What is MakeFile in Eclipse? - c++

What is MakeFile in Eclipse? From the documentation:
A makefile is a text file that is referenced by the make command that
describes the building of targets, and contains information such as
source-level dependencies and build-order dependencies. The CDT can
generate a makefile for you, such projects are called Managed Make
projects. Some projects, known as Standard Make projects, allow you to
define your own makefile.
But the explanation does not help me understand what a MakeFile is. I am moving from VisualStudio/C# to Eclipse/C++. Is MakeFile analogous to Visual Studio's Metadata? When do I need to write a MakeFile, and why do I need it besides the C++ code?
[EDIT]
I used to develop on Windows with VS and C#. And now trying Eclipse/C++ on a Mac. I have never build anyone on Linux. So the answer I have read so far does not help explain anything at all.

A makefile in the simplest terms is a file that builds a program. These are normally used from the command line. If you have ever built something on linux you may have run ./configure ; make ; make install. You are using a makefile there.
More info...
https://en.wikipedia.org/wiki/Make_(software)

In simple terms: Make helps you create cross-platform configuration settings in one file, and it will work on surprisingly many platforms, including Windows or Mac OS-es.
Mentioning Windows, you should have Make installed on the computer you're installing on (on Windows, Cygwin and MinGW include Make). It's required only if the user will actually build the code from the source.
But of course, you should include Make code for each different platform (e.g. one for Unix-like, one for Windows, etc.)

Related

Getting a library to work (QuadProg++ )

I'm trying to use the Quadprog++ library (http://quadprog.sourceforge.net/). I don't understand the instructions though.
To build the library simply go through the ./configure; make; make
install cycle.
In order to use it, you will be required to include in your code file
the "Array.hh" header, which contains a handy C++ implementation of
Vector and Matrices.
There are some "configure", and "MakeFile" files, but they have no extension and I have no idea what to do with them. There are also some ".am", ".in" and ".ac" extensions in the folder.
Does this look familiar to anyone? What do I do with this?
(Edit: On Windows.)
This package is built using the autotools. These files you talk to (*.am, *.in...) are because of the tools automake, and autoconf.
Autotools is a de-facto standard in the GNU/Linux world. Not everybody uses it, but if they do you ease the work of package and distribution managers. Actually they should be portable to any POSIX system.
That said, I'm guessing that you are using a non-unix machine, such as Windows, so the configure script is not directly runable in your system. If you insist in keep using Windows, wich you probably will, your options are:
Use MinGW and MSYS to get a minimal build enviroment compatible with autotools.
Use Cygwin and create a POSIX like environment in your Windows.
Create a VS project, add all the source of the library in there, compile and debug the errors they may arise, as if the code had been written by you.
Search for someone that already did the work and distributes a binary DLL, or similar.
(My favourite!) Get a Linux machine, install a cross-compiler environment to build Windows binaries, and do configure --host i686-mingw32 ; make.
This instruction say how can be build an program delivered like a tarball in Linux. To understand take a look on Why always ./configure; make; make install; as 3 separate steps?.
This can be confusing at first, but here you go. Type these in as shown below:
cd <the_directory_with_the_configure_file>
./configure
At this point, a bunch of stuff will roll past on the screen. This is Autoconf running (for more details, see http://www.edwardrosten.com/code/autoconf/index.html)
When it's done, type:
make
This initiates the build process. (To learn more about GNU make, check out Comprehensive gnu make / gcc tutorial). This will cause several build messages to be printed out.
When this is done, type:
sudo make install
You will be asked for the root password. If this is not your own machine (or you do not have superuser access), then contact the person who administers this computer.
If this is your computer, type in the root password and the library should install in /usr/local/lib/ or something similar (watch the screen closely to see where it puts the .so file).
The rest of it (include the .hh file) seems self-explanatory.
Hope that helps!

