C++ in Eclipse—What's a toolchain? - c++

In Eclipse, to build/run a C++ project, I needed to make Mac OS X GCC the default toolchain. What is a toolchain, and why did I have to do this?

Eclipse doesn't bring its own C++ compiler, so you have to specify it in preferences. And since compiler, linker and debugger depend more or less upon each other, these have to be specified too. That's what is called a toolchain: the set of tools (compiler, debugger, linker) that you want to use with eclipse.
You have to set up the toolchain because for most platforms there is more than one available.

Toolchains are the required tools to successfully run a code.
A normal IDE support a large variety of toolchains (compiler, debugger, linker, etc) and since they need them to work to run the code you must specify them before.
**Note:**Its nit something eclipse specific but its a general term for IDEs

Related

Compiling a C++ program with all libs it needs

When I compile C++ code that uses openmp libs with visual studio, the program is very portable - because it runs in other machines with Windows without problems.
When I compile the C++ code with Eclipse CDT (oxygen and g++ cygwin) for Windows, in general, I need to install the correct runtime libs in the other machines to be able to run the program. I don't find it practical.
Based on this:
1) What is the right way to compile the code including all libs (g++ and openmp) to run in another Windows system?
2) How can do this in Eclipse CDT for Windows?
The problem is not in compiling, but in distributing. Windows and windows toolchains intend to use dynamic linking. Now, if created software are dependent on particular version of runtime, which includes side-by-side build, they can be run only if exactly that build is installed. Several builds of same library version may exist, they are fetched using side-by-side (SxS) mechanics.
On Linux platform this problem is solved through package manager and dependencies. On Windows you have to create an installer, which would contain or have ability to download proper version of libraries. Also installer may do proper changes to OS settings, and register them , for future rollback.
Note, that runtime libraries have debug variants which cannot be distributed and debug build of software must be run on developer system only.
"Portable" apps that appear here and there and can be run without installation, have special status not to be dependant on SxS run-time library. To my knowledge cygwin and mingw32 allowed to create such, the 64bit project of mingw had problems with that. But they are still dependant on particular versions of system .dll and may break or malfunction in case of mismatch.
Even in that case you still need some .dll, from mingw, cygwin, Qt, whatever you use and what is not a part of OS, to place them where program can reach them. Which can be folder comtaining the executable. Static linking became a gimmick of past for desktops, because of code bloat - dynamic library size easily can be dozens of megabytes.
And last: you don't compile anything with Visual Studio or with Eclipse CDT. Both designed to use various compilers, it's juse environments. You have to specify normal;y, what compiler your IDE uses, not what IDE you use to run ot.

Clang based on platform in CMake

I'm setting up a cross platform build environment. For that reason I've chosen to go for clang, for the, correct me if I'm wrong reasons:
Using the "same" compiler for different platform would potentially reduce the quirks that arise when getting gcc code to work with MSVC
Clang with its MSVC compatible ABI would let me work with the WINAPI as if I were using MSVC.
My question is: How do I get CMake to, based on the platform, find the correct clang to use, that is clang-cl in Windows and clang on *nix platforms ?
Please note that I'll be using Ninja generator for CMake, and the project is Qt based, if that matters.
You (the project author) don't get to choose the compiler, the user that invokes CMake chooses the compiler.
The only thing you can do from within the CMakeLists is abort with an error if you are not happy with the choice that the user made.
There are a couple of ways how the user can specify to CMake which compiler to use. Popular examples include setting the respective environment variables, passing it via -DCMAKE_CXX_COMPILER on the first CMake run (and only on the first run; you cannot change this later without re-configuring from scratch!), or by using a toolchain file.
On Visual Studio, you can also use the -T option to select a build toolchain. This allows you to build with clang from Visual Studio.
You should document in your project's Readme which compiler you expect your users to configure for CMake and maybe give them a small example how to do this via one of the methods above.

Compiler installation which is simple

Is there any compiler for C++ that works under W7 and is easy to install, except VC++?
I never get these scripts and linux emulations to work, and really just want to try another compiler.
The nuwen distribultion of the GCC compiler includes the compiler and all necessary supporting tools and libraries as a single Windows installer. You don't need any Linux emulation in order to use it. A similar, slightly smaller pacakage is TDM's MinGW build. Both of these are on GCC 4.5 (as of Aug-2010).
If you want an IDE, then Code::Blocks also comes as a complete system. This has recently (Jul-2010) been heavily improved, and comes with the GCC 4.4.1 compiler, if you want it. You might also want to look at CodeLite, which is also fairly easy to install.
Mingw is generally easier than cygwin. It doesn't come with a port of every unix tools as cygwin does, but the resulting .exes are native (no need for cygwin.dll)
Cygwin includes the gcc compiler and also provides a Unix look and feel which will be the other thing you need to get scripts and linux emulations to work. (This inlcude the libraries Unix libraries will have functions that VC does not have which might be the issue that you are having)
Qt for Windows comes with MingW, which I've found to be reasonably easy to use and install, and the LGPL version is priced right (free as in beer). You don't need to use any the Qt libraries in your application. I'm not sure which version of GCC is currenlty bundled with it. There are no licensing restrictions for the software you develop (unless you're actually modifying and redistributing source code of the LGPL version of Qt).

