I'm attempting to build an application using the AWS IOT device sdk for C++.
I was able to clone, build and install the library with CMake and Visual Studio. Now I'm trying to include the IotShadow library into my test application through CMake.
I've included the package in my CMakeLists.txt file as follows and included the path the library install through the CMAKE_PREFIX_PATH variable.
find_package(IotShadow-cpp REQUIRED)
target_link_libraries(TestApp IotShadow-cpp)
CMake runs fine and things seem to be setup. However when I attempt to build, the IotShadow header files are not found. I've confirmed that IotShadow-cpp_DIR is correct and that the header files do exist. I'm not sure where to go from here. Has anyone successfully used the SDK on windows?
Looks like the target for find_package is correct but the target for target_link_libraries needs to be AWS::IotShadow-cpp.
The following seemed to work for me:
find_package(IotShadow-cpp REQUIRED)
target_link_libraries(TestApp AWS::IotShadow-cpp)
Related
I have been trying to build a cmake c++ project. More specifically I am trying to use the gdal library in this project. In the CMakeLists.txt it says find_library(GDAL gdal) after doing some research i found, that visual studio can open cmake files by default as mention in this thread: https://learn.microsoft.com/en-us/cpp/build/cmake-projects-in-visual-studio?view=vs-2019.
Moreover, visual studio should also automatically include the gdal library once i have set it up with vcpkg correctly. I've already downloaded the x64-windows version of the library (vcpkg install gdal:x64-windows) in order to build for the right architecture and made it available via vcpkg integrate install on a user-wide scope.
After some trial and error, everything works fine now, the toolchain gets included accordingly and the library is found automatically, resulting in a configuration like that:
However, when trying to include the header files (or anything else; see code snippet), visual studio does not seem to link the library correctly as it will result in the error message: cannot open source file "gdal/gdal.h".
#include <gdal/ogrsf_frmts.h>
#include <gdal/gdal.h>
#include <gdal>
Where should I further investigate?
As others have said vcpkg integrate install and vcpkg.cmake don't work together the reason being:
set_target_properties(${name} PROPERTIES VS_USER_PROPS do_not_import_user.props)
set_target_properties(${name} PROPERTIES VS_GLOBAL_VcpkgEnabled false)
this deactivates the integration. The reason to deactivate the integration is so that you don't write an incomplete CMakeLists.txt (e.g. missing the include directory or not linking all required libraries).
As such replace find_library(GDAL gdal) with find_package(GDAL REQUIRED) and target_link_libraries against the target GDAL::GDAL (https://cmake.org/cmake/help/v3.17/module/FindGDAL.html)
I want to use uWebSockets(UWS) in my C++ project to transfer images over the network. The setup will be running on multiple operating systems, so the best way of creating the build files seemed like using CMake.
However, I am new to CMake and having a hard time building UWS. I don't understand how to start working with the official repository on Windows 10, so I found another repository that includes a CMakeFiles.txt file and some of the dependencies (openssl, zlib, libuv, but it doesn't include uSockets for some reason). The root CMakeFiles.txt includes:
[...]
find_package(OpenSSL REQUIRED)
find_package(ZLIB REQUIRED)
find_path(LIBUV_INCLUDE_DIR uv.h)
find_library(LIBUV_LIBRARY NAMES uv uv1)
[...]
It looks straightforward, but when I try to run mkdir build && cd build; cmake .., it cannot find OpenSSL. Here is the error message it spits out:
[...]
[cmake] Could not find a package configuration file provided by "OpenSSL" with any
[cmake] of the following names:
[cmake]
[cmake] OpenSSLConfig.cmake
[cmake] openssl-config.cmake
[...]
The above error message suggests that I need to set up a config file for each of these libraries. Yet, if I understand the find_package docs correctly, the command itself searches the library in various locations under the root folder. What kind of a folder structure does the find_package need in order to work?
More generally, am I wasting my time with this alternative repo? Is there a better way of using UWS with Windows 10? The official repo has a question about how to use it on Windows but I don't understand how that's an answer to the question. It only points to this page where it says any specific build systems will not officially be supported.
Any help would be appreciated.
Importing dependencies with add_subdirectory seems like a good way around this. When I ran cmake, I was receiving LNK2019 Error. I realized the following code snippet I found online was causing the problem, and the system works when I delete it.
if(MSVC)
set(CMAKE_EXE_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG} /NODEFAULTLIB:libcmt.lib /NODEFAULTLIB:msvcrt.lib")
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /SUBSYSTEM:WINDOWS")
endif()
I am trying to build a cross platform OpenGL application, which means building and including multiple libraries (glfw, glbinding, glm, etc.) Because my application is cross platform, it makes sense to use cmake to generate all the build scripts and not have to muck about with them myself. I am attempting to target Windows and Linux specifically.
A main feature that I need is that the libraries I need are not installed on the host system. Furthermore, they cannot be installed (due to administrative reasons). What I need is to build these libraries and then build my application.
I am mostly working on Windows using Visual Studio 2017, which has cmake support included. Currently, I have attempted to build these libraries myself, however I am having many issues getting find_package to do the right thing.
My directory structure looks like this:
project/
|-src/
|- my sources for my application
|-include/
|- my header files
|-external/
|-glfw-3.2.1/
|-glbinding-2.1.4/
|-glfw-build/
|-glbinidng-build/
So I am attempting to build the external libraries and use them in my application. I am also attempting to follow cmake best practices. My CMakeLists.txt currently looks like this:
cmake_minimum_required(VERSION 3.5)
project(glTestProj)
set(CMAKE_PREFIX_PATH "external/")
find_package(glfw3 3.2 REQUIRED)
find_package(glbinding REQUIRED)
add_executable(glTest src/main.cpp)
target_compile_features(glTest PRIVATE cxx_std_17)
target_compile_options(glTest PRIVATE -Wall -Wextra)
target_link_libraries(
glTest
glfw
glbinding::glbinding
)
The libraries in question (glfw and glbinding) both have instructions on including them via cmake, however I am running into this issue:
CMake Error at CMakeLists.txt:6 (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'm trying to create a CMake file that will detect the location of libxml2. From what see in examples and CMake documentation the find_package simply works. I'm running CLion on Ubuntu, the libxml2 is installed using apt-get, the FindLibXml2.cmake is located under CMake's modules. However CMake returns cryptic message:
Could not find a package configuration file provided by "FindLibXml2"
with any of the following names:
FindLibXml2Config.cmake
findlibxml2-config.cmake
Add the installation prefix of "FindLibXml2" to CMAKE_PREFIX_PATH or
set "FindLibXml2_DIR" to a directory containing one of the above
files. If "FindLibXml2" provides a separate development package or
SDK, be sure it has been installed.
Why it is trying to find this -config file? what I'm doing wrong?
CMake snippet
find_package(FindLibXml2 CONFIG REQUIRED)
I've also tried
find_package(FindLibXml2 REQUIRED)
Not sure which one to use
You should not have the Find in FindLibXml2; do:
find_package(LibXml2 REQUIRED)
As explained in the documentation:
CMake searches for a file called Find<package>.cmake
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.