executable(provaSfml ${SOURCE_FILES})
set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/SFMLProjects")
link_directories(C:/SFML-2.4.2/bin)
find_package(SFML REQUIRED system window graphics network audio)
if (SFML_FOUND)
include_directories(${SFML_INCLUDE_DIR})
target_link_libraries(provaSfml ${SFML_LIBRARIES})
endif ()
These are the error messages
"C:\Program Files (x86)\JetBrains\CLion 2016.3.2\bin\cmake\bin\cmake.exe" - DCMAKE_BUILD_TYPE=Debug -G "CodeBlocks - MinGW Makefiles" C:\Users\Ludovico\CLionProjects\provaSfml
CMake Error at CMakeLists.txt:10 (find_package):
By not providing "FindSFML.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "SFML", but
CMake did not find one.
Could not find a package configuration file provided by "SFML" with any of
the following names:
SFMLConfig.cmake
sfml-config.cmake
Add the installation prefix of "SFML" to CMAKE_PREFIX_PATH or set
"SFML_DIR" to a directory containing one of the above files. If "SFML"
provides a separate development package or SDK, be sure it has been
installed.
I'm thinking i did some mistakes even in the organization of folder...
can someone tell me some advice in order to clean the mess i have in my head?
What can i do to fix these problems?