Do I really need Visual Studio

Do I really need Visual studio to build c/C++ application on Windows.
Is there any way to have makefiles and get the application built.
You can use any compiler that'll target Windows (for example, MinGW, Digital Mars, Comeau or others). All of them can be driven by the command line so you can use your preferred make utility (or other build utility).
That said, Visual Studio is pretty nice (even the free version). And don't forget that it installs the command line compiler tools, so you can drive it from a makefile as well (unfortunately, it won't spit out a makefile for you anymore, but it has it's own command line tools to drive a build based on project settings if you want to jump from IDE to command line builds).
If you want to stick to the Microsoft toolchain but don't want the IDE, you can use cl and link to build from the command line in conjuction with either the MSBUILD system or NMAKE.
If you don't have the compiler it is available free with VC++ Express.
To install the Microsoft compiler without installing an IDE download the Windows SDK which is available for free.
http://en.wikipedia.org/wiki/Windows_SDK
Qt is very nice, and downloading and installing the SDK gets you the QtCreator which provides a consistent IDE across platforms, with very nice builtin help, build system, access to revision control, debugging, ... and it even includes the MinGW compiler and toolchain for you.
MinGW is something simpler: the usual GNU toolchain but setup such that it provides native Windows binary.
Last but not least, there is Cygwin which gives you the most Unixy flavour.
No, you don't.
I know you said c, but you can also check out MonoDevelop, should you choose to do more than just that: http://monodevelop.com/Download
No you do not. There are many free IDE's out there, or you can do everything from the command line with a non-microsoft compiler.
www.bloodshed.net offers a pretty good IDE that uses the Mingw compiler.
You can even do without extra tools as long as you have the compilers on your machine. Take a look here for an explainatin:
http://msdn.microsoft.com/en-us/library/ms235639.aspx
Not at all. It is quite possible to do Win32 programing, including OS and GUI programming, with gcc from Mingw.
For all my hobby work, if I can I use the gcc compiler from Mingw (for C or Ada), with Emacs as my IDE and gnumake for my build system. There are good Mingw ports for all the major revision control systems too, including Git.
That's the toolset I used to create the SETI#Home Service, which was a wrapper for the SETI#Home client that installed and ran it as a Windows service, did failure detection and auto restarts, and had a built in web server for monitoring. All that with no VisualStudio.
You can use Eclipse with C/C++ Development Toolkit and with Mingw Compilers. the only problem is that you will not have M$ Stuff like MFC, but you can use QT or wxWindows
Two solutions that immediately come to mind:
Cygwin
MinGW
Using makefiles does not prevent you from using the Microsoft C++ compiler, which is nice if you want to use the VS debugger.

Best way to setup a Windows build environment for C/C++

Basically I want to compile C/C++ using the GCC on Windows. The two competing platforms, as i see it, are MinGW and Cygwin. Each have their own benifits and limitations. MinGW compiles for Windows, whereas Cygwin needs the cygwin .dll. However installing libraries on MinGW is difficult, whereas on cygwin it's easier, using the setup.exe as a 'package manager'.
My question is what's the best way to compile on Windows. Would it be better to use MinGW and struggle with libraries (in which case is there an easy way of installing libraries on MinGW). Or should I use Cygwin, if so how do I get it to compile without needing the cygwin .dll, effectively compile for normal Windows.
The easiest and best way to compile on windows is to use visual studio express. It is free. A good reason for using cygwin is for cross platform builds. A good reason to use gcc is it supports some compiler candy the Microsoft compiler doesn't.
But all in all VC++ Express is the way to go for windows only development.
There is always the option of using -mno-cygwin with Cygwin to compile against Windows libraries like MinGW does:
gcc -mno-cygwin file.c -o test
It's not an easy choice and mainly depends on how much you will rely on other libraries. Cygwin really adds an additional layer, which is heavier but "emulates" the Linux environment better than MinGW.
Edit:
Qt Creator allows you to compile with MinGW on Windows (and gcc on Linux, ...), has an IDE that makes debugging more friendly than gdb. If you need libraries, you still have the option of using the Qt libraries. That would be a good alternate solution to the Visual Studio if you really want to stick to gcc for future portability.
You might want to look at CodeBlocks. It is generally used to build WxWidgets apps, but it wraps MinGW nicely.
Actually, there's option #3: if your edition of Windows permits it, you can install Microsoft Services For Unix / Subsystem for Unix Applications, and then get gcc from SUACommunity. It has a package manager, too. Of those 3 options, this will give you behavior closest to a true Unix system.
However, the resulting applications aren't Win32 applications; they're SUA applications, and will require SUA to run. If you write code for yourself, it's usually not a problem if you write code for yourself, but if you want to write and distribute a proper Windows application, I would suggest staying away from anything that tries to emulate Unix, so MinGW it is.
Qt Creator comes with MinGW as standard and can be used to build projects that don't actually use the Qt framework.
There's an easy to install MinGW wrapped GCC at equation.com.
Click "Programming Tools" then "Fortran, C, C++", download the release you prefer, install and use.
One possible method is to use CMake which can build Visual Studio project from your sources and then compile from Visual Studio. It can build project for other IDEs too, so you can go cross platform.
I think the answer depends on whether you intend to use libraries or compile programs that are targeted to POSIX or a POSIX-based target. That's what Cygwin is intended for, while MinGW is more intended for compiling Windows-targeted programs using GCC.
Another option is TDM MinGW: http://www.tdragon.net/recentgcc/
It's basically an unofficial fork of MinGW with the latest GCC compiler available for both 32- and 64bit windows machines. Even some MinGW developers themselves use it.
Equation Gcc is even better: http://www.equation.com/servlet/equation.cmd?fa=fortran