I want to learn C++ and I want to know if using Microsoft VC++ will tie me to Windows. I specially need my project to also run on Mac. My projects are all Class libraries and have no dependency to UI. They are just calculations or file/network IO.
I really like working in Visual Studio and Microsoft way overall. So my priority is to go VC++ unless it makes painful to build cross platform apps for Windows and Mac. I mean at the compiler, libraries and language level. I don't want my parallel app to fall apart on certain platforms.
I personnaly use Visual Studio to build my code on Windows and other compilers to build the same code on other platforms (Mac, Linux, Android...).
To be sure you don't get locked with Windows, make sure (at least, it's not exhaustive):
You don't use any win32 API (prefer cross plateforme libraries like boost for instance for network, file system access...)
You don't use 3rd party libraries only available for Windows
Don't use CString, or anyother Microsoft class. Prefer STL.
Be careful with file system case sensitiveness too! (#include "Foo.h" while file is "foo.h" on disk will work on PC, not under Mac/Linux). Prefer naming ALL your files in lower case.
...
You may want to have a look at CMake. This tool can help you generating compilation project file for the same source to be compiled on different plateform. Then, you can generate vcproj/sln files to compile your code with Visual Studio on Windows, MakeFile(s) to compile it under Linux and XCode project files to compile it under MacOS. If somewone wants to compile you code under Windows with another compiler than Microsoft, it's also possible!
Also note that recent version of VS (2015) propose to compile for other targets that Windows (at least Android). But never tried that.
The compiler itself is pretty standard confroming by know (if you turn off the extensions) and more importantly, you can use the clang frontend (which is the default compiler on Mac) directly from within VS2015, so it is definitvely possible to write cross-platform code in VS (although it's certainly easier to use Windows specific constructs than it where if you'd use e.g. cygwin).
However, the windows API for network I/O is different from the one for Mac, so you should probably use a corssplatform library like boost asio for that.
As far as multithreading is concerned, you can do it in a standard and portable manner using the standard library's functions, classes and synchronization primitives, but the past has shown that they are often not the most efficient way to go. However, in most situations you'll want to use a more highlevel library for parallel programming anyway. The default on Windows is the PPL which is - I believe - not cross-platform, but there are other libraries you can use
Finally, you can use VS to remotely build your applications on Mac or Linux PCs using their local compilers and libraries. However, I don'T know, how well that works in practice.
Related
Some open source projects explicitly state that in order to compile on windows, they need a microsoft compiler (often a specific version as well, as latter versions are incompatible or will refuse to compile older code).
Since it seems absurd to me that, since there are foss compilers that can compile for windows, a microsoft compiler would be necessary for any fundamental task, I'm assuming this is because those projects use api calls to libraries (such as msvcrt*.dll) that, for some reason, mingw-gcc, clang and other ports of compilers for windows are unable to compile against.
My understanding of these requirements is shallow, since my experience with compiled code comes primarily from linux and this worries me, since getting a microsoft compiler is non-trivial. the only way to get them is through the express editions of microsoft's visual c++, and even then, the most recent version will completely refuse to install on an old winxp machine like mine and the only version available at the moment is vc++express2010, which requires registrations to turn from trialware into freeware (and even then i'm not clear on if that'll work or what it entails - perhaps OS hooks to "debug" and other intereference?).
1) My question is, do these projects depend on microsoft compilers due to building against these microsoft-only libraries (which apparently foss compilers can't do)?
It would seem absurd if the reason is the build script or preprocessor directives, since those can be relatively easily ported.
2) Also, is it possible that, even if I avoid any msvcrt/.net/etc. calls, i can still find myself needing a microsoft compiler to compile native windows software (assuming no usage of libraries that do perform those calls)?
3) Can I simply use clang and some widget library to make native windows software just as well?
4) Can I modify the source of a project so that it doesn't depend on a microsoft compiler?
(ok that's 4 questions, sorry, this is quite hard for me to express clearly).
1) My question is, do these projects depend on microsoft compilers due
to building against these microsoft-only libraries (which apparently
foss compilers can't do)?
