I got a project that uses Cmake and has a configuration to create a shared library. This project has some external dependencies (like zlib, etc). Generating shared library and linking against it would require not only providing dll generated by the project, but also dlls for all dependancies (since the library itself is linked against other libraries).
I'm wondering if it's possible to create a single dll of that project, that would have statically linked all dependencies into it. I tried creating an OBJECT library and using it to create a SHARED library with Cmake, but had no luck with this approach. Is this can be achieved?
Unfortunately static linking of the whole library is not an option due to licensing issues and I'd like to avoid attaching 10 dlls to the application package. I need that only for Windows.
Related
I have some XML parsing utility functions written inside C headers and source files based on expat library.
For this I have compiled my source files to a static library with expat statically linked to it.
I am able to use and the functions from the resulting xml utilities library with my applications only if I statically link both the utility library and expat with my application. I was of the view that I should be able to get my application built with only statically linking my utility library without requiring to statically link expat again with the application executable. Only linking my application with the utility library gives undefined symbol error for expat.
Can someone please guide me what am I missing ? I am using gcc compiler.
Thanks....
"I have compiled my source files to a static library with expat statically linked to it."
I'm fraid you haven't. A static library is not produced by the linker; no linkage is involved, so nothing can be linked to it.
A static library is nothing but a bag of object files in ar archive format.
When you are linking something that is produced by the linker - namely a program or a shared library -
you may offer such a bag to the linker. It will look in the bag and take out just the object files it needs to
carry on the linkage and link them into the target. The bag spares you the difficulty of
needing to know exactly which of the object files in it the linker will need, but the bag itself contributes nothing at all to the linkage.
Later
How can I get expat static library included in my utilities library, so that I only need to link my executable with a single static library. I don't want to extract the two archives and merge the object files together.
There is no other way of combining two ar archives.
Your resistance to linking libexpat is puzzling, without further context. It is available
through the package manager on any distro. You've made a library that depends on libexpat. Clients that link your
library will need also need to link libexpat. This is an utterly routine sort of dependency
that you should simply document and - if you are packaging your library - include
in the package dependencies. Almost invariably when we write new libraries we are augmenting the
libraries already available to our target users. If every library statically
incorporated all of its own dependencies then they would all be the size of an
operating system and of no practical use.
I'm tryng to figure out how to use a module of a DLL library in a fortran project,
still don't know how.
When I read different discussions concerning this, they all talk about using the .lib generated when the DLL was built,
Isn't a DLL a Library (like a .lib) but shared.
why do we need the .lib ?
When I need to build some third party library to be used in several of my projects under different version of MSVC, I usually build it for every MSVC version and for both Debug and Release configurations. That's what boost does, and that's what we have been done for our whole life in my team.
However, I still don't get, why couldn't I just build this library with like... whatever. All I need is function prototype and object code, right? Since I'm linking CRT statically, I have no external dependencies. But when I'm trying to link library built in Release under MSVC8 with my project in Debug under MSVC10 I have this annoying "already defined" linker errors which we all hate so much.
But why? Can I just "encapsulate" all this functions inside lib and do not export them so that my project will take only what it needs from the lib? Why can I have precompiled version of libpng and zlib which I can link in every project? Yes, they are not build using MSVC, I guess, but the still uses the same functions of CRT. So can anyone please explain in depth or share a link to some enlightened explanation of this issue?
Since I'm linking CRT statically, I have no external dependencies
Well, that's not true, you do have a dependency. On the static version of the CRT. Debug or Release, depending on your build settings. And it is an external dependency, the linker glues the CRT later, when the library gets linked. The code that uses the library also has a dependency on the CRT. And if the compile settings don't match then the linker barfs.
You isolate that dependency by building a DLL instead of a static link library. You must further ensure that the exported functions don't cause a CRT dependency. You can't return a C++ object from the standard C++ library and can't return a pointer to an object that needs to be released by the client code. Even passing structures is tricky since their packing is an implementation detail, but you usually get away with it. A good practical example is COM automation, it forces you into using a subset of types that are universal. Windows is rife with them and all these servers work with any version of the compiler or CRT. Even any language. This however comes at a cost, writing such a library isn't as simple or convenient as just throwing a bunch of code in a static lib.
I'm building a project which consists of two .net executables, and a class library with common components that the two executables share. For ease of distribution, I was hoping to be able to distribute the two executables without distributing the dll (grab & run distribution).
Is there any way to have visual studio compile the contents of the dll into each executable without manually copying the classes into each project (and thereby replicating the code in more than one place)?
Don't make it a DLL. Make it a static library instead.
Digging around on SO I found a duplicate question which stated the problem quite a bit more clearly than I did.
ILMerge seems to be the solution.
Static Linking of libraries created on C# .NET
I have a DLL project in VS 2008 Pro which uses OpenMP. I use /MT as 'code generation' option, because I want all my dependencies statically linked into my DLL, since I do not want to distribute many libraries to my clients - everything shall be included in this one DLL file. The problem is that my resulting DLL still depends on VCOMP90.DLL.
How can I get rid of this dependency?
Some information:
/openmp is set in compiler options
I statically link against vcomp.lib
include is set
using multithreaded library (/MT)
Thanks a lot for your help!
I don't think you'll be able to get rid of the DLL dependency - vcomp.lib is an import library for the VCOMP90.DLL - it's not a static library:
http://msdn.microsoft.com/en-us/library/0h7x01y0.aspx
It doesn't look like a static lib is provided.