C++ IDE that autogenerates cmakelists.txt

I'm looking for an IDE that automatically generates a cmake file from the project. Ideally I would like the project to be independent of the IDE. I am mainly working under linux but Windows is a major (and great) OS so ideally it would run on Windows as well. I'm not too bothered about that though as on Windows there is VS :).
Regards
EDIT: Yeah, I sort of see my mistake. I should have asked for an IDE that generates makefiles instead of cmake files since the cmake layer/step becomes useless (if the IDE can directly generate a makefile).
The purpose of CMake is to generate the Makefiles and projects that other development environments rely on, so what you're asking seems a little backwards. CMake is exactly the tool that does what you're asking to do, but in a different direction.
That said, KDevelop 4 has the option to use CMakeLists.txt files instead of the usual project file, but it doesn't work very well, and I've given up on trying to use it. Instead I edit the CMakeLists.txt file by hand - and KDevelop helpfully updates the GUI appropriately to reflect my changes.

how to compile a VC project using g++?

i have source code of vc++ project. Now I am using linux.
i know how compile a single file .cpp not a whole project. So how to compile a VC project using g++ ?
A slight advantage of Makefiles would be possible integration with autotools (cough - It might prove handy to get the starting point for feature macros).[2]
There is a tool as part of winemaker that is EXCEEDINGLY helpful with fixing up a source tree that was assuming case insensitive names to work on a case-sensitive filesystem. (_it was intended mainly in order to build against winelib but that is not required)
If you want to keep using windows API's for some parts of the code, you can consider compiling with winelib (and use winegcc, producing WIN32 executables; I'm not sure whether this is what you want)
[2]: SCons is a very nice tool though
First step would be to generate Makefile out of vcproj file.
There are (obviously) some tools for that:
http://www.codeproject.com/KB/cross-platform/sln2mak.aspx
There is no easy way to do it. As others have suggested you can figure out how the build process works for this project (maybe by reading the build output in VS) and recreate that using your favorite linux build tool (scons, cmake, autotools etc.). The alternative is to use a converter tool. Aside from the below mentioned sln2mak, there is also winemaker. The docs for winemaker have a lot of old info like most linux tools docs but it can convert a .sln to a makefile. I am not sure about newer vs .sln files.

Import existing C++ project into Xcode IDE

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.

