I am trying to write a C++ project using libressl. I have built the package and followed the instructions here however I have been unable to locate the header files (or any files from the make install actually) for the project.
I am fairly new to C++ development and I am not a professional programmer so there is a good chance I am doing this completely wrong. Is it even possible to use LibreSSL as a C++ library and if so what steps would I need to take to do so?
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I'm writing a C++ application in TensorFlow 1.6. I'm able to run Python files with no problems and have compiled the C++ examples that also run just fine, so I think I've set up TensorFlow correctly.
I've started a new project that builds with no errors using plain C++. I'm now trying to construct Placeholder(), the docs say I need to #include <array_ops.h>, but it can't be located during compile. I did sudo find / -name "array_ops.h" and the only match was a file in ~/.cache/bazel.
Is there an extra build/configure step needed to install the C++ header files referred to in the docs?
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This is a bug in the documentation for 1.6. The #includes listed in the API are not needed for calling some (many?) constructors.
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I'm a Python developer with some background in another language such as Ruby.
In both language, dependency is managed by package manager automatically, such as pip or gem. Anyone could install such dependency by calling pip install -r requirements.txt, and it will install the necessary dependency via Python Package Index. Although, there has been an option to build the dependency manually from the source and install into the project, it is not a recommended process, and I have not done it.
I notice that C++ unfortunately have different nature in how dependency is being resolved for some reason. (e.g. different compiler flavor, compiler parameters, platforms, etc...)
At the moment, I am learning C++ using VS2015. and I have been stumbled again and again upon these library dependencies matter. With VS2015, there is a dependency package manager like python, and it is NuGet. However, not every library is available in NuGet, in fact, there are a lot of library developed independent from its IDE.
First I'm trying to use Boost. There is a manual on how to build the project, but I'm not sure what I need. Do I need to build from source? or Perhaps I just need a library that has been readily available?
Same reason for another library that I found. (e.g. QT, yaml-cpp, googletest, etc..)They only have a document how to build, instead of how to install as dependency.
And Ultimately, I will need to use lots of 3rd party library to be more productive. So, here's some of my questions that are very related.
How do C++ developer normally include 3rd party library into their project (the flow of installation 3rd party library)?
Do I have to build from source everytime I want to include? or perhaps you just need the header file which you could just copy and paste into your project directory?
I'm working in team (git), do each of my team need to build the dependency manually? Can it be automate such that the process of including new library is transparent for everyone?
Or perhaps, I don't really understand what specific question do I need
to ask. But why it is so painful to reuse library in C++?
Do I miss some fundamental understanding of C++ environement?
I'm not sure how much relevance it is, but CMake as a build tool that most library uses to build their project. Do I really need to build these library project?
More Questions:
After building some libraries, some of them generate static library .lib or dynamic library .dll to be included into the project. So is it correct to copy these generated library in our project? Should this be committed into the source version control? Some libraries are very large, and we don't want to maintain it. Yet we need the entire team to get the library transparently.
I understand you situation quite well. You cannot see the forest because too many trees are standing in your way...
Let me get one thing clear before I start to address your specific questions:
Generally speaking, dependencies in C++ are not more complicated than in Python.
The command pip install -r requirements.txt will establish an internet connection and download the necessary libraries and files from a repository server to fulfill the requirements. Under the Linux operating system (Ubuntu) the command: sudo apt-get install libboost-all-dev installs all required dependencies for boost. This is possible because there is a whole environment with servers that hold source-code as well as libraries and binaries that work together with the client programs (apt-get) that use it. This is exactly the same thing that the authors of pip have done for microsoft windows. microsoft themselves have never done this at the operating system level. They always left that to the programmer. NuGet is microsofts attempt to make-up for past mistakes.
Having this out of the way, let me address your questions:
It depends on the size of the 3rd party library. Small libraries like pugixml can be included as source in the source tree of your project. Bigger libraries like boost are better included as binary object code (library objects). Not all libraries do have binaries available to download (boost has), so you might be required to build from source. Bear in mind that all binaries are required to be built with exact the same compiler that you use in your project. The general steps to include it in your VS-Project:
Get the distribution files (either build from source or download and install binaries)
Add include paths to your Project:
Project > "projectname" properties > Configuration Properties > C/C++ > General > Additional Include Directories
Add paths to libraries:
Project > "projectname" properties > Configuration Properties > Linker > Input > Additional Dependencies.
