I am creating a open-source C++ library using Visual Studio 2005. I would like to provide prebuilt libs along with the source code. Are these libs, built with VS2005, also going to work with newer versions of Visual Studio (esp VS Express Edition 2008)? Or do I need to provide separate libs per VS version?
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224answers:
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A:
If you are distributing static libraries, you may be able to distribute version-independent libraries, depending on exactly what you are doing. If you are only making calls to the OS, then you may be OK. C RTL functions, maybe. But if you use any C++ Standard Library functions, classes, or templates, then probably not.
If distributing DLLs, you will need separate libraries for each VS version. Sometimes you even need separate libraries for various service-pack levels. And as mentioned by VolkerK, users of your library will have to use compatible compiler and linker settings.
Due to these issues, instead of spending time trying to build all these libraries for your users, I'd spend the time making it as easy to build as possible, so that users can can build them on their own with minimal fuss.
Kristopher Johnson
2009-10-21 12:09:44
And even project settings/compiler flags can cause binary incompatible code within the same compiler version, e.g. /Zc:wchar_t (which being on by default was a breaking change in VS2005)
VolkerK
2009-10-21 12:19:29
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A:
Not normally, no. Libraries built with the VS tools are linked into the 'Microsoft C Runtime' (called MSVCRT followed by a version number) which provides C and C++ standard library functions, and if you attempt to run a program that requires two different versions of this runtime then errors will occur.
On top of this, different compiler versions churn out different compiled code and the code from one compiler version frequently isn't compatible with another apart from in the most trivial cases (and if they churned out the same code then there would be no point having different versions :))
workmad3
2009-10-21 12:13:15
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A:
Generally it's not possible to link against libraries built with different compilers, different versions of the same compiler, and even different settings of the same compiler version and get a working application. (Although it might work for specific subsets of the language and std library.) There is no standard binary interface for C++ - not even one for some common platform as there are in C.
To achieve that, you either need to wrap your library in a C API or you will have to ship a binary for every compiler, compiler version, and compiler setting you want to support.
sbi
2009-10-21 12:21:32
GCC defines an standard ABI that all version of GCC use. Intel's compiler uses the same ABI so libraries compiled by intel can be used by gcc. However, MSVCRT and glibc need to be same between the library and the application as mentioned by workmad3.
caspin
2009-10-21 16:47:03
@Caspin: Yes, but even this fails if not both sides of that ABI use exactly the same version of the std lib and every other library whose types they want to pass across the boundary. That's a ticket to myriads of very hard to debug errors that might only show up under certain, very rare circumstances. BTDT.
sbi
2009-10-21 17:03:58