Compiler vendors and GUI framework vendors can supply DLLs that perform similar to the MS DLLs. Some of the MS DLLs are system DLLs and are used by the other compiler and framework vendors.
If you are using compiler or framework specific DLLs, they need to accompany the installation of your programs (projects).
2) Also, is it possible that, even if I avoid any msvcrt/.net/etc.
calls, i can still find myself needing a microsoft compiler to compile
native windows software (assuming no usage of libraries that do
perform those calls)?
No. If you scan through the posts on StackOverflow, there are many people who are using the Windows API directly, I guess what you are calling native windows software. Usually, the code for these API are located in a system API. The compiler translates the function call to a call into these DLLs, loading them as necessary.
3) Can I simply use clang and some widget library to make native
windows software just as well?
No, you can't. That's why they exist.
Again, many people are using frameworks like Qt and xWidgets without the MS compilers. I did that for a while. I switched over to Visual Studio, primarily for the debugger. I didn't like how other IDEs tried to use GDB. Otherwise, I wouldn't use MS because they tend to go by the Microsoft Standard language rather than the ISO.
4) Can I modify the source of a project so that it doesn't depend on a
microsoft compiler?
No, that is why there are freeware and other compilers out there.
Hmmm, one can use Java to create GUIs that don't use the MS compiler, but they use the Windows API.
Try installing Cygwin. When you look at all the libraries you will realize that projects can be created that don't use the MS Compiler. Again, read through the StackOverflow posts and you will find that people are using other compilers, such as Intel, GNU, Clang, Greenhills and others. Some compilers for embedded systems will also compile for Windows OS, so you can write code that works on both platforms.
Looks like you need to search the web for "GNU GUI tutorial C++" and see what pops up. Also, search for "wxWidgets" and "Qt" for other frameworks.
I've got new task to research the way of development C++ cross platform (Mac/Win) utility for our internal needs.
I've developed for 7 years using different "pink" languages like C# , Java , Managed C++.
But in this task , the requirement is to support Mac , and .NET that is running on Mac , is really pain (Know this from other guys who did used this).
So I've started to think about C++ if it's possible to use C++ for Cross platform development.
The application will no contain any GUI , but will contain a lot of System API calls , and a lot of business logic analysis.
Is there possible some library allowing to achieve such kind of Task ?
Is it possible to do at all ?
Yes, you can write standard, ISO C++ and run the programs on both platforms.
When you need to implement some functionality using platform specific APIs (e.g. using Win32 on Windows and POSIX APIs on Mac OS) then what you do is write your own wrapper functions that abstract away the platform specific details, and then use that wrapper in the rest of your program.
Tools like CMake will allow you use Visual Studio to build the program on Windows and Xcode to build on the Mac without having to manually manage separate Visual Studio and Xcode project files.
If I understand your question properly, the only thing you need to develop cross platform c++ is to get the right compilers. You could use GCC on both platforms or even use 2 different project files for visual studio and xcode. That's up to you. Personally, I prefer GCC.
Regarding code itself, it depends on what you do with it. STD is available on both platforms (std::vector, std::string, etc) so code should compile properly on both platforms.
Edit: Btw, most platform specific stuff are available through open source code (like boost though I personally don't like boost that much). If needed, you could even look at other open source projects that are cross platform (ogre3d, etc).
I have a C++ eclipse project that I would like to easily compile In Windows and OSX.
The project is currently using an automatically generated makefile.
The libraries that I need vary depending on the platform.
In osx I'm using the CoreMidi, CoreAudio, and CoreFoundation frameworks.
In Windows I'm using the winmm.lib and multithreaded libraries.
What's the simplest way to link different libraries/frameworks depending on the current platform?
I'm currently using the gcc toolchain on OSX. Should I start using the cross compile toolchain?
Should I have two projects. One for working in windows, and one for osx, checking them both in to version control?
Should I write a custom makefile instead of using the automatically generated option that has different g++ arguments depending on the platform?
I personally had the same goal for a project and came to the conclusion the Qt framework was the best thing for me. It handles multiple languages, unicode strings, XML, network communications, native looking user interfaces, console applications: it can do an AWFUL lot.