C++ Buildsystem with ability to compile dependencies beforehand

I'm in the middle of setting up an build environment for a c++ game project. Our main requirement is the ability to build not just our game code, but also its dependencies (Ogre3D, Cegui, boost, etc.). Furthermore we would like to be able build on Linux as well as on Windows as our development team consists of members using different operating systems.
Ogre3D uses CMake as its build tool. This is why we based our project on CMake too so far. We can compile perfectly fine once all dependencies are set up manually on each team members system as CMake is able to find the libraries.
The Question is if there is an feasible way to get the dependencies set up automatically. As a Java developer I know of Maven, but what tools do exist in the world of c++?
Update: Thanks for the nice answers and links. Over the next few days I will be trying out some of the tools to see what meets our requirements, starting with CMake. I've indeed had my share with autotools so far and as much as I like the documentation (the autobook is a very good read), I fear autotools are not meant to be used on Windows natively.
Some of you suggested to let some IDE handle the dependency management. We consist of individuals using all possible technologies to code from pure Vim to fully blown Eclipse CDT or Visual Studio. This is where CMake allows use some flexibility with its ability to generate native project files.
In the latest CMake 2.8 version there is the new ExternalProject module.
This allows to download/checkout code, configure and build it as part of your main build tree.
It should also allow to set dependencies.
At my work (medical image processing group) we use CMake to build all our own libraries and applications. We have an in-house tool to track all the dependencies between projects (defined in a XML database). Most of the third party libraries (like Boost, Qt, VTK, ITK etc..) are build once for each system we support (MSWin32, MSWin64, Linux32 etc..) and are commited as zip-files in the version control system. CMake will then extract and configure the correct zip file depending on which system the developer is working on.
I have been using GNU Autotools (Autoconf, Automake, Libtool) for the past couple of months in several projects that I have been involved in and I think it works beautifully. Truth be told it does take a little bit to get used to the syntax, but I have used it successfully on a project that requires the distribution of python scripts, C libraries, and a C++ application. I'll give you some links that helped me out when I first asked a similar question on here.
The GNU Autotools Page provides the best documentation on the system as a whole but it is quite verbose.
Wikipedia has a page which explains how everything works. Autoconf configures the project based upon the platform that you are about to compile on, Automake builds the Makefiles for your project, and Libtool handles libraries.
A Makefile.am example and a configure.ac example should help you get started.
Some more links:
http://www.lrde.epita.fr/~adl/autotools.html
http://www.developingprogrammers.com/index.php/2006/01/05/autotools-tutorial/
http://sources.redhat.com/autobook/
One thing that I am not certain on is any type of Windows wrapper for GNU Autotools. I know you are able to use it inside of Cygwin, but as for actually distributing files and dependencies on Windows platforms you are probably better off using a Windows MSI installer (or something that can package your project inside of Visual Studio).
If you want to distribute dependencies you can set them up under a different subdirectory, for example, libzip, with a specific Makefile.am entry which will build that library. When you perform a make install the library will be installed to the lib folder that the configure script determined it should use.
Good luck!
There are several interesting make replacements that automatically track implicit dependencies (from header files), are cross-platform and can cope with generated files (e.g. shader definitions). Two examples I used to work with are SCons and Jam/BJam.
I don't know of a cross-platform way of getting *make to automatically track dependencies.
The best you can do is use some script that scans source files (or has C++ compiler do that) and finds #includes (conditional compilation makes this tricky) and generates part of makefile.
But you'd need to call this script whenever something might have changed.
The Question is if there is an feasible way to get the dependencies set up automatically.
What do you mean set up?
As you said, CMake will compile everything once the dependencies are on the machines. Are you just looking for a way to package up the dependency source? Once all the source is there, CMake and a build tool (gcc, nmake, MSVS, etc.) is all you need.
Edit: Side note, CMake has the file command which can be used to download files if they are needed: file(DOWNLOAD url file [TIMEOUT timeout] [STATUS status] [LOG log])
Edit 2: CPack is another tool by the CMake guys that can be used to package up files and such for distribution on various platforms. It can create NSIS for Windows and .deb or .tgz files for *nix.
At my place of work (we build embedded systems for power protection) we used CMake to solve the problem. Our setup allows cmake to be run from various locations.
/
CMakeLists.txt "install precompiled dependencies and build project"
project/
CMakeLists.txt "build the project managing dependencies of subsystems"
subsystem1/
CMakeLists.txt "build subsystem 1 assume dependecies are already met"
subsystem2/
CMakeLists.txt "build subsystem 2 assume dependecies are already met"
The trick is to make sure that each CMakeLists.txt file can be called in isolation but that the top level file can still build everything correctly. Technically we don't need the sub CMakeLists.txt files but it makes the developers happy. It would be an absolute pain if we all had to edit one monolithic build file at the root of the project.
I did not set up the system (I helped but it is not my baby). The author said that the boost cmake build system had some really good stuff in it, that help him get the whole thing building smoothly.
On many *nix systems, some kind of package manager or build system is used for this. The most common one for source stuff is GNU Autotools, which I've heard is a source of extreme grief. However, with a few scripts and an online depository for your deps you can set up something similar like so:
In your project Makefile, create a target (optionally with subtargets) that covers your dependencies.
Within the target for each dependency, first check to see if the dep source is in the project (on *nix you can use touch for this, but you could be more thorough)
If the dep is not there, you can use curl, etc to download the dep
In all cases, have the dep targets make a recursive make call (make; make install; make clean; etc) to the Makefile (or other configure script/build file) of the dependency. If the dep is already built and installed, make will return fairly promptly.
There are going to be lots of corner cases that will cause this to break though, depending on the installers for each dep (perhaps the installer is interactive?), but this approach should cover the general idea.
Right now I'm working on a tool able to automatically install all dependencies of a C/C++ app with exact version requirement :
compiler
libs
tools (cmake, autotools)
Right now it works, for my app. (Installing UnitTest++, Boost, Wt, sqlite, cmake all in correct order)
The tool, named «C++ Version Manager» (inspired by the excellent ruby version manager), is coded in bash and hosted on github : https://github.com/Offirmo/cvm
Any advices and suggestions are welcomed.