No. You normally just use the header file. But it's better to add the path of the library into your project instead of copying the header file, because some projects (boost) have a huge hierarchy of header files.
It is a good idea that each member of your team has the same development environment with the same set of libraries installed. There are tools for this task: Chocolatey builds on top of NuGet and is therefore windows-affine. Vagrant deals with virtual boxes ands thus offers cross-platform development environments.
But more important is a decent source-control-management system. If you don't already use one - start using one Today!. This is the main collaboration-tool. It can really save your neck if you loose a developer machine.
There is another dependency problem: We've only addressed the development dependencies above. There is the problem of deployment dependencies:
your customers will need the libraries (*.dll files) that you have used for the development. You will need to package them as well into your deployment package (Installer). This is another issue which is probably already answered on SO.
Qt: if you start using Qt, I'd suggest that you start using their development environment Qt-Creator. This will automatically handle all dependencies. It will automatically detect the Visual Studio Compiler that you have installed, and use it. The IDE is quite close to Visual Studio.
CMake: No, it is not always required to use CMake to build a library project, some also include Makefiles. Others use CMake to produce Makefiles. "Follow the instructions" is the best advice I can give here.
Update 2015-10-24: paragraph point three reworked
How do C++ developer normally include 3rd party library into their
project (the flow of installation 3rd party library)?
It depends... There are a lot of ways, how to redistribute C++ libraries.
Do I have to build from source everytime I want to include? or perhaps
you just need the header file which you could just copy and paste into
your project directory?
For now, most C++ libraries contains two parts: binaries + header files. But often, there are a lot of problems, if compiler version of library is different with your compiler.
I'm working in team, do each of my team need to build the dependency
manually? Can it be automate such that the process of including new
library is transparent for everyone?
It depents on your team guidelines. You can choose what you want.
Or perhaps, I don't really understand what specific question do I need
to ask. But why it is so painful to reuse library in C++?
Because of some legacy of C. And because C++ is low-level language in compare with python/java/c#. C++ is supported by a lot of different platforms, including embedded. And ofter, it is not possible to install complex runtime on this platforms. So there are no mechanism to transparently link a "modules" in runtime.
Hopefully, there will be a normal support of modules in C++17 standard. And Microsoft will provide a technology preview of modules in C++ in MSVC 2015 update 1.
Do I miss some fundamental understanding of C++ environement?
Yes, I propose you to read about compiling and linking in C/C++. This two things are often come together, but they are different.
First, that you should mind: code in C/C++ is splitted in two parts: declaration (.h files) and implementation (.cpp files). .CPP files are compiled into binaries. .H files just declares an interfaces.
I am currently taking a few different online programming courses, one of which is the Programming Abstractions Stanford course. They have a set of default libraries that are utilized for the class.
You can download that package here:
http://see.stanford.edu/materials/icspacs106b/cs106libs_for_xcode.zip
I am needing assistance with figuring out how to get this package of libraries into Xcode so that I can utilize them with the programs I write. How can I go about doing that so when I create a new project I can create one that has these libraries ready to go, on top of the standard C++ libraries.
Thanks a bunch in advance!
Edit: I did install the .pkg file, but I do not where it installed. How do I utilize the installed library from within Xcode?
Bad luck. From this page:
How to install external library in X-Code 4
You need to install XCode 3.0 in order to use
CS106LibrariesForXcode.pkg library.
XCode 4 have a very different UI and functionality compared to XCode
3. So it would be unwise to study XCode 3 only. But if you're going to study C++ using those tutorials you'd probably want to install XCode 3
and use it.
Old answer [Not applicable]
If the package is a pkg file, you actually needs to install it. Double-click on it, follow the steps.
If you have a warning message,
CS106LibrariesForXcode.pkg” can’t be opened because it is from an
unidentified developer.
then right-click (or ctrl+click) and select open. The warning will then have an open option to allow you to open the package.
Once this is done, just write a new program, and include the headers you need.
I am trying to open an existing C++ open-source library in Xcode to publish it with my own modification/additions. The library is Tesseract-OCR, which does not include a .xcodeproj file.
Since Xcode can function as an IDE, is it possible to open a bunch of files as a single project in Xcode? Is there an easy way to produce an Xcode project?