However, as Paul pointed out, you really have to plan it from the start.
Qt does a good job of abstracting the platform away (in a module called QtCore) allowing you to write vanilla C++ code, or you can chose to include some Qt C++ language extensions which a Qt helper application called the moc (meta object compiler) creates vanilla C++ from, which can then be compiled by most common C++ compilers.
It also has a nifty cross-platform makefile generator called qmake which works on project files to create normal make files for the platform its running on.
Off the top of my head at least Windows XP & 7, OSX 10.4, 10.5, 10.6 are supported currently. But note that OSX Lion is (as of writing) not officially supported but I suspect it will be in the next release.
Based on your description, I am not sure you can easily make it cross-platform. Even without using third-party library, you have to provide separate code for osx and windows. Most of time, they design the system as cross-platform first. It's really hard to make an existing project on single-platform to cross-one. If you have the cross-platform requirement, you'd better design in that way first and rewrite from scratch.
Even though Eclipse can run fine on both OS X and Windows, it is not designed to be used in this way.
The best way to do it is to use separate IDE projects for each platform. This this is the easiest way to have unique compilation settings for multiple platforms.
Yes, you can use two eclipse projects. Alternatively, it's not unusual to have a X-Code project for OSX, and a Visual Studio Project for MS Windows.
How could I write a program which runs on both Windows 7, Mac OS X (and maybe linux too)?
I heard Qt are a great framework to build cross-platform GUIs, but I think every program version need a recompile, isn't that right? And should I compile the win version under windows, the mac version under mac os x, the linux version under linux and so on?
I'm getting ideas and/or suggestions
The underlying binary format is different on each platform, so unless you're using a virtual machine (like Java or Flash does) you will have to recompile your program on each platform.
Some compilers (like GCC) allow cross-compiling, but it is not trivial to set up. Probably the easiest system to cross-compile on is Linux (there are several open source projects that have cross compilation set up from Linux to Windows).
In case of a GUI application, it depends on the language -- if you're stuck with C++, Qt or wxWindows might be a reasonable choice providing an abstraction layer over the native windowing system.
If you can go with Java, it makes life simpler, however the windowing system is Java's and not native.
Another language to think about is FreePascal w/ Lazarus -- it has a pretty good GUI designer that compiles to the native windowing system on every platform (WinAPI on Windows, Cocoa on OSX and GTK on Linux).
Not sure if C++ is a must, but Adobe Air is a great cross platform development environment for desktop, and its growing for mobile development as well. If you need an example of a major application using Adobe Air to deploy to multiple desktop OSes, just check out tweetdeck http://www.tweetdeck.com/
I'd highly suggest also looking into Flex and Flash Builder if you go that route.
There are two separate issues I would highlight when writing cross-platform programs -- how to make your code portable, and how to arrange for it to be built on the various different platforms.
As far as the building side of things goes, I would look into a cross-platform build system like CMake (http://www.cmake.org). You essentially write a script and CMake will generate the appropriate project file/makefile for a specific platform. You then build your program on each platform as you would normally. For example, on Windows, you might use CMake to generate a Visual C++ project for you, and then use Visual C++ to actually build your executable. On Linux, you might use CMake to generate a makefile, and then build the executable using g++.
The other aspect is how to make your code portable -- the key is to write C++ standard-compliant code and make use of libraries that are themselves portable across the platforms you're interested in. You can (and may sometimes need to) write platform-specific code for each of the different platforms -- if you do, you should hide it behind a portable interface and have the rest of the code use that.
Yes, you need to compile for each version when using C++.
The only thing that prevents you from compiling a program, for example, for Windows on Mac is to get a tool for doing that. It is possible, but the problem is finding the toolset.
Also you can use a virtual machine for running diferent OSs and compiling code for all platforms on the same machine.
Java runs on Windows, OS X and Linux
What's in MS Visual C++ runtime library? I mean, I googled it, and I always found things like help, app xxxx gives me MS Visual C++ runtime library error, with no explanation.
I thought that Windows C runtime libraries come with Windows? Not with VC++? Thanks.