There are several ways you could do it, depending on the level of IDE integration you want. There's no direct way of importing a Makefile-based project into Xcode. You can create a project that builds via the Makefile, but you wouldn't get many of the benefits of using an IDE, since the editor features such as word completion rely on Xcode being able to parse the files in the project. You will be able to use the debugger though. To do this, create a new project and add a custom target with a script build phase that just calls down to Makefile.
If however the project you're building compiles very easily, ie without requiring a lot of macros to be set up, include paths, etc, then it may be simple to just create an empty project and merely add all source files to it. I've used this method extensively for building boost libraries. If this is a configure && make type project then you will probably have to run the configure step first, and ensure any top level config.h files are included in the project.
If the project has a complex makefile then it is likely to be an involved task to create a useful Xcode project
I realise you asked explicitly for Xcode, but in case you were actually trying to solve the problem of "I have existing C++ code which builds and runs fine from the command line, and I'd like to code and debug it in an IDE, what should I do?" my firm recommendation would be to avoid Xcode and go for Eclipse.
The reason is that as far as I can tell, Xcode has no way of ingesting the command line build environment and effectively requires you to recreate the make process inside Xcode from scratch. Fine for tiny projects, but anything with more than a few source files and it quickly becomes painful. Whereas in Eclipse everything is built around Makefiles. So in my case I got to the "step through code with working code completion" in Eclipse a lot quicker vs. never in Xcode. This of course could be because I'm an Xcode noob, but my 2c.
To create an Xcode project from an existing cmake project, you can run cmake -G Xcode. It produces some folders and files apart from the project file, so it might be better to create a folder for it first. For example:
mkdir -p build/xcode
cd build/xcode
cmake -G Xcode ../..
Xcode is a useable IDE for library creation.
Of course a good first step is to see if the one source code will build on its own with configure scripts that are included.
If not, it becomes a question of how many libraries you need to link in.
There are resources online (or at least there used to be) for using Xcode (or perhaps it's forerunner Product builder) for porting Unix projects to Mac.
Good tutorial at: http://www.macresearch.org/tutorial-introducing-xcode-30-organizer
Another good reference is Darwin Ports.
As for doing this on your own. You can build c++ based libraries in XCode. People do that every day. You can even use one of the Xcode templates to get you started.
However, library dev requires more experience with Xcode then say a simple Cocoa "Hello World" app.
The remaining questions will be assuring that the source code's dependencies are already built into the Mac's SDK. (Don't hold your breath for linking to MFC)
It's a general question... So it's a general answer.
In Xcode8,there is "Xcode->file->add files to...",then choose your files.If you want to add several files at a time,press "Cmd" when you are choosing.
I'm studying (well, trying to) C right now, but I'm limited to working in Windows XP. I've managed to set up and learn how to use Emacs and can compile simple C programs with gcc (from Emacs no less!), but I'm getting to the point where I'd like to install something like SDL to play around with it.
The thing is that the installation instructions for SDL indicate that, on a Win32 environment using MingW, I would need to use MSYS to run ./configure and make/make install to install SDL, like one would do on Linux. I noticed that when I unzipped the SDL-dev package (forgot the exact name, sorry) there were folders there that corresponded to a folder in the MinGW directory (SDL/include -> MinGW/include).
Am I right in saying that all the ./configure and make commands do is move these files from one directory to another? Couldn't I just move those files by hand and spare myself the trouble of installing and configuring MSYS (which, to be honest, confuses me greatly)?
The build process usually works like this: the configure script finds the appropriate settings for the compilation (like which features to enable, the paths to the required libraries, which compiler to use etc.) and creates a Makefile accordingly. make then compiles the source code to binaries. make install copies the created binaries, the headers, and the other files that belong to the library to the appropriate places.
You can't just copy the files from the source archive, because the source archive does not contain the binary files (or any other files that are created during the make step), so all you'd copy would be the headers, which aren't enough to use the library.
In most case, configure and make will discover the compiler/environment of your machine and build the suitable binary, respectively. Therefore, unfortunately, it will not be easy as moving/copying header files to new locations.
However, in some cases, the library can be the "header only" library. Which means you need only header files to use it.
I have no experience with MSYS and SDL. But the basics of configure and make is worth learning (especially if you are going to program any C/C++ in non-Windows environment.)