EDIT:
First, thanks for answers. I thing now I have bad idea of runtime libraries in windows. I mean, the first part, that Windows internally has its win32 API and so, that's OK, I knew it. Also, that Win32API are from kernel and user parts.
But I always thought that functions like GDI are accessed as DLL (which I still believe they are). But I thought even functions like printf and so are in some windows file.
So, am I right, when I know get it that "simple" functions like printf need to be linked directly and than use only Kernel part of OS directly, and more sophisticated Windows API functions are linked as dlls, therefore ARE NOT distributed with compiler but with OS? And they subsequently access Kernel?
I mean, lets say GDI, I tell it to draw picture, it makes all the hard work in user mode and than call kernel function which puts it all in framebuffer?
And last thought, why is this even solved this way? I mean, if VC++ runtime is just layer between C and WinAPI, why cant VC++ call directly WinAPI?
This is an oversimplification, but it will give you the gist. The MSVCRT is a set of DLLs that implements parts of the C++ language. Functions like printf, memcpy and the like are implemented in these DLLs.
Every program that is compiled with a particular compiler and dynamically linked to the C++ runtimes must somehow have the correct version of the CRT binaries on the target machine. As a result, applications that ship to end users are often (usually?) also shipped with a package of these DLLs. This package is called a "redistributable" (or "redist"), and there is a different one for every combination of exact compiler version and target platform. For example, there are seperate and distinct redists for each of the following:
MSVC 10, 64-bit windows
MSVC 10, 32-bit windows
MSVC9, 64-bit windows
MSVC9 SP1, 64-bit windows
et cetera.
Yes, Windows usually "comes with" some version of the CRT. However, it comes with the version(s) that it needs in order to run the apps that shipped with Windows. If Windows and all it's apps were compiled in MSVC8 SP2 and your app is compiled in MSVC10, the CRT you require won't be present on the box simply because it's running Windows.
This is why its common practice to ship apps along with redists.
EDIT:
By way of Houdini like magic, I predict your next question will be "where do I get the redists?"
The answer is, from MicroSoft. Try a google search for "msvc 9 x64 redist" and you will find:
http://www.microsoft.com/downloads/en/details.aspx?familyid=bd2a6171-e2d6-4230-b809-9a8d7548c1b6&displaylang=en
A brief answer would be that the MSVS C/C++ runtime implements functions like malloc/free, stdio, iostream and some c++-stuff like dynamic_cast and exception handling. These differs between versions of visual studio, so there are different runtimes for different versions.
Windows ship mostly with a C API (the Win32 API) which rather different from the C/C++ standard library. The MSVS C/C++ runtime calls into this API to allocate memory, etc etc.
(I suppose some of the applications included with Windows are written with MSVS and in C++, so they do include the MSVS runtime for that version.)
Also, the runtime changes as new Visual Studio versions are released. A Windows release lasts much longer than that.
They are the libraries that implement the C and C++ standard library functions. Standard functions such as printf are implemented in these libraries.
The core Windows libraries only provide interfaces to system calls, i.e. the Win32 API, since that is all you need to build a full-featured Windows application. The VC++ libraries are mostly wrappers around this API, and are analogous to the glibc library on Linux.
As an example, malloc from the C library might in turn use the VirtualAlloc API to allocate memory.
Programs compiled with Visual C++ require a "runtime" - this is a bit of code that handles application startup/shutdown, memory allocation/deallocation, support for reading and writing files, etc.
This is not part of the operating system, and not part of the final application - Because all C++ applications can share it, by default the runtime is a separate installation.
In addition, each version of Visual C++ has its own runtime installer, because with each version there are slight differences and improvements in the way all this works. There are also different verisons of the runtime for different platforms (e.g. x86 and x64)
Hence, there are a number of "Visual Studio XXXX runtime installer (YYY)" downloads available from Microsoft, where the XXXX is the visual studio version (2005, 2008, 2010, etc), and YYY is usually "x86" or "x64".
Most applications that need the runtime will automatically install it if needed, so generally end-users are not very aware of these